The equipment-variously referred to as a stainless steel mesh-belt bright furnace, stainless steel bright annealing furnace, powder metallurgy sintering furnace, or brazing furnace-is fundamentally the same unit; the differing names simply reflect the specific application.
The stainless steel tube bright annealing furnace employs a four-stage continuous heating system, with each stage featuring 12 heating elements capable of reaching temperatures up to 1150°C. Four stainless steel core tubes are positioned horizontally within the furnace to serve as annealing chambers; the tubes to be annealed pass through these core tubes while a hydrogen-rich atmosphere is simultaneously introduced. The furnace ensures uniform heating across all stages with excellent thermal efficiency. As the tubes pass through the core tubes, they cause no vibration or impact on the heating elements. The furnace features a fully enclosed structure without access doors-only the four core tubes run through the entire length-minimizing heat loss and ensuring superior thermal insulation.
To rapidly cool the annealed stainless steel tubes, the furnace is equipped with a two-stage cooling section utilizing four stainless steel cooling tubes. The tubes to be annealed and the protective gas pass through these cooling tubes, which are externally cooled by circulating water. Rapid cooling allows for the formation of a supersaturated solid solution, achieving the required hardness and surface brightness. (See the diagram for the cross-sectional view of the cooling section.) To facilitate storage and downstream processing, a specialized coiling mechanism is installed at the furnace outlet. This allows the annealed tubes to be coiled while a hydrogen protection system simultaneously feeds gas into the tube's inner bore to prevent oxidation. Thermocouples are installed in all four heating zones and connected to a control panel for automatic temperature regulation; the system also includes automatic pressure and temperature alarms, as well as timing control functions.
