The SF6 gas recovery device has comprehensive functions such as recovery, charging and discharging, purification, vacuuming, storage, and bottle filling, and the system is relatively complete. The series connection or switching of each function is mainly completed by operating the electric control box and ball valve concentrated on one side of the panel.
The basic working principle of the SF6 gas recovery device is to use the refrigeration liquefaction method.
During recovery, the suction and compression properties of the compressor are used to suck the SF6 gas with a certain pressure in the SF6 electrical equipment into the compressor, and compress it to a higher pressure. At the same time, using the low evaporation temperature characteristics of R22 refrigerant, the higher temperature SF6 gas is cooled to the condensation temperature for liquefaction and storage. In this way, it is continuously pumped to the SF6 compressor running in series until the final recovery pressure is reached.
When charging and discharging, first use the vacuum pump of the device to vacuumize the SF6 electrical equipment (or steel cylinder) and connecting pipelines, and then directly use the pressure difference or the suction of the compressor to cause a certain pressure difference to store the device in the storage container. The SF6 inside is charged into the SF6 electrical equipment until the required working pressure is reached. When the bottle needs to be filled, the liquefied SF6 is directly filled into the steel cylinder by using the characteristics of the R22 refrigerant as mentioned above. The purification function is completed synchronously when the above-mentioned recycling, charging and discharging functions are completed. Two oil separators are installed in the system, which are respectively installed at the outlet of the compressor to effectively remove the oil contained in the SF6 gas. A drying filter is set in the system loop to ensure the purity of SF6 entering the storage container and effectively remove water. The filter is equipped with a heating regeneration device, which can be heated and regenerated under vacuum, and the molecular sieve can be used repeatedly.
There is a reliable safety protection device in the SF6 gas recovery system. The high-pressure pressure controller is installed at the exhaust port of the SF6 compressor. Once the exhaust pressure exceeds the limit value, it will automatically stop the compressor and restart after the pressure drops. Compressor; The safety valve is installed on the storage container. Once the overpressure safety valve opens automatically to discharge the gas, it automatically closes after the pressure drops. In addition, there are seven monitoring instruments and control instruments in the system, one of which is a vacuum gauge, which is installed at the recovery air inlet of the device, and a DN8 valve is installed in front of the vacuum gauge, which can be opened when it needs to be observed; five pressure gauges It is only installed on the recovery air inlet, the SF6 compressor discharge port, the refrigeration compressor suction and discharge port and the storage container; a thermometer is set on the refrigeration system, and the temperature bulb is used to sense the temperature of the SF6 liquid.
The inlet of the vacuum pump in the system is equipped with an electromagnetic vacuum belt charging valve, which is connected to the same power supply as the vacuum pump. When the pump stops working, the valve can automatically close the vacuum system and fill the air into the pump cavity through the inlet of the pump. This avoids the backflow of pump oil from contaminating the vacuum system. The refrigeration system in the system is set by the high and low pressure pressure controller to adjust the inlet and outlet pressure of the refrigeration compressor. once exceeded
The limit range will automatically cut off the work of the refrigeration compressor. When the low pressure is disconnected, the pressure rises or the high pressure is disconnected, and the compressor is restarted after the pressure falls.
The overall structure, the SF6 gas recovery device adopts the hand-push mobile type, which can be used under normal indoor and outdoor environmental conditions. The system of this device is relatively complex, consisting of vacuum pump, SF6 compressor, refrigeration system, storage container, pipeline, various valves, instruments and other accessories. The electric control box, operating valves and monitoring instruments are all concentrated on one side panel and have process instructions, so it is convenient and clear to use.