| 摘要 |
Directly fired tunnel kiln heated with solid fuel stand using one or more tunnels arranged side by side. Both side walls inside each tunnel have a zig-zag shaped aligned w.r.t. each side so the free cross-section between the charge and the tunnel wall is constant; and firing grates are located in the recesses formed by the zig-zag walls. Channels in the roof are pref. used to feed fuel into the recesses; and similar channels are pref. provided in the hearth to remove ash. The stacks of workpieces are pref. located at a slight angle w.r.t. the transverse direction of the tunnel to facilitate the circulation of the heating gases. The direction of the heating gases flowing through the tunnel may be periodically reversed for short periods. The kiln can be fired with wool or coal without forming ash on the workpiece or the kiln-cars carrying the workpieces. Good heat transfer is achieved to continuously moving kiln-cars even using wide tunnels. |
