The problem of pumps frequently adjusting flow rate
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Sea friends, I have a question I’d like to ask you all. I hope those with experience can give me some advice: 1. We have a low-pressure condensate pump, which is a standard centrifugal pump used to drain the water from the steam condensate tank. When the liquid level is high, the automatic control valve opens wider; when the level is low, it opens narrower. This automatic adjustment occurs frequently, and as a result, the bearings and mechanical seals of this pump often get damaged. I think this is related to the constant pressure buildup caused by such frequent adjustments. What do you all think? Are there any solutions? 2. Similarly, there is a wastewater pump that is a canned motor pump, used to drain the wastewater from the wastewater tank. The valve position is high when the liquid level is high, and it is low when the liquid level is low. This pump also often has faulty bearings, shaft sleeves, and thrust discs. Does anyone have any ideas?
The outlet valve of the centrifugal water pump can be used to adjust the pump’s flow rate; at this time, it is necessary to ensure that the motor’s operating current does not exceed the rated value. The flow rate of the water pump can be reduced by lowering the motor speed. By using an inverter to change the frequency and thus adjust the speed, it is possible to regulate flow rate while saving electricity. If a permanent reduction in flow rate is required, this can also be achieved by cutting the outer diameter of the centrifugal pump impeller. For reference!
The design institute advises that you can control the frequency of the inverter via the liquid level, and by controlling the frequency, you can adjust the motor speed, thereby reducing or increasing the flow rate. Many condensate pumps are variable-frequency.
Can automatic control be disabled and replaced with manual intermittent operation?
A bypass pipeline is provided at the outlet, and a control valve is installed on this bypass pipeline; the flow rate is adjusted by controlling the degree to which the valve is opened. However, this method results in high energy losses, so it is not recommended. As for reducing the diameter of the impeller as mentioned earlier, pumps purchased generally come with several impellers of similar diameters to ensure wide applicability
1. Will the pump stop automatically when it reaches a certain low level? If the pump continues to run with the outlet closed, this will lead to an increase in the temperature of the medium, causing cavitation and thus damaging the pump； If it shuts down automatically, could the temperature of the condensate water be too high, leading to frequent cavitation in the pump? 2. If the shielded pump does not shut down automatically, the increase in the temperature of the medium can affect the internal clearance levels, leading to increased wear. Blockages at the inlet can result in a reduced flow rate and vacuum conditions within the pump, all of which can cause rapid wear of the bearings.
1. The centrifugal pump should be able to operate under pressure buildup conditions. After all, when holding back voltage, it is possible to see whether the operating current increases smoothly as well. It is recommended to check whether it is caused by poor sealing fluid. 2. Shielded pumps are also of the centrifugal pump type; moreover, they are particularly sensitive to particles, especially in wastewater environments, so it is best to eliminate issues related to the medium itself.
Oh, the cost is a bit high; it’s necessary to replace the motor with an inverter-driven one and add an inverter as well.:
It’s quite troublesome, right? Setting up a level alarm means having to turn it off many times a day. There are already not enough people on site, so it might be impossible to handle all of this