Typical tasks for SIGMA plate heat exchanger in food processing are:
- Short-term heating of gelatine
- Short-term heating of basic materials
- Cooling of yeast wort
- Cooling of preliminary dough
- Hot water boiler
- CIP heater
Application example: Cooling of liquid yeast
One of the market leaders in the manufacture of baking yeast in Germany relies on proven Schmidt plate heat exchangers for the cooling of liquid yeast. Since the end of 2000, various stainless-cladded equipment has been used for this work. During the production of baking yeast, exothermic heat results from the addition of sugar / molasses with the blowing-in of air (fermentation). This heat is dissipated with our equipment in five individual fermentation systems (up to 3,800 kW / unit). The cooling is implemented in batch-operating mode over a period of approx. 20 – 24 hours per batch. The equipment is cleaned in the CIP process once per day for approx. 45 minutes with hot water at 100°C. Due to the high temperatures and the chloride content in the cooling water, the plate material AVESTA 254 SMO has been used. Once per year the plate heat exchangers are opened and mechanically cleaned . The customer is so satisfied with the above equipment, that a further cooling line was equipped in spring 2005 with a new plate heat exchanger from Schmidt-Bretten.
Application II, two-stage cooling of liquid yeast
In the pre-cooler, the liquid yeast (dynamic viscosity of approx. 150 mPas) is precooled to <19°C by means of cooling water. After that, the yeast reaches a separator and is then cooled to <3°C in an aftercooler by means of ethylene glycol. Plate material is AVESTA 254 SMO. The CIP cleaning is implemented by evaporation with saturated steam, and this equipment is likewise opened for mechanical cleaning only every 1-2 years.