牧草の熱風乾燥機に関する研究 (第2報)
プロパン牧草乾燥機用簡易熱交換器の作製とその性能について
1963 年 25 巻 2 号 p. 113-118
詳細
1963 年 25 巻 2 号 p. 113-118
In the previous report (Studies on Hay Dryers with Heated Air, (I)) the fuel cost was about 1.65yen per kilogram of dried hay, whereas the depreciation cost was 1.50 yen, in case field cured hay with 35-40% moisture content (wet basis) was used and about 10tons of hay were prepared annually. Recirculation of exhaust gas is one of the methods to increase the overall thermal efficiency and reduce the operation cost. The LP gas dryer which showed a better thermal efficiency in the previous report, however, maintained its exhaust moisture content at nearly 100% for 1/2-2/3 of the operating time which was about one hour and the high moisture content seemed adverse to a recirculation system. A simple plate type heat exchanger consisting of 23 zinc-coated roofing iron sheets was designed and tested with the LP gas dryer without any change in the heater and blower unit. About 20% of heat saving was obtained with it. Since there is a possibility of making the exchanger a compact unit for saving construction material and installation space, further improvement and experiments are intended in the future.
