Quite often, in the process of various production, heating, hardening or other heat treatment of the part is required. In this case, it is necessary not only to observe a certain temperature regime, but also to control cooling. Muffle furnaces are best suited for these purposes.
They got their name thanks to a special device, which is a chamber made of heat-resistant materials, designed to protect the part from various influences. For example, it prevents the product from coming into contact with the heating element, protects against environmental influences and helps maintain temperature conditions.
There is a muffle furnace in which a device of this type is provided, where the muffle is installed permanently. It is quite practical and convenient, but after a certain period of operation it is subject to a complete re-equipment, or the camera is replaced. Therefore, in large industries, where such technological processes go on without stopping, a fundamentally different type of device is used that has a replaceable packing.
Such a muffle furnace works without interruption, and the parts are already immersed in it together with the muffle. Therefore, they require a certainamount. Given the short service life, such enterprises usually set up the production of muffles themselves.
The chambers of such furnaces are made from refractory materials of various properties. If a specific technological process requires rapid cooling, then thin-walled ceramics are used, but when it is required to keep heat in the furnace for a long time after it is turned off, then special mineral wool or other packing made of heat-conducting and refractory material is used.
There are many heating methods that the muffle furnace uses. It can run on gas, wood, diesel or other liquid fuels, but most often they use electric heating elements. They allow the furnace to be heated evenly (cooling also occurs), to exercise precise control over the temperature during operation. At the same time, special pyrometric devices can be connected to them, thanks to which the entire heating and cooling mode can be performed automatically. To control the temperature, thermocouples made of special alloys are usually used, which are located inside the device.
The simplest muffle furnace is made with a metal case, in which heating elements and control devices are installed. After that, its camera is made, which is installed inside. At home, refractory bricks and clay are used for this. They are the most affordable materials and have good technical characteristics.
Such a muffle furnace can last long enoughfor a long time, and replacing the camera itself will not be difficult and will not entail special material costs. It is worth noting that most industrial devices of this type have exactly the same assembly principle, although the material of the muffle can be changed for different conditions.
