1. Preliminary preparation of the storage tank for perlite filling
1) Install the perlite filling devices on the explosion-proof device port and 4 perlite filling ports.
2) Install a vacuum valve on the vacuum port, and connect it with the vacuum pump with a metal hose.
3) Connect perlite filling devices with hose.
4) Use a vacuum pump to evacuate the interlayer to 100 to 150 Pa.
2. Pre-filling of perlite
1) When the vacuum degree of the interlayer reaches 100 to 150 Pa, first open the valve of the perlite filling device on the right side for filling of perlite for 100 seconds and close the valve. Subsequently vacuum for 30 minutes and fill for 100 seconds and repeat this step for a total of 15 times. Then, move to the next filling port for the same step for 15 times.
2) By analogy, when the filling at the left filling port is completed, and the volume of perlite filled will reach about 1.9 times.
3. Late filling of perlite
1) Install the perlite pressurized tank on the first perlite filling device on the right side. After 30 minutes of vacuuming each time, increase the pressure of the pressurized tank to 0.4 MPa and press the perlite into the interlayer. Then vacuum for 30 minutes each time and fill with perlite for 70 seconds, and repeat the step for 3 times.
2) Repeat the steps to fill the other filling ports. When completed, the volume of perlite filled will reach about 2.2-2.3 times.
4. Interlayer perlite sealing and cutting
1) Install the nitrogen injection device and fill the interlayer vacuum with nitrogen.
2) Remove the vacuum valve and clean the sealing surface, and re-install the vacuum valve.
3) Remove the perlite filling devices, clean the sealing surface of the explosion-proof device and install the sealing cover.