A new and improved method of and arrangement for drying material by utilising the heat of vapour evolved from the material

摘要

532,829. Drying grass &c. TRIGGS, W. W. (Akt.-Ges. Brown, Boveri & Cie.). Sept. 9, 1939. No. 25509. [Class 34 (ii)] Materials particularly agricultural products such as grass are dried by passage through at least two drying chambers one of which has an external supply of heat while the others are heated by heat exchangers supplied with air saturated with vapour mixture from the first drying chamber, and fans circulate fresh air over the heat exchangers and material to be dried so often that at least 50 times as much air by weight passes over the heat exchangers as vapour flows through them during the same time. Grass is fed at a on to a conveyer b at the end of which it falls on to a conveyer f which carries it to an outlet n. The lower conveyer is heated by steam pipes k and vapour given off by the grass is drawn by a fan o into pipes i forming a heat exchanger in the compartment c containing the upper conveyer b. Air is circulated quickly and repeatedly by fans extending along the whole length of the chamber quickly over the 'pipes i and through the grass, thereby condensing moisture in the tubes. In a modification. the conveyers are slightly inclined and the heating pipes are at the upper end of one conveyer. The pipes may be above or at the side of the conveyer.