METHOD AND EQUIPMENT FOR THE ENERGY-SAVING DRYING ESPECIALLY OF HEAT-SENSITIVE AS WELL AS OF TOXIC AND/OR SMELLY GAS PRODUCING MATERIALS.

摘要

In course of the process air or a gaseous medium is used in an open or in a closed system, by the aid of which the moisture content of the material to be dried is extracted. The drying medium is brought into contact with the humidity absorbing solution in the absorber; between the steam having been obtained in such a manner and the drying medium heat exchange is taking place; the steam is condensed, the drying medium is heated, at last the condensate is discharged into the atmosphere, while the heated drying medium is recirculated in the drying process. In case, if sludge has to be dried and to be annihilated, the sludge - having been pre-condensed to a solid matter content of 30% - is dried to the moisture content of 1- 2% by means of the drying medium, hereafter - in a given case by using an auxiliary firing - the sludge is burnt in the combustion space of the expeller. The equipment provided with an open or closed drier operating with a heated drying medium, incorporates an absorber having been arranged in the path of the stream of the drying medium. In the absorber there is a liquid distributor introducing the humidity absorbing solution. Furthermore the equipment comprises an expeller for the removal of the humidity content of the humidity absorbing solution and the steam space of said expeller is connected to the heat exchanger arranged in the stream path of the drying medium leaving the absorber, while the liquid space is connected to the liquid distributor. When the sludge is to be dried and burnt, the equipment comprises a sludge drier, which is connected to the firing chamber of the furnace through the drying line for the dried sludge.