Gareth McCabe, Dairy Sector Specialist at Christeyns Food Hygiene, discusses the complexities of membrane cleaning.
In the food sector, the dairy industry has developed the most advanced filtration procedures for concentration and fractionation of molecules from milk and its derivatives. At Christeyns Food Hygiene, we work with a number of dairy specialists and membrane hygiene is one of the many elements of the very specific cleaning regimes that are a part of day to day production.
Membrane filtration is widely used in the dairy industry and is a proven method for separating one substance from another. Inevitably, soiling occurs during this stage of production, leaving a residue on the membrane surface, known as Membrane Fouling. This complex detritus needs to be eliminated thoroughly in the cleaning process but any damage to the membranes caused by the cleaning, could result in production down time and potential costly replacement.
The challenge is that membranes are easily damaged by chemicals. The soiling is pushed into the membrane surface at high pressure during processing so the clean has to be thorough and effective and carried out after each production run to remove both organic and inorganic material deposited on the surface from the fluid stream.
This cleaning process is technically known as membrane recovery, explains Gareth.
The membranes however are delicate and will not tolerate pH outside of the specification or high temperatures. Unlike traditional dairy equipment, you can’t therefore just put more caustic or acid in the plant, turn the temperature up and circulate until it’s clean. A gentle but effective cleaning system is the answer.
It is vital to use the correct chemistry at the correct dosage for the correct circulation time to achieve a good clean. Each regime must be optimized with respect to concentration, order and duration of cleaning steps, temperature, pressure, and flow rate.
Chlorine has long been an essential component in food manufacturing, industrial and wastewater treatment due to its ability to eliminate most pathogenic microorganisms. It can however inhibit the performance of membranes used in the filtration process and leave chlorite and chlorate traces in end product and lead to membrane replacement.
Working with sister companies within the Christeyns group, Christeyns Food Hygiene has developed a range of specially blended products that are able to effectively clean plant equipment with minimal use of chlorine.
“The new cleaning system comprises alkali, acid and enzyme technology specifically developed to remove complex soil types in dairy, beverage and brewing industries with limited use of chlorine,“ states Gareth. “The system caters more accurately to the modern production plant with an improved surfactant structure and more complex enzyme chemistry.”
This new chemistry is suitable for cleaning a range of membrane types including spiral wound, thin film composite, plate, frame and ceramic style filtration systems.
The Mida Memcare range includes five products: a medium caustic detergent, 504: a low foam detergent, 512; a Buffer, designed to correct alkaline pH conditions; Enzy, a formulated product for the removal of organic soiling by enzymatic breakdown of proteins and fats; and 518, a liquid additive based on seven enzymes that unblocks membrane pores and increases their permeability.
It is therefore possible, with products like this, to reduce the chlorine in the cleaning chemicals to a minimum so as to increase the membrane life but still ensure that there are no residual chlorates or chlorites in product, retentate or permeate.
Complex chemistry like this, combined with the skills and knowledge of a specialist team, can also lead to a reduction in energy and water consumption in both cleaning and production. Micro results and flux rates reflect the standard and integrity of the cleaning regimes in place and are the best test of efficiency.
Christeyns Food Hygiene currently work with companies such as Muller, Tomlinson’s Dairy and First Milk in the UK, supplying the Memcare range of cleaning products.
For further information contact Gareth McCabe 01925 234696 gareth.mccabe@christeyns.com
