Patent GB-593444-A (GB)
Title: Improvements in method and apparatus for attempering materials
IPC: F26B17/28
Filed: 1945-05-15
Abstract: 593,444. Drying, cooling &c. granular &c. materials. BAKER, D. S. May 15, 1945, No. 12208. [Classes 34 (ii) and 64 (ii)] Apparatus for drying, cooling or otherwise attempering granular, plastic &c. materials comprises essentially an attempering drum 10 rotatable by a part-surrounding endless belt 13, the drum and belt defining a thin extended chamber C and a longitudinal hopper H having a material charging chute 20 at one end and a port 18b leading to a discharging screw conveyor S at the other end. Preferably the belt 13 comprises two marginal link chains 38 which are connected by transverse overlapping thin plates 40 extending over radially projecting end flanges 17 on the drum 10, and it may be supported by rollers 14, 15, 16, the roller 14 being rotated through its shaft 14a. A downwardly inclined longitudinal doctor blade 37 in contact with the drum 10 is provided above the hopper H, as shown, and at the level of the hopper there is fitted an angle member 24 having spaced fingers 22 in alignment with apertures 21 in the horizontally-slidable front wall 18 of said hopper, the member 24 being mounted on cams 25 which are rotated from the shaft 14a through pulleys 30, 32 and worm and worm wheel 36 to cause said member 24 to move in succession towards the drum 10, the fingers 22 taking up the position shown in dotted lines, Fig. 1, then towards the right-hand end of the apparatus, next, rearwardly away from the drum and, finally, to its original left-hand position. The apparatus is preferably enclosed by a casing 43 provided with a transverse partition 45a and side exhaust ports 44 locating fans 45. The arrangement is such that material fed continuously to the chute 20 and hopper H will be applied to that part of the drum spanned by the chute and will be carried round by the drum to the doctor blade 37 when it is removed from the drum and permitted to fall back into its original position in the hopper. This operation is continued until the material builds up to the height of the fingers 22, when actuation of the member 24 carrying the latter will cause the material above the fingers to move to the right to contact and rotate with another part of the drum, repeated actuation of the member 24 effecting final discharge of the material to the conveyor S. If desired the drum may be attempered, e.g., by the introduction of a medium through a space 11a around the shaft 11 thereof. In a modification, the belt 13 is of standard mesh screen construction and extends almost wholly around the drum, and the latter is preferably perforated so that an attempering gas may be circulated through both the belt and the drum and also the material therebetween. Further, the material removed by the doctor blade falls on to a conveyer which leads to the throat of the hopper and has deflector plates, instead of fingers 22, associated with its upper surface and inclined to the right-hand side of the drum. A drum having a plurality of portions of progressively increasing diameter separated by radial flanges which form, with the partencircling belt, chambers of different depth may also be employed, the material being fed to the chamber of least depth and being advanced laterally of the drum through the other chambers in succession.