Single-stage single-suction centrifugal pump bearing lubrication resolve
IS series single stage single suction centrifugal pump, due to design reasons, centrifugal pumps used rolling bearing with oil lubrication, dynamic seal leakage is very serious threat to the security and stable operation of the equipment, work in a few years, several times on the bearing housing seals The piecemeal reform have achieved certain results. But the leak problem is not completely resolved, after a practice change oil lubrication grease lubrication, to good effect.
Centrifugal lubrication of rolling bearings are mainly reduced friction power, lower wear rates, but also for cooling, dust, rust and vibration effects. Improve equipment lubrication is to ensure normal operation of equipment. Reduce equipment wear and tear, accident prevention equipment, reduce power consumption and extend the effective measures to repair cycle and service life.
I plant centrifugal roaster circulating water system used for single-stage single-suction pump, various technical parameters are as follows:
Model IS150-125-250, flow 200m3 / h, head 20m, shaft power 18.5kw, speed 1450r / min.
Such type of pump lubrication of rolling bearings is composed of 30 # (winter) or 40 # (summer) lubricating machinery. Due to the design of dynamic seal leakage is very serious reasons, not only cause a lot of waste oil, bearing burn, and pollution of the environment is not conducive to safe operation of equipment and civilized production. After several years of work, in order to solve this problem, many times piecemeal reform.
1, the course of the transformation of lubrication
1.1 felt seals to single Simmerrings
Original bearing housing seals are sealed with felt. Leakage is very serious about each pump fuel 300kg / a, cause a lot of waste oil, a thick layer of oil on the ground.
To change this oil spill situation, change the felt seal skeleton seal, as follows:
① inside and outside of the bearing housing cover processing, car out of a Φ65mm, 12mm deep the hole, put a suitable specifications for 45mm × 60mm × 12mm of oil seal.
② removing the blankets, the oil seal lightly with a hammer to break into, and correctly installed.
After the transformation, the device is working properly, vibration displacement of about 0.04mm, outer measure bearing temperature is about 50 ℃, only about 50kg each pump consumption of oil. Maintaining the pump house clean, eliminate the cause occurs due to lack of oil bearing, shaft damage accidents, the equipment is running well.
1.2 single to double oil seal oil seal
In order to make more leakage reduction, according to the structure of the bearing box cover, also proposed transformation plan, the bearing housing cover bore machining is Φ65mm through holes. The single to double oil seal oil seal:
Test run showed that this method to prevent oil leakage in the short term is very effective. But continuous operation six months later, due to the oil seal wear will increase the amount of leakage.
2, seal defects
The felt seal to seal, the use of 4a, although better, but there are obvious flaws.
In practice, because the skeleton seal life is short, need frequent replacement, the replacement seal, all the equipment necessary to disintegration, on the one hand to increase labor intensity, on the other hand in the process of disintegration of maintenance equipment, sometimes causing the impeller, damage bearings and other parts, the device does not meet the requirements of economic management, but if you do not change the oil seal, causing leakage, is not conducive to sealing, but also directly affect the bearing life. In short, it proved: seal does not completely solve the leakage problem with this bearing box structure.
3, instead of lubricating grease
Currently, nor cheap seal leaks yet, some good sealing effect, but the price is expensive, it is not economically viable. After investigation, it decided to boldly experiment - instead of lubricating grease to lubricate.
3.1 Transformation method
Considering the shaft power is only 18.5kw, flow only 200m3 / h; pump speed is 1450r / min, the line speed of 3.4m / s from the above two points of view, with grease lubrication is feasible.
3.2 Specific methods are as follows
① the oil tank let go of the bearing housing for cleaning.
② to cover the ends of the bearing housing and open drain hole plugs to eliminate air cabinets.
③ with butter lithium grease gun to fill the fuel tank to the bearing hole, added to the grease from both ends of the cover and put the hole extrusion, regarded as fill, and tighten the bearing cap and drain hole plugs . Hand drive cars, the grease in the housing distribution.
After starting the pump, open the outlet valve, the pump is running under normal circumstances, to monitor the pump bearings at both ends and oil temperature conditions. With an infrared thermometer to monitor the temperature, the data shown in Table 1:
Table 1 bearing temperature change with running time running time / h inside bearing temperature / ℃ outboard bearing temperature / ℃ temperature / ℃
0.17 404,135
0.33 424,435
0.50 444,735
0.67 475,035
0.83 495,335
1505435
2505435
10505334
240455032
720444931
After transformation vibration displacement of about 0.04mm.
Grease quality is good, no change, water pumps working properly, you can see the temperature and vibration monitoring data from monitoring data, instead of the lubricating grease is feasible and can be extended using the same type of pump.
3.3 Grease lubrication
Grease leakage is not easy, is conducive to water pump bearing lubrication to ensure safe and stable operation of the pump, greatly reducing the amount of fuel and refueling. Not only fuel, but also reduce labor intensity. Specifically:
① save oil costs. Use grease each pump consumption 9kg / a, at a cost of 63 yuan / a. Whereas oil consumption in the oil seal in good condition 4kg / month, at a cost of 200 yuan / a. Each pump can save 137 yuan / a, greatly reduced cost lubrication.
② reduce maintenance costs. Simmerrings average life expectancy of four months, to replace the seal, disintegration of maintenance required each year about three times, to lithium grease lubrication, reducing labor costs. Material costs, machinery costs, and in the repair process to avoid causing damage to the equipment parts.
③ extended equipment operating cycle. From vibration. Temperature and other aspects of monitoring, using grease sealing performance, bearing a well-functioning, extending bearing life.
④ improve the job environment.
4. Conclusion
In short, instead of mechanical lubricating grease, for this low speed, pump flow is not practical, and there is a clear economic and environmental benefits, is to make the devices economical to run an effective measure.
