How to adjust the flow rate of a metering pump
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May I ask: 1. Why is a plunger pump chosen for metering pumps, and what are the advantages of plunger pumps? 2. How does a metering pump adjust its flow rate – through a handwheel or a variable-frequency motor?
The outlet pressure of a plunger pump is higher than that of a diaphragm metering pump. Metering pumps regulate flow by adjusting the stroke; in other words, it is adjusted using a handwheel
Reasons for using plunger pumps: 1: Positive-displacement pumps are convenient for measurement. 2: As long as the pump body of a plunger pump can withstand high stresses, it can handle any level of back pressure. 3: Simple structure.
The advantages and disadvantages of piston pumps are as follows: The piston is in direct contact with the process material; different materials require different piston materials. Suitable for high-temperature applications, up to 10,000°C. Suitable for applications with high inlet/outlet pressures. Good NPSH performance, allowing use with highly viscous materials. There is slight leakage
Using frequency conversion for adjustment is convenient, and it allows the system to receive signals for automatic adjustment, resulting in a high degree of automation……
Piston-type or diaphragm-type pumps can be used for metering purposes; piston-type metering pumps are widely utilized in the petrochemical industry due to their simple structure and resistance to high temperatures and pressures. The flow rate of a plunger metering pump is adjusted by rotating the adjustment handwheel, which in turn causes the adjustment screw to rotate; this changes the distance between the bow-shaped links, thereby altering the stroke of the plunger (piston) within the pump chamber and thus determining the flow rate. The scale on the adjustment handwheel determines the plunger stroke, with an accuracy of 95%.
Why is a plunger pump chosen for metering pumps? The selection is based on factors such as the medium being handled; the flow rate can be adjusted between 0.2 and 30,000 liters per hour, the pressure can be regulated up to 65 MPa, and the volumetric efficiency is over 98%, meaning the accuracy is within the range of 0.3 to 1%. How is the flow rate adjusted in metering pumps – through a handwheel or with an inverter-driven motor? Three adjustment modes: manual, automatic, and variable frequency. If the original poster does well, give them some extra points.
Good knowledge, I’ve learned it! !