Another problem can occur rarely if backflow of process gas is permitted into the secondary air feed line . 如果工艺气体回流入二段空气管线，能发生另外的很少发生的问题。
The trickling filter and activated sludge efficiencies cited required primary sedimentation and effluent circulation . 列举的生物滤池与活性污泥法的效率需要初次沉淀和回流。
the diphenylamine was deuterated by refluxing with a mixture of heptane and for an hour. 将二苯胺与正庚烷和的混合物加热回流1小时，可使二苯胺重氢化。
The trickling filter and activated sludge efficiencies cited required primary sedimentation and effluent circulation . 列举的生物滤池与活性淤泥法的效率就需要初次沉淀和回流。
the diphenylamine was deuterated by refluxing with a mixture of heptane and for an hour. 将二苯胺与正庚烷和的混合物加热回流一小时，可使二苯胺重氢化。
The sludge is passed under a vacuum pump and allows the water to pass through a discharge or recirculation drain . 用真空泵除去污泥的固体含量而该泥水则经排水渠或回流渠排出。
Disturbances in the recirculating flow regime can produce related variations in the heat release rate in the primary mixing region . 回流区域内的扰动可使主要混合区内热量释放发生相应的变化。
Reaction is carried out under a fractionating column that allows aldehyde to pass but returns alcohol to the reaction vessel . 反应是在装有分馏柱的反应器中进行的，分馏柱能让醛通过但使醇回流到反应器中。
