Trouble-cause troubleshooting method 1. After the pump is started, the outlet pressure will not rise. (1) The impeller rotation direction does not match.
(2) The pump is not sufficiently cooled, and there is gas in the pump.
exclude:
(1) Two-phase wiring of the motor input line is reversed (2) Continue cooling, and open the anti-gas valve or adjust the sealing gas pressure.
2. The pump's head or flow is insufficient.
(1) The motor speed is insufficient.
(2) Impeller or pipe fouling.
(3) Excessive gas enters the pump due to excessive seal air pressure.
exclude:
(1) Increase the speed.
(2) Cleaning.
(3) Adjust the sealing gas pressure.
3, the liquid can not be sucked, indicating that the pressure is vigorously beaten (1) the pipeline valve is not open or the pipeline resistance is large.
(2) Pipeline leakage.
exclude:
(1) Open or clean.
(2) Repair 4. The motor temperature rises.
(1) Motor problems.
(2) The impeller ring has been wiped.
(3) The labyrinth seal has been rubbed.
exclude:
(1) Electrician repair.
(2) Adjust the gap.
(3) Adjust the gap.
5. Sudden stop (1) The sealing gas pressure is low.
(2) The bearing is stuck.
exclude:
(1) Adjust the pressure.
(2) Cleaning or replacement.
6. Vibration or noise occurs (1) The fuselage is not the same as the rotor.
(2) Cavitation is caused by low inlet pressure of the pump or other reasons.
(3) Friction between the moving part and the fixing part (4) The rotor part is loose.
exclude:
(1) Adjustment (2) Adjust the pressure and deflate.
(3) Correction (4) Analysis of several liquid pump accidents for maintenance (1) Reform and commissioning of initial argon adjustment, when the argon pump is opened, the outlet pressure can not go up, use sufficient pre-cooling, the highest frequency control, filter inspection, through the wall The methods of heat insulation inspection and treatment of the inlet and outlet pipes have not been effective, and the on-site commissioning personnel of the manufacturers are also at a loss. When the East argon pump was changed, the pressure quickly went up and the operation was normal. After repairing the tower, it was found that the design of the inlet pipe of the No. argon pump was unreasonable, and there were too many elbows. The crude argon II tower was originally low, so that the NPSH inlet NPSH could not reach the design value and the outlet pressure could not go up. Renovate the inlet pipe and reduce the elbow. Start again and everything works.
(2) Because the top of the outlet tube of the argon pump is cracked, after stopping the maintenance, it is restarted. It is found that the argon pump runs shortly, the pressure drops, and after warming backflushing, it is restarted. This is still the case. Net, re-liquid, argon pump still can not operate normally. Finally, the argon pump is small and cold-cooled, and the imported filter network is removed. The problem is solved. According to the analysis, the reason for entering the pearl sand in the II tower is that the top of the argon pump outlet pipe is cracked. After parking, it leaks into the pearl sand and then flows to the top of the crude argon I tower. When heating, it flows into the crude argon II tower through the distillate gas pipeline. .
(3) The argon pump sealing gas began to use pressure nitrogen. It was soon found that the sealing system mixed gas discharge pipe had liquid discharge. The analysis concluded that the sealing gas was clogged. The pressure nitrogen was analyzed by a trace water analyzer, and the water content was found to be nearly 1000 ppm. The water was due to the piston. The nitrogen pressure machine cooling water steel sleeve is not leaking tightly, and the cause of the problem can be found. After the sealing gas is changed to the instrument air, the argon pump operates normally.
(4) For the first modification, the process of eliminating the refined argon column was adopted. The purity of trace nitrogen in semen argon has been unsatisfactory. It is suspected that it is caused by leakage of sealing gas. The study decided to change the sealing gas to argon pump outlet pressure argon. As a result, semen argon is still unqualified. The sealing gas is changed back to the instrument gas. Finally, the second phase of the transformation, after the addition of the refined argon column, the semen qualified.
(5) At the beginning of August this year, the running East Argon pump found a leaky night and switched to the West Argon pump. When starting, the speed can only be adjusted to 2900 rpm, the pump outlet pressure is about 0.58Mpa, and the liquid can't hit the crude argon I. The top of the tower. After consulting the manufacturer, the electrician re-commissioned the inverter, the speed reached 3600 rpm, the pump outlet pressure rose to 0.8Mpa, and the liquid could smoothly enter the top of the I tower.
The impact of the liquid pump sudden stop on the air separation system The liquid oxygen pump of the liquid oxygen adsorber has little effect on the air separation system. The main concern is the safety. The main cold liquid oxygen dangerous impurities should be analyzed and the liquid oxygen should be strengthened. Measures such as emissions. Some liquid pump sudden stops have a great influence on the air separation system. (1) The circulating crude liquid argon pump suddenly stops in the hydrogen-free argon-free process, the crude argon condenser is still working, and the large volume of liquefied liquid is smashed at the bottom of the crude argon II tower. Can not return to the crude argon I tower to participate in rectification, and then return to the upper tower, which will increase the oxygen content at the top of the crude argon I tower rapidly, the main cold liquid oxygen level is greatly reduced, and the main cold liquid oxygen level is too low. It is not conducive to safety; the second is that the heat exchange area is reduced, the air is not near, the oxygen production is reduced, and the main working conditions fluctuate greatly. (2) The circulating liquid oxygen pump in the process of separating the upper and lower towers is suddenly stopped, and the liquid oxygen is accumulated in the bottom of the upper tower, and cannot return to the main cooling, and the oxygen liquid level of the main cold liquid is also greatly reduced. The result is the same as above, and may also occur. Nitrogen plug. Therefore, for these two processes, if the pump suddenly stops, it must be recovered quickly; the normal pump should be carefully operated to ensure stable flow without interruption (the sudden increase of argon in the hydrogen-free argon process will contaminate the main cold liquid oxygen, Oxygen purity drops, even nitrogen plugs.). (3) For the internal compression process, the liquid pump suddenly stops, which will affect the supply of oxygen, nitrogen and argon. Here are some experiences on the operation of the liquid argon pump pumping:
Firstly, a reasonable circulating argon pump process is very important for the safe operation of the pump and smooth pumping. The process shown in Figure 4 is reasonable. Each argon pump has an independent inlet pipe to ensure that it does not affect the operation when pre-cooling or switching the standby pump. Pump; filter, compensator, check valve, safety valve are set as mentioned above; in addition, the argon pump outlet return pipe should not be too thin, otherwise the pump pressure is too high during full reflow, which is not conducive to the safety of the pump; It should be installed after the pump to ensure that the impurities on the filter can be blown off when heating. At present, the more advanced process is that two liquid pumps are used one by one, and the standby pump is in cold state and low speed operation. When the main pump fails, the standby pump can be put into normal operation immediately, so that the operation of the whole device is not affected.
The correct pumping operation is: pre-cooling and starting the standby pump, as described in the fifth item "Starting of the centrifugal liquid pump". It should be noted that a certain amount of argon containing about 98% of argon is consumed because of pre-cooling. The top regulating valve of the crude argon I column will be automatically shut down, the reflux ratio of the crude argon I column is lowered, the purity of the crude argon is deteriorated, and the trace oxygen is increased. Therefore, the crude argon production should be correspondingly reduced during the pre-cooling to keep the purity stable. In addition, after the standby pump is started, stop the pump immediately, pay attention to ensure that the flow rate of the crude argon I tower is stable, and do not fluctuate greatly, otherwise it will affect the working condition of the main tower.