SF6 Gas Vacuum Pumping Device Working Principle and Structural Features:
It has comprehensive functions such as recovery, charging and discharging, purification, vacuum pumping, storage, and cylinder filling. The system is relatively complete; refer to Appendix 1 for the system diagram. The series connection or switching of each function is mainly accomplished through the electric control box and ball valves concentrated on one side of the panel for operation.
The basic working principle of the recovery device is to adopt the freezing liquefaction method. During recovery, the suction and compression properties of the compressor are used to draw SF6 gas at a certain pressure from SF6 electrical equipment into the compressor and compress it to a higher pressure. At the same time, utilizing the low evaporation temperature characteristics of R22 refrigerant, the higher-temperature SF6 gas is cooled to the condensation temperature for liquefaction and storage. This continuous suction is carried out until the SF6 compressor operates in series until the final recovery pressure is reached.
During charging and discharging, first, the vacuum pump of this device is used to evacuate the SF6 electrical equipment (or cylinders) and connecting pipelines. Then, directly using the pressure difference or utilizing the suction of the compressor to create a certain pressure difference, the SF6 in the device's storage container is charged into the SF6 electrical equipment until the required working pressure is reached. When cylinder filling is needed, the aforementioned characteristics of R22 refrigerant are simultaneously utilized to directly fill the liquefied SF6 into the cylinders.
The purification function is completed simultaneously when the above recovery, charging, and discharging functions are performed.
Three oil separators are installed in the system, one at the outlet of the vacuum pump and two at the outlet of the compressor, to effectively remove the oil carried by the SF6 gas.
Dry filters are installed in the system circuit to ensure the purity of the SF6 entering the storage container and effectively remove moisture. The filter is equipped with a heating regeneration device, which can be heated and regenerated under vacuum, allowing the molecular sieve to be reused.
The system is equipped with reliable safety protection devices. A 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's operation and restart it after the pressure drops. A safety valve is installed on the storage container; once overpressure occurs, the safety valve automatically opens to release gas and closes automatically after the pressure drops.
In addition, the system is also equipped with a total of seven monitoring and control instruments, including one vacuum gauge installed at the recovery inlet, with a DN8 valve installed before the vacuum gauge for observation when needed; five pressure gauges installed at the recovery inlet, the SF6 compressor exhaust port, the refrigeration compressor suction and discharge ports, and the storage container; and one thermometer set on the refrigeration system, using a temperature bulb to sense the temperature of the liquid SF6.
SF6 Gas Vacuum Pumping Device Technical Features
1. Built-in filtration and adsorption system can adsorb impurities, moisture, decomposition products, and oil in SF6 gas.
2. Integrated design and smaller size facilitate movement and use.
3. Efficient filtration and maintenance-free system greatly ensure the quality of recovered SF6 gas.
4. Built-in phase sequence protector eliminates worries about reverse rotation of the main unit due to phase sequence errors at any time.
5. All electrical systems use high-quality brands.
6. High-quality casters greatly protect the floor paint and reduce the labor required for pushing.
7. The whole machine is air-cooled, no external water source needed.
8. Built-in temperature protection system can work normally even at -20 degrees Celsius.
9. Built-in drying and heating system ensures that after the desiccant is saturated, it can be activated and regenerated by heating through the equipment, thus eliminating the need to replace the desiccant.
10. All ball valves are sealing components with automatic compensation performance.
11. Built-in solenoid valve power failure protection function prevents oil backflow due to power failure or motor seizure of the vacuum pump.
