GB478843A - Improvements relating to apparatus for subjecting materials to drying or cooling treatments - Google Patents

Abstract

478,843. Endless-chain elevators. BUELL [COMBUSTION CO., Ltd. (Buttner- Werke Akt.-Ges.) Oct. 23, 1936, No. 28903. [Class 78 (i)] [Also in Group XIII] Apparatus for drying or cooling materials comprises one or more rotary cages mounted to rotate vertically inside a chamber, an endless belt for carrying the material being located partly outside the chamber but having most of the length inside the chamber in the form of a vertically-disposed helical belt column of small' pitch which is driven by engagement with members carried by the cage or cages, means being provided for keeping the superposed turns of the belt column continually spaced apart in the vertical direction, and one or more fans being provided inside the cage or cages to force air outwardly across the material on the belt. In the construction shown in Figs. 1 and 2, material to be dried is conveyed into a drying chamber 1 on an endless belt 2 arranged in the form of a helix of small pitch. The belt is made up of trays 10 with sector-shaped spaces 11 between. The outer edges of the belt are fitted with rollers 3 which run on rails 4 fixed to the inside of an openwork frame 5. The inner edges of the belt have rollers 6 resting on spaced supports 7 carried by endless chains 8 which are carried by a rotary cage 8a. As the cage rotates, the belt is driven by its engagement with the supports 7 on the chains 8. The chains effect the lowering of the turns of the belt as it travels through the chamber 1. Drying is effected by means of fans 9 driven from a vertical shaft 9a which also drives the endless chains 8. The fans circulate air across the material on the belt and past heating elements (not shown) which are provided in the annular space between the chamber 1 and the frame 5. In a modification, the endless chains 8 are replaced by helical surfaces on vertically-disposed spindles driven from the fan shaft. In a further construction shown in Figs. 5, 7 and 10, the fans 9 are enclosed within a rotary cage 15 fitted with vertical rods 16. An endless chain composed of links 17, is wound helically around the framework of rods 16, the chain entering the drying chamber 1 at the top. The end of each link 17 is fixed to a member 17a loosely mounted on a bolt 22, and the inner edges of the members 17a, are recessed to engage the rods 16. Each belt section consisting of a wire mesh tray 18 is secured at its inner edge to a link of the chain. The outer edge of each tray is fitted with two rollers running on fixed helicallyarranged rails 20 carried on the inside of a cylinder 21. The connecting bolts 22 for the chain links bear on one another inside the chamber 1. The weight of the belt column is taken partly by the rails 20, but mostly by rollers 24 which are mounted on trolleys 25 free to slide vertically on the rods 16. Where the lowermost tray 18 leaves the chamber 1, the associated roller 24 is relieved of the weight by means of a cam-operated lever 32 carried by the cage 15 through the medium of a bar 28 with limited sliding movement. The bar is supported on a roller 30. The rollers 24, 30 run in tracks 26, 31, arranged in co-operation with cam rails 35, 37, so that at the place of discharge from the chamber, the lever 32 engages the bolt 22 above the lowermost bolt, permitting free discharge of the lowermost tray section 18, the lever 32 subsequently being moved clear of the bolt as shown at the righthand side of Fig. 7. In a further construction shown in Fig. 11, a chain 37 having transverse supporting bars 38 is arranged in the form of an elongated helix inside a drying chamber 39 which is provided with two rotary cages 40 containing fans. The material to be dried is spread out in a continuous belt 42 placed on the bars 38 to form shallow festoons between the bars. The outer periphery of the chain 37 is supported on guide rails 41 in the form of an elongated helix. The chain is driven by projections on the cages 40.