Diaphragm pump is a special form of positive displacement pump. It relies on a diaphragm plate moving back and forth to change the volume of the chamber to inhale and expel fluid.
Pneumatic diaphragm pump is mainly composed of transmission part and diaphragm cylinder head two major parts. The transmission part is the driving mechanism that drives the diaphragm piece to and fro. Its transmission forms are mechanical transmission, hydraulic transmission and pneumatic transmission, etc., among which hydraulic transmission is widely used. The working part of diaphragm pump is mainly composed of crank connecting rod mechanism, plunger, liquid cylinder, diaphragm, pump body, suction valve and discharge valve, which is composed of crank connecting rod, plunger and liquid cylinder driving mechanism and reciprocating piston pump is very similar.
Diaphragm pump work, crank connecting rod mechanism under the drive of the motor, driving the plunger for reciprocating movement, the movement of the plunger through the liquid cylinder working liquid (generally oil) and spread to the diaphragm, so that the diaphragm agitation.
Pneumatic diaphragm pump cylinder head is mainly composed of a diaphragm piece will be transported liquid and working liquid separate, when the diaphragm piece to the transmission mechanism side movement, pump cylinder work for negative pressure and suction liquid, when the diaphragm piece to the other side of the movement, the discharge of liquid. The liquid is transported in the pump cylinder is separated by the diaphragm and the working liquid, only with the pump cylinder, suction valve, discharge valve and diaphragm side contact, and do not contact the plunger and sealing device, which makes the plunger and other important parts completely work in the oil medium, in a good working condition.
Diaphragm sheet to have good flexibility, but also have good corrosion resistance, usually made of ptfe, rubber and other materials. The pan - like parts with mesh holes on both sides of the diaphragm are set up to prevent excessive local deformation of the diaphragm, generally called diaphragm limiter. Pneumatic diaphragm pump sealing performance is good, can be more easily to achieve no leakage operation, can be used to transport acid, alkali, salt and other corrosive liquids and high viscosity liquid. In the pump two symmetrical working chamber each is provided with a diaphragm, by the central link rod will be connected to form a whole. The compressed air enters the distribution valve from the inlet of the pump, and the compressed air is introduced into one chamber through the distribution mechanism, which pushes the diaphragm to move in the chamber, and the gas is discharged from the other chamber. Once the end of the stroke is reached, the valve mechanism automatically directs compressed air into the other working chamber, pushing the diaphragm in the opposite direction so that the two diaphragm reciprocate continuously and synchronously. In the figure, the compressed air enters the valve and the diaphragm moves to the right. Then the suction force of the chamber makes the medium flow into the chamber by the inlet, and the ball valve is pushed into the chamber. The ball valve is locked by inhalation. The medium in the room is squeezed, push the ball valve out of the outlet, at the same time make the ball valve locked, anti-flow, so that the circulation of media constantly from the entrance of inhalation, outlet discharge.