GB447114A - Improvements in or relating to rotating hearth furnaces - Google Patents

Abstract

447,114. Tunnel furnaces. McLAY, G. S., Shell Mex House, Strand, London. Oct. 12, 1934, No. 29234. [Class 51 (ii)] In an annular furnace, particularly for heating billets, the roof 8, side walls 1, 1<1>, and the rotary hearth 17 are all separately supported and means are provided for effecting, without moving the roof or the main body of the hearth, relative adjustment as to height between the lower edges of the side walls and the hearth. The walls 1, 1<1> are carried by ring structures bolted to vertical stanchions 2, 2<1> and each formed in two parts 3, 4, and 3<1>, 4<1> bolted together, the lower portions 6, 6<1> of the parts 4, 4<1> being watercooled and carrying sealing plates 13, 13<1> depending into sand troughs 44, 44<1>. The adjustment between the walls 1, 1<1> and the hearth may be obtained by providing slotted bolt holes in the stanchions 2, 2<1>, by placing packing pieces between the ring structures 3, 4 and 3<1>, 4<1>, or, as shown in Fig. 4, by making the outer sections 19, 19<1> of the hearth vertically adjustable on the main body thereof. This latter is effected by the provision, in the outer hearth-supporting rings 14<1>, 14<5>, of slotted holes through which are passed bolts securing these rings to the adjacent rings 14<2>, 14<4>. The outer rings 14<1>, 14<5> are formed with upstanding flanges 15, 16 which embrace the outer hearth sections 19, 19<1> and carry sealing plates 21, 21<1> depending into the troughs 44, 44<1>. The hearth-supporting rings 14' ... 14<5> are freely supported upon I-beams 23 to which are secured circular beams 24, 25 carrying the rails 27, 28, which run on rollers 29, 30, and a rack 32 co-operating with one or more driving pinions. Certain of the beams 23 are formed with projections 33, 33<1> which engage between spaced projections 34, 35 and 34<1>, 35<1> on the rings 14<1>, 14<5> with sufficient play to permit a limited movement of the hearth due to expansion and contraction.