DK200000039A - Apparatus for agglomerating powder, specifically coffee, has rotating drum against which powder, with steam and water, is projected through atomising nozzle; agglomerated powder is dried in fluid bed; fines are recirculated - Google Patents

Abstract

Process for agglomeration of powder by bringing the powder into contact with an agglomeration fluid while being directed towards a moving surface onto which the powder is collected and subsequently discharged by centrifugal force, while optionally being dried; all parts of the moving surface are moving at the same speed; the centrifugal acceleration of the powder is at least 50m/s2. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for an apparatus (1) with moving surface (4) for collecting powder (5); means (3) for applying agglomeration fluids (8,9); means (13,16) for drying agglomerated powder. Preferred Features: - The centrifugal acceleration is (a) 50 to 5000m/s2; (b) 100 to 2500m/s2; 200 to 1250m/s2. The speed of the moving surface is (a) 2.5m/s; (b) 3.5m/s; (c) 5.0m/s. The moving surface is impervious to fluids. The moving surface is a rotating drum or cylinder. The diameter of the drum is 0.25 to 1.5m, preferably 0.35 to 1.0m. The drum rotates at 80 to 2000rpm, preferably 100 to 1000rpm. The agglomerated powder is classified; fines are recirculated. The powder is coffee or coffee substitute. Tube (10) and atomising nozzle (11) introduce agglomeration fluids and optionally atomising gas centrally in annular opening of tube (7) through which powder is introduced. The atomising nozzle is a two fluid nozzle for atomisation of liquid with gas. The atomising nozzle extends beyond annular opening. The nozzle discharges at 0.1 to 1.0m from drum surface. The distance between nozzle and drum is adjustable. Speed of drum is adjustable. Agglomerated powder is post-dried and cooled in fluid bed (16) with conveyor belt (17).

Description

PATENT CLAIMS 1. A process for agglomeration of powders, wherein the powder to be agglomerated is brought into contact with an agglomeration fluid while being directed towards a moving surface onto which the powder being agglomerated is collected and the powder being agglomerated subsequently moved away from the moving surface by influence of centrifugal force and optionally dried, characterized in that all parts of the moving surface are moving at substantially the same speed and that the agglomerated powder is moved away from the moving surface by means of a centrifugal acceleration of at least 50 m / s2. A process according to claim 1, characterized in that the centrifugal acceleration is in the range from 50 - 5000 m / s2, particularly in the range from 100 - 2500 m / s2, and more particularly in the range from 200 - 1250 m / s2. A process according to claim 1 or 2, characterized in that the moving surface is moving at a speed of at least 2.5 m / s, particularly at a speed of at least 3.5 m / s and more particularly at a speed of at least 5.0 m / s. A process according to any of claims 1-3, characterized in that the moving surface is substantially impervious to fluids. A process according to any of claims 1-4, characterized in that the moving surface is the curved surface of a cylinder or drum rotating about its central axis. A process according to claim 5, characterized in that the cylinder or drum has a diameter in the range from 0.25 m - 1.50 m, particularly in the range from 0.35 m - 1.00 m. 7. A process according to claim 5 or 6 , characterized in that the cylinder or drum is rotating at a speed in the range from 80 - 2000 rpm, particularly at a speed in the range from 100 - 1000 rpm. A process according to any of claims 1-7, characterized in that the agglomerated powder is classified and fines recirculated for further agglomeration. 9. A process according to any of claims 1-8, characterized in that the powder is coffee and / or coffee substitute powder. 10. An apparatus (1) for agglomeration of powders, said apparatus comprising a movable surface (4) for collection of the powder (5) being agglomerated, means (3) for bringing the powder to be agglomerated into contact with one or more agglomeration fluids (8, 9) while being directed towards the movable surface (4), means for moving the movable surface and optionally means (13, 16) for drying the agglomerated powder, .the movable surface (4) having such configuration that the collected powder (5) being agglomerated is moved away from the moving surface by influence of centrifugal force when the apparatus is in operation, characterized in that the movable surface (4) has such configuration that all parts thereof are moving at substantially the same speed when the apparatus is in operation, and that the apparatus is adapted to provide the collected powder (5) being agglomerated with a centrifugal acceleration of at least 50 m / s2 so as to move it away from the moving surface. 11. An apparatus according to claim 10, cha racterized in that it is adapted to provide the collected powder (5) being agglomerated with a centrifugal acceleration in the range from 50 - 5000 m / s2, particularly in the range from 100 - 2500 m / s2, and more particularly in the range from 200 - 1250 m / s2. 12. An apparatus according to claim 10 or 11, characterized in that the means for moving the movable surface (4) is adapted to move the movable surface at a speed of at least 2.5 m / s, particularly at a speed of at least 3.5 m / s and more particularly at a speed of at least 5.0 m / s. 13. An apparatus according to any of claims 10 - 12, characterized in that the movable surface (4) is substantially impervious to fluids. 14. An apparatus according to any of claims 10 - 13, characterized in that the movable surface (4) is the curved surface of a cylinder or drum (2). 15. A process according to claim 14, charac -terized in that the cylinder or drum (2) has a diameter in the range from 0.25 m - 1.50 m, particularly in the range from 0.35 m - 1.00 m. 16. An apparatus according to claim 14 or 15, characterized in that it comprises means for rotating the cylinder or drum (2) at a speed in the range from 80 - 2000 rpm, particularly at a speed in the range from 100 - 1000 rpm. 17. An apparatus according to any of claims 10 -16, characterized in that the means (3) for bringing the powder to be agglomerated into contact with one or more agglomeration fluids (8, 9) while being directed towards the movable surface (4 ), comprises one or more tubings (7) having a substantially annular opening for introduction of the powder (5) to be agglomerated and a tubing (10) positioned centrally within each annular opening for introduction of the agglomeration fluid (s) and optionally an atomizing gas, the centrally positioned tubing (10) ending in an atomizing nozzle (11) at the level of the mouth of the annular opening. An apparatus according to claim 17, characterized in that the atomizing nozzle (11) is a two fluid nozzle for atomizing a liquid with a gas. 19. An apparatus according to claim 17 or 18, characterized in that the atomizing nozzle (11) protrudes a small distance from the mouth of the annular opening. 20. An apparatus according to any of claims 10 -19, characterized in that the means (3) for bringing the powder to be agglomerated into contact with one or more agglomeration fluids while being directed towards the movable surface, debouches at a distance of 0.10 rn - 1.00 m from the movable surface (4). 21. An apparatus according to any of claims 10 - 20, characterized in that the distance between the movable surface (4) and the mouth of the means (3) for bringing the powder to be agglomerated into ^ contact with one or more agglomeration fluids while being directed towards the movable surface, is adjustable. 22. An apparatus according to any of claims 10 - 21, characterized in that the speed of the movable surface (4) is adjustable. 23. An apparatus according to any of claims 10 - 22, characterized in further comprising a fluid bed (16) for post-drying and cooling of the agglomerated powder. 24. An apparatus according to any of claims 10 -22, characterized in further comprising a conveyer belt (17) for post-drying and cooling of.the agglomerated powder.