News

Diaphragm compressor diaphragm damage factors

The service life of the diaphragm is the main design basis of the diaphragm compressor. When the mechanical design, pressure and volume of the compressor meet the requirements, the service life of the metal diaphragm will determine the reliability of the compressor, and a reliable diaphragm will reduce maintenance costs. ,Increase production. The key factors affecting diaphragm breakage are as follows:

About the diaphragm

1. Mechanical properties A high-quality diaphragm should have excellent mechanical properties such as high tensile strength and HV hardness.

2. Diaphragm material The material of the diaphragm should be elastic and can obtain a longer anti-metal fatigue time

3. Chemical corrosion In the face of different gases, it is necessary to make complex adjustment of trace elements for corrosion.

About Diaphragm Compressors

1. Sealing structure The sealing structure of different manufacturers is different, which will lead to additional stress on the diaphragm due to poor sealing, which will shorten the life of the diaphragm.

2. Hydraulic pressure The piston pressure pushes the hydraulic oil to the diaphragm. Is there a problem with excessive pressure?

3. Membrane cavity curve The excellent membrane cavity curve is perfectly matched with the performance of the diaphragm. Failure to do so can result in stunted performance of the diaphragm, or premature failure.

4. Working temperature For diaphragm compressors used in hydrogen refueling stations, the exhaust temperature should not be higher than the standard of 135 degrees, otherwise hydrogen embrittlement and corrosion will occur.

quality of gas

1. Gas purity At present, the types of hydrogen are gray hydrogen, blue-cyan and green hydrogen. Both gray hydrogen and blue green are industrial by-products, and the gas impurities are different for different gas sources. It is easy to cause impact on the gas side of the diaphragm due to foreign matter during the compression process, which will cause premature damage to the diaphragm.

2. The water content of the gas causes great damage to the diaphragm

On-site operation process Please operate according to the manufacturer's standard operation manual. Wrong operation process can easily cause various problems. This will cause the diaphragm to break and stop the alarm.

1. Diaphragm material:

1) Mechanical properties of the material: Tongxinshang uses specially treated 177T as the diaphragm material, which has good mechanical properties.

2) The smoothness of the diaphragm: The roughness of the diaphragm surface will cause stress concentration and greatly affect the stress distribution of the diaphragm. The 177T diaphragm is cold rolled and polished to be smooth and free of impurities.

3) Thickness of diaphragm: The thickness of the material also affects the stress. The thickness of the diaphragm is inversely proportional to the stress. The standard thickness of the same company is 0.4mm/0.5mm. When the thickness is less than 0.4mm, the material will be difficult to handle and easy to deform. In addition, the too thin diaphragm is easy to break.

2. Diaphragm stress:

1) The curve of the cavity: The biggest factor affecting the stress of the diaphragm is the shape of the curve of the cavity. At present, there are single-exponential, double-exponential and triple-exponential curves in the country.

2) Torque: The rubber "O" ring seal, the tightening torque is small, the stress of the diaphragm is reduced, and the life of the diaphragm is improved.

3. On-site operation:

1) Compressed gas: Corrosive gas will reduce the life of the diaphragm, 177T has added trace elements and has anti-corrosion properties.

2) Cleanliness of the gas: Any fine particles mixed in the gas, once entering the cavity, will eventually accumulate at the edge of the cavity (close to the sealing surface), resulting in increased stress and a serious impact on the life of the diaphragm.

3) Frictional corrosion: This corrosion occurs between two objects under pressure. Mutual displacement will cause stress concentration and reduce this wear. Lubricating oil can be applied evenly (1-2 drops) on both sides of the intermediate piece. The 177T diaphragm has a Vickers hardness of HV400/600, and the wear and corrosion between the diaphragms are completely eliminated. , thereby increasing the life of the diaphragm.

4) Temperature: High temperature will also affect the diaphragm stress. High temperature will cause thermal stress to the diaphragm. High compression ratio will also generate heat. The compressed gas will have different effects. In short, it is necessary to reduce the temperature and prolong the life of the diaphragm.