Metering pump as wellAccording toFixed displacement pump or proportional pumpYesOne type can meet the requirements of various strict process flows, and the flow rate can be within0-100%A special positive displacement pump with stepless adjustment within a range, used for conveying liquids (especially corrosive liquids)It is a commonly used accessory in water treatment equipment.Now let's talk about the selection of metering pumps7Here are some precautions.

I."RunPressure

"SelectiontheMetering pumpRated pressuretoSlightly largerAt the actual required pressureScope10～20%. Excessive pressure will waste energy and increase the investment and operating costs of equipmentThereforeDon't choose too high.

Ii."Run"Traffic"

The selected metering pumpthe"Traffic"Also≥Required flow rate. The application scope of the metering pump flow is within the metering pumpRated flow"Range30～100%At this time, the repeatability and reproducibility accuracy of the metering pump is high.From the perspective of operating costsThe actual required flow rate of the metering pump is selected as the rated flow rate of the metering pump70～90%.

Iii.Material of the pump head (hydraulic end)

For"Does not occurIt will cause corrosion and damage to the flow-through components of the medium or medium leakage and pollution,After the specific model and specification of the metering pump are determined, the material of the flow-through part should be selected based on the properties of the flow-through medium. Generally speaking,The material of the metering pump head is:RPP,PVC,PTFE,SS304andSS316Wait.RPPIt is easy to form, has a low cost, and is resistant to acids, alkalis and high temperatures. However, it is not suitable for organic solvents, strong acids, alkalis and liquids containing hypochlorite ions, and the concentration is limited.PVCEasy to form, low cost, resistant to acid and alkali corrosion, strong acid and alkali and above40℃The measurement of liquids is not suitable for the drinking water industry.PTFEHigh cost, difficult to form, suitable for various media, heat-resistant, and stable and reliable material quality.SS304/SS316It is not resistant to acids and alkalis, but suitable for high-temperature liquids and organic solvents.

FourDiaphragm of the metering pump

Metering pumpCommonly usedPTFEMaterial diaphragmPTFE+Reinforced rubber composite diaphragms, some of which are embedded with steel wire mesh and the like inside the rubber diaphragm to increase its strength, have a low cost and large elastic deformation, which greatly reduces the production cost. However, after long-term operation, the heat from the pump body will be transferred to the rubber surface, which can easily lead to the aging and damage of the diaphragm.

V. Working Temperature

The general working temperature of the metering pump is－30～100℃Special metering pumpsOperating temperature rangeWider (such as high-temperature liquid metering pumps with insulation jackets, their conveying temperatures can reach.500℃"

Vi. Medium Viscosity

For the viscosity of the medium, it should generally be within0～1000mm/sSpecial metering pumps are available6000 mm2/s, The flow rate of the mechanical diaphragm metering pump is measured under the calibrated rated pressure (when transporting clean water at room temperature). If the pressure drops, the output flow rate will be higher than the calibrated one.

Vii. Medium Particle Size

The particle size of the medium should be less than0.1mmFor greater than0.1mmFor the medium, the flow structure of the pump can be modified specifically to meet the requirements.

The above isSelection of metering pumps7Please note that if you encounter any problems in the selection of metering pumps, please consult Beijing Yuanlai Water Treatment Equipment Co., LTD., which specializes in water treatmentYou can trust it!