When an oxygen concentrator compressor operates under high-pressure conditions, seal leakage poses a direct threat to oxygen purity and equipment safety. Oxygen is a strong oxidizing agent; leakage not only leads to a decrease in oxygen purity but may also cause fire or explosion risks. Therefore, a multi-dimensional protection system must be constructed, encompassing sealing materials, structural design, pressure control, and monitoring systems.
The selection of sealing materials is a core challenge under high-pressure conditions. Traditional rubber or ordinary plastic seals are prone to oxidative decomposition in high-pressure oxygen environments, generating particulate matter that contaminates the oxygen flow path. Therefore, special materials that are high-pressure resistant and oxidation-resistant, such as polytetrafluoroethylene (PTFE) or perfluoroether rubber (FFKM), are required. These materials have low permeability and chemical stability, effectively blocking oxygen molecule penetration. Simultaneously, metal seals require surface passivation treatment to form a dense oxide film to reduce oxygen adsorption and reaction.
The sealing structure design must balance rigidity and elasticity. Under high-pressure conditions, seals must withstand enormous pressure without permanent deformation, while maintaining sufficient elasticity to compensate for gap changes caused by thermal expansion or vibration. For example, a double-layer sealing structure is employed, with an inner layer of rigid metal skeleton providing support and an outer layer of soft elastomer for a tight seal. Furthermore, the stepped sealing groove design guides the oxygen pressure distribution evenly, preventing localized stress concentration that could lead to seal failure.
Pressure control and differential pressure management are key technologies for preventing leaks. Under oxygen operation conditions, a precise pressure regulation system is needed to maintain a small differential pressure between the sealing chamber and the process chamber. Nitrogen is typically used as a buffer gas to establish a pressure barrier in the sealing chamber that is slightly higher than that in the process chamber. For example, when the nitrogen pressure in the sealing chamber falls below a set value, the system automatically triggers an alarm and interlocks to shut down, preventing oxygen backflow. Simultaneously, the pressure reducing valve must precisely control the nitrogen pressure fluctuation range to avoid fatigue damage to the seals due to sudden pressure changes.
Dynamic sealing technology can handle vibration and thermal deformation under high-pressure conditions. During compressor operation, shaft vibration or temperature changes cause dynamic changes in the sealing gap, which traditional static seals cannot adapt to. Therefore, floating sealing rings or hydraulic compensation sealing technology are required, using springs or hydraulic devices to adjust the seal position in real time, ensuring a constant tight fit with the rotating shaft. For example, some high-pressure compressors use carbon ring seals. Utilizing the self-lubricating properties and thermal stability of the carbon rings, a stable liquid film is formed under high pressure differentials, reducing friction and improving sealing performance.
Monitoring and early warning systems are the last line of defense for ensuring seal reliability. By installing pressure sensors, temperature sensors, and leak detection probes at the sealing points, changes in pressure, temperature, and oxygen concentration in the sealing cavity are monitored in real time. When an anomaly is detected, the system immediately activates an audible and visual alarm and interlocks to close the compressor's intake valve, preventing the leak from escalating. Simultaneously, historical data recording can track the trend of seal performance degradation, providing a basis for preventative maintenance.
Maintenance strategies must be matched with sealing technology. The replacement cycle of high-pressure seals should be shortened according to actual operating conditions to avoid increased leakage risk due to material aging. Special tools must be used when disassembling seals to prevent scratching the sealing surface. Strict cleaning and dimensional checks must be performed before installation to ensure that the sealing gap meets design requirements. Furthermore, regular airtightness tests should be conducted on the sealing system, using high-precision equipment such as helium mass spectrometers to detect even minor leaks, eliminating potential problems at their inception.
Controlling leaks in oxygen concentrator compressors under high-pressure conditions requires a comprehensive approach, encompassing material selection, structural design, pressure management, dynamic compensation, monitoring and early warning, and maintenance strategies. Through the synergistic effect of multiple technologies, a multi-layered protection system, from microscopic molecular barriers to macroscopic system interlocks, can be constructed to ensure oxygen purity and equipment safety, meeting the stringent requirements of medical, industrial, and other fields for highly reliable oxygen supply.
