The box-type quenching furnace is a periodic operation furnace suitable for heat treatment of rod and long shaft components. The structure of the box-type quenching furnace is a cylindrical deep well for the furnace body, with workpieces vertically loaded into the furnace for heating using a special crane. The fuel typically used is coal gas or oil. When electricity is the heat source, it is referred to as a well-type resistance furnace. Box-type quenching furnaces are usually installed below the factory floor level, but they can also be placed above the floor level, or half above and half below.
The names of box-type quenching furnaces include forced convection box-type quenching furnace, natural convection box-type quenching furnace, well-type gas carburizing furnace, and so on. Box-type quenching furnaces can be operated with gas or liquid fuel, as well as electric heating. When using gas fuel, there are typically multiple small-burner nozzles installed tangentially along the inner wall of the furnace chamber, evenly distributed in height in layers or in a spiral pattern to prevent the flame from directly impinging on the workpiece, ensuring uniform temperature inside the furnace. When used for low-temperature tempering or when oil is used as the softening material, a thin muffle wall is built inside the furnace chamber to separate the combustion space from the heating space, but box-type quenching furnaces with muffle walls consume less fuel.
