Pump a variety of knowledge and maintenance

Pump Category:

The classification of pumps can not be integrated into the working principle and purpose of classification, it will be chaotic. Use is useful, the principle is the principle, different principles of the pump can be used in the same purpose. The same pump can also be used in different places, can be used for different purposes. For example: The mixed flow pump is a diagonal flow pump, which adopts a mixed flow impeller, that is, the liquid flows out of the impeller in a direction inclined to the axis. Axial flow pump its liquid outflow direction parallel to the axis. The classification of a sewage pump, chemical pumps, magnetic pumps, pumps, fire pumps, vacuum pumps, diaphragm pumps, screw pumps, pipe pumps, submerged pumps, reciprocating pumps, colloid mill, water supply and drainage equipment, hydraulic injectors, control cabinets The following lists several as a reference:

1, the first category is based on the principle of work points:

1), vane pump

Vane pumps can be divided into: centrifugal pump, mixed flow pump, axial flow pump, vortex pump.

Centrifugal pump can be divided into single-stage pump, multi-stage pump.

Single-stage pump can be divided into: single suction pump, double suction pump, self-priming pump, non-self-priming pump and so on.

Multistage pumps can be divided into: segmental, volute type.

Mixed flow pump can be divided into the shell and guide vane.

Axial flow pump can be divided into fixed blades and adjustable blades.

Vortex pump can also be divided into single-suction pump, double suction pump, self-priming pump, non-self-priming pump, submersible pump.

2), positive displacement pump

Volume pump can be divided into reciprocating pump, rotor pump.

Positive displacement pump is attached to the working element in the pump cylinder for reciprocating or revolving activities, so that work volume alternately increase and decrease in order to achieve the liquid inhalation and discharge. Reciprocating working elements of the positive displacement pump called the reciprocating pump, for rotary activities known as the rotary pump. The former suction and discharge process alternately in the same pump cylinder, suction valve and the discharge valve to control; the latter is through the gear, screw, leaf rotor or slide and other working elements of the rotation, forcing the liquid from Suction side transferred to the discharge side, sewage pump.

Volumetric pump at a certain speed or reciprocation frequency is inevitable, almost no change with the pressure; reciprocating pump flow and pressure pulsation, the need to use the corresponding reduction pulse method; rotary pump generally no pulsation or only a small Pulsation, diaphragm pump; With self-priming, centrifugal pump, the pump can start pumping the air in the pipe sucked into the liquid; start the pump must be completely open the discharge pipe valve; reciprocating pump is practical for high pressure and low flow ; Rotary pump is used for medium and small flow and high pressure; reciprocating pump suitable for the transmission of clean liquid or gas-liquid mixture, chemical pump. In general, positive displacement pumps are more potent than power pumps.

3), jet pump

Is by the working fluid generated high-speed jet fluid, and then through the momentum exchange and the fluid is injected to increase the energy.

Powered pumps rely on rapidly rotating impellers of liquid on the force, the mechanical energy transfer to the liquid, its kinetic energy and pressure can be increased, and then through the pump cylinder, most of the kinetic energy is converted to pressure and delivery. Power pump, also known as impeller pump or vane pump.

Centrifugal pumps are the most common type of power pump.

Power pump head speed occurs at a certain speed has a limited value, magnetic pump, head with the flow change; work steady, self-priming pump, continuous delivery, flow and pressure pulsation; generally no self-priming, you need to pump first irrigation Full of liquid or pipe pumping only after the beginning of work vacuum pump; wide range of practical performance; suitable for conveying very small viscosity of clean liquid, specially designed pump can transport mud, sewage and other water transport solids. Power pumps are mainly used for water supply, drainage, watering, process liquid transport, power storage, hydraulic transmission and jet propulsion.

4), other classification of the pump

In addition to the principle of pump classification, but also by other means classification and naming. For example, according to the driving method can be divided into electric pump, steam turbine pump, diesel pump and water pump; according to the structure can be divided into single-stage pump and multi-stage pump; According to the use can be divided into boiler feed pump and metering pump; The nature of the liquid can be divided into pumps, pumps and mud pumps

Pump working principle and characteristics

First, the working principle of centrifugal pumps and features

1), centrifugal pump working principle

Before starting the pump, the pump and the inlet pipe are filled with water. After the pump is running, the water in the impeller flow channel is thrown out to the surrounding by the centrifugal force generated by the rotation of the impeller at high speed, and the water is pressed into the volute to form a vacuum at the inlet of the impeller, The water in the pool replenished this space as it was drawn in along the suction pipe under atmospheric pressure. The inhaled water is then thrown out of the impeller by the volute into the outlet pipe. Thus, if the centrifugal pump impeller constantly rotating, you can continuously absorb water, pressure water, water can continue to rise from low to high or far away. In summary, the centrifugal pump is due to the centrifugal force generated by the high-speed rotation of the impeller, the water was raised to the high, it is called centrifugal pump.

2), the general characteristics of centrifugal pumps

(1) The flow direction of water along the centrifugal pump is taken along the axial direction of the impeller, and flows perpendicular to the axial direction, that is, the flow direction of the water flows into and out of each other by 90 °.

(2) Since the centrifugal pump to form a vacuum suction by the impeller inlet, so before starting pump and water pipe must be filled with water, or use a vacuum pump to evacuate the air to form a vacuum, and the pump housing and suction pipe must be strictly sealed, Do not leak, or can not form a vacuum, it can not absorb the water.

(3) Since it is impossible to form an absolute vacuum at the inlet of the impeller, the suction height of the centrifugal pump can not exceed 10 meters. Adding the water loss through the suction pipe, the actual allowable installation height (the pump shaft is far away from the suctioned water) 10 m. If the installation is too high, it will not absorb water. In addition, because the mountainous area is lower than the atmospheric pressure in the plain, the same pump should be installed at a lower altitude when it is installed in the mountains, especially in the high mountains. Otherwise, the water can not be sucked in.

Second, the working principle and characteristics of axial flow pump

1), the working principle of axial flow pump

Axial pumps and centrifugal pumps work on different principles, it is mainly the use of impeller rotation caused by high thrust lift. Axial flow Pump blades lift the water generated by the lift, the water can be pushed from below to above.

Axial flow pump blades are generally submerged in a pool of sucked water. As the impeller rotates at high speed, under the action of the lifting force generated by the blades, the water is continuously pushed upward to make the water flow out of the outlet pipe. The constant rotation of the impeller, the water will be continuously pressured to the height.

2), axial pump general characteristics

(1) water in the axial flow direction of the pump is along the impeller shaft phase inhalation, shaft phase outflow, so called axial flow pump. (2) low lift (1 ~ 13 m), large flow, high efficiency, suitable for plains, lakes, river network drainage.

(3) No irrigation before starting, easy to operate.

Third, mixed-flow pump working principle and characteristics

1), mixed-flow pump working principle

Because the shape of the impeller of the mixed flow pump is between the impeller of the centrifugal pump and the impeller of the axial flow pump, the working principle of the mixed flow pump has both the centrifugal force and the lift force, and the water flows out of the impeller at an angle with the shaft , Through the volute chamber and pipeline to raise water to the heights.

2), the general characteristics of mixed jumped

(1) Francis pump Compared with the centrifugal pump, the lower head, larger flow, compared with the axial flow pump, higher head, lower flow. For plain, Lake drainage.

(2) water flows along the mixed flow pump impeller shaft at an angle between the inhalation and outflow, it is also known as ramp pump.

Fourth, submersible pumps, submersible pump structure, submersible pump works

Submersible pump, also known as submersible pump

Submersible pumps are a versatile water treatment tool that can see the submersible pump in both agricultural and industrial processes. According to their applications and uses can be divided into sub-sewage pumps, sand submersible pumps, water submersible pumps.

Submersible pumps are generally composed of a pump body, a suction pipe, a pump seat, a submersible motor and a starting protection device. Popular to talk about is a combination of pump and motor transport liquid machinery, its simple structure, easy to use.

According to the relative position of the pump and the motor, the submersible pump can be divided into pump and pump.

1, the pump on the pump submersible pump, the motor below, this structure greatly reduces the radial size of the pump, so much for submersible pumps and submersible pump with small jobs.

2, under the pump submersible pump motor above, the pump below, it is divided into two types of built-in and exterior.

â‘´ Built-in submersible pump Submersible pump delivers the liquid first through the annular flow path surrounded by the motor, so that the cooling motor and then out of the pump pressure outlet. This pump even in the case of drained suction sump, but also do not have to worry about motor heating, so the scope of application is expanding.

⑵ external pump submersible pump directly from the impeller behind the pressure chamber or guide vane outlet liquid discharge, the motor is also pumped liquid cooling. Because the pump structure can work in the lighter liquid, it is often used in the submersible pump, especially it is the main structure of large-diameter submersible pump

(3) The mechanical seal of the submersible pump is located in the high pressure area of ​​the outlet water flow. The higher the head is, the higher the water pressure is. Therefore, the performance of the mechanical seal is controlled by the lift.

Fifth, the use of pipe pump precautions and their characteristics

1, the pipeline pump in operation, the bearing temperature can not exceed the ambient temperature 35C, the maximum temperature shall not exceed 80C.

2, to the pipe pump bearing body bearing lubrication oil, observe the oil level should be at the oil center line, the lubricating oil should be promptly replaced or added.

3, Unscrew the diversion plugs of the pipe pump body, pour water (or cited pulp).

4, move the pump motor pipe, try to see the motor steering is correct.

5, close the pipeline pump outlet pipe valve and outlet pressure gauge and import vacuum gauge.

6, start the pipeline pump motor, when the normal operation of the pipeline pump, open the outlet pressure gauge and import vacuum pump, depending on their display of appropriate pressure, and gradually open the gate valve, while checking the motor load conditions.

7, Try to control the flow and lift of the pipeline pump within the range indicated on the plate, in order to ensure that the pipeline pump in the highest efficiency point of operation, in order to get the maximum energy saving effect.

8, pipeline pump to stop using, first close the gate valve, pressure gauge, and then stop the motor.

9, found that there is an abnormal sound pipe pump should stop immediately check the reasons.

10, check the pipeline pump and pipe joints with loose phenomenon. Turn the pipe pump by hand to see if the pipe pump is flexible.

11, Regular inspection of pipeline pump sleeve wear, wear larger should be promptly replaced.

12, pipeline pump in the first month of work, after 100 hours to replace the oil, after each 500 hours, oil change time.

13, long-term deactivation of the pipeline pump, pipeline pump required to be all open, dry the water, the rotating parts and joints coated with grease installed, properly preserved.

14, pipe pump used in winter season, after parking, the need to unscrew the lower part of the pump plug screw the media to the net, to prevent cracking.

15, often adjust the pipe pump packing gland to ensure normal indoor drip leakage.

Sixth, the routine maintenance of the pump

1. Purpose

Make sure the pump is always in good running or standby condition.

2, the scope of application

All buildings installed life pumps, fire pumps, spray pumps, booster pumps, sewage pumps, air conditioning pumps.

3, responsibility

Maintenance by the management office is responsible for regular maintenance of the pump.

4, the content

1), daily life pump and air conditioning pump daily inspection and maintenance, once every six months to conduct a comprehensive maintenance.

2), fire pump and spray pump every month, booster pump test run once every February, the running time of 10-15 minutes, fire pump start fire hydrant at the top of the test tube outlet spray range of 6M or more, every six months Conduct a comprehensive maintenance.

3), sewage pumps, submersible pumps every six months to conduct a comprehensive maintenance.

4), Pump maintenance should be connected with the pump body within 2 meters of valves, pressure gauges, pipes and other maintenance with the pump at the same time.

5), the pump body care

â‘´ check the pump should be intact, the nameplate intact, clear and clear direction of the water flow direction, clean and tidy appearance, paint intact.

⑵ add oil, if the oil discoloration, impurities, should be replaced.

⑶ check the packing seal, if leakage should be added or replaced asbestos rope filler.

â‘· coupling coupling bolts and rubber pads if damaged should be replaced.

⑸ fastening screws and rust-proof handle.

⑹ life pumps and air conditioning pumps due to frequent operations, the bearings should be open at both ends of the shaft to be cleaned or replaced each year.

6), motor maintenance

â‘´ appearance inspection should be neat, nameplate intact, ground wire connection is good.

⑵ open the motor junction box wire connector, with 500V megger test motor winding phase and phase, the relative insulation resistance value should not be less than 0.5 megohm.

⑶ motor terminal box wiring and the three-phase conductors should be firmly and tightly.

7), related valves, piping and accessories maintenance

â‘´ each valve switch should be flexible and reliable, no leakage inside and outside.

⑵ check valve action should be flexible, no leakage inside and outside the valve body.

⑶ pressure gauge indicates accurate, clear dial.

â‘· pipes and accessories look clean and beautiful appearance, no cracks, the paint should be complete without loss.

⑸ point to determine whether the correct pump steering, if correct, should be corrected.

8), control cabinet maintenance

â‘´ disconnect the control cabinet total power, check the switch, start, stop button action should be flexible and reliable.

⑵ check the cabinet air switch, contactors, relays and other electrical equipment is intact, tighten the electrical contact with the wiring terminals and wiring terminals screws.

⑶ clean dust inside and outside the control cabinet.

â‘· close the total power, check the power indicator should be normal.

9), maintenance start pump, observe the ammeter, indicating light is normal.

10), observe the pump operation should be smooth, no significant vibration and noise, pressure gauge indicates normal, the control cabinet appliances no bad noise.

5, the main pump maintenance projects

SB single suction centrifugal pump maintenance projects and requirements

Operating requirements and technical requirements

1), check stuffing box

When using the stuffing box seal, the pump must pay attention to the tightness of the packing. Too much loose water will affect the performance too much. In normal times, the water leakage should be about 60 drops per minute, the dripping water should be normal and the water splashing around is not normal

2), check the mechanical seal

The mechanical seal in the pump, should not operate under the condition of water cut, debugging can only be used for instant momentary movement, the mechanical device in normal operation will have a small amount of dripping out of the retaining ring outflow, when the leakage is more, you should check Friction ring, overhaul or replacement of the mechanical seal Under normal circumstances, the life of 8000 hours, generally do not have to replace the entire package as long as the ring can be swapped ring and the ring can be a pair of friction ring

3), lubricating bearings

The pump imported SKF series of semi-enclosed bearings, the factory has been raised temperature grease, can be run continuously for 2 years, the annual need to add grease once a year

4), check the impeller to clean foreign objects

In case of special circumstances, pump impeller damaged or rolling into the foreign body, need to check the clean-up, you need to remove the bearing body and the tail cover, pulled out to the rear shaft and impeller, pump and inlet and outlet without having to move

5), check wearing parts

The main wearing parts of the pump include flexible couplings, mechanical seals, static and dynamic rings, O-shaped rubber rolls, bearings, impeller nuts, packing plates, etc. Careful inspection should be taken for maintenance.

Seven, submersible sewage pump maintenance and repair

Due to the particularity of the submersible sewage pump working environment, in order to ensure the normal use and life of the submersible sewage pump, regular inspection and maintenance should be carried out:

1, replace the seal ring: After long-term use in the sewage medium, the gap between the impeller and the seal ring may increase, resulting in reduced pump flow and efficiency, turn off the brake, the pump hoisted, remove the bottom cover, remove Seal ring, according to the actual size of the impeller ring with seal ring, the gap is generally about 0.5mm.

2, submersible sewage pump long-term need, should be cleaned and lifted in ventilated and dry place, pay attention to antifreeze. If placed in water, run at least 30 min every 15 days (do not dry) to check its function and suitability.

3, cable inspection at least once a year, if damaged please give replacement.

4, at least once a year inspection motor insulation and fastening screws, if the motor insulation down to find someone to repair, if the fastening screws loose, please re-tighten.

5, submersible sewage pump at the factory has injected the right amount of oil, used to lubricate the mechanical seal, the oil should be checked once a year. If you find water in the oil, it should be let go, replace the oil, replace the gasket, tighten the screw plug. After three weeks, it must be rechecked. If the oil becomes emulsion, the mechanical seal should be inspected and replaced if necessary.

6, submersible sewage pump operation failure, according to the given troubleshooting methods are excluded, if still can not be resolved, and can not determine the cause, do not indiscriminately disorganized chaos repair, should immediately find someone to repair.

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