For the necking treatment of quartz glass tube, the glass tube shall be installed on the tube clamping device; Turn on the switch of the corresponding station motor and adjust it to the appropriate speed to rotate the glass tube; Wear thermal insulation gloves and point the flame gun nozzle with adjusted flame to the appropriate position of the glass tube; Wear protective glasses and quickly close the flame gun when observing the inward shrinkage and deformation of the heating part of the glass tube; Remove the glass tube to prepare for loading the sample in the next step.
When necking the glass tube and packaging the sample, the flame burning point must be selected at a sufficient distance from the glass tube joint. It is recommended to maintain a palm width (about 8-250px) to avoid excessive temperature of the glass tube joint caused by heat conduction, which will affect the service life of the O-ring. Fluorine rubber is recommended to be used for the O-ring. Put the sample into the quartz glass tube, and disassemble the isolation valve, tube clamping device, necked glass tube, sealed glass column, clamp... In sequence; Load the sample and keep the distance between the sample and the necking 20-25mm to avoid flame burning to the sample; When the powdered sample is loaded, keep the part above the necking clean.
Furthermore, the sample is encapsulated in the test tube, installed on the rotating tube sealing device, and the clamp is connected; Close the extraction baffle valve of the corresponding station; Start the vacuum pump for air extraction; Slowly open the baffle valve of the corresponding station and pump the glass tube to the limit vacuum of the pump unit; Turn on the motor switch of the corresponding station and adjust it to the appropriate speed; Wear thermal insulation gloves, ignite and align the flame with the glass column for burning; Wear protective glasses, watch the glass tube and glass column melt together, and quickly turn off the flame.
1. The softening point temperature of high temperature resistant quartz glass is about 1730 ℃, which can be used at 1100 ℃ for a long time and 1450 ℃ for a short time.
2. Corrosion resistance except hydrofluoric acid, quartz glass hardly reacts with other acids. Its acid resistance is 30 times that of ceramics and 150 times that of stainless steel, especially its chemical stability at high temperature. Quartz glass instrument is unmatched by any other engineering material.
3. Good thermal stability, the thermal expansion coefficient of quartz glass is small, and the quartz glass instrument can withstand drastic temperature changes. The quartz glass will not burst when heated to about 1100 ℃ and put into normal temperature water.
4. Good light transmission performance. Quartz glass has good light transmission performance in the whole spectral band from ultraviolet to infrared. The visible light transmittance is more than 93%, especially in the ultraviolet spectral region, the larger transmittance can reach more than 80.
5. Good electrical insulation. The resistance of quartz glass is 10000 times that of ordinary glass. It is a good electrical insulation material and has good electrical properties even at high temperature.