Operating at the forefront of thermal technology, HRS has developed the Unicus Series of reciprocating scraped surface heat exchangers to solve tough heat exchange challenges.
Scraped surface heat exchangers (SSHE) have been used for difficult heat transfer applications involving viscous fluids or where fouling is an issue, such as evaporation processes. The most common type of SSHE uses a rotating shaft with blades or augers which scrape the surface of the tube. HRS’s R Series is based on this approach but the design is not optimal.
The HRS Unicus Series is specifically designed to provide the improved heat transfer of a traditional SSHE, but with a gentle action to preserve the quality and integrity of delicate food products such as cheese, yoghurt, ice cream, meat paste, and products containing whole pieces of fruits or vegetables. Other applications where the Unicus Series has been beneficial include handling meat slurry and mince, and processing yeast-malt extracts.
The hygienic design uses a patented stainless steel scraping mechanism which moves hydraulically back and forth within each interior tube. The movement minimises potential fouling by keeping the tube wall clean, and creates turbulence within the material. Together, these actions increase the rate of heat transfer, creating a highly efficient process ideal for viscous and high fouling materials.
The Unicus Series has proven useful in handling viscous food products where texture and consistency are important attributes. Effective heat transfer can be carried out at low pressures, overcoming problems like the shearing of creams and sauces when subjected to excess pressure.
Each Unicus SSHE consists of three elements: a hydraulic cylinder and power pack (although in smaller units a pneumatic cylinder can be supplied instead), a separation chamber to ensure hygiene and preserve product separation from the motor, and the heat exchanger itself. The Unicus Series is also fully scalable. A key feature is the specially designed seals which separate the inner tube from the separation chamber, tailored to the product application. These seals prevent leakage of the product and ensure internal and external hygiene.
A standard range of models for food processing provide heat transfer areas from 0.7 to 10m2, while larger models up to 120m2 can be made for specific uses.
The Unicus Series excels in evaporation applications, where prevention of fouling is particularly important. HRS has a specific version of the Unicus for use in evaporation units.