FR2180221A6 - High capacity ceramics kiln - has floor moving on heat expansion compensating continuous lines of balls in parallel tracks - Google Patents

Abstract

Disadvantages of constructions hitherto used for moving floors and their supports to tunnel kilns for firing ceramics, e.g. high mass and high heat capacity with resultant slow rise to firing temps. of 1500 degrees C, high movement resistance, or uneconomical cost, are overcome by adapting known arrangement -so far only suited to low temps.- of supporting light moving floor flags on the stationary floor by uninterrupted lines of balls running freely in parallel grooves cut into opposite floor faces. Expansion of such lines of balls, which must always touch one another to form a continuous moving line throughout the kiln, is compensated by withdrawing appropriate number of heat expansion created "surplus" balls, either automatically by providing escape/temporary storage spaces in the moving floor, and/or through escape hatches to the stationary floor for one ball at a time, controlled by the press. of the expanding ball line or by programmed mechanism- so removing "surplus" balls until re-circualted after cooling, pref. automatically via pneumatic tube type arrangement. Ball lines are secured against cross movement by distance plates almost filing the spaces between the balls in their grooves and between balls and the floor edges. Kiln may be inclined in the direction of travel to effect floor movement under gravity. Floor materials may be Al-Mg-silicates, which may contain CaO and Fe2O3, e.g. Cordierite (RTM), ball materials sintered metal oxides, e.g. alumina.