The working gate is also made into frame by specially-made alumium profile, and folded to inner plate by alumium plate, ladder-shaped raised grain alumium plate made into panels. Filled glass wool in the space between inside and outside the plate to keep warm. There are sealing strips around the gate inside in order to heatproof and moisture proof. The cradle rail is made of steel. There are roll collars on two sides of the gate frame used to lock strictly, an inclined plate installed on the side of the kiln gate frame used to lock strictly, when the working gate is getting down, it could be lock automatically. The gate cradle is welded by square tubes in rail patten way.