Maintenance and repair of chemical process pumps

How to maintain the chemical pump?

Conscientiously implement daily inspections, inspect once every six hours according to the operating conditions, observe and measure the sound, temperature and appearance based on the five senses, add lubricating oil in an appropriate amount, accurately determine the operating status of the equipment, and keep records. To prepare for the review and verification of the handover.

If there is an abnormal sound or the temperature is too high, consult with the operator in time, or find the technician on duty to test, make a maintenance and inspection plan, and replace the spare equipment if necessary, so as to conduct in-depth inspection of the equipment in operation and deal with it in a timely manner. And keep a good record.

Chemical pump daily damage

Generally summarized in the following points:

1. Damage to the elastic block of the shaft coupling: Due to the impact of operating torque, friction, and temperature rise, the elastic block is damaged, the equipment vibrates greatly, there is abnormal sound, accompanied by knocking sound, it should be replaced in time, otherwise it will cause shaft coupling Breaking, causing the equipment to stop suddenly, delaying production, if the metal of the shaft coupling flies out of the protective cover, there will be a safety hazard.

2. Lubricating oil loss: In daily operation, the equipment has been running at high speed and high temperature, and the wear of the bearings will cause the normal loss of lubricating oil. Therefore, it is necessary to add lubricating oil in a certain amount of time. The amount of lubricating oil is determined by the lubricating oil detection hole of the equipment. It should not be too high or too low. The oil level should be kept below one-half of the scale line of the sight glass and above one-third of the scale line to be the standard oil. bit.

3. Wear of the impeller: Due to the impact and wear of the material during operation and the corrosion of the material, the blades of the impeller are worn. After wear and tear, it will affect the working rate of the equipment, resulting in too low pressure and flow, which cannot meet the required process parameters. The impeller must be replaced. When replacing, you can choose to use the backup equipment to reduce downtime and not delay the overall production demand.

4. Bearing damage: During the operation of the bearing, due to its own wear and tear, the temperature will rise, the amplitude will increase, and the work rate will be affected. Therefore, it is necessary to replace the bearing in time to improve the quality of the equipment.

5. Damage to the seal: The mechanical seal is composed of a frame, a spring and an alloy friction surface. It is water-cooled and cooled, and the temperature rises due to lack of water, or wear and aging, cooling water corrosion and other reasons cause damage. Mechanical seals are precision equipment accessories, and must be replaced by professionals, and installed in strict accordance with maintenance and installation specifications.

Chemical Pump Maintenance

1. Replacement and installation of shaft coupling elastic pad

The pump and fixed motor should be evenly distributed on the coaxiality to ensure that the shaft coupling is evenly stressed after the connection is started. By adjusting the pad iron, make the axis line of the two halves of the coupling consistent. To calibrate the other connected shaft, generally the height of the motor is corrected so that the two halves of the coupling are at the center of the horizontal plane. Use a feeler gauge to check whether the connection planes of the two halves of the coupling are evenly spaced, otherwise it should be readjusted. Evenly connect the two halves of the coupling. After the calibration is completed, tighten the connecting screws of the motor base evenly in sequence: 1. Motor 2. Electrical connection 3. Pump connection 4. Operating equipment

2. Replacement of mechanical seal

During the disassembly process, dismantle in strict accordance with the order from outside to inside, use special tools, and knocking is strictly prohibited. Remove the shaft cap, anti-retraction gasket, impeller, pump casing, seal cover, and remove the old seal in sequence. Before the new seal is installed, the sealing body and seat should be thoroughly cleaned, and an appropriate amount of lubricating oil should be added so that the seal can move freely in the sealing body according to the process coefficient and run smoothly. Then the pump parts are assembled in turn, and finally water is injected to test the tightness.

3. Bearing replacement

a. When assembling and disassembling, the force should act on the end of the removed ring, and at the same time, the force should be applied evenly on the entire circumference of the ring.

b. The assembly sequence of the inner and outer rings of the bearing can generally be determined according to the degree of tightness of the combination of the inner and outer rings of the bearing and the matching accessories. If the inner ring and the shaft are closely matched, the bearing should be installed on the shaft first; otherwise, the outer ring and the shaft should be installed first. If the fit of the bearing seat hole is tight, put the bearing into the bearing seat hole first; when the fit of the inner and outer rings is tight, they can be pressed in at the same time.

c. The joint surface should be coated with lubricating oil before pressing.

d. When installing the rolling bearing, the end face with the mark code on the bearing should be installed in the visible direction, so as to check when replacing.

e. When assembling rolling bearings, the pressure (or impact force) should be directly applied to the end face of the ring to be matched, and the pressure is not allowed to be transmitted through the rolling elements.

f. After the rolling bearing is mounted on the shaft or installed in the housing hole, no skewing is allowed.

g. Among the two rolling bearings on the same shaft, one of the bearings must have room for axial movement when heated and expanded.

h. Keep it clean during assembly to prevent foreign matter from entering the inside of the bearing.

i. The assembled bearing should rotate flexibly, have low noise, and the working temperature should not exceed 50°C.