This equipment is mainly suitable for bright annealing (recrystallization) and tempering of metal materials. During operation, the furnace bladder is vented into a nitrogen-based gas containing a small amount of hydrogen after being evacuated in a cold state. At the temperature required by the process, after heating and holding, the vacuum furnace is lifted out of the furnace and placed in a cooling pit. When the temperature drops below 120 ° C, the workpiece is opened and the furnace lid is opened to maintain the original color of the workpiece.
Large-scale pit furnaces and deep-well furnaces are generally used for heat treatment of large-diameter workpieces and large annular workpieces. They are suitable for annealing, quenching, and tempering heat treatment of extra-long and extra-long rod and shaft workpieces, and small deformation of vertical or hanging workpieces. Large-scale pit furnaces or deep-well furnaces are generally insulated by full-fiber furnace linings. Because large-sized pit furnaces have very large dimensions in the depth and diameter directions, in order to ensure uniform temperature at all points in the working area of the furnace, especially to reduce the temperature difference in the vertical direction, This type of well-type furnace is specially designed with heating elements. It not only adopts professional production of upper and lower sections, but also uses microcomputer programs to independently control each section with high precision. The furnace lining is energy-saving, and the empty furnace has a small loss, which saves 30-50% of electricity compared with the same period last year. Large-scale pit furnaces and deep-well furnaces can be used for high temperature, medium temperature and low temperature work, and can be used for annealing, quenching, tempering and other metal materials such as alloy steel, high chromium steel, high manganese steel and mechanical parts for heat treatment. Large shaft furnaces can reach a diameter of 6 meters, and deep shaft furnaces can reach a depth of 27 meters.