Rapid Recovery Technology of SF6/N2 Mixed Insulation Gas in Electrical Equipment

Abstract

SF6 mixed gas is widely used as an insulation and arc extinguishing medium in electrical equipment in cold regions of northern China. Due to its low liquefaction temperature, existing gas recovery technologies are unable to achieve efficient and rapid recovery of SF6/N2 mixed insulation gases. In response to this challenge, a two-stage membrane separation and recovery technology has been proposed, which can efficiently and quickly separate SF6 and N2 from the mixed gas. The volume fraction (V/V) of obtained product SF6 gas reaches 90%, and the use of compression and refrigeration units can achieve rapid filling of 50 m3/h mixed gas. At the same time, the enrichment and recovery of trace SF6 gas in the exhaust gas are achieved. After enrichment, the volume fraction (V/V) of SF6 gas reaches 92%, and the volume fraction (V/V) of SF6 gas in the emptied mixed gas is 600 μL/L, far below the national standard value, solving the problems in actual production.