Rotor gives low shear heat treatment a new twist
26 September 2011
A new, specially-designed rotor, makes the Alfa Laval Contherm scraped-surface heat exchanger even more ideal for processing shear-sensitive, particulate-bearing foods such as soups, sauces, desserts and confectionery.
The new rotor can be incorporated into new-build exchangers or quickly and easily retrofitted to existing Contherms. Its development was prompted by a growing consumer preference for prepared foods containing particulates that are regular in size, texture and flavour. To arrive at the version now being introduced, Alfa Laval experimented with a number of options which they field-tested at food plants specialising in a variety of particulate and shear-sensitive products.
The development team was tasked with creating a rotor that maintained shape and texture of the foods being tested. Different rotor configurations were tested in the same plants to ensure that the results could be compared precisely. The clear winner at the conclusion of the tests was a 51 mm diameter rotor with two support pins per scraping blade that had clearly out-performed all of the other rotors tested.
The 51mm diameter rotor provides 36mm of clearance between the scraping blade and the rotor’s surface; providing 44% more annular space for product and enabling free passage for even large pieces of product. Confining the number of support pins to two also reduces the volume of rotor surface in the product zone by at least 44%. This dramatically reduces the risk of shear and product damage as food is being processed.
In a Contherm, blades scrape the heat transfer surface at pre-determined intervals to reduce fouling and prevent hot or cold spots developing. Rotor speed is crucial to the success of the operation and control is provided by variable speed motors, enabling process engineers to determine the rotor speed that suits their product – or products – best.
For further information, visit www.alfalaval.co.uk or contact:
Marketing & Communications Manager
Alfa Laval Limited
Phone: 01276 63383