Gas recovery charging and discharging device

The basic operating principle of the recovery system is based on the cryogenic liquefaction method. During the recovery process, the suction and compression capabilities of the compressor are utilized to draw SF₆ gas at a specific pressure from SF₆-containing electrical equipment into the compressor and compress it to a higher pressure. Simultaneously, leveraging the low evaporation temperature characteristic of R22 refrigerant, the high-temperature SF₆ gas is cooled down to its condensation temperature for liquefaction and storage. This continuous suction process is repeated across multiple SF₆ compressors operating in series until the target recovery pressure is achieved.
During charging or discharging operations, the vacuum pump of this device is first used to evacuate the SF6 electrical equipment (or gas cylinder) and its connecting pipelines. Then, either by utilizing the pressure difference or by leveraging the suction capability of the compressor to create a specific pressure differential, SF6 is charged into the SF6 electrical equipment from the device's storage container until the desired operating pressure is achieved. When filling cylinders is required, the aforementioned characteristics of R22 refrigerant are simultaneously employed to directly inject liquefied SF6 into the cylinders.
The purification function is executed simultaneously with the aforementioned charging and discharging functions.
The system is equipped with three oil separators – one installed at the vacuum pump outlet and two at the compressor outlet – to effectively remove any oil contamination present in the SF₆ gas.
The system circuit incorporates a drying filter to ensure the purity of the SF6 gas entering the storage container and to effectively remove moisture. The filter is equipped with a heating regeneration device that enables thermal regeneration under vacuum conditions, allowing the molecular sieve to be reused repeatedly.
The system is equipped with reliable safety protection devices; a high-pressure pressure controller is installed at the exhaust port of the SF6 compressor – when the exhaust pressure exceeds the set limit, it automatically stops the compressor's operation and restarts the compressor once the pressure decreases; a safety valve is installed on the storage container – in the event of over pressure, the safety valve opens automatically to discharge the gas and closes automatically once the pressure drops.