Method and installation for heating drying air essentially by recovering the enthalpy contained in the humid air leaving the drying apparatus

摘要

This installation is based on the combination of three means which are: - high performance heat exchangers A, A'; B, B' using intermediate heat-exchanging fluids in order to obtain small temperature deviations; - a heat pump 1 using R114 making complete use of the considerable possibilities of the undercooling of the R114 by virtue of these heat exchangers A, A'; B, B', which leads to COPs greater than 4; - a unit 3 for mechanical compression of the steam produced very economically in a Flash balloon (container) 2 fed by the heat pump 1, which compression enables the air to be heated to temperatures lying between 150 DEG C and 200 DEG C. The synergy of these three means is fully confirmed by the operating result of the method which enables the incoming air to be heated from -10 DEG C to 170 DEG C, with a general COP of the order of 3.5, which results from recycling economically a considerable part of the enthalpy of the air leaving the drying installation. The recycling rate may reach 75%. IMAGE