09月22日, 2014 98次
Equipment maintenance directory, pump gas purification (a), definition and classification of the pump (two), treatment plants use pump structure, working principle, maintenance and the common faults of centrifugal pump reciprocating pump metering pump, 5 screw pump, gear pump(three), pump daily maintenance and repair program (a), the definition and classification of the pump, the pump is the original motive of the mechanical energy is converted to liquid energy machine. The original motivation (motor, diesel engine etc.) drives the impeller to rotate through shaft, to do work on liquid, so the energy (including potential energy, pressure energy and kinetic energy) increases, so that the liquid delivery requirements to high pressure or place. • pump is a kind of general machinery important, products are widely used in industry, agriculture. Industry is mainly applied to the field of thermal power, nuclear power, petroleum, petrochemical, city water supply, environmental protection etc.. In many species, pump, classification method, it also each are not identical, according to its working principle can be divided into three categories: vane type pump, positive displacement pumps, other types of pumps. We now according to the structure, medium, use comprehensive classification, see table(two), treatment plants use pump structure, working principle, maintenance and common fault • 1, centrifugal pump centrifugal pump is the basic structure composed of six parts are the impeller, pump body, pump shaft, bearings, seal rings, stuffing box. Impeller centrifugal pump is the core part, its higher speed, the impeller blades and played a major role in the assembly before, the impeller through the static equilibrium experiments. Internal and external surface of impeller on the requirements of smooth, to reduce the flow friction loss. Also known as pump pump shell, which is the main water pump. Play a role in supporting fixed, and is connected with the installation of the bearing bracket. The role of pump shaft coupling and motor by connecting, the motor torque to the impeller, it is the transmission of mechanical energy of the main components. Is a set of bearings component on the support shaft in the shaft, a rolling bearing and sliding bearing two. Rolling the use of butter as a lubricant oil to be appropriate is 2/3 3/4 size too much may have a fever, and too little heat and noise!e799bee5baa6e58685e5aeb931333335326161 Sliding bearings using a transparent oil as lubricant, fuel to the oil level line. Too much oil to be leaking along the shaft and drift of base, too little overheated bearings burned to the accident! Bearing in the pump during operation the maximum temperature of 85 degrees in the general run of about 60 degrees, if we should find the reasons for higher (whether there are impurities, oil is black, is water) and timely treatment.Also known as reduced leakage sealing ring ring. Impeller and pump shell gap between the pump pressure will cause the water flow through the gap area of low pressure water pump, effect, efficiency! The gap is too small will cause the impeller and the pump shell friction and wear. In order to increase the return to reduce the internal leakage resistance, the service life of delaying the impeller and the pump shell, junction with sealing ring in the pump impeller shell edge and foreign aid, sealing the gap remained at between 0.25 ~ 1.10mm is appropriate. Stuffing mainly by the packing, seal ring, tube filler, filler cap, seal tubes. Fill the role of letter is to close the gap between the pump shell and a pump shaft, not to pump the water flow out to not let the outside air into the pump. Always maintain the vacuum pump! When the pump shaft and the packing heat friction depends on the water pipe on the living water to fill the cooling water sealed circle! To maintain the normal operation of pumps. So in the operation process of pump in the inspection tour of inspection of the stuffing is the special attention should be paid to! On the packing should be replaced in about 600 hours to runCentrifugal pump working principle: when the centrifugal pump, pump shaft to drive the impeller to rotate quickly, forcing the pre filling rotating liquid in leaves, in the inertial centrifugal force, the liquid from the impeller center outward radial motion. Liquid obtained energy during the motion process flows through the impeller, pressure can increase, the increase of flow rate. When the liquid from the impeller to enter the pump shell, and deceleration due to shell channel expands gradually, part of kinetic energy into pressure energy, the final discharge pipe along a tangential flow. So the volute is not only from the impeller outflow liquid components, but also a turning device. When the liquid from the impeller center swing outward to form a low pressure area, the center of the impeller, the total potential energy surface and the center of the impeller tank under the difference, thus the liquid is sucked into the center of the impeller. Relying on the continuous running impeller, the liquid will be continuously suction and discharge. The mechanical energy of liquid in the centrifugal pump performance for the ultimate pressure can improve.It should be stressed that, if the pump before the start should be filled with liquid to be delivered to the pump shell, because the air density is low, the centrifugal force produced by the rotation of the impeller, the impeller center area is not enough to form a suction pressure liquid storage tank, so although the centrifugal pump can not transport liquid. This shows that the non self priming centrifugal pump, this phenomenon is called gas. Suction piping installation check valve is to prevent before the start into the pump shell liquid flows out from the shell. Air from the suction pipe to cause gas tied all the pump casing. 望采纳！！！ 本回答由提问者推荐
Natural gas cleaning equipment maintenanceContents1. Pump1.1 Pump definition and classification1.2 Treating factory’e69da5e6ba907a686964616f31333335326162s pump structure, operating principle, maintenance, repairing and common fault1.2.1 Centrifugal pump1.2.2 Reciprocating pump1.2.3 Metering pump1.2.4 Screw pump1.2.5 Gear pump1.3 Pump routine maintaining and repairing procedure 1.1 Pump definition and classificationPump is a machine transforming prime motor’s mechanical energy to liquid’s energy. Prime motor(electromotor, diesel engine, etc.) rotates impeller through pump spindle to power liquid so that its energy (including potential energy, pressure energy and kinetic energy) increases to convey the liquid to higher place or where pressure is needed.Pump is an important general machinery. It is extensively used in the fields of industry and agriculture. In industry it is mainly used for thermal power generation, nuclear power, petroleum exploitation, petroleum chemical, city water supply and environmental protection etc.Pump has many types and its classifying method is various. By its operating principle it can be divided into three catalogues: vane pump, volume pump, and other pumps. The following table is a general classification based on structure, media and usage. 1.2 Treating factory’s pump structure, operating principle, maintenance, repairing and common fault 1.2.1 Centrifugal pumpCentrifugal pump is mainly formed by six parts: impeller, pump body, pump spindle, bearings, sealing rings and stuffing box. Impeller is centrifugal pump’s core part with high rotating speed and strong force. The vanes on the impeller play a main role. Before assembly, impeller must pass static balance test. Impeller’s inner and outer surface should be smooth to decrease water flow’s frictional loss. Pump body is also called pump casting. It is pump’s main body with function of supporting and fixing and connecting with bearing bracket. Pump spindle is connected with motor through coupling and transmits motor torque to impeller. So it is main part of mechanical energy transmitting. Bearing is a component sheathing pump spindle to support it, including antifriction bearing and sliding bearing. Antifriction bearing uses tallow as lubricant. The tallow refill should be proper, normally 2/3 ~ 3/4 of volume. Too much can cause heating and too less cause noise and heating. Sliding bearing uses clean oil as lubricant. Oil refill should be to oil level line. Too much oil will ooze out along pump spindle and splatter; too less will overheat and cause accident. The bearing maximum temperature in pump operation is850C and normally around 600C.If it is too high, must look for reasons (if there is impurity, oil becomes black, or water seep in) and solve it in time. Sealing ring is also called leaking-reducing ring. Too big gap between impeller inlet and pump casting will cause water flows from high pressure area to low pressure area through this gap, affecting water yield and lower efficiency; too small gap will cause abrasion between impeller and pump casting. To increase backflow resistance and decrease inner leaking and lengthen impeller’s and pump casting’s lives, sealing ring is assembled on the joint of pump casting inner surface and impeller outer surface. Sealing gap 0.25 ~ 1.10mm is best. Stuffing box is consisted of stuffing material, water-sealing ring, stuffing trunk, cover and water-sealing tube. Stuffing box’s main function is sealing the gap between pump casting and pump spindle to prevent water inside pump flowing out as well as outside air flowing in so that the pump is kept vacuum inside all the time. When friction of pump spindle and stuffing material produces heat, the water will go through water-sealing tube to water-sealing ring to cool down stuffing material so that pump can work normal. So special attention must be paid to stuffing material during itinerant inspection in pump operation. Stuffing material must be replaced after about 600h working. Centrifugal pump operation principle: after started, pump spindle drives impeller together to rotate in high speed, the pre-filled liquid is compelled to rotate among vanes, under inertial centrifugal force, the liquid starts radical motion from impeller center to periphery. The liquid gets energy when flowing through impeller, static energy and flowing rate increase. After left impeller, the liquid enters into pump casting, since flowing way becomes wider and wider, flowing rate decreases and part of kinetic energy transforms to static energy, at last it flows into outlet tube along tangential. So pump casting is not only the place of accumulating liquid flowed from impeller but also a energy-transforming device. When liquid was tossed from impeller center to periphery, impeller center becomes low pressure area, liquid will be absorbed into impeller center under the total potential energy difference of storage surface and impeller center. With impeller’s continuous rotating, liquid is absorbed in and tossed out continuously. The mechanical energy acquired by the liquid in centrifugal pump finally becomes increased static energy. It is needed to emphasize that before centrifugal pump starts, liquid should be fully filled into pump casting. Because air density is small, centrifugal force produced after impeller rotates is small, impeller center cannot form low pressure needed to absorb liquid to storage, so even though centrifugal pump starts, it cannot convey liquid. This shows centrifugal pump has no self-absorbability. The phenomenon is called air bind. Installing of one-way bottom valveto absorbing tubeway isto prevent liquid from flowing out before starting. Airentering into pump casting through absorbing tubeway can cause air bind.
introduction of metal materialsmetal materials are most widely used in our daily lives and industrial uses.there are several categories of metal materials including steel, iron ,nonferrous material etc.and steel is the most commonly used among them. iron is the main element in steels,other elements including all kinds alloy elements added and foreign elements.the vast varieties in the properties of steel are due to the differences of these alloy elements regarding categories and percentage.such as ordinary carbon steel ,stainless steel, alloy steel etc.carbon is playing an indispensable role in the functioning of the alloy elements.iron makes up the majority percentage in all kinds of steels.several alloy elements can be mostly seen in the steel such as carbon(c),silicon (si), manganese(mn),phosphorus(p),sulfur(s),chromium(cr),nickel(ni),molybdenum(mo),titanium(ti) ,vanadium(va) etc.often we see phosphorus and sulfur as foreign substances,the less percentage these two elements make up the higher quality the steels are.steel can be simply classified into three categories in accordance with the alloy elements added to it as: carbon steel,alloy steel, stainless steel.carbon steel is the kind with only the alloy elements of c,si, mn,p,s,and can be categorized according to the percentage p and s are making up as :ordinary carbon steel(p and s each less than 0.04%) like:Q215A, Q235BF and high quality carbon steel(p and s each less than 0.03%) like:20#,45#,16Mn etc.alloy steel also contains elements cr,mo,v with less than ten percent in addition to the five ordinary elements above mentioned.stainless steel:with a as high as 20 percent percentage of alloy such as cr,ni,etc added.for example:in japan and the united states:304(C<0.08%；e68a84e799bee5baa6e79fa5e9819331333335326130 Cr~18%； Ni~9%) 316(304 + Mo(~2.5%)in china0Cr18Ni9(C≤0.08%；Cr~18%；Ni~9%)L360:pipe steel,L is the symbol of tensile strength .so here the meaning is tensile strength 360mpa .it is mainly used for spiral-welding pressure pipeline with elements :0.08～0.12C, 0.10～0.25Si, 1.10～1.30Mn, ≤0.015P, ≤0.008S, 0.03～0.05Nb.models such as: L360QS seamless steel pipe and L360MS longitudinal submerged arc welding pipe.deformation method:uoe is a physical deformation method to produce steel pipes from the steel plates.20G:(changed to Q245R in 2008)one kind of steel .mainly used in vessels.G is the first letter of the word vessel spoken in mandarin as”guo “ specification should be referred to as”GB713-1997,applicable extent :steel plates with the thickness from 6mm to 150mm.nondestructive testing is in accordance with JB/T4730.3-2005(including three different degrees).20G mechanical properties: tensile strength:410-550 mpa. yield strength:235-245mpa .elongation:20%the difference between20# and 20G except sharing the same carbon content:some rare elements are contained in 20G which better the steel to be used in pressure vessels.and 20G is often judged by its mechanical properties like:bend,impact and tensile strengths.20# steel:C—(0.17～0.24)% Si—(0.17～0.37)% Mn—(0.35～0.65)% P—≤0.040% S—≤0.040%.mechanical properties:yield strength:more than 250mpa,tensile strength:more than 420mpa,elongation:more than 25%,reduction of area:more than 55%,impact toughness:none,hardness:156HBS under the condition of hot rolling.16mn: mainly used as forges,chemical compositionC ：0.13～0.19 Si :0.20～0.60 Mn :1.20～1.60 Cr ≤0.30 P≤0.030 S≤0.020 Ni≤0.30 Cu≤0.25 forged 16mn mechanical properties:nominal wall thickness:less than 300mm.heat treatment :nominalizing then tempering with the tempering temperature over 600 celsius.mechanical properties:tensile strength:450-600mpa ,yield strength:over 275mpa ,elongation:20%.impact test:test temperature:0 celsius.impact toughness:over 31 , brinell hardness:from 121 to 178 本回答由提问者推荐
还是找专业人员吧
太多了，，，，。。
Born as a VIP, dead also for models,Keith, xiang yu has refused to river-crossing eastward. 本回答由网友推荐
要根据实际意思翻译。中文意思就是说，知无论生死都要是个顶天立地的真英雄汉子，因道为像项羽一样失败了，没有脸面回家乡面内对父老相亲。No matter dead or alive,we should be a hero.For my failure i do not dare to come back.当然我的翻译很粗糙，没有仔细润色，你自己其实容可以翻译得更好
Born as a VIP, dead also for models,Keith, xiang yu has refused to river-crossing eastward。古文古词其知实道翻译是很困难的，这专只是生属译。。
Health as the outstanding personality, death is also a male ghost.Keith, xiang yu has refused to river-crossing eastward.希望抄对你袭有帮知助。道
不得不佩服一下LS的翻译……尤其是前两句……= =||||……orz……
Health as the odds, death is also a male ghost,So far thinking Xiang Yu refused to have River.
The specific situation is this: yesterday I have sent email to ship company booking, today the factory told packing list information wrong, party number changed. Now I need to send mail to booking, and explain the reason. General meaning is as follows: because I the factory to provide copies of packing list before information is wrong, I enclose updated booking, please provide housing paper as soon as possible. 希望能帮到您，我建议您zhidao以后想翻译可以直接去有道，百度搜有道，第一内个就是，不用等大家帮您。容节省时间吗。 本回答由提问者推荐
摩擦7a64e4b893e5b19e31333330363136与润滑 摩擦与润滑 迄今为止，在许多问题的学生已被忽视或忽略了摩擦。 到目前为止，在许多问题的处理，学生们被告知不包括在摩擦或忽略摩擦。 其实，摩擦到一定程度时，两个部分是相互接触和移动。 事实上，当的接触和相对运动的两部分的总量，以产生一定的摩擦。 术语摩擦是指两个或多个部分的阻力的运动。 边界摩擦取决于两个或多个部件之间的相对运动的程度梗阻。 摩擦是有害的或有价值的根据在哪里发生。 根据不同的位置上时，所产生的摩擦可能是有害的，并可能是有益的。 摩擦是必要的紧固装置如螺钉和河流取决于摩擦按住拉链和部分组合在一起。 摩擦锁定装置，必须存在，，如丝杆副与河流，依靠摩擦力保持锁定状态，使这些设备各部分连接在一起。 带驱动程序，刹车和轮胎的摩擦是必要的其他应用程序。 摩擦带传输中的应用例的，制动器，轮胎是必需的。 在一台机器上的移动部件的摩擦是有害的，因为它降低了该装置的机械优势。 的摩擦力所产生的机器的运动部件是有害的，因为这会降低该装置的机械效率。 通过摩擦产生的热损失的能量，因为没有工作发生。 所产生的热量的摩擦和损耗的??能量，因为它是不采取行动。 此外，更大的功率需要克服的摩擦加剧。 此外，存在需要大量的能量来克服摩擦力的增长。 热是破坏性的，因为它会导致扩张。 所造成的热膨胀变形是破坏性的。 扩展可能会导致轴承或滑动面，以适应更严格。 热膨胀可能是更严格的轴承或滑动面。 如果足够大的压力，因为扩张，建立了轴承扣押或冻结。 的热膨胀所造成的压力变得足够大时，轴承可能停止运动，即使烧结。 此外，作为热开发，从低温材料制成的轴承可能会熔化。 另外，作为增加的热量，可以通过低温工作的轴承材料熔化。 有三种类型的摩擦在移动部件上，必须加以克服的： 的运动中的对象的存在下所必须克服的摩擦力三种类型的： （1）开始，（2）的滑动，和（3）轧制。 静摩擦，滑动摩擦，3，滚动摩擦 起动摩擦是两种固体倾向于抵抗运动之间的摩擦。 静摩擦是在两个相互其他移动的物体之间产生的摩擦力的限制。 当两个部分是在静止的状态中，两个零件的表面凹凸往往互锁，并形成一个楔作用。 当在静止状态下的两部分的两个表面，不规则的形状，使它们产生的相互锁定，并生成一个楔形作用。 在这些部位，以产生运动的楔形固定表面的峰和谷，必须作出滑出，并且彼此。 产生运动，在两部分的过程中，在固定表面的楔形尖端和凹槽必然单独的表面相互滑动进出。 的两个表面粗糙的，更大的是他们的运动产生的起动摩擦力。 两个表面越粗糙，由它们引起的静摩擦力的力也更大。 由于通常没有固定的模式之间的波峰和波谷两部分组成，违规行为不联锁，一旦零件议案，但在彼此的幻灯片。 由于不规则表面通常不固定的前端和两个配合表面的凹部的形状，一旦发生相对运动将不再被互锁。 被称为两个运动部件的摩擦的滑动摩擦。 的两个运动表面之间的摩擦是指作为一个滑动摩擦。 如图所示于Fingure1，起动摩擦总是大于滑动摩擦力。 如图1中所示，在静态摩擦力总是大于滑动摩擦。 滚动摩擦发生时，受到磨辊装置的巨大压力，导致改变形状的零件或变形。 滚动摩擦产生一个滚动的设备受到巨大的压力，导致零件变形。 在这些条件下，在前面的辊的材料堆积的倾向，并迫使对象滚稍微上坡。 的滚动部件的前部产生的物质的积累，和在这种情况下，产生一个力，以在相反的方向滚动，以使该对象。 这种变化的形状，被称为变形，使分子的运动。 这被认为是作为弹性变形的形状的变化，引起的分子之间的相对运动。 其结果是，产生的热量从增值所需的能量，以保持部件转动并克服摩擦。 其结果是，需要额外的能量以保持的部件的旋转，以克服摩擦，和由此产生的热。 的摩擦引起的表面不规则性的楔入作用是可以克服的部分由表面的精密加工。 的摩擦所造成的不规则表面的楔形作用，克服的部分的表面，通过机器的准确性。 然而，即使这些光滑的表面，可能需要在它们之间的物质的使用，以减少摩擦还更。 然而，即使是这样一个表面光滑的表面之间仍然充满了一些物质，以减少摩擦。 这种物质是通常的润滑剂，提供了一个很好的，薄的油膜。 这种物质通常是能够生成细的层和薄膜的润滑剂。 电影表面除了保持密切接触，产生热量，并防止表面的结合力。 该膜保持2的表面分离，并通过的紧密接触和产生的热量，以提供粘合性。 补充问题：以减少摩擦的另一种方式是，使用不同的材料的轴承表面和旋转部件。 减少摩擦的另一种方式是使用不同的材料，以使表面的轴承及滚动件。 这就解释了为什么青铜轴承，软合金和铜，并在使用oilite轴承与柔软和硬化的钢轴。 这就解释了为什么铜牌，软合金和铜自润滑轴承钢轴用柔软的表面上坚硬的表面上。 oilite轴承是多孔的。因此，当轴承被浸渍在油中，毛细作用进行的油通过轴承的空间。 多孔自润滑轴承。在响应于此，当轴承浸渍在该油，油将通过毛细作用填充在轴承中的孔。 这种类型的轴承都带有其自己的润滑剂，其中的压力是最大的点。 这种类型的轴承能够释放它自己的存储的润滑油的压力的最大位置。 运动部件的润滑，减少摩擦，磨损和发热。 润滑的运动部件是可能的，以减少摩擦，磨损和产生的热量。 最常用的润滑剂，油，油脂，和石墨化合物。 最常用的润滑剂是油，油脂，和石墨复合材料。 润滑油服务于不同的目的。 在不同条件下使用不同的润滑油。 两个运动表面是在何种条件下工作，确定要使用的润滑剂散发了润滑剂的选择和系统的类型。 两个移动面的工作决定系统润滑油和布。 最小的压力对速度慢的可移动部件，油槽分发所需的润滑油量彼此上移动的表面通常是足够的。 会员的低速轻负载运动，润滑剂槽的通常是在表面的相对运动，以提供足够的润滑。
The packing list that my factory provided earlier was incorrect, so please see the attached booking that has been updated. Please provide us with warehousing paper a.s.a.p.
Because the packing list which our factory provide before have wrong informations, we enclose the updated booking. please provide housing paper for us as soon as possible.可以嘛zd，回满意？答
As there is something wrong with the packing slip we provided previous, now we enclosed updated booking, please provide warehousing paper at your earliest time.
Your response has been recieved. Thank you.Given the fact that the budget of our company has been set this time, can we pay the rest 900 EUR off in next order?Your response is appreciated. 本回答由提问者推荐
we have received your reply, thank you.Because our budget has been approved, Could you tell me whether we can pay the price spread 900 EUR in the next order? Looking forward to your reply.