Infra-red radiation is also utilized for drying of ceramic articles. The infra-red radiation is largely reflected or transmitted by ceramic materials, where as water adsorbs it and converts it into sensible heat. Special lamps with comparatively low filament temperature radiate 80% of their energy in the infra-red.
This type of drying is suitable for green ware […]

In the first stage, the ware is warmed from 20oc to 45oc and the relative humidity of the air is maintained at 85%. In the second stage the relative humidity is lowered from 85 to 75%. In the third stage it is reduced to the maximum extent possible and at the same time the temperature […]

The new drying system has brought in the most advanced state-of-art dryers across the world and the newer version dryers are named as rapid dryers, where-in the articles can be dried within 3 to 4 hours. Conditions similar to these types of dryers can be produced in normal closed drying chambers indirectly heated with […]

As drying and shrinkage of the piece proceeds, the relative humidity can be reduced gradually at constant high temperature until the articles are completely dry. This is otherwise called humidity drying.
The success of the system is astonishing and the drying time has come down many folds for all ceramic articles whether it is brick, refractory, […]

Attempts to speed up drying by warming the air supplied sometimes lead to trouble because the capacity of the air for moisture is increased too much and water is removed from the piece too rapidly. The relatively high viscosity of water limits the rate of flow through the capillaries below surface. Faster capillary flow is, […]

For the uniform drying free from cracks, drying was effected by warm air rising from the ovens into the upper rooms of the factory or even by natural movement of the air in the open. Bricks were dried usually about 8 to 14 days, larger articles were dried for many months and sensitive glass parts […]

The progress of drying can be followed in various ways. The drying process can be seen very clearly in the volume changes. Since drying can proceed only at surfaces in contact with unsaturated air, it takes place most rapidly at places where the air is constantly renewed. In the storage location for articles standing […]

If the water vapour content of the air exceeds the maximum possible value of the absolute humidity at a given temperature, water will separate out in liquid form. This temperature is known as the dew point. For drying it is just as necessary for the air to be warm as to be dry. The amount […]

Air like all other gases has a certain capacity for taking up water vapour and this increases with rising temperature. At 100oC the amount of water vapour present in the space above freely evaporating liquid water is 100 per cent by volume, at 0oC it is practically nil. If the water content of the air […]

The presence of entrapped air in the clay articles hinders the drying operation by disrupting the capillary streams and cutting of the water remote from the surface. During drying the trapped air tends to expand on heating to a much greater extend than the clay and the pressure produced may break the piece. Hence the […]