開放羽根をもつ高速うず巻ポンプに関する一考察

抄録

Performance of pump with open impeller is much affected by running clearance between the impeller vane and the stationary casing. A few researches on this problem have reported in past, but most of them are reports of experiment with special models. It is not enough to estimate the performance of other open type construction pumps by those data only. In the present paper, authors report some data for estimation of the performance of open impeller construction. The results are followings : 1. Both head and quantity of a pump reduce with increasing of the ratio, running clearance / vane breadth, and the percentage of the reduction will be expressed by a function of specific speed of pumps. 2. Pump efficiency improves comparing with it of closed impeller but drops in proportional to the ratio of running clearance to vane breadth. When the running clearance increases to some value, pump efficiency is inferior to it of closed impeller construction and its limit is in range of engineering practice.