5 minute read
Cleaning technology offers
efficient selection for greater profits
When looking at cleaning technology for cleaning in place (CIP) there are two frequently asked questions: Will it clean my tank and how much does it cost?
Current advancements in cleaning technology now mean that we are not just able to clean a customer’s tank, but also save them time and money in the process. This is the view of James Simmonds, product manager cleaning technology.
There are three basic types of technology; static spray balls, single axis rotating and duel axis rotating. Each has its merits, and savings can be made by choosing the right type of equipment to use.
There are four inter-dependant factors which influence the result of a CIP cycle. In 1959, Dr Herbert Sinner combined these into what is now referred to as Sinner’s Circle.
Sinner identified four key elements of cleaning: Time, temperature, chemical and mechanical action. He recognised that by increasing one factor, we can make savings on one or more of the remaining factors.
When looking at any CIP cycle the costliest elements are generally time (lost production time), temperature (energy required to heat cleaning liquids) and the chemical or cleaning liquid itself (both in terms of the cost to buy the liquid and equally, in today’s climate, the cost of effluent treatment).
AWH Cleaning Technology focuses on the fourth factor, mechanical action. Mechanical action is the physical force used on the soiled area and with minimal investment in moving from one type of equipment to another it is possible to greatly increase productivity while reducing running costs significantly.
The oldest, and currently most common, type of technology used is the static spray ball. With no moving parts and proper care it is (potentially) maintenance free and, coupled with low investment costs, it is often the first choice of both vessel manufacturer and end user alike.
Static spray ball and tanko MX 125
Operating at low pressure and with high flow requirements the cleaning function of a static spray ball is to produce points of impact on the vessel walls (where the jets from the holes hit).
We rely on the volume of liquid running down the sides of the tank (a free falling film) for the majority of the clean. This leans the suitability of static spray balls more towards smaller vessels, as less overall volume of cleaning liquid is required to cover the tank walls, and easily removed soils (such as light liquids) as less mechanical action is required to remove them. As vessels increase in size or soiling becomes more difficult to remove we begin to look at single axis rotating cleaners like the AWH Tanko S Series.
While still operating at low pressure, single axis rotating devices step up the level of mechanical action. The cleaning is carried out by a series of high energy droplets, generated by fast rotation and precision cut slots, impacting instantly and repeatedly against the soiling on all surfaces.
Relating back to Sinner’s Circle, more energy is now added to the cleaning process, reducing both the amount of cleaning liquid required and the time needed for cleaning. This leads to a direct cost saving.
As an example of this, a study was carried out at one of the largest and most renowned German breweries who had exchanged large static spray balls in 76 of their 700m3 fermentation vessels for AWH Tanko S50 rotating heads.
AWH TANKO S SERIES
After extensive testing they achieved a 38% reduction in cleaning (lost production) time, a 58% reduction in fresh water consumption (and so also 58% reduction in the amount of effluent they had to treat) as well as 39% reduction in caustic needed. In total this translated into a saving of €51.60 per tank, per CIP. The payback period per tank by changing technology was under 10 CIP cycles.
When considering larger tanks (typically >5m diameter) or heavy levels of soiling often the most effective technology is multi axis jet cleaners. This type of equipment is slow rotating and builds up its wash pattern over a certain period of time.
Although more costly from a capex point of view than the previous technology types their efficient use of the cleaning fluid and high level of mechanical action mean considerable savings on time and chemicals can be made.
As an example, the AWH Tanko S50 will clean tanks up to 6m in diameter but at 3 bar requires 15m3/h flow to do so. The AWH Tanko MX125 multi-axis jet cleaner will clean the same size tank at a pressure of 5 bar but will only require 4m3/h to do so.
Having said this, it is not always the case that a multi-axis jet cleaner is the best solution. It is important to consider the nature of the soil you are trying to remove.
A 5m diameter tank with a light soil type may be cleaned quicker with a fast rotating single axis cleaner (which instantly covers the surfaces) than a slower rotating multi-axis jet cleaner. It is important to identify the cross over in realised value between time taken and flow rate per hour required.
THE AWH TANKO MX SERIES
Cleaning technology is most commonly operated / driven by the cleaning liquid flowing through it. Further efficiencies can also be made by using an externally driven jet cleaner. These are usually driven by either an electric motor or by compressed air such as the AWH Tanko JX range.
As these jet cleaners are not relying on a certain volume of water to drive them flow rates are often much lower than conventional media driven jet cleaners. At 5 bar pressure the media driven AWH Tanko MX125 with 4mm nozzles requires 4m3/h flow rate whereas comparably the externally driven Tanko JX70 at the same pressure only requires 1.25m3/h.
In summary selecting the correct cleaning technology is not always a straightforward process. The above are examples of the types of technology available to users but even within these three basic groups there are many variations on a theme, with each variation serving some specific condition.
It is easy enough to choose a cleaner based on tank size and price, but without taking into consideration the large number of other aspects of a cleaning application the chances of selecting the best suited equipment are slim, and a golden opportunity to boost profits may be lost.
It is this holistic approach to appraising a cleaning application that allows AWH Cleaning Technology to achieve tangible cost savings and process optimisations for customers. •
About the author: James Simmonds is the product manager cleaning technology, Armaturenwerk Hötensleben.
