Properties of SF6 Gas
Physical Properties of SF6 Gas
Pure SF6 gas is a colorless, odorless, basically nontoxic, nonflammable halogen compound. At 20 ℃and 0.1 MPa, the density is 6.0886 kg/m3, which is about 5 times the density of air. For ease of transportation and storage, SF6 gas usually exists in the cylinder in liquid form.
Chemical Properties of SF6 Gas
The chemical properties of SF6 gas are very stable, it does not burn in the air, does not support combustion, and does not react with water, strong alkali, ammonia, hydrochloric acid, sulfuric acid, etc. Below 150°C, SF6 gas is chemically inert, seldom soluble in water, and slightly soluble in alcohol. It has no chemical effect on metals and other organic materials commonly used in electrical equipment.
Is SF6 Gas Toxic?
The toxicity of sulfur hexafluoride gas mainly comes from five aspects.
1. Some toxic products are produced by sulfur hexafluoride gas in electrical equipment when the high-temperature arc acts.
2. The sulfur hexafluoride product is impure and contains toxic low sulfur fluoride, hydrogen fluoride, and other toxic gases when leaving the factory.
3. The sulfur hexafluoride gas and its decomposition products in electrical equipment react with electrodes (Cu-W alloy) and metal materials (AL, Cu) to generate some toxic products.
4. The decomposition product of sulfur hexafluoride gas in electrical equipment reacts chemically with the water in it to generate some toxic products.
5. The sulfur hexafluoride gas and its decomposition products in electrical equipment react with insulating materials to generate some toxic products.
Pure sulfur hexafluoride gas is non-toxic. However, under high current, some sulfur-containing low fluorides will be generated due to strong arc discharge. These substances have strong reactivity. When there is water and oxygen, they will further react with electrode materials and moisture, and decompose to produce toxic and highly toxic gases.
These toxic gases mainly damage the respiratory system of the human body. After poisoning, there will be adverse reactions such as colds, skin allergies, nausea and vomiting, and fatigue. More sub-serious consequences occur when inhaling large amounts.
What is SF6 Gas Recovery and Purification Device?
SF6 gas recovery and purification devices are used in the manufacture, use, operation, scientific research, and other departments of SF6 gas-insulated electrical equipment. The function of this equipment is to vacuum various electrical equipment, recover SF6 gas from electrical appliances used or tested, purify and process SF6 gas, then compress and store the gas in storage tanks, and recharge electrical equipment with SF6 gas. The SF6 gas recovery and purification charging and discharging device are suitable for SF6 switchgear and GIS combination appliances.
What is GIS?
GIS (Gas Insulated Switchgear) refers to the enclosed combination of electrical appliances of sulfur hexafluoride, also known as gas insulated switchgear. It is an organic combination of equipment other than transformers in a substation, including circuit breakers, isolating switches, voltage transformers, arresters, etc., through optimized design. Filled with insulating gas SF6 as insulating and arc extinguishing medium. GIS equipment has the most extensive application in the power industry.
What is the Working Process of the SF6 Gas Recovery and Purification Device?
1. Recovery of SF6 gas
SF6 is extracted from a gas chamber and automatically flows through the purification filter. Then, it is compressed, cooled, and purified by the SF6 compressor, and stored in the SF6 storage tank in liquid form under a certain high pressure.
2. SF6 switch vacuum
The gas in the electrical switch can be evacuated by using a vacuum pump, and the outlet of the vacuum pump leads to the atmosphere.
Fill the purified and dried SF6 from the storage tank back into the evacuated air chamber until the pressure in the air chamber reaches the set working pressure.
This part of the work can be done in two steps:
(1) With the help of the SF6 storage tank pressure, the gas is vaporized and flows to the SF6 switch until the predetermined inflation pressure is reached.
(2) When the pressure of the SF6 storage tank is balanced with the pressure of the SF6 switch, the compressor is used to pressurize and inflate until the predetermined inflation pressure is reached.
The SF6 gas recovery and purification device developed and produced by YUNENG can solve the problems of recovery, purification, and refilling of SF6 gas. If you would like more detailed product information, please contact us.