GB1071850A - A process and apparatus for the treatment of powdered products particularly milk product powders - Google Patents

Abstract

1,071,850. Agglomerating milk powders. ETABLISSEMENTS LAGUILHARRE. March 11, 1965 [March 13, 1964; March 1, 1965], No. 10441/65. Heading A2E. [Also in Division B2] The agglomeration of powered products, particularly skim milk powder, is effected by producing a stream of the powder and at least one stream of a humidifying fluid, which streams are substantially in parallel and coaxial relation, and a stream of drying air, which stream is substantially parallel to and coaxial with the first two streams and surrounds them, rapidly contacting these different streams to achieve the humidification of the powder and immediate subsequent drying thereof, and then separating the dried agglomerated powder from the air. The stream of powder may be produced by mechanical feeding or by suspension in a carrying air stream. The powder may be supplied directly from a spray-drying process, such as that described and claimed in Specification No. 1,044,501. Powder conveyed at a velocity of 30-60 metres per second by an air flow (10 Kilograms powder per cubic metre of air) through a nozzle 1, Fig. 3, is humidified by steam, hot moisture-laden air, or a mixture of air and steam, passed at a velocity of 50-200 metres per second through nozzle 2, is conditioned as to its temperature and humidity by conditioning air passed through nozzle 23 and is dried by hot air at 140‹C. passed at a flow rate of 1500-2000 cubic metres per hour through nozzle 3. There may be two streams of steam &c., one located in the axis of the stream of powder and the other around the stream of powder (Fig. 5, not shown). Alternatively, a finely atomized aqueous liquid, such as water, or an aqueous solution or suspension of e.g. the same product as the powder to be agglomerated, may be employed, being delivered to within a stream of the powder travelling at 100-250 metres per second (Fig. 4, not shown). A vertical flow motion is imparted to the air stream which is charged with the powder, by introducing the powder tangentially into a cylindro-conical chamber for entrainment by the flowing air. The agglomerates are collected in a cyclone separator, and are then dried, cooled and graded on a vibratory refrigerating table; the finest particles are re-cycled.