Water cannot be filled into the lockbox flushing water tank.
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Our lockbox flushing water tank is now filled to 70% capacity, and the opening degree of the water supply valve needs to be much larger than before. Now I’ll explain the indicators: (FV1213 – valve for filling the wash water tank in the lock hopper; FV1321 – flow control valve for sending graywater to the wastewater treatment system). FV1213: 100%; FV1321: 14%, 180A. FV1213: 21%; FV1321: 14%, 170A. FV1213: 21%; FV1321: 0%, 145A. FV1213: 0%; FV1321: 0%, 133A. The current value corresponds to that of the low-pressure graywater pump. I hope everyone will consider this carefully (please check the valve positions both at the control room and on-site)
This post was last edited by xuqinger on 2010-3-17 08:51. The valve opening degree corresponds well to the current; pay attention to the alignment between the title and the content
Previously, driving at 20 would allow the level to reach 70% within the specified time, but now it only reaches 30%. When the water addition valve is adjusted from 20 to 100, the current increases by only 10A. In the case of wastewater treatment, when it is adjusted from 0 to 14, the current increases by 25A. So, since the water addition valve has 10 more settings than before, is this normal?
It is normal for the valve position to change after operation for some time, especially after instrument maintenance or adjustments to the valve. Let’s use the simplest method to rule this out: 1. Set FV1321 to 0% and FV1213 to 50%, and check whether the liquid level in the rinse water tank rises; if it doesn’t, a. Check the pipelines leading to the rinse water tank. If there is a problem with the pipeline, check the pressure gauge at the pump outlet on site. b. Inspect the FV1213 valve on-site. c. Try turning on the FV1213 bypass to see. 2. FV1321 at 0%, FV1213 at 50%. If the liquid level in the wash water tank is high, it is sufficient to increase the opening degree of the valve for FV1213 during operation.
For these valves, I checked the relationship between their position and the current; when the valve used for wastewater treatment was opened wider, the current increased significantly. This shows that there is nothing wrong with our pump. Our flow meter has been damaged (an electromagnetic flow meter); the flow rate indicated by it is getting lower and lower. Since that flow meter stopped working, the valve has been adjusted from position 20 to position 30. A few days ago, due to the type of coal used, the operating temperature was high, which resulted in an excessively long locking time for the hopper. Could it be the structure? Upon on-site inspection, it was indeed observed that the valve moved. I also checked his valve stem; the valve indeed moved.
Where is the dispersant addition port? Could scaling and blockage occur in the lockbox flushing water heat exchanger? It is possible to consider checking the heat exchanger tube side after parking ； It is possible that scaling has formed on the inner wall of the pipe, resulting in an increased pressure drop due to resistance and a reduced flow rate.
It’s possible that this is the reason mentioned by the moderator: our dispersant inlet is located at the pump’s inlet, and the valve has now been opened to 100%. Since the valve moves a large distance, the increase in current isn’t very significant. The outlet pressure of the pump is now 0. It’s 7 MPa now; after the heat exchange, it was below 0.55 MPa. I think it was 0.65 MPa before that. The bypass at the site has already been opened halfway, but there isn’t much change in the flow rate. Turning the front water valve on and off several times at the site had some effect. It can use 10 minutes less than before.
Greywater pipes tend to scale easily; just clean them after the system is shut down
The heat exchanger is clogged, resulting in a slightly lower head pressure of the low-pressure ash water pump.
If it is scaling and blockage in the lockbox flushing water heat exchanger, it seems that the design team did not consider this thoroughly, as there is no preheating bypass line in the ash water pipeline of this heat exchanger.