Performance of Cyclone Type Air-Cleaner as Applied to Internal Combustion Engine : 2nd Report, The Effects of Engine Running Speed on the Collection Efficiency

Abstract

The effects of engine running speed on cyclone dust collection efficiency were researched by motoring tests changing the mean inlet velocity and engine running speed by adjusting throttle valve of carburettor. It has been found out that, with exception of high engine running speed accompanied with extremly high inlet velocity, the effects of engine running speed on dust collection efficiency are generally negligible compared with the effects of inlet velocity. The efficiency decreased sharply with high engine running speed accompanied with extremly high inlet velocity. Experiments revealed that cause of this was not that the efficiency of cyclone with steady flow decreased sharply at high inlet velocity, but that the suction air flew back again and blew up the dust particles deposited in the dust box. Further, the effects of valve timing of the engine on the amounts of back flow were tested.