旋流排螺模型初步试验研究

一些传统的水利血防措施(沉螺池、中层取水等)受多种条件的制约,工程效益难以充分发挥,研究新的水利血防措施势在必行。本研究借鉴旋流排沙的原理,研制了旋流排螺模型,并通过模型试验研究装置内的水流特性及排螺效果。结果表明:流量增大,流速以及紊动强度也随之增大;切向流速的径向分布中,靠近边壁的流速较大;在测流垂线上,切向流速分布中则以表层流速为最大;隔板对水流挤压使得在隔板边缘出现较大的轴向流速;模型内缘的径向流速比外缘径向流速更大。轴向紊动强度的分布为中上层大、底层小。在试验流量下,投入一定数量的钉螺,观测到模型排螺率达100%,表明旋流排螺技术是一种行之有效的排螺工程措施。

Preliminary Model Test of Vortex Basin for Oncomelania Control

As some traditional water conservancy measures for schistosomiasis control (settling basin for oncomelania snail, and middle layer water intake projects) are restricted by a variety of conditions, it is imperative to conduct research on new measures of schistosomiasis control. In this research, vortex basin for oncomelania was developed based on the principles of desilting funnel, and model experiment was carried out to research the flow characteristics and trap efficiency of oncomelania by the vortex basin. Results show that as flow rate increases, the flow velocity and turbulence intensity increases. The tangential velocity decreases by moving from the center of the model towards sidewall along radial direction and by moving from the bottom of model to water surface along vertical direction. Large vertical velocity is found near the edge of deflector caused by the compress of deflector. Radial velocity at the inner edge is larger than that in outer regions. Vertical turbulence intensity in middle and upper part of flow is higher than that in low layer. Under different flow rates, a certain number of oncomelania snails are fed into the model and it is observed that the trap efficiency reaches 100%. It shows that vortex basin for oncomelania is an effective engineering measure.