What is the Sulfur hexafluoride (SF6)?
Sulfur hexafluoride (SF6) is a synthetic fluorinated compound with an extremely stable molecular structure. It is a colorless, odorless, non-toxic, non-corrosive, non-flammable, non-explosive gas at normal temperature and pressure. It is liquid at low temperature and pressure, and becomes white solid after freezing.
What the main application of Sulfur hexafluoride (SF6)?
Because of its unique dielectric properties, electric utilities rely heavily on SF6 in electric power systems for voltage electrical insulation, current interruption, and arc quenching in the transmission and distribution of electricity.
Sulfur hexafluoride (SF6), when sealed inside power transmission and distribution (T&D) equipment, insulates switchgears, circuit breakers, and disconnectors by quenching dangerous arcs. This stable and nontoxic gas, which has excellent dielectric strength, is a key component in a power plant’s safety and efficiency.
SF6 is used in the electrical industry as a gaseous dielectric medium for high-voltage sulfur hexafluoride circuit breakers, switchgear, and other electrical equipment, often replacing oil-filled circuit breakers (OCBs) that can contain harmful polychlorinated biphenyls (PCBs). SF6 gas under pressure is used as an insulator in gas insulated switchgear (GIS) because it has a much higher dielectric strength than air or dry nitrogen. The high dielectric strength is a result of the gas's high electronegativity and density. This property makes it possible to significantly reduce the size of electrical gear. This makes GIS more suitable for certain purposes such as indoor placement, as opposed to air-insulated electrical gear, which takes up considerably more room.
Gas-insulated electrical gear is also more resistant to the effects of pollution and climate, as well as being more reliable in long-term operation because of its controlled operating environment.
Sulfur hexafluoride electrical equipment has a wide range of application, the maintenance period of sulfur hexafluoride electrical equipment is long, it is easy to maintain, and takes up little space.
Why do we need to recycle SF6?
1. SF6 is very expensive;
2. SF6 is a major greenhouse gas with high global warming potential listed in the Kyoto protocol, and its global warming potential is 22,800 times than CO2;
3. When SF6 gas contains moisture, it will cause the following hazards to electrical equipment:
(1) In the presence of moisture, SF6 decomposition products undergo a hydrolysis reaction, which hinders the recombination of SF6 decomposition products, reduces the recovery strength of SF6 media, and thereby reduces the insulation characteristics of the equipment;
(2) Intensified hydrolysis of low fluoride and decomposition of metal fluoride. The produced fluorinated sulfurous acid and hydrofluoric acid are highly toxic, which is very harmful to the human body, and will also corrode electrodes and insulating materials;
(3) It will cause condensation in the equipment. Because the moisture in the gas exists in the form of water vapor, when the temperature drops, it may condense inside the equipment and adhere to the surface of the equipment such as the surface of the electrode and insulator, which may easily cause surface discharge (flashover) and cause accidents;
(4) If fluorinated sulfurous acid and hydrofluoric acid are put into the atmosphere, they will pollute the environment.
4. A leak in gas-insulated equipment means there is less gas to protect it from the effects of electrical arcs. The results are lost signals, short circuits, malfunctions, and, ultimately, equipment failure that compromise safety and operations. Even a 10% gas loss can permanently damage insulators, shields, arcing contacts, and main contacts.
With equipment failure comes repairs and replacements, expensive in terms of both time and money. There could also be property damage, such as fires, and extended power outages resulting from poorly insulated equipment — potentially a public relations nightmare.
How to Avoid SF6 Gas Hazards?
The best way to avoid SF6 gas hazards is to continually monitor gas-insulated equipment for both quantity (to detect leaks) and quality (for current gas conditions). Then, when the gas has dropped below a certain level of purity, technicians can clean it. Here are just a few of FUOOTECH’s innovative SF6 gas solutions for greater safety and efficiency:
Model FT-LD Portable Dew Point Meter is researched and designed by using imported high-precision dew point sensor and latest digital circuit control technology, which is the intelligent precision instrument to measure the moisture content of the SF6 gas.
Model FT-LDZ Portable SF6 Purity, Decomposition and Dew Point Tester integrates SF6 micro-water detector, SF6 purity tester, and SF6 decomposition analyzer as one. One time field measurement can complete the three detections, greatly save the gas in the device, which can save 2/3 of gas usage, while reduce the user’s workload and improve work efficiency. This comprehesive SF6 gas analyzer can test dew point, micro-water content (ppm), SF6 purity, concertration of SO2, H2S, CO (optional) and HF conent (optional), as well as clearly display the temperature, humidity, time and date, etc. on LCD screen.
Series FTHS SF6 Gas Handling System is an all-in-one gas servicing unit that vacuuming, refills, cleans, recovers, and stores SF6 gas. It has effective safety controls for the highest level of performance, which virtually eliminates operating errors and fugitive SF6 gas emissions. It features advanced design, full function and compact structure with simple operation.
For over 20 years, FUOOTECH Group has been the preferred gloable supplier of devices and equipment for emission-free SF6 gas analyzing and handling. Meeting our clients‘requirements for first-class products and services, consistently and without any compromises, is our declared goal.
For more information about our comprehensive portfolio of SF6 gas solutions, welcome to visit related product webpages or contact product specialists.
