GB1455234A - Method and apparatus for agglomerating finely divided agglomerative materials in a rotating drum - Google Patents

Abstract

1455234 Mixing apparatus DRAVO CORP 23 April 1975 [3 May 1974] 16873/75 Heading B1C A method of agglomerating finely divided agglomerative material, such as finely divided coal particles and finely divided particles of carbonaceous residue, comprises feeding the agglomerative material into a substantially horizontal rotating drum 12 having an inner wall 76, depositing a layer 126 of the material in the inner wall, rotating a .scraper 74 in the drum in a direction opposite to the direction of rotation of the drum to form a plurality of elongated alternating and longitudinally extending ridges and valleys in the layer, and mantaining the same ridges and valleys in the layer while rotating the drum and forming agglomerates from other finely divided agglomerative material into the drum. In apparatus for carrying out the method, a drum assembly 10 comprises a balling drum 12 and a hardening drum 14. The drum 12 has an inlet opening 16 in a stationary housing 36 and a discharge opening 18 which is in a stationary housing 20 and comimunicates with the inlet opening 20 of the hardening drum 14, a discharge opening 24 of the drum 14 extending into a housing 26 having a trummel screen 24 and outlets 30, 32. The drum 16 has tyres 48, 50 engaging roller assemblies 52, 54, and a gear 42 meshing with a gear 44 driven by a drive means 46: the drum 14 is supported and rotated in a similar manner. The assemblies 52, 54 and housing 36, which has inlets 38, 40 for feeding the material to the drum 12, are carried by a platform 58 vertically adjustable to vary the inclination of the drum. The scraper 74 has a body portion 80 and shaft portions 82, 84 mounted in bearings 88, 96 carried by channels 92, 98 in the housing 36, 20, the bearings being positioned so that the axis of the scrapers is disposed above and to one side of the axis 15 of the drive 12. The scraper is rotated by a belt drive from a motor 100 in the opposite direction to, and in timed relationship with, the rotation of the drum. The scraper, (as described), has two rows of radially adjustable blades 108, 110 which are arranged to follow helical paths 124 of less than one turn, but may have one, three or four rows arranged parallel to the axis of the scraper. In use, agglomerative material, such as particulate bituminous coal and finely divided char and pitch, the coal being at 400‹F to 625‹F and the char at 1000‹F to 1200‹F, is introduced into the drum 12 and are mixed so the drum is rotated and form a layer of a sticky plastic mass on the inner surface of the drum. As the scraper rotates it forms the ridges 130, 132, 134, 136 and valleys 138, 140, 142, 144 in the layer which hardens. Further agglomerative material introduced into the drum forms a bed 146 of material which is agitated so the ridges and valleys move under the bed and effects top to bottom mixing and turning. The agglomerates 152 grow until the binder loses its plasticity and then pass to the hardening drum. The ridges may be supported by metallic members secured to the drum. For Figures see next page