Selection of variable-frequency drive motor for screw pumps
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Our company uses G20-1 single-screw pumps for handling highly alkaline setting agents. The required flow rate is between 2 L/MIN and 10 L/MIN. Electric control is used for regulation and metering, with the aim of maintaining a stable flow rate over an extended period of time. I have opted for a 6-stage variable-frequency motor, as low-frequency operation over long periods is necessary; however, the motor stops working due to overheating when operating at low frequencies. A digital flow meter is used for measurement, but the readings fluctuate greatly and are not reliable. I would appreciate any advice you can offer. Thank you
Metering pumps with a plunger structure can be used
In the case of motors that are not variable-frequency motors, it is difficult for heat to dissipate when the motor operates at low frequencies. Even with variable-frequency motors, excessive heating can occur if they operate under light load for extended periods. Based on what the poster has said, it is possible that the pumps you have chosen are too large.
If it operates at a low frequency for an extended period of time, your motor will not be able to handle it and will get damaged over time; it is recommended not to operate it at frequencies below 10Hz. Also, I’m not sure whether your variable-frequency motor comes with a fan built-in – if not, you can add one to help with cooling. Additionally, it is recommended that you consider using a metering pump, which allows control by adjusting the plunger stroke.
It is best to first confirm whether the motor is an inverter-driven motor. If it is not an inverter-driven motor and is used in an inverter setup, it is prone to overheating and developing problems. Many users try to solve this issue by increasing the motor’s power rating; however, it is better to use an inverter-driven motor, with a power rating that matches the actual requirements. Excessive load can lead to overheating, malfunctions, and even damage to the motor.
We use variable-frequency motors, but we have conducted experiments showing that Wannan motors can only handle frequencies above 20HZ; as a result, the flow rate regulation range for the screw pump is only 4-10 L/MIN, which is not sufficient. Have you ever used imported variable-frequency motors that can operate continuously at 10HZ?
We use variable-frequency motors, but we have conducted experiments showing that Wannan motors can only handle frequencies above 20HZ; as a result, the flow rate regulation range for the screw pump is only 4-10 L/MIN, which is not sufficient. Have you ever used imported variable-frequency motors that can operate continuously at 10HZ? Thank you
Can’t find a metering pump with a lower flow rate that suits your needs? If it’s still there, I would recommend switching to a pump with a lower flow rate; this way, a variable frequency drive with such a low load wouldn’t be necessary