Model selection must be based on the following processes.
I. Clear pressure.
The rated value pressure of the selected dosing metering pump model should be slightly higher than the specific maximum pressure necessary, generally higher than 10 to 20%. Do not have to pick too high, the pressure is too high consumption of electricity and energy, to enhance the input and operation of the facility costs.
Second, clear flow.
The selected metering pump flow rate should be equivalent to or slightly larger than the required flow rate of the processing process. Plunger metering pump selection flow of the use of the range in the metering pump rated value of the flow range of 30 to 100% good, when the metering pump repeatedly reproduce high accuracy. Give full consideration to cost-effective, proposed metering pump real must flow rate selection for metering pump rated value flow rate of 70 ~ 90%.
Third, clear pump impeller (hydraulic drive end) material.
Metering pump outlet pressure after the actual specifications model clear, and then based on the characteristics of the overflow medium to select a part of the material overflow, this step is particularly critical, if the choice is not reasonable, may lead to media leaching destroy overflow components or media leakage environment pollution system software, etc.. More serious when there may also lead to major safety accidents.
Other dimensions.
In the selection of metering pumps, but also give full consideration to the required metering pump accuracy level, the higher the accuracy level the greater the capital investment. Metering pump general ambient temperature in -30 ~ 100 ℃, unique metering pump whose operating temperature range is wider (such as continuous high-temperature liquid metering pump with thermal insulation cylinder clamps, its transport ambient temperature up to 500 ℃). For the particle size distribution of the medium, it is specified that it should be less than 0.1mm.
For more than 0. 1mm media, the purpose of the pump overflow structure can be changed to meet the requirements. For the viscosity of the medium, generally should be in 0 ~ 1000mm / s, unique metering pump up to 6000mm2 / s, mechanical equipment diaphragm type metering pump flow is measured at the calibrated rated value of the pressure of the larger flow (indoor temperature when transporting cold water), if the pressure is reduced, the derived flow will be higher than the calibrated.