SHAPA Newsletter April 2019

Mar/Apr 2019

NEWS

Level Sensors Selection Page 6

Dust control food processing Page 10

SAFETY AND COMPLIANCE

NFPA DUST HAZARD ANALYIS Page 11

Introduction

By Ian Birkinshaw, General Secretary - Solids Handling & Processing Association

Continuous Improvement Without change there is no innovation, creativity, or incentive for improvement. Those who initiate change will have a better opportunity to manage the change that is inevitable is a quote from William Pollard. While the quote is more than two hundred years old, it still rings true in our ever-changing world. The pace of change is pushing forward ever faster with advancements in technology moving at a pace never seen before in our history. Against the backdrop of international trade wars, the uncertainty of our future relationship with the EU, the need to keep improving is essential.

The Solids Handling industry as a whole is continually moving forward with these changes as part of a continuous improvement process. While some of the improvements over the last year have seen a step change in the capabilities of some SHAPA Companies as was ably demonstrated in the shortlist for the 2018 Solids Handling Industry Innovation Award, some of the improvements are not as evident. That’s not to say these improvements are not important they are vital to the success of the member companies and the industry at large, at a time when there are many challenges to overcome, continually moving forward is the best way to keep ahead. This is where being a member of SHAPA helps. From its very beginning in 1981 the Solids Handling and Processing Association has existed to produce and disseminate high quality relevant technical, commercial, legal and marketing intelligence in a lively and engaging manner.

A little look at last year’s programme of events demonstrates this ambition of living, learning and continual improvement. Earlier in the year the 10th Annual SHAPA Digital Marketing Workshop was presented in association with Susan Hallam the internationally acknowledged expert in this ever-changing environment, who recently was awarded an MBE for her work in this area. The subjects included 10 new features in Google, 10 ways to improve your website visibility, 10 ways to use social media, 10 new ways to communicate with your customers and prospects and 10 things to change on your website before GDPR hits. As usual the event was attended by a wide range of members from SME,s through to large multi-nationals. Due to the enthusiasm by the SHAPA Membership 2 | SHAPA Newsletter

for this workshop another workshop has been organised and booked for the 27th March at the Hilton East Midlands Airport Hotel, this years topics agreed by the SHAPA marketing committee include Content Marketing and Strategy update, B2B social media, Forms on website (good or bad), Voice search and E- privacy law. Visit www.shapa. co.uk for further details.

Introduction to Bulk Handling Building on the back of previous successful engineering the future workshops which focused on young engineers entering the industry this year SHAPA held its first Introduction to Bulk Handling workshop which was a joint production from both SHAPA technical and marketing committees. The workshop focused not only on young engineers but also colleagues in the support sectors such as marketing, spares, finance, etc. and new entrants to the industry who had little or no knowledge of the full end to end processes involved in a solids and bulk handling project.

This workshop was held at the Nestle facility in York and a big thank you goes to Nestle for helping SHAPA run the event. In order to ensure a greater understanding of the processes

involved the workshop used the analogy of an industrial bakery with a domestic kitchen in the production of a fruit cake. Following an introduction by the host and the committees the workshop started with a shopping analogy which investigated recipes and warehousing and was then followed by Ingredients, characterisation and safety considerations; Storage; Conveying, discharging and feeding; Quantity and measurement; Sieving, blending and mixing; Time, temperature and monitoring; Presentation and packing and finally the workshop finished with Distribution and traceability. The whole of the workshop was recorded so that it could be made into a series of u-tube clips and webinars in the future. Due to the success of this venture more workshops are to be held in the future with details posted on the SHAPA website at www.shapa.co.uk Total cost of ownership was a main focus in 2018 but will again be in 2019 this is a very important consideration for all SHAPA members, their clients and the industry at large. It is well known that the capital cost of plant is only part of the overall purchase cost and all wise engineering purchasers will probe operating costs, planned maintenance and repair costs, set against the costs of unplanned downtime. Total life span and depreciation are obviously part of the mix too. All of this has been addressed by the SHAPA Committees and a new paper has been produced to give assistance to suppliers and purchasers in navigating the process to ensure that the installed plant operates in line with the overall expectations. Information on this paper has been uploaded to the SHAPA website and can be downloaded here

Introduction for Business, Energy & Industrial Strategy ( BEIS ) in formulating a plan to minimise the difficulties for post Brexit trading with the EU and the rest of the world irrespective of the deal or no deal discussions, which at the time of writing are dominating parliament and the media with its twists and turns. With only a few weeks left until we officially leave the EU on the 29th March, industry is now craving for certainty over the final decision so that effective plans can be made to ensure the continued success of manufacturing and the solids handling industry as a whole.

In order to bring some clarity to the situation following Brexit, SHAPA is holding a series of workshops the first is in June on Safety of Machinery - CE Marking for machinery Training Course. The objective of this course is to give designers of machinery the knowledge and tools to design safe machinery in accordance with European Union Machinery, and associated Directives, and to look at any divergence due to the UK leaving the EU and it effects on compliance. The course is internationally recognized Level 3 program of study and is designed to benefit the practical requirements of machine designers, engineers & managers.

2019 Solids Handling Industry Awards Following the success of previous awards highlighting the successes in the solids handling industry community, SHAPA has launched the 2019 Solids Handling Industry awards, these awards are once again open to all UK registered member and non-member companies and institutions operating in the Solids Handling and Processing Industry. Application forms are available direct from the SHAPA website at Shapa-Awards-Application-Form and the winners will be announced and presented at the awards ceremony at the Royal Armouries Museum on the evening of 8th May 2019. Once again, this year the Solids Handling Industry Awards fall into four categories with a closing date for applications on the 28/02/2019.

The award categories are Export Award, The

Innovation Award, Newcomer of the Year and Company of the year Award.

In October last year SHAPA in conjunction with the IMeche bulk handling committee awarded Alan Jackson the prestigious 2018 IMeche Bulk Solids Handling Award for services to the bulk handling Industry at the recent Bulkex conference.

Collective expertise Clearly no single person, company or even a trade association can be expert at everything, which is why in these turbulent times, Shapa along with 13 other trade associations in the Engineering and Machinery Alliance ( EAMA) have been working with government departments especially the Department of International Trade ( DIT ) and the Department

Commitment to the future SHAPA may well have celebrated nearly 40 years’ valuable service to our industry, but it is not resting on its laurels and is looking to the future and how best to develop the solids handling community going forward whether its training, networking, celebrating success or wishing to influence government on vital subjects including international trade.

Therefore, any company involved in the supply of solids handling equipment and services should consider Joining SHAPA, today’s membership stands at well over 100 companies, who have already tapped into the benefits of membership. Vitally, however, companies, consultants and suppliers involved with new solids handling projects or in the process of updating existing process plant should first consult the equipment finder and technical papers on the SHAPA website – just a click or two away at www.shapa.co.uk, or email info@ shapa.co.uk.

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Consultancy and Short courses for the Process Industry: Bulk solids handling technology

We support industries that are seeking to resolve process problems, develop design schemes for plant expansion, or simply improve product quality.

Consultancy services

Some of our Consultancy services include advising on: Storage and Discharge of bulk materials Pneumatic Conveying of bulk solids Spoiling of materials in storage and in transit Plant and Equipment design/redesign Ship Unloading/ quayside operations Control of plant wear Dust control Bulk Materials characterisation ATEX/DSEAR compliance Expert Witness services

• • • • • • • • • •

Short courses for Industry

We also provide a range of short courses to help delegates identify potential bulk materials handling problems and advise on how to avoid and/or overcome these issues.They fall under 4 main categories Pneumatic conveying:

storage of bulk materials:

•Pneumatic Conveying of Bulk Materials • Pneumatic Conveying System Design • Rotary Valves; Design, Selection and Operational Issues • Commissioning and Troubleshooting ‘Hand’s On’ Pneumatic Conveying Systems

general bulk materials handling:

• Storage and Discharge of Powders and Bulk Solids • Design of Equipment for Storing and Handling Bulk Materials • Biomass Handling, Feeding and Storage (can be adapted to

other materials such as waste, recycled goods, pellets)

sPecialist areas of concern:

•Overview of Particulate Handling Technology • Dust Explosions - How to demonstrate DSEAR/ATEX Compliance • Port and Terminal Operations for Bulk Cargoes Measurement of the Properties and Bulk Behaviour of Particulate Materials • Introduction to Processing Dry Solid Materials

• Caking and Lump Formation in Powders and Bulk Solids • Undesired De-blending and Separation in Processes and Equipment • Electrostatics in Powder Handling • Numerical Modelling of Solids Handling and Processing • Dust Control in Processes Powder Handling and Flow for Additive Manufacturing

bulksolids.com

Boone Mixers

FBall mixer side view

Cementing a great mix for F Ball -Energy saving mixing in a green factory John R Boone supplied an energy efficient Horizontal Delta Blade mixer to cementitious product manufacturer F Ball Ltd for high speed mixing with low power consumption, achieving a high throughput with a very short mixing cycle. The highly efficient process comprises weigh hoppers that feed the JR Boone mixer, discharging via a‘bomb’ door to an under hopper that feeds a packaging and palletisation line beneath; a process that requires good control and a short mixing cycle to achievethe total batch time of under two minutes for a 2 ton mix.

The history of F Ball, the UK’s leading producer of flooring adhesives, leveling products and grouts, goes back 125 years, originating as an ink manufacturer, moving from London to Staffordshire during the second world war and into a purpose built factory on an eight acre site in 1989. It was in the early 1990’s that they installed their first mixer from John R Boone Limited and so began a relationship that has continued and developed, leading to their latest purchase of a Boone Horizontal Delta Blade

Mixer for high speed production in their new powder mixing plant.

The new plant is designed to produce up to 30tonnes of blended material per hour. At any time there may be as many as six batches within the process: one in each of the two weigh hoppers containing the bulk materials (sand, cement) together with additives such as flow promoters and set retarders; a further batch in the mixer, mixed material in the under hopper and two further batches within the packing and palletisation line. With that amount of work in process, mixing speed and efficiency is paramount, thoroughly blending the additives throughout the bulk materials before the bomb door opens and the mixed material is deposited into the under hopper.

A key objective for the plant was that it would have as small an environmental impact as possible, and a vital part of that objective was to minimise the energy used, for example by the use of gravity fed rather than mechanically

conveyed processes and making every element of the process as energy efficient as it could be, including the mixer itself. F Ball approached JR Boone for a solution, JR Boone proposing their Delta Blade technology.

The Delta Blade is a plough type mixer, with a precisely engineered blade shape that uses the principles of high agitator speeds to radially and axially accelerate the product formulation in a short crisscross pattern within the mixer shell.

Higher levels of shear are produced with lower power consumption than more conventional mixers, meaning that batches are mixed quickly, thoroughly and homogenously using minimum energy, reducing the carbon footprint of the new installation.

F Ball naturally wanted to confirm all this, soJohn R Boone provided a test mixer on site so that the efficiency of the Delta Blade mixer could be thoroughly tested with F Ball’s materials, checking that they could achieve the batch times that they needed.

Since entering service a further benefit of the Delta Blade system has been noted due to its highly efficient mixing actionand despite the abrasive nature of the materials in use, no wear parts have been replaced in over two year’s operation.

As Steve Tubby, F Ball’s Operations Director, put it: “Our experience of Boone’s since we installed the Rotary Drum Mixers back in 1991 has always been very positive, we have been able to rely on their support whenever we have needed it.

The Delta Blade mixer was exactly what we were looking for, a fast, energy-efficient solution that gave a consistently high quality mix in the shortest time possible. Boone’s engineers were extremely responsive throughout the project and clearly understood what we were trying to achieve.”

For more information contact JR Boone on: 01260 272894 sales@jrboone.com www.jrboone.com F Ball mixer with cage

SHAPA Newsletter | 5

Feature

By Lana Erickson, BinMaster Digital Marketing Manager

The Why and How of Choosing Level Sensors to Fit Your Process Needs Level indicators have been around for decades. From simple switches and rotaries, to advanced non-contact sensors, there’s no shortage of technology to choose from. But what role do level sensors actually play in today’s manufacturing operations, and how do you choose the best fit for your needs?

Sensors Save Time – and People Whether your operation is large or small, at one central location or spread across geographically dispersed sites, utilising utilising level control sensors can maximise efficiency by automating cumbersome – and often dangerous – manual tasks. Simple, yet effective, point level sensors can serve as high, mid-, or low-level indicators.

Fail-safe models help control processes and warn of overfills, outages, or equipment failure.

Continuous level sensors such as the versatile 80 GHz non-contact radar are not only accurate, even in extremely dusty or noisy environments, they can integrate with LAN or cloud-based inventory management programs to make it easy to access, manage, and report on inventory any time, from anywhere.

Streamlining data in this way cuts down on time spent on cumbersome spreadsheets, optimises inventory turnover, and—with permissionbased user roles—makes it simple for everyone from the plant floor to accounting to access and work from the same information without wasting time on communication confusion.

Sensors Prevent Problems Overfilling vessels ruins materials, wastes time, makes a mess, and causes unnecessary down time. Utilising level controls streamlines material monitoring and process control.

Automated alerts prevent overflows, empty conditions, clogged chutes, and jammed conveyors. For a long life and maximum ROI, choose a sensor that is designed for your operation’s environment. High temperature

models or non-stick coatings ensure the long life of equipment with minimal maintenance.

In applications where material piles unevenly, 3D level sensors can be used to circumvent issues caused by bridging or silo wall buildup.

By using advanced acoustics-based technology and multiple-point measurements, this type of sensor can display a three-dimensional representation of inventory level as well as calculate volume. This both eliminates concerns about accurate inventory and helps pinpoint vessel stress areas where uneven loading may impact the life of a silo.

Making the Choice Today’s manufacturing operations are increasingly automated with more sophisticated and complex systems. Plus, with increased consolidation, multinational corporations, and a global economy, the needs of the industry have changed. The market for level indicators has responded with new solutions to address those demands, creating flexible options and integrative software to allow manufacturers to customise their solutions to achieve their best fit for inventory level monitoring.

The most crucial part to choosing a level control sensor or system to meet your needs is understanding the options available.

Data management programs keep operations efficient, allowing users to access inventory information remotely and receive customised alerts.

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Point Level Indicators As the name implies, point level indicators alert when the level in a silo reaches a certain point. For timely replenishment or process control, a point level indicator uses a relay to send an alert to a control room, horn, light, or an alarm panel when material reaches or falls away from the device. They can be used for high, mid, or low-level alerts in a wide variety

Feature of dry bulk solids including granules, pellets, and many powders.

It is very common for point level indicators, such as rotaries, capacitance probes, vibrating rods, diaphragm switches or tilt switches, to be wired to a horn or light to indicate a full or empty status. This happens most frequently when the level indicator is used to start or stop a process to prevent running out of an

understanding the radio frequency range of the device and its potential impact on other equipment in the plant is an important consideration.

• Vibrating Rod: The vibrating level sensor is a piezoelectric-driven, vibration-type level switch that can be used for level detection in bins, silos, and hoppers filled with powders and other dry bulk solid materials.

15°. A fixed-mount tilt switch mounts from the outside on the top of the silo though a process connection. It is custom-made to a specific length determined by the distance from the top of the silo an alert should be activated. Alternatively, a hanging tilt switch is installed by suspending it from a flexible cable within the silo or over a pile of material or a conveyor. A hanging tilt switch also can be used for plugged chute detection. A note of caution: some tilt switches are made using mercury, so be sure to select a mercury-free model if one is required for compliance with environmental regulations.

Continuous Level Sensors Integrating continuous level sensors allows an operation to monitor how much is in one or all silos in real time or at scheduled intervals.

Cable-based sensors, non-contact acousticsbased, open-air radar, or laser level sensors are commonly used in large storage silos. Open-air radar and laser are also appropriate for narrow silos. Guided wave radar is ideal for smaller silos containing solids or liquids.

• Bob or cable-based sensors: A cablebased or bob-style sensor works like an automated tape measure but eliminates the need for climbing silos to take manual readings. It reliably, accurately, and repeatedly takes measurements at predetermined time intervals or on demand.

Data can integrate with LAN or cloudbased software for monitoring and alerting when pre-determined high- or low-level thresholds are encountered.

Flexibility is a key attribute of point level sensors. While commonly used for high level indication, they can trigger an alarm anywhere along the vessel wall—alerting for inventory status and timely refills.

ingredient or wastefully overfilling a silo.

Common point level indicators include: • Rotary: The familiar workhorse of the manufacturing world, rotaries have a continually rotating paddle. When the paddle meets resistance due to the presence of material, it stops rotating and sends an alert. Conversely—as a low-level indicator—rotaries can be set to alert when the material drops below the level of the paddle and it resumes rotation. Rotaries can be customised with a variety of paddle types, extensions, and mounting options and are available in fail-safe models, making them ideal for continuous processes as well as an inexpensive backup option for other monitoring systems.

• Capacitance Probe: Capacitance sensors operate by detecting the presence or absence of material in contact with the customisable probe by sensing minute changes (as low as 0.5 picofarad) in capacitance caused by the difference in the dielectric constant of the material versus the air. Capacitance probes can easily be configured for a wide range of applications.

When selecting a capacitance probe,

The rods of these rugged sensors are often constructed of durable stainless steel and are almost wear and maintenance-free. A vibrating level sensor can be mounted on the side of the vessel when used as a high-, mid-, or low-level alert. Alternatively, they can be used for high-level, top-mounted applications when built with a rigid or flexible extension.

• Diaphragm Switch: A diaphragm switch, also called a pressure switch, is a very basic, affordable level sensor commonly used as a high-level alert on a silo wall. It can be mounted internally or externally. Internal mounting doesn’t require a hole to be cut in the vessel wall. An external mount has the advantage of mounting from the outside via a hole cut in the wall, so there is no need to get into the silo for installation. There are models for non-hazardous locations or with explosion proof certifications. Pressure switches are also used for plugged chute detection.

• Tilt Switch: Tilt switches are designed to install easily and require no routine maintenance. They serve as a high-level indicator, activating an alert when material rises and tilts the switching mechanism

80 GHz non-contact (open-air) radar is an ideal solution for precise targeting to avoid obstacle interference.

• Open-air radar: Open-air radar, also referred to as non-contact radar, transmits a radio‐frequency signal to the material surface, reflecting a small portion of the signal back to the sensor’s antenna. The sensor processes this returned signal to determine the material’s level. Sensor models are available with different antenna types and operating frequencies (typically ranging from 6 GHz to 80 GHz). Which model will perform successfully in an application depends on the vessel height, the material being measured, the presence or absence of dust, and the sensor’s Continued >> SHAPA Newsletter | 7

Feature operating frequency. An 80 GHz radar measures in a very focused 4° beam angle that is ideal for precise targeting and works well in tall, narrow vessels and in silos that need precise targeting to avoid obstacle interference.

• 3D scanners: 3D level scanners use dust-penetrating acoustic technology to provide very precise volume accuracy. They can measure and map the material surface to detect irregular material surfaces, cone up/down conditions, or sidewall buildup.

A 3D scanner is unique because it can map the topography of the silo and create a computerised profile of its contents. They are proven to perform in high-dust environments where some other types of non-contact technologies struggle to perform reliably. Multiple 3D scanners can be combined to measure the entire surface of large diameter silos as well as domes.

Specialised software can enable viewing of all silos across an entire location or organisation.

Capanivo ® Compact & flexible

Clever capacitance level detection of liquids, pastes, foam & interface measurement Use in non-metallic containers possible!

CN 7000 The pocket-sized one

• Laser: A laser level measurement sensor is used for level control, plugged chute detection, and monitoring buildup. It is a non-contact device that can be used in bulk solids, pellets, or granular materials of all material dielectrics in a variety of vessels. The advantage of laser is it measures in a tight beam, making it suitable for use in very narrow vessels or constrained spaces. Laser can be pointed at an outlet to ensure timely replenishment of material or mounted near the sidewall to detect buildup. Laser is ideal in low or no-dust environments.

Some battery-powered models are available, making them useful in situations where wiring may be difficult.

• Guided wave radar: A guided wave radar is a sensor that suspends a cable down into the silo to measure liquids, powders and bulk solids with a dielectric constant greater than 2.1 in vessels up to 78’ tall. It utilises time domain reflectometry (TDR) to measure the distance, level and volume of material.

The sensor is immune to dust, humidity, temperature, pressure, and bulk density changes as well as noise present when filling or emptying the vessel. Guided wave is often used for smaller vessels containing ingredients or additives. It is a good complement to other types of continuous level sensors in a network.

Conclusion Utilising level control sensors will save time, reduce risks, and improve the overall efficiency of your operation. A wide variety of sensors, accessories, and sensor configurations are available. The ROI of your sensor choice will depend greatly on your operation’s size and type, the number and size of vessels you use to store materials, and the type of materials being stored. Additional considerations include how often you need to measure your material levels, who needs access to the data and how it will be shared, and – of course – your budget. Most sensor suppliers offer an online application worksheet addressing many of these questions to help evaluate your application. Completing the worksheet is great preparation for working with a supplier to select the right continuous level sensor for your needs. Custom systems using a variety of sensors and software are easily configured working directly with a level sensor specialist.

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Compact design Enclosure version or integral cable version Synthetic version available Chemical resistance Optional PVDF probe SensGuard protective sleeve 2-wire instrument y” itivit Sens “Tip hnology Tec

CN 8000 The allrounder Pipe and cable extension Range of process connections High safety standard Hygiene versions Very high sensitivity Digital version with LCD

UWT (UK) Ltd • 01743 718883 •

sales@uwtuk.com www.uwtuk.com

The effective way to suppress and stop explosions Solutions for chemically suppressing and isolating explosions by BS&B Safety Systems feature a modular design and do away with pyrotechnic triggers. This makes installation, repair and transport easier.

Dust explosions in industrial facilities can be devastating due to the extreme rise in pressure. IPD, the system for suppressing and isolating dust explosions from BS&B Safety Systems, detects critical rises in pressure to the millibar and reacts at lightning speed. The highly effective extinguishing agent smothers any flame in an accumulating explosion in a fraction of a second, long before the explosive pressure is unleashed. When used for isolation, the IPD system stops the explosion spreading to connected parts of the facility. This provides effective protection to people, machinery and the environment.

Modular design means easy onsite resetting To make sure the IPD system is ready for use again quickly after being triggered, the designers at BS&B developed a new, modular design. This allows for immediate resetting on site, reducing production downtime to a minimum. Unlike other solutions, the owner or operator can reset the system independently after triggering.

The extinguishing unit consists of an unpressurized, easily replaceable extinguishing agent cartridge and a pressurised container that’s filled with nitrogen during installation or reset. The lack of a pyrotechnic trigger means that none of the individual components or the completed system are classified as hazardous goods. This makes both handling and spare parts logistics and management much easier. It also shortens delivery times and reduces cost of ownership, as there is no need to comply with the obligatory safety regulations for transport that apply to conventional systems.

Furthermore, the extinguishing unit requires no extra discharge nozzle for the agent. Instead, the integrated rupture disc becomes an aerodynamic outlet when activated. The design avoids the use of plumbing that can become blocked.

Alongside the extinguishing unit, the explosion suppression and isolation system features a control unit with touchpad and the patented Triplex sensor. This ensures constant, real-time monitoring of the process pressure, allowing for fast and reliable activation. Three highly sensitive pressure sensors are arranged in a way that maximizes sensitivity while avoiding activation from vibrations. In the event of

Metal Detection Services are delighted to announce that their in house training room is now officially open!

MDS have created a bespoke space within their headquarters, near Manchester, where they can provide dedicated training courses within a controlled environment. Having this space allows for a “hands on” approach with training, ensuring that each trainee receives the best instruction available.

Courses can be provided on a half or full day package with all the materials included. Each session will include the basic principles of a metal detector, retail codes of practise and common basic faults. Bespoke training is available where necessary. This is an ideal opportunity for new starters, and to continue developing existing staff knowledge as new codes of practise are introduced.

There are a number of working metal detectors in house which allows training to be held on

a metal detector with certain access to equipment, which can be difficult in a busy factory.

All MDS Engineers are highly experienced with several brands of metal detectors.

Andy Elder, the MDS Field Service Supervisor says “We’re really excited to have this facility, it’s a great space to do training as it’s away from the distractions and noise of the factory floor. We can also guarantee access to a metal detector, which is often difficult when we do training on-site”.

To find out more about this facility or to book a session you can get in touch with MDS on 0161 286 0870, or book online through the MDS website

a power cut, the internal battery continues operation for at least eight hours. This provides enough reaction time to establish a secure energy supply.

Protection for dusty production environments The IPD explosion suppression and isolation systems are used in all production environments where flammable dust is created or powdered substances are stored, handled and processed. Examples include the chemical or pharmaceutical industries, as well as the production of foods, feed and engineered woods. By responding to the incipient stage of a dust explosion, the IPD System reduces the pressure developed by the combustion event to a safe low level, as low as 0.2 bar. This is the combined result of having a low nitrogen gas pressure to disperse the extinguishing agent and the use of sodium bicarbonate as a fast heat absorbing agent.

For more information, please visit www.bsbsystems.com.

Posi-flate Exhibiting Inflatable Seated Buttterfly Valve in Operation in Stand #2-326 at Powtech Posi-flate manufactures a complete line of inflatable-seated butterfly valves for handling a wide variety of dry bulk granular solids, liquids and gases.

Posi-flate will be exhibiting a heavy duty inflatable seated butterfly valve operating next to a typical resilient seated valve at the upcoming Powtech Show in April to demonstrate how quickly a resilient seated valve can wear in comparison to the air operated Posi-flate valve.

The inflatable seat design provides a better seal by utilising air pressure to expand the seat against the disc, providing more sealing area and an even pressure distribution against the disc every time.

Tork-Mate Extended Life Actuators

Also on display will be Posi-flate’s line of Tork-Mate extended life pneumatic actuators. The Tork-Mate 890 Series actuators achieve up to 15 million cycles maintenance-free, at low cost.

They are ideal for 90° and 180° turn devices such as butterfly valves, ball valves, plug valves and damper valves. They meet the latest NAMUR standards, allowing direct or close coupling of NAMUR designed accessories.

For further information contact Posi-flate, on: +44 1908 622366 sales@posiflate.co.uk www.posiflate.com

Posi-flate Series 585 Butterfly Valve

SHAPA Newsletter | 9

New ‘business wins’ help dust control specialist boost sales by 40% news is that this is just the start and there’s significant potential for us to increase market share considerably both in the UK and overseas.”

Dustcheck, which holds the ISO9001 quality accreditation, provides tailored solutions for all dust control and containment requirements through clever, innovative design, manufacture and installation.

A string of new contract wins helped a leading manufacturer of dust control and dust extraction systems secure a record year.

Dustcheck Ltd, which was established in 1978, has seen sales rise by 40% over the last twelve months - including exciting projects to help Weetabix, Marley Eternit and Johnson Matthey ensure their workspaces are dust free.

Significant investment in the sales engineering team and improved customer support and aftermarket care has been behind the firm’s strong growth and plans are

already in place to build on this with the development of a new product range.

“This was a real milestone moment in the 40-year history of our business and has given us access to the resources and expertise of the wider group, such as working with MultiFan Systems on larger projects that need a single-source solution.”

“We’ve only been in the Group for a short while and sales have already increased 40%...the good

of Glasgow-based Dust Control Solutions and this gave us a real foothold in Scotland and a base for Filtermist’s service and Local Exhaust Ventilation (LEV) engineers based north of the border.

“That’s one area we’re really looking to grow. The other main focus will be on the food industry, where we are launching a dedicated marketing campaign to highlight the benefits of a dust free environment to companies in this sector.”

“We have enjoyed sustained expansion since the company was acquired by Filtermist International Ltd in 2017 to become part of the globally successful Absolent Group,” explained Andy Darby, UK Sales Manager at Dustcheck.

He continued: “Customers are really liking this approach as we can now complete projects quicker and take care of additional responsibilities they were going elsewhere for.

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The company supplies a leading range of cartridge, bag and panel filtration products to customers spanning more than 10 different sectors, including food, pharma, construction and plastics and rubber.

Its design team works with clients from the outset to specify the right technology to ensure a dust free workplace, which avoids costly equipment breakdowns, reduces energy usage, improves processes and prevents catastrophic events, such as explosions.

He concluded: “This is particularly relevant to the bakery sector and comes off the back of a new Health and Safety Executive (HSE) commitment to address occupational lung disease in the workplace, an issue that is estimated to cause 14,000 cases every year and results in 400,000 lost working days.

“We can provide solutions that help meet legislation and, importantly, ensure the best possible working environment for your staff.”

Importantly, the bespoke and standard systems will create a healthy and safe working environment for staff.

Andy went on to add: “In May last year, we acquired the business assets

For further information, please visit www.dustcheck.com or follow @dustcheckltd on twitter.

Feature

By Jeremiah Wann, President and CEO of Imperial Systems Inc

SAFETY AND COMPLIANCE:

NFPA DUST HAZARD ANALYIS Since the earliest days when people began to store and handle grain in bulk quantities, fires and explosions have been a hazard. Almost any organic material is combustible as a dust, and this includes almost all food products. The National Fire Protection Association (NFPA) has issued standards for handling combustible dust in general, and for handling food and agricultural dust specifically. The industry has made great improvements in raising awareness and improving safety procedures, and the NFPA has led the way in setting standards for combustible dust handling and fire prevention.

COMBUSTIBLE DUST HAZARDS Most food industry dust is combustible. The National Fire Protection Association (NFPA) has several standards that relate to the food processing industry and to combustible dust. Food processing materials that can cause fires or explosions include flour, sugar, spices, powdered drink mixes including coffee and tea, whey powder and powdered milk, dust from shelling or processing nuts, and corn or rice starch. While the Occupational Safety and Health Administration (OSHA) has dust control standards that relate specifically to certain types of agricultural dust, there is no general combustible dust regulation for all industries or materials.

The food processing industry has a history of combustible dust incidents, including the well-known Imperial Sugar explosion in 2008.

Sugar dust had accumulated throughout the facility, and when ignition occurred in a storage building and adjacent silos, the explosion caused numerous other explosions throughout the facility. The secondary explosions, caused by accumulated dust disturbed by the blast, caused even more

damage. 14 people died and 40 were injured. OSHA fined the company over $8 million dollars, noting that the owners should have been aware of the hazards in the facility, including accumulated dust and lack of employee training. The company also settled over 40 lawsuits from injured employees and families.

To prevent these kinds of devastating combustible dust incidents, NFPA 61, the Standard for the Prevention of Fires and Dust Explosions in Agricultural and Food Processing Facilities, addresses the specifics of fires and explosions in this industry. More recently, NFPA 652, the Standard on the Fundamentals of Combustible Dust, has introduced new recommendations that apply across all industries that handle combustible dust. NFPA 61, along with other industryspecific standards, are now being adjusted to align as closely as possible with NFPA 652.

NFPA 652 AND DUST HAZARD ANALYSIS As of September 2020, all facilities with dust present are required to have performed a dust hazard analysis. This must be documented, Continued >> SHAPA Newsletter | 11

Feature

and during an inspection OSHA can request this document and verify it.

This process starts with an analysis of the dust itself, but it also involves inspecting all equipment and areas of the facility for potential hazards and documenting the plans to address them.

Dust can be collected and sent to a testing facility. The test results will establish whether the dust is combustible and other information, such as the force it can exert in an explosion and the temperature needed to ignite it.

When companies are installing a dust collection system, this type of dust test may be requested to help the company decide what types of fire and explosion safety features to install on the system.

NFPA 652 details the areas of a facility that require a dust hazard analysis, and what to look for.

Any area where combustible dust is transported, accidentally or as part of the manufacturing process, must be examined. This also includes ductwork or other ways that a fire could travel from one process area to another.

Fugitive dust that escapes into other parts of the building, even hidden or unnoticed areas, must be identified. Dust explosions have occurred when dust accumulated unnoticed in spaces such as above drop ceilings or inside access spaces.

For every area or process identified as a potential dust hazard, the potential for fire or

explosion must be assessed. If there is oxygen and an ignition source available in the presence of combustible dust, there is a risk of fire. If these two factors exist and the dust is also suspended in the air, or could become suspended in air, conditions exist for a deflagration or explosion.

Once these hazards are identified, they must be documented, and a plan for addressing the hazard must be put into place.

One very important strategy is basic housekeeping, which means cleaning up all fugitive dust immediately before it can start to build up. Since many food processing facilities require a high level of hygiene anyway, housekeeping is likely to be part of the regular process.

However, some areas can be overlooked, and some processes generate so much dust that basic housekeeping measures will not keep it under control.

Some types of industries use water to keep dust from igniting and to keep it from becoming airborne. This many not be an option in the food processing industry, since the combustible material may be a process ingredient that needs

12 | SHAPA Newsletter

to stay dry. Using compressed air to blow away accumulated dust is not an acceptable method of removal, since causing dust to become airborne creates a higher explosion risk.

Dust collection systems are a recommended strategy for controlling combustible dust. In the food process industry, there are multiple options for types of dust collection systems, but all of them will need to meet the same basic safety standards laid out by NFPA 652 for this type of equipment.

DUST COLLECTION SYSTEMS FOR DUST MANAGEMENT The best way to control the accumulation of fugitive dust in the food processing facility is to install a dust collection system. There are many options for these types of systems, but considering the combustibility of food production dust, all will require NFPA recommended safety features.

While the number of fires and explosions in the food processing and agricultural industries have remained steady for many years, the number of injuries and fatalities has decreased considerably. In part, this is due to safer dust collection systems. In many recent situations, a fire has

Feature been confined to the dust collector and not able to spread back into the building.

Baghouses are a popular option in many areas of food processing.

These dust collectors filter out dust using long cloth bags. The bags may be kept clean by a fan or by compressed air pulsing.

Baghouses are efficient for most materials, but not for extremely small dust particles. They also tend to be very large, because many bags are needed to create enough surface area for filtration.

Baghouses continue to be very popular in the food processing and agricultural industries, especially where the dust is not extremely fine. Although bags are very durable, removing and replacing them can be a very messy and time-consuming task.

Another option for dust collection systems is a cartridge collector.

These use pleated cartridges that are kept clean with pulses of compressed air. The cartridges have a much higher surface area than bags, so the dust collector can be smaller. Another advantage of the cartridge collectors is that the filters are much easier to remove and replace than bags in a baghouse. Cartridge collectors can also achieve a higher level of filtration for very small particles.

NFPA 652 recommends several fire and explosion safety features with a dust collection system.

First, the airflow in the system

must be high enough to keep all dust moving through the system and not accumulating in the ductwork. This means that it is not safe to make modifications to the system without checking to make sure the airflow isn’t compromised.

All types of dust collectors need to have appropriate explosion venting that will direct the force of an explosion in a safe direction and prevent dangerous pressure inside the collector. If standard explosion venting through panels can’t be achieved because the collector is located inside a building, the system will require either a flameless explosion vent or a chemical suppression system.

An explosion isolation valve is a safety device that is mechanically triggered by the force of an explosion. When it closes, it prevents the explosion and fire from traveling any farther.

Spark traps and abort gates are both designed to prevent fires from occurring in the dust collector. A spark trap is a passive prevention device that extinguishes sparks before they can reach the collector. An abort gate is attached to a sensor that registers the presence of flame or sparks. The sensor will cause the abort gate to slam closed and safely vent the hazard. Chemical extinguisher systems are also available. When triggered, they use chemicals to rapidly extinguish a fire.

DESIGN OF DUST COLLECTION SYSTEMS Dust collection systems for food processing are usually source capture systems, which means they will have a hood located at the point where dust needs to be collected. The most typical setup is one or more dust collectors with ductwork leading to the hoods and fans large enough to maintain airflow to all the capture points.

Occasionally, some part of the process may be in an area that’s difficult to access with ductwork or so far away from the system that maintaining airflow is a problem. In this situation, a small cartridge dust collector can be placed directly at the capture point. These small and compact systems can be located on conveyors and other food process equipment. The only requirement is that they have access to power for running the fan and compressed air for pulse cleaning.

The most important aspect of a dust collection system is that it does not allow any significant amount of dust to escape or accumulate in the facility. A dust hazard analysis will help identify all the possible locations where dust needs to be controlled.

It should also be noted that a dust collection system will not address dust that has already accumulated in the facility. Cleaning up dust accumulation should follow NFPA 652 recommendations, which means avoiding any method

that causes the dust to become airborne. Vacuum systems can be used if they meet NFPA standards.

ACHIEVING SAFETY AND COMPLIANCE The NFPA standards are always geared toward preventing damage, injury, and loss of life. Compliance with their standards will create a safer work environment. Because the food processing industry makes up a large percentage of overall combustible dust accidents, following these standards is especially important.

Improved safety features have helped prevent accumulation of dust in food processing facilities.

They have also improved the ability to control potential explosions and contain them safely within the dust collector. However, fugitive dust that escapes during the process can still accumulate and ignite if problems in the dust collections system aren’t addressed.

A dust hazard analysis will help identify any dust problems that exist before putting in a new dust collection system, or problems with the current system. Addressing these problems as soon as possible helps keep dust under control in the facility, greatly reducing the risk of a fire or explosion. By making the dust hazard analysis a thorough, documented process, companies will be able to present safety inspectors with evidence that they are proactive in handling dust control.

SHAPA Newsletter | 13

World-Leading Trade Fair for Processing, Analysis, and Handling of Powder and Bulk Solids

EXPERIENCE THE DYNAMIC ENERGY, SHARE KNOWLEDGE, OPTIMISE PROCESSES First comes the experience, then the success: discover the entire spectrum and dynamic energy of mechanical process engineering. POWTECH is the trade fair event for bulk solids – and the place where process optimisation begins.

9-11.4.2019 NUREMBERG, GERMANY Honorary sponsors

Together with

PT19_225x155_GB_Process_Industry_Informer_ALLG.indd 1

Dynamic Air Exhibiting Operating Pneumatic Conveying System, Bella Mixer and Vibratory Equipment at Powtech Stand #2-319

Dynamic Air, a world leader in the design and manufacturing of pneumatic conveying systems and process equipment, will be exhibiting an operating pneumatic conveying system as well as the Bella twin shaft mixer and vibratory equipment, at the upcoming Powtech show in April.

Dynamic Air has developed 16 different pneumatic conveying concepts, utilising both pressure and vacuum, for handling a wide variety of dry bulk solids to provide a conveying solution that fits the process perfectly.

A fully operational dense phase pneumatic conveying system will be on display along with the Bella XN double-shafted mixer in 304 stainless steel food grade design.

The Bella twin shaft paddle mixer achieves fast, high-capacity, low shear, precision mixing of either dry bulk solids or liquids with solids. Regardless of particle size, shape or density, materials are mixed with a fast, efficient, and gentle action with typical mixing times of 15 to 30 seconds.

14 | SHAPA Newsletter

Professional knowledge right from the experts and contacts that will help you move ahead: The supporting programme will make your trade fair visit even more worthwhile with the following highlights: • Expert Forums for Chemistry and Food • Pharma.Manufacturing.Excellence. Forum • Networking Campus • Special display area for explosion protection • VDMA Special Show: Dust knows no borders

GYRO EX Bin Activating Feeder and Discharger

Also on display will be Dynamic Air’s line of vibratory equipment including the Stedi-Flo vibratory pan feeder and the GYRO EX bin activating feeder and discharger which produces a controlled gyratory motion to positively withdraw granular materials from bins, storage silos and hoppers at any desired feed rate for a consistent and reliable discharge.

For further information contact Dynamic Air Ltd, on: +44 1908 622344 sales@dynamicair.co.uk www.dynamicair.com

19.12.18 10:31

CHEMICAL POWDERS DE-LUMPED WITH BULK BAG CONDITIONER

Scissor lift raises the bulk bag to a preselected height while hydraulic rams with contoured end plates press opposite sides of the bag to loosen solidified powders.

DSM Coating Resins Spain S.L. is the world’s largest producer of polyester resins and one of the largest producers of specialty emulsions. To produce saturated polyester resin powders used in protective coatings for bridges, ships and automobiles, DSM receives large volumes of dicarboxylic acid and diol ingredients in bulk bags.

Both materials agglomerate during shipment and storage, preventing them from flowing out of the bulk bag, which required operators to break lumps using hand tools. To eliminate the cost, mess, delays, and safety concerns of manual methods, the company installed a Block-Buster® Bulk Bag Conditioner that de-lumps the materials automatically.

Workers originally emptied the bag onto a grate in a caged area and proceeded to crush the lumps using hand tools. “These manual methods created significant time loss and disturbances in the loading

Hydraulic rams fitted with specially contoured end plates press opposite sides of the bag to loosen solidified powders.

The turntable and bag rotate 90º to condition all sides, while the scissor lift allows conditioning at all heights.

process while posing risk of injury and discomfort to workers,” says Elio Sanchez, Project Manager at DSM Coating Resins Spain. And DSM still encountered blockages in the downstream process, further slowing production.

Bulk Bag Conditioner breaks up caked chemicals efficiently, safely Manufactured by Flexicon (Europe) Ltd., the Bulk Bag Conditioner is installed in a safe atmospheric area near the front end of the process, which feeds the factory’s blending reactors.

Housed in a free-standing support frame, the unit measures 2210 mm high by 3378 mm wide by 1981 mm deep. It is equipped with two hydraulic rams fitted with specially contoured end plates, and a powered scissor lift with variableheight turntable.

Forklift loads a bulk bag into the conditioner.

Once a forklift loads a bulk bag onto the conditioner’s platform, the operator closes the safety interlocked doors.

From the unit’s control panel, the operator programs the ram pressure, number of ram cycles, single or multiple turntable heights and degree of rotation, according to the dimensions of the bag and the conditioning required to loosen the material throughout the bag.

After pressing “start,” the conditioning cycle is automatic: the bulk bag is raised hydraulically to the pre-selected height, the end plates press opposite sides of the bag to break down the agglomerates, and the bag and turntable rotate 90° to condition the adjacent sides. The unit can also be programmed to automatically repeat conditioning cycles at multiple bag heights.

The material now flows freely from bulk bag spouts into reactors, where

1 to 3 tonne batches are converted into saturated polyester resins.

Mr. Sanchez says the Bulk Bag Conditioner has cut the time to de-lump materials by 75 percent and improved the quality of raw materials entering the factory’s reactors while improving safety.

Since dicarboxylic acid is a main ingredient in most batches produced, the conditioner is in use daily.

Flexicon (Europe) Ltd. 182 John Wilson Business Park Harvey Drive Whitstable, Kent CT5 3RB +44 1227 374710 sales@flexicon.co.uk www.flexicon.co.uk Flexicon (Europe) Ltd. Sicilia 253, 4°, 1a 08025 Barcelona, SPAIN Tel: +34 647 670 302 ventas@flexicon.es www.flexicon.es

SHAPA Newsletter | 15

Feature

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Speak to an expert today, call 01782 599454 or visit www.dustcheck.com Engineering a better environment 16 | SHAPA Newsletter

Fit for Liquids Under the banner “Fit for Liquids“ UWT is proud to launch a brand new product series in the field of liquids measurement. The new capacitance measuring sensors for continuous and point level detection offers new options for the UK and international market.

With the new UWT liquid level detection range, pin-point accuracy and total reliability, UWT offers continuous and point level detection in liquids, pastes, foam and slurry as well as interface measurement.

The UWT sensors work with the combination of the capacitive measuring principal and the change in frequency of the sensor which has a far greater switching accuracy than just the capacitance when the probes are submersed in liquid. This allows the probe to also maintain its high accuracy when it comes to viscous media like syrup or honey as the sticky build up on the probe does not affect the switching output signal. This ensures the best possible dry run detection of any system.

Another further advantage is the ability to measure interface between liquids – water and oil, foam and beer – with high repeatability and accuracy. All devices are equipped with potted electronics and work with the unique “Inverse Frequency Shift” technology. They provide a robust, certified construction and offer suitable solutions for a wide variety of liquids, pastes and foams – whether to be used for aggressive chemical applications, within the demanding food industry or in wastewater handling. Through a variety of metal rope, cable, rod and pipe extensions the units can be easily adjusted to single conditions of the process vessel.

Thanks to the integrated “Tip Sensitivity” technology the Capanivo® range with the CN 7 and CN 8 level detectors guarantees high reliability for products that cause caking. The Capanivo 7000 delivers a very compact design for limited space, available as enclosure or integral cable version as well as synthetic model.

The Capanivo® 8000 on the other hand is a universally applicable all-round talent due to its range of process connections, hygienic versions and the high safety standard.

For further information contact UWT on: 01743 718883 sales@uwtuk.com www.uwtuk.com

UWT has expanded the RF limit switch line with the robust Rfnivo® 8000 that includes a hightemperature version for a wide temperature range from -40°C to +400°C and pressure resistance up to 35bar. The PFA isolation ensures high degree of chemical resistance.

The NivoCapa® 8000 measures the continuous level in conductive and non-conductive materials with complete accuracy. At the same time the LCD display with control buttons and diagnostic function make the level sensor very userfriendly. The integrated “Active Shield“ technology found in the RF and NC devices ensures precise measuring results even when detecting media that tend to stick to the probe.

SHAPA Newsletter | 17

PROTECT YOUR DUST FILTER AGAINST FIRE AND EXPLOSION

Firefly’s unique Spark Detection System is based on true IR spark detectors that are insensitive to daylight.

They are designed to detect all dangerous ignition sources, such as hot dark particles, sparks and flames within milliseconds.

Baghouse performance monitoring for reduced operating costs For optimum performance, fabric filter baghouses require correct and timely maintenance.

ENVEA’s UK business (formerly PCME) manufacture a range of particulate monitoring systems, from simple leak to QAL1 certified measurement instruments providing Process Operators with an improved understanding of their baghouse operation.

Designed to monitor dust releases from single or multiple filter compartment baghouses, sensors installed in the clean gas output of each filter chamber are able to detect leaks as they develop, even down at very low emission concentrations.

Knowing where leaks are developing enables process stoppages and maintenance times to be scheduled saving time and resources by highlighting which bags require changing prior to potential emission limit excursions.

In addition, ENVEA now provide sensors to warn of hopper blockages, often a

18 | SHAPA Newsletter

cause of bag filter abrasion and which can potentially result in explosions within the filter. For Combustion applications which require sorbent injection such as lime or activated carbon, PicoFlow sensors are available to measure the quantity of injected sorbent. Ensuring the correct amount is injected maintains acidic conditions in the filter at the desired level preventing costly damage to the baghouse and also helps to prevent sorbent over usage and consequent wastage.

For further details of ENVEA’s range of Particulate Emission and Solids Flow instrumentation, contact: +44 (0)1480 468200 contact.gb@envea.global www.enveauk.global

More information at: www.orthos.co.uk Call us: 01858 464246 For enquiries: sales@orthos.co.uk

GERICKE GMS Batch Mixers: New sizes, new options Based on sound scientific knowledge, extensive trials and the experience from many installations around the globe, the double shaft mixer GMS Mixer is the technological leading mixer on the market. With new options and functionalities the GMS is the optimal process solution for many applications. The batch mixer is now available in sizes from 140 litres up to 5’000 liters.

Highest homogeneity Short mixing time while maintaining high mixing efficiency. Homogenous mixing of microingredients (down to <0.001%) has never been easier and faster and effectively substitutes the need of expensive premixes The effectiveness of the mixing (RSD <1.0%) can easily be checked in one of Gericke’s test centers around the globe.

Liquid injections The design of the GMS mixer and the high mixing dynamics with the fluidised zone do not only allow for mixing of powders but also

for the efficient addition of liquid ingredients.

Efficient delumping and dispersion The new optional cutters (patent pending) can be added in the front door to disperse agglomerates.

With its large diameter and optimal location in the mixer process chamber it works highly efficiently. For cleaning the front door swivels open, thus the cutter is highly accessible for cleaning.

With this new feature the GMS becomes even more flexible to meet additional process requirements.

Heat transfer The GMS also comes with inflated double shell housing, which allows to control the temperature and safeguard the product quality. The active cooling or heating is achieved by the means of efficient heat transfer from the jacket to the mixer. Typical application for controlled heat transfer are mixing of synthetic products that are sensitive to high temperatures and the addition of liquids that tend to crystalise on the cold mixer housing.

How Various Types of Screening Motion Can Impact Performance In simple terms, screening is the mechanical process of separating dry bulk materials based on particle size. Material is fed into a screener, which utilises precision-woven screens configured to sort the material according to the desired size, as required for the application.

Screener manufacturers employ different screening motions to accomplish the separation, and the screener’s motion significantly affects the efficiency of the separation.

This paper will provide a brief overview of mechanical screening applications before exploring the different types of screening motion and their various levels of efficiency and efficacy.

Types of screening applications Screening applications are typically broken into three categories: Oversize removal: The process of removing particles that are bigger than what is desired in the final product. Oversize particles are typically 5% or less of the incoming feed material’s particle-size distribution. Consider a product like fertiliser. To achieve a desired distribution of particle sizes, oversize removal is performed prior to shipment, isolating and removing unwanted clumps that, in addition to negatively impacting the aesthetic appeal of the final product, could interfere with the delivery of the intended nutrient concentration and potentially clog the spreader.

Fines removal: The process of removing particles that are smaller than desired. In this application, fine particles make up 10% or less of the particle-size distribution of the incoming feed material. Consider a cat litter product derived from bentonite clay. To ensure the final product does not include unacceptably small granules that could stick to a cat’s paw, the manufacturer could perform fines removal before packaging.

Of course, many applications require both oversize and fines to be removed, which can be achieved in a two-deck screener. In this

case, the final product is usually defined with an upper and lower size specification, with a small allowance for particles outside the size specification.

some screeners operating as high as 3,600 rpm.

Short-stroke machines typically have a higher frequency, while long-stroke machines tend to operate at a lower frequency.

Product grading: The process of separating an incoming feed of material into several different product grades. Consider sugar, which could be broken into a coarser grade (to be sold as granulated table sugar), a finer grade (to be sold as confectioner’s sugar), and a superfine grade (to be sold as baker’s sugar). Grading is typically performed in one multiple-deck machine. It is more challenging than simply performing oversize or fines removal, because it involves meeting several different size specifications and handling a greater volume of particles that are of a similar size to the separation opening (near-size).

Slope: This refers to the angle of the screen deck relative to horizontal. Some screeners use screen decks that are at or near horizontal, while others can have the screen decks inclined as much as 35 degrees. If a short-stroke screener is being used to process a high volume of material, it will typically have a higher degree of incline, in order to move the material rapidly through the machine.

Motion Function The motion of a mechanical screener serves three main functions throughout the separation process. The screener must spread and convey material from the inlet to the outlet; it must stratify the material, with the smaller particles migrating through the bed depth of material toward the screen opening and the larger particles moving upward, thereby producing a graduation of particle size; and it must separate the material as particles are presented to the screen opening.

Additionally, it is important to ensure the screen openings stay open and don’t blind, or become blocked. The screener’s motion typically enables a method for controlling blinding, often by implementing mesh cleaning balls or slider rings under the screen clothing to flex or scour the screen wire and dislodge any particles that have blocked the openings.

Motion terminology The motion employed by a particular mechanical screener can be broken down into three parameters: Stroke: This is the amplitude of displacement that the screener moves during its operation.

Typical strokes range from 1/8 inch (3 mm) up to 3 ½ inches (90 mm) of displacement.

Frequency: This refers to the number of cycles per minute the device moves.

Frequency tends to range from 200 rpm on the low end up to 1,800 rpm on the high end, with

Stroke, frequency, and slope combine to influence the behavior of the particles on the screening surface. When considering how efficiently and effectively a mechanical screener will convey, stratify, and separate the material being processed, it is useful to examine its stroke, frequency, and slope. For example, consider the potential impact of slope. A near-horizontal screen deck will provide more accurate separation, because the openings that the particles encounter as they reach the screen deck are almost the exact same size as the openings in the screen wire itself. Conversely, a screen deck that is inclined at, say, a 20-degree angle will provide projected openings to the particle that are smaller than the actual openings in the screen.

Types of motion These typically fall into three categories: Vibratory motion: By definition, “vibratory” means moving rapidly to and fro, or up and down. So, these machines are associated with a short-stroke, high-frequency motion and typically incorporate both horizontal and vertical components to their motion.

Gyratory motion: The screen deck moves in a circular fashion, as observed when the screener is seen from a plan view perspective. This motion is typically associated with a longerstroke and lower-frequency screener.

Gyratory reciprocating: In machines that utilise gyratory reciprocating motion, the motion is gyratory at the feed end and is converted to reciprocating action at the discharge end. An elliptical shape to the motion occurs in the middle of the machine, as the motion transitions from gyratory to reciprocating. Like gyratory machines, gyratory reciprocating machines are typically associated with a longer-stroke and lower-frequency.

How does motion affect performance?

It’s important to consider the various differences between screening motions when selecting the right equipment for a

SHAPA Newsletter | 19

particular application. For example, the vertical component of vibratory motion can be suited to disrupting surface tension in wet applications or working with a material that has surface moisture. However, vibratory machines tend to be less effective in more challenging dry product-grading applications, because the vertical component of their motion – which is necessary for conveying the material – tends to hinder the stratification process. When particles are launched from the screen deck by that vertical component of the motion, they are being remixed rather than being stratified.

In addition, these particles are being denied contact with the screen opening while launched, further reducing efficiency.

Gyratory motion is very effective at quickly spreading the material across the width of the screen deck and achieving a consistent bed depth of material. The horizontal nature of the gyratory motion is also effective at stratifying the material, with the smaller particles moving toward the bottom of the material bed depth and the larger particles moving toward the top, thus facilitating the separation process.

degree of mesh cleaning ball movement than those that use a shorter stroke. Another factor to consider: Longer-stroke machines can move material over a certain distance at a lower speed than shorter-stroke machines, enabling them to handle the product more gently. Finally, gyratory and gyratory reciprocating machines can process a relatively high volume of material at near-horizontal because of their longer strokes, whereas shorter-stroke vibratory machines typically must be inclined for high-capacity applications.

To best understand how a screener’s motion affects the separation performance in a given application, it is useful to review the product recovery efficiency for the defined size range of the material. The product recovery efficiency is defined as the amount of on-size product The reciprocating action of the gyratory that is recovered divided by the amount of reciprocating screeners excels at separating on-size product in the feed that could be near-size particles, thereby boosting the recovered. This important measurement should screener’s separation performance. As this be highlighted on the lab reports provided by reciprocating action changes direction every half each potential screening vendor. In addition to revolution, the near-size particles settle down, product recovery efficiency, lab reports must remain in contact with the opening, and separate. state product yields, product quality, and the motion parameters of stroke, frequency, and Longer-stroke machines tend to provide better slope used to achieve the stated results. The blinding control, because they enable a greater Isolator (2019) Ad (130x190)_Layout 1 26/02/2019 15:41 Page 1

information listed above is critical data needed to compare different screener technologies for use in a given application.

Conclusion Vibratory, gyratory, and gyratory reciprocating machines are all available options for a production screener that performs a separation of dry bulk material by particle size. Selecting the proper screener for the application requires an understanding of the application type, the types of motion, the motion parameters, and their respective strengths. Ultimately, these motion parameters, along with the application expertise of the potential screener manufacturer, will determine the screener’s product recovery efficiency and performance in the production process.

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Feature

By Richard Farnish, The Wolfson Centre for Bulk Solids Handling Technology

The process that you don’t want In the overall perception of investment priorities in process plant, filtration systems often are the poor relatives to the value adding aspects of the plant operations. Local dust extraction and ventilation is an obvious exception to this statement due to legislative requirements relating to Health and Safety in the workplace. However, filtration units that serve to capture high concentrations of particles (such as on pneumatic conveying reception vessels) do have the immediate and direct benefit of such legislative requirements. Thus in instances where ‘value engineering’ exercises are implemented for new build or plant uprating projects it can be the case that the filter systems are early victims.

A major problem for attempts at securing adequate CAPEX to support the installation

of a well-designed and efficient filtration system is that, quite clearly, such systems are not ‘value adding’ and such a nominal payback period for expenditure cannot be easily arrived at – making appropriate budget allocation justifications very difficult. The end result for many end users is that systems are installed which can have direct impacts on the plant energy consumption, process stability and in-plant dust emissions.

Returning to basics for a moment, the function of a filter is clearly to capture particles, hold a given volume of material (before a peak pressure drop is arrived at) and finally to release the captured material.

These are clearly obvious requirements, and yet in some instances one or all of these operational aspects can become compromised by changes in; the bulk solids being handled,

transfer rate (increase), the quality of filter elements and/or cleaning system.

Taking these requirements individually, changes in the nature of the bulk solids with which the filter is expected to work are not unusual over the lifetime of many units. Changes in product lines or material suppliers are a common feature for many plants. Such shifts in bulk solid types are usually represented by shifts (sometimes major) in the particle size distributions – the most serious manifestation of which is increased fines content. A corresponding upgrading of the filter media specification sometimes does not follow – with the result that the filter loading burden increases dramatically when in service. Usually this increase in fines loading would be apparent as a reduced time to reach peak pressure drop across the filter.

Fig Typical filter loading characteristics – showing the transition from in-depth to surface filtration Continued >> SHAPA Newsletter | 21

Fig Scanning electron microscope (SEM) image of a wet laid fibre filtration membrane In the event that the filter cleaning is by shaker mechanism (i.e. integral to a batch transfer process step), it may be the case that towards the end of the transfer the back pressure through the system will increase – which can manifest as line stalling (in very marginally configured pipelines) or over pressure of the filter housing (potentially over stressing sealing gaskets and creating fugitive dust). For shaker systems, the filter media will rely on surface capture of particles and release by agitation.

For reverse jet cleaning systems, the particle capture does not rely on bed development on the filter face, but instead a progressive capture mechanism occurs whereby particles are captured within the open fibre matrix of the media and progressively saturate the voids within, following which particle accumulation develops on the face of the filter. Thus the pressure drop development characteristic is of a low initial progression during in-depth capture which then transitions to a higher rate of pressure drop development as particles begin to a bed on the face of the filter. If the process

22 | SHAPA Newsletter

is progressed without cleaning, ultimately the rate of pressure drop decreases due a lack of gas flow as the filter blocks (a situation that would not form part of the standard operating procedure for most types of filter).

Clearly the rate at which the filter develops these pressure drop characteristics will be function of the operating conditions and bulk solid properties. Fine material will tend to lodge deeper into the fibre lay and as the filter progressively loses its functional surface area due to particle accumulation, so the lodgement force will increase in response to higher face velocities. Reverse jet filters are commonly (but not exclusively) applied to continuous processes, and as such are subject to continual cleaning cycles – with the control of the cycles being triggered by either a timer or measurement of pressure drop cross the filter housing.

Taking these two control methods into account for a scenario whereby the process or change in bulk solids has changed the function of the filter (from when it was first commissioned).

In the case of the use of a timer, the issue may now be that the filter is loading with particles more quickly and that peak pressure drop is arrived at before the timed pulse if actioned.

This accelerated loading can lead to deeper embedment of particles and a progressive deterioration in the service life of the filter (towards irreversible blinding).

If the filter is cleaned on a peak pressure drop basis, an increase in loading rate into/onto the filter will result in a higher frequency of pulsing – and in this respect the system can be considered to have almost autonomous operation. An increased frequency of cleaning may not be a major concern in the early stages of filter deterioration, but a concern can be that the frequency of pulse delivery may begin to approach or exceed the ability of the external air reservoir to recover full pressure between pulses (i.e. insufficient time). The result of reducing pressure availability will be a weakening pulse (and air induction if a venturi nozzle is installed) –hence cleaning efficiency reduces and the rate of filter deterioration speeds up.

It should be noted that over the life cycle of a filter the pressure drop is initially dominated by the in-depth and surface particle capture, but over time it is the irretrievably lodged particles within the filter media that dominate pressure drop.

If the filter becomes sufficiently blocked and pressure/air progression through filter limited, an over pressure of the ‘clean’ side of the filter can result that can overload gaskets and dust seals. Such a break though of particles can be readily mobilised through the process hall with the finer particle content remaining airborne for substantial periods of time and hence transporting widely (even beyond the immediate process).

Although this article is clearly only dealing very lightly with engineering and physics of filter operation, it is hoped that the casual reader can gain an appreciation for piece of equipment that is often largely ‘out of sight’ and often ‘out of mind’ – until problems start of course!

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SHAPA Newsletter | 23

Schenck Process ESP Solutions Enable Emission Compliance in Cement Plant Application The ModuPower™ MPX, from Schenck Process has been designed and proven to improve collection efficiency of harmful particulate matter (PM emissions), of any electrostatic precipitator, by increasing the average power into the process, regardless of application.

The ModuPower™ MPX Switch Mode Power Supply (SMPS) utilizes high frequency IGBT (Insulated-gate bipolar transistor) switching to reduce secondary voltage ripple in any ESP (Electro Static Precipitator) from 30% to 3%, when compared with conventional power

supplies. The reduced voltage ripple results in higher than average voltages and faster migration velocities. Due to the VI ((Voltage–current curve) relationship of the ESP, a higher average voltage results in higher secondary currents, increasing the rate of particle charging. A larger quantity of charged particles and faster collection rate of those charged particles results in a significant increase in the performance of any ESP. To ensure accurate government compliance to lower plant emission rates, Schenck Process received an order from a customer working in the cement industry, to replace a conventional TR Set (Transformer Rectifier Set) with a High Frequency TR Set (ModuPower) in Rajasthan, India.

Prior to contacting Schenck Process, the client had installed a potential solution, a Mid-Frequency Transformer Rectifier controller/set (MFTR), with the intention to lower their emission rates, however the result were not sufficient.

As a result, the customer contacted Schenck Process to discuss potential solutions to meet the government emission regulations.

Schenck Process was able to utilise their process expertise to provide the customer with performance estimates for a variety of scenarios. The confidence generated by this analysis prompted the customer to quickly adopt the proposed solution.

Schenck Process provided a complete system, which included an Electrostatic Precipitator (ESP) inspection and rectification services, bundled with a HFTR (ModuPower™ MPX).

After the HFTR (ModuPower™ MPX) installation, the outlet emission achieved well below the original and within the government limits and improved the ESP performance significantly. Without careful consultation from specialists that covered ESP solutions for air filtration, the results could have been very different.

For enquiries relating to ModuPower and ESP solutions, please email Elavarasu Jayakumar, Filtration & Environmental Controls Manager, j.elavarasu@schenckprocess.com

www.schenckprocess.co.uk | enquiries@schenckprocess.co.uk

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