GB1397004A - Apparatus for manufacturing ceramically bonded shaped bodies from granulates of expandable mineral material - Google Patents

Abstract

1397004 Treating materials with gases ZYTAN THERMOCHEMISCHE VERFAHRENSTECHNIK GmbH & CO KG 23 Jan 1973 3441/73 Headings F4B and F4K Apparatus for expanding materials particularly clay comprises a furnace 1 divided into two chambers 7, 8, and a firebox 13 containing the material to be treated supported in grooves 12 in the walls of the furnace. A burner 21 is arranged in a chamber 19 and its combustion gases together with gases entering conduit 23 pass down into the furnace, through the firebox 13 and out through a conduit 24. The exhaust gases pass through a reversing device 25 to a thermal regenerator 2 which has a heat retaining mass 50 flowing through it. The gases from the furnace are passed into the regenerator through conduit 27, give up their heat to the upper part of the mass 50 in chamber 31 and pass out through outlet 43. The gas passes through a cooler 42, a separator 72, a blower 41 and inlet 38 to lower chamber 32 of the regenerator. This gas is heated by the lower part of the mass 50 in chamber 32 and the hot gas passes out of the regenerator through the reversing device 25 and back to the furnace via conduit 23. The upper and lower chambers 31, 32 are separated by a throat 33 which allows the mass 50 to circulate from the upper to the lower chamber but prevents gas transfer between the two chambers. The mass 50 is circulated by an elevator which receives it via a bottom air lock 34 and returns it via an upper air lock 35. A burner 22 is provided in a chamber 20 which together with the reversing device enable the flow of gases through the furnace to be reversed. The form box consists of a frame 60, Fig. 2, of cast steel with spheroidal graphite. The upper and lower surfaces 62, 61 are received in the grooves 12 of the furnace wall so as to engage cooled surfaces. Alternatively, the frame can have its own cooler 74. The frame 60 is insulated from the fired material 69 by heat shields 63 held on narrow arms 64. The space between the heat shields and the frame is filled with insulating material, e.g. aluminium silicate fibre. In another form the heat-shield consists of two layers of different material, e.g. silicon carbide or boride and cobalt steel.