Pumps nd Pumping Stations中英对照.docVIP

Pumps and Pumping Stations Pumps and pumping machinery serve the following purposes in water systems: (1)lifting water from its source（surface or ground），either immediately to the community through high－lift installations，or by low lift to purification works；(2)boosting water from low－service to high－service areas，to separate fire supplies，and to the upper floors of many－storied buildings；and(3)transporting water through treatment works，backwashing filters，draining component settling tanks，and other treatment units，withdrawing deposited solids and supplying water （especially pressure water） to operating equipment. 在供水系统中，泵和泵送机械有以下的服务目标：（1）从水源（地表水或地下水）提水，或者通过高扬程泵把水迅速送到居民区，或者用低扬程泵将水打入净水厂；（2）将水从低压供水区增压至高压供水区、单独的消防用水源和高层建筑物上层；（3）令水进出处理厂，在此过程中，反冲过滤池，使水由沉淀池和其他处理构筑物流出，抽排沉淀固体和向运行设备供水（特别是压力水）。 Today most water and wastewater pumping is done by either centrifugal pumps or propeller pumps. 如今大多数给水和废水的泵送都是由离心泵或轴流泵来完成的。 How the water is directed through the impeller determines the type of pump.?There is (1) radial flow in open－or closed－impeller pumps， with volute or turbine casings，and single or double suction through the eye of the impeller，(2)axial flow in propeller pumps, and (3)diagonal flow in mixed－flow，open－impeller pumps. 水穿过叶轮时的流向确定了泵的类型：（1）在开式或闭式叶轮泵中表现为轴向流，该泵具有螺旋形或涡轮式外壳和水单吸或双吸进入叶轮的方式；（2）在轴流泵中表现为轴向流；（3）在开始叶轮混流泵中表现为混流。 Propeller pumps are not centrifugal pumps. 轴流泵不是离心泵。 Both can be referred to as rotodynamic pumps.?这两种泵都可以称为旋转动力泵。 Open－impeller pumps are less efficient than closed－impeller pumps, but they can pass relatively large debris without being clogged.开式叶轮泵的效率不如闭式叶轮泵，但其可令相当大的漂浮物通过而不致被堵塞。 Accordingly, they are useful in pumping wastewaters and sludges.因此，它们在提升废水和污泥是大有用场的。 Single－stage pumps have but one impeller, and multistage pumps have two or more, each feeding into the next higher stage.单级泵仅有一个叶轮；而多级泵则有两个或两个以上的叶轮，且每一级叶轮都将水打入下一级叶轮中。 Multistage turbine well pumps may have their motors submerged, or they may be driven by a shaft from the prime mover situated