船用离心泵抗泥沙防泄漏系统的设计方法

针对我国船舶用离心泵因海水泥沙破坏而造成严重泄漏的问题,在船舶用离心泵设计上采用一种背叶片流体动力密封和机械密封相结合,同时增加清洁水系统来对泥沙水进行分离处理的综合抗泥沙防泄漏方法,即利用旋流器的分离特性将海水中的泥沙进行分离,产生清洁水用于机械密封的润滑和冷却,基于流体动力密封原理,利用叶轮上的背叶片带动液体旋转所产生的离心力,使液体甩向叶轮出口,起到保证洁净水系统压差、阻止泥沙进入轴端密封的作用。进行了旋流器特性研究、机械密封冷却液计算、叶轮背叶片设计、匹配计算,并给出了具体的设计计算方法。

Design method of sand resistent and leak proof system for marine centrifugal pumps

Seawater and sand may cause serious leak to the marine pumps. A new solution was developed by adapting hydraulic seal combined with mechanical seal,also with the assistance of a system which separate the sand from water.That is to say,clean water separated from seawater by cyclone separating device can be employed to lubricate and cool the mechanical seal.Based on the principle of hydro-dynamical sealing,with the effect of centrifugal force produced by the back vane,water will be thrown to the impeller outlet to ensure the pressure grads of water purify system and prevent sand from coming into shaftend seal.Concrete scheme of design was educed to four steps: study of the characteristic of cyclone device,calculation of cooling flux for the mechanical seal,designing and matching calculation of back vanes.The solution has achieved good effect in many applications in recent years.marine centrifugal pump;sand defend;leak proof; cyclone mechanical seal;vice-leaf