Ceramic Kilns

Industries kilns are huge ovens, which carry the work of thermal processing at very high temperatures mostly above 2500°F. They are used on a wide scale to make ceramic materials and for drying wood and wood products. They are also used to break down waste materials like paper pulp and used tires.

There are a variety of industrial kilns:

1 Brick Kilns
2 Electric Kilns
3 Rotary Kilns
4 Ceramic Kilns

These kilns are of two basic types i.e. Continuous and Intermittent.
A continuous kiln is also known as a tunnel because of the long tunnel like shape. In a continuous kiln there is a cool end from where the material is inserted and only the central portion is heated. As the material moves (on rollers or other types of conveyers) from the insertion point, the temperature gradually increases till it reaches the center, which is the hottest part of the kiln. Then the material is carried towards the exit, where it returns back to room temperature.
An intermittent kiln is one in which the firing process starts once the material is inserted into it and the kiln is sealed. The temperature of the kiln is steadily increased to the required temperature. The kiln and the material are cooled after the firing process is completed.

Ceramic is a refractory material used in kilns. The crucibles and linings used in kilns are made of this ceramic refractory. Ceramic refractors have highly specialized characteristics. Refractors are insulators that can resist heat of high temperatures. This material prevents fusion, softening, the action of fluxes and slag, controls temperatures, etc. These are heavy insulators that provide solutions to challenges of thermal management. These are used in kilns as they utilize heat and encounter high temperature. They are powered by gas, propane or electricity. Most of the modern day kilns use electricity and natural gas. Most of the large pottery industries are using natural gas now days as it is efficient, easy to use and is clean too.

There are various types of ceramics insulations used in kilns like:

1 Ceramic fiber insulations
2 Ceramic textiles
3 Ceramic kiln furniture

These insulators mostly consist of fibers like cloth, rope, batting, paper and many other such products. Braiding, extrusion, knitting and weaving are different ways ceramic fibers are made. There are layers of such materials in the kilns known as blankets. These blankets are of two types:

Woven: These are used to form multi-dimensional structures and composite tooling.

Non-woven: These materials are in the form of mats made of randomly selected insulating fibers.

Features of ceramic kilns:

1 Provides high resistance to abrasion, chemical erosion
2 High resistance to thermal shock
3 Low thermal conductivity
4 Highly resistant to pressure and provides structural integrity

Potters and glassmakers use ceramic kilns on a wide scale. They are also used to make moulds, tools, glazes, etc.