GB957185A - Improvements in or relating to baking ceramic or loose material - Google Patents

Abstract

957,185. Continuous kilns. J. W. LUDOWICI. Aug. 18, 1960 [Aug. 20, 1959], No. 28445/59. Heading F4B. A continuously operated kiln for firing ceramics or baking loose material comprises a raised stationary hearth 1 and a travelling tunnel 3 having preheating, firing and cooling zones 5, 4 and 6 respectively. The firing zone 4 has oil burners 7 supplied with preheated air, which also enters through ports 8, flue gases discharging through opening 9 into a duct 10 in the hearth communicating by radial ducts 18 with a central header 19. Cold air entering the cooling zone 6 through port 11 passes through port 12, hearth duct 13 and port 14 into the preheating zone 5, being extracted by a fan 16 in an outlet port 15. Circulation of the hot air may also be provided by ducts 23 feeding an annular collecting duct 22, control dampers 24 being provided. The hot air duct 13 may be disposed between a pair of waste gas ducts 10, Fig. 6, by which they are heated and lateral ducts may be provided for heating the combustion air, Fig. 3 (not shown). Dampers 21 control the inner ends of ducts 18 which may be extended outwardly to chimneys 25 controlled by dampers 26. The tunnel 3 runs on wheels 41, and, during movement, its roof may be raised by hydraulic cylinders 42. The hearth may be trough-shaped with linear or curved sides, Figs. 8-13 (not shown). When the kiln is used for treating loose material, the tunnel 3 is preceded and followed by attached casings preventing collapse of the material and formed respectively with upper charging and discharging openings, Figs. 14-16 (not shown). In a modification, Figs. 17 and 18 (not shown), the tunnel is supported by lateral caissons floating in channels in which the water or other liquid level may be varied. The kiln may be closed by sliding doors 106, Fig. 19, suspended by wheels 105 from a framework 100 carrying a pair of cantilevers 108 on each of which is hingedly mounted an hydraulic cylinder 116 and operating levers 111, 112 the latter being hingedly mounted at 113 to a door wing 106. An inflatable seal 107 is provided around the door opening, against which the doors with their associated framework 100 may be pressed.