Box type resistance furnace can meet the requirements of various heat treatment processes and is widely used in heat treatment workshop. Small enterprises and township enterprises have fully realized the importance of heat treatment of workpieces. Many heat treatment enterprises (workshops) emerge as the times require. Box type furnace has become the most popular heat treatment equipment, generally medium temperature box type resistance furnace.
However, due to the low level of operation technology of workers, when charging and discharging, the workpiece often collides with the furnace back wall and the furnace walls on both sides, resulting in the furnace wall damage, reducing the thermal efficiency of the box resistance furnace, increasing the heat loss, and even causing the furnace wall collapse. In manual operation, if the hook is not very good, it will easily collide with the electric furnace wire, causing damage to the electric furnace wire. If the protection switch is damaged (some enterprises even do not have a protection switch), it is easy for the operator to get electric shock.
1. Improvement measures
In order to meet the use requirements of production status and extend the service life of box resistance furnace, the following measures are proposed mainly from improving the lining structure
(1) The furnace back wall is replaced by heavy refractory brick. According to the current design requirements of rx2 series box type resistance furnace, the back wall of the furnace generally adopts light refractory clay brick or floating bead brick with low thermal conductivity, but because of its low strength, it is easy to damage the back wall of the furnace due to bumping when the workpiece is loaded into the furnace.
Therefore, heavy refractory clay brick with high strength is used for masonry. In order to ensure the thermal efficiency of the box resistance furnace, the specific measures are as follows: the back wall of the furnace is divided into two parts, the upper part is built with several layers of heavy refractory clay bricks (the specific number of layers depends on the size of the furnace and the use requirements), and the upper part is still built with light refractory clay bricks.
(2) 1-3 layers of heavy refractory clay bricks (depending on the size of workpieces) are used at the bottom of furnace walls on both sides to prevent damage of furnace lining due to improper loading and unloading of workpieces.
(3) A layer of aluminosilicate refractory fiber with low thermal conductivity is added outside the refractory brick to improve the thermal insulation performance of the furnace lining.
2. Effect of improved lining
(1) After the improvement of the lining structure, the service life of the box resistance furnace lining is extended from one year to nearly two years under the same service conditions as before.
(2) The electric shock accident of operators is prevented.