英语语法分析

The actual operation shows that the newly-designed impellers were safe.

实际运行结果表明，改型后的叶片运行是安全的。

Frequently clear the attachment on impellers to avoid load increasing, so as to not damage aerator by overload.

应经常清除叶轮附着物，防止负荷增加，以免造成过载运行而损坏增氧机。

Cantilever pumps are available with closed, open or vortex impellers to meet the requirements of different applications.

悬臂泵叶轮有闭式、开式、旋流式三种型式，以满足不同的应用需要。