SF6 gas vacuumizing and filling device working principle
It has comprehensive functions such as recovery, charging and discharging, purification, vacuumizing, storage, and cylinder filling, with a relatively complete system. 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.
The basic working principle of the recovery device is the freezing liquefaction method. During recovery, the suction and compression characteristics 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 compressors operate in series, reaching the final recovery pressure.
During charging and discharging, first use the vacuum pump of this device to vacuumize the SF6 electrical equipment (or cylinders) and connecting pipelines, then directly use the pressure difference or use the suction of the compressor to create a certain pressure difference to fill the SF6 from the device's storage container into the SF6 electrical equipment until the required working pressure is reached. When cylinder filling is needed, the characteristics of the R22 refrigerant as mentioned above are simultaneously utilized to directly fill the liquefied SF6 into cylinders.
The purification function is completed simultaneously when the above recovery, charging, and discharging functions are performed.
SF6 gas vacuumizing and filling 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 small size facilitate movement and use.
3. Efficient filtration and maintenance-free system greatly ensures the quality of recovered SF6 gas.
4. Built-in phase sequence protector eliminates concerns 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 without the need for external water source.
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 elements with automatic compensation performance.
11. Built-in solenoid valve power-off protection function prevents oil return due to power failure of the vacuum pump or motor seizure.
Main functions:
(1) Vacuumize and measure the vacuum degree of the device itself, electrical equipment, storage tanks, etc.
(2) Recover SF6 gas from electrical equipment.
(3) Dry and purify the recovered and refilled SF6 gas.
(4) Refill SF6 gas into electrical switches.
(5) Compress and store SF6 gas in liquid form.
Main technical parameters
1. Recovery
Initial recovery pressure ≤0.8MPa
Final recovery pressure ≤50KPa
Recovery time: for 1 m3 SF6 gas volume at initial pressure 0.8MPa, recovered to final pressure 50KPa, recovery time is less than 2.5 hours.
2. Charging
For 1 m3 SF6 gas volume at initial pressure 133Pa, charged to 0.8MPa, charging time is less than 0.8 hours.
3. Vacuumizing
The ultimate vacuum degree of the device is less than or equal to 10 Pa
For 1 m3 SF6 gas volume at initial pressure 0.1MPa, vacuumized to 133Pa, the required time is less than 1.0 hour.
4. Storage
Storage container volume 0.05m3
Nominal liquid storage capacity 50kg
Storage pressure 3.8 MPa
5. Purification
