Applicable scope of gas purification equipment

Helium is mainly used in medical, military, refrigeration, semiconductor, pipeline leak detection, high-precision welding, metal manufacturing, deep-sea diving, optoelectronic product production, balloon-borne, scientific research, military and other fields. The following is an analysis of helium resource users in combination with the main applications of helium resources.

(1) Nuclear magnetic resonance (low-temperature superconductivity) field

Magnetic resonance imaging (MRI) uses cryogenic superconducting magnet technology and needs liquid helium for cooling. According to statistics, MRI accounts for 34% of the global helium consumption, which is the end-use industry. Although the demand for nuclear magnetic resonance imaging equipment is decreasing in developed countries, the demand for nuclear magnetic resonance imaging equipment in developing countries is still growing strongly, thus maintaining the strong demand for liquid helium.

(2) Refrigeration (household appliances)

Helium is mainly used for leak detection of condenser, evaporator and pipeline system.

(3) Semiconductor and optical fiber

Helium is mainly used as the protective gas for the growth of germanium and silicon crystals in the semiconductor industry, as well as the cooling and protective atmosphere gas in the fabrication of optical fiber preforms and fiber drawing process.

Customization of nitrogen purification equipment

(4) Welding shielding gas

Purpose: When some metals are heated or melted, in order to prevent their reaction with oxygen and nitrogen in the atmosphere, inert atmosphere must be used for protection. A large amount of helium is consumed in metal welding. In inert gas shielded tungsten arc welding (TIG), molten tungsten, hot metal filler and welding area shall be protected with continuous helium or helium-argon mixture. The gas mixture used for shielded welding can be prepared with helium and argon in different proportions. According to the different welding process, welding wire and base metal to be welded, the composition of the mixture can be different. Generally, the helium content in the helium-argon mixture is 15% - 70%.

(5) Cryogenic engineering field

Purpose: Because of its chemical inertness and extremely low liquefaction point, helium is close to ideal gas behavior at all temperatures except extremely low temperature, and has high heat capacity per unit mass, low viscosity and high thermal conductivity, so helium is usually used as the working medium of closed cycle cryogenic refrigerator, the cooling medium of cryogenic superconducting magnets and superconducting cavities in national major scientific projects, and scientific research experiments in colleges and universities.

(6) Aerospace

Purpose: In the fuel system of rocket and space vehicle, helium is used to clean cryogenic fuel and oxidation storage tanks, and pressurize the upper space of the liquid level of cryogenic storage tanks to provide pressure for direct delivery of liquid hydrogen and liquid oxygen, or only provide net positive suction pressure for the infusion pump. Helium is often used as the working medium in the pneumatic control system. Before the launch of the rocket, in order to obtain high propulsion efficiency in the first few minutes of ignition, cryogenic helium has been used to precool the upper stage liquid hydrogen rocket engine. Liquid helium is also widely used in cryogenic radiation detectors and other special instruments in space exploration programs.

(7) Balloon carrier

Use: civil or military aerostats, airships, balloons and other filling gas.

(8) Automobile manufacturing

Purpose: Helium is used in the automobile airbag, in the leak detection of the automobile aluminum alloy hub, in the leak detection of the automobile air conditioner evaporator, compressor and condenser, and in the application of helium in the frame laser welding.

(9) Other fields

Physiological medicine, nuclear reactor, electric light source, metallurgy and metal processing technology, analysis and test of carrier gas, etc. This part of gas is generally not recycled.