Pictured is a Glass Reflow Induction Heat System, designed and built by QM Systems to meet our customer’s requirement to produce Vacuum Tube Stems. This system is controlled by a Mitsubishi Heavy Industries PLC and HMI, with a menu style system. It features a 6-nest rotary indexing table, Ambrell Induction Heating Solutions Induction heater, EkoHeat 30 kW / 100 kHz induction heating and an EASYChill 22kW air-cooled water chiller.
The operator loads 6 pairs of carbon nests with a glass stem, powdered glass and a weight on top to secure the parts in place. Once loaded, the chamber is sealed to start the system cycle. A pair of nests index to station 1 and pneumatic cylinders actuate a pair of induction coils over the nests, heat soaking them to around 1000 degrees. Once soaked, the nests index to station 2 and pneumatic cylinders actuate a pair of top-hats over the nests, enclosing them before trickling nitrogen into the enclosures. This prevents the nests from oxidising whilst they cool down.
Once all 6 pairs of nests have been cycled through the two stations the chamber is filled with nitrogen. The chiller will activate whilst the rotary table continuously rotates, cooling the vacuum tube stems until they reach a temperature suitable for unloading.