What is the difference between a box furnace and a vacuum furnace?

There are significant differences between box furnaces and vacuum furnaces in multiple aspects. The following is a detailed breakdown and summary of the differences between the two:

working principle:
Box furnace: When the workpiece is heated in a box resistance furnace, there is not only radiation heat transfer between the heat source and the surface of the workpiece, but also convection heat transfer. The box furnace is easy to operate and equipped with a controllable chimney behind the furnace, suitable for chemical analysis and heating treatment in various industries.
Vacuum furnace: A high-temperature electric furnace that uses a vacuum system to discharge some materials inside a specific space in the furnace chamber, so that the pressure inside the furnace chamber is less than a standard atmospheric pressure, achieving a vacuum state. Vacuum furnaces are commonly used to perform processes such as annealing, brazing, sintering, and heat treatment, and have the advantages of high viscosity and low pollution.

Structural features:
Box furnace: The furnace is box shaped with a simple structure. The furnace is made of stainless steel plates and enclosed in a heating and hot air circulation chamber. The furnace and furnace frame are designed for separation, making them easy to operate and maintain. The control system is integrated on the furnace body and controlled using an intelligent program temperature controller.
Vacuum furnace: The structure is relatively complex, including multiple parts such as vacuum system, heating system, temperature control system, etc. The vacuum system achieves a vacuum environment inside the furnace through mechanical pumps, maintenance pumps, and diffusion pumps. Heating systems are typically heated by resistance elements made of graphite, ceramics, or metals. The temperature control system can accurately control the temperature inside the furnace.

Application field:
Box furnace: widely used in the chemical analysis of coal, coking products, chemical raw materials, as well as industries and departments such as electricity, coal, papermaking, petrochemicals, cement, agriculture and animal husbandry, pharmaceutical research, teaching, etc.
Vacuum furnace: mainly used for ceramic firing, vacuum smelting, degassing of electric vacuum parts, annealing, brazing of metal parts, and ceramic metal sealing processes. Vacuum furnace can accurately control the chemical composition of alloys, remove low melting point volatile metal impurities, and improve material properties.

Performance characteristics:
Box furnace: easy to operate, easy to maintain, with high precision in temperature control and constant temperature, it can meet the needs of most industrial applications.
Vacuum furnace: Heat treatment under vacuum conditions can prevent reactions such as oxidation and decarburization, ensuring product quality. The vacuum furnace also has functions such as over temperature alarm, leakage protection, and overvoltage protection, ensuring safe and reliable operation.

In summary, there are significant differences between box furnaces and vacuum furnaces in terms of working principles, structural characteristics, application fields, and performance characteristics. When choosing which equipment to use, it is necessary to decide based on specific process requirements and production needs.