Unit 21
Pumps
1. Introduction
Pump, 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。水泵的操作压力从一磅到一万磅每平方英尺。日常生活中，泵是很多的，有用于在鱼池和喷泉使水循环和向水中充气的电泵，还有用于从住宅处把水引走的污水泵。
Two types of modern pumps used to move water are the positive-displacement pump and the centrifugal pump. Positive-displacement pumps use suction created by a vacuum to draw water into a closed space. An example of this type of pump is the lift, or force, pump used commonly in the rural United States until the mid-1900s. The lift pump is operated by raising a handle that is attached to a piston encased in a pipe. Lifting the piston creates a partial vacuum beneath it in the pipe, causing water to be drawn from a well below , through the pipe, and into a chamber in the pump. A one-way valve closes after water is pumped into the chamber, keeping the water from flowing back down into the well. Subsequent pumps of the piston pull more water into the chamber, which eventually overflows, spilling water out of a spout. Centrifugal pumps use motor-driven propellers that create a flow of water when they rotate. The blades of the propeller are immersed in the water to be pumped. As the propeller turns, water enters the pump near the axis of the blades and is swept out toward their ends at high pressure. An alternative, early version of the centrifugal pump, the screw pump, consists of a corkscrew-shaped mechanism in a pipe that. when rotated, pulls water upward. Screw pumps are often used in waste-water treatment plants because they can move large amounts of water without becoming clogged with debris. In the ancient Middle East the need for irrigation of farmland was a strong induceDlent to develop a water pump. Early pumps in this region were simple devices for lifting buckets of water from a source to a container or a trench. Greek mathematician and inventor Archimedes is thought to have devised the first screw pump in the 3rd century Be. Later, Greek inventor Ctesibius developed the first lift pump. During the late 17th and early 18th centuries AD, British engineer Thomas Savery, French physicist Denis Papin ..and British blacksmith and inventor Thomas Newcornen. contributed to the development of a water pump that used steam to power the pump s piston. The steam-powered water pump's first wide use was in pumping water out of mines. Modern-day examples of centrifugal pumps are those used at the Grand Coulee Darn on
the Columbia River. This pump system has the potential to irrigate over one million acres of land. 现在，两种典型的排水泵是容积泵和离心泵。容积泵通过由真空产生的吸力把水引到一个紧凑的地方。这种类型泵的一个实例就是提升或压力泵，在20世纪中叶美国农村普遍使用。提升泵的操作是通过一个与被管子包住的活塞手柄来进行的。当我们提升活塞时在管子下部产生一个局部的真空，这样我们就用管子从下面的取水，并且送到泵的一个空间。当水被泵吸入时，单向阀关闭，阻止水流回到井下。接着泵的活塞吸入更多的水进入泵的膛体中。这样最后形成溢流，水从管口处流出。而离心泵时使用了一种螺旋推进器，旋转时使水流动，而且推进器的切片是在泵送水时侵入水中的。而且，当推进器旋转时，水进入位于刃片的轴部的间隙并且以很高的压力甩向底部。与它类似，离心泵的早期形式，螺杆泵，通过一个管子螺丝钉的组成，当旋转时，把水提升上去。螺旋泵经常用在污水处理厂中，因为他们可以运输大量的水，而不会因为碎片而堵塞。在远古的中东，因为对农场进行灌溉的需求，所以有一种强大的动力去推进水泵的进程。在这些区域里，早期的泵是为了将水一桶一桶的从水源或河渠中提升到容器中。古希腊的发明家和数学家的阿基米德泵认为是公元前3世纪首先提出螺旋泵的发明家。之后，古希腊发明家发明了第一个提水泵。在十七世纪末和十八世纪初，英国的工程师Thomas Savory，法国的物理学家Denis Pa]pin，和英国的铁匠和发明家Tomas Newcomen,它们发明了用蒸汽驱动活塞的水泵。蒸汽驱动的水泵首先广泛的被应用在从煤矿往外输水过程中。现在离心泵使用的例子，可以是在哥伦比亚河上使用的大古利水坝。这个泵有超过灌溉一百万英亩的土地能力。
2. Reciprocating Pumps
Reciprocating pumps consist of a piston moving back and forth in a cylinder that has valves to regulate the flow of liquid into and out of the cylinder. These pumps may be single or double acting. In the single acting pump, the pumping action takes place on only one side of the piston, as in the case of the COD1ll1on lift PUDlP, in which the piston is moved up and down by hand. In the double acting pump, the pumping action takes place on both sides of the piston, as in the electrical or steam-driven boiler feed pump, in which water is supplied to a steam boiler under high pressure. These pumps can be single-stage or multistaged, Multistaged reciprocating pumps have multiple cylinders in series.
2. 往复泵
往复泵有一个在圆筒中上下移动的活塞，可以使水规则的流入或流出圆筒。这些泵可以是单作用的，也可以是双作用的。在单作用的泵中，泵的作用仅仅发生在活塞的一侧，典型的例子就是升液泵。在升液泵中，活塞通过手上下移动。在双作用的水泵中，泵的作用发生在活塞的两侧，比如说电动的或气动的锅炉给水泵，水以高压通过蒸汽锅炉供给。这些泵可以是单级的也可以是多级的。多级的往复泵的泵系列有多个刚体。
3. Centrifugal Pumps
Also known as rotary pumps, centrifugal pumps have a rotating impeller, also known as a blade, that is immersed in the liquid. Liquid enters the pump near the axis of the impeller , and the rotating impeller sweeps the liquid out toward the ends of the impeller blades at high pressure. The impeller also gives the liquid a relatively high velocity that can be converted into pressure in a stationary part of the pump , known as the diffuser. In high-pressure pumps , a number of impellers may be used in series, and the diffusers following each impeller may contain guide vanes to gradually reduce the liquid velocity. For lower-pressure pumps, the diffuser is generally a
spiral passage, known as a volute, with its cross-sectional area increasing gradually to reduce the velocity efficiently. The impeller must be primed before it can begin operation, that is, the impeller must be surrounded by liquid when the pump is started. This can be done by placing a check valve? in the suction line, which holds the liquid in the pump w-hen the impeller is not rotating. If this valve leaks, the pumps may need to be primed by the introduction of liquid from an outside source such as the discharge reservoir. A centrifugal pump generally has a valve in the discharge line to control the flow and pressure. For low flows and high pressures, the action of the impeller is largely radial. For higher flows and lower discharge pressures, the direction of the flow within the pUD1P is more nearly parallel to the axis of the shaft, and the pump is said to have an axial flow. The impeller in this case acts as a propeller. The transition from one set of flow conditions to the other is gradual, and for intermediate conditions, the device is called a mixed-flow pump.
3
离心泵
离心泵被认为是旋转泵，它是有一个旋转地叶轮，也有刃片，刃片是侵入液体中。液体也是由叶轮轴向进入泵，并且旋转的叶轮将液体甩向叶片根部。同时叶轮也给液体一个较高的过度，这个过度能够使泵的一个固定部件转化成压力。我们一般称为扩压器。在高压泵里，很多叶轮可以被系列选用，并且在一个叶轮后有一个扩压器，也可能含有导轮，可以逐渐的降低液体的过度。对于低压泵来说，扩压泵一般就是一个螺旋形的通道，成为蜗壳，作用原理是拦截面逐渐增加可以有效降低流体的过度。在泵工作前，叶轮必须被灌注，也就是在泵启动时，叶轮必须被液体包围。也可以通过在吸入线上放另一个截止阀来实现，截止阀在泵停止工作时是液体保留在泵内。如果阀泄露了，泵可以通过阀的入口，从外面的水源比如说蓄水池来取水灌注。一般离心泵在排水线也有一个阀控制流体和压力。对于小流量和高压力来说，叶轮作用很大部分是放射状的。对于高速流体和低压排水压力，泵中流体的方向可以近似于与轴的轴向平行，这时泵有一个轴流。这时叶轮就近似于螺旋推进器。从一种流的状态转换到另一种流的状态是渐进的，对于中间状态，设备可称为混流泵。
4. Jet Pumps
Jet pumps use a relatively sznall stream. of liquid or vapor, moving at high velocity, to move a larger flow of fluid. As the high-velocity stream passes through the fluid, it carries some of the fluid out of the pump; at the same time, the high-velocity stream creates a vacuum that pulls fluid into the pump. Jet pumps are often used to inject water into a steam boiler. Jet pumps have also been used to propel boats, particularly in shallow water where a conventional propeller might be dam.aged.
4
射流泵
射流泵是通过一个流量相对较小的液体或蒸汽，以较高速度移动到较大的液流。因为高速流体要通过液体，它从泵里带走液体一部分，同时，高速流产生一个真空，这个真空又把液体吸入泵内。射流泵经常给蒸汽锅炉注水。另外，也应用来推动的船只，特别是在正常的推进器可能被破坏的浅水里。
5. Other pumps
A variety of positive-displacement pumps are also available, generally consisting of a rotating member with a number of lobes that move in a close-fitting casing. The liquid is trapped in the spaces between the lobes and then discharged into a region of higher pressure. A common device of this type is the gear pump, which consists of a pair of meshing gear. The lobes in this
case are the gear teeth. A simple but inefficient pump can also be constructed by having a screw turning in a casing and pushing the liquid along. A similar pump was first invented by the Greek mathematician and physicist Archimedes sometime after 300 Be. In all these pumps the liquid is discharged in a series of pulses and not continuously, so care must be taken to avoid resonant conditions in the discharge lines that could damage or destroy the installation. For reciprocating pumps, air chambers are frequently placed in the discharge line to reduce the magnitude of these pulsations and to make the flow more uniform.
5
其他类型的泵
仍然存在其他很多类型的容积泵，一般用带有很多保密配合的圆形突出的回转件。液体被收集在耳朵之间，而且被转送到一个压力较高的区域。这种泵的一个典型设备是齿轮泵，包含有一对网状齿轮，在齿轮泵里耳朵就是齿牙。也可通过一个在外壳旋转的螺杆来构造一个简单而低效的泵，螺杆推动也提前进。一个相似的泵在公元前3世纪被希腊数学家和物理学家阿基米德发明了。在所有的泵里，液体被一些列脉冲排出，并且不连续。因此我们必须注意在排除线上来避免共振，因为共振可能会损伤或破坏整个设备。对往复泵来说，真空经常放在排除线上，可以减少振动，并使流动均衡。
Unit 22
Pumping Equipment for Gases
Essentially the same basic types of mechanical equipment are used for handling gases and liquids, though the construction may be very different in the two cases. Under the normal range of operating pressures, the density of a gas is considerably less than that of a liquid so that higher speeds of operation can be employed and lighter valves fitted to the delivery and suction lines. Because of the lower viscosity of a gas there is a greater tendency for leakage to occur, and therefore gas compressors are designed with smaller clearances between the moving parts. Further differences in construction are necessitated by the decrease in volume of gas as it is compressed , and this must be allowed for in the design. 'Since a large proportion of the energy of compression appears .as heat in the gas, there will normally be a considerable increase in temperature which may limit the operation of the compressor unless suitable cooling can be effected. For this reason, gas compression is often carried out in a number of stages and the gas is cooled between each stage. Any gas which is not expelled from the cylinder at the end of compression (the clearance volume ) must be expanded again to the inlet pressure before a fresh charge can be admitted. This continual 'compression and expansion of the residual gas results in loss of efficiency' because .neither the compression nor the expansion can be carried out completely reversibly'. With liquids this factor has no effect on the efficiency because the residual fluid is not compressed.
Unit 22 气体的泵设备
对于处理戒指为气体或液体来说，虽然设备在结构上有很大差异，但这两种设备在本质上属于相同基本类型的机械设备。在正常操作范围内，因为气体的密度比液体小，所以对气体的操作可达到较高的速度，而且在吸入线和排出线上可使用较轻的阀。因为气体的粘度小所以它们容易发生泄露。因此气体压缩机的移动部件之间的间隙被设计的非常小。因为气体压缩过程中体积减小，因此与液体相比在结构上存在差异，而且这个差异在设计中也要考虑。压
缩机中很大一部分能量要被转换成热能。因此在没有合适的冷却措施时将会限制压缩机的操作。也因为这个，气体压缩机分为多级完成，而且每一级中可分别冷却。任何在压缩机中没有被排出缸体的气体，再重新充入时要膨胀到入口的压力。残余的气体连续压缩和膨胀导致效率下降，因为不管是压缩还是膨胀都不能被可逆操作。
The principal types of compressors for gases are described as follows.
而对液体，间隙容量不会影响效率的，因为残余液体不可压缩。
Reciprocating piston compressor'"
往复式活塞压缩机
This type of compressor which may consist of from one to twelve stages is the only one capable of developing very high pressures, such as for example over 350 M;N 1m2 as required for polythene manufacture. A single-stage, two?cylinder unit, shown" in Fig. 5. 4, "operates at relatively slow speed and is being replaced wherever possible by the centrifugal type 'Which can now develop all but the very highest pressures .
这种压缩机可以包含1—12级，是唯一可以达到较高压力的设备，比如在乙烯工业中所需水的压力达到超过350万牛/每平方米，图5.4是单级双缸的压缩机，操作速度低，在操作压力较低时可以用离心压缩机取代。
Rotary blowers and compressors
旋转式鼓风机和压缩机
These can be divided into two classes-those which develop a high compreseion ratio and those which have very low ratios. The former include the sliding-vane type@) in which the compression ratio is achieved by eccentric mounting of the rotor (Fig. 5. 5) and the Nash Hytor pump (Fig. 5. 6) in which the compression ratio is achieved by means of a specially shaped casing and a liquid seal which rotates with tile impeller.这种压缩机可以分为较高压缩和较低压缩两种类型。前者包含滑片式，它的压缩比是通过离心转子来实现的。Nash Hytor泵是通过特殊形状的刚体和叶轮同时旋转的液体密封来实现的。
In the sliding-vane unit the rotor is slotted to take the sliding blades which subdivide the crescent-shaped space between the rotor and cylinder. On rotation the blades move out trapping the gas which is compressed during rotation and discharged at the delivery port as shown.
在滑片式压缩机通过在壳体上开槽夹住叶片，而叶片将转子和缸体之间的月牙空间分成一片一片的。在旋转时，刃片滑片拦住气体但气体在旋转式被压缩，并且在端口被排出。The Nash Hytor (Fig. 5. 6) type, which is also known as the liquid-ring pump'"; is a positive displacement type with a specially shaped casing and a liquid seal which rotates with the impeller. The shaft and impeller are the only moving parts and there is no sliding contact, so that no lubricants are required and the gas under compression is riot contaminated.
Nash Hytor泵也可以分为液环泵，属于容积泵类型而且带有一个特殊形状的壳体和一个与叶轮同时旋转的液体密封。轴和叶轮是没有移动部件而且没有滑动触点，所以不需要润滑剂，而且被压缩的气体不会受到污染。
With this arrangement the liquid leaves and re-enters the impeller cells in the manner of a piston.
The service liquid is supplied at a pressure equal to the discharge pressure of the gas and is drawn in automatically to compensate for that discharged Irornt he 'ports. During compression the energy is converted to heat so that this is a nearly isothermal .process. Downstream the liquid is separated from the gas and recirculated with any .necessury make up.
在这种压缩机中，液体通过活塞离开和重新进入叶轮单元。工作液体的进口压力与出口压力相等，而且工作液体自动被吸入来补偿出口的液体。在压缩中，能量转化成热，因此这个工艺接近于等温工艺。在下液，液体从气体中分离出来通过必要的构造进行再循环。
A different kind of unit is represented by the cycloidal or Rootes blower@. In this type, compression is achieved by the rotation of two elernents.. These rotors turn in opposite directions so that, as each passes the inlet, it takes in air which is compressed between impeller and the wall and is than expelled outwards.
还有其他类型，比如摆线型或罗茨鼓风机。在这种类型的压缩机是通过两个部件的旋转来实现的。转子以相反的方向移动，它们通过入口时，带入空气，并将空气在叶轮和壳体之间受到压缩和排出。
Centrifugal blowers and compressors'"; including turbocompressors
离心式鼓风机和压缩机，包括涡轮压缩机
These depend on the conversion of kinetic energy into pressure energy. Fans are used for low pressures, and can be made to handle very large quantities of gases. For the higher pressure ratios now in demand, multistage centrifugal compressors are mainly used, particularly for the requirements of high capacity chemical plants. Thus in catalytic reforming, petrochemical separation plants ( ethylene manufacture), ammonia plant-s with a production rate of 12 kg/s, and for the very large capacity needed for natural gas fields, this type of compressor is now supreme. These units now give flowrates up to 140 m3/s and pressures up to 5. 6 MN 1m2 with the newes t range going to 40 MN 1m2? It is important to accept that the very large units offer considerable savings over multiple units and that their reliability is remarkably high. The power required is also very high; thus a typical compressor operating on the process gas stream in the catalytic production of ethylene from naphtha will take 10 MW for a 6. 5 kg/s plant.
这些设备主要服从动能向压能转换，鼓风机用在低压，可以处理大量的气体。对于先不要求较高的压力比的情况，可以使用多级离心压缩机，特别是在要求高产量的化学工厂。因此在催化参照下，石油化工分离工厂（乙烯加工厂），生产进度在１２ｋｇ／ｓ的氨工厂，和产量要求较高的天然气田，这种类型的压缩机是使用最广泛的了。这些流量可达到140 3m/s，压力达到5.6 MN/2m，最新的达到40 MN/2m.。
使用大压缩机与多个压缩机相比，它的经济性和可靠性都很高。能量要求也是很高。对于从粗汽油中，用催化的方式生产乙烯所产生的气体的操作，需要石化厂的流量为6. 5 kg/s压力为１０MW的能量。
Unit 23
Solid Liquid Separation
It is difficult to identify a large-scale industrial process 'Which does not involve some form of solid-fluid separation. In its entirety, the latter activity involves a vast array of techniques and machines, This book is concerned only "With those parts of this technological diversity which
relate to solid-liquid separation (SLS)
对于大规模的工艺来说，很难找到不包含一些固液分离的形式。对于整个工业来说，近来一些工作包含大量的技术和机器。本书主要介绍与与固液分离有关的工艺多样性。.
Attempts have been made [Svarovsky, 1981 Jto catalogue the variety of processes and machines used in SLS systems , these are usually based on two principal modes of separation : (1) Filtration, in which the solid-liquid mixture is directed towards a "medium" ?(screen, paper, woven cloth , . mermbrane , etc. ). The liquid phase or filtrate flows through the latter whilst solids? are retained, either on the surface, or within the medium.
在１９８１年Svarovsky做出了努力将在固液分离中不同种类的工艺和机器装成册。这些基于两种主要的分离模式。（１）过滤，在过滤过程中固液混合物共同流向一个媒介，（筛子，滤纸，织布，薄膜，等等）。液相或滤出液流过媒介，故乡被保留在媒介表面或中间。(2) Separation by sedimentation or settling in a force field (gravitational, centrifugal) wherein advantage is taken of differences in. phase densities between the solid and the liquid?. The solid is allowed to sink in the fluid, under controlled conditions. In the reverse process of flotation, the particles rise through the liquid, by virtue of a natural or induced low . "solids " density.
（２）
在一个力场作用下通过沉降或沉淀进行分离，在力场（重力场，离心场）中的沉降分离是利用固相和液相的密度差。固体在人为控制下在液体中下沉。对于一个浮选相反的工艺，介质从液体中上升，利用固相的一个自然优点或外加的低固相密度优点。
The large range of machinery reflects the uncertainty which attaches to the processing of solids, particularly those in small particle size ranges.
大部分机械都反应了与固体处理相关的不确定性，特别是较小颗粒尺寸范围。
The filterability and sedimentation velocity of such mixtures depend on the state of dispersion of the suspension; in turn, the latter is strongly influenced by solid-liquid surface conditions 'Which govern the stability of the mixture and the overall result of particle-particle contact. The properties of such systems may also be time dependent, with filterability' and settling rate being a function of the history of the suspension [Tiller , 1974J.
这种混合物的过滤性和沉积速度主要取决于悬浮液的浮散状态，反过来浮散状态很大程度上，受控制混合物的稳定性和控制质点与质点接触整体状态的固液所影响。这种系统的特性也可满足随时间而定的，他们的过滤性和沉积进度是悬浮液经历的一个函数。
The dispersive and agglomerative forces present in these systems are function of pH t temperature, agitation, pumping conditions, etc@. all of which complicate the situation and produce the result that suspension properties cannot be explained in hydrodynamic terms alone. Despite these formidable problems, modem filtration and separation technology continues to produce separations in seemingly intractable situations, and to eliminate the' "bottle neck" characteristic of the SLS stage in many processes.
这些系统中的分散力与凝聚力是ＰＨ值，温度，搅拌状态与泵作用等条件的函数。所用这些方面的情况变得复杂，并且让我们认识到悬浮液的特性不能用水力间距来解释。尽管有这些困难的问题，现代过滤和分离工艺不断被新的技术似乎比表面上看起来更加难所取代。消除在很多工艺中固液分离的瓶颈特性。
A first step in the rationalisation of such problems is to choose the most appropriate technology from filtration, sedimentation or a combination of these two operations. In general, sedimentation techniques are cheaper than those involving filtration; the use of gravity settling would be considered first, particularly where large, continuous liquid flows are involved [Pierson
1981 J.
对于这个问题，采取的合理的方法第一步是选择最恰当的技术，或过滤，或沉淀，或两者的合并。通常，沉淀技术比那些含有过滤的技术要经济。利用重力沉淀是要考虑的，特别是大流量和连续性的工艺中。
A small density difference between the solid and fluid phases would probably eliminate sedimentation as a possibility, unless the density difference can be enhanced, or the force field of gravity increased by centrifugal action. Such techniques for enhancing sedimentation the nature of the particulates was such as to make filtration "difficult". The latter condition would ensue when dealing with small , sub-micron material, or soft, compressible solids of the type encountered in waste water and other effluents. Some separations require combinations of the processes of sedimentation and filtration; preconcentration of the solids will reduce the quantity of liquid to be filtered and, therefore, the size of filter needed for the separation.
在液相和固相之间，密度查一下哦，似乎不能用沉降工艺，除非密度差异可被扩大或通过离心作用来增加重力场。为提升沉降能力这些工艺为那些不能进行重力分离和因为颗粒的特性而难于进行过滤的分离提供可能。后面这种情况在处理小的次微小的材料或软的可压缩的固体时跟着发生在污水或流出物中。一些分离方法需要的沉降和过滤工艺，将固体集中，将减少流过液体的量，而且过滤器尺寸也减小了。
Having decided upon the general separation method , the next stage is to consider the various separational techniques available within the two fields. These operational modes may be listed as:
在决定一般分离方法后，下面就要考虑在这两个区域所存在的分离技术。操作方法如下：(1)Sedimentation: gravity; centrifugal; electrostatic; magnetic
（１）沉降：重力，离心力，静电力，磁力。
(2)Filtration! gravity vacuum: pressure: centrifugal.
（２）过滤：重力，真空，压力，离心力。
Another serious consideration is whether the separation is to be effected continuously or discontinuously; the latter method is known as "batch" processing. In this case, the separator acts intermittently between filling and discharge stages. The concentration of solids in the feed mixture and the quantities to be separated per unit time are also factors which affect the selection procedure.
下一个疑问是分离的连续性还是不连续性操作。不连续操作称为批量操作。在这种情况下，分离设备在填料和排出阶段是间歇作用的。在原料混合物中固体的浓度和单位时间所要求的分离量也是影响选择步骤的因素。
This activity is made more complicated by the fact that the separation stage rarely stands alone. Various pre-and post-treatment stages may be requ ired in the overall? SLS process. Thus, the settling rate of a suspension, or its filterability, may require improvement by pretreatment using chemical or physical methods. After filtration, wet solids are produced, and- these may require further' processing to deliquor (dry) the filter cake; in some cases, the latter, being the principal product, requires purification by washing wit h clean liquid.
因为分离过程很少单独存在，这就使得情况更加复杂。不同种类的预处理和后处理在总体固液分离中有要求。因此，悬浮液的沉淀速度或过滤性可能要求要通过化学或物理方法进行预处理来改善。在过滤后，有潮湿的固体，粗要进一步处理，对过滤块进行干燥。在一些情况下，滤出物为主要产品，需要用干净的液体净化。
It will be apparent that in the development of a typical process for: (a) increasing the solids concentration of a dilute feed, (b) pretreatment to enhance separation characteristics, (c) solids separation, (d) deliquoring and washing , many combinations 'of machine and technique are possible. Some of these combinations may result in an adequate, if not optimal, solution to the problem. Full optimisation would inevitably be time consuming and expensive , if not impossible in an industrial situation. Certain aspects of filter selection are considered at the end of this chapter, on pressure filter process calculations ~
很显然在典型的工艺发展中：（a）对稀释原料增加固体浓度，(b)通过预处理来提高分离特性，（c）固体分离，(d)干燥和洗涤，进行多种技术和机器的组合是可能的。这些组合的充足的，不是最佳的，也会有适当的方法解决问题。完全最优的方法难免会浪费时间而且不经济，如果在工业中不是不可能的。过滤器的选择部分在章末又考虑，过滤工艺的计算压力。
A typical medium for the filtration of coarse materials is a woven wire mesh which will retain certain particulates on the surface of the screen. As the size of the particulates decreases, other "screen" are req u ired, e. g. 'Woven cloths, membranes, etc. ; these are constructed with smaller and smaller openings or pores. Flow through such a system is shown in Fig. 5. 10. Where the particulates are extremely small and in low concentration, deposition may occur in the depths of the medium , such as in water clarification by sand fitters.
在粗粒的原始物料的过滤典型的媒介是金属筛网，它将某些颗粒留在筛网表面。当颗粒尺寸减小时，需要其他一些筛子。例如，机织布，薄膜，等等。这些由越来越小的孔构成。在图5.10中显示流过这样的系统。在颗粒相对小并且浓度低时，沉积作用可能发生在媒介深处，比如用沙子过滤净化。
The filtration medium may be fitted to various Iorms of equipment which, in turn, can be operated in several modes. Thus, plant is available which creates flow by raising the fluid pressure by pumping , or some equivalent device. Such "pressure" filters operate at pressure levels above atmospheric; the pressure differential created across the medium causes flow of fluid through the equipment. Plant of this type can be operated at constant pressure differential or at constant flow rate. In the latter case the pressure differential will increase with time whilst at constant pressure, liquid ￡low rate decrease with time.
过滤网或过滤媒介需要适合多种设备。反过来说，设备也可能进行多种操作，因此设备可以通过泵设备作用提高流体压力，或化学设备。这种压力过滤在高于大气压下工作；压力差异使流体通过媒介而通过设备。这种类型设备可以再标准压力差下操作或稳定流速下操作。在最近条件下，压力差在压力不高条件下增加，流速随时间降低。
24
Valve , a mechanical device used to control the flow of a gas or liquid, or-in the case of a check valveCD-to ensure that flow travels in only one direction. Valves range in, size from the small valve of an automobile tire to large valves used in the control of locks and dams; these large valves can measure more than 5 m (16 ft) in diameter. Small and low-pressure valves are usually made of brass, cast iron, or plastic, while large pressure valves are made of cast or forged steel. Other alloys, such as stainless steel may be required if the controlled fluid is corrosive. Valves may be actuated manually, mechanically through a servomechanism, or by the flow of the controlled
fluid
阀，是一种控制液体或气体流动的机械。例如截止阀，是保证流体沿一个方向流动。阀的尺寸范围很大，小的用在汽车轮胎的阀，大的用在控制水闸和大坝上。大阀的直径可能超过五米。小阀和低压阀通常由黄铜，铸铁，塑料制造，而较高压力的阀是用锻钢制造的。其他合金，比如不锈钢可能用在控制流体有腐蚀作用的流体上。阀可以手工操作，可以由伺服机构机械操作，或由所控制液流操作。
Basically there are only four types of valve+-rotary , lift, slide and piston@-and theirevolution w-as undoubtedly in this order.
基本上由四种类型的阀，回转阀，提升阀，滑阀，活塞阀。而且毫无疑问它们的发展也是这个顺序。
There are many variants, however, of these four basic types, as may be expected; yet all are alike in concept and, despite the present-day trend for greater simplification and standardization, it seems clear that the advent of ne-w industrial processes and techniques, and the discovery of new, and sometimes exotic, materials of construction, will promote these variations, perhaps with" increasing intensity.
四种基本类型有很多种变体。然而所有变体与母体在原理上是相似的。尽管目前发展趋势越来越标准化，越来越简化。新型工艺和技术的出现预计新的发现和外来的，结构材料的发现。将促进这些变形，也许速度越来越快。
Four fundamental designs, and their variants, in common usage, all reliant on manual operation, are dealt with in the first four chapters. The alert designer should, however, have no trouble adapting the reasoning used to designs having similar characteristics to those chosen by way of example
四种基本设计以及变形，在一般使用中，都依赖手动操作，在最初的四章中讨论，对于警惕的设计者，他们会毫不犹豫将所有的推理与通过实例选择与相似特性的设计配合起来。The sequence of the first four chapters is in order of evolution of the valves, but it is 'of interest to note that the timescale is somewhat logarithmic. For example, the earliest valve-the cock was introduced before the Christian era; the screw-down valve, circa 1790; the wedge-gate valve in 1839 and the parallel slide valve in 1884. All are basically stop valves arranged for manual operation, and, in more recent times for operation by some form of motive power.
最初的四章是按阀的发展来安排的，但是我们要注意时间分布稍微有对数的特征，。例如，早期的阀，旋塞阀，是在公元前发明的。螺杆阀，大约是在1790年，闸阀是在1839年，平行滑阀是在1884年。所有这些堵塞阀都是用手操作的，到了最近它们才通过某些形式的动力来操作。那些自动工作的阀，比如安全阀或泄压阀，减压阀，非回流阀，凝气阀和相似的设备。另外属于一类，并且在下面的五章中进行讨论，这些阀假如用精确意义上的要求来表达就是自动机器。在正确的设计和安装之后，每一个阀都很正确的执行相应的功能，毫不夸张的说有的是一天到头，有的是一年到头。
Valves which function automatically, such as safety or relief valves, reducing valves, non-return valves, steam traps and similar devices, are in a class apart and are dealt with in the remaining five chapters. These valves are automatons in the strict sense of the word. Correctly designed and installed, each may Valves which function automatically, such as safety or relief valves, reducing valves, non-return valves, steam traps and similar devices, are in a class apart and are dealt with in the remaining five chapters. These valves are automatons in the strict sense of the word. Correctly designed and installed, each may be relied upon to perform its appointed function, unostentatiously maybe , day-in, day-out, m.ore likely year-in, year-out.
那些自动工作的阀，比如安全阀或泄压阀，减压阀，非回流阀，凝气阀和相似的设备。另外属于一类，并且在下面的五章中进行讨论，这些阀假如用精确意义上的要求来表达就是自动机器。在正确的设计和安装之后，每一个阀都很正确的执行相应的功能，毫不夸张的说有的是一天到头，有的是一年到头。
The safety or relief valve, an essential adjunct to any piece of equipment which can justly lay claim to being a pressure vessel@, is particularly note-worthy by reason of the essential role it plays in the safeguarding of life, limb and property. By "pressure" we infer "absolute pressure", since vessels operating at sub-atmospheric pressure generally require some means of automatic protection if they are liable to collapse under the crushing effect ofthe atm.osphere should a vacuum be created inside them from any cause whatsoever. The other examples, important as their respective function might be, 'Would be less likely to engender such doleful consequences should they fail in their appointed functionj but no less care should be lavished on their design on this account.
对已认定的压力容器的设备，安全阀或减压阀是必要的附件。特别值得注意的，因为它是我们生命和财产安全的防护装置。有压力到绝对压力，因为容器在大气压力下操作，如果它们容易受到大气压力起决定影响的试问情况，他们需要一些形式上的自动保护，同时在容器内部存在真空不管在任何情况时。另一个例子，各自的作用也很重要。如果它们在工作地点失效，也不会造成太大的损失。但是由于粗心在设计方面没有注意会浪费过多的篇幅。
For those students, engineers, designers and draughtsmen alike, 'Who are confronted with the design or installation of these devices, and who are aware of their necessity, it is hoped this volume 'Will prove to be a vade mecum.
对于那些面临这些设备设计和安装的学生，工程师，设计者，起草者来说还有认识他们必要性的人来说，我们希望通过一篇小记成为一个手册。
With suitable materials of construction and careful attention to design, a parallel slide valve is admirably suited to the control of steam. at the highest pressures and temperatures ..
如果有合适的结构材料，对设计精心考虑，对于高温高压的气体来说平行滑阀是最好的选择。这简单并且最有作用的结构形式是一种带有盘片的弹簧装置，圆盘装配体一般用较小的的阀。
The simplest and most effective form of construction is the one employing 'spring?between-disk" mechanism. The disk assembly is adopted in the smaller sizes of valves.
在紧密圆盘的预压缩的螺旋状的弹簧作用下，套管式装配体的两个相对圆盘又分开的趋势。而对弹簧来说，为了节省纵向空间，一般来说将盘制造成矩形截面，这个结构将两个圆盘压缩以适应阀的较小尺寸。大尺寸阀，两个盘同样压缩并覆盖着一个外接的壳体。
The two opposed disks in telescopic assembly tend to be urged apart under the influence of a close-coiled precornpressed helical spring, usually made of coils of rectangular section in the interests of saving space lengthwise, This arrangement of telescoping the two disks is restricted to the smaller size of valves. In the larger sizes the two disks are identical and are housed in a circum.scribing shell.
在紧密圆盘的预压缩的螺旋状的弹簧作用下，套管式装配体的两个相对圆盘又分开的趋势。而对弹簧来说，为了节省纵向空间，一般来说将盘制造成矩形截面，这个结构将两个圆盘压缩以适应阀的较小尺寸。大尺寸阀，两个盘同样压缩并覆盖着一个外接的壳体。
Let it be understood that the function of the spring is not to secure two pressure-tight facings as is so often presumed; a spring of very much larger proportions would be required for that, which
is anyway not essential and secured only at the lower line pressures. Its function is to prevent vibration or 'chatter' and under appropriate conditions of line pressure to sweep clear, during the transition of the disks, any scale or other undesirable matter which might tend to adhere to the facings and to score them.
我们应该了解到弹簧的作用并不像我们想象那样用来保护这个压力的贴片的。如果需要保护这个贴片就需要一个很大面积的弹簧。它不是必须的，而且只有在较低线性压力下才可以保护贴片。它的作用主要是防止振动或颤动。在适当的线性压力条件下将阀内壁打扫干净。在圆盘运动中，任何尺寸或其他不需要的情况时，将粘到贴片上并且破坏它。
It is inevitable on stearn lines (or in any other application where appreciable temperature variations occur ) for differential expansion to take place due to .the various materials and varying sections in the assembly, and this will give rise to some distortion. With the spring?between-disk mechanism this is taken care of, the disks being free to 'breathe' as it were, the spring yielding in sympathy.
在重要管线上，因为不同区域不同材料的部件的膨胀，并且将增加变形和扭曲。对于盘片和弹簧这种节写结构就要考虑这个。盘片应该能够自由的吸气而且弹簧同时屈服。Pressure-tightness is secured on the downstream face only. If. reference be directed to the closure mechanism assembly, it will be seen that the line pressure exerted on the opposing or upstream disk forces this disk off its seating by a very small amount, and in so doing transmits the resultant force via the spring and, aided by the line pressure', to the downstream disk, the working fluid having access to the inside of the valve casing.
压力密封性只有在下游侧才能获得，如果将这个闭合机械作为整体考虑时，就可以发现作用在相反的或上游的盘片上的线性压力迫使盘片离开阀座。将合力通过弹簧来传递，并在线性压力下，传递到下游的盘片，这样工作的六日进入阀的两级。
Simply by sliding the disks into the low-est possible position the line pressure is utilized to close the valve. This is analogous to the slide valve of a steam engine with the one difference that in this case closure is effected without the aid of a spring or any other external influence other than that of the steam pressure acting on the back of the slide valve.
可以简单的通过滑动的盘片到最低可能达到的位置，并利用线性压力来关闭阀，这与蒸汽机的滑动阀有类似之处。与蒸汽机的差别在于蒸汽机没有弹簧帮助或任何外部的其他影响只有作用于滑阀两侧的蒸汽压力。
Size for size and operating under the same pressure conditions, the parallel slide valve calls for less axial force to be imparted by the stem to secure positive closure than that of the screw-down stop valve. A moment's reflection should reveal 'Why.如果尺寸相同，并且在相同压力下操作，平行阀与螺旋阀相比，所要求的轴向力较小，而轴向力是由正闭合包围，只要稍加考虑就可以知道原因。
Neglecting all secondary resistances, the least force to be exerted in order to close down a screw-dow-n valve is represented by the product of the line pressure and the area of the seating orifice. In the parallel slide valve, the least force is that required to slide the downstream disk across its facing and loaded by a force comprised of the line pressure acting on the area of the seating ..
忽略侧面的二次压力，用来关闭螺旋阀的最小的力就是线性压力与底出口面积的乘积。对于平行阀最小的力就是用来将下游盘片滑过贴片的而且也包含作用在底座区域上的线性压力。
25
Classification of any subject, technical or nontechnical, serves the purpose of identifying species, making it easier to analyze the problems involved, Accordingly seals may be classified into two major categories, static and dynamic,
任何物件的分类，技术的还是非技术的，目的是确定一些种类，是更加容易的分析它们所包含的问题。因此密封可以分为两大类，静态的和动态的。
Static seals comprise three major groups known as gaskets, sealants, and direct contact seals
静态密封由三个密封物件组成，包括垫片密封，密封胶密封，和直接接触密封。
Dynamic seals can also be subdivided into t-wo basic groups designated as seals for rotating shafts and seals for reciprocating shafts. These two groups make up the bulk of industrial seals by volume and require specific consideration for predominantly custom-made sealing devices. Further in this category trade names must be used to identify the different devices. These.trade names must be tolerated, since there is no other system for designating most specific devices.
动态密封又可以被细分为两个基本的密封，一种是针对旋转轴密封，另一种是针对往复轴密封。在数量上，两种密封占了工业上的绝大多数。而且对于主要的定做密封的设备要进行特殊考虑。在动密封分类时，需要用商标来确定不同分类的设备。这些商标必须使用，因为没有任何一种方法更加精确地区分设备。
Rotating shaft seals are given special and extensive consideration since they are the dominating category of major industrial seals. They comprise two principal groups, the interfacial seals~~ and the interstitial seals?.
因为旋转轴密封在主要工业中有重要地位，所以必须给与特别细致的考虑。被分为两种类型，界面密封和间隙密封。
The interfacial seals subdivide into axial seals and radial. seals. Interfacial seals represent a very large family of industrial sealing devices that establish a direct contact between the sealing component and the rotating_ shaft.
界面密封别细分为轴密封和径向密封。截面密封提出了工业密封是一个大家族。主要是密封件和旋转轴之间有一个接触。
Interatitial seals categorize a family of four distinct groups in 'Which the scaling components have no direct m.echanical contact with the rotating shaft. The sealing elements allow a certain leakage that retards flow by controlling the clearance gap through which the fluid flow may pass using external forces on the fluid.
间隙密封描绘了包括四个截然不同的种类的家族。与旋转轴成比例的部件。密封元件允许一部分泄露来控制外力作用下的流体可以通过的间隙尺寸。
The function of interstitial seals is to create a pressure drop of the fluid to be sealed with the least possible flow and simultaneously to permit unrestricted relative motion between moving parts. Interstitial seals are capable of maintaining a pressure differential between the interior of a machine and its surrounding environment by distinctly throttling the escaping fluid .. Unlike interfacial seals, no mechanical contact of moving machine parts is intended. This reduces friction to an absolute minimum. To throttle fluid in a controlled manner, however, it is necessary to allow a nominal flow.
间隙密封的功能是在被密封的流体上产生一个压降，同时允许在自由的部件运动中存在相对
运动。间隙密封能在机器内部与环境之间产生一个压力差。不想界面密封，移动的部件之间没有接触是故意的。将摩擦降低到一个最小值。为了以一种控制方式来限制流体，然而，必须允许稍微的流动。
Examples of such interstitial seals are viscoseals , labyrinth seals@, and bushing seals. The family of the ferrofluidic seals, however, is a clear exception. Here the gap for the clearance fluid is filled with a magnetic medium that is held captive ?without flow with the help of a more or less strong magnetic field. Mechanical parts to establish a seal do not exist. With interstitial seals no rubbing contact exists; hence friction and wear of moving parts in the direct seal environm.ent are practically eliminated.
间隙密封的实例是黏胶密封，速度密封和轴封。铁磁流体是一个例外，按间隙的大小充满磁介质，在一个磁场或多或少的帮助下，将磁介质约束在间隙内，需要建立一个密封的机械部件不重要，因为间隙密封无任何滑动接触，因此运动部件之间的摩擦或磨损全部被消除。作为轴向密封的设备的机械端面密封
Mechanical End Face Seals as Axial Sealing Devices
作为轴向密封的设备的机械端面密封
Compared with the gaskets , end face seals , which are also generally known as mechanical seals, employ a unique and different sealing principle. Mechanical seals were first massively applied in the automotive industry for sealing engine coolants and water systems. They are now used even more extensively in this application and have confirmed their enormous importance to an industry.
与垫片密封相比，端面密封是机械密封，使用单一的和不同的密封原则。机械密封第一次被大规模的应用在汽车工业中，用于发动机冷却液和给水系统。现在使用的更加广泛而且证明了对一种工业的重要性。
In chemical , petrochemical , utility , and related industries , the mechanical seal has gained considerable importance because of the constantly improving technology with respect to sealing techniques and construction materials used in sealing components. Ever-increasing temperature and pressure demands , in addition to increasing rotational shaft speeds , have created a climate that forces the progressive seal designer constantly to widen his horizon.
在化工，石油化工，公共事业，机关事业，随着密封技术以及用于密封配件的结构材料的技术的不断改进，机械密封体现了很大的价值。除了轴转速的要求提高以及不断增长的温度和压力的要求，所以现代密封设计者要不断扩大视野。
Fundamentals of Mechanical End Face Seals
机械端面密封的原理
Mechanical end face seals are now fabricated by the millions and by a considerable number of renowned sealing companies all over the world.
机械端面密封被成千上万的世界知名的密封设计公司制造。
The state of the art for mechanical seals has developed a degree that pressures from high vacuum of 10-5 torr up to 5000psi (.-..... 350 atm ) can be handled safely'". New materials and particularly metal bellows have made it possible to handle temperatures up 1000 °c ( ~ 1830*F) and down to the cryogenic range with confidence. Rotational shaft" speeds of up to 50000 RPM are no longer impossible. 机械密封目前的技术水平已发展到这样的程度，从5
10
托的高真空度到5000磅/平方英寸都能处理。新型材料，特别是金属波纹管，使
得机械密封的适应范围到达1000℃低的达到低温允许范围内。轴的旋转达到50000 RPM不是不可能的了。
A mechanical seal represents a complex design that consists of ~ series of single design components. The sealing function is achieved by two primary seal rings with faces to prevent leakage. One of the primary seal rings is attached to the shaft and rotates with it; the other primary seal ring is stationary and is attached to the housing. 'To seal the shaft of a centrifugal pump the stationary primary seal ring is mounted to the gland plate ring. During rotation of the pump shaft t the primary seal ring attached to the shaft rubs with its seal face along the counterseal face of the stationary ring. Thus the two interface contact areas function like bearings and are subject to frictional wear. Any kind of leakage of the system fluid must pass across this interface. 机械密封是复杂的，包括一系列单各组件的设计，主要通过两个带有贴片的密封环来防止泄露实现密封。重要密封环的一个是连在轴承上并且随它一起运动，另一个密封环是固定的并与壳体相连。对于一个离心泵轴密封来说，这个固定的密封环固定在密封管板环上。在泵轴旋转中，链接到轴上重要密封环，用它的密封沿着固定环的密封面摩擦。因此这两个界面的连接区域像轴承一样工作，而且受摩擦力磨损。任何流体泄露时都流过这个表面
The rubbing contact is continuously maintained by forces acting in axial direction. The origin of the axial pushing forces can be either mechanical or hydraulic. In many designs it is the SUlll of both. Pushing forces are required to establish and maintain a continuous contact between the components forming the interface. This steady contact either prevents or minimizes leakage across the rubbing areas.
因为作用在轴线方向的里使得摩擦接触一直存在。轴向推力可能是机械力也可能是水力。在很多设计中是两者共同作用。推理来建立并保持在轴部间的连续接触并形成界面。稳定的接触防止了或最小化了摩擦区域的泄露。
Rubbing action between solid interface areas produces heat and wear even when there is good lubrication. This heat builds up and finally results in the destruction of the interface contact areas. In order to prevent this, lubrication is applied that has a twofold purpose. First, it removes the heat from the area of rubbing contact and thus reduces the detrimental temperature buildup. Second t the lubricant covers the interface with a minute film that reduces friction and simultaneously establishes a tight seal.
在固体接触区域摩擦作用产生的热和磨损的存在良好的润滑下。热积累并最终导致摩擦区域的破坏。为了防止这样，应用具有双重作用的润滑剂，首先将摩擦接触产生的热带走进而减少了热的积累。其次，润滑剂用一个微小的薄膜将介质覆盖从而减小摩擦同时建立以份额紧密的密封。
The lubricant fluid can be either the fluid of the pump system or a secondary fluid,which can be water or any other liquid compatible with the system fluid to be sealed.
The extremely thin lubricant film across the ~ interface is the key to good sealing performance of mechanical end face seals, the function of w-hich is still considered a mystery.
It is not secret that a reliable and accurate design analysis for mechanical end face seals does not exist. Accordingly, all tnechanical seals have thus far been developed on a purely empirical basis. Any new seal design obviously O1USt be tested empirically, because a prediction of the eventual
performance characteristic of the seal is not possible on any reliable theoretical basis.
润滑剂流体可以是泵系统流体，也可以是另一种流体，可以被输送并与系统任何其他液体相协调。非常薄的润滑薄膜使我们机械断面密封产生良好密封性的关键。，作用依然是一个谜。对一个机械断面来说做一个轴的可靠性分析是不可能的，因为，每一个机械密封都是在一个纯经验注意基础上设计发展的，任何新的密封都设计都必须以经验为主的测试，因为对密封特性是最后表现预测并没有可靠性理论基础。
Unit 26
Introduction to Process Control ( I )
Modern chemical processes have become very sophisticated and simple control procedures are no longer practical. Today's chemical plants utilize the latest electronic hardw-are, automatic controllers, computer controls, advanced analytical monitoring, and advanced control concepts. In order to appreciate the need for this type of control and instrumentation, we must first understand the motive for developing highly automated chemical processes.
现代的化学过程变得非常复杂，简单的控制程序已不再实用。今天的化学工厂采用最新的电子硬件，自动控制器，计算机控制，先进的分析监测，以及先进的控制理念。为了掌握这种类型的控制和检测仪器，我们必须先了解的发展中高度自动化的化学过程。 Reasons for Automating a Chemical Process
1 自动化化学过程原因
Some or possibly all of the following basic benefits are realized when automatic control is introduced into a chemical process:
某些或所有可能的下列基本利益的实现当自动控制时引入化学过程：
(1) The process, whether it is being carried out in bench-scale equipment, a pilot plant, or a full production scale plant, can be run continuously without attention from operators or chemical technicians'". This reduces manpower requirements and therefore lowers labor
costs.
（ 1 ）一种化工过程，不管是在实验规模的设备内或在中间实验装置内，还是在生产规模装置内进行，都能够在无操作人员活化工技术员看管的情况下连续运行。这将减少人力需求，因此，降低劳动力成本
(2) The reduction in need for operating personnel results in an elim.ination or decrease in human errors.
（ 2 ）减少需要操作人员以消除或减少人为错误。
( 3) Chosen adherence to optimum conditions results in an improvement in overall process quality.
（ 3 ）在整个过程的质量选择加入最佳条件改善的结果
(4) Necessary adjustments to operation can be made from one central location often resulting in
a reduction in the space requirements for the process unit.
（ 4 ）必要的操作调整可从一个集中位置往往导致减少过程单元所需的空间的。
(5) Safety in operation is increased by providing warning' of abnormal conditions and automatically taking corrective action. In addition, automatic control eliminates the need for personnel to be in the immediate vicinity of hazardous equipment or conditions,
（ 5 ）操作安全是增加提供预警异常情况，并自动采取纠正行动。此外，自动化控制，无需人员在邻近的危险设备。
2. What is Automatic Control?
2 。什么是自动控制？
A greater appreciation and understanding of an automatic control system can be obtained if we first consider a simple m.anual control procedure. As a way of illustration, suppose "We wish to control the temperature of a solution contained in a beaker on a hotplate at a value of 50°C ± 2 ~C . This might be accomplished by placing a mercury-filled thermometer in the solution, observing the temperature, and then manually adjusting the voltage the hotplate heating element by means of a rheostat so that the temperature is maintained within the desired range. This manual control system contains four basic elements, (1) a detecting device, the mercury bulb;
(2) a measuring device, the mercury column and matching calibration scale; (3) a controlling device, the observer; and (4) the final control element, the rheostat.
Basically, the function of this control system is to measure the value of a variable, the temperature, and then produce a counter response to limit its deviation from a reference point, in this case 50 'C. This is, for all practical purposes, the definition of automatic control. However, in an automatic control systern , the observer, or m.ore specifically' the operator, is replaced in the control loop by a device known as the automatic controller'P
The basic layout of an automatic control loop is shown in Fig. 6. 1. As can be seen, this system contains the same four basic elements of the manual control system described in the preceding paragraph. In addition to these four elements.a transmitter element is often added. However, depending upon the particular variable to be controlled, more than one element may be designed into the same instrument, so that a loop does not always contain four or five separate units.
更加深刻的认识和理解，自动控制系统，可如果我们首先考虑一个简单的手动控制程序。作为举例来说，假设我们要控制的温度，解决载于烧杯的炉具，温度在50 ℃±2 ℃。这可能是由放置一个水银温度计中填充的解决方案，观测的温度，然后手动调整电压的炉具通过变阻器加热元件，使温度保持在理想的范围。这本手册控制系统包含四个基本要素：（ 1 ）检测设备，汞灯泡; 2 ）测量装置，水银柱和匹配标定规模;
（ 3 ）控制设备，观察（ 4 ）最后的控制因素，变阻器。
基本上，这一功能的控制系统，来衡量变量的值，温度，然后产生一个反应限制其偏离参考点，在50 ℃下，。这是对所有的实际目的，定义的自动化控制。然而，在一个自动控制中，观察者，更准确的说是操作者，在控制回路中被一个叫做自动控制器的装置所替代②。基本布局自动控制回路中显示图。 6. 1 。可以看出，这个系统包含相同的四个基本要素的手动控制系统前段所述。除了上述四个因素，发射器的因素往往是补充。然而，这取决于特定的变量加以控制，一个以上的元素可能是设计成相同的工具，因此，环并不总是包含四个不同的单位。
3. What is Controlled in a Chemical Process?
3 。是什么在控制化工过程？
Some of the more important variables that controlled in chemical processes follow.
一些更重要的变量，控制化学过程的后续。
Flow As might be expected, it is important that the material balance requirements of a process be maintained at all times. In a continuous chemical process this requires the control of material flows. Since most chemical reaction-s are sensitive to the ratio of reactants', it is very often a requirement that accurate ￡low control be maintained so that product quality and yield
standards can be met.
流动这种情况是可以预想，重要的是物料平衡要求的过程中，他任何时候都保持人。连续化工过程，这需要控制的物质的流动。由于大多数的化学反应很敏感，反应的比例，它常常是要求准确流量控制得到维持，使产品质量和产量能够达到标准。
Temperature The control of reaction temperature is very important because, as discussed in previous sections, conversion, yields, and product qualities are functions of temperature. Also , proper temperature control is often essential to the successful operation of many separation processes, such as distillation and crystallization .
温度控制反应温度是非常重要的，因为前几节中讨论，转换，产量和产品品质的职能温度。另外，适当的温度控制常常是十分必要的成功运作了许多分离过程，如蒸馏，结晶。
.
Pressure Since many chemical reactions are sensitive to pressure conditions, pressure control is a requirement in most chemical reactors. Most chemical separations also require that the pressure be controlled. For example, distillations are often performed under a reduced pressure, whereas absorptions and adsorptions are carried out at elevated pressures.
压力由于许多化学反应很敏感，压力条件下，压力控制是一个需要在大多数化学反应器。大多数化学离职也需要加以控制的压力。例如，蒸馏往往表现的压力下减少，而吸收和吸附进行了在较高的压力。
Liquid Level Level control is often associated 'With Ilow control; how-ever, there are instances where it is associated with the proper operation of a piece of equipment, such as thelevel of solvent in a solvent extraction tower or the liquid level in a solvent extraction tower or the liquid level in a reactor.
液位水平控制往往与流量控制;然而，有些情况下，它与正常运作的一台设备，如一级的溶剂中的溶剂萃取塔或液位在溶剂萃取塔或液位的反应堆。
The four control parameters cited above comprise the majority of all control applications in the chemical industry. However, the control of variables relating to composition of matter are also frequently encountered.
上面提到的四个控制参数,大多数控制应用在化学工业。但是，控制的变量组成的有关问题，也经常遇到。
Composition Control The control of the composition of matter has been accomplished, depending on the properties of the substances, by a number of different techniques'". The majority of these techniques are based upon one of three different types of analysis: component analysis, physical property analysis, or chem.ical property analysis. Most of the important control loops based upon component analysis utilize the analytical technique of chromatography to determine the mixture composition'['. Although infrared and other forms of spectroscopy also find use in certain processes. A mixture of definite composition often possesses a unique set of physical properties. These properties may actually form part of the product specifications or they may be used as a measure of product composition. Som.e of the nlore common physical properties that are measured and used for control purposes include density, initial and final boiling points, color, freezing point, and viscosity. The composition of a mixture is often related to a unique set of chemical properties. Chemical properties that are most often monitored for control purposes include pH, redox potential, and conductivity.
成分控制根据物料的性质，采用一系列不同的技术，就可实现物质组成的控制③。大部分的这些技术是根据三个不同类型的分析：成分分析，物理性能分析，或化学性质的分析。大
多数以成分分析为基础的重要控制回路，都采用色谱分析技术来确定混个物的组分④。虽然红外和其他形式的光谱也可以在某些进程。混合物的确切成分往往拥有一套独特的物理特性。这些属性实际上可能的组成部分的产品规格，或可能被用来作为衡量产品的成分。一些较常见的物理特性是衡量和用于控制目的包括密度，初步和最后沸点，颜色，凝固点和粘度。组成的混合物常常与一套独特的化学性能。化学特性，往往是监测控制的目的包括pH值，氧化还原电位和电导率。（选：克里斯答：克劳森，原则工业化学， John Wiley ＆ Sons出版公司， 1978 。）
Unit 27
General Concepts of Process Control
Before we go into details in the subsequent sections, it may be worthwhile at this point to define SOD1e very broad and general concepts and some of the terminology used in dynamics and control.
在我们进行随后的章节的详谈前，它可能是值得在这一点上，确定了一些非常广泛和普遍的概念和一些使用的术语，动力学与控制。
1. Dynamics
Time-dependent behavior of a process. The behavior w-ith no controllers in the system is called the openloop response. The dynamic behavior with feedback controllers included with the process is called the closedloop response.
1，动态
一个时间依赖行为的过程。这个行为没有控制器在系统中被称为开环反应。动态特性与反馈控制器包含的进程被称为闭环反应。
2. Variables
Manipulated variables Typically flow rates of streams entering or leaving a process that we can change in order to control the plant.
2，变量
操纵变量通常流速流进入或离开一个过程，我们可以改变，以控制过程。
Controlled variables. Flow rates, compositions, temperatures , levels , and pressures in the process that we will try to control, either trying to hold them as constant as possible or trying to make them follow some desired time trajectory'",
控制变量。即在工艺过程中要试图控制的变量，如：流动速率，组成，温度，液位和压力，要么尽可能使这些量保持为常数，要么尽力使它们沿着某一期望的时间函数而变化。Uncontrolled variables Variables in the process that are not controlled .
不加控制的变量变量在这一过程中没有控制。
Load disturbances Flow rates, temperatures. or compositions of streams entering (but sometimes leaving) the process. We are not free to manipulate them. They are set by upstream. or downstream. parts of the plant. The control system.must be able to keep the plant under control despite the effects of these disturbances.
负载扰动流量，温度，或组成流进入（但有时流出）的进程。我们不能够自由地操纵它们。它们是由上游或下游地区的车间。控制系统必须能够保持车间受到控制，避免这些干扰的影响。
3. }'eedback control
The traditional way to control a process is to measure the variable that is to be controlled, compare its value with the desired value (the setpoint to the controller) and feed the difference
(the error) into a feedback controller that will change a manipulated variable to drive the controlled variable back to the desired value. Information is thus "fed back" from the controlled variable to a manipulated variable, as sketched in Fig. 6. 5.
3，反馈控制
以传统方式来控制一个过程是衡量的变量是控制，比较它的数值与理想值（设定的控制器）和填补的差异（错误）为反馈控制器，将改变操纵变量驱动控制变量返回的值。信息是“反馈”的控制变量为操纵变量，如图6.5描绘。
4. Feedforward control
The basic idea is shown in Fig, 6. 6. The disturbance is detected as it enters the process and an appropriate change is made in the manipulated variable such that the controlled- variable is held constant+ . Thus we begin to take corrective action as soon as a disturbance entering the system is detected instead of warning (as we do with feedback control) tor the disturbance to propagate all the way through the process before a correction is made'",
4. 前馈控制
基本思路如图6.6示。当干扰信号进入过程时，被检测器检测到，同时操纵变量相应的改变，以使被控制变量保持为常量。这样，一旦干扰信号进入被检测系统，马上就可采取纠正措施，而不是（像反馈控制那样）只发出警告，干扰信号则在被纠正之前一直通过过程进行传递。
5. Stability
A process is said to be unstable if its output 'becomes larger and larger (either positively or negatively) as time increases. Examples are shown in Fig. 6. 7. No real system really doesthis, of course, because some constraint will be met, for example, a control valve will completely shut or completely open, or a safety valve will "pop". A linear process is right at the limit of stability if it oscillates, even when undisturbed ? and the amplitude of the oscillations does not decay.
5. 稳定性
一个过程被认为是不稳定的，如果其输出越来越大（无论是正面还是负面的）随着时间的增加。例如图6.7所示。当然，没有一个实际的系统能真正做到这一点，因为在系统中会遇到一些制约因素，例如，一个控制阀可能全闭或全开，或者一个安全阀突然开启。一个线性的过程在稳定性的限制上是正确的如果它是不稳定的，即使在不受干扰和振幅振荡不衰减。Most' processes are openloop stables i. e. , "stable with no controllers on the system. One important and very interesting exception thatwe will study in some detail is the. exothermic chemical reactor which can be openloop unstable. All real processes can be made closedloop unstable (unstable when a feedback controller is in the system) if the controller gain is made large enough. Thus stability is of vital concern in feedback control systems.
大多数的过程是开路稳定，稳定的同时系统没有控制。一个重要的和非常有趣的例外，我们将研究在一定程度上详细的放热化学反应器可开路不稳定。所有真正的过程，可闭环不稳定（不稳定时，反馈控制器在系统中）如果控制器增益是够大。因此，稳定在反馈控制系统中极为关注。
The performance of a control system (its ability to control the process tightly) usually increases as we increase the controller gain. 'How-ever, 'We get closer' and closer to being closedloop unstable. Therefore the robustness of the control system (its tolerance to changes in process parameters) decreases: a small change will make the system unstable. Thus there is always a trade-off between robustness and performance in control system. design.
Professional Words and Expressions 1. a code of ethics 道德规范 2.absolute accuracy 绝对精度 3.abstract n. 摘要 4.accountant n. 会计（员），会计师 5.action learning 行动学习 6.adherence n. 忠诚 7.afterwards adv. 之后，以后，后来 8.AGV(Automated Guided Vehicles) 自动导航小车 9.aligning results 校正结果 10.alternation ranking method 交替排序法 11.AM(Agile Manufacturing)敏捷制造 12.analyst n. 分析者；善于分析者；分解者 13.anatomical adj. 解剖的，解剖学 14.annual bonus 年终分红 15.anthropometric adj. 人体测量的 16.anthropometry n. 人体测量学 17.appeal n. 申诉，请求，呼吁，上诉，要求 18.application forms 工作申请表 19.appraisal interview 评价面试 20.appreciation n. 正确评价 21.aptitudes n. 资质
22.arbitration n. 仲裁 23.architecture n. 结构，构造 24.arena n. 舞台，竞技场 25.assembly line 装配线 26.assessment n. （为征税对财产所作的）估价，评估 27.assurance 确信，断言，保证 28.attract vt. 动手处理（某事）；攻击，抨击 29.attainment n. 到达 30.attendance incentive plan 参与式激励计划 31.audit n. 审计，稽核，查账 32.auditor n. 审计员，核数师 33.authority n. 职权 34.awkward adj. 难使用的，笨拙的 35.backdates vt. 回溯 36.batch production 批量生产 37.be prone to 倾向于…… 38.behavior modeling 行为模拟 39.behaviorally anchored rating scale（bars）行为锚定等级评价法 40.below contributor 贡献较小的人员 41.benchmark job 基准职位 42.benchmarking n. 【计】基准 43.benefits n. 福利
企业成本控制外文翻译文献(文档含英文原文和中文翻译)
译文： 在价值链的成本控制下减少费用和获得更多的利润 摘要： 根据基于价值链的成本管理理念和基于价值的重要因素是必要的。首先，必须有足够的资源，必须创造了有利的价值投资，同时还需要基于客户价值活动链，以确定他们的成本管理优势的价值链。其次，消耗的资源必须尽量减少，使最小的运营成本价值链和确保成本优势是基于最大商业价值或利润，这是一种成本控制系统内部整个视图的创建和供应的具实践，它也是一种成本控制制度基于价值链，包括足够的控制和必要的资源投资价值的观点，创建和保持消费的资源到合理的水平，具有价值的观点主要对象的第一个因素是构造有利的价值链，从创造顾客价值开始；第二个因素是加强有利的价值链，从供应或生产客户价值开始。因此它是一个新型的理念，去探索成本控制从整个视图的创建和供应的商品更盈利企业获得可持续的竞争优势。 关键词：成本控制，价值链，收益，支出，收入，成本会计 1、介绍 根据价值链理论，企业的目的是创造最大的顾客价值；和企业的竞争优势在于尽可能提供尽可能多的价值给他们的客户，作为低成本可能的。这要求企业必须首先考虑他们是否能为顾客创造价值，和然后考虑在很长一段时间内如何创造它。然而，竞争一直以“商品”（或“产品”）作为最直接的载体，因此，传统的成本控制方法主要集中在对“产品”和生产流程的过程。很显然，这不能解决企业的问题，企业是否或如何能为客户创造价值。换句话说，这至少不能从根本上解决它。 因此，企业必须首先投入足够的资源，以便他们能够创建客户值取向，然后提供它以最少的资源费用。所以在整个视图中对价值创造和提供整体的观点来控制成本，它可以为客户提供完美的动力和操作运行机制运行成本的控制，也可以从根本上彻底克服了传统的成本控制方法的缺点，解决了无法控制的创造和供应不足的真正价值。基于此，本文试图从创作的整体观讨论成本控制提供价值并探讨实现良性循环的策略，也就是说，“创造价值投资成本供应价值创造价值”。 2、成本及其控制的基于价值链理念 2.1基于价值链的成本观念 根据价值链理论，如果企业是要被客户接受，它必须创造和提供能满足其客户的价值。因此，成本（价值或资源支付费用）这不离为创造和提供顾客价值的活动，其活动的价值链。因此，我们应该从价值链角度看成本的重要。
外文翻译 专业机械设计制造及其自动化学生姓名刘链柱 班级机制111 学号1110101102 指导教师葛友华
外文资料名称： Design and performance evaluation of vacuum cleaners using cyclone technology 外文资料出处：Korean J. Chem. Eng., 23(6), (用外文写) 925-930 (2006) 附件： 1.外文资料翻译译文 2.外文原文
应用旋风技术真空吸尘器的设计和性能介绍 吉尔泰金，洪城铱昌，宰瑾李， 刘链柱译 摘要：旋风型分离器技术用于真空吸尘器 - 轴向进流旋风和切向进气道流旋风有效地收集粉尘和降低压力降已被实验研究。优化设计等因素作为集尘效率，压降，并切成尺寸被粒度对应于分级收集的50％的效率进行了研究。颗粒切成大小降低入口面积，体直径，减小涡取景器直径的旋风。切向入口的双流量气旋具有良好的性能考虑的350毫米汞柱的低压降和为1.5μm的质量中位直径在1米3的流量的截止尺寸。一使用切向入口的双流量旋风吸尘器示出了势是一种有效的方法，用于收集在家庭中产生的粉尘。 摘要及关键词：吸尘器; 粉尘; 旋风分离器 引言 我们这个时代的很大一部分都花在了房子，工作场所，或其他建筑，因此，室内空间应该是既舒适情绪和卫生。但室内空气中含有超过室外空气因气密性的二次污染物，毒物，食品气味。这是通过使用产生在建筑中的新材料和设备。真空吸尘器为代表的家电去除有害物质从地板到地毯所用的商用真空吸尘器房子由纸过滤，预过滤器和排气过滤器通过洁净的空气排放到大气中。虽然真空吸尘器是方便在使用中，吸入压力下降说唱空转成比例地清洗的时间，以及纸过滤器也应定期更换，由于压力下降，气味和细菌通过纸过滤器内的残留粉尘。 图1示出了大气气溶胶的粒度分布通常是双峰形，在粗颗粒（>2.0微米）模式为主要的外部来源，如风吹尘，海盐喷雾，火山，从工厂直接排放和车辆废气排放，以及那些在细颗粒模式包括燃烧或光化学反应。表1显示模式，典型的大气航空的直径和质量浓度溶胶被许多研究者测量。精细模式在0.18?0.36 在5.7到25微米尺寸范围微米尺寸范围。质量浓度为2?205微克，可直接在大气气溶胶和 3.85至36.3μg/m3柴油气溶胶。
Optimum blank design of an automobile sub-frame Jong-Yop Kim a ,Naksoo Kim a,*,Man-Sung Huh b a Department of Mechanical Engineering,Sogang University,Shinsu-dong 1,Mapo-ku,Seoul 121-742,South Korea b Hwa-shin Corporation,Young-chun,Kyung-buk,770-140,South Korea Received 17July 1998 Abstract A roll-back method is proposed to predict the optimum initial blank shape in the sheet metal forming process.The method takes the difference between the ?nal deformed shape and the target contour shape into account.Based on the method,a computer program composed of a blank design module,an FE-analysis program and a mesh generation module is developed.The roll-back method is applied to the drawing of a square cup with the ˉange of uniform size around its periphery,to con?rm its validity.Good agreement is recognized between the numerical results and the published results for initial blank shape and thickness strain distribution.The optimum blank shapes for two parts of an automobile sub-frame are designed.Both the thickness distribution and the level of punch load are improved with the designed blank.Also,the method is applied to design the weld line in a tailor-welded blank.It is concluded that the roll-back method is an effective and convenient method for an optimum blank shape design.#2000Elsevier Science S.A.All rights reserved. Keywords:Blank design;Sheet metal forming;Finite element method;Roll-back method
外文文献： Knowledge of the stepper motor What is a stepper motor： Stepper motor is a kind of electrical pulses into angular displacement of the implementing agency. Popular little lesson: When the driver receives a step pulse signal, it will drive a stepper motor to set the direction of rotation at a fixed angle (and the step angle). You can control the number of pulses to control the angular displacement, so as to achieve accurate positioning purposes; the same time you can control the pulse frequency to control the motor rotation speed and acceleration, to achieve speed control purposes. What kinds of stepper motor sub-： In three stepper motors: permanent magnet (PM), reactive (VR) and hybrid (HB) permanent magnet stepper usually two-phase, torque, and smaller, step angle of 7.5 degrees or the general 15 degrees; reaction step is generally three-phase, can achieve high torque output, step angle of 1.5 degrees is generally, but the noise and vibration are large. 80 countries in Europe and America have been eliminated; hybrid stepper is a mix of permanent magnet and reactive advantages. It consists of two phases and the five-phase: two-phase step angle of 1.8 degrees while the general five-phase step angle of 0.72 degrees generally. The most widely used Stepper Motor. What is to keep the torque (HOLDING TORQUE) How much precision stepper motor? Whether the cumulative： The general accuracy of the stepper motor step angle of 3-5%, and not cumulative.
公司英语 -----教育训练部一:常用术语 Hon Hai 鸿海 CMM Component module move 机动组件整合 CEM Contract Manufaction service 合约委托代工 IBSC Internet Business Solution Center 国际互联网应用中心PCEG Personal Computer Enclosure group 个人计算机外设事业群（FOXTEQ） CCBG Connector&cable business group CPBG Competition business group ESBG Enterprise system business group 鸿富锦事业群 SABG system assembly business group 系统组装事业群 NWE Net Work Enclosure NSE Network system enclosure NSG Network system group NFE Network flexible enclosure Foxcavity = HZ = Hong Zhun 鸿准 Stamping tool shop I 冲模一厂 Stamping tool shop II 冲模二厂 Prototype workshop 样品中心 Steel factory 裁剪厂 PCE molding tooling workshop PCE塑模厂 Hua Nan test and measurement center 华南检测中心 MPE mobile phone enclosure MPE MBE mobile phone and notebook enclosure 明塑厂 MGE Alloy magnesium alloy enclosure 镁合金 Engineer standard 工标 Document center (database center)资料中心 Design Center 设计中心 Painting 烤漆(厂) Assembly组装(厂) Stamping 冲压(厂) Education and Training教育训练 proposal improvement/creative suggestion提案改善
智能汽车中英文对照外文翻译文献 (文档含英文原文和中文翻译) 翻译： 基于智能汽车的智能控制研究 摘要：本文使用一个叫做“智能汽车”的平台进行智能控制研究，该小车采用飞思卡尔半导体公司制造的MC9S12DG128芯片作为主要的控制单元，同时介绍了最小的智能控制系统的设计和实现智能车的自我追踪驾驶使用路径识别算法。智能控制智能车的研究包括:提取路径信息,自我跟踪算法实现和方向和速度控制。下文介绍了系统中不同模块的各自实现功能，最重要部分是智能车的过程智能控制：开环控制和闭环控制的应用程序包括增量式PID控制算法和鲁棒控制算法。最后一步是
基于智能控制系统的智能测试。 关键词：MC9S12DG128；智能控制;开环控制；PID；鲁棒； 1.背景介绍 随着控制理论的提高以及信息技术的快速发展,智能控制在我们的社会中发挥着越来越重要的作用。由于嵌入式设备有小尺寸、低功耗、功能强大等优点，相信在这个领域将会有一个相对广泛的应用,如汽车电子、航空航天、智能家居。如果这些技术一起工作，它将会蔓延到其他领域。为了研究嵌入式智能控制技术，“智能汽车”被选为研究平台,并把MC9S12DG128芯片作为主控单元。通过智能控制,智能汽车可以自主移动,同时跟踪的路径。 首先,本文给读者一个总体介绍智能车辆系统的[2、3]。然后,根据智能车辆的智能控制:提取路径信息,自我跟踪算法实现中,舵机的方向和速度的控制。它提供包括了上述四个方面的细节的智能车系统信息。此外,本文强调了智能车的控制过程应用程序包括开环控制、闭环增量PID算法和鲁棒算法。 2.智能车系统的总体设计 该系统采用MC9S12DG128[4]作为主芯片，以及一个CCD传感器作为交通信息收集的传感器。速度传感器是基于无线电型光电管的原理开发。路径可以CCD传感器后绘制收集的数据，并且系统计算出相应的处理。在同时，用由电动马达速度测试模块测量的智能汽车的当前速度进行响应的系统。最后，路径识别系统利用所述路径信息和当前的速度，以使智能汽车在不同的道路条件的最高速度运行。图1示出了智能车辆系统的框图。
外文翻译 原文 Foreign T rade o f China Material Source:W anfang Database Author:Hitomi Iizaka 1.Introduction On December11,2001,China officially joined the World T rade Organization(WTO)and be c a me its143rd member.China’s presence in the worl d economy will continue to grow and deepen.The foreign trade sector plays an important andmultifaceted role in China’s economic development.At the same time, China’s expanded role in the world economy is beneficial t o all its trading partners. Regions that trade with China benefit from cheaper and mor e varieties of imported consumer goods,raw materials and intermediate products.China is also a large and growing export market.While the entry of any major trading nation in the global trading system can create a process of adjustment,the o u t c o me is fundamentally a win-win situation.In this p aper we would like t o provide a survey of the various institutions,laws and characteristics of China’s trade.Among some of the findings, we can highlight thefollowing: ?In2001,total trade to gross domestic pr oduct(GDP)ratio in China is44% ?In2001,47%of Chinese trade is processed trade1 ?In2001,51%of Chinese trade is conduct ed by foreign firms in China2 ?In2001,36%of Chinese exports originate from Gu an gdon g province ?In2001,39%of China’s exports go through Hong Kong to be re-exported elsewhere 2.Evolution of China’s Trade Regime Equally remarkable are the changes in the commodity composition of China’s exports and imports.Table2a shows China’s annu al export volumes of primary goods and manufactured goods over time.In1980,primary goods accounted for 50.3%of China’s exports and manufactured goods accounted for49.7%.Although the share of primary good declines slightly during the first half of1980’s,it remains at50.6%in1985.Since then,exports of manufactured goods have grown at a much
公司英语 -----教育训练部 一:常用术语 Hon Hai 鸿海 CMM Component module move 机动组件整合 CEM Contract Manufaction service 合约委托代工 IBSC Internet Business Solution Center 国际互联网应用中心 PCEG Personal Computer Enclosure group 个人计算机外设事业群（FOXTEQ）CCBG Connector&cable business group CPBG Competition business group ESBG Enterprise system business group 鸿富锦事业群 SABG system assembly business group 系统组装事业群 NWE Net Work Enclosure NSE Network system enclosure NSG Network system group NFE Network flexible enclosure Foxcavity = HZ = Hong Zhun 鸿准 Stamping tool shop I 冲模一厂 Stamping tool shop II 冲模二厂 Prototype workshop 样品中心 Steel factory 裁剪厂 PCE molding tooling workshop PCE塑模厂 Hua Nan test and measurement center 华南检测中心 MPE mobile phone enclosure MPE MBE mobile phone and notebook enclosure 明塑厂 MGE Alloy magnesium alloy enclosure 镁合金 Engineer standard 工标 Document center (database center)资料中心 Design Center 设计中心 Painting 烤漆(厂) Assembly组装(厂) Stamping 冲压(厂) Education and Training教育训练 proposal improvement/creative suggestion提案改善 Technological exchange and study 技术交流研习会 Technology and Development Committee 技术发展委员会 BS Brain Storming 脑力激荡 QCC Quality Control Circle 品质圈
本科生毕业设计（论文）外文翻译毕业设计（论文）题目：悬架系统设计与分析 外文题目：An Overview of Disarray in Active Suspension System 译文题目：主动悬架系统杂谈 学生姓名： XXX 专业：车辆工程1002班 指导教师姓名：田国富 评阅日期：
主动悬架系统杂谈 帕蒂尔，维杰河帕蒂尔，加尼甚 助理教授，机械工程系，A.D.C.E.T，阿什达 摘要：当设计一个悬挂系统时，它的双重目标是尽量减少传到乘客的垂直力量和最大限度地提高轮胎与道路接触以提高操控性和安全性。乘客的舒适性与从车身传递的垂直力有关。这个目标可以通过最小化车身的垂直加速度来实现。过度的车轮行驶，将导致轮胎相对路面的非最佳姿态，从而导致差的操控性和附着力。此外，为了保持良好的操控性，轮胎与路面的最佳接触必须保持在四个轮子上。在传统的悬架系统中，这些特点是冲突的，不符合所有条件。因此，在被动悬架系统的基础上，为了改善主动悬架系统，各种各样的研究工作正在进行中。在本文中各种作品的概述已经完成。考虑到季度汽车模型，本文试图给出关于以往的研究和他们的发现对被动和主动悬架系统的参数。 关键词：主动悬架系统，控制系统，动态，被动悬架，车辆。 1.引言 汽车悬架系统的目的是在不同路况下，能保持良好的操控特性和改善乘坐品质。不同的悬架，满足上述要求的程度不同。虽然，可由设计者的聪明才智来改善，就平均而言，悬架的性能主要取决于悬架使用的类型。按改进的性能可以以升序区分为：与被动，半主动和全主动悬架系统，输入的力通常由液压致动器提供。为主动悬架系统设计的机电致动器的另一种方法将在电子控制和悬架系统之间提供直接接口。 目前，公认的主动悬架有两种形式，一种是制动器和钢板弹簧平行的高带宽主动悬架。第二种是低带宽主动悬架，它的致动器带有一系列的钢板弹簧并且能够控制车身的运动，而簧下质量控制是通过被动阻尼器控制的。汽车悬架的主动控制在传统悬架的基础上又提出了新的改进。主动悬架，包括创建悬挂系统中力的液压致动器。由液压致动器产生的力被用来控制簧上质量的运动，以及簧上和簧下质量之间的相对速度。为了提高车辆的特色，以后将主要对主动悬架的高带宽型进行研究。
204/JOURNAL OF BRIDGE ENGINEERING/AUGUST1999
JOURNAL OF BRIDGE ENGINEERING /AUGUST 1999/205 ends.The stress state in each cylindrical strip was determined from the total potential energy of a nonlinear arch model using the Rayleigh-Ritz method. It was emphasized that the membrane stresses in the com-pression region of the curved models were less than those predicted by linear theory and that there was an accompanying increase in ?ange resultant force.The maximum web bending stress was shown to occur at 0.20h from the compression ?ange for the simple support stiffness condition and 0.24h for the ?xed condition,where h is the height of the analytical panel.It was noted that 0.20h would be the optimum position for longitudinal stiffeners in curved girders,which is the same as for straight girders based on stability requirements.From the ?xed condition cases it was determined that there was no signi?cant change in the membrane stresses (from free to ?xed)but that there was a signi?cant effect on the web bend-ing stresses.Numerical results were generated for the reduc-tion in effective moment required to produce initial yield in the ?anges based on curvature and web slenderness for a panel aspect ratio of 1.0and a web-to-?ange area ratio of 2.0.From the results,a maximum reduction of about 13%was noted for a /R =0.167and about 8%for a /R =0.10(h /t w =150),both of which would correspond to extreme curvature,where a is the length of the analytical panel (modeling the distance be-tween transverse stiffeners)and R is the radius of curvature.To apply the parametric results to developing design criteria for practical curved girders,the de?ections and web bending stresses that would occur for girders with a curvature corre-sponding to the initial imperfection out-of-?atness limit of D /120was used.It was noted that,for a panel with an aspect ratio of 1.0,this would correspond to a curvature of a /R =0.067.The values of moment reduction using this approach were compared with those presented by Basler (Basler and Thurlimann 1961;Vincent 1969).Numerical results based on this limit were generated,and the following web-slenderness requirement was derived: 2 D 36,500a a =1?8.6?34 (1) ? ??? t R R F w ?y where D =unsupported distance between ?anges;and F y =yield stress in psi. An extension of this work was published a year later,when Culver et al.(1973)checked the accuracy of the isolated elas-tically supported cylindrical strips by treating the panel as a unit two-way shell rather than as individual strips.The ?ange/web boundaries were modeled as ?xed,and the boundaries at the transverse stiffeners were modeled as ?xed and simple.Longitudinal stiffeners were modeled with moments of inertias as multiples of the AASHO (Standard 1969)values for straight https://www.doczj.com/doc/d73257257.html,ing analytical results obtained for the slenderness required to limit the plate bending stresses in the curved panel to those of a ?at panel with the maximum allowed out-of-?atness (a /R =0.067)and with D /t w =330,the following equa-tion was developed for curved plate girder web slenderness with one longitudinal stiffener: D 46,000a a =1?2.9 ?2.2 (2) ? ? ? t R f R w ?b where the calculated bending stress,f b ,is in psi.It was further concluded that if longitudinal stiffeners are located in both the tension and compression regions,the reduction in D /t w will not be required.For the case of two stiffeners,web bending in both regions is reduced and the web slenderness could be de-signed as a straight girder panel.Eq.(1)is currently used in the ‘‘Load Factor Design’’portion of the Guide Speci?cations ,and (2)is used in the ‘‘Allowable Stress Design’’portion for girders stiffened with one longitudinal stiffener.This work was continued by Mariani et al.(1973),where the optimum trans-verse stiffener rigidity was determined analytically. During almost the same time,Abdel-Sayed (1973)studied the prebuckling and elastic buckling behavior of curved web panels and proposed approximate conservative equations for estimating the critical load under pure normal loading (stress),pure shear,and combined normal and shear loading.The linear theory of shells was used.The panel was simply supported along all four edges with no torsional rigidity of the ?anges provided.The transverse stiffeners were therefore assumed to be rigid in their directions (no strains could be developed along the edges of the panels).The Galerkin method was used to solve the governing differential equations,and minimum eigenvalues of the critical load were calculated and presented for a wide range of loading conditions (bedding,shear,and combined),aspect ratios,and curvatures.For all cases,it was demonstrated that the critical load is higher for curved panels over the comparable ?at panel and increases with an increase in curvature. In 1980,Daniels et al.summarized the Lehigh University ?ve-year experimental research program on the fatigue behav-ior of horizontally curved bridges and concluded that the slen-derness limits suggested by Culver were too severe.Equations for ‘‘Load Factor Design’’and for ‘‘Allowable Stress Design’’were developed (respectively)as D 36,500a =1?4?192(3)? ?t R F w ?y D 23,000a =1?4 ?170 (4) ? ? t R f w ?b The latter equation is currently used in the ‘‘Allowable Stress Design’’portion of the Guide Speci?cations for girders not stiffened longitudinally. Numerous analytical and experimental works on the subject have also been published by Japanese researchers since the end of the CURT project.Mikami and colleagues presented work in Japanese journals (Mikami et al.1980;Mikami and Furunishi 1981)and later in the ASCE Journal of Engineering Mechanics (Mikami and Furunishi 1984)on the nonlinear be-havior of cylindrical web panels under bending and combined bending and shear.They analyzed the cylindrical panels based on Washizu’s (1975)nonlinear theory of shells.The governing nonlinear differential equations were solved numerically by the ?nite-difference method.Simple support boundary condi-tions were assumed along the curved boundaries (top and bot-tom at the ?ange locations)and both simple and ?xed support conditions were used at the straight (vertical)boundaries.The large displacement behavior was demonstrated by Mi-kami and Furunishi for a range of geometric properties.Nu-merical values of the load,de?ection,membrane stress,bend-ing stress,and torsional stress were obtained,but no equations for design use were presented.Signi?cant conclusions include that:(1)the compressive membrane stress in the circumfer-ential direction decreases with an increase in curvature;(2)the panel under combined bending and shear exhibits a lower level of the circumferential membrane stress as compared with the panel under pure bending,and as a result,the bending moment carried by the web panel is reduced;and (3)the plate bending stress under combined bending and shear is larger than that under pure bending.No formulations or recommendations for direct design use were made. Kuranishi and Hiwatashi (1981,1983)used the ?nite-ele-ment method to demonstrate the elastic ?nite displacement be-havior of curved I-girder webs under bending using models with and without ?ange rigidities.Rotation was not allowed (?xed condition)about the vertical axis at the ends of the panel (transverse stiffener locations).Again,the nonlinear distribu-