GB488262A - Improved tunnel kiln for firing ceramic ware - Google Patents

Abstract

488,262. Tunnel kilns. GENERAL MOTORS CORPORATION. Jan. 1, 1937, No. 45. Convention date, Jan. 4, 1936. [Class 51 (ii)] In a, tunnel kiln for firing ceramic ware, and more particularly sparking - plug porcelains, the burners 60 are arranged to direct the flame on to the ware so as to produce surface combustion thereon and the tunnel in the firing-zone, and preferably also in the preheating- zone, is divided by a partition 52 into upper and lower flues, which are connected by ports 54 adjacent the burners to permit ready escape of gases from the lower to the upper flue. There are also connecting-ports in the preheating-zone and a large end port adjacent the stack flue, which leads from the upper tunnel at the entrance end of the kiln, The partition 52 carries no load but its own weight and serves to transmit heat and to radiate it on to the ware. The cooling-zone of the kiln comprises a solid masonry section C<1>, an airjacketed section C<2>, and a number of spaced sheet-metal chambers 72 where the ware is finally cooled by air blasts preferably directed towards the entrance end. The porcelains are carried in single file on wheeled cars 30 running on a vertically-adjustable track 16 which closes the slot between the base-plates 14 of the kiln. The parts of the base-plates nearest the slot are water-cooled, and the remaining parts are cooled by air which may be supplied by a fan to a heating-pipe 24 in the upper flue and so to the burners. If the kiln and the cars are designed to carry transverse rows of porcelains, additional burners are provided in the roof to direct their flames downwards on to the ware, and in the Specification as open to inspection under Sect. 91, a kiln of this kind is described with reference to a drawing, which does not appear in the Specification as accepted. Reference has been directed by the Comptroller to Specification 335,154, [Class 51 (ii)].