Can the large-flow circulating water pump be set to self-start?
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The circulating water pump has a flow rate of 13,400 cubic meters/h and a check valve at the outlet. Normally, four pumps run at the same time. Because two electric pumps suddenly stopped when section A was powered down, and the power supply returned to normal within 3-5 seconds, is it possible to set the two electric pumps to start automatically to ensure that the pressure and flow of the entire circulating water main pipe meet the production equipment? After calculation, the starting current of the two electric pumps will not affect the power grid.
Yes, please arrange for a professional automatic control engineering designer to implement it. . . :lol
If the power shaking time reaches 5 seconds, it is relatively long. Under normal circumstances, restarting can be achieved on the electric control cabinet. This needs to be adjusted by electrical personnel. Realized through electrical restart cabinet or time relay
Are the inlet and outlet valves of the pump also normally open? It doesn't seem good.
It can indeed be realized by electrical personnel through the electric control cabinet. There is a hydraulically controlled check valve at the pump outlet. The opening and closing of the check valve is interlocked with the motor. After the motor is turned on, the check valve automatically opens fully within 30-60 seconds.； The motor stops running and the check valve closes completely within 2.5-20 seconds. The pump inlet and outlet valves are open.
What to do if the pressure cannot be pumped up? It is best to set up a buffer tank (liquid level monitoring) at the outlet, a vacuum pump to evacuate (pressure monitoring), and a large-diameter quick-opening remote valve at the outlet of the circulating water pump. In order to avoid valve failure, you have to set up an auxiliary line, etc. It is too troublesome. It is better to do it manually. After all, the chance of power failure is relatively small, and the equipment investment cost is too high:)
It is controlled by an electric contact pressure gauge, which is quite simple.
Yes, yes, just install the automatic control system. However, we must consider how to ensure that the pump is evacuated. Once evacuated, the damage to the pump will be greater. The outlet valve will be in a normally open state, which does not comply with the pump opening procedure. Our company's pipelines are also equipped with check valves, but the pumps must be emptied every time they are turned on. They often cannot be opened immediately due to low liquid levels, and the liquid level must reach the required level.
It is recommended not to set it up like this, because no one is in front of you to start it. What to do if someone is nearby or what to do if the pump is stuck. It is likely to burn the motor. It is recommended that high-power pumps not be set to start by themselves. Moreover, power outages are not a common occurrence.
Choose an appropriately larger motor model and let the electrical design: ⒈A delayed start protection ； ⒉Two backup pumps can start automatically ； ⒊The four pumps are self-starting and standby for each other. It can fully meet the needs of the landlord.
Now the motor has been determined to be 2550 kW and installed. The probability of power outage is indeed very small, but due to the influence of circulating water, all production units of the entire ethylene plant were shut down, which felt like a huge loss. Like this 800 million/h circulating water volume, the stable water level in the suction pool ensures that the centrifugal pump will not cause cavitation. Now we are afraid of harm to the motor.
Self-starting is theoretically possible, but it is also necessary from operational considerations. In fact, some equipment that is critical to the operation of the plant are also set up with self-start, such as the boiler feed water pump and the 6kv 1000KW motor. But we must first consider the safety of self-starting. For example, the owner's circulating water pump has a flow rate of more than 10,000 and a power of more than 2,000KW. The load impact on the power supply circuit during self-starting is very large, and the performance requirements for the power distribution cabinet are also very high. Even if self-start is set, the integrity of the distribution cabinet and the feedback response of the control loop must be checked frequently to avoid unprepared situations.
Our circulating water pump is 18805 cubic meters with a power of 1300kw. I am not sure about its internal structure and specific working principle. Please give me some advice!
Before turning on the pump, you should first turn on the power and then evacuate it. There are prescribed procedures!