Diaphragm pump working principle

       Diaphragm PumpIt is a rather unique form of a volumetric pump. It operates by the back-and-forth movement of a diaphragm to alter the chamber volume, thereby吸入 and 排出 liquids.

The diaphragm pump is primarily composed of two major parts: the transmission section and the diaphragm cylinder head. The transmission section is the driving mechanism that drives the diaphragm plate to move back and forth, with transmission methods including mechanical, hydraulic, and pneumatic transmission, among which hydraulic transmission is more widely used. The working section of the diaphragm pump is mainly composed of the crank and connecting rod mechanism, plunger, cylinder, diaphragm, pump body, suction valve, and discharge valve, among which the driving mechanism consisting of the crankshaft, connecting rod, and cylinder is very similar to that of a reciprocating plunger pump.

Diaphragm pumps operate by a crank and connecting rod mechanism, which is driven by an electric motor. This mechanism drives the plunger to reciprocate. The plunger's motion is transmitted through the working fluid (usually oil) within the cylinder to the diaphragm, causing it to pump back and forth.

The缸head of the diaphragm pump is mainly composed of a diaphragm separating the fluid to be conveyed from the working fluid. As the diaphragm moves towards the drive mechanism side, the pump cylinder is under vacuum and draws in the fluid. When the diaphragm moves to the other side, the fluid is expelled. The fluid to be conveyed is separated within the pump cylinder by the diaphragm and working fluid, contacting only the pump cylinder, suction valve, discharge valve, and the internal side of the diaphragm, not the plunger or sealing devices. This ensures that critical components like the plunger operate entirely in an oil medium, maintaining optimal working conditions.

Diaphragm sheets must possess excellent flexibility and good corrosion resistance, typically made from materials such as rubber. The pot-shaped components with perforated sides on both sides of the diaphragm sheet are designed to prevent localized excessive deformation of the membrane, commonly referred to as a diaphragm limiter. Pneumatic diaphragm pumps have good sealing performance, allowing for relatively easy achievement of leak-free operation, and are suitable for conveying corrosive liquids like acids, alkalis, salts, as well as high-viscosity liquids.