n.回流；逆流

This would create an air gap to eliminate any possible backflow. 這將產(chǎn)生一個氣隙以消除任何可能的回流。

In the event of negative supply pressure such contaminated fluids will not backflow to the supply source by backsiphonage. 萬一存在這種污染流體的反壓力，則要避免由于反虹吸而回流到供應水源中。

Furthermore, the main reason of the axial backmixing of the liquid is the liquid backflow which induced by the reverse flow of the bubbles. 計算結果表明，在逆流操作中液相軸向返混主要是由于氣泡的逆向運動誘導產(chǎn)生的液相回流引起的。