lesson 12 centrifugal pumps...

离心泵工艺流程简图英文回答：Centrifugal pumps are commonly used in various industrial processes to transport fluids. The process flow of a centrifugal pump can be summarized as follows:1. Suction: The pump is connected to the source of the fluid, such as a tank or a reservoir, through a suction pipe. The fluid is drawn into the pump through the suction inlet.2. Impeller: Inside the pump, there is a rotating component called the impeller. The impeller consists of curved blades or vanes that rotate rapidly when the pump is in operation. The impeller is responsible for imparting kinetic energy to the fluid.3. Centrifugal force: As the impeller rotates, it creates a centrifugal force that pushes the fluid away fromthe center of rotation. This centrifugal force increases the fluid's velocity and pressure.4. Discharge: The fluid exits the pump through a discharge pipe connected to the pump's outlet. The increased pressure and velocity of the fluid allow it to be transported to the desired location.5. Control: The flow rate and pressure of the pump can be controlled by adjusting the speed of the impeller or by using valves and throttling devices in the piping system.Example: Let's say I work in a chemical plant, and we use centrifugal pumps to transfer chemicals from storage tanks to various reactors. The process starts by connecting the suction pipe of the pump to the tank containing the chemical. The impeller inside the pump rotates rapidly, creating a centrifugal force that pushes the chemical towards the outlet. The chemical then exits the pump through a discharge pipe and is transported to the desired reactor. We can control the flow rate and pressure by adjusting the speed of the impeller or by using valves inthe piping system.中文回答：离心泵是工业流程中常用的输送流体的设备。

离心泵的工作原理及主要部件性能参数离心泵——生产中应用最为广泛，着重介绍。

§ 2.1.1 离心泵 （Centrifugal Pumps ） 一． 离心泵的工作原理及主要部件 1．工作原理如左图所示，离心泵体内的叶轮固定在泵轴上，叶轮上有若干弯曲的叶片，泵轴在外力带动下旋转，叶轮同时旋转，泵壳中央的吸入口与吸入管相连接，侧旁的排出口和排出管路9相连接。

启动前，须灌液，即向壳体内灌满被输送的液体。

启动电机后，泵轴带动叶轮一起旋转，充满叶片之间的液体也随着旋转，在惯性离心力的作用下液体从叶轮中心被抛向外缘的过程中便获得了能量，使叶轮外缘的液体静压强提高，同时也增大了流速，一般可达15～25m/s 。

液体离开叶轮进入泵壳后，由于泵壳中流道逐渐加宽，液体的流速逐渐降低，又将一部分动能转变为静压能，使泵出口处液体的压强进一步提高。

液体以较高的压强，从泵的排出口进入排出管路，输送至所需的场所。

当泵内液体从叶轮中心被抛向外缘时，在中心处形成了低压区，由于贮槽内液面上方的压强大于泵吸入口处的压强，在此压差的作用下，液体便经吸入管路连续地被吸入泵内，以补充被排出的液体，只要叶轮不停的转动，液体便不断的被吸入和排出。

泵离心泵旋转泵漩涡泵 往复泵由此可见，离心泵之所以能输送液体，主要是依靠高速旋转的叶轮，液体在离心力的作用下获得了能量以提高压强。

气缚现象：不灌液，则泵体内存有空气，由于ρ空气<<ρ液，所以产生的离心力很小，因而叶轮中心处所形成的低压不足以将贮槽内的液体吸入泵内，达不到输液目的。

通常在吸入管路的进口处装有一单向底阀，以截留灌入泵体内的液体。

另外，在单向阀下面装有滤网，其作用是拦阻液体中的固体物质被吸入而堵塞管道和泵壳。

启动与停泵：灌液完毕后，此时应关闭出口阀后启动泵，这时所需的泵的轴功率最小，启动电流较小，以保护电机。

启动后渐渐开启出口阀。

停泵前，要先关闭出口阀后再停机，这样可避免排出管内的水柱倒冲泵壳内叶轮，叶片，以延长泵的使用寿命。

水泵英语单词-回复Water PumpA water pump is a mechanical device used to move water from one place to another. It plays a crucial role in various industries and settings, including agriculture, construction, and household applications. In this article, we will explore the different types of water pumps, their functions, and how they work.The primary function of a water pump is to create a pressure difference that allows water to flow. Water pumps come in various types, including centrifugal pumps, reciprocating pumps, and submersible pumps. Each type has its unique features and applications.Centrifugal pumps are the most common type of water pump. They work by converting rotational energy from a motor into fluid energy, which creates a flow of water. Centrifugal pumps consist of several components, including an impeller, casing, and motor. The impeller is a rotating device that pushes the water towards the outlet of the pump, while the casing provides a confined space for the water to pass through. The motor is responsible for providingthe rotational energy needed to operate the pump.Reciprocating pumps, also known as piston pumps, use a piston or plunger to create pressure and move water. These pumps rely on the reciprocating motion of the piston to draw water into a cylinder and then force it out through a discharge valve. Reciprocating pumps are commonly used in high-pressure applications where a strong flow of water is required.Submersible pumps, as the name suggests, are designed to be submerged in water. These pumps are typically used for deep wells or in applications where water needs to be lifted from a lower level. Submersible pumps consist of a motor and an impeller enclosed in a waterproof casing. The motor powers the impeller, which generates the pressure needed to push water to the surface.Now that we have covered the different types of water pumps let's delve into their working principles. Starting with centrifugal pumps, the process begins with the motor spinning the impeller. As the impeller rotates, it creates a centrifugal force that pushes the water from the center towards the outer edges of the impeller. This action generates kinetic energy, which is then converted into pressureenergy as the water flows through the casing. Finally, the water is forced out through the pump's outlet.Reciprocating pumps work by using the motion of a piston or plunger. When the piston moves in one direction, it creates alow-pressure area that allows water to enter the cylinder through an inlet valve. As the piston moves back in the opposite direction, the inlet valve closes, and the outlet valve opens, forcing the water to flow out through the discharge valve. This reciprocating motion is repeated continuously, creating a constant flow of water.Submersible pumps operate by utilizing the principles of centrifugal force. The motor spins the impeller, which then pulls water into the casing. As the impeller spins faster, the water is forced towards the surface through the casing, creating the desired flow.In conclusion, water pumps are vital devices that enable the movement of water in various industries and settings. They come in different types, including centrifugal, reciprocating, and submersible pumps, each with its unique functions and workingprinciples. Understanding the different types and how they work can help individuals choose the right water pump for their specific needs.。

华东理工大学过程装备与系统（双语）Chapter 1 Introduction to Process EquipmentKey TermsAxial bearings轴向轴承: devices designed to prevent back-and-forth movement of a shaft; also called thrust bearings.Boiler锅炉: a type of fired furnace used to boil water and produce steam; also known as a steam generator. Compressors 压缩机: mechanical devices designed to accelerate or compress gases; classified as positive displacement or dynamic.Coupling联轴器: a device that attaches the drive shaft of a motor or steam turbine to a pump, compressor, or generator.Driver: a device designed to provide rotational energy to driven equipment.Heat exchanger换热器: an energy-transfer device designed to transfer energy in form of heat from a hotter fluid to a cooler fluid without physical contact between the two fluids.Pumps泵: devices designed to move liquids from one place to another; classified as positive displacement or dynamic.Reactor反应器: a device used to combine raw materials, heat, pressure, and catalysts in the right proportions to form chemical bonds that create new products.Steam turbine蒸汽轮机: an energy-conversion device that converts steam energy(kinetic energy) to useful mechanical energy; used as drivers to turn pumps, compressors, and electric generators.Valve阀: a device used to stop, start, restrict(throttle), or direct the flow of fluids.Questions:1.Identify the purpose of a steam turbineThe purpose of a steam turbine is to converts kinetic energy to useful mechanical energy in order to drive pumps, compressors, and electric generators. (P9)2.Describe the importance of equipment lubrication.Lubrication protects the moving parts of equipment, helps remove heat generated and provides a fluid barrier between the metals parts to reduce friction, thus ensuring the good operation of process equipment. (P10)3.Explain the purpose of bearings and seals.Bearings prevent up-and-down and side-to-side or back-and-forth movement of a rotating shaft.Seals prevent leakage between internal compartments in a rotating piece of equipment. (P10)Rotary equipment uses seals and bearings to maintain operation integrity. (P20)4.What is the difference between rotary and stationary equipment?Rotary equipment is characterized by a circular movement and is composed of a driver, a connector, and the driven equipment. (P4)However, stationary equipment is static. (自己编的)5.How is power transmission in rotary equipment classified?Power transmission in rotary equipment is classified as speed-to-torque conversion or torque-to-speed conversion. (P6) Chapter 2 ValvesKey TermsCheck valves止回阀: mechanical valves that prevent reverse flow in piping.Control valves: automated valves used to regulate and throttle flow; typically provide the final control element of acontrol loop.Disc阀瓣: a device made of metal or ceramic that fits snugly in the seat of a valve to control flow.Gate valve闸阀: a device that places a movable metal gate in the path of a process flow.Globe valve止通阀: a device that places a disc in the path of a process flow.Safety/relief valve安全/释放阀: device set to a automatically relieve pressure in a closed system at apredetermined set point; relief valve valves are used for liquids; safety valves are used for gases. Stuffing box填料函: the section of a valve that contains packing.Throttling节流: reducing or regulating flow below the maximum output of a valve.Trim: the flow-control element and seats in a valve.Questions:6.Explain the purpose of valves in industrial manufacturing.The primary purpose of a valve is to direct and control the flow of fluids by starting, stopping, and throttling (restricting) flow to make processing possible. (P25)7.Identify the basic components of a gate valve.P27 Figure 2.28.List the main types of valves.Gate valves. Globe valves. Ball valves. Check valves. Butterfly valves. Plug valves. Diaphragm valves.Relief and safety valves. Automatic valves./doc/b718128130.html,pare a relief valve to a safety valve.Relief valve valves are used for liquids; safety valves are used for gases.10.List the four types of check valves.Swing check valve. Lift check valve. Ball check valve. Stop check valve.Chapter 3 Tanks, Piping, and VesselsKey TermsAlloy合金: a material composed of two or more metals or a metal and a nonmetal.Blind盲板: a device used in piping to gain complete shutoff.Butt-weld piping: pipe on which the parts to be joined are the same diameter and simply welded together. Corrosion腐蚀: electrochemical reactions between metal surfaces and fluids that result in the gradual wearing away of the metal.Flanges法兰: used to connect piping to equipment or where piping may have to be disconnected; consist of two mating plates fastened with bolts to compress a gasket between.Floating-roof tank: has an open top and a pan-like structure that floats on top of the liquid and moves up and down inside the tank with each change in liquid level.Grounding: is described as procedure designed to connect and object to the earth with a copper wire and a grounding rod.Radiographic inspection: use of X-rays to locate defects in metals in much the same manner as an X-ray is taken of a broken bone.Socket-welded piping: type of piping in which the pipe is inserted into a larger fitting before being welded to another part.Tank farm罐区: a collection of tanks used to store and transport raw materials and products. Questions:11.List the different types of aboveground storage found ina tank farm.Low, medium, high pressure. (P51)12.What two types of blinds do we use?Paddle blinds and figure-eight blinds. (P64)13.How does increased temperature affect the performance of metals?In general, as temperature increases, the strength of metals decreases and corrosion rate increases. (P66) 14.What is an alloy steel?Steel that contains alloy elements is called alloy steel. (自己编的)15.What is corrosion, and how is it manifested?Corrosion is electrochemical reactions between metal surfaces and fluids that result in the gradual wearing away of the metal (定义). In a word, corrosion is metal loss. (P60)Corrosion attack manifests itself in many ways, such as general loss of metal, pitting, grooving, cracking, or other kinds of selective attack. (P60)Chapter 4 PumpsKey TermsCentrifugal pumps离心泵: a dynamic pump that accelerates fluid in a circular motion.Impeller叶轮: a device attached to the shaft of a centrifugal pump that imparts velocity and pressure to a liquid.Positive displacement正位移、容积式: class of equipment such as pumps and compressors that move specific amounts of fluid from one place to another; can be rotary or reciprocating.Priming灌液: becoming filled with fluid.Pulsation dampener缓冲器: a device installed close to a pump, in the suction or discharge line, to reduce pressure variations.Reciprocating pump往复泵: a positive displacement pumpthat uses a plunger, piston, or diaphragm moving in a back-and-forth motion to physically displace a specific amount of fluid in a chamber.Rotary pump回转泵: a positive displacement pump that uses rotating elements to move fluids.Slip泄漏: the percentage of fluid that leaks or slips past the internal clearance of a pump over a given time. Vapor lock气缚: condition in which a pump loses liquid prime and the impellers rotate in vapor. Questions:16.Describe the scientific principles associated with centrifugal pump operation and identify keycomponents.P8917.List the various types of rotary pumps.Screw pump, external gear, internal gear, sliding vane, flexible vane, lobe pumps.18.List the various types of reciprocating pumps.Piston, plunger, diaphragm.19.What are the advantages of centrifugal pumps?Centrifugal pumps are cheaper and require less maintenance and space.They will operate with a constant head pressure over a wide capacity range.It is easier to change the element on a centrifugal pump than on a PD pump, and it is easier to change the driver.A final advantage is the adaptability of the selected driver----variable horsepower and fixed or variablespeed. (P92)Chapter 5 CompressorsKey TermsAftercooler后冷却器: a heat-exchange device designed to remove excess heat from the discharge side of a multistage compressor.Compression ratio: the ratio of discharge pressure(psia) to suction pressure(psia). Multistage compressors use a compression ratio in the 3 to 4 range, with the same approximate compression ratio in rach stage. Demister除雾器: a cyclone-type device used to swirl and remove moisture from a gas.Dryer: removes moisture from gas.Lobe compressor罗茨压缩机: a rotary compressor that contains kidney bean-shaped impellers.Oil separator: removes oil from compressed gases.Stage: each cylinder in a compressor; specifically, the area where gas is compressed.Questions:20.List the two types of compressors.Dynamic, positive displacement, thermal.21.List the three rotary compressors.Rotary screw, lobe compressor, liquid ring, sliding vane, scroll.22.List the basic components of a centrifugal compressor. P12123.List the main difference between a single-stage and a multistage compressor.Single-stage compressors compress the gas once, whereas multistage compressors deliver the discharge of one stage to the suction of another stage. Single-stage compressors are designed for high gas flow rates and low discharge pressures; multistage compressors are designed for high gas flow rates and high discharge pressures. (P121)24.What is the difference between dynamic and positivedisplacement compressors?Dynamic compressors operate by accelerating the gas and converting the energy to pressure. They can deliver much higher flow rates than PD compressors. Positive displacement compressors operate by trapping a specific amount of gas and forcing it into a smaller volume. (P140)Chapter 7 Heat ExchangersKey TermsCondenser冷凝器: a shell-and-tube heat exchanger used to cool and condense hot vapors.Conduction传导: the means of heat transfer through a solid, nonporous material resulting from molecular vibration. Conduction can also occur between closely packed molecules.Convection对流: the means of heat transfer in fluids resulting from currenst.Counterflow逆流: refers to the movement of two flow streams in opposite directions; also called countercurrent flow.Fixed head固定头: a term applied to a shell-and-tube heat exchanger that has the tube sheet firmly attached to the shell.Laminar flow层流: streamline flow that is more or less unbroken; layers of liquid flowing in a parallel path. Radiant heat transfer辐射传热: conveyance of heat by electromagnetic waves from a source to receivers. Reboiler再沸器: a heat exchanger used to add heat to a liquid that was once boiling until the liquid boils again.Shell-and-tube heat exchange管壳式换热器: a heat exchanger that has a cylindrical shell surrounding a tube bundle.Turbulent flow湍流: random movement or mixing in swirls and eddies of a fluid.Questions:25.What is a heat exchanger?A heat exchanger is an energy-transfer device designed to transfer energy in form of heat from a hotterfluid to a cooler fluid without physical contact between the two fluids. (第一章)26.What is meant by the term floating head?Floating head heat exchangers are designed for high temperature differentials above 200℉(93.33℃).During operation, one tube is fixed and the other “floats”inside the shell. The floating end is not attached to the shell and is free to expand. (P163)27.List five types of heat exchangers.Pipe coil exchangers, double-pipe heat exchangers, shell-and-tube heat exchangers, reboilers, plate-and-frame heat exchangers, air-cooled heat exchangers, spiral heat exchangers.28.Explain the purpose of using finned tubes in heat exchangers.Fins provide more surface area and allow greater heat transfer to take place. (P172)29.Contrast parallel and series flow through a heat exchanger.In series flow, the tube-side flow in a multipass heat exchanger is discharged into the tube-side flow of the second exchanger. This discharge route could be switched to shell side or tube side depending on how the exchanger is in service. The principle is that the flow passes through one exchanger before it goes to another. In parallel flow, the process flow goes through multiple exchangers at the same time.(P167)Chapter 8 Cooling TowersKey TermsAir intake louvers进风口: slats located at the bottom or sides of a cooling tower to direct airflow.Basin水池/槽: concrete storage compartment or catch basin located at the bottom of the cooling tower. Blowdown排污/清洗: a process of controlling the level of suspected solids in a cooling tower by removing a certain amount of water from the basin and replacing it with makeup water.Capacity可冷却的水量: the amount of water a cooling tower can cool.Cooling towers冷却塔: are evaporative coolers specifically designed to cool water or other mediums to the ambient wet-bulb air temperature.Drift eliminators收水器: devices used in a cooling tower to keep water from blowing out.Evaporate蒸发: to turn to vapor; evaporation removes heat energy from hot water.Forced-draft强制通风: type of mechanical-draft cooling tower that uses fans to push air into the tower. Induced-draft诱导通风: type of mechanical-draft cooling tower that uses fans to push air out of the tower. Questions:30.List and describe the basic components of a cooling tower.Water distribution header, splash bars, fill, basin, cooling water supply header, process exchangers, cooling water return header, drift eliminator. (P195自己看着抽出来的)31.Describe the relationship between heat exchangers and a cooling tower.In the manufacturing environment, heat exchangers and cooling towers work hand in hand to create a water-cooling system. Balabala… (P200)32.List five factors that affect the efficiency of a cooling tower.Evaporation, relative humidity, temperature, wind velocity, tower design, water contamination. (P194) 33.Which tower is most efficient: forced-draft or induced-draft? Why?Induced-draft. In an induced-draft cooling tower, the tower fan, located on the top of the tower, produces discharge rates strong enough to lift the hot air above the tower, so hot air is not recirculated into the tower. However, in a forced-draft cooling tower, the exiting air slows so much that it is recirculated back into the tower, cutting efficiency by 20%. (P198, 199)。

中国石油大学（北京）远程教育学院期末考试卷油气储运工程英语》复习资料答案一、填空1、 ___ are solid compounds that form as crystals and resemble snow in appearance考生答案： Hydrates2、 Natural gas with H2S or other sulfur ___ present is called “ _____考生答案： compounds3、 Most oil and gas pipelines fall into one of three groups: ___ , ______ , or _____ .考生答案： gathering trunk/transmission/distribution4、 All ____ t anks have a cover that floats on the surface of the liquid考生答案： floating-roof5、 Natural gas ____ is highly dependent on weather.考生答案： demand6、 Energy is supplied to the liquid through the pump by the pump ' sd river -anor an electric _____ .考生答案： engine/urbine/motor7、 To form a stable emulsion of crude oil and _____________ ,an emulsifying _______ must考生答案： water/agent8、 Most pipelines are coated on the exterior to prevent ____ .考生答案： corrosion9、 Natural gas with only CO2 is called “ ________ g as ”.考生答案： sweet10、 The hydrocarbons contain only ___ and _____ .考生答案： carbon / hydrogen11、 Centrifugal pump consists of an ___ and a ____ .考生答案： impeller/ casing12、 The distance between compressors varies, depending on the _____________ of gas,and other factors.考生答案： volume/ size课程编号：gas a _____ be present. the line ______13、In designing a pipeline system, the ____________ of pump stations must be determined as wellas ____ of individual pumps within each station.考生答案：location/size14、The type of information gathered by smart pigs includes the pipeline _________________ , curvature, bends, temperature and _____ , as well as ____ or metal loss.考生答案：diameter pressure/corrosion15、____ is short for American Petroleum Institute.考生答案：API16、The two categories of floating-roof tanks are _______________ floating roof and ____________ f loating roof.考生答案：external/internal17、Gas is moved through a gas pipeline by ___ .考生答案：compressors18、____ i s always necessary for hydrate formation.考生答案：Water19、The pressure in the pipeline decreases due to ___ and ______ losses.考生答案：friction /elevation20、Most pipelines are tested with water ( ____________ testing) either in sections or over theentire _____ .考生答案：hydrostati/length21、The position of ____ and the extent of mixing can be monitored at points along theline by measuring the ____ of the fluid in the line.考生答案：batch /density22、All pipelines are tested for ____________ following ____ before the line is put into service.考生答案：leaks/ construction23、Well fluids are often a complex mixture of ___ ,gas,and some ______ ．考生答案：liquid hydrocarbons <mpuritie24、The individual phases (gas, ________ , ______ , and solids) should be separated from each other as early as practical.考生答案：liquid hydrocarbon /liquid water25、Launcher (at the end of a station to launch _______________ t o downstream station) is requiredat the _____ of the section.考生答案：pig/ upstream26、An emulsion is a combination of __________ ,or liquids that do not mix together under normal conditions ．27、Products pipeline often must operate at ______________ pressure than crude pipelines becausethe material being transported is _____ than crude.考生答案：higher lighter28、Shipping emulsified oil wastes costly ___ occupied by valueless water.考生答案：transportation capacities29、When no physical barrier is used between different products in products pipeline,the _____ of the two materials maintains the separation.考生答案：difference in density30、Reciprocating compressor unit includes ____ and _____ .考生答案：compressor driver compressor31、Two general types of line pipe are manufactured: ____ and _____ .考生答案：seamless welded32、In pumping any liquid, the goal is to add energy to the liquid to cause it to movethrough a pipeline by overcoming the _____ and changes in _____ .考生答案：friction elevation33、The ____ of the substance stored determines the shape and type of tank.考生答案：vapor pressure34、Standing storage losses result from evaporative losses through ___________________ ,______ , and/or deck seam.考生答案：rim seals deck fitting35、There is 8~12in gap between the __________ and _______ , so the floating roof does not bindas it moves up and down with the liquid level.36、Many crude storage tanks are equipped with ____ that capture light hydrocarbonsthat evaporate from the crude and would otherwise be lost to the atmosphere.考生答案：vapor recovery systems37、Many different corrosion ___ and ______ of corrosion can be at work on the sametank at the same time.考生答案：mechanisms38、Mass-flow meters directly measure the mass of the fluid passing through the meter,no intermediate temperature or pressure ______________ are required and __________ is about the same as PD or turbine meters.考生答案：measurements39、Most pipelines are constructed by ___ short lengths or _____ of pipe together考生答案：welding joints40、NGL is short for ___ .考生答案：atural Liquids41、ESD is short for ___ .考生答案：emergency shutdown42、LNG is short for ___ .考生答案：Liquefied atural43、EFR is short for ___ .考生答案： E xternal F loating R Roof44、LACT unit is short for ___ .考生答案：ease automatic custody transfer unit45、IFR is short for ____ .考生答案：I nternal F loating Roof46、PD meters are short for ____ .考生答案：positive-displacement meters47、PV Valves is short for ___ .考生答案：pressure vacuum vent valves翻译题48、Oil-in-water emulsion考生答案：水包油乳状液49、Emulsion考生答案：乳状液50、Well fluids are often a complex mixture of liquid hydrocarbons,gas,and some impurities ．考生答案：井流通常是液态烃、气体和某些杂质的复杂混合物。

LL-54SPECIFICATIONSPort Size:Combination 11⁄2" female and 2"male NPT threaded suction and discharge portsMechanical Shaft Seal:Self-lubricating ceramic and carbon (siliconized graphite optional) faces with 316 SS case and spring Gaskets:EPDM standard; Viton ®and Buna-N (optional)Max. Temperature/Pressure:For all FPUCS100 Series pumps in all configurations, max. temp. is 93°C (200°F) at up to 32 psig max. pressureWetted Parts:Glass-reinforced Noryl ®body standard, glass-reinforced PPS optional; EPDM O-rings std., Viton ®and Buna-N opt.; 316 SS internals with self-lubricating carbon/ceramic mechanical seal with 316 SS case and springs std.; polypropylene basket strainer included with Noryl ®body unit, ECTFE basket strainer included with PPSbody unit; external hardware is 18-8 SS Net Positive Suction Head:4.6 m (15') after initial primingߜRe-Primes to 4.6 m (15')* ߜNoryl ®or PPS BodyߜFlow Rates to 110 U.S. GPM ߜPedestal Mounts Available* Based on water-like liquids at 21°C (70°F) and 60 Hz operation after initial priming of pump housing.For PPS body instead of Noryl ®, add suffix “-RY ” to part number and add $510 for close coupled units, $500for pedestal mount. For epoxy-coated cast iron pedestal-mounted pump head without motor, baseplate or couplings, add suffix “-PED ”. Price = $462for Noryl ®/316 SS (ship weight is 18 lb). To change EPDM to Buna-N or Viton ®O-rings, add suffix “-B ” or “-V ” to model number and add $138for Viton ®, no extra charge for Buna-N. For 50 Hz motor, please specify “- (Voltage)/(Phase)/50 Hz (consult OMEGA’s Flow Engineering Department for price).For 230/460, 3-phase, 60 Hz motor, add suffix “-243” and subtract $10from list price. To order an EPDM fitted hard-siliconized, graphite-faced shaft seal for abrasive applications, add suffix “-SC ” to model number and $214to price.Ordering Example:FPUCS101-RY , close coupled pump with 1.0 S.G., 60 GPM max flow, PPS body instead of Noryl ®, $623 + 510 = $1133.FPUCS100 Series cutaway view, shown smaller than actual size.FPUCS101$623The self-priming FPUCS100 Series pump is available with either Noryl ®or PPS body, providing a maximum range of chemical resistance. It also offers 316 SS internal hardware and comes standard with 18-8 SSexternal hardware. Protected with a basket-type strainer in eitherpolypropylene (with Noryl ®body) or ECTFE (with PPS body). The large cover makes initial priming and removal of the strainer quick and easy.The cover is of the same material as the pump. After initial priming, the pump will lift up to 4.6 m (15')vertically and will remain primed even after shutdown. Features include an open, non-clogging impeller that is molded inconjunction with the shaft sleeve,isolating the shaft from solution contact. This is an ideal chemical transfer, waste-treatment,SELF-PRIMING CENTRIFUGAL PUMPSFor Transfer and RecirculationCANADA www.omega.ca Laval(Quebec) 1-800-TC-OMEGA UNITED KINGDOM www. Manchester, England0800-488-488GERMANY www.omega.deDeckenpfronn, Germany************FRANCE www.omega.frGuyancourt, France088-466-342BENELUX www.omega.nl Amstelveen, NL 0800-099-33-44UNITED STATES 1-800-TC-OMEGA Stamford, CT.CZECH REPUBLIC www.omegaeng.cz Karviná, Czech Republic596-311-899TemperatureCalibrators, Connectors, General Test and MeasurementInstruments, Glass Bulb Thermometers, Handheld Instruments for Temperature Measurement, Ice Point References,Indicating Labels, Crayons, Cements and Lacquers, Infrared Temperature Measurement Instruments, Recorders Relative Humidity Measurement Instruments, RTD Probes, Elements and Assemblies, Temperature & Process Meters, Timers and Counters, Temperature and Process Controllers and Power Switching Devices, Thermistor Elements, Probes andAssemblies,Thermocouples Thermowells and Head and Well Assemblies, Transmitters, WirePressure, Strain and ForceDisplacement Transducers, Dynamic Measurement Force Sensors, Instrumentation for Pressure and Strain Measurements, Load Cells, Pressure Gauges, PressureReference Section, Pressure Switches, Pressure Transducers, Proximity Transducers, Regulators,Strain Gages, Torque Transducers, ValvespH and ConductivityConductivity Instrumentation, Dissolved OxygenInstrumentation, Environmental Instrumentation, pH Electrodes and Instruments, Water and Soil Analysis InstrumentationHeatersBand Heaters, Cartridge Heaters, Circulation Heaters, Comfort Heaters, Controllers, Meters and SwitchingDevices, Flexible Heaters, General Test and Measurement Instruments, Heater Hook-up Wire, Heating Cable Systems, Immersion Heaters, Process Air and Duct, Heaters, Radiant Heaters, Strip Heaters, Tubular HeatersFlow and LevelAir Velocity Indicators, Doppler Flowmeters, LevelMeasurement, Magnetic Flowmeters, Mass Flowmeters,Pitot Tubes, Pumps, Rotameters, Turbine and Paddle Wheel Flowmeters, Ultrasonic Flowmeters, Valves, Variable Area Flowmeters, Vortex Shedding FlowmetersData AcquisitionAuto-Dialers and Alarm Monitoring Systems, Communication Products and Converters, Data Acquisition and Analysis Software, Data LoggersPlug-in Cards, Signal Conditioners, USB, RS232, RS485 and Parallel Port Data Acquisition Systems, Wireless Transmitters and Receivers。

附录(一):Optimizing centrifugal pump operationCentrifugal pump operation is more than switching the pump on and directing the discharge flow to the required delivery point. This holds true even when a control value is installed in the discharge line for the purpose of flow or level control .A few very essential operating guidelines must be adhered to if early bearing or seal failure, premature erosion of internal wetted surfaces, or metal-to-metal contact of internal rotating and stationary surfaces, is to be avoided. In this article, Stan Shiels addresses the fundamentals of proper centrifugal pump operation and the most common areas of improper centrifugal pump operation. It is assumed that the pump has been successfully commissioned.The most common cause of centrifugal pump failure, separate from those causes associated with maintenance and/or design, but associated with how the pumps are operated may be summarized as follows:1. Insufficient suction pressure to avoid cavitation.2. Excessively high flow rate for the net positive suction head available (NPSHA).3. Prolonged operation at lower than acceptable flow rates.4. Operation of the pump at zero or near zero flow rate.S. Improper operation of the pump in parallel.6. Failure to maintain adequate lubrication for the bearings.7. Failure to maintain satisfactory flushing to mechanical seals.Insufficient suction pressure to avoid cavitation.While the provision of sufficient suction pressure to avoid cavitation may seem straightforward, requiring only that the net positive suction head available(NPSHA) be always greater than or equal to the net positive suction head required (NPSHR) by the pump, some misconceptions need to be revealed. When the pump manufacturer develops the pump's NPSHR curve, the calculated values of NPSHR are for conditions where theexpected head (as determined by the previously performed pumphydraulic performance test) has fallen of by 3% for that specific flow rate. This means that mild cavitation will exist when the NPSHA equals the NPSHR. Because of this a comfort margin of 3 feet, or 1meter, isrecommended, when determining the minimum acceptable NPSH margin:(NPSHA-NPSHR).The following piping faults will require an NPSH margin greater than 3 feet(1 meter) to ensure the absence of cavitation.~Where the inlet piping configuration is such that a number of 90 degree turns occur, in different planes, fairly close to the pump suction, the resultant fluid swirl will cause cavitation to occur, on occasion, even when the NPSH margin is 2 to 3 feet.~Where an eccentric inlet reducer is positioned in the pipe such that itforces asymmetric flow into the suction of a double suction pump. The side of the double suction impeller that receives the disproportionately higher percentage of the total flow will incur cavitation at an NPSHA much higher than the NPSHR indicated on the manufacturer's test curve.Excessively high flow rate for the NPSH availableBased upon the simple fact that NPSHA decreases as flow rate increases, and NPSHR increases as flow rate increases, there should be considerable effort place on ensuring that the point of intersection of these two parameters is not reached. This concept is illustrated in Figurel.Many centrifugal pumps are installed in a system, which cannot pro vide adequate suction pressure to avoid cavitation, if operated at flow rates much above their best efficiency point (BEP). It is probably never intended to operate these pumps in such a region, but transient conditions can often lead to intended operation at much higher than expected flow rates. One example is the case where a recycle control value has been installed to ensure that the pump is not operated below a minimum acceptable flow rate. At very low or zero process flow the recycle control value may attain a position of greater than 50% open. This of itself is not a problem, but the extremely high flow rate may occur when the process control value is again asked to open, and does so rather quickly. When the process control valve is faster acting than the recycle control valve, the combined process and recycle flows may necessitate a higher NPSHR than the suction system can provide.Manual operation must also be handled carefully when simple transfer operations between vessels is called for. At the start of such operation the receiving vessel may have a very high level. This leads to a negative static head, which can lead to an initial high flow rate until the level rises in the discharge vessel. This is a particularly risky operation where piping system resistance is low on the discharge side, but a relatively long section of suction piping exists.Prolonged operation at lower than acceptable flow ratesA centrifugal pump is most comfortable operating between 85% and 110% of its best efficiency point (BEP). However, by far the great majority of centrifugal pumps are forced to operate outside of this range. The degree to which it is acceptable to operate outside of this range is a function of two primary parameters:Suction Specific Speed (Ss) and Specific Speed (S). These parameters may be calculated for a pump provided the following data is known: For maximum diameter impeller:BEP FlowNPSHR at BEP FlowHead at BEP FlowPump Operating Speed (RPM)The following formulae allow Ss and S to be calculated:()0.50.750.50.75()()()bep bepbep bep SpecificSpeed S REP Q H SuctionSpecificSpeed Ss RPE Q NPSHR=⨯÷=⨯÷Where: QPM is pump rotational speed in revolutions per minute.bep Q flow at BEP for maximum diameter impeller.bep H is pump head at BEP for maximum diameter impeller.bep NPSHR is the pump net positive head required at BEP for maximum diameter impeller.The acceptable minimum continuous flow rate, which a centrifugal pump can be expected to endure without incurring damage or premature failure is also affected by a number of other parameters: such as, impeller head, fluid specific gravity , and percentage of total running time spent at the lower flow rate. When the pump's specific speed and suction specific speed are known the approximate percentage of the pump's maximum impeller diameter BEP flow at which suction recirculation can be expected to occur may be estimated.From this estimate the approximate minimum acceptable continuous flow rate for that specific pump may be estimated. Impeller geometry can be optimized to improve on initial estimates and, when conditions are marginal, it is always advisable to consult with the manufacturer's application engineer before deciding on the acceptable minimum continuous flow rate.A subsequent article can expend further on this much debated area of centrifugalpump operation. In the interim it is suggested that pump users request the minimum "stable" continuous flow rate recommended from the pump manufacturer, based upon the onset of flow instability .Impeller geometry can impact the "Cavitation Coefficient" which is defined by the following formula:211(2)u g NPSH u δ=⨯÷Where1u δ is the cavitation coefficientg is the gravitation constantNPSH is net positive suction head1u is fluid circumferential velocity at impeller entryThis is a dimensionless coefficient and would be valid for all geometrically similar pumps, independent of their size and speed of rotation.Operation of the pump at zero or near zero flow rateCentrifugal pumps are often used to pump out vessels, often to zero level. The pumps can, at times, be left unattended. If the level is allowed to fall to the point where the pump is allowed to run dry , failure of the mechanical seal will often follow rapidly. In such applications even a small recycle flow back to the suction vessel will not alleviate the problem, as the pump will still be able to empty the vessel. Many such applications are best protected by the installation of dual pressurized mechanical seals which will remain lubricated even during periods of completely dry running. In non hazardous applications a pump sealed with packing will survive better if the packing is lubricated from an external source; the source must, of course, be compatible with the fluid being pumped.Where batch delivery is normal operation, such that the pump will operate for long periods, but delivery is intermittent, a small continuous recycle flow back to the suction source will help to protect the pump during periods when delivery stops (typically by closing the delivery valve). Lack of some of the recycle protection for a centrifugal pump, which will see periods of zero flow, will certainly cause frequent pump failure. Any centrifugal pump operated at zero flow for even a few minutes will vapour temperature. It is worth remembering that once a pump has vapour-locked it will not generate any noticeable discharge pressure differential. Usually it is necessary to stop the pump and allow the gas to condense back into liquid, before pumping can resume.Improper operation of the pump in parallel.This topic has been covered in detail in a previous "Pump Academy" article, but the basics are worthy of mention in terms general centrifugal pump operating philosophy. The following principles should be applied to any operation of centrifugal pumps, which requires either continuous or intermittent parallel operation.~Shut-off heads of all pumps operating in parallel should be comparable typically as close as possible, with difference of no more than 2%or 3% recommended~V ery flat performance curves in one or more of the pumps operating in parallel is to be avoided;a drop of 10% to 20% between the shut-off and rated points is recommended. The point of hydraulic shut-off of the more worn pump of two initially identical pumps operating in parallel is shown in Figure 2, for high head rise to shut-off and low head rise to shut-off.~Multistage pumps, or expensive single-stage or two-stage pumps designed to operate in parallel, should be protected by low flow shut-down devices to avoid severe damage from occurring at transient low combined flow conditions. While the pumps may be identical, performance differences occur over time, and the better performing pump will effectively "shut-off" the weaker pump below a specific combined flow rate. The low flow shut-down will prevent the major damage that often results from such occurrences.~inlet and discharge piping configurations and lengths should be comparable between the pump and the suction and discharge headers. Proper piping configuration for pumps operating in parallel should include suction and discharge headers of larger diameter than the lines leading to and from the individual pumps. Differences in suction and/or discharge piping configuration will always lead to a disparity in pump flow rates.Failure to maintain adequate lubrication for the bearingsThis is a simple statement and sounds too fundamental to be ignored, but, even among those diligent pump operators who strive to maintain adequate lubrication, some inadvertent mistakes are made. Lubrication of rolling element bearings is the subject here. They may be oil lubricated or grease lubricated. The complete topic requires more attention than can be afforded in this text, but the basic essentials always hold true and can only be ignored at the risk of early pump failure.Oil lubrication is of three basic types: forced feed with a pressurized filtered and cooled oil supply to the bearings in a closed loop system; oil bath; and oil mistThe forced feed system is the most complicated and usually incorporates a low oil pressure shutdown protection; it is normally only present in large multistage pump installations. The key areas of concern are:~Maintenance of the correct viscosity of the oil and periodic monitoring for changes in viscosity and/or Total Acid Number (TAN) and the presence of water in the oil.~On occasion ferrographic analysis for the presence of wear particles helps to diagnose impendent bearing damage.~Lube oil cooler performance decline may lead to elevated temperatures and periodic oil temperature monitoring is also essential.~Oil filter differential pressure and main oil supply pressure to the bearings also requires frequent attention.A housing for oil bath lubrication normally incorporates a constant level oiler, although some pump users have chosen to seal their bearing housing and use synthetic oil, changing the oil only once every two or three years. For those bearing housings incorporating a constant level oiler the following basic principles apply:~Use of the correct viscosity oil for the operating temperature of the bearing (refer to the bearing manufacturer's literature).~Maintenance of a reserve of oil in the constant level oiler.~Clean storage of the make-up oil to prevent foreign material and/or moisture from entering the bearings.~Observance of the deterioration in the oiler level一remember, oilers whose level never falls over time may have a blocked connection between the oiler and the bearing housing.Oil mist lubrication requires that the same viscosity oil be used as for oil bath lubrication. On occasion a grade lighter oil may be used as the oil is being constantly replenished, although this approach should be taken with caution. While most oil mist systems incorporate an alarm for loss of oil mist pressure, each bearing housing should be periodically checked to confirm adequate venting of oil mist from the housing, and for proper condensation and drainage of bearing housing oil mist condensate collection pots.Grease lubrication of rolling element bearings requires proper attention to the following:~The type of grease used. A stiffer grease for higher speeds (3000 RPM and above) and a softer grease for lower speeds.~The grease should essentially contain the same viscosity of oil in it as that required for oil bath luibrication.~The amount of grease. This is of particular importance where pump operators are responsible for regreasing of bearings, as a major cause of failure of grease lubricated pump bearings is overgreasing. The idea that more is better is very wrong here.~Compatibility of greases. When regreasing it is essential that the grease to be added is compatible with the originally installed grease.As is the case for oil type selection, it is recommended that the bearing applications engineering department be consulted, when in doubt about which grease is best for each specific application.Failure to maintain satisfactory flushing to mechanical sealsThe flushing plan for a mechanical seal is the means of controlling the environment in which the seal operates. It follows then that any event that alters the intended flushing flow parameters will alter the seal's environment and may lead to seal failure. The following parameters, for some of the most commonly utilized seal flushing arrangements, should be regularly monitored for mechanical seals:Pump discharge flush to the seal to confirm that the temperature is correct. The dischargeflush should be at the same temperature as the pump discharge flow. In hot service a cooler flush will indicate lack of sufficient flow; this is often the only means available of checking flow, as most discharge flush plans do not have a flow indication.Suction flush from the seal cavity to the pump suction should also be checked for temperature. This may require that the temperature be checked initially to set a "benchmark." Any noticeable increase in this flush return to the pump suction may indicate a flow restriction.Cooled discharge flushes require adequate cooling to attain the required flush temperature. Discharge flush coolers foul over time and often the flush temperature is allowed to rise to the point of seal failure before cooler fouling is discovered. Both the cooling water differential temperature and the flush supply temperature to the seal should be monitored and the cooler replaced of cleaned before fouling progresses too far.Dual unpressurized seals rely on a head of liquid in a seal pot to provide a small pressure differential between the seal interspace and atmosphere. Both the seal pot level and the seal pot pressure should be observed for signs of change. Dualunpressurized seals are often utilized in volatile fluid service, where the vapour pressure is above atmospheric and any normal primary seal vapour leakage can be vented through the seal pot orifice to a safe collection point; a noticeable increase in seal pot pressure would indicate a primary (inner) seal failure. A reduction in seal pot level would indicate an outer seal failure.Dual pressurized seals incorporating a seal pot similarly should be monitored. The seal pot pressure must be maintained at a pressure above the seal cavity pressure for satisfactory seal operation. A reduction in seal pot level will indicate either a primary or or outer seal failure; further observation for obvious leakage of the outer seal is required to determine which one has failed. Loss of seal pot pressure may indicate a failure of the pressure blanketing system. Alarms are usually incorporated in dual seal systems incorporating seal pots. It is still advisable to monitor these parameters to allow early warning of loss of adequate seal flushing.Dual pressurized seals utilizing a flow-through barrier fluid system should have regular checks carried out for barrier fluid inlet and outlet temperatures and pressures. If the barrier fluid return pressure is allowed to drop to a value below the seal cavity (pump side) pressure, seal failure will follow in a pump media containing abrasives. Not all such systems have flow indication and a rise in differential temperature will usually indicate an increase in leakage rate of the inner seal, but could signify a reduction in barrier fluid flow rate; where flow rate is not subject to change it normally indicates an increase in inner seal leakage rate. A check of barrier fluid inlet pressure to the seal will assist in the diagnosis. A drop in barrier fluid return pressure, usually accompanied by arise in return temperature, is almost always associated with an inner seal failure.A last wordWhile there are many more causes of operational failure of centrifugal pumps, this discussion has dealt with the most frequently contributing areas. The operators of centrifugal pumps must extend their scope into the area of "ownership: Operators need to become familiar with tow these pumps operate, their key areas to monitor, and what to look for. It could also be said that many large process plants, which operate a large number of centrifugal pumps, do not provide sufficient pump training to permit the operating staff to understand key operating principles and satisfactory monitoring guidelines. We enjoy driving our automobiles. When have maintenance carried out: oil change, engine tune-up, transmission checked, brakes overhauled,tires renewed, fluid levels checked, hoses replaced, etc. most of us do not drive our cars until the oil breaks down completely and seizes the engine, the coolant hose blows, the brakes fail, the tires lose their tread, or the transmission fails. Periodic checks allow us to avoid such failures. We own our cars and do not want to incur the cost and inconvenience of such failures. A similar frame of mind toward centrifugal pump operation, supported by a proper program of operator training will pay dividends in terms of pump reliability and the cost of pump operation, and avoid some costly process debits.附录（二）：优化离心泵的操作操作离心泵不仅指打开水泵阀门、接通排水管、导出排放液体到规定传输点还包括在排水管中安装控制阀以控制调节流量和液位等为了避免早期轴承或密封失效、内部潮湿表面过早浸蚀、以及内部旋转和固定部分金属表面发生摩擦等状况发生，在操作离心泵时须遵循一定的操作原则, 本文中，Stan Shiels给出了离心泵合理操作的基本法则和不正确使用离心泵的常见误区本文假设离心泵正常投入运行。

Unit 21Pumps1. IntroductionPump, device used to raise, transfer, or compress liquids and gases. Four' general classes of pumps for liquids are described below t In all of them , steps are taken to prevent cavitation (the formation of a vacuull1), which would reduce the flow and damage the structure of the pump, - pumps used for gases and vapors are usually known as compressors . The study of fluids in motion is called fluid dynamics.1．介绍泵是提出，转移或压缩液体和气体的设备。

下面介绍四种类型的泵。

在所有的这些中，我们一步步采取措施防止气蚀，气蚀将减少流量并且破坏泵的结构。

用来处理气体和蒸汽的泵称为压缩机，研究流体的运动的科学成为流体动力学。

Water Pump, device lor moving water from one location to another, using tubes or other machinery. Water pumps operate under pressures ranging from a fraction of a pound to more than 10,000 pounds per square inch. Everyday examples of water pumps range from small electric pumps that circulate and aerate water in aquariums and fountains to sump pumps that remove 'Water from beneath the foundations of homes.水泵是用管子或其他机械把水从一个地方传到另一个地方。

11规则大连海事轮机英语最新题库翻译（八）作者：系统管理员来源：发布时间： [2014-04-02] 点击数： 486第2节船用泵词汇记忆：air cushion 气垫Bbalancing hole 平衡孔ballast 压载水bi-directional operation 双向操作bilge water 舱底水branch 支路，支管bursting discharge pressure破坏性排放压力Ccasing 泵壳cavitation 气蚀charge-over chest 转换阀箱clog 脏堵circuit breaker 回路断路器Ddeck scupper 甲板排水孔diffuser 扩压器discharge head 排放压头domestic water 日常用水Eeductor喷射泵ejector pump 喷射泵emergency bilge pump应急舱底水泵Ffeeler gauge塞尺/测隙规floating ring 浮环fluid 流体Gglobe valve 球阀Hheel 横倾helical pump螺旋泵hydro-pneumatic tank 液压气动柜Iidle 从动impeller 叶轮in series 串联in parallel 并联Kkinetic energy 动能Lleakage 泄漏Mmanufacturer 生产商mechanical energy 机械能mechanical seal 机械密封megger 兆欧表misalignment 未对中mono type 单螺杆式mud box 泥箱multistage 多级Nnegative suction head负吸入压头Ppack 填料（盘根）pitch 螺距potable water 饮用水potential energy 势能pressure energy 压力能prime 引液，灌注（-r引液装置）pulsation 脉动(non-无脉动)Rradial thrust 径向力regardless of 无关rotational ring 转环rotor 转子Ssaturation temperature 饱和温度scoring 划痕Sea chest 海底阀箱self-priming 自吸sleeve 轴套square 平方static suction lift 静吸入提升（压头）stationary ring静环steady 平稳，稳定stop-check valve 截止阀stuffing box 填料函suction head 吸入压头symmetrical impeller 对称叶轮Tthrottle 节流triple -screw pump 三螺杆泵Vviscosity 黏度Volume 体积Volute 涡壳Wwearing ring 承磨环考点一：泵的类型☐displacement pump 容积泵☐reciprocating pump 往复泵☐direct acting type直接作用式☐Power type动力驱动式☐crank-fly wheel type曲轴飞轮式☐rotary pump 回转泵☐Gear type齿轮式☐Vane type叶片式☐screw type螺杆式☐piston type柱塞式☐cam-and-piston type凸轮柱塞式☐Centrifugal离心泵☐Volute type涡壳式☐Diffuser type导轮式☐mixed-flow type混流式☐axial flow type轴流式☐turbine or regenerative type旋涡式2.2.1 船用泵类型1. A vane pump belongs to _____according to its working principleA. reciprocating pumpsB. positive displacement pumpsC. centrifugal pumpsD. centripetal pumps答案为B。

离心泵自吸装置原理Centrifugal pumps are widely used in various industries for fluid transportation and circulation. They are efficient and reliable, but they may have difficulty in self-priming, especially when the pump is located above the fluid level. 离心泵在各行各业中广泛应用于流体运输和循环。

它们高效可靠，但在自吸方面可能存在困难，尤其是当泵位于流体水平以上时。

The self-priming mechanism of a centrifugal pump involves using a vacuum or air pressure to create a siphoning effect that draws the fluid into the pump casing. 离心泵的自吸装置原理涉及使用真空或气压来产生虹吸效应，将流体吸入泵壳。

One common method of ensuring self-priming in a centrifugal pump is by using a built-in or external priming chamber. This chamber serves as a reservoir for the initial fluid supply and also helps to create the necessary vacuum or pressure to initiate the self-priming process. 一种确保离心泵自吸的常见方法是利用内置或外置的自吸室。

该室作为初始流体供应的储存器，并帮助产生必要的真空或压力来启动自吸过程。