The diaphragm pump, also known as the control pump, is a conveying machine widely used in various industrial fields. Through its unique structural design and working principle, it realizes the transportation of a variety of complex media and has become an indispensable part of modern industry. In this article, the working principle, classification, structural characteristics and application areas of diaphragm pumps will be introduced in detail to help better understand and apply this equipment.
I. The principle of diaphragm pump
There are many ways to classify diaphragm pumps. The following are two common classification methods:
The driving mechanism drives the diaphragm to perform reciprocating motion through mechanical transmission. Taking the common pneumatic diaphragm pump as an example, when compressed air enters the pneumatic motor, it pushes the piston to perform reciprocating motion.
The diaphragm cylinder head includes diaphragm, inlet and outlet check valves and other components. During the movement of the diaphragm, when the diaphragm moves to one side, the volume of the diaphragm chamber increases, the pressure decreases, and the medium is sucked in through the inlet check valve. When the diaphragm moves to the other side, the chamber volume decreases, the pressure increases, and the medium is discharged through the outlet check valve. In this way, the medium is transported.
II. The classification of the diaphragm pump
There are many ways to classify diaphragm pumps. The following are two common classification methods:
1. Classified by power source:
• Pneumatic diaphragm pump: The use of compressed air as the power source to drive the diaphragm back and forth through mechanical or hydraulic transmission.
• Electric diaphragm pump: The transmission mechanism is driven by an electric motor, which in turn drives the diaphragm to reciprocate.
• Hydraulic diaphragm pump: The use of liquid pressure as the power source to drive the diaphragm to perform reciprocating motion.
2. Classified by material:
• Plastic diaphragm pump: Suitable for conveying corrosive media.
• Aluminum alloy diaphragm pump: Light weight and good corrosion resistance.
• Cast iron diaphragm pumps: High strength and wear resistance.
• Stainless steel diaphragm pump: Suitable for conveying high temperature, high pressure or highly corrosive medium.
III. The features of the diaphragm pump
Diaphragm pumps have a variety of distinguishing features that make them widely used in several fields:
• Shaft seal-free design: There are no sliding parts (shaft seals) in contact with the liquid, so diaphragm pumps are highly safe from leakage due to seal wear.
• Strong conveying capacity: It can convey various corrosive, viscous and volatile liquids, such as acids, alkalis, organic solvents and petroleum products.
• Strong self-priming ability: some diaphragm pumps have good self-priming performance, which can pump the liquid and automatically remove the air in it.
• Simple structure: The structure of diaphragm pump is relatively simple, easy to install and maintain.
• Stable operation: The diaphragm pump will not generate sparks or overheat during operation, and its operation is stable and reliable.
IV. The common faults of diaphragm pumps
The diaphragm pump may have some faults during long-term use. The following are some common faults and their troubleshooting methods:
1. The pump does not work or operates very slowly:
• Check the filter or air filter at the air inlet for any foreign matter.
• Check air valve for sticking or wear, clean or replace if necessary.
• Check the condition of the sealing parts of the center body and replace them with new ones if they are severely worn.
2. Insufficient flow:
• Check the inlet and outlet valves for leakage. If there is leakage, repair or replace them.
• Check the diaphragm for damage and replace if damaged.
• Check whether the speed is too slow or the adjustment fails, and perform maintenance and adjustment if necessary.
3. Excessive noise:
• Check the pump body for looseness or damage, tighten or replace if necessary.
• Check bearings for wear or poor lubrication and replace or lubricate as necessary.
4. Leakage:
• Check whether the gasket or sealing ring is damaged or too loose, if so, replace or adjust it.
• Check whether the diaphragm and inner and outer clamps are clamped on the shaft. If they are loose, tighten them.
V. Applicable scenarios of diaphragm pumps
Diaphragm pumps play an important role in multiple scenarios due to their unique advantages and wide range of applications:
• Chemical industry: Used to transport various corrosive, viscous and volatile liquids, such as acids, alkalis, organic solvents, etc.
• Environmental protection field: used in environmental protection projects such as wastewater treatment and building sewage discharge to transport various sewage and sediments.
• Food industry: Used to transport food raw materials, sauces, etc. to ensure food hygiene and safety.
• Mining field: Used for drainage and transportation in mines, tunnels, etc.
• Other fields: Such as pharmaceutical, printing and dyeing, paper making and other industries in the liquid transportation work.
