GB639666A - Improvements in or relating to rotary furnaces - Google Patents

Abstract

639,666. Rotary-hearth furnaces. KEENER, S. F., (trading as SALEM ENGINEERING CO.). July 2, 1947, No. 17493. Convention date, June 7, 1941. [Class 51 (ii)] In a furnace comprising concentric inner and outer side walls spanned by an annular roof, an annular refractory hearth located between the side walls and mounted on a rotatable framework, and annular sand seals spanning clearances between the edges of the hearth and the side walls, the hearth seats on an annular plate which merely rests on the framework, and the latter is located wholly below the side walls and positioned relatively thereto by a system of abutting and radially-adjustable rollers, the troughs of the sand seals being carried on the framework also below wall level and being arranged to receive annular flanges depending from the walls and the crown of the framework. As shown, the furnace structure comprises a roof 12 keyed to inner and outer circular walls 10, 11 which are supported by circular plates 171, 18 and a plurality of columns 19, 20 from beams 17 interconnecting the lower ends of a plurality of circumferentially-disposed buck-stays 14 and 15, the upper ends of the stays being interconnected by tie members 16. The walls 10, 11 are formed with annular shoulders which overlie the edges of an annular hearth 13, 25 supported by a plate 26 which rests on I-section annular beams 33 and channels 34 secured to a framework comprising a plate 32, annular beams 31, channels 30 and radial members 29, the beams 31 carrying journal blocks 35 for rollers 36 running on rails 37. The hearth is thus free to expand and contract without affecting the supporting structure. The plate 26 carries a number of projections 74 which co-operate with the adjacent beam 33 to prevent excessive movement of the hearth. The outer channel 34 supports a flange 47 which dips into a sand trough 42 constructed in sections 43 each detachably mounted by means of brackets 44 on the outer channel 30, the columns 20 supporting a flange 49 which also dips into the trough. A similar sealing arrangement is provided at the inner edge of the hearth. A continuous channel 40 is secured to the inner ends of the members 29 and is engaged by a number of adjustable guide rollers 51 mounted on the columns 19. The outer ends of the members 29 support a channel 41 -secured to which is a channel 58 having a plurality of movable pins 59 extending through its flanges 60. Each pin is encircled by a wear sleeve 61 and forms a tooth for engagement with a driving sprocket 62. The walls 10, 11 are formed with flues 22 and burner ports 21, and the furnace chamber is divided into seven zones by baffle walls 65 and 70 extending downwardly from the roof. These walls are constructed of arches 66, keyed into the side walls, and a lower section formed by refractory brickwork 68 which is filled in between water tubes 67 and the lowermost arch. The wall 70 extends closer to the hearth than the other walls and is disposed between the charging inlet 71 and discharge outlet 72.