Metering pumps are a special capacity pump that can meet a variety of stringent process requirements and can be steplessly regulated in the range of 0-100% for the delivery of liquids (especially corrosive liquids). Metering pumps, also known as quantitative pumps or proportional pumps, metering pumps are reciprocating volumetric pumps for accurate metering, usually require metering pump stability accuracy of not more than ± 1%. Metering Pump With the modernization of the industry towards the automatic operation, long-distance automatic control of the continuous development of this situation, metering pump supporting strong, to adapt to the media (liquid) a wide range of advantages is particularly prominent.
Metering pump classification
⒈ According to the overcurrent part: ⑴ plunger, piston type ⑵ mechanical diaphragm type ⑶ hydraulic diaphragm type
⒉ according to the drive: ⑴ motor drive ⑵ electromagnetic drive
3, according to the pump features: ⑴ large base ⑵ large base ⑶ in the base ⑷ small machine seat ⑸ microcomputer
Metering pump construction
Metering pump by the motor, gear box, cylinder and other three parts. The transmission box component is composed of a turbine worm mechanism, a stroke adjustment mechanism and a crank link mechanism; Metering Pump a high adjustment stroke is carried out by rotating the adjustment hand wheel to change the eccentricity of the moving shaft to achieve the purpose of changing the stroke of the plunger (piston). Metering Pump The cylinder block is composed of a pump head, a suction valve group, a discharge valve group, a plunger and a packing seal.
Metering pump working principle
The motor drives the worm by the coupling and decelerates the spindle and the eccentric wheel by the worm gear deceleration, which is driven by the eccentric wheel to push the bow of the bow. When the plunger is moved backwards, the suction valve is closed and the discharge valve opens, Metering Pump and the liquid is in the plunger to further Movement when discharged. The reciprocating work of the pump also works to form a continuous pressure, quantitative discharge of the liquid.
Metering pump installation
1. Exports higher than imports, to avoid siphon phenomenon
2. Pump head and injection valve require vertical installation
3. The attached tube can be tightened by hand, do not use the tool; Metering Pump thread does not use raw material belt
4. The supply voltage is stable and grounded
5. The installation environment is clean and spacious, well ventilated
Metering pump selection
First, to determine the pressure: the selected metering pump rated pressure slightly higher than the actual maximum pressure required, generally higher than 10 to 20%. Do not choose too high, Metering Pump too much pressure will waste energy, increase equipment investment and operating costs.
Second, to determine the flow: the selected metering pump flow should be equal to or slightly greater than the required flow of the process. The use of metering pump flow in the metering pump rated flow range of 30 to 100% better, then the metering pump repeat the high precision reproduction. Taking into account the economic and practical, Metering Pump it is recommended to measure the actual flow of the pump to choose the metering pump rated flow of 70 ~ 90%.
Third, to determine the pump head (hydraulic end) Material: metering pump specific model specifications, and then according to the properties of over-current media selection over-current part of the material, Metering Pump this step is very important, if improper selection, will cause damage to the media corrosion Over-current components or media leakage pollution systems. Serious may also cause a major accident.
Other aspects: in the choice of metering pumps, but also need to consider the required metering pump accuracy level, the higher the level of precision the greater the input. Metering pump general operating temperature of -30 ~ 100 ℃, special metering pump its operating temperature range is wider (such as with a high temperature temperature jacket jacket, the delivery temperature of up to 500 ℃). For media size, Metering Pump the requirements should be less than 0.1mm, for more than 0.1mm medium, the pump can be targeted to change the structure to meet the needs. For medium viscosity, generally should be 0 ~ 1000mm / s, special metering pumps up to 6000 mm2 / s, mechanical diaphragm metering pump flow is measured under the rated pressure measured under the maximum flow (water at room temperature ), If the pressure drops, the output flow will be higher than the calibration.
