lesson11Marine pumps轮机英语阅读.pptx

船用泵类型与结构

Lesson11Typeandconstruction

ofMarinepumps;1.Apump泵isamachineusedtoraiseliquids液体fromalowpointtoahighpoint.

Alternativelyitmaysimplyprovidetheliquidwithanincreaseinenergyenablingittofloworbuildupapressure(建立压力）.

Thepumpingactioncanbeachieved（实现，获得）invariouswaysaccordingtothetypeofpumpemployed.

;

Thearrangementofpipework,theliquidtobepumpedanditspurposewillresultincertainsystemrequirementsorcharacteristics[?k?r?kt??r?st?ks]（特性）thatmustbemetbythepump.

管路布置、需要泵送的液体,以及其目的将产生特定的系统需要或特性,这些都要由泵来满足。

;2.Thepumpsusedonboardshipcanbedividedintotwomaincategories种类,displacementpumps容积泵andthecentrifugalpumps离心泵.

Theycanbebrokendownintothreeclasses:(1)reciprocating往复泵,(2)rotary回转泵,and(3)centrifugal.它们还可细分成3种:(1)往复泵，(2)回转泵，(3)离心泵。

Underreciprocatingarethedirectacting,power,andcrank-flywheeltypes.

往复泵又分为直接作用式、动力驱动式、曲轴飞轮驱动式等;

;;Undercentrifugalarethevolute蜗壳,diffuser导轮,mixed-flow混流,axialflow轴流andturbine漩涡orregenerative[r??d?en?r?t?v]再生types.

离心泵可分为蜗壳式、导轮式、混流式、轴流式、旋涡式及再生式。

;3.Thedisplacementpumping容积泵actionisachievedbythereductionorincreaseinvolumeofaspacecausingtheliquid(orgas)tobephysicallymoved.

容积泵的泵作用是通过增加或减少液体被实际移动的腔室容积。

Themethodemployediseitherapistoninacylinderusingareciprocatingmotion往复运动,orarotatingunit旋转装置usingvanes叶片,gears齿轮orscrews螺杆.

所采用的方式或者是套筒内做往复运动的柱塞或者是使用叶片、齿轮或螺杆的旋转装置。;4.Areciprocatingdisplacementpump往复泵isshowndiagrammatically[da??ɡr?m?t?kl]inFig.11-1,todemonstratetheoperatingprinciple.

图11-1为往复容积泵的工作原理示意图。;4.Thepumpisdouble-acting双作用,thatis,liquidisadmitted进入toeithersideofthepistonwhereitisalternately[?lt?n?tli]交替drawninanddischarged.

该泵是双作用泵，液体可以进入柱塞的两侧交替吸??。;4.Asthepistonmovesupwards向上,suction吸入takesplacebelowthepistonandliquidisdrawnin,thevalvearrangement布置ensuringthatthedisch