Different types of Hydrogen Compressors may use different sealing methods. The following is an overview of some common hydrogen compressors and their sealing methods:
1. Reciprocating hydrogen compressor
Reciprocating hydrogen compressors typically use methods such as packing seals or labyrinth seals.
Packing seal:
The packing seal is composed of multiple sealing rings, which are usually made of wear-resistant and corrosion-resistant materials such as polytetrafluoroethylene, graphite, etc.
Packing sealing prevents hydrogen gas leakage by tightly adhering to the piston rod. As the piston rod moves back and forth, the sealing ring will constantly wear out, so it needs to be checked and replaced regularly.
Maze seal:
Maze seals are composed of a series of parallel rings or grooves that form winding channels between them, thereby increasing the difficulty of gas leakage.
Maze seals mainly utilize the flow resistance of gas in the channel to reduce leakage, but cannot completely prevent gas leakage.
2. Centrifugal hydrogen compressor
Centrifugal hydrogen compressors typically use methods such as dry gas seals or floating ring seals.
Dry gas seal:
Dry gas seal is a non-contact seal that achieves sealing through gas dynamic effects.
The dry gas seal consists of a dynamic ring, a static ring, a spring, and a sealing ring. When the moving ring rotates, the sealing gas is sucked into the pressure groove of the moving ring, forming a thin gas film to prevent hydrogen gas leakage.
Dry gas seals have the advantages of small leakage, low frictional power consumption, and long service life, but require stable gas pressure and flow rate to control the sealing effect.
Floating ring seal:
Floating ring seal is a contact seal composed of a floating ring, spring, and sealing ring.
The floating ring maintains a certain gap with the shaft sleeve under the action of the spring, and a liquid film is formed between the floating ring and the shaft sleeve to prevent hydrogen gas leakage.
Floating ring seals are suitable for high temperature, high pressure, and highly corrosive media, but the sealing effect may be affected by the viscosity and temperature of the medium.
3. Other types of hydrogen compressors
In addition to reciprocating and centrifugal hydrogen compressors, there are other types of hydrogen compressors such as screw and slide compressors. These compressors typically use methods such as labyrinth seals, end face seals, or spiral groove seals to prevent hydrogen gas leakage.
Maze seal:
As mentioned earlier, labyrinth seals increase the difficulty of gas leakage through tortuous channels.
In screw and slide type hydrogen compressors, labyrinth seals are commonly used for sealing parts such as shaft ends and bearing housings.
End face seal:
End face sealing is a type of contact seal that prevents hydrogen gas leakage by ensuring a tight fit between the end faces.
End face seals are typically composed of two opposing end faces, which are typically made of wear-resistant and corrosion-resistant materials.
In screw and slide type hydrogen compressors, end face seals are commonly used for sealing between the rotor and stator.
Spiral groove seal:
Spiral groove seal is a non-contact seal that reduces gas leakage through the throttling effect of the spiral groove.
Spiral groove seals are commonly used for sealing the rotor end and bearing housing of screw hydrogen compressors.
In summary, different types of hydrogen compressors use different sealing methods, and the selection of these methods depends on factors such as the type of compressor, working pressure, medium characteristics, and working environment. In practical applications, it is necessary to choose the appropriate sealing method according to the specific situation, and regularly inspect and maintain the sealing device to ensure the normal operation and safety of the compressor.
There are significant differences between different sealing methods, each with unique characteristics, applicable scenarios, and advantages and disadvantages. Here is a comparison of several common sealing methods:
1. Static sealing and dynamic sealing
Static sealing
Definition: The sealing of parts in contact with stationary components, such as the sealing of the body and cover plate.
Materials: Metal (copper, iron, stainless steel, aluminum, etc.) or non-metal materials (rubber, plastic, etc.).
Technology: flat seal, tooth groove seal, O-ring seal, V-ring seal, etc.
Features: The sealing surface has high precision, generally requiring a minimum of 0.2 μ m, while also requiring the sealing surface to meet the requirements for parallelism, roundness, and straightness.
Dynamic sealing
Definition: The seal between rotating or moving parts and stationary parts, such as the seal between pistons and cylinder liners.
Materials: Polymer materials with low gas permeability and lubricating oil.
Technology: circular seal, bidirectional seal, friction seal, etc.
Characteristics: The precision requirement for sealing is higher than that of static sealing, generally requiring a minimum of 0.1 μ m.
2. Comparison of Specific Sealing Methods
O-type seal
Structure: Composed of a rubber ring with a circular cross-section.
Application: Usually located on the piston, used to seal liquids and gases.
Advantages and disadvantages: Low price, easy to replace, but requires more frequent replacement.
Mechanical seal
Structure: Composed of a rotating part and a stationary part.
Application: Widely used in rotating equipment, such as reciprocating compressors and centrifugal compressors.
Advantages and disadvantages: It can meet complex working conditions such as high speed, high pressure, and high temperature, but it is expensive and requires regular maintenance.
Piston ring seal
Structure: Composed of a rubber sealing ring, fixed on the piston.
Application: Commonly used in reciprocating compressors.
Advantages and disadvantages: Long service life, low price, but requires frequent replacement.
Honeycomb seal
Structure: Made of metal or polymer material, including a sealing seat and a sealing head.
Application: It can effectively prevent gas and oil leaks and improve the performance of reciprocating compressors.
Advantages and disadvantages: It can improve the efficiency and service life of reciprocating compressors, suitable for small and medium-sized reciprocating compressors.
Maze seal
Structure: A series of complex channels and obstacles are used to slow down the speed of gas leakage, thereby achieving a sealing effect.
Application: impeller cover sealing, inter stage sealing, and shaft end sealing in centrifugal compressors.
Characteristic: Complex structure, but reliable sealing effect.
Dry gas seal
Principle: A stable gas film is formed between the sealing surfaces to prevent medium leakage.
Applications: Screw compressors and circulating hydrogen compressors, etc.
Features: Fast sealing speed, sensitive to shaft displacement, requiring strict control of operating parameters.
3. Summary
Different sealing methods have their own advantages and disadvantages, and the choice of sealing method depends on the specific application scenario and operating conditions. For example, in situations where high pressure and high temperature are required, mechanical seals may be more suitable; In situations where gas leakage prevention is necessary, dry gas seals may be more effective. Therefore, when choosing a sealing method, various factors need to be comprehensively considered, including the operating conditions of the equipment, the properties of the medium, the reliability and economy of the seal, etc.
