What is the working principle of a box furnace?

The working principle of a box furnace is mainly based on the principle of resistance heating. The following is a detailed explanation of its working principle:

Resistance heating: The heating elements of a box furnace are usually resistance wires or resistance strips, which are installed around or at the bottom of the furnace. When current passes through these resistive elements, electrical energy is converted into thermal energy due to the effect of resistance. These heat will be transferred to the workpiece in the furnace, causing the workpiece to reach the required heating temperature.

Temperature control: Box furnaces are usually equipped with a temperature control system, which monitors the temperature inside the furnace through temperature sensors such as thermocouples and feeds back the temperature signal to the controller. The controller adjusts the current of the heating element based on the preset heating curve and current temperature signal, thereby controlling the temperature inside the furnace. This closed-loop control system can ensure that the temperature inside the furnace is stable within the set range.

Atmosphere control (some models): Although most box furnaces do not emphasize atmosphere control, some advanced models may be equipped with an atmosphere control system. These systems can control the atmosphere inside the furnace, for example, by introducing inert gas to prevent reactions such as oxidation or decarbonization of the workpiece during the heating process.
Heat conduction and convection: In a box furnace, the workpiece mainly absorbs heat from the furnace through heat conduction and convection. After the heating elements in the furnace generate heat, the heat will be transferred to the workpiece through the furnace wall. At the same time, the hot air inside the furnace will also transfer heat to the workpiece through convection, thereby accelerating the heating process of the workpiece.

In summary, the working principle of a box furnace is mainly based on the principle of resistance heating. By controlling the current of the heating element and the atmosphere in the furnace, precise heating and temperature control of the workpiece are achieved.