1、精品文檔精品文檔Less on 11 Type and Con structio n of Marine Pumps第 1111 課船用泵的類型和結(jié)構(gòu)1. A pump is a machine used to raise liquids from a low point to a high point. Alter nativelyit may simply provide the liquid with an in crease in en ergy en abli ng it to flow or build upa pressure. The pump ing action can b

2、e achieved in various ways accord ing to the type ofpump employed. The arran geme nt of pipe work, the liquid to be pumped and its purposewill result in certain system requirements or characteristics that must be met by the pump.泵是用來(lái)把液體從低處提升到高處的機(jī)械。或者可以簡(jiǎn)單地說(shuō)，泵是給液體提供能量從而使液體能夠流動(dòng)或者建立一定的壓力。泵液體的過(guò)程依照所用泵的型號(hào)不

3、同，可以通過(guò)不同的途徑來(lái)實(shí)現(xiàn)。管路布置、需要泵送的液體，以及其目的將產(chǎn)生特定的系統(tǒng)需要或特性，這些都要由泵來(lái)滿足。2. The pumps, which are used on board ship, can be divided into two main groups:displacement pumps and centrifugal pumps. They can be broken down into three classes:(1) reciprocating, (2) rotary, and (3) centrifugal. Under reciprocating are th

4、e direct acting,power, and crank-fly wheel types. Under rotary are the gear, vane, screw and piston types.Under centrifugal are the volute, diffuser, mixed-flow, axial flow and turb ine or regenerative types2 2船用泵可分成兩大類型：容積泵和離心泵。它們還可細(xì)分成3 3 種:(1):(1)往復(fù)泵，(2)(2)回轉(zhuǎn)泵，(3)(3)離心泵。往復(fù)泵又分為直接作用式、動(dòng)力驅(qū)動(dòng)式、曲軸飛輪驅(qū)動(dòng)式等；

5、回轉(zhuǎn)泵可分為齒輪式、葉片式、螺桿柱塞式等。離心泵可分為蝸殼式、導(dǎo)輪式、混流式、軸流式、旋渦式及再生式。圖H-1H-1往菱容積泵示盍圖displaceme nt pump ing容積泵3. The displaceme nt pump ing actio n is achieved by the reduct ion or in crease involume of a space causing the liquid (or gas) to be physically moved. The methodemployed is either a pist on in a cyli nder us

6、ing a reciprocati ng moti on, or a rotat ing unitusing van es, gears or screws容積泵的泵作用是通過(guò)增加或減少液體被實(shí)際移動(dòng)的腔室容積。所采用的方式或者是套筒內(nèi)做往復(fù)運(yùn)動(dòng)的柱塞或者是使用葉片、齒輪或螺桿的旋轉(zhuǎn)裝置。4. A reciprocating displacement pump is shown diagrammatically in Fig. 11-1, to精品文檔精品文檔demonstrate the operating principle. The pump is double-acting, that

7、 is, liquid is admittedto either side of the piston where it is alternately drawn in and discharged. As the pistonmoves upwards, suction takes place below the piston and liquid is drawn in, the valvearrangement ensuring that the discharge valve cannot open on the suction stroke. Abovethe piston, liq

8、uid is discharged and the suction valve remains closed. As the piston travelsdown, the operations of suction and discharge occur now on opposite sides.圖 11-111-1 為往復(fù)容積泵的工作原理示意圖。該泵是雙作用泵，液體可以進(jìn)入柱塞的兩側(cè)交替 吸排。 當(dāng)柱塞上移時(shí)，液體從柱塞下吸入，閥的布置確保了吸液時(shí)排放閥不會(huì)打開。柱塞上 部空間的液體被排出，此時(shí)吸入閥保持關(guān)閉。當(dāng)柱塞下移時(shí)，吸排動(dòng)作相反。5. A relief valve is alwa

9、ys fitted between the pump suction and discharge chambers toprotect the pump should it be operated with a valve closed in the discharge line.如果泵工作時(shí)排出管路閥門關(guān)閉，需要在吸入腔和排出腔之間設(shè)置安全閥以保護(hù)泵。6. Reciprocating displacement pumps are self-priming, will accept high suction lifts,produce the discharge pressure requir

10、ed by the system and can handle large amounts ofvapor or entrained gases.They are, however, complicated in construction with a numberof moving parts requiring attention and maintenance往復(fù)容積泵具有自吸能力， 能產(chǎn)生較大的吸入高度， 達(dá)到系統(tǒng)所要求的排出壓力， 能夠輸送 大量蒸汽或者夾帶的氣體。然而它們結(jié)構(gòu)復(fù)雜，有許多運(yùn)動(dòng)部件需要維護(hù)和保養(yǎng)。7. When starting the pumps the sucti

11、on and discharge valves must be opened. It isimportant that no valves in the discharge line are closed, otherwise either the relief valvewill lift or damage may occur to the pumps when it is started.當(dāng)啟動(dòng)泵時(shí)，必須打開吸入閥和排出閥。 排出管路中的所有閥均應(yīng)開啟，這點(diǎn)很重要， 否則 安全閥會(huì)開啟或者啟動(dòng)時(shí)可能會(huì)對(duì)泵造成損害。8. Screw, vane and gear pumps are exa

12、mples of rotary displacement pumps. All types ofrotary pumps continue to force liquid into the system regardless of the opposition to thetransfer. Due to this, reason, additional protection to these pumps is required or else thepump will continue to build up pressure and finally lead to rupture or d

13、amage to the pump.To avoid this, relief valves are fitted in the pumps. These relief valves are capable ofbypassing entire throughput of the pump. Rotary pumps are highly sensitive pumps andtherefore special care is needed in order to prevent any abrasive material from enteringthe pump which can dam

14、age the helices and clearances in the pump. The startingprocedure of rotary displacement pumps is similar to that for the reciprocatingdisplacement pump.螺桿泵、 葉片泵和齒輪泵都是回轉(zhuǎn)泵。 所有類型的回轉(zhuǎn)泵都能夠把液體壓進(jìn)系統(tǒng)， 無(wú)論輸退 的管路中遇到多大的阻力。 由于這個(gè)原因， 這些泵被要求有附加保護(hù)， 否則泵會(huì)持續(xù)產(chǎn)生很 大的壓力， 最后導(dǎo)致泵破裂或損壞。 為了避免這種損壞， 這種泵必須安裝溢流閥。 這些溢流 閥有能力旁通泵的整個(gè)流量。

15、回轉(zhuǎn)泵是高精密泵， 因此要特別小心以避免磨粒進(jìn)入泵體， 損 壞泵的螺旋線和間隙?；剞D(zhuǎn)容積泵的啟動(dòng)程序和往復(fù)容積泵有點(diǎn)相似。Centrifugal Pump離心泵9. Centrifugal pumps are those where an impeller rotating at highspeed throws the liquid by centrifugal force from the center to the periphery of the impellerwhere the liquid is discharged through the delivery outlet.離心泵

16、泵內(nèi)的葉輪高速旋轉(zhuǎn)， 并利用離心力將液體從葉輪的中心甩向四周，口排出。然后液體從排出精品文檔精品文檔10. A vertical, sin gle stage, sin gle en try, cen trifugal pump for gen eral marine duties isshow n in Fig. 11-2. The pump ing eleme nt is made up of a top cover, a pump shaft, animpeller, a beari ng bush and a seali ng arran geme nt around the shaf

17、t. The seali ng arrangeme nt may be a packed gla nd or a mecha ni cal seal and the beari ng lubricati onsystem will vary accord ing to the type of seal. Replaceable wear rings are fitted to theimpeller and the casing. Centrifugal pumps, while being suitable for most general marineduties, are not sel

18、f-priming and require some means of removing air from the suctionpipeline and filling it with liquid.圖 11-211-2 為普通船用單級(jí)、單側(cè)吸入直立式離心泵。泵送部件由端蓋（頂蓋）、泵軸、葉輪、軸承套和環(huán)繞著軸的密封裝置組成。密封裝置可以是填料壓蓋或者是機(jī)械軸封，軸承潤(rùn)滑系統(tǒng)的類型由密封裝置的類型決定?？梢愿鼡Q的密封環(huán)分別安裝在葉輪和泵殼上。盡管離心泵適用于船上的大多數(shù)一般用途，但是不具備自吸能力，需要利用一些方法排除吸入管路的空氣， 注滿液體。圖單缸裔心泵11. Whe n start i

19、ng a cen trifugal pump the suct ion valve is ope ned and the dischargevalve left shut: then the motor is started and the priming unit will prime the suction line.Once the pump is primed the delivery valve can be slowly opened and opening or closingthe delivery valve can regulate the quantity of liqu

20、id. When stopping the pump the deliveryvalve is closed.啟動(dòng)離心泵時(shí)，打開吸入閥，關(guān)閉排出閥，然后開啟馬達(dá)，引水裝置就會(huì)為吸入管引水。引 水后即可慢慢開啟排出閥，開大或關(guān)小排出閥以調(diào)節(jié)液體的排出量。停止用泵時(shí)，先關(guān)閉排出閥，然后再關(guān)閉馬達(dá)。12. Regular maintenance on the machine will involve attention to lubrication of the shaftbeari ng en suri ng that the shaft seal or gla nd is not leak in

21、g liquid. Un satisfactory operation or loss of performa nce may require mi nor or major overhauls. Com mon faults, suchas no discharge, may be a result of valves in the system being shut, suction strainersblocked or other faults occurring in the priming system. Air leaks in the sucti on pip ing, a精品

22、文檔精品文檔choked impeller or too tight a shaft gla nd can all lead to poor performa nee.離心泵的常規(guī)保養(yǎng)需要注意檢查軸承的潤(rùn)滑，確保軸封或密封壓蓋無(wú)漏液現(xiàn)象。如有運(yùn)轉(zhuǎn)不良或性能下降，可能需要進(jìn)行小修或大修。常見的故障，比如沒有排液，可能是由于系統(tǒng)的閥被關(guān)閉，吸入濾器堵塞或是引液系統(tǒng)的其他故障。吸入管路漏氣、葉輪阻塞或軸封太緊都會(huì)導(dǎo)致性能差。13. Reciprocating pumps and rotary pumps are positive displacement type because theydisch

23、arge a near constant amount of liquid regardless of pressure. If the discharge valveis closed, they build up a bursting pressure or stall their motor. Cen trifugal pumps are nonpositive and fairly low pressure un its. Here a closed discharge valve will not causeexcessive pressure to build up.往復(fù)泵和回轉(zhuǎn)泵

24、是正容積泵， 因?yàn)樗鼈兡茌敵鰩缀醵康囊后w而與壓力無(wú)關(guān)。若排出閥關(guān)閉，它們將產(chǎn)生破壞性壓力或使電動(dòng)機(jī)堵轉(zhuǎn)。離心泵是負(fù)容積泵，壓力相對(duì)較低。即使關(guān)閉排出閥，它也不會(huì)產(chǎn)生過(guò)高的壓力。14. In general, reciprocating pumps are suitable for delivering small quantities at highpressure, rotary pumps are used for moderate quantities at moderate pressure, andcentrifugal pumps are more suitable for la

25、rge quantities at low pressure. Centrifugalpumps, however, can be designed with a number of impellers in series to attain a highfinal delivery pressure. They are popular because they are very simple in construction,and can produce smooth, con sta nt, non pulsati ng discharge.通常，往復(fù)泵適于高壓下輸送少量液體，回轉(zhuǎn)泵適于中

26、等壓力下輸送中等數(shù)量的液體。離心泵則更適合于低壓下輸送大量液體。 然而離心泵可設(shè)計(jì)成若干葉輪串聯(lián)的形式，以獲得較高的最終輸出壓力。它們因構(gòu)造簡(jiǎn)單，并能產(chǎn)生平穩(wěn)、連續(xù)、無(wú)脈動(dòng)的流量而被普遍使用。B. Multiple Choice選擇題Questio ns 1-5 are based on paragraphs 1-2艮據(jù)課文第 1-21-2 段回答問(wèn)題 1-51-5。1. A pump may simply provide the liquid with an in crease in en ergy en abli ng it toflow or build up a pressure. W

27、hat does“it”in the sentence above refer to?簡(jiǎn)單地說(shuō)，泵給它提供能量從而使它能夠流動(dòng)或者建立一定的壓力。這里的它”指的是什么液體？答案: :B BA. A pump.泵B. The liquid .液體C. En ergy.能量D. An in crease .增量2. A vane pump bel ongs to_ accordi ng to its work ing prin ciple.根據(jù)工作原理，葉片泵屬于 _ _。答案.C.CA. reciprocat ing pump往復(fù)泵B. cen trifugal pump離心泵C. positi

28、ve displaceme nt pump正 容積泵D. cen tripetal pump向心泵3. A screw pump bel ongs to_accord ing to its work ing prin ciple.根據(jù)工作原理，螺桿泵屬于 _ _。答案.B.BA. reciprocat ing pump .往復(fù)泵B. positive displaceme nt pump正容積泵精品文檔精品文檔C. cen trifugal pump離心泵D. cen tripetal pump向心泵4. The pumps employed on board the ship can be

29、divided into two main categories i. e.pumps and cen trifugal pumps.船用泵可以分為兩種主要類型，例如泵和離心泵。答案.C.CA. gear齒輪B. non positive displaceme nt負(fù)容積C. positive displaceme nt正容積D. rotary回轉(zhuǎn)5. Gear pumps are positive displaceme nt type because they discharge a n ear con sta ntamount of liquid_pressure.5.齒輪泵是正容積泵，因

30、為它與壓力 _ _，排出幾乎恒定量的液體。答案;C;CA. depending upon依賴于（A A 項(xiàng)譯為：因?yàn)樗蕾囉趬毫Γ〣. in relative to有關(guān)C. regardless of無(wú)關(guān)D. axial-flow軸流Questions 6-9 are based on paragraphs 3-9艮據(jù)課文第 3-93-9 段回答問(wèn)題 6 6 -9.-9.6. The displaceme nt pump ing actio n is achieved by the reduct ion or in crease in causing the liquid （or gas） t

31、o be physically moved.容積泵通過(guò)泵腔的增減實(shí)現(xiàn)液體（或氣體）的移動(dòng)（吸排）。答案 D DA. flow amount of a liquid液體流量B. power of the pump泵功率C. area of a spacer作面積D. volume of a spacer作容積7. A relief valve is always fitted between the reciprocating pump suction anddischarge chambers to protect the pump_ with a valve closed in the di

32、schargeline.安全閥通常裝在往復(fù)泵的吸入腔和排出腔間，排出管上的閥關(guān)閉以保護(hù)泵。答案：A AA. should it be operated泵工作時(shí)B. it should be operated泵被操作時(shí)C. if it will be operated如果泵將被操作D. will it be operated泵將被操作時(shí)8. When staring the reciprocating displacement pumps, it is important that_ ,otherwise either the relief valve will lift or damage m

33、ay occur to the pumps when it isstarted.當(dāng)啟動(dòng)往復(fù)容積泵時(shí)，很重要，否則安全閥會(huì)開啟或者可能會(huì)對(duì)泵造成損害。答案: :B BA. a valve in the discharge line is closed出管路上一個(gè)閥關(guān)閉B. no valves in the discharge line are close（排出管路上沒有閥關(guān)閉C. some of the valves in the discharge line are ope ne排 出管路上一些閥打開D. none of the valves in the discharge line are

34、 ope ne排出管路上的閥都關(guān)閉9. The starting procedure of_ is similar to that for the reciprocatingdisplaceme nt pump.精品文檔精品文檔的啟動(dòng)過(guò)程與往復(fù)容積泵的過(guò)程相似。答案A. rotary displaceme nt pumps回轉(zhuǎn)容積泵B. cen trifugal pumps離心泵C. impeller pumps葉輪泵D. axial flow pumps軸流泵Questions 10-12 are based on paragraphs 10-1根據(jù)課文第 10-1210-12 段回答問(wèn)題

35、10-1210-12。10. The pump ing eleme nt for a vertical, sin gle stage, sin gle en try, cen trifugal pumpcon sists of_ .單級(jí)、單側(cè)吸入直立式離心泵泵送元件由一組成。答案A AA. a top cover, a pump shaft, an impeller, beari ng bush and a seali ng arra ngeme nt端蓋（頂蓋）、泵軸、葉輪、軸承套和密圭寸裝置B a cas ing, a pump shaft, a vane, a beari ng bush

36、 and a seali ng arran geme nt外殼、泵軸、葉片、軸承套和密封裝置C. a top cover, a screw, an impeller, bearing bush and a sealing arrangement端蓋、螺桿、葉輪、軸承套和密圭寸裝置D. a casing, a rotor, a propeller, a bearing bush and a sealing arrangement外殼、轉(zhuǎn)子、螺旋槳、軸承套和密封裝置11. Common faults with centrifugal pumps, such as no discharge, may

37、 be a result_of離心泵的通常故障，如沒有排放，可能是_ _的結(jié)果。答案.C.CA. valves in the system being shut系 統(tǒng)閥被關(guān)閉B. suct ion strai ners blocked吸入濾器堵塞C. either A or BA A 或 B BD. neither A nor B既不是 A A 也不是 B B12. Which feature of a centrifugal pump reduces the need for renewing worn impellersand pump cas in gs?離心泵的哪個(gè)特點(diǎn)減少了更新磨損的

38、葉輪和泵殼的必要？答案.D.DA. Close radial clearanee between impeller hub and casing.葉輪輪轂和殼體間徑向間 隙小。B. Low rotational speed of impeller.葉輪轉(zhuǎn)速低C. Removable end plate.可移動(dòng)端板。D. Replaceable impeller and cas ing wear rin gs可替換的葉輪和殼體承磨環(huán)。Questio ns 13-15 are based on paragraphs 13-1根據(jù)課文第 13-1413-14 段回答問(wèn)題 13-1513-15。13.

39、 Which of the follow ing will be the adva ntage of a cen trifugal pump as compared witha reciprocating pump?Its discharge is continuousIt has no internal valves;Upon accide ntal clos ing of discharge valve, excessive pressure will not build up與往復(fù)泵相比，下列哪些是離心泵的優(yōu)點(diǎn)？答案；A A它的排出是連續(xù)的；它沒有內(nèi)閥；排出閥意外關(guān)閉，不會(huì)形成過(guò)壓A.B

40、.C.D.only14. In general,_ is suitable for delivering small quantities at high pressure.通常來(lái)說(shuō)，更適合高壓下輸送少量液體。答案.A.A;A;A精品文檔精品文檔A. a reciprocat ing pump往復(fù)泵B. a gear pump齒輪泵C. a commi ngle pump混合泵D. a vane pump葉片泵15._are more suitable for large qua ntities at low pressure.適合于低壓下輸送大量液體。答案：c cA. Reciprocat ing pumps往復(fù)泵B. Rotary pumps回轉(zhuǎn)泵C. Cen trifugal pumps離心泵D. Gear pumps齒輪泵Task 2 V）cabulary and Structure任務(wù) 2