SF6 gas Introduction

sf6

SF6 gas has a history of over a century. It is a man-made inert gas synthesized in 1900 by two French chemists, Moissan and Lebeau. Around 1940, the US military used it in the Manhattan Project.

SF6 is a highly electronegative gas. Its molecules readily adsorb free electrons to form large negative ions, weakening the collisional ionization process in the gas. Therefore, its electrical insulation strength is very high, approximately 2.5 times that of air in a uniform electric field.

SF6 gas Used In electrical equipment

Since the mid-1960s, SF6 has been widely used as an insulating medium in high-voltage electrical equipment. SF6 gas-insulated fully enclosed switchgear occupies a much smaller area than conventional open-type high-voltage power distribution equipment, and its operation is unaffected by external weather and environmental conditions. Therefore, it is widely used not only in ultra-high voltage and extra-high voltage power systems but has also begun to be used in distribution networks.

It is mainly used for arc extinguishing in high-voltage switches and as an insulating material in large-capacity transformers and high-voltage cables. SF6 can be used as a gaseous insulating material in nuclear particle accelerators and X-ray equipment for surge arresters. Due to its good chemical stability and non-corrosiveness to equipment, it can be used as a refrigerant in the refrigeration industry (operating temperature between -45℃ and 0℃). SF6 has a high stopping ability for alpha particles, so it also has applications in radiochemistry. It can also be used as a desorbent to replace oxygen in coal dust from mines.

Why Say SF6 gas is Harmful

The most significant and serious problem with SF6 gas is its environmental pollution.

SF6 gas has an extremely strong greenhouse effect. One kilogram of SF6 gas has a greenhouse effect equivalent to 23,500 kilograms of carbon dioxide. It is currently the substance with the strongest greenhouse effect. The Kyoto Protocol explicitly prohibits the emission of SF6 gas.

SF6 can persist in the atmosphere for up to 3200 years. For example, the SF6 we emit today will exist on Earth for thousands of years.

The decomposition products of SF6 gas under high-voltage electric arcs have a destructive effect on the ozone layer.

SF6 gas itself is non-toxic, but it decomposes under high voltage and heat in electrical equipment, producing decomposition products. These products react with moisture, air, and oxygen to generate many toxic substances. These toxic substances are far more toxic than phosgene, and have a strong irritant and corrosive effect on the human respiratory tract, while also being corrosive to the metal parts and insulating materials of equipment.

Replacement Of SF6--vacuum Circuit Breaker

ZW7-40.5 Highland Outdoor Vacuum Circuit Breaker

1. Rated Voltage: 40.5kV
2. Operating Mechanism: Modular operating mechanism.
3. Installation Method: Fixed installation with outdoor support.
4. Product Compliance with Standards: GB/T1984-2014, GB/T11022-2011.
5. Product Advantages: E2-C2-M2 performance, easy maintenance, standardized outdoor design, wide applications range.

zw7 vcb replacement of sf6