Metering pump variety characteristics:

According to the structural characteristics of the hydraulic transmission end of the metering pump, the metering pump is often divided into four types: plunger type, hydraulic press diaphragm type, mechanical equipment diaphragm type and metal bellows type.

① Plunger metering pump. With the structure of the general reciprocating pump is basically the same, its hydraulic end by the hydraulic cylinder, plunger, suction and exclusion valve, sealing filler, etc., in addition to the general reciprocating pump hydraulic end design scheme, but also to solve the pump measurement precision has an impact on the suction valve, discharge valve, sealing and other components to carry out careful planning and selection.

② hydraulic press diaphragm metering pump. Generally called diaphragm metering pump. The single diaphragm metering pump is equipped with a layer of diaphragm in front of the plunger (the plunger does not touch the diaphragm), and the hydraulic end is divided into a drip chamber and a hydraulic press chamber. The drop chamber is connected to the pump suction and discharge valve, the hydraulic press chamber is filled with gear oil (light oil), and the hydraulic oil filter on the pump shell (fill the car fuel tank) is intercommunicated. When the plunger moves around, the load is sent to the diaphragm according to the gear oil and the capacity is changed by the tensile strain deformation before and after, which has the effect of transporting liquid medicine and achieving the requirements of accurate measurement.

③ Mechanical equipment diaphragm metering pump. The diaphragm is connected with the plunger tissue without gear oil system software, and the left and right movement of the plunger immediately pushes the diaphragm to the left and right tensile strain deformation.

④ Metal bellows type metering pump. The structure is similar to the diaphragm metering pump of mechanical equipment, only the diaphragm is replaced by a metal hose, and the plunger is fixed with a metal bellows. When the plunger moves repeatedly, the stainless steel bellows are pulled and reduced, and then the capacity of the cylinder is changed to achieve the purpose of drip and measurement

Metering pump total flow regulation method:

The common total flow regulation method of the metering pump has three ways: adjusting the plunger (or piston rod) stroke, adjusting the plunger reciprocating frequency or both of the above two methods, in which the method of adjusting the stroke is widely used. The method is simple and reliable, and can maintain high precision in small total flow rate. There are three methods of stroke adjustment

① Parking manual adjustment. Manually adjust the stroke of the metering pump during shutdown.

② Manual adjustment during operation. The radial offset is changed during the pump operation to indirectly change the gear half warp to adjust the stroke length. Common methods include N-shaped engine crankshaft adjustment, L-shaped engine crankshaft adjustment and axial force camshaft adjustment.

③ Automatic adjustment in operation. There are two common pneumatic regulation and electric control. Pneumatic control is to automatically adjust the stroke according to the change of the gas supply working pressure data signal. Electrodynamic control is the goal of automatically adjusting the stroke according to the transformation of the electronic signal.