Metering accuracy of metering pump
The metering accuracy of metering pumps refers to the accuracy of flow reproducibility, which is usually calculated according to the maximum flow rate. Within the range of 10-100%, the metering accuracy of the general metering pump is (+) 1% (the special metering pump has higher precision). The main factors affecting the metering accuracy are the sealing of the plunger packing and the perfection of the suction and discharge valves.
Piston metering pump has the advantages of high metering accuracy, wide adjustment range and high pressure, but there is leakage in the packing seal, which will affect the metering accuracy of the pump after the packing is corroded and worn. The flow rate of this metering pump is generally 4~4000 litres / hour, and the pressure is generally below 5 x 105 pa.
The main advantage of diaphragm metering pump is that it has no leakage, so it is especially suitable for situations where leakage is not allowed, such as the transport of flammable, explosive, toxic and radioactive media, but also can be used to transport liquid containing solid particles, so its development is very fast. The flow rate of this metering pump is generally less than 2500 litres / hour, and the pressure can reach 35 MPa.
The use of metering pump can complete three functions of conveying, measuring and adjusting, thus simplifying the production process, realizing automation and semi-automation, and improving product quality. Using multi-cylinder or multi-metering pump, several kinds of media can be mixed in the reactor according to the exact proportion.
Metering pumps are increasingly used in chemical, refining, pharmaceutical, food and nuclear industries. Metering pump efficiency is low, generally 20%, and power is very small.
Metering pump is also called quantitative pump or proportional pump. Metering pump is a kind of special volume pump which can meet the needs of various strict technological processes. The flow rate can be steplessly adjusted in the range of 0-100%, and is used to transport liquids (especially corrosive liquids). Generally, it can be divided into two categories: plunger metering pump and diaphragm metering pump.