6shz-60直聯(lián)式雙吸離心泵的設(shè)計(jì),shz,60,直聯(lián)式雙吸,離心泵,設(shè)計(jì) Pump's outline The pump is the application very widespread general machinery, may say that is place of the fluid flow, nearly has the pump in the work. Moreover, along with science's and technology's development, pump's application domain is expanding rapidly, according to the over-all state statistics, pump's power consumption approximately composes the national total output of electrical energy 1/5, obviously the pump is natural consumes energy the wealthy and powerful family. Therefore, raises the pump technical level to save the energy consumption to have the important meaning. First. Centrifugal pump's principle of work The drive leads impeller revolving through the pump spindle to have the centrifugal force, under the centrifugal action of force, the liquid is flung along the leaf blade flow channel to the impeller export, the liquid sends in after the volute collection the eduction tube. The liquid obtains the energy from the impeller,  causes the pressure energy and the speed can increase, and depends upon this energy the hydraulic transport to the operating location. while the liquid is flung which exports to the impeller, the impeller eye center has formed the low pressure,  has had the differential pressure in the imbibition pot and between the impeller center liquid, in the imbibition pot's liquid under this differential pressure function, after inhales the pipeline and pump's suction chamber unceasingly enters in the impeller. Second, centrifugal pump's structure and main spare part A centrifugal pump mainly by the pump body, the impeller, the packing ring, the rotation axis, the axis seals parts and so on box to be composed, some centrifugal pumps are also loaded with the guide pulley, the inducer, the balance disc and so on. 1. Pump body: Namely pump's shell, including suction chamber and delivery chamber. ①Suction chamber: Its function is enables the liquid to flow in evenly the impeller. ②Delivery chamber: Its function collects the liquid, and sends in it the subordinate impeller or guides the eduction tube, at the same time reduces the liquid the speed, causes the kinetic energy to further turn the pressure energy. The delivery chamber has the volute and the guide vane two forms. 2. Impeller: It is in the centrifugal pump transmits the energy for the liquid only part, the impeller with the bond fixation on the axis, leads revolving along with the axis by the prime mover, passes to through the leaf blade prime mover's energy the liquid. Impeller classification: ①According to liquid inflow classification: Single suction impeller (in impeller's one side has an entrance) and double attracts the impeller (liquid from impeller's lateral symmetry liudao impeller passage). ②Is opposite according to the liquid in centerline's flow direction classification: Runoff type impeller, axial-flow propeller and interflow type impeller. ③According to impeller's structural style classification: Shrouded impeller, open type impeller and semi-opened impeller. 3. Axis: Is transmits the mechanical energy the important components, the  prime mover's torque passes to the impeller through it. The pump spindle is the pump rotor's major parts, on the axis is loaded with components and so on impeller, axle sleeve, balance disc. The pump spindle depending on the both sides bearing supporting, makes the high speed rotation in the pump, thus the pump spindle in a big way wants the bearing capacity, to be wear-resisting, to be anti-corrosive. Pump spindle's material selects the carbon steel or the alloy steel and after the quenching and retempering treatment generally. 4. Packing ring: Is installs in the rotation impeller and the static pump housing (center-section and guide vane's assembly) between packing assembly. It is function is through controls between the two gap method, increases in the pump between the high and low pressure cavity the fluid flow resistance, reduces divulging. 5. Axle sleeve: The axle sleeve is uses for to protect the pump spindle, causes it not to corrode and the attrition. When necessity, the axle sleeve may replace. 6. Axis seals: The pump spindle and around packing box between end cover's installs short for axis to seal, mainly prevents in pump's liquid divulging and the air enters in the pump, achieves seals and prevents the air admission to cause the pump cavitation goal. the axis seals form: Namely has skeleton's rubber seal, the packing seal and the mechanical seal. 7. axial force balancing unit. Third. Centrifugal pump's prime task parameter 1. Current capacity: Namely the pump in unit of time discharges the liquid quantity, usually indicated with the Unit of volume that mark Q, the unit has m3/h, m3/s, l/s and so on, 2. Lifting: The transportation unit weight's liquid (pump suction flange) (pump discharge flange) from the pump inlet place to the pump exit, its energy's increment, indicated with H, the unit is m. 3. Rotational speed: Pump's rotational speed is the pump each minute revolving number of times, expressed with N. Electrical machinery rotational speed N generally about 2900 n/min. 4. Net positive suction head: Centrifugal pump's net positive suction head is expressed that pump's performance's main parameter,  uses the symbolic representation. 5. Power and efficiency: Pump's power input is shaft power P, is also electric motor's output. Pump's output is the active power. Fourth, pump proper energy loss Pump mechanical energy which obtains from the prime mover, has a part to transform into the liquid energy, but another part because in the pump consumes loses. In the pump all losses may divide into the following several items: 1. Hydraulic loss by the liquid in pump impact, the turbulent flow and the surface friction creates. The impact and the eddy current loss are because the liquid flow change direction produces. The liquid flows through the flow channel general meeting which contacts to present the surface friction, from this produces the energy loss is mainly decided by flow channel's length, the size, the shape, the surface roughness, as well as liquid speed of flow and characteristic. 2. Volumetric loss: volumetric loss was already obtained the energy liquid to have a part to flee the result which in the pump the class and leaked outward. Pump's volumetric efficiency is 0.93～0.98 generally. Improves the packing ring and the seal structure, may reduce the leakage, raises the volumetric efficiency. 3. Mechanical loss mechanical loss refers to the impeller lap side and the pump housing friction loss between the liquid, namely the disc loses, as well as pump spindle when packing, bearing and balancing unit and so on mechanical part movement friction loss, generally before primarily. Fifth, pump's speed change--Proportionality law 1. Centrifugal pump's speed change: A centrifugal pump, when its rotational speed change, its rated flow, lifting and the shaft power will have the change according to the certain proportion relations. At present, uses the frequency conversion velocity modulation electrical machinery to realize centrifugal pump's speed change, is a new important energy conservation way. 2. proportionality law expression: In the formula, Q, H, N-- pump's rated flow, lifting and shaft power The subscript 1,2 express the different rotational speed separately n-- rotational speed Sixth, centrifugal pump's ratio rotation Compared to the rotation is the comprehensive parameter which derives by the law of similarity, it is the operating mode function, to a pump, the different operating mode has differently compared to the rotation, for ease of carries on the comparison to the different type pump's performance and the structure, the application optimum condition (the peak efficiency spot) the ratio rotation represents this pump. When chooses the pump, may according to job requirement Q, H and unifies electrical machinery's rotational speed, calculates the ns number, determines pump's type approximately. At that time, used the positive displacement pump generally, at that time, used the centrifugal pump, the interflow pump, the axial flow pump and so on. Seventh,centrifugal pump's cavitation and inspiration characteristic 1.Cavitation phenomenons The pumping station transportation medium's liquid condition and the gas are can transform mutually, the transformed condition is the pressure and the temperature. Under certain temperature, the liquid starts the critical pressure which vaporizes for the vaporization pressure. The temperature is higher, the liquid vaporization pressure is higher. Pump when revolution, if its overflow part local region (for example impeller blade import later somewhere), the liquid absolute pressure drops when pulled out delivers the liquid at that time under the temperature vaporization pressure, the liquid then in this place starts to vaporize, the bubble formation (air bubble internal pressure approximately was equal to vaporization pressure). When these air bubbles along with liquid flow forward motion to high pressure region, down to around the air bubble high-pressured liquid causes the air bubble to reduce suddenly congeals. While air bubble vanishing, the liquid particle by the high speed packing hole, occurs hits mutually forms the intense pressure surge, causes the overflow part to receive the corrosion and the destruction. The above process is called the cavitation. 2. Cavitation will cause serious results: (1). has the vibration and the noise. (2). is influential to pump's operating performance: When the cavitation develops the certain extent, the  steam bubble produces massively, will stop up the flow channel, will cause pump's current capacity, lifting, the efficiency and so on obviously to drop. (3). will have the destruction to flow channel's material quality: Is mainly nearby the leaf blade entrance the metal weary disintegration. 3. centrifugal pump's inspiration characteristic: (1). Pump has the cavitation basic condition is: Under leaf blade entrance lowest liquid flow pressure <= this temperature liquid vaporization pressure . (2). effective net positive suction head: The pump entry (potential head is the entire flood peak which zero) the liquid has subtracts the value which the vaporization delivery head remains only, with expression. (3). pump essential net positive suction head: Liquid flow from pump inlet to impeller in minimal pressure point of force K place complete energy loss, with expression. (4). With and difference and relation: >Pump not cavitation = The pump starts the cavitation < Pump serious cavitation (5). regarding a pump, to guarantee that its safe operation does not have the cavitation, must the net positive suction head also be supposed to add a security allowance regarding the pump, therefore, pump's permission net positive suction head is: = 4. Enhances the centrifugal pump anti-cavitation performance the method to include: (1). I mprovement machine pump structure, reduces, is machine the pump design question. (2). Enhancement installment effective net positive suction head. Most mainly the most commonly used method uses the irrigation inspiration installment. In addition, reduces the inspiration pipeline resistance loss as far as possible, reduces the liquid the saturated steam tension, namely when design inspiration pipeline selects caliber big as far as possible, length short, the bend and valve few, transportation liquid temperature as far as possible low and so on measures, may enhance the installment the effective cavitation remainder. 5. axial force balancing unit (1). axial force production reason ①Around because the impeller the both sides the fluid pressure distributed situation different (wheel cap lateral pressure is low,  wheel disk pressure high) causes axial force A1, its direction for from impeller back side direction impeller eye. ②The fluid flows in and flows out dynamical reaction A2 which impeller's direction and the speed different produce, its direction and A1 are opposite, therefore line shaft directive force A=A1-A2, the direction is ordinary and A1 same (general A2 is small). (2). Axial force balanced ①Uses double attracts the type impeller: The impeller lateral symmetry, the fluid from the both sides inspiration, the axial force automatic counter-balance achieves balanced. ②Opens the balancing hole or installs the compensating pipe: A: Opens several balancing holes in the impeller wheel disk photograph well regarding the induction port place. B: After order to avoid the balancing hole, because the mainstream is disturbed increases the hydraulic loss, may suppose the compensating pipe to replace the balancing hole, namely uses an acorn tube leading-in point pressure to the wheel disk back side. ③Uses the balanced leaf blade: Casts several radial direction muscle piece at the back of the leaf wheel disk, the  muscle piece drives at the back of the impeller in the gap fluid to accelerate to revolve, increases the centrifugal force, , thus causes at the back of the impeller the pressure obviously to reduce. ④Using thrust bearing withstanding axial force. Generally in the small single suction pump the thrust bearing may withstand the complete axial force, prevents the pump spindle to flee moves. Eighth, double suction pump's knocked-down and assemble (first) disintegration step 1、The separation pump housing (1) Demolition shaft coupling pin, is separated from the water pump and the electrical machinery. (2) Dismantles the pump junction plane bolt and the pin, causes the pump cover with the lower part pump body separation, then unloads the stuffing ring. (3) Disassembles with the system has the connection pipeline (for example air conduit, seal water pipe and so on), and with the cloth wrapper good pipe connection, prevents to fall into the sundry goods.after 2, Hangs pump Cover to inspect the above work already completes, then hangs the pump cover. When hoisting up should be steady, and pays attention do not bump with other parts rubs. 3、Hangs rotor (1) And withdraws both sides bearing body gland Matushita. (2) Uses the steel wire to tie up in the rotor both sides stuffing ring place hoisting up, must maintain is steady, is safe. After the rotor hangs, should place on the special-purpose support, and lays aside sturdily. 4、Rotor's disassemblage (1) Dismantles the pump side shaft coupling, takes care of properly connects the key. (2) Loosens the both sides bearing body end cover and takes down the bearing body, then dismantles the bearing fastening nut, the bearing, the bearing end cover in turn and keeps off the hydrosphere. (3) The packing ring, the stuffing ring, the water sealing ring, the padding set and so on takes down, and inspects its attrition or the corrosion situation. (4) Loosens the both sides the axle sleeve nut, takes down the axle sleeve and inspects its attrition situation, time the necessity gives to replace. (5)Inspection impeller attrition and cavitation situation, if can continue to use, then does not will certainly it to dismantle. If must unload firmly time, must use the special pulling force tool to heat up while disassembles, in order to avoid damages the pump spindle. (second) assemble sequence 1、The rotor assemble (1) Impeller to install in the axis correct position, cannot be partial to one side, will otherwise create with pump housing's axial play uneven has the friction. (2) Installs the axle sleeve and screws tight the axle sleeve nut. In order to prevent Shui Shunzhou to leak off, must use the seal rubber or plastic rings between the axle sleeve and the nut to pad. After the assembly, should guarantee that the rubber or plastic rings by the axle sleeve nut is contracted, and nut and axle sleeve already depending on tight. (3) The packing ring, the padding wrap, the water sealing ring, the stuffing ring and keeps off the hydrosphere to install on the axis. (4) Installs the bearing end cover and the bearing, screws tight the bearing nut, then installs the bearing body and is tight the bearing body and the bearing end cover. (5) Installs the shaft coupling. 2、Hangs into rotor (1) To hang steadily into the fore-mentioned attire good rotor module in the pump body.after (2) Takes place the packing ring, the plate moves the rotor, whether there is observes the packing ring to rub, should adjust the packing ring to move the rotor vividly until the plate. 3、Buckle pump cover Fastens the pump cover, tight pump junction plane bolt and both sides bearing body gland. Then, the plate moves the rotor to look whether with before differs from, if does not have obviously exceptionally, then the air conduit, the seal water pipe and so on connects, adds the padding, then, might carry on the antithetical couplet axial organ to adjust. (Third) Decision pump housing junction plane pad's thickness Impeller packing ring after the overhaul has not changed, then the pump housing junction plane's pad takes the original thickness then; If the packing ring has upwardly raises, pump junction plane pad's thickness needed to use to press the lead wire the method to survey. Usually, the pump cover to the impeller packing ring's tight strength is 0-0.03mm. After the new pad completes, after both sides should spread the black white lead, spreads again in the pump junction plane. The attention spreads the white lead to be pure, cannot have the slag lump. Contains in the padding place, the pad must do, certainly must especially carefully cause the pad and the padding contain place the edge even uneven. If the pad is inappropriate, will cause the packing seal, but the massive water leakages, will create doing over. Nine, centrifugal pump's operating procedure 1. Centrifugal pump starts the inspection (1) Electrical machinery overhaul, before connecting the shaft coupling, inspects electrical machinery's rotation direction first to be whether correct. (2) inspection pumps out the inlet line and the attached pipeline, the flange, the valve installs whether to meet the requirement, foot bolt and grounding to be whether good, whether the shaft coupling does install. (3) jigger inspection, rotates whether normally. (4) inspection lubricating oil oil level is whether normal, refuels without the oil, and inspects the lubricating oil (fat) oil material nature. (5) turns on various cooling water valve, and inspects the pipeline to be whether unimpeded. Attention cooling water not suitable oversized or too small, will create the waste oversized, too small, then the cooling performance will be bad. Generally the cooling current of water becomes the striation (6) dozen of pumping's inlet valve, closes pump's outlet valve, and turns on the pressure gauge valve. (7) inspection machine pump's seal condition and oil seal opening. attention: The hot oil pump wants evenly before the start preheating. 2. centrifugal pump's start (1) all operates the inlet valve, closes the outlet valve, the starting dynamo. (2), when the pump outlet pressure is bigger than the service pressure, inspects each work on six cylinders, turns on the outlet valve gradually.when (3) starting dynamo, if the start or has time the unusual sound, should the dump inspection, after eliminating the breakdown, immediately only then starts.when (4) start, pays attention to the human not to face the shaft coupling, by against departs offends somebody. 3. the centrifugal pump stops the pump to operate (1) to close pump's outlet valve slowly. (2) shuts off electrical machinery's power source. (3) closes the pressure gauge valve. (4) parking, cannot stop the cooling water immediately, should pump's temperature only then cut off the water supply falling to 80 degrees below.