Box type furnace is a periodic operation furnace, which is suitable for heat treatment of rod and long shaft parts. The structure of the box type quenching furnace is: the furnace body is a cylindrical deep well, and the workpieces are vertically loaded into the furnace by a special crane for heating. The fuel used is usually gas and fuel oil. When electricity is used as heat source, it is called well type resistance furnace. The box type quenching furnace is generally placed below the ground level of the workshop, or above or below the ground level.

The name of box type quenching furnace includes: forced convection box type quenching furnace, natural convection box type quenching furnace, well type gas carburizing furnace, etc. The box type quenching furnace can be heated either by gas or liquid fuel or by electricity. When using gas fuel, there are usually several small energy burners, which are installed along the tangent direction of the furnace inner wall, and are evenly arranged in layers or in a spiral shape in height, so as to avoid the flame directly washing the workpiece and ensure the uniform temperature in the furnace. When it is used for low temperature tempering or oil as raw material, a thin muffle wall is built in the furnace to separate the combustion space from the heating space, but the fuel consumption of the box type quenching furnace with muffle wall is relatively low.