Rotary tube furnaces are widely used in industry for the production of speciality powders and granulate. Their operating principle ensures that the powder bed is in constant motion and can therefore efficiently degas or react. In addition to the residence time of the powder in the furnace, the application temperature is a crucial process parameter. In this connection, metal rotary tubes are limited to around 1150℃. Moreover, there are certain powders that should not come into contact with metal. For such applications there is a need for ceramic rotary tube furnaces. This need can sometimes be met with rotary tubes consisting of a metal carrier tube with a ceramic lining. Such furnaces are then heated from the inside, e.g. by means of burners; these furnaces are referred to as directly heated rotary tube furnaces. In the following, an alternative approach is described. Here a ceramic tube is used, which is electrically heated from the outside, i.e. an indirectly heated rotary tube furnace.
展开▼
