Patent GB-1189625-A (GB)
Title: Agglomeration.
IPC: B01J2/16
Filed: 1968-03-06
Abstract: 1,189,625. Agglomerating. PILLSBURY CO. 6 March, 1968 [7 March, 1967], No. 10811/68. Heading A2E. [Also in Divisions B5 and C3] Particulate materials e.g. foodstuffs, chemicals and minerals, are agglomerated by forming a bed thereof on a foraminous support through which is upwardly forced an agglomerating gas to fluidize the bed and to render the material surfaces adherent so that the material agglomerates into a mat like structure, and then rigidifying the agglomerates e.g. by the similar passage of a further gas, to form a cellular product which may then be broken up. Examples are given of the agglomeration of spray dried lactose gelatin, and carboxymethylcellulose. The agglomerating gas is usually sufficiently heated and/or contains sufficient water or other condensible liquid to render the surfaces plastic and the rigidifying gas may act by drying, cooling, freezing or a combination thereof. In one form of apparatus, the foraminous support comprises a driven, and adjustably tensioned, endless woven stainless steel screen 30 on to one end of which is fed pulverulent material from a variable gate hopper 100. The belt 30 passes over a gas supply plenum 80, comprising a series of compartments supplied from a valved gas distributing manifold and piping system, whereby the supply and the nature thereof to each compartment is controllable. Heated agglomerating gas which may be steam, or gas containing steam or moisture, is admitted to the compartment defined by walls 86, 94, and heated rigidifying gas is admitted to the remaining compartments. Adjustably tensioned rubber belt side guides are provided at either side of, and driven at the same speed, as the screen 30 over the initial region of the belt wherein the material is deformable. Edge guides, which may be stationary, or fastened to the screen if the endless belt side guides are omitted, are provided over the remainder of the screen run. A head is provided for collecting condensed gas. Additional rigidification and release of the material from the belt is effected by unheated or refrigerated air introduced through a blower 123, and the pieces 125 into which the discharged material breaks may be comminuted in apparatus 127, 129. The belt is cleaned by a water tank 132 whereafter it may be sprayed with water, fungicide or antibiotic, from a head 134 and dried by suction from a man 138 prior to heating by lamps 140. A plurality of moulding grids (230), Fig. 5 (not shown), each comprising interconnected vertical plates (232, 234), may be placed on belt 30 to mould triangular, rectangular, hexagonal, or other shapes corresponding e.g. to meat cuts, and the grids (230) may be covered with woven metal screen. In another embodiment, Fig. 4 (not shown), the foraminous support comprises successive endless belts (200, 206) respectively driven at faster and slower speeds, and on the former whereof the material is similarly agglomerated and breaks into pieces on delivery from the end thereof on to the second belt, whereon a thicker agglomerated layer is formed and similarly dried by a gas. The agglomerated layer can have applied thereto e.g. by spraying or doctoring, or by forcing upwardly therethrough on the second belt, fragrances, colouring, taste modifying substances, or a surface layer of icing. Ammonia treatment, oxidation cryogenic treatment, solvent extraction or treatment with alcohols, esters, ethers, oils and shortenings may be applied to the formed mat. Non- solution chemical reactions can be carried out e.g. 2NH 3 +6I=2NI 3 +3H 2 ; C12 H 22  On + H 2 O # C 12  H 22  On. H 20 . The invention may also be applied to converting a slurry to a porous mat by the use of a heated drying gas.