According to the present invention a method for heat recovery in a device for the sterilization of biological material is provided. The present method eliminates the risk of contaminating the sterilized effluent with unsterilized biological material via the heat recovery system. In a device according to the invention, a heat recovery circuit is provided for transferring heat from the sterilized effluent stream to the biologically hazardous feed stream. Protection against contamination through leaks is obtained by maintaining at all times a pressure difference preventing biologically hazardous material from bypassing the heat treatment and flowing in the direction of the sterilized material.
