The drawing method for the double channel impeller is studied.It is found that there is an in-conformity between the dimensions of plane-view and pinacoid-view of fluid cross-section.

摘究了双流道污水泵叶轮常用的图纸表达方法，发现平图上的断投影结果与轴图中确定的断形状尺致的问题。

The sewage channel chokes.

这条污水道塞住了。