What are the differences between box-type resistance furnaces and pit-type resistance furnaces?
Box-type resistance furnaces and pit-type resistance furnaces have some common features. Most of the internal heating types are made of refractory materials and thermal insulation materials. The internal atmosphere is mostly air under normal pressure, but there are also external heating and well-type furnaces and argon. , nitrogen or vacuum state, the operating temperature is generally below 1200 ° C. The following is a brief introduction to the difference between the two furnaces:
The box-type resistance furnace is shaped like a rectangular box, mainly composed of two parts: the furnace body and the control box. The box-type resistance furnace generally works under natural atmosphere conditions, mostly in the way of internal heating, and is made of refractory materials and thermal insulation materials. Furnace lining. It is used for normalizing, annealing, quenching and other heat treatment of workpieces and other heating purposes. According to the different heating temperature, it is generally divided into three types. The temperature above 1000 degrees is called high temperature box type resistance furnace, the temperature between 600 and 1000 degrees is called medium temperature box type resistance furnace, and the temperature below 600 degrees is called low temperature. Box type resistance furnace to meet the needs of irregular heat treatment temperature.
There are many types of pit-type resistance furnaces, and their uses are also relatively wide. They mainly work in natural atmosphere or protective atmosphere to heat treatment or sinter long metal workpieces (rods, long shafts).
Most of the pit-type resistance furnaces are cylindrical. Due to the long furnace body, in order to facilitate the operation of loading and unloading workpieces, large and medium-sized pit-type resistance furnaces are usually installed in the pit, only part of which is exposed on the ground, and the furnace shell is made of steel plates. , The lining structure is similar to that of the box-type resistance furnace, which is composed of an insulating refractory layer and an insulating layer. According to the different working temperature, it is divided into high temperature, medium and low temperature pit type resistance furnace, each using different lining materials. In order to reduce the volume of some pit-type resistance furnaces, the furnace body and furnace cover are all water-cooled. This kind of furnace has no refractory layer and thermal insulation layer, and uses metal materials as heat shields, and its energy consumption is higher than that of thermal insulation materials. The lining is much larger.