Process and appliance for drying pourable material

摘要

The invention relates to a process and an appliance for the optimisation of energy usage in the process for drying pourable material in a shaft dryer, the drying zone of which consists of several drying elements arranged one above the other. The aim of the invention is a high efficiency and low cost for the production of the drying medium. The object of the invention is to design the inventive solution so that exhaust gas emerging from the lower drying elements is separately collected, a portion of it is sucked off, mixed with hot air and/or combustion gas in dependence on its humidity and temperature, and is fed to the lower drying elements as the drying medium. The remainder of the exhaust gas is fed to the exhaust air in the exhaust air channel. For this purpose a space divider, preferably a flap, is placed in the exhaust air channel and divides it into a collecting chamber, which is connected to a mixing space to which the heat exchanger, combustion space and the lower drying elements are connected. The area of a throughflow opening between the space divider and the channel wall is variable. <IMAGE>