When using tungsten wire for glass heating, the following specifications must be followed to ensure safety and efficiency:
1. Material selection:
1.1 Use high-purity tungsten wire (purity ≥99.95%) to ensure oxidation resistance and mechanical strength at high temperatures.
1.2 According to the heating temperature and glass type, select tungsten wire of appropriate diameter to avoid overheating or breakage.
2. Working environment:
2.1 Tungsten wire is easy to react with oxygen at high temperatures and needs to be used in a vacuum or inert gas (such as argon, nitrogen) environment to prevent oxidation.
2.2 Ensure that the heating furnace or equipment is well sealed, and the air pressure is controlled below 10^-2 Pa (vacuum) or the purity of the inert gas is ≥99.99%.
3. Current and temperature control:
3.1 The heating temperature of tungsten wire can reach 2500-3000°C. Constant current or constant voltage power supply should be used to gradually increase the current to avoid instantaneous overload.
3.2 Equipped with temperature monitoring system (such as infrared thermometer) to ensure uniform heating of glass and prevent local overheating and cracking.
3.3 Refer to the relationship between tungsten wire resistivity and temperature to reasonably set the current to prevent burning.
4. Installation and fixation:
4.1 Tungsten wire should be evenly wound or fixed on high temperature resistant ceramic or quartz bracket to avoid contact with glass or other conductive materials.
4.2 Ensure that the tension of tungsten wire is moderate. Too tight may break easily, and too loose may cause poor contact or short circuit.
5. Operation safety:
5.1 Operators need to wear protective glasses and high temperature resistant gloves to avoid high temperature radiation and glass fragments.
5.2 Regularly check the aging of tungsten wire. If the surface is discolored, brittle or cracked, replace it in time.
5.3 Before powering on the equipment, make sure that the grounding is good to prevent leakage.
6. Glass heating process:
6.1 Set the heating rate and insulation time according to the glass type (such as borosilicate glass, quartz glass) to prevent excessive thermal stress.
6.2 Usually the heating rate is controlled at 5-10°C/min, and the annealing process is used during cooling to avoid stress accumulation in the glass.
7. Maintenance and storage:
7.1 Tungsten filaments are stored in a dry, oxygen-free environment to prevent moisture or oxidation.
7.2 Check the equipment after use and clean the residue to ensure that there are no impurities that affect the heating effect when it is used next time.
