Definition - What does Muffle Furnace mean?
A muffle furnace is a furnace with an externally heated chamber, the walls of which radiantly heat the contents of the chamber, so that the material being heated has no contact with the flame.
Muffle furnaces are most often utilized in laboratories as a compact means of creating extremely high-temperature atmospheres. They are employed to test the characteristics of materials at extremely high and accurate temperatures.
A muffle furnace is also known as a retort furnace.
Corrosionpedia explains Muffle Furnace
A muffle furnace is a piece of oven-type equipment that can reach high temperatures. It usually works by putting a high-temperature heating coil in an insulated material. The insulating material effectively acts as a muffle, preventing heat from escaping.
It is used for high-temperature applications such as:
- Fusing glass
- Creating enamel coatings
They are also used in many research facilities, for example by chemists in order to determine what proportion of a sample is non-combustible and non-volatile. Advances in materials for heating elements facilitate more sophisticated metallurgical applications.
The term muffle furnace may also refer to another type of oven constructed on many of the same principles as the one mentioned above, but takes the form of a long, wide and thin hollow tube used in roll-to-roll manufacturing processes.
Both of the above-mentioned furnaces are usually heated to desired temperatures by:
- Blackbody radiation from electrical-resistance heating elements
There is usually no combustion involved in the temperature control of the system, which allows for much greater control of temperature uniformity and assures isolation of the material being heated from the byproducts of fuel combustion.