Diaphragm pumps are well suited for continuous operation
These very wear-free pumps are often used where they have to work for a long time without maintenance. They are also particularly suitable for conveying contaminated media.
Advantages of the diaphragm pump
How diaphragm pumps work
This type of pump is basically a piston pump in which the function of the piston is replaced by one or two diaphragms. If the diaphragm is pressed into the chamber containing the pumped material, it is displaced and thus conveyed out of the pump. If the diaphragm is deflected to the other side, it creates a vacuum through which the material is sucked in. The diaphragm is deflected electromagnetically, mechanically, pneumatically or hydraulically.
For the electromagnetic deflection of the membrane an oscillating armature is used, whose movement is generated by an electromagnetic alternating field. Pumps with this diaphragm deflection are also called oscillating armature pumps. They have a comparatively good efficiency.
The simplest pumps with mechanical diaphragm deflection are the hand diaphragm pumps. The diaphragm is moved by a crank handle. Larger pumps with mechanical deflection are usually driven by an electric motor via an eccentric and a connecting rod. With micromembrane pumps, the piezo actuators sit directly on the membrane. This design is mainly used for dosing small quantities of liquid.
The pneumatically driven pumps have two diaphragms connected to each other. Each of these membranes separates the liquid chamber from an air chamber. Air is alternately pressed into one of the air chambers. This creates an overpressure in one chamber and a vacuum in the other. The liquid is pressed out of the positive pressure chamber and sucked into the negative pressure chamber. This design requires a lot of energy, because compressed air has to be compressed constantly. It is often chosen for barrel pumps.
A hydraulic drive of the diaphragm is referred to as a piston diaphragm pump. Here the diaphragm is deflected by the piston movement.
Applications of these pumps