SA Mechanical Engineer September 2012 by Promech Publishing

THE SOUTH AFRICAN MECHANICAL ENGINEER

VOL 62

September 2012

THE SOUTH AFRICAN MECHANICAL ENGINEER

VOL 62

September 2012

AN ENGINEER’S VIEW

The National Development Plan Chris Reay Chairman of the Working Committee: Communications (SA Institution of Mechanical Engineering)

In June last year, the commission released a diagnostic document which stated that the elimination of poverty and the reduction of inequality were the objectives of a long term plan, but that nine key challenges stood in the way. Let’s call these the Undesirable Effects or UDEs for short.

1. Too few people work. 2. The quality of school education for black people is poor. 3. Infrastructure is poorly located, inadequate and under-maintained. 4. Spatial divides hobble inclusive development. 5. The economy is unsustainably resource intensive. 6. The public health system cannot meet demand or sustain quality. 7. Public services are uneven and often of poor quality. 8. Corruption levels are high. 9. South Africa remains a divided society.

Any amount of political innuendo will not overcome that reality Then, in November, the commission produced a draft National Development Plan for 2030. It contained recommendations covering the following areas. Let’s call these the Desirable Effects or DEs for short. We can see that these are in effect the inverts of the UDEs, and hence become objectives or what we will classify as ambitious targets. 1. Create jobs 2. Education and training 3. Expand infrastructure 4. Transform urban and rural spaces 5. Transition to a low carbon economy 6. Provide health care 7. Build a capable state 8. Fight corruption 9. Transformation and unity Let’s take a reality check on the proposed elements of the plan. We can approach this with a mindset that has evolved from a fairly long exposure and many practical applications of the theory of constraints, commonly abbreviated to TOC. It is evident that this NDP challenge is a case of aspiring to a number of ambitious targets that not only require the full dependence on their specific necessary and sufficient conditions, but that such conditions can exist without any mutual conflicts.

Use the best

Intuitively, the NDP is doomed to failure primarily as a result of an historical lack of effective management execution in South Africa. Any amount of political innuendo will not overcome that reality. What we can only hope for is that the government, as the sponsors so to speak of the plan, will draw on the intelligence, skills, experience and proven competence of available resources to set up, design, articulate, prescribe and monitor the plans making up what we should in fact call a programme, as it will be a collection of interactive and dependent projects each requiring skilled planning and management execution. The best must be used, not the most politically favoured. There is one very fundamental factor that will render this programme so challenging that it should convince us of the need for the most radical, urgent, collective effort. I will simply call it the Rule of exponential projections. It is evident in reviewing the listed DEs that every one of them is essentially population growth rate dependent. From 2000 to 2011 the Mundi index shows that the growth has been 12,8% in net gain of population numbers, or an annualised rate of 1,2%. This moderately low (recent) increase in the population was due to the escalation in HIV/Aids driven deaths. How this will change in the next 20 years is an unknown, but it could increase if the treatment measures are effective.

A pipedream

30% of the current population is 14 years old or less and all reaching the job market age in this period. There are an estimated 4,7m unemployed persons in the employment spectrum at present, so a rough projection shows that we need to create about 4.7 m, plus those jobs to employ the 14 year olds, plus the result of the population growth over this period.

THE SOUTH AFRICAN MECHANICAL ENGINEER

continued on page 4

VOL 62

September 2012

AN ENGINEER’S VIEW

In my maths, the NPC vision to create 11 m jobs over the next 20 years means we shall have more unemployed in numbers than we have at present. So the elimination of unemployment and hence poverty would appear to be a pipedream and we question whether it has taken exponential growth into account. Clearly economic growth is required to create these jobs and it has to occur at a higher exponential rate than that of the population needing employment. How does one converge these two lines? We either limit the growth rate of the independent variable (population) or radically increase the dependent variable (economic growth rate). If not, the lines diverge and the problem becomes greater. Many goals are missed due to the prevalence of linear thinking.

Many goals are missed due to the prevalence of linear thinking Collapsed and underserviced

The ability to provide the management execution to all these components of the programme requires skilled and experienced resources (primarily technical: Engineers, Technologists and Technicians) to be available at the right level and numbers to implement the projects: infrastructure for example requires that the reinvestment into the assets of the infrastructure must equal the rate of depreciation just to remain static. Again we will find that the curves diverge if we cannot reverse the current trend in historical deterioration of these assets without replacement. The infrastructure is currently in a state of serious entropic decline with little evidence of major projects in the pipeline. If the growth rate of urbanisation which is a major factor in overload and breakdown of infrastructure exceeds the rate of infrastructure growth by only 3,5% per annum, the magnitude of collapsed and underserviced urban population with all its attendant troubles will double in 20 years.

THE SOUTH AFRICAN MECHANICAL ENGINEER

VOL 62

Hollow rhetoric

What are the simple fundamentals that must be followed in the big plan or programme? Firstly, identify the goal of each ambitious target of the programme, identify the constraints, subordinate to them, elevate them and keep following this process ensuring that interim pre-defined milestones are being met. Prioritise what will drive the throughput to meet the goal. Do what should be done and do not do what should not be done. Do not waste resources and time, for example changing town and road names, when the resources should be used to manage the required activities to achieve the programme objectives. Utilise the best available management and capacity to execute the processes. South Africa has a major constraint in the numbers of productive resources that it can apply to this pending challenge. Some sense must be brought into the skills space alone that reverses the current trend • to enforce misplaced affirmative action, • uses the experienced skilled (and ageing) work force, • raises compliance levels for entrance to learning institutions, • discontinues the employment of political appointees into roles instead of competent persons selected on merit, • reviews the negative impact of the labour laws, • formulates effective policy on small business development, and • identifies measurable, interim milestones over the next twenty years. If these issues are not addressed, then I have to say that the great plan will fail on the basis that reality is again being replaced with political imperatives that make the appeal of the planning commission to the public to join forces “to make miracles” nothing more than hollow rhetoric we have come so used to hearing. And the exponential rule waits for no-one.

September 2012

September 2012 VOLUME 62 NUMBER 9

On the cover: Atlas Copco Tel: (011) 821-9000 www.atlascopco.co.za

Contents Marine

POWER GENERATION TODAY

8 R5,8-million Yacht

19 A Scary Scenario Indeed! 27 Power Generation News

Cover Story 9 New Nitrogen Generators for Industry

Compressors, Air Motors & Vacuum Pumps 11 Energy Solutions with Compressors 13 Overcoming Scepticism Copyright All rights reserved. No editorial matter published in “SA Mechanical Engineer” may be reproduced in any form or language without written permission of the publishers. While every effort is made to ensure accurate reproduction, the editor, authors, publishers and their employees or agents shall not be responsible or in any way liable for any errors, omissions or inaccuracies in the publication, whether arising from negligence or otherwise or for any consequences arising therefrom. The inclusion or exclusion of any product does not mean that the publisher or editorial board advocates or rejects its use either generally or in any particular field or fields.

Monthly Column 15 Prominent Professionals

Opinion 17 Soapbox

Oils & Lubrication 29 Diesels Gets Complicated

Mills 36 Liners for Grinding Mills 38 Mills with a Difference

Regulars

3 An Engineer’s View 6 Institution News 16 SAINT 18 SAIT 40 Market Forum

The monthly circulation is 4 242

Produced by: PROMECH PUBLISHING, P O Box 373, Pinegowrie, 2123, Republic of South Africa Tel: (011) 781-1401, Fax: (011) 781-1403 Managing Editor Susan Custers Editor Kowie Hamman Circulation Catherine Macdiva Advertising Mark Bennett DTP Zinobia Docrat / Donovan Vadivalu Subscriptions Please email us at accounts@promech.co.za if you wish to subscribe to “SA Mechanical Engineer” at R405,00 (excl postage and VAT) per year; R1 020,00 per year for Africa/Overseas. Disclaimer PROMECH Publishing and The South African Institution of Mechanical Engineering as well as any other body do not take responsibility for the opinions expressed by individuals.

Printed by: Typo Colour Printing, Tel: (011) 402-3468/9 FSC (Forestry Stewardship Accreditation)

Official Publication of THE SA INSTITUTION OF MECHANICAL ENGINEERING and endorsed by:

 CORROSION INSTITUTE OF SA  SA PUMP MANUFACTURERS ASSOCIATION  SA VALVE AND ACTUATORS MANUFACTURERS ASSOCIATION  THE SA INSTITUTE OF TRIBOLOGY  NUCLEAR INSTITUTE  SA INSTITUTE FOR NON-DESTRUCTIVE TESTING  NATIONAL SOCIETY OF BLACK ENGINEERS  INSTITUTE FOR CERTIFICATED MECHANICAL AND ELECTRICAL ENGINEERS  SOUTH AFRICAN ASSOCIATION OF CONSULTING ENGINEERS  ASSOCIATION OF SOCIETIES FOR OCCUPATIONAL SAFETY AND HEALTH  THE SOUTHERN AFRICAN ASSOCIATION FOR ENERGY EFFICIENCY (SAEE)

THE SOUTH AFRICAN MECHANICAL ENGINEER

VOL 62

September 2012

THE SA INSTITUTION OF MECHANICAL ENGINEERING

Council 2012 - 2014 Office Bearers

President ............................................. KK Nyangoni (Kudzai) Vice President .............................................. D Findeis (Dirk) National Treasurer ........................,................. A Roos (Andre) Immediate Past President............................ G Barbic (George )

Branch Chairpersons

Central ................................................. S Murefu (Stephen) Eastern Cape ................................................ W Rall (William) KwaZulu/Natal ................................................. J Moto (John) Mpumalanga Highveld.............................. L Odendaal (Louis) Western Cape ........................................ Dr D Blaine (Debbie)

cordially invites YOU to their

Portfolios:

Communications/Strategic Planning/ Specialist Group..........................................CD Reay (Chris) Young Engineers Forum.........Prof B Collier-Reed (Brandon) Education: Universities of Technology....... E Zawilska (Ewa) Membership ........................................... E Zawilska (Ewa) Professional Development Programme...M Black (Malcolm) Technology Programme .......................... SZ Hrabar (Steve) To be confirmed..................................G Bartholomew (Bart)

Chief Executive Officer: Vaughan Rimbault National Office Manager: Anisa Nanabhay PO Box 511, Bruma, 2026 Tel: (011) 615-5660, Fax: (011) 388-5356 Email: info@saimeche.org.za Website: www.saimeche.org.za Membership: Central, Eastern Cape, Mpumalanga, Highveld & KZN: membership@saimeche.org.za Membership: Western Cape: saimeche.wc@vodamail.co.za

Company Affiliates Alstom Power Service SA

RSD a division of DCD-Dorbyl

Babcock Africa Limited

S.A.M.E Water

Bateman Engineered Technologies

Sasol Technologies

Bosch Projects

SEW Eurodrive

Fluor SA

Siemens

GEA Air-cooled Systems

SNC-Lavalin SA

Hansen Transmissions SA

Spicer Axle SA

Hatch Africa

Spirax Sarco SA

Howden Power

Technical Systems

Howden Projects

Thyssenkrupp Engineering

Industrial Water Cooling

Transvaal Pressed Nuts & Bolts

MBE Minerals (SA) (Pty) Ltd (previously KHD Humboldt Wedag SA)

Ultra-Flow Engineering Services

Megchem Eng & Drafting Services

Vital Engineering

Mod-U-Flow

Weir Minerals Africa

Osborn Engineered Products SA

Winder Controls

THE SOUTH AFRICAN MECHANICAL ENGINEER

2012 Dinner Dance Date: Time: Venue: Dress: Cost:

Saturday 03 November 2012 18:30 for 19:00 Wanderers Golf Club Cnr Rudd/Corlett, Illovo (Sandton) Black Tie/Traditional R4000 per table of 10 or R400 per individual ticket

After dinner the dance floor will be opened to boogie the night away to the fabulous music of Mac G, a dynamic duo covering a diversity of musical hits. Companies are invited to book tables of 10 guests. Sponsorship opportunities are available. R.S.V.P. by no later than 1 October 2012. Contact Lynne on (011) 615-5660/ central@saimeche.org.za

2007 Issues

We are appealing to any reader who has a full set of “SA Mechanical Engineer” 2007 issues to get in touch with us. We have a couple of issues missing and would appreciate anyone who can assist in helping us to “close the gap”. Susan Custers, Publisher Tel: (011) 781-1401 Email: samecheng@promech.co.za

Rotek Engineering

The Chairman and Committee of the Central Branch of The South African Institution of Mechanical Engineering

VOL 62

September 2012

THE SA INSTITUTION OF MECHANICAL ENGINEERING

Forthcoming Training Events Programmes, fees and registration forms may be obtained from Carey Evans on E-mail carey@saimeche. org.za or Tel. 031-764-7136. Also, detailed individual event programmes are available from Carey. Code

Abbreviated Title

Date – Start

Date – End

Region

C2512

Effective Management Roles

26 Sep 12

Cape Town

E0212

Boiler House; Safety Valves

3 Oct 12

5 Oct 12

East Rand

A0212

Boiler House; Safety Valves

10 Oct 12

12 Oct 12

Durban

E2912

Lubrication & Lubricants

17 Oct 12

East Rand

E61A2

Leadership & Management Roles

17 Oct 12

18 Oct 12

East Rand

E2912

Lubrication & Lubricants

17 Oct 12

East Rand

C5612

Problem Solving for Engineers

24 Oct 12

Cape Town

E5612

Problem Solving for Engineers

14 Nov 12

East Rand

A5612

Problem Solving for Engineers

21-Nov-12

Durban

In-House Workshops To obtain a comprehensive list of workshops that may be held In-House or to discuss your corporate training needs, kindly contact National Events Manager, Linda Robinson on E-mail linda@saimeche.org.za or Tel: 031 764 7136. Specific event programmes and a delegate registration form may be obtained from Carey Evans on Tel: 031 764 7136 or Email : carey@saimeche.org.za

Western Cape Branch Dinner and Dance

THE SOUTH AFRICAN MECHANICAL ENGINEER

VOL 62

September 2012

MARINE

R5,8-Million Yacht An Atlantis 38 open-class power yacht, one of the most desirable boats in the world, was the star attraction at the Johannesburg Boat Show held at the Nasrec Expo Centre in August.

he 11,62 -metre craft, built in Italy, is priced at a cool R5,8-million and took centre stage at the exhibition.

“I have heard the Atlantis 38 described as the upgrade to end all upgrades,” says John Broderick, CEO of Vanderbijlpark watercraft specialists, Broderick Marine, importers of the Atlantis range in South Africa. “With it’s sliding, retractable glass roof, superb attention to every-onboard detail, and potent dual Volvo stern-drive motors, this is indeed the ultimate for boating both in the inland regions, and on the ocean.” Other features of the exquisitely-finished boat include berthing for four adults, a retractable table that can be converted into a sun-lounger, a galley, an L-shaped saloon, and a shape that is evocative of power, grace and extreme agility. The twin stern-drive Volvo Penta diesel engines are

rated at 260 horsepower (191 kW) each, enough to propel the Atlantis 38 to a speed of close to 40 knots. A 760-litre fuel tank ensures that long cruises are easily possible with this craft. “The beauty about this craft is that despite being large enough to carry 12 passengers, it requires no special skills to pilot, because it is so nimble,” adds John, who is certain that there is a strong market for boats of this type in South Africa. The Atlantis 38 was one of a host of new boats and marine lifestyle gear showcased at the Johannesburg Boat Show. “All the major players in boating were there, including both the importers and local boat builders with the likes of Tige, Cobalt, Mastercraft, Malibu, Chris Craft, Honda, Yamaha, Suzuki, Mercury and Evinrude.” Byron Colantoni, Tel: (011) 494-5006, Email: byron@@sashows.com, www.johannesburgboatshow.co.za

The art of drilling

Atlas Copco understands the importance of reliable, high-pressure compressors that are cost effective and easy to maintain. Our DrillAir™ compressors deliver high capacity and high pressure, effectively allowing you to drill deeper and larger holes at fast penetration rates, with higher productivity. Atlas Copco Construction Technique P O Box 14110, Witfield 1467 Tel: (011) 821 9000, Fax: (011) 821 9106/7 www.atlascopco.co.za

Visit us at

Stand G21 Hall 6

THE SOUTH AFRICAN MECHANICAL ENGINEER

VOL 62

September 2012

COVER STORY

New Nitrogen Generators for Industry The next time you open a bottle of wine and out comes a sparkling clear liquid, with a rich bouquet, tasting nothing like old vinegar, it’s probably thanks to purified nitrogen gas used in the bottling process which prevents oxygen from spoiling the wine once it’s corked up.

itrogen gas has a wide variety of applications, including serving as an inert gas replacement for air where oxidation is undesirable such as preserving the freshness of packaged or bulk foods by delaying rancidity and other forms of oxidative damage in packaged potato chips, nuts, snack foods and salads, for example.

Charl Ackerman, business line manager of the industrial air division

Industrially it is used on top of liquid explosives such as paint and solvents as a safety measure. It’s also used in the production of electronic parts such as transistors, diodes and integrated circuits to prevent oxygen and moisture build-up, and even in fuel storage systems and aircraft tanks to reduce fire hazards.

On-tap gas

One of the methods of producing nitrogen gas is a compressor system combined with a nitrogen generator to literally proPieter van Wyk, business line manager of oil duce compressed purified nitrogen-on-tap whenever free air

it is needed. “SA Mechanical Engineer” speaks to Charl Ackerman, business line manager of the industrial air division at Atlas Copco, which is now introducing a new range of PSA nitrogen generators to the South African market. “Instead of having bottled nitrogen in a gas cylinder which has to be refilled regularly, a nitrogen generator system ensures continuous availability at the desired purity level, cost effectively,” he says. “For high purity gas production of up to 99.999%, we utilise pressure swing adsorption (PSA) technology, but we also have a range of models with membrane technology for applications which don’t require high purity gas levels, usually around 95% purity.”

Instead of having bottled nitrogen in a gas cylinder which has to be refilled regularly, a nitrogen generator system ensures continuous availability PSA technology

In essence the PSA nitrogen generator separates Nitrogen and Oxygen molecules This takes place in a two-phase process, utilising compressed air. In the first phase, the adsorption phase, the pressurised air flows through the columns filled with a carbon molecular sieve (CMS). By pressurising the vessel, oxygen molecules are adsorbed by the CMS, while nitrogen molecules pass on because they’re larger. The sieve continues to adsorb oxygen until a saturation point is reached. In the second phase, the regeneration or desorption phase, the pressurised air stream is cut off allowing the oxygen to leave the vessel at low pressure. The two vessels work together to produce a nearcontinuous flow of nitrogen gas, by alternating the adsorption/regeneration duties, which then goes to a receiver from which it is piped to the application in the same way that compressed air is piped to various outlets. The nitrogen piping is usually green while compressed air piping is blue, so there can

THE SOUTH AFRICAN MECHANICAL ENGINEER

VOL 62

September 2012

COVER STORY

be no confusion especially if both are being piped through a factory.

Membrane technology

The nitrogen generator uses membrane air separation to produce nitrogen. The membrane consists of a bundle of hollow fibres with a polymeric structure which allows nitrogen to pass through while other gases such as the oxygen and water vapour permeate. The compressed air enters the inlet, nitrogen exits at the outlet and the oxygen is vented.

The membrane consists of a bundle of hollow fibres with a polymeric structure which allows nitrogen to pass through while other gases such as the oxygen and water vapour permeate “Membrane technology generates nitrogen gas purities of between 95 and 99%, we have machines with capacities going up to 200 cubic metres per hour,” says Charl. “This cost-effective solution is suitable for applications such as tyre inflation for a fleet of trucks. “In the PSA range, our capacity increases to around 1100 cubic metres of nitrogen an hour, delivering nitrogen of a purity ranging from 95 up to 99.999%, suitable for many applications including the pharmaceutical, food processing, metal and the oil and

gas industries,” he elaborates. “Very often users temporarily want a lower purity say 97%. With our system, you can produce this when required, but if using gas cylinders, you’re stuck with a single level of purity determined by the supplier.”

Special applications

“We can customise a nitrogen generator solution around our range of oil free compressors as well,” adds Pieter van Wyk, business line manager of oil free air at Atlas Copco. “An entire package can, for example, be engineered for application in the petrochemical or oil and gas industries.” Over and above the convenience factor, nitrogen on tap has many other advantages over using gas cylinders. Charl remarks in conclusion, “You can never run out of gas. Due to the high efficiency of the technology, running costs are low and there are no additional costs related to ordering, refilling or delivery and the unit is virtually service-free. The pay-back time is often less than a year.” Charl Ackerman, Atlas Copco, Tel: (011)821-9000, Email: charl.ackerman@za.atlascopco.com

THE SOUTH AFRICAN MECHANICAL ENGINEER

VOL 62

September 2012

COMPRESSORS, AIR MOTORS AND VACUUM PUMPS

Energy Solution with Compressors

The Demag VK 32C number 1 compressor that Rockwell Automation upgraded for Harmony Gold Mining Company’s number 7 and 8 shafts in Evander

Compressor systems were upgraded at Harmony Gold Mining Company Limited’s (Harmony) number 7 and 8 shafts in Evander. The upgrade was the result of the mine’s optimisation strategy in Evander and its drive to do so in the most energy-efficient way possible.

ccording to Riccardo Fachin, Rockwell Automation’s Systems & Solutions Business Project Manager, saving energy with compressors is often an under-utilised solution in industry, so this was a unique project to showcase its possibilities.

At unity

“We held discussions with Harmony’s Electrical personnel on what extra equipment should be installed with a view to measuring and reporting energy usage and eventually, savings,” explains Riccardo.

Automatic solid state DC excitation was accomplished on the existing synchronous motor with the use of a DC control and power monitoring system. “This system has proven its reliability where the power factor is being held at unity under all load conditions.”

Saving energy with compressors is often an underutilised solution in industry, so this was a unique project to showcase its possibilities

The real test was to envisage the control and instrument system and prove not only energy saving, but provide a true model of the much-needed surge control despite the fact that there was no information on the existing system.

The number one compressor is a 1987 Demag VK 32C with a discharge pressure of 6.7 bars and an inlet of 35 000 cubic metres per hour, and the synchronous motor 2 900KW 6,6KV needed an upgrade on the electrical MV switchgear, as well as the control system.

“The mechanical upgrade essentially consisted of new electrically-controlled inlet and outlet vane valves for surge control. The electrical upgrade consisted of new 6.6kV switchgear, but we reused the oil cooled reactor starter,” says Riccardo.

Appropriate control

Rockwell Automation engineers implemented a new Allen-Bradley ControlLogix PAC (programmable automation controller), complete with GEM standard ICS-Triplex for compressor control software

THE SOUTH AFRICAN MECHANICAL ENGINEER

VOL 62

September 2012

COMPRESSORS, AIR MOTORS AND VACUUM PUMPS

into a new motor control centre (MCC), ready for connection to instruments. The ICS-Triplex compressor control software allowed engineers to easily calculate and load the most appropriate surge control for the conditions that the compressor number one worked at, together with two other compressors. The control of the inlet vane through the surge control constituted a considerable energy saving. To collect all relevant information indicating aspects such as pressures, temperatures, power factor, power usage, airflow, trips and alarms, the SCADA system (FactoryTalk View) was installed.

Significant

During the first month of operation, the energy saving from compressor number one was already significant. Rockwell Automation began work on the second compressor, with â&#x20AC;&#x153;plans afoot to upgrade other compressors working on the same manifold. Therefore, the ICS-Triplex software with an Allen-Bradley ControlLogix will allow for proper load sharing or shifting between compressors and we envisage an even more substantial saving,â&#x20AC;? concludes Riccardo. The FactoryTalk View that was installed on the compressor collects all relevant information indicating aspects such as pressures, temperatures, power factor, power usage, airflow, trips and alarms

THE SOUTH AFRICAN MECHANICAL ENGINEER

VOL 62

Riccardo Fachin, Rockwell Automation, Tel: (011) 998-1000, www.zarockwellautomation.com

September 2012

COMPRESSORS, AIR MOTORS AND VACUUM PUMPS

Overcoming Scepticism The fact that China’s labour costs are the lowest in the world has encouraged many well-known OEMs to open factories in China to manufacture their premium branded products. This means that other manufacturers can now source premium brand components and have their products assembled in China under their own brand at a very competitive price.

his is how the compressor range from the South Korean company Bumatec is made, a range which is now available in South Africa through Sudo Air in Johannesburg.

Combining the best of the best

“SA Mechanical Engineer” speaks to Sean Gertzen of Sudo Air, about the features of their wide range of rotary screw compressors. “The company has been around since 2005, but we only took on the agency for the Bumatec range one year ago,” he says. “Although they have the full power range up to 355 KW, we’re generally stocking machines up to 45 KW off-the-shelf while gradually building up stock of the bigger machines as the product becomes known in heavy industry and mining.

Sean Gertzen of Sudo Air

Being an Asian product, we have to put in extra effort to market the range because many people are sceptical about quality and our very competitive pricing “Being an Asian product, we have to put in extra effort to market the range because many people are sceptical about quality and our very competitive pricing,” says Sean. “Yet the components in our machines are sourced from the likes of ABB, Siemens, Cummins diesel motors, Tamrotor air ends and valves from Hoerbiger, all well known brands in the compressor industry internationally. We specifically selected

Components are sourced from the likes of ABB, Siemens, Cummins diesel motors, Tamrotor air ends and valves from Hoerbiger

THE SOUTH AFRICAN MECHANICAL ENGINEER

VOL 62

September 2012

COMPRESSORS, AIR MOTORS AND VACUUM PUMPS

Bumatec after personally visiting the factory, and satisfying ourselves with the build quality and workmanship in the manufacturing of these compressors compared with many other compressor manufacturers we visited in Asia. Moreover many of the components utilised in Bumatec compressors can be serviced through the local channels of the various suppliers.”

Having control of the speed of the compressor through frequency control reduces energy consumption significantly Practical experience

To get their product known among users, Sudo Air also has a lease-to-own offering. Sean explains, “We invite people to come around and inspect the machines, see how they run and witness the quality first hand. If they’re interested, we offer a rental scheme over a couple of months under which they can simply return the machine if they’re not happy with the performance. If they’re satisfied with our product after an These compressors are equipped with an intelligent controller agreed time, they simply pay the balance system which constantly monitors its operating status to own the machine. All the compressors we’ve leased out in this way have turned into a Control sale without a single one coming back because of These compressors are equipped with an intelligent an unhappy customer.” controller system which constantly monitors its opSudo Air’s complement of staff are all specialists in their respective areas with a combined experience of more than 60 years in the compressor industry. “A large number of our management staff have held senior managerial positions with compressor OEMs locally and internationally,” says Sean. “We utilise state of art testing, balancing and vibration equipment, all contained in-house to ensure that all problem areas are pin-pointed and rectified at the optimum cost efficiency to our customers. Our workshops are manned by a 24-hour a day service team to provide customers with a professional service.”

Machine features

The Buma range of compressors have all the technical features and options expected of modern compressors, especially when it comes to energy saving aspects. “We have a variable speed drive (VSD) option for this range of compressors,” explains Sean. “Having control of the speed of the compressor through frequency control reduces energy consumption significantly because the machine then runs according to the air demand from the factory floor.” At the heart of any screw compressor are the rotors. “In addition to the speed control option, the Buma range utilises larger rotor technology combined with low rotational speed which is proven to improve the efficiency of screw compressors in general which also results in longer life for the machine .”

THE SOUTH AFRICAN MECHANICAL ENGINEER

VOL 62

erating status. The system has overload and phase rotation protection, constant oil and air pressure monitoring, as well as event history to name but a few of the key features. In Sean’s experience the biggest mistake people make when it comes to compressors is under sizing the machine for a specific duty. “Sizing the right machine after a proper air audit is very important,” he says in conclusion. “That’s where VSD technology comes in very handy. Whenever possible we always suggest a dual installation where you have a base-load machine while running a VSD machine in conjunction to provide the top-up as demand fluctuates through the operational cycle of the factory.” Sean Gertzen, Sudo Air Compressor Services Tel: (011) 025-4420, Email: sean@sudoair.co.za

Get longer exposure Book Now for Nov/Dec 2012 • • • •

HVAC Steam, turbines and boilers Bearings and lubrication Power Generation

Contact Mark Bennett on Tel: (011) 781-1401, or E-mail: samecheng@promech.co.za for further details

September 2012

MONTHLY COLUMN

Prominent Professionals Jaco Smit Pr Eng, B.Eng, M.Eng (Mech), MBA, CMRP, GCC:

induced draft fans on the boiler system. Our new design saved so much in energy and reduced downtime for repairs, that the pay-back time was less than two years. Not only did we make dramatic changes to the blade design of the fan, we also made it easy and quick to replace in terms of maintenance.

Project Leader, Sasol Site Services

Academic School

High School Gimnasium, Potchefstroom.

Any awards

Graduate studies

Within Sasol our Refining Maintenance team won the best maintenance engineering award.

Mechanical Engineering, University of Potchefstroom.

Future – a concept, a dream or a wish

Post-graduate

I don’t have a specific dream project in mind because all of the many projects we’ve done over the years at Sasol were unique, worldleading projects with each always having some Jaco Smit of Sasol special aspect to it. I always strive to develop Professional Bodies new plant concepts so that it runs and operates ECSA registered; a certified Member of SMRP (Society of in harmony as a whole to achieve what it was designed for. maintenance and reliability practitioners) in the USA. Masters degree in mechanical engineering at University of Potchefstroom specialising in CFD, (computational fluid dynamics).

Projects

Career Path

Most challenging

First employer

MTech Engineering as a database programmer for a year and designing, building, installing and maintaining swimming pool heat pumps.

Growth path

While at Mtek, I also worked for the University of Potchefstroom until joining Sasol. There, I worked through the ranks from assistant engineer through to area manager of Reliability engineering. Through the years I worked in all engineering sections, from steam generation maintenance engineer, to operations production engineer while developing the mechanical maintenance side of the refining plant. I then moved on to reliability engineering and I am now doing maintenance integrity of our logistics division in Shared services.

Present employer and position

For the past 18 years, I have been employed at Sasol, currently as a project manager in charge of a team managing projects valued in the region of R2.5 billion.

Most rewarding

Each project is rewarding, but one that stands out is the unleaded high octane fuel project. It is very satisfying to start with an open piece of land and end up with a huge plant which produces a new product line entirely. Another, which is more on a continuous basis, is planning our annual shutdowns which are particularly challenging. Each one is a triumph when you get it done without injuring anyone, restoring integrity, on time and within budget.

Commentary Are there shortcomings in the Mechanical Engineering Industry in South Africa?

Achievements A project

The current project we’re working on. It has many aspects within the company, such as compliance to environmental standards, to enhance safety in general and to optimise logistics within the whole enterprise. It comprises of several separate projects worth hundreds of millions each, which my team has to control as one project.

The most memorable project is many years back in Sasol’s main steam plant where we modified and upgraded the

Although mechanical engineering is often regarded as a necessary evil, the world can’t do without us. Apart from a huge shortage of engineers there aren’t really shortcomings in the industry.

THE SOUTH AFRICAN MECHANICAL ENGINEER

VOL 62

September 2012

SA INSTITUTE FOR NON-DESTRUCTIVE TESTING

∑∑∑∑∑∑∑∑∑∑∑∑∑∑∑∑∑∑∑∑∑

Southern Africa Section of ASNT Level III Examinations

he American Society for Nondestructive Testing (ASNT) Southern Africa Section was reinstated three years ago. One of the key areas that the committee decided to focus on was providing a facility for existing and prospective Level IIIs to allow them to write ASNT Level III examinations at an affordable price, as travelling to an overseas venue to write is exceptionally expensive and cumbersome. This venture greatly increased the number of qualified Level IIIs in the country. At the end of 2009 there were only nine but after running three consecutive sessions of examinations successfully, the number

Ben Beetge

has now increased to 30 with more expected. The first examination session was held in May 2010 with 67 papers written by 22 candidates (many of whom were existing Level IIIs who wanted to add one or two more methods to their existing qualifications). The second examination session was held in January 2011 with 46 papers written by 22 candidates. This was followed by another examination session in September 2011, where 34 papers were written by 14 candidates. The last session was during June 2012 where 31 papers were written by 12 candidates.

Valuable experience

Refresher sessions were facilitated prior to the first examination session in May 2010 by Argyll Ruane from the United Kingdom, but since then all refresher courses have been presented by local Level IIIs. This has allowed many Level IIIs the opportunity to not only obtain experience in the various methods for which they present courses, but also to gain valuable re-certification points. Further recertification points were also obtained by local Level IIIs who acted as assistant proctors during the examination sessions. Through this initiative, the Southern African Section of ASNT has assisted many NDT personnel in attaining their goals cost effectively. Ben Beetge, Section Chair, SA Section of ASNT SAINT, Tel (011) 719-5717, Email: saint@saint.org.za, www.saint.org.za

THE SOUTH AFRICAN MECHANICAL ENGINEER

VOL 62

September 2012

∑

OPINION

Soapbox On his rounds, Kowie Hamman, our Editor, is conducting an informal survey on the lighter side of engineering. We follow up from last month with two pertinent questions.

Willem Sullivan of Hansen Are there aliens in outer space?

No, the mechanics to do it is simple enough.

Greg Perry of SEW

I don’t think so but if it was, it was a great production!

Brian Volk of PHC Projects

I doubt it, it would be too difficult to maintain the lie.

Phildy Schlotz of DRA No, it was real.

Thalefang Mtombeni of Schaeffler I’d say it was faked.

Izak van Niekerk of Bell Equipment Of course not.

Are you for or against bean counters?

Chris Coetzee of Resonant Solutions No.

Chris Coetzee of Resonant Solutions

Rudolph Beer of Martin Engineering Yes.

Totally against them in an engineering environment. They have their place in society but should not be in control of an engineering concern.

Willem Sullivan of Hansen

Rudolph Beer of Martin Engineering

No, we are strange enough here. And I believe God only made us.

For.

Greg Perry of SEW

Technical product requires technical people to ensure the product is correct. Technical people cannot work with money so bean counters are perfect support for technical people. BUT if you do procurement only through a bloody bean counter, who does not understand Total Cost of Ownership or the difference between a 1kW motor and a 1MW motor, your plant will DIE a horrible, broken down death. So I am for them, but in the correct position. That is why I married an accountant.

From time to time there are aliens in outer space but then they come back to earth.

Brian Volk of PHC Projects Probably.

Phildy Schlotz of DRA

Space is a big place and therefore I won’t rule it out altogether at all.

Thalefang Mtombeni of Schaeffler Gosh, no, I don’t think so.

Izak van Niekerk of Bell Equipment No, only on mother earth.

Was the moon landing staged?

Willem Sullivan of Hansen

Greg Perry of SEW No comment.

Brian Volk of PHC Projects

As my brother and son are bean counters I have to be for them, but they should appreciate that somebody has to create wealth before it can be counted.

Phildy Schlotz of DRA I’m for them.

Thalefang Mtombeni of Schaeffler Chris Coetzee of Resonant Solutions No.

Rudolph Beer of Martin Engineering Maybe.

Against, purely because of the problems I’m having with them right now.

Izak van Niekerk of Bell Equipment

Do you drive your car looking in the rear view mirror only?

THE SOUTH AFRICAN MECHANICAL ENGINEER

VOL 62

September 2012

THE SA INSTITUTE OF TRIBOLOGY

New President David Beard arrived in South Africa from the UK in 1985, with a degree in metallurgy and science of materials from Oxford University.

Wits University.

e initially worked for the Chamber of Mines Research Organisation (COMRO) on various materials related projects, including water-powered rock drills, before moving on to become Technical Manager at Boart Longyear where he was involved in diamond drilling crown research and development.

David then moved on to Anglo American Research Laboratories (AARL) in Crown Mines where he established a used oil analysis facility, mainly for the gold mines. After four years he left to join CMS International, first David Beard as a Diagnostician and later becoming the Laboratory Director and Part Owner. After CMS was bought out, David joined Caltex in Rosebank in various technical support roles. During his eight years there, he obtained an MBA through

New 2012/2013 SAIT Executive Committee Les Barker: David Beard: Johnstone Chikwanda: Neels Coetzer: Johan de Koker: Gill Fuller: Dave Gamble: Sam Manamela: Shawn Pharo: Thomas Surmon: Patrick Swan:

Eskom DPB Consulting Sasol Oil Yellotec University of Johannesburg SAIT Secretary Davgam Services Bahlaloga Technologies Science Friction Total SA Aswan Consulting

THE SOUTH AFRICAN MECHANICAL ENGINEER

VOL 62

Looking for new challenges, David left Caltex to join Metropolitan Oils in Edenvale as Technical Manager but was soon promoted to Managing Director, a role he fulfilled for almost three years, until leaving in 2011 to establish himself as a consultant. His company is called DPB Consulting (Pty) Ltd, and he is currently doing contract work for Sasol and ALS Chemex. David is married to Sue and they have two teenage sons, Jonathon and Thomas. He enjoys running marathons and has completed eleven Comrades and twenty Two Oceans as well as international runs like the Paris and London Marathons. When not running, David restores and races old cars, especially Triumphs. David has been on the committee of the SAIT for ten years in various capacities and has now been elected President. He has a particular interest in encouraging people to sit the STLE CLS exam and runs the SAIT exam preparation courses. SAIT, Tel: (011) 802-5145/6, Email: secretary@sait.org. za/admin@sait.org.za, www.sait.org.za

“LUBRICATION ENGINEERING”

5 day course on Principle & Technology of Lubrication Engineering 17 to 21 September, Jhb

“SAIT CLS STUDY COURSE” 21-22 November 2012, Jhb

STLE-CLS, OMA & CMFS EXAMS Friday 23 November 2012, Jhb

AIST “The Lubrication Engineers Manual” 4th Edition Available from SAIT

September 2012

POWER GENERATION

POWER

GENERATION PROMECH PUBLISHING Tel: (011) 781-1401 Fax: (011) 781-1403 Email: samecheng@promech.co.za Website: www.promech.co.za Managing Editor: Susan Custers Editorial: Kowie Hamman Advertising: Mark Bennett Circulation: Catherine Macdiva DTP: Zinobia Docrat/ Donovan Vadivalu Disclaimer PROMECH Publishing does not take responsibility for the opinions expressed by individuals.

TICKER TAPE

All rights reserved. No editorial matter published in “Power Generation Today” may be reproduced in any form or language without written permission of the publishers. While every effort is made to ensure accurate reproduction, the editor, authors, publishers and their employees or agents shall not be responsible or in any way liable for any errors, omissions or inaccuracies in the publication, whether arising from negligence or otherwise or for any consequences arising therefrom. The inclusion or exclusion of any product does not mean that the publisher or editorial board advocates or rejects its use either generally or in any particular field or fields.

T O D A Y

A Scary Scenario Indeed! In place of our usual “Power Generation Today” feature article, we have published a letter from one of our readers refuting the claims made about the advantages of heat pumps, as published in the article. We think it makes for interesting reading.

ith reference to the article entitled “Heat pumps for residential use” which was published in your June 2012 Volume 62 edition (pages 21 to 23), I would like to comment as follows:

It is a bit like placing a brick on the gas pedal of a V8...it’s going to fail When reading this article, I am struck by the constant 'fudging' of the numbers which we see time and time again by those selling heat-pumps. The one fact that comes across to the better informed, is the glaring lack of knowledge exhibited. Now before you bin this letter, let me just say that I have been in the hot water industry for the last 37 years, and installed probably one of the first commercial sized heat-pumps in a retirement home 25 years ago, a Hitachi 40 Kw, so heat-pumps have been around for a long time. I removed this heat-pump

four months later due to non performance, and replaced it with a solar system - no more issues! It is of great concern that we witness the total confusion caused by the promotion of heat-pumps in South Africa today. Here I lay the blame squarely at Eskom's door, due to the manner in which they 'willy nilly' gave heat-pumps subsidies with absolutely NO performance testing, SANS Standard or SABS Mark to measure against. In other words, there is NO heat-pump in South Africa with the SABS Mark of Approval! In the solar industry, at great cost to the supplier, all the products on the subsidy program had to be tested against a local standard SANS 1307 prior to being permitted on the program... so what happened with the testing on heatpumps? Double standards to say the least!!

Bad quality

We constantly hear that heat-pumps can save 60% of water heating bills. Is this possible? Maybe yes, if each day was an

Renewable-energy developer MetroWind has reported that its R550-million 27 MW wind farm at Van Stadens, in the Eastern Cape Province is set to start supplying power to the Nelson Mandela Bay municipality by August 2013.

The eThekwini municipality pilot project with its first set of solar-powered traffic lights has been unveiled. The project uses CIS solar modules to power traffic lights. The pilot is being implemented by ZRW Mechanika and its international partner, Saint Gobain.

Community structures can be created around used oil streams to provide additional markets and formal employment opportunities while sustainably producing biodiesel. Green Fuels biodiesel plants are simple to operate, require little energy and are modular, ranging from 3 000ℓ a day to 20 000ℓ a day.

The South African National Energy Development Institute, launched in July 2012, will stimulate home-grown green energy innovations. The new entity will seek to stimulate the research and development of indigenous green-energy innovations.

THE SOUTH AFRICAN MECHANICAL ENGINEER

VOL 62

September 2012

POWER GENERATION

optimum weather day, with low humidity and high ambient temperatures. This certainly is not our year round weather conditions, so to claim a COP of 3:1 is nonsense - it will at best case average out at approximately 1:1.5! This, by the way, is assuming you have a quality machine. Let's talk about quality. A large majority of the cheap heatpumps coming into South Africa from the East were designed as underfloor heaters, with a set point of 45 degrees. So to raise the temperature to the required 55 degrees, the pressure has to be raised from the designed 18 bar to 38 bar, plus the refrigerant has to be changed to, in some cases a blend of butane, yes, lighter fuel! If you make the compressor operate at this level, it is a bit like placing a brick on the gas pedal of a V8... it's going to fail.

TICKER TAPE

Another point that heat-pump suppliers know little about, is the use of sanitary condensers in heatpumps. It’s essentially a condenser which, when it fails, does not contaminate the water which is being heated. When this happens to a heat-pump

Renewable energy is potentially one of the biggest investment areas in the Western Cape. Nils Flaatten, chief executive of Wesgro, said that it is expected that between 40 percent and 50 percent of wind power projects in South Africa and 15 percent of solar energy projects will be set up in the Western Cape, where the provincial government hopes to generate 10 percent of the area’s energy needs from renewable sources by 2014. The downsized full-hybrid system used in the Yaris, from Toyota South Africa Motors, combines a 1,5ℓ petrol engine with a light, compact electric motor, transaxle, inverter and THE SOUTH AFRICAN MECHANICAL ENGINEER

VOL 62

with no sanitary condenser, it is impossible to remove the smell of hot oil from your hot water taps. For this reason, both Australia and New Zealand do not allow non sanitised condenser units, but in South Africa, anything goes!

Heat-pumps versus Solar water heating

Unfortunately, the 'studies' undertaken on this subject have mainly been undertaken by the heatpump 'camp' which is why they are very selective about costings etc. A classic example is where the heat-pump is compared with a solar system in price. A solar system consists of a solar geyser and solar panel/s, whereas a heat-pump is a stand alone unit which is connected to the household's geyser. In the 'study', there is therefore no allowance made for a geyser cost for the heat pump. Another misconception that is bandied about by the heat-pump salesmen, is that the sun does not shine at night, therefore there will be no hot water for a shower in the morning unless the electrical element switches on, thus costing the homeowner

battery pack. The Yaris hybrid produces zero emissions 66% of its commuting time on the road. Sustainable energy specialist Bluhm Burton Energy is building a new concentrated power plant at power utility Eskom’s facility in Rosherville. The CSP collector uses the linear Fresnel configuration and tracks the sun with large glass mirrors mounted on a steel support structure. The sun-tracking and mirror-control system has been locally developed and extensively tested on the prototype.

September 2012

POWER GENERATION

more money. A good quality solar water heating system that has been correctly sized will store enough hot water in the well-insulated solar geyser for showering first thing in the morning. The system is designed to supply 24 hours of hot water from 6 hours of sunshine. The company I started 35 years ago, has undertaken numerous industrial solar water heating installations where we have removed the heat-pumps and replaced them with solar systems. On page 20 is a graph that has been prepared by an independent measurement and verification company for a retirement home in Durban, where the heat-pump was replaced by a 6 000 litre solar system. The green line is the heat-pump base line, the red line is the solar base line and the blue columns are the daily savings in kWh. This clearly shows a 50% saving with solar against a heat-pump. If the heat-pump performed as advertised, there would be no change in the electrical consumption.

I am struck by the constant ‘fudging’ of the numbers Scary scenario

With reference to the last paragraph in your article where you state that the ultimate would be a solar system backed up by a heat-pump, tests that have been run at our testing facility, have shown that when using a heat-pump with a solar system, similar electrical

SAEE-10th Anniversary Special Commemorative Issue In celebration of its 10th anniversary, the SAEE (South African Association of Energy Efficiency) has appointed “SA Mechanical Engineer” to publish its SAEE 10th Anniversary Special Commemorative Issue. Help us highlight the dynamic work the SAEE has undertaken in the field of Energy Engineering, Energy Management, Renewable and Alternative Energy, Power Generation, Energy Services, Sustainability and all related areas by advertising in this Special commemorative publication.

X XA4 full page full colour R14 000.00 X XHalf page horizontal full colour R10 000.00 X XQuarter page full colour R7 400.00 X XSpecial Position: Front Cover including design and layout and four ‘strip ads’ R22 000.00

All rates are inclusive of advertising agency commission BUT exclude VAT and any production charges. Advertising space booking deadline is 5th October 2012 and final complete material deadline is 12th October 2012.

This issue will be given out at the energy efficiency@ work convention in November 2012 and by the SAEE at its other events in future years.

4 300 copies will also be mailed together with the Nov/Dec 2012 issue of the “SA Mechanical Engineer”.

Contact Mark Bennett on 084 396 8451 Tel: (011) 781-1401, Fax: (011) 781-1403 E-mail: samecheng@promech.co.za Website: www.promech.co.za

THE SOUTH AFRICAN MECHANICAL ENGINEER

VOL 62

September 2012

POWER GENERATION

consumption to that of an electrical element is used and if anything, marginally less on the heat pump. Net conclusion, is that to fit a heat pump with a solar system is not cost effective. The element runs for 1 hour and the heat-pump runs for 2.5 hours.

TICKER TAPE

Finally, a scary scenario to consider: 'Joe Public' buys a heat-pump from a local plumber; after six months there is a catastropic failure, and 'Joe' then calls his insurance company. They inspect his house and see that the heat-pump is a non SABS product and refute his claim, as it is against SA Building Regulations to install any non SABS product in your home/factory etc. 'Joe' then goes back to the plumber, and says that in terms of the Consumer Protection Act, he has to fix the

Solea Renewables has started construction on the first offgrid photovoltaic plant in Southern Africa, near Thabazimbi, due for completion by the end of October. Covering close to 2 ha, the plant will consist of about 4 170 panels, each generating 240 W. The Malawi hydroelectric project schedule revised for late 2013 completion. Malawi currently faces power supply constraints, with its peak supply pegged at about 250MW. A most recent study estimates that the country loses $4215.6 million a year owing to power outages.

THE SOUTH AFRICAN MECHANICAL ENGINEER

VOL 62

damages to his home. The plumber is an opportunist and had bought a container load of heat-pumps at a Chinese Trade Show and cannot afford to fix 'Joe's' home. He closes up shop and disappears. In desperation, 'Joe' phones Eskom and says that he fitted a heat-pump as Eskom had endorsed it with a subsidy, so please could they come around to fix it. Eskom's response is to tell him to go and check point 6 on the subsidy form, where it states that they take no responsibility for the performance or quality of the heat-pump, and that the supplier does. So where does this leave 'Joe Public'? A scary scenario indeed! Regards, Graham Mundy, 076 7300 291

Donâ&#x20AC;&#x2122;t Miss the Buyers Guide 2012/13

Contact Mark Bennett on Tel: (011) 781-1401, or E-mail: samecheng@promech.co.za to book your advertising space

September 2012

POWER GENERATION NEWS SKF have announced targets for their new climate strategy and have partnered with the WWF in their Climate Savers Programme. The SKF climate strategy includes aggressive targets for reducing greenhouse gas (GHG) emissions for SKF, its suppliers and logistics operations, as well as from its customer solutions. To support its customers, SKF also announced the launch of the BeyondZero portfolio including products and solutions which will both improve energy efficiency and support more environmentally-friendly energy production. “With our new climate strategy, we intend to be a leader in our sector to reduce emissions from both our own operations, but also to lead the way in helping our suppliers and customers reduce their emissions,” says Tom Johnstone, SKF President and CEO. “We are very proud to join with WWF as the first industrial engineering company to be accepted into the Climate Savers programme and look forward to continue using our engineering knowledge to make the world a cleaner place for us all.” SKF and WWF agree that there is a substantial role for the business community to play as a driving force behind the transition to a low-carbon economy and intend to work together in the Climate Savers Programme to reduce SKF’s emissions of GHGs, with particular focus on carbon dioxide (CO2). The WWF Climate Savers program works with leading companies to cut CO2 emis-

Tom Johnstone, SKF President and CEO

Aggressive New Climate Strategy sions. The partnerships between WWF and corporations aim at delivering real, measurable and additional reductions in CO2 emissions. The targets set must be demonstrably more ambitious than previous targets communicated by the company, and should place the company ahead of its competitors in terms

of reducing greenhouse gases. Outside experts monitor and verify compliance with these agreements. SKF South Africa (Pty) Ltd, Tel: (011) 821-3500, Fax: 011 821 3501, Samantha Joubert, SKF SA, Email: samantha.joubert@skf.com, www.skf.co.za

Few Fatalities "The reality is that the number of nuclear disasters is far less than those that occur at coal mines," says Philip Lloyd, research professor at the Energy Institute of the Cape Peninsula University of Technology. "On average 5000 people die annually because of accidents in the coal mining industry. In contrast, according to the World Health Organisation, in sixty years of nuclear power use globally, we have had 58 immediate deaths attributed directly to the Chernobyl disaster and 250 lives that were shortened because of the event. At Fukishima there were no deaths, but some people were exposed to radiation and their lives may be slightly shortened. You will have to look quite hard at the

to fully substitute coal or nuclear. "To produce 9.6 gigawatts with wind you would require about 22 500 two-meagawatt turbines at a 20% load factor," explains Philip. "The technical data behind the Integrated Resource Plan2010 gave a cost of R14500/kw installed, so 45 000 MW would cost R650 billion"

nuclear power sector to find fatalities that match those in the coal industry." Phili points out that the new nuclear plants will be built at the coast where seawater is used to cool it down. "Engineers have had to reverse the flow Philip Lloyd of the upper Vaal river to keep the coal-fired power stations like Duvha and Matla in Mpumalanga cool," he says. "This kind of engineering is not needed at the nuclear plants."

"There is an undeniable link between wealth creation and the supply of power. It is clear that the planned coal and nuclear power plants are part of the solution to South Africa's energy crisis"

Some experts argue that renewable energy sources should rather be investigated. But, says Philip these resources are simply not yet viable as an option

Energy Institute of the Cape Peninsula University of Technology, Philip Lloyd, Tel: (021) 460-4216, lloydp@cput.ac.za, Web: www.cput.ac.za

THE SOUTH AFRICAN MECHANICAL ENGINEER

VOL 62

September 2012

POWER GENERATION NEWS

Data Centre Cooling of conductive aluminium and some 6 metres in diameter. Half of the wheel is exposed to outside air, and the other half to the data centre air. The cooler exterior air temperature is transferred into the building as the wheel turns. Because the inside half of the wheel is sealed from the outside, dust and other contaminants in the external atmosphere are not transferred to the interior of the data centre.

A revolutionary design for Internet Solutions’ 11th African data centre, opened in Randburg recently and known as Randview, will slash client power costs, increase their data centre productivity, and improve disaster resilience. It will also give clients greater connectivity flexibility by allowing competitor carriers to connect directly into the data centre.

Heat is extracted from the data centre interior Internet Solutions’ fourth to be built in KyotoCooling is simply the highest quality energy optimized cooling solution by means of a hot isle contained exhaust system the Gauteng area, the for data centres in the world today and the wheel-cooled air is Randview data centre has been designed to operate without compressor based airconditioning has delivered at volume to the racks. conventional airconditioning for all but a significant impact on a client’s data “Kyoto Cooling has been tested and the hottest time (9%) of the year. The centre costs,” says Barry Hatfield, In- proven in many different applications data centre will boast a power utilisa- ternet Solutions business development in Europe and, most publicly, in Sydney tion efficiency (PUE) of 1.4 versus the manager for cloud solutions. Airport in Australia,” Barry adds. industry average of 2.5. Randview’s very nearly free cooling has “Cooling is the largest item on a data centre bill, so reducing the need for

been achieved by the use of three Kyoto Cooling Cells, mechanical devices made

THE SOUTH AFRICAN MECHANICAL ENGINEER

VOL 62

Tel: (011) 575-1000, Email: info@is.co.za, www.is.co.za

September 2012

OILS & LUBRICATION

Diesels Get Complicated While heavy-duty engine lubricants have always played a critical role in terms of fleet maintenance and performance, a number of emerging global challenges are currently driving extensive research and development (R&D) in this space.

Key to abbreviations: HDDEO: heavy-duty diesel engine oil TBN: total base number SAPS: sulphated ash, phosphorous and sulphur EGR: exhaust gas recirculation PM: particulate matter DPF: diesel particulate filters NOx: nitrous oxide SCR: selected catalytic

ith both new technology requirements from OEMs and far stricter European and North American legislation influencing the market, Paul Evers, senior technologist: Shell Global Solutions, explains their impact on lubricant formulation and testing and the implications for OEMs when it comes to lubricant partnerships. In commenting on the current state of the heavyduty diesel engine oil (HDDEO) market, it is important to reflect on the primary requirements of these lubricants, namely to protect both the engine, as well as the oil. No matter the current or future lubricant market influencers, HDDEO must always prevent valve train wear, oil filter blockage, bearing corrosion, the formation of deposits on the turbocharger and intercooler, and piston ring and cylinder liner wear, as well as sludge build-up.

are typically met through the selected use of both base oil and additives. In order for the lubricant to protect itself, the antioxidants, pour point depressants, viscosity improvers, and anti-foam additives fulfil this function, while the dispersants and antiwear components protect both the engine and the lubricant, simultaneously. While addressing these requirements it is imperative, key market drivers also need to be considered

Clean pistons

The oil must also ensure piston cleanliness while simultaneously resisting oil oxidation and thickening. These are considered â&#x20AC;&#x153;standardâ&#x20AC;? (table-stake) requirements for lubricant formulators, and THE SOUTH AFRICAN MECHANICAL ENGINEER

VOL 62

September 2012

OILS & LUBRICATION

when it comes to lubricant formulation. At present, these market drivers include a combination of the latest OEM technology requirements (such as extended service intervals, extended equipment life, increased power output and fuel efficiency), as well as certain legislative requirements (such as Euro IV, Euro V and US07).

Shell had to develop new ways of testing its products Because lubricants have an active role to play in meeting both of these drivers, R&D has become an absolute necessity for companies that develop their own lubricants, as well as for the additive manufacturers that support them. Actively partnering with OEMs to ensure that product formulation

meets these standards, and accurate field testing has become imperative for oil developers, while OEMs are viewing partnerships with companies like Shell in a similar light.

ACEA 2008 specifications

The ACEA 2008 specifications have resulted in a number of new challenges for lubricant manufacturers with the Euro IV and Euro V test engines (which replaced the previous Euro II engines), and the US07 test engines (with high exhaust gas recirculation rates) each presenting their own unique problems. In the case of the new Euro IV and Euro V test engines running on B5 fuel for example, Shell conducted tests and identified challenges related to piston cleanliness, bore polishing, engine sludge, valve train wear and oil consumption. In contrast, soot loading (or soot-induced wear), piston ring and cylinder liner wear, valve train wear, engine sludge, bearing corrosion, and oil oxidation were critical issues for the new US07 test engines. In order to meet the demands of these engines, being their higher oxidation propensity, TBN (total base number) limits, and the chemical limits of SAPS (sulphated ash, phosphorous and sulphur), Shell had to develop new ways of testing its products. As a result, more layers had to be added to an already extensive testing regime for each productâ&#x20AC;&#x2122;s formulation.

Laboratory tests

In order to address the issue of valve train wear in the engines running on B5 fuel, for example, extensive laboratory testing needed to be done using the Cummins M-11 EGR (exhaust gas recirculation) engine, focusing in particular on valve bridge and crosshead wear. While testing the 50 hour soot generation phase (with 15% EGR, 1800 rpm and overfuelled), as well as the 50 hour wear phase (with standard timing, 1600 rpm and 9.5% EGR), which was then repeated for 300 hours, it was discovered that a soot level of 8% weight was the minimum requirement for this engine. Table 1 outlines the performance of a Shell SAE 10W-40 oil when tested against the API CI-4 limits of this engine. This type of test alone is insufficient to determine the effectiveness of

THE SOUTH AFRICAN MECHANICAL ENGINEER

VOL 62

September 2012

OILS & LUBRICATION

oils in meeting the needs of these new engines, however. The higher proportion of soot often seen in the lubricant in these engines has direct implications for engine wear, as well as for the lubricant itself. As a result, Shell has developed unique “smart screener tests” in order to demonstrate wear testing and profilometry. These have enabled the analysts to screen oil for soot-related wear in particular. This is particularly useful if considering that the Cummins M11 wear test costs approximately US$100,000 per test.

Cummins M-11 EGR

API CI-4 Limits

Shell SAE 10W-40

Avg. Crosshead Wear (mg)

20 maximum

16.4

Oil Filter Pressure at 250 hrs. (kPa) 275 maximum

200

Engine Sludge Rating EOT

7.8 minimum

7.8

Top Ring Weight Loss (mg)

175 maximum

152.5

Table 1

Once this type of component-specific product testing is completed, all lubricant variants are put through their paces in engine bench testing. This phase makes use of fully automated test benches that run 24/7. Standardised engine cradles are utilised, allowing for quick engine changes when necessary.

Peak performance

While analysing oil’s performance and its effect on various components and the engine is critical, it is equally important to understand its behaviour in complete assemblies. This is why Shell has developed a unique driveline fuel economy testing rig situated at its R&D centre in Limits for Euro VI and US10 very similar Hamburg, Germany. It comprises a heavy-duty vehicle chassis, and includes a temperature controlled facility. Here use is made of the latest dynamometer technology, which uses a variety of transient test cycles and simulates real on-road operation, to evaluate the engine oil and gear (or axle) oil’s contribution to fuel economy. Only once the product’s performance in the driveline test-rig is acceptable, does field-testing commence. Here Shell draws on its extensive OEM partnerships around the globe to ensure that both on-highway and off-highway equipment is covered. In the case of the Rimula and Rotella brands, for instance, over 400 trucks were used to ensure all potential fuel and lubricant interactions were tested, and that these were fully understood.

HDDEO European trends

The latest range of European engines is being designed with a clear eye on the future, and meeting the requirements Two strategies to meet Euro IV and Euro V of Euro IV and Euro V legislation. As mentioned previously, working in isolation is no All lubricant variants are put through their paces in longer an option for forward-thinking OEMs. It engine bench testing has become a necessity to partner with lubricant manufacturers in order to effectively address the Presently, OEMs are focused on meeting the requirethree key issues of emissions, carbon dioxide and ments of Euro IV. That being said, while Euro IV fuel economy. limits have been set in European test cycles, engines THE SOUTH AFRICAN MECHANICAL ENGINEER

VOL 62

September 2012

OILS & LUBRICATION

when development began on these, which has had further implications. It also has to be noted that Euro VI will have limits on PM (particulate matter) count, as opposed to weight. These limits were only fixed at a very late stage. From a lubricant development point of view, it is important to note that the limits for Euro VI and US10 are very similar to one another. Taking this one step further, two key strategies have been adopted by OEMs (working in partnership with lubricant manufacturers) to meet Euro IV and Euro V. The first involves a combination of EGR (exhaust gas recirculation) and DPF (diesel particulate filters). Here the EGR will reduce NOx (nitrous oxide), while the DPF will capture soot particles. Alternately, OEMs can make use of selected catalytic reduction (SCR). In this instance, engine tuning will minimise particulate development, while SCR (with AdBlue) will reduce NOx.

Euro VI and US10 limits very close

The limits for the future Euro VI and US10 are very similar to one another will be homologated in a world harmonised cycle. In addition, conversion factors were not established

THE SOUTH AFRICAN MECHANICAL ENGINEER

VOL 62

Globalisation

In deciding how best to meet these requirements,

September 2012

OILS & LUBRICATION

OEMs are also considering the globalisation of the truck manufacturing market. We are already seeing the growing influence of the European Union on engines designed and manufactured in the USA. A number of Euro-designed engines are currently being built and sold across various continents including the Daimler world engine MB 4000 (designed in Stuttgart); the Paccar MX engine (designed by DAF Eindhoven); the Volvo world engine D13D (designed Required efficiency for SCR catalyst in GĂśteborg); and the Navistar MaxxComponents in the exhaust gas have the potential to Force engine (designed by MAN NĂźrnberg). As this globalisation continues to make itself felt in the market, many operators (especially those that own more than one brand of engine) are looking for a lubricant development partner that can perform on a global scale, as well as meet international requirements. As such, they need lubricants to increasingly resolve the fact that EU and US engine oil specs are growing towards each other. For example, the requirements of the Volvo VDS-4 are very similar to those of the Renault RLD-3, as well as the Mack EO-O Premium Plus. This can get quite complicated as the oil thus needs to meet API CJ-4 specifications, with tighter Mack limits, and the D12D test.

Very similar

As stated previously, the future Euro VI and US10 limits are very similar, especially regarding soot particles and NOx. Presently we are seeing that most OEMs typically use a combination of EGR, DPF and SCR to meet the US10 legislation. We can therefore expect OEMs to try to meet the requirements of Euro VI using similar hardware, but with a different balance between fuel and urea consumption. Considering the required efficiency for a SCR catalyst, the challenge relating to the corresponding high PM ratio are clear. Consequently, when it comes to after-treatment of exhaust gases that must meet the requirements of Euro VI, there are a number of significant implications:

harm the after-treatment system in use

X X by combining EGR, SCR and DPF, the EGR will ensure lower NOx, but will require a DPF with an oxidation catalyst (oxicat). X X The higher catalyst efficiency of SCR means that: i. tighter temperature control will be required (made possible through an oxicat and post-injection) ii. the NO2 vs NO ratio will be 1:1 (requiring an oxicat upstream) iii. higher urea conversion will make an hydrolysis catalyst necessary iv. there is a risk of ammonia slip (requiring an oxicat downstream) v. NOx sensors are needed to control and log NOx levels. Looking at a possible Euro VI layout, immediately reveals its potential sensitivity to the chemical composition of both the fuel and lubricant used.

Enhanced protection

It must also be noted how components in the exhaust gas have the potential to harm the after-treatment systems in use. Sulphur for example, can deactivate the oxidation catalyst, poison the SCR catalyst, and form sulphate particles which can block the DPF, while ash will block the DPF (as ash particles are not able to be regenerated). Magnesium can poison the NOx sensors, and Phosphorous can poison the catalysts (the oxicat and the SCR), as well as the NOx sensors.

THE SOUTH AFRICAN MECHANICAL ENGINEER

VOL 62

September 2012

OILS & LUBRICATION

Sensitive to chemicals from fuel and lubricant Possible Euro VI layout

Meeting the challenge

OEMs need to actively partner with lubricant manufacturers Because much of today’s diesel fuel is virtually sulphur-free, there needs to be a focus on low SAPS lubricants to address these challenges. Low SAPS engine oil specifications protect emissions systems by virtue of their composition. In the case of ACEA E6 oils, for example, these specs were formulated for European engines to ensure piston cleanliness, wear control and extended drain intervals, specifically. Also formulated for European engines, ACEA E9 oil specs were similarly designed (using the standard HDDEO requirements) to protect against deposits and sludge, as well as to enhance soot handling, and wear and oxidation control in particular. The API CJ-4 specs developed for US 2007-compliant engines can be seen to mirror ACEA requirements in many instances, demanding enhanced protection against soot-induced wear and oil thickening, and enhanced oxidation stability and sludge control.

In analysing how best low SAPS oils can be used to meet Euro VI requirements, it should be noted that SAPS-containing components play an essential role in terms of the engine oil’s actual performance: X X Metallic components that form (sulphated ash) during the combustion process are used in the detergent system, and provide anti-wear and anti-oxidising properties. X X Phosphorous is present in additive components that also prevent wear, and act as anti-oxidants as well. X X Sulphur is present in mineral base oils. It is required in the detergent system, and has antiwear and anti-oxidising properties too. With that in mind, Shell’s response to low SAPS requirements was to develop its Rimula R4 L and Rimula R5 LE low SAPS brands. These oils have since demonstrated a significant improvement in wear control when compared with conventional E7 and CI-4 Plus oils.

% Improvement for Rimula R4 L and R5 LE relative to API CI-4 Plus Engine test

Fuel type

Key parameter

R4 L

R5 LE

Cummins ISM

500 ppm S diesel

crosshead weight loss

Mack T-12

15 ppm S diesel

cylinder liner

Cummins ISB

15 ppm S diesel

tappet weight loss

OM 441LA

400 ppm diesel

bore polish roller

GM6.5L

50 ppm diesel

follower pin wear

Sequence IIIF

Gasoline

cam wear

Sequence IVA

Gasoline

cam wear

THE SOUTH AFRICAN MECHANICAL ENGINEER

VOL 62

Rimula R6 LME oil has similarly improved filter and catalyst durability, with SAPS levels clearly below the ACEA E6 specified requirement. This allows for filter cleaning intervals to be extended by over 100% when compared with (normal SAPS) ACEA E4 oils. The low oil consumption demonstrated in tests is a result of the oil’s very low volatility. While certain low SAPS oils can thus address some of the Euro

September 2012

OILS & LUBRICATION

VI challenges, the next key issue then becomes reducing fuel consumption and, with it, carbon dioxide emissions. This has to be done in the context of the ever increasing power of the latest generation heavy-duty trucks. Particular attention is also required regarding the friction created in these engines, with key areas being the piston assembly, valve train and bearings. Considering the manner in which a lubricant works (as illustrated by the Stribeck Curve alongside), the correlation between the friction coefficient and the oil film thickness can be seen. Also visible is the type of lubrication experienced at the piston rings, valve train, and engine bearings. All these factors are taken into consideration during product formulation. As new legislative and technology requirements continue driving developments within the transport sector, it is evident that OEMs need to actively partner with How does a lubricant work ? (The Stribeck Curve) lubricant manufacturers to find tenable solutions to new challenges. â&#x20AC;&#x153;In my opinion however, the value of these partnerships will ultimately be determined by the lubricant must have access to extensive analytical and testing manufacturerâ&#x20AC;&#x2122;s R&D capability. facilities. This will ensure that the lubricants they Not only must they demonstrate their formulat- develop are designed to not only meet challenges, ing ability and their extensive understanding and but also to meet future specification requirements. global experience in terms of field trial testing, but they must also be able to show their cost saving modelling and testing capabilities. To this end, they

Shell South Africa Energy, Henti Spangenberg, Tel: (011) 996 7000, Fax: (011) 996 7777, Customer line: 0800 027 027, www.shell.com

Bench engine fuel economy results

THE SOUTH AFRICAN MECHANICAL ENGINEER

VOL 62

September 2012

MILLS

Liners for Grinding Mills Spike Taylor, managing director of Multotec Rubber

Fitting replaceable liners in a grinding mill is not just a question of protecting the outer shell of the mill. The design of the liner and the materials used in its construction both play a critical role in the mill’s performance. By using the correct material and an appropriate lifter design, the mill will grind effectively. Conversely, the wrong choices can lead to poor grinding, excess energy usage and high liner maintenance costs.

“

SA Mechanical Engineer” visits Multotec Rubber, specialists in milling circuit solutions to talk to managing director, Spike Taylor, about mill liners. “In the small and medium size mills, rubber is steadily gaining ground as more cost-effective than steel liners,” he says. “We’re constantly working on improving the design as well combining different wear materials to achieve better performance in terms of mill liners.

Our focus is therefore more and more about identifying mill-related productivity issues in order to implement changes and improvements to liner design and achieve optimum performance and longer life “Mill linings, in rubber and rubber composite form, THE SOUTH AFRICAN MECHANICAL ENGINEER

“As our expertise lies in rubber linings, steel linings for extremely large diameter SAG mills are no longer supplied by us,” Spike explains. “Rubber liners work well in small diameter mills while rubber composite liners with embedded steel, like our heavy duty MultoMet liners have been specifically developed for large SAG mills up to about 6.5 metres in diameter.”

Productivity issues

Mill liners

make up a large percentage of our business,” he adds. “However, in terms of the mill circuit as a whole, we also do cyclones, trommel screens, the screening panels for vibrating screens, sampling plants and chute design, particularly chutes around the mill feeds.

VOL 62

In today’s tough economic climate, mill liners should

September 2012

MILLS

not be regarded as a commodity. Low cost liners could jeopardise production levels by hampering mill reliability. “Our focus is therefore more and more about identifying mill-related productivity issues in order to implement changes and improvements to liner design and achieve optimum performance and longer life,” Spike says. “A longer liner life not only reduces the re-line frequency, but also extends the period Lifter bars are trimmed to exact lengths of optimal grinding efficiency. “Although our core business does not include mill in less wear on the bearings of the mill but also liner handling equipment, we’re in a position to positively affects the power consumption of the advise customers on equipment that will reduce mill,” he adds. Being a resilient material, rubber is re-lining downtime, and increase re-lining safety,” user friendly, safer to handle and install. Its excelsays Spike. “To this end, we include attachment lent sealing properties reduce the risk of flushing systems into our liners that complement new or behind linings and eliminates leakage through existing liner handlers and we can custom design bolt-holes. Grate plates made of rubber are not as rigid as steel, this flexibility virtually eliminates any liners to suit specific equipment.” clogging in the grate plates, an issue which has a Monitoring wear direct influence on mill throughput. In terms of design, the company has made a significant investment by implementing a software The reduced weight of rubber not only results in less package which also costs its rubber and rubber wear on the bearings of the mill but also positively composite liners in accordance with best practice for mill liners. This is in line with the continual affects the power consumption of the mill drive to reduce costs. While rubber mill linings haven’t gone through any step-change improvements in design for many years, several alternative designs are available. Multotec exhibited six different liners with a variety of improvements and special features at Electra Mining Africa 2012 to enable discussions with mill users who are aiming to optimise mill efficiencies.

Advantages of rubber

Apart from the fact that rubber weighs less than steel, making it easier for relining purposes, it reduces the noise level of the mill significantly compared with steel liners. “Rubber has the ability to absorb energy because it has higher inner losses when exposed to dynamic strains,” explains Spike. “This means that the sound radiation from a rubber surface decreases considerably. A rubber thickness of 40mm, for example, reduces noise levels to the point where the use of earplugs is unnecessary. “The reduced weight of rubber not only results

Field services

“While our in-house installation teams provide a major benefit to customers, the rapidly changing schedules of mill shutdowns present a challenge in terms of deploying the correct manpower at the correct time,” Spike says. “Our new software has been developed to better monitor the liners in order to predict when a shutdown needs to take place so that our manpower can be better utilised.” In addition to using a computer simulation programme to provide the optimum liner configuration in terms of charge volume calculations to produce mill lining inspections and reports, installation teams supervise, assist or undertake complete lining installations. Spike says in conclusion, “Our field service maintenance teams carry out complete maintenance programmes involving the inspection and replacement of all our products used on a site.” Spike Taylor, Multotec Rubber, Tel: (011) 456-5734, Email: spiket@multotec.co.za

THE SOUTH AFRICAN MECHANICAL ENGINEER

VOL 62

September 2012

MILLS

Mills with a Difference

Ball mills can be modified to run more economically, not only in terms of energy consumption, but also as far as maintenance is concerned

There is no two ways about it, it takes a certain amount of energy to liberate minerals from rock and the best way has always been the grinding mill. Although the HPGR (high pressure grinding roller) which consumes less energy has its uses, for large capacity processing, the grinding mill is still the preferred method of efficiently liberating minerals.

Low speed solution

“A while back we installed the biggest volumetric SAG mill in the world at a gold mine in Ghana and soon after also supplied a 14 MW, 26 X 36 feet ball mill for the same plant,” Jeanne says. “This mine is now expanding significantly and the client basically wanted a duplication of the first ball mill for spares commonality.

Ricus van Reenen, sales manager at FLSmidth and Jeanne Ferreira, technology specialist in milling at FLSmidth

n addition, ball mills can be modified to run more economically, not only in terms of energy consumption, but also as far as maintenance is concerned. “SA Mechanical Engineer” speaks to the technology specialist in milling at FLSmidth,

A gearbox simply is a high risk factor in terms of picking up mechanical problems Jeanne Ferreira, about a new mill design they’re currently installing where the mill is driven by a variable speed drive, something not generally done on ball mills.

THE SOUTH AFRICAN MECHANICAL ENGINEER

VOL 62

“However, instead of a high speed drive train like the first ball mill, they wanted to reduce maintenance to a minimum in terms of mechanical equipment such as the gearbox required on a high speed mill,” he adds. “A design was finalised which is volumetrically the same size, but we increased the installed power to 15MW and opted, on the client's request, for a low speed synchronous solution with a VSD drive. Thus the girth gear, pinion arrangement is directly coupled to the low speed synchronous motor which is controlled by VSD.”

Advantages

Although this configuration comes at a cost, the advantages outweigh the expense. “At high power ratings like this, a gearbox simply is a high risk factor in terms of picking up mechanical problems,” Jeanne elaborates. “In addition to saving energy on start-up, beneficial features include anti-roll back, locked charge protection among others and you no longer need a mechanical barring-drive. A higher mechanical efficiency due to the elimination of a gearbox also reduces the absorbed power for a given duty. The capital cost increase from high speed

September 2012

MILLS

motor with gearbox to LSS motor can be justified by this saving on power. The payback time for the cost difference is just less than five years which makes this option an alternative worth considering.”

to their customers and often even having permanent maintenance teams on a mine which runs a lot of their equipment, this side of the business is rapidly changing.

A ball mill driven by VSD is not new to FLSmidth as several have been installed around the world in areas where production throughput is generally much higher than mines in Africa. “FLSmidth's first low speed synchronous ball mill installation managed by our American office, was on a platinum mine in Zimbabwe in 1996, making this current project a fairly new concept for African mining,” says Jeanne. “To this day we get feedback from this mine on the many advantages and the savings they’ve achieved by using this technology, in spite of the high initial costs.”

“We can consider establishing a satellite office in an area near these customers that has a large footprint of FLSmidth equipment so that service teams and the spares supply are close by,” explains Ricus. “As demand grows in a particular area, we can also consider building a new facility called a Supercentre, which includes a workshop and technicians to undertake pre-assembly and refurbishment work. This concept is being rolled out globally now in countries where we have strategic installations and a concentration of our equipment.

Options

The general trend in mining in Africa, however, is catching up with higher throughput on the agenda, resulting in many mines now upgrading or expanding and asking for bigger machinery and better efficiency performance. FLSmidth has always been a worldwide supplier of high pressure grinding rolls, but mainly for the cement industry. “Due to the success and effectiveness of this type of grinding machine and a growing demand for finer grinding and mine operators looking to reduce energy, we have invested in the development of high pressure grinding rolls technology for the minerals industries,” adds Ricus van Reenen, sales manager at FLSmidth.

Strategic installations

FLSmidth has always operated as a technology design house that employs various subcontractors to manufacture the equipment they design. However, by directly offering after sales service and spares

The general trend in mining in Africa, however, is catching up with higher throughput Supercentre

“Given the increase in local business and further up in Africa, we’ve now established a Supercentre in South Africa which is being built near Delmas as we speak,” says Ricus in conclusion. “This facility incorporates over 8 000 square metres of storage and workshop space fitted with heavy duty cranes to allow the stripping of large components for refurbishment. “By no means does it mean we’ll be manufacturing equipment ourselves, that will remain with the subcontractors we’ve worked with for many years, but we can now stock critical spares and service equipment in our own facility using technicians employed by us.” Jeanne Ferreira, FLSmidth, Tel: (010) 210-4000, Email: jeanne.ferreira@flsmidth.com

THE SOUTH AFRICAN MECHANICAL ENGINEER

VOL 62

September 2012

MARKET FORUM

Rubber Recycling

While oxygen enrichment is now commonly used in cement kilns which utilise recycled rubber as a fuel, Air Products’ burner system has evolved to a stage where its optimised design allows for complete process stabilisation and maximised output. The return on investment of an oxygen enrichment system is excellent. Companies adopting this methodology require an oxygen burner, an oxygen flow meter and NOx monitoring equipment, which monitors flue gases, to adequately decrease or increase oxygen flow. There are three different types of oxygen enrichment – low, medium and high – which vary the rate between 1 and 4 %. Documented benefits include an increase in clinker production of between 5 and 30%; an increase in usage of alternative fuels (such as rubber) of 30 to 80%; and improvements in kiln stability. Air Products, www.airproductsafrica.co.za

Sachin Kulkarni, Sales Manager of Bulk Gases

Hydrogen Sensing Instrumentation “As the long-standing agents for NEL hydrogen electrolyser plants, Pretoriabased Rand Technical Services (RTS) is often asked to provide the market with hydrogen monitors. Hydrogen electrolysers demand a purity level of better than 1% and existing in-line measurement technology are extremely bulky and difficult to operate, while reliable handheld versions simply did not exist,” says Ian Fraser, managing director of RTS. “The significance of our H2scan monitors is that they have been developed specifically for hydrogen Ian Fraser, managing director of RTS monitoring and are the only products on the market to provide a detection range of 15 ppm up to 100% detec- fast response times and its auto zero feature eliminates the need for frequent tion,” he adds. recalibration.” The H2scan handheld monitor is proving to be extremely popular in the market Ian Fraser, Rand Technical Services, Tel: (012) 933-9620, due to its portability. “Known as the Email: info@rtsafrica.co.za, HY-Alerta 500 handheld hydrogen www.rtsafrica.co.za leak detector, this product provides

THE SOUTH AFRICAN MECHANICAL ENGINEER

VOL 62

September 2012

Tooling Industry’s Growth And Development Key role players in South Africa's tooling, precision engineering, mould making, design and application development industry are looking to the annual AfriMold trade fair to play an important role in supporting, growing and developing their industry. The annual AfriMold trade fair takes place from 10 to 12 October 2012 at the Gallagher Convention Centre in Midrand. Stakeholders are unanimous in their support of the fair and believe it will give a boost to an industry that, like so many others in this economy, is experiencing slow growth and could use international exposure and input to enhance its competitiveness and relevance. Several industry players are also looking to AfriMold to support their initiatives to enter into Joint Ventures (JVs) and partnerships with foreign companies. Now in its 3rd year, AfriMold has established itself as the annual meeting place for Africa's industry leaders and pioneers. Ron MacLarty, organiser of AfriMold, explains: “The benefits of trade fairs like AfriMold are of course numerous, but perhaps the most important of these is networking. It's a rare opportunity to rub shoulders with manufacturers, agents, sales representatives, and everyone else involved in the industry. In industries like this, many of the big deals concluded come from meeting someone at a trade show, for the simple reason that people want to do business with people they have met.” Leigh Angelo Tel: (011) 869 9153; Cell: 082 954 7833; Email: leigh@tradeprojects.co.za www.afrimold.co.za

MARKET FORUM

Sorting Technology Breakthrough Sensor-based sorting company, CommodasUltrasort, has shown that its X-ray Transmission (XRT) sorting technology produces outstanding results in the separation of lumpy chrome ore. The most recent trials were conducted at a chrome mine in South Africa which is situated in the Bushveld Igneous Complex (BIC), the largest chrome and platinum source in the world. The CommodasUltrasort XRT chute

sorter has been operating on a full production plant at the mine processing 70 tons per hour at +90% availability. After blasting and trucking, the ROM is crushed and screened and the -60mm +20mm material reports to the CommodasUltrasort XRT sorter with the rest reporting to a conventional beneficiation plant. The feed grade into the XRT sorter averages approximately 32% chrome and the

process upgrades the saleable product to 36% or better at 97% efficiency. “We’re delighted with the results,” says a spokesperson for the mine. “Not only is the sorter performing beyond expectations it does so at a significantly reduced cost compared with more conventional dense media separation processes.” Lütke von Ketelhodt, CommodasUltrasort, Tel: 087 941-3840, Email: ketelhodt@commodas-ultrasort.com, www.commodas-ultrasort.com

Thruster Condition SKF has announced the availability of SKF Thruster Monitoring, an integrated and flexible condition-based maintenance (CBM) solution for propulsion and positioning thrusters (tunnel and azimuthing thrusters) in the marine and offshore industries.

The new monitoring solution is applicable for both ship operators and thruster manufacturers, and for aftermarket and new build installations. The SKF Thruster Monitoring solution can be used for all makes and types of thrusters across various sectors of the marine industry.

The SKF Thruster Monitoring solution combines all required information in one system, which can be integrated with both the thruster and ship management systems.

SKF Thruster Monitoring supports ship operators in achieving classification agency CBM requirements, as well as providing the basis for proactive maintenance and operational decisions based

on actual thruster condition. The marine industry continuously demands reduced dry-docking and higher availability of ships and the need for condition monitoring is increasing. SKF’s specialized thruster monitoring solution serves the entire marine industry value chain. Samantha Joubert, SKF South Africa, Tel: (011) 821-3500, Email: samantha.joubert@skf.com, www.skf.co.za

THE SOUTH AFRICAN MECHANICAL ENGINEER

VOL 62

September 2012

MARKET FORUM

Distilling Opportunities

Elgin Engineering’s Operations Manager, Julius Naidoo (in orange shirt) and Business Manager, Roger Haripersad on his right, with the team involved in the manufacture of the 38m distillation column

A 38 metre distillation column, designed and manufactured by Durban-based Elgin Engineering, was delivered to Sasol in Secunda on 17 August. With a diameter of 2.3 metres, this 316L stainless steel column is critical to solvent processing and was manufactured to unique Sasol specifications. The specialised unit, which will enable the constant production of solvents at the

Secunda plant, will be fully dressed with supplementary attachments installed by the Elgin Engineering team during the Sasol September shut down. “This is one of the largest columns built in KZN to date, and demonstrates without question that our province has the skills and capacity to produce quality engineering products at a significant scale,” comments Operations Manager,

Julius Naidoo. “The Elgin Engineering team’s goal is to bring more opportunities of this kind to Durban and KZN, and to continue to grow the skills and capacity of the entire supply chain.” Roger Haripersad, Elgin Engineering, Tel: (031) 274-0000, Email: enquiries@elgin.co.za, www.elgin.co.za

A New Record In 3D Printing Objet Ltd, a leader in 3D printing for rapid prototyping and additive manufacturing, has announced thirty-nine new 'digital materials' available with its Objet Connex range of multi-material 3D printing systems. Customers can now select from 107 materials ranging from rigid to rubber-like substances in terms of texture, standard to ABS-grade engineering plastic in terms of toughness, as well as from transparent to opaque, in terms of clarity and shades.

ties to closely resemble their intended end-product with the greatest level of realism. The use of the Objet Connex

multi-material 3D printer allows users to also combine up to fourteen of these materials; such as rigid and flexible, or opaque and transparent materials, at the same time in a single consistent model. DemaPlas Tech, Jacques Kleynhans, Tel: (011) 462-2990 Email: Jacques@ demaplastech.co.za

90 of the 107 materials made available by Objet are 'digital materials', derived by the composite mixing of primary Objet materials. This enables designers, engineers and manufacturers to simulate very precise material proper-

THE SOUTH AFRICAN MECHANICAL ENGINEER

Multi-Material 3D Printing is Better for your Product Design & Development

VOL 62

September 2012

MARKET FORUM

All in One “Nord drives, which consist of Unicase helical shaft mounting geared motors, have special features to meet the requirements imposed during water treatment procedures,” says Mark Barbour, divisional manager of BMG Drives. “These drives consist of gears, motors and brakes that are protected against corrosion. Special covers for the hollow shaft and motor also ensure that the drive is entirely resistant to spray from tanks and the humid and aggressive conditions to which it is exposed in sewage treatment plants.” Explosion proof motors, with electrical and mechanical speed control, are fitted with anti-condensation heaters for standstill periods and re-inforced bearings for extended life are standard. Special vent plugs, lubricants and a valve type oil drainage facility also enhance performance in these demanding applications. Drives with helical flange-mounting geared motors have the flexibility to fit into restricted and awkwardly shaped areas below tank de-sludgers. The travers-

ing platform of this system is equipped with a fourwheel drive to prevent wheels from slipping, even under load and in unfavourable wind conditions. A unique feature of these drives is the Unicase gearbox that accommodates all bearing seats within a rigid one piece casting - no bearing seats are located on bolt-on flanges or covers. Sealing

surfaces are not subjected to torque stress or overhung loads and hardended wheel bodies with specially treated teeth, ensure smooth and quiet operation at maximum load capacity. Mark Barbour, Bearing Man Group, Tel: (011) 620-1500, Email: markb@bmgworld.net, www.bmgworld.net

Flotation Plant Components Urethane Moulded Products (UMP) has completed a multi-million rand manufacture and supply contract for newgeneration flotation plant components.

were of a formulation standard for flotation plant. The order was executed in 120 days.

Trevor Carolin, Urethane Moulded Products, Tel: (011) 452-1000, Email: trevor@ump.co.za

UMP’s order comprised eleven flotation plant Dorr Oliver RS33 stator assemblies, thirteen large disperser assemblies (130m3), and 100 launders. Both the stator and the disperser are key components of the flotation tank. Launders channel froth into collectors for further processing. In recent years, UMP has augmented its expertise in manufacturing flotation plant components by developing an ability to undertake orders as turnkey projects. An ISO listing allows customers to ship internationally. For this particular order, UMP allocated a project management team to oversee design and manufacture of the moulds and inserts, recommend the polyurethane system, then cast and manufacture the complex components ahead of product assembly.

Disperser assembly designed and manufactured by UMP

The polyurethanes used in this project THE SOUTH AFRICAN MECHANICAL ENGINEER

VOL 62

September 2012

MARKET FORUM

Installation-Ready Pipe Joining

it further: they are delivered to the jobsite ready to install, without the requirement to first disassemble then reassemble a coupling on a joint. The coupling can simply be pushed onto the pipe ends as a single unit, and tightened with an impact wrench or standard hand tools. This speeds up installation, making pipe installation even more efficient.

Installation-ready couplings

Pre-assembled, compact and with no loose parts, Victaulic couplings work hard under pressure and are perfect for the HVAC market in South Africa Mechanical pipe joints – consisting of a coupling, gasket, nuts and bolts – offer considerable advantages over more traditional means of joining pipe while demonstrating equal or improved per-

formance under strain. The Style 107 is rated up to 5170kPa (750psi) and the Style 177 is rated up to 6900kPa (1000psi). Both couplings can withstand temperatures from -34°C to 121°C (-30°F to 250°F) depending on the choice of gasket. Installation-ready couplings improve on the original mechanical design by taking

In fact, Victaulic installation-ready couplings can be installed up to ten times faster than welding, six times faster than flanging, and twice as fast as standard mechanical grooved couplings. With fewer steps to install, the result is consistently faster pipe joints and reduced piping installation time, which allows contractors to optimise crew sizes and meet or beat project schedules. There is no need for hotworks and no loose parts that can be dropped or lost, so material handling is reduced as well as risk of injury. www.victaulic.com

Second Order

Based on excellent service, fast installation and product performance and quality from the initial installation, advanced nutrition company, Evox has installed a second order of Apex General Purpose Strip Curtains in its clean rooms to prevent cross contamination and ingress of dust into these hygiene-critical areas. Wim Dessing Senior, MD of Apex Strip Curtains, says that while manufacturing concerns frequently bemoan the ineffective control of dust and insect

ingress, coupled with variances in temperature, that result in hygiene, health and safety compliance problems, Apex Strip Curtains’ superior quality is gaining increasing attention in the marketplace as an affordable and viable solution for a spectrum of applications. “Apex Strip Curtains control six specific elements in a manufacturing environment: noise, temperature, hygiene, dust, insects, health and safety,” says Wim. “Our patented Balledge PVC strip

THE SOUTH AFRICAN MECHANICAL ENGINEER

VOL 62

curtains are equally at home in the food, pharmaceutical and heavy engineering industries as effective control mechanisms against various foreign elements. They are transparent, allowing unimpaired visibility that eliminates accidental collisions between pedestrians and vehicles, while at the same time ensuring durability and longevity from the specially-formulated PVC.” Wim Dessing, Apex Strip Curtains, Tel: (011) 452-8723, www.apexstrip.co.za

September 2012

MARKET FORUM Both Cavex clusters include the supply of Isogate valves with Linatex rubber linings. This order was swiftly followed by a second contract from the Kwale Mineral Sands Project calling for the supply of 55 pumps including tailings pumps, cyclone feed pumps, plant and sump pumps — one of the largest orders across the product range that Weir Minerals Africa has received out of East Africa. “Both products are field proven in the harsh mineral sands arena throughout the world which gives An illustration of a cluster of 14 Cavex CVX 500 cyclones our customer added confidence in the combination,” Weir Minerals Africa’s cyclones and engineered systems product manager, JD Singleton, says.

Substantial Order

Weir Minerals Africa has received a substantial order for the supply of its cyclones to Base Resources’ flagship project, the Kwale Mineral Sands Project in Kenya. Not only is this one of the company’s biggest orders to date in Africa for the supply of Cavex cyclones, but it is also the first time that it will supply Linatex rubber liners in the Cavex technology.

“This is a global first for us, offering the customer the best of both worlds — the superior metallurgical efficiency that Cavex cyclones can deliver, combined with the formidable performance of Linatex liners.” Rene Calitz, Weir Minerals Africa, Tel: (011) 929-2622, Email: r.calitz@weirminerals.com, www.weirminerals.com

From From the the Outside Outside

Compact and Efficient Goscor KLG has introduced a new series of air compressors: the Sullair S-energy 3000, 3700 and 4500. These 30, 37 and 45 kilowatt models are designed for point-of-use facility installations. According to Goscor KLG national sales manager Kevin Miller, Sullair designed the 3700 Series compressors to answer end users’ and maintenance workers’ demand for a product that is more compact, cost and energy efficient, serviceable and powerful – and yet quieter – than available 30, 37 and 45 kilowatt compressors. All standard compressor maintenance can be performed from one side of the machine and the compressor’s fluid level can be checked without opening the doors. The series also features a fully-sealed environmental protection pan to capture spills that may occur during servicing. The new compressors use less energy than equivalent models. Based on 24/7 operation, using full load specific power at 64c per kW/hr, the 3700 offers 11,3% energy savings over competitive 37 kW models. Additionally, oil carryover in the 3700 Series is less than 1 ppm, which is less than half the carryover of similar compressors. Goscor KLG, Kevin Miller, Tel: 0861 GOSCOR (467 267) www.goscor.co.za

The new Metso Megaliner shell liner keeps downtime in large mills to a minimum, utilising an innovative design that offers speedy replacement. It also improves worker safety during maintenance, as the liners are bolted into position from the outside of the mill, so workers do not need to stand in the ‘drop-zone’ of the liners. Mill availability is improved through faster liner replacement. Megaliner uses larger

than average liners, yet these can still be placed with the same 6- to 8-axis liner handlers used with many large AG mills. Using larger liners means mills require fewer of them and Megaliner also has fewer attachment points compared with conventional liners, speeding up installation even further. Liners are easily and accurately positioned before bolting with the aid of highly visible, coloured guiding markers.

The system makes removal and replacement of liners just as quick, safe and easy as installation. Bolting and unbolting is straightforward as the threaded portion of the standard hex-head liner bolts is protected from dust, corrosion and general mechanical damage. Once loosened, it is often possible to remove the liner bolts simply by hand-turning them. Pneumatic or recoilless hydraulic hammers are not needed to dislodge worn Megaliners, as gravity alone is generally sufficient. Metso, Tel: (011) 961-4000, Email: mineral.info@metso.com www.metso.com

THE SOUTH AFRICAN MECHANICAL ENGINEER

VOL 62

September 2012

MARKET FORUM

Hydraulics and Machinery

On the Move

Alex Gerazounis

KDP Services, established in 1989, specialises in the design and manufacture of hydraulic power packs, installation of pipe lines, servicing and repairing of all hydraulic equipment, and hoses and fittings. The company supplies all control valves (proportional, screw-in, flow control, etc), filters, field service and fault analysis, as well as, test facilities. They undertake the design and manufacture of cylinders, medium and high pressure pumps, plus motors. On the CNC machining front, KDP specialises in the following fields: heavy

David Main

Mark Koerner Mark Koerner has been appointed as Philips Lighting General Manager and Solar Africa for southern Africa.

mining and industrial components (pivot bolts, shearing bolts, shafts, bushes, bearing caps, pins, couplings, chain rollers, conveyer pins); hydraulic components (shafts, pistons, adaptors, glands, connectors, manifold blocks); toolmaking components (cavity plates, punch plates, die sets, core pins and cores), and draughting (CAD design, drawings, and assemblies). KDP Hydraulic Services & Engineering, Tel: (011) 392-5774, Email: kdpservices@acesurfer.co.za, www.kdpservices.edx.co.za

Hendrik Marais

Ruan Le Roux

Hansen Industrial Transmissions has announced the following new appointments to their Jet Park head office in Boksburg: David Main – Sales Manager: Key Accounts, Hendrik Marais - Engineer, and Ruan Le Roux – Sales Engineer.

AMEC has made the appointment of Alex Gerazounis as its Johannesburg office’s new commercial manager.

Billy Rodrigues Billy Rodrigues has recently been appointed as the Managing Director of the Mozambique and Malawi regions and will be running Bridge Shipping Group’s new facility in Beira, Mozambique.

Yasas Jayakody Johnson Controls Global WorkPlace Solutions recently appointed Yasas Jayakody to their team as its South African Project Operations Manager.

Index to Advertisers AESSeal

23 - 26

Horne SA

Afrimold 22

Loesche 39

Artic Driers

M&J Engineering

Contact Mark Bennett on Tel: (011) 781-1401,

Multi-Alloys 21

or E-mail:

Multotec 30

samecheng@promech.co.za

Chemserve 10

PPS 15

to book your

Compressed Air

SAEE 21

advertising space

Atlas Copco

Outside Front Cover, 8

Associated Energy Services

Engen 32 Eskom

ILS

Inside Front Cover

Outside Back Cover

THE SOUTH AFRICAN MECHANICAL ENGINEER

VOL 62

September 2012

BULK HANDLING IN AFRICA Dear Client, Africa is on the brink of an economic takeoff. The question is not whether you should do business in Africa, but rather how/ when/ how much? “Bulk Handling Today” (BHT) will be publishing a new “BHT in AFRICA GUIDE” which will focus on the track record of South African companies working in Africa. “BHT in Africa” will feature comprehensive information on companies working in Africa from EPCM/turnkey to small bearing suppliers, for example. We’ve conducted research on the distribution of the guide and have identified the following sectors:

Distribution (printed copies) - 5502 Mining Houses (in SA, SADC, Africa and overseas. eg, Anglo, Exxaro, Rio Tinto, Vale) Chamber of Mines Mining departments (local and in Africa) Trade Commissions in Africa Project Management companies GAMA Members (African members of the Consulting Engineers of SA) Procurement/buying departments In addition “BHT in Africa” will be mailed out with the Nov/Dec issue of “Bulk Handling Today” and given out from our stand at Mining Indaba 2013 in February 2013.

Distribution (electronic) - 2376 An exact replica of the magazine will also be emailed to a well-researched list of mine managers and mining engineers at all African mines. “Bulk Handling Today” has purchased an updated list of email addresses of Buyers, Engineering Managers, Mine Managers, and SHE Managers working in mines/for mining houses throughout Africa. In addition, “BHT in Africa” will be available from our website: www.promech.co.za for a year. Be sure to be part of this launch issue of “BHT in Africa” by means of advertising your company and educating readers throughout Africa on your products and services.

Rates 4 Pages (1 Advert, 1 Page Advertorial and 2 pages Q & A) 3 Pages (1 Advert and 2 pages Q & A) 2 Pages (2 Pages Q & A) 1 Page ½ Page ¼ Page All rates exclude VAT.

R39 500 R36 000 R26 000 R15 000 R12 000 R 7 400

Make sure you’re in this comprehensive reference publication! Kind regards Surita Marx Sales & Marketing

“Bulk Handling Today” covers the movement of all bulk goods from Point A to Point B. We concentrate on the equipment used to undertake this task such as shipping, railways, cranes, trucks, conveyors etc. Another important aspect is logistics, freight forwarding, customs etc. It is the only magazine which covers this topic exclusively.

l Tel: 011 781-1401 l Fax: 011 781-1403 l Cell 083 281 5761 l bulkhandling@promech.co.za l l www.promech.co.za l THE SOUTH AFRICAN MECHANICAL VOL 62 BULKENGINEER HANDLING TODAY

September 2012 February 2012

471

MOHLALENG_ESKD_562/ ENG/Demand Response

The Demand Response

Rewards Programme makes

business

sense.

The Demand Response Rewards Programme offers a financial incentive for businesses to shift their electricity use. Itâ&#x20AC;&#x2122;s a programme designed to reward consumers for not using their electricity load at a period of high demand. What are you waiting for? This programme is rapidly gaining ground among commercial and industrial users of electricity as a way of reducing load and improving their bottom line. To join the programme visit www.eskom.co.za/idm or call 08600 37566.

Eskom Holdings SOC Limited Reg No 2002/015527/06

THE SOUTH AFRICAN MECHANICAL ENGINEER

VOL 62

September 2012