GB1166056A - A Process and Apparatus for the Continuous Production of Voluminous Powder Agglomerates - Google Patents

Abstract

1,166,056. Agglomerating powders. O. PFRENGLE. 16 Nov., 1966 [26 Nov., 1965], No. 51382/66. Heading B5A. Voluminous power agglomerates, e.g. domestic detergents are continuously produced from a powder feed, e.g. from a powder blending feed extruded at a, into one end of a cylindrical, or frusto conical, drum which has a ratio of axial length to diameter, or mean diameter, of between 3 : 1 and 1À1 : 1, which is rotated at 6 to 60 r.p.m. and is provided with spray jets c, d in the inlet end of the drum and inclined downwardly toward the lower generatrix of the drum; the drum is filled by the powder to 25% or less of the capacity thereof, and agglomerates continuously spill over a dam ring g at the outlet end thereof which is of a height between <SP>1</SP>/ 40 and <SP>1</SP>/ 4 of the diameter or mean diameter of the drum. The particles are discharged from the drum to a sieving device or to a vertical pipe h wherein larger particles fall into a lock k and lightweight particles are raised by a fan i for cyclone separation and recycling to the drum. The drum may comprise a zone at the outlet end thereof defined between a dam e and the dam g and containing guide vanes f on the drum wall and into which dry power, e.g. voluminous sodium biphosphate, sodium triphosphate, magnesium silicate with detergents, or metal stearates for other than detergent compositions, may be fed by a screw d. The agglomerating drum may be without guide elements on the wall thereof and may be provided with a spring-pressed wall scraper. The lower generatrix of the drum may be horizontal or, preferably, inclined up to 10 degrees, e.g. 7¥ degrees with a cylindrical drum and movement of the powder towards the discharge end of the drum is assisted by the force of the liquid jets. In a frusto-conical drum with a horizontal axis, the spray jets are installed at the smaller end or alternatively, with the lower generatrix thereof inclined at 2 degrees, the spray jets, powder inlet and air exhaust are arranged at the large diameter end. The spraying of highly viscous liquids and slurries may be effected by compressed air jets and high pressure hydraulic pressure mixing jets may be used, or preferably, air pressure mixing jets may be employed, e.g. with air under pressure supplied from the outer of three concentric orifices from each of the inner whereof is supplied one liquid; hot air or steam may be employed. A swinging scraper, which is stationary during drum rotation, may be employed at the outlet end of the drum to complete emptying thereof after production.