Case study No. 5:
Exhaust air purification in food processing

Initial situation

Modern methods of waste management also play a major role in food processing. The biological residues are treated in thermal/biological processes. The resulting damp exhaust air must also be cleaned and dehumidified in order to avoid pollutant leakage and swathes when it is released into the environment.
A large volume flow of exhaust air is discharged from the so-called bio-regenerators with approx. 40°C and high humidity and must be cooled and dehumidified. The sensitive and latent heat released can be used again in other systems and thus further reduces the environmental impact.


Our customer Ventilex B.V. supplies an exhaust air purification system for a sausage factory in Russia. Since the pollutants contained in the exhaust air are corrosive, metallic heat exchangers cannot be used for the cooling of the exhaust air, as these would lead to a defect due to corrosion after a short operating time. A standstill in the exhaust air treatment also leads to expensive production failures and therefore a completely corrosion-resistant heat exchanger must be used on the exhaust air side.


The Calorplast Gas-Water Heat Exchanger made of polypropylene (PP) has been proven in several similar plants for many years. The heat exchanger is specially designed and manufactured in size and performance for the task and can be easily mounted on the bio-regenerator.


The entire system is designed for an exhaust air volume flow of 100,000 m3/h and returns an output of 1.8 MW to the preheating of the fresh air at the optimum operating point. The saving of CO2 amounts to approx. 1,800 t per year, for the average annual temperature.