The working principles and selection of piston air pumps and diaphragm air pumps

The working principles and selection of piston air pumps and diaphragm air pumps

First, working principle

Piston air pump

Core mechanism: Gas compression and transportation are achieved through the reciprocating motion of the piston within the cylinder. When the piston moves upward, the volume of the cylinder increases, and the external gas enters the cylinder through the intake valve. When the piston moves downward, the volume of the cylinder decreases, the gas is compressed and discharged through the exhaust valve.

Structural composition: It is mainly composed of components such as cylinders, pistons, intake valves, and exhaust valves. The piston fits closely with the cylinder wall and is connected to the driving mechanism (such as an electric motor or engine) through a connecting rod.

Features: Simple structure, suitable for high-voltage and low-flow scenarios, but with relatively low efficiency and high noise.

Diaphragm air pump

Core mechanism: The reciprocating deformation of the diaphragm is utilized to change the volume of the working chamber, thereby achieving the intake and discharge of gas. Pneumatic diaphragm pumps drive the diaphragm to move by compressed air, while electric diaphragm pumps drive the diaphragm by the motor driving the plunger.

Structural composition: It includes the pump body, diaphragm, check valve, drive mechanism, etc. The diaphragm completely isolates the working chamber from the driving part to prevent medium leakage.

Features: Good sealing performance, strong corrosion resistance, suitable for conveying media containing particles or corrosive substances, but the flow rate and pressure are usually lower than those of piston air pumps.

Second, the basis for selection

Application scenarios

Piston air pump: Suitable for scenarios requiring high-pressure output, such as air compressors, gas cylinder filling equipment, high-pressure cleaners, etc. Its high-pressure characteristics give it an advantage in the field of industrial gas compression.

Diaphragm air pump: Suitable for scenarios that require high sealing performance or corrosion resistance, such as sewage treatment, chemical transportation, food processing, etc. Its leak-free feature makes it stand out in fields with high environmental protection and hygiene requirements.

Medium characteristics

Piston air pump: It is suitable for conveying clean gas, but has poor adaptability to media containing particles or corrosive substances. Regular maintenance is required to prevent piston wear.

Diaphragm air pumps: They can transport media containing particles, high viscosity or corrosive substances. The flexibility of the diaphragm gives them an advantage when handling complex media.

Maintenance requirements

Piston air pump: It is necessary to regularly check the sealing performance of the piston, replace the lubricating oil, and maintain it frequently.

Diaphragm air pumps: Maintenance is relatively simple. The main concern is the wear of the diaphragm, and the replacement cycle is relatively long.

Noise and Energy Efficiency

Piston air pumps: They produce relatively high noise during operation and have low energy efficiency. They are suitable for industrial environments that are not sensitive to noise.

Diaphragm air pump: It has low noise and high energy efficiency, making it suitable for scenarios where noise and energy consumption are required.

Pressure and flow requirements

Piston air pump: It can provide higher pressure, but the flow range is narrower.

Diaphragm air pumps: They have relatively low pressure output, but a wider range of flow regulation, making them suitable for scenarios that require flexible adjustment.