The air in the kiln will be heated and in the same time saturated steam will be blown in the kiln. Slowly all air will be pressed out and will be replaced by saturated steam. During the heating phase, we try to maintain the relative humidity as close as possible to 100%. Pressure in the kiln will be vented to the outside through an overpressure valve.

Principle

At the moment, that we have reached a temperature of 100°C and 100% RH in the heart of the timber, we have a 100% saturated steam condition in the kiln. After this condition, the kiln is heated more (over 100°C) without adding any extra steam.

The saturated steam will than change into overheated steam, the water in the timber will start boiling. This again causes a slight overpressure in the timber and the water will be pressed out very fast and will condensate in the overheated steam. A little overpressure, which we will have in the kiln during this process, will be vented outside.

This system gives a very short drying time, without any damage to the timber because the kiln is completely closed, so no exchange with outside air gives a big energy saving.