Quite often, in the process of various production it is required to produce heating, hardening, or other heat treatment of the part. In this case, it is necessary not only to observe a certain temperature regime, but also to control the cooling. For these purposes, muffle furnaces are best suited.
They got their name thanks to a special device, which is a camera made of heat-resistant materials, designed to protect the part from various influences. For example, it prevents the product from contacting the heating element, protects against environmental influences and helps maintain the temperature regime.
There is a muffle furnace in which a device of this type is provided where the muffle is installed stationary. It is quite practical and convenient, but after a certain period of operation it is subject to complete conversion, or the camera is being replaced. Therefore, in large plants, where such technological processes go on non-stop, a fundamentally different type of devices are used that have interchangeable packing.
Such a muffle furnace works without interruption, and the details are immersed in it already with the muffle. Therefore, they require a certain amount. Given the short service life, such enterprises usually organize the production of muffles themselves.
They make chambers of such furnaces from refractory materials of various properties. If a particular technological process requires rapid cooling, then thin-walled ceramics are used, and 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 a muffle furnace uses. It can work on gas, wood, diesel fuel 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 from special alloys that are inside the device are usually used.
The simplest muffle furnace is made with a metal case in which heating elements and control devices are installed. After which her 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 enough, and replacing the chamber 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 muffle material can be changed for different conditions.