GB674695A - Improvements relating to the sterilisation of liquid foodstuffs and beverages - Google Patents

Abstract

674,695. Sterilizing liquids. URSINA AKT.- GES. June 27, 1950 [June 27, 1949], No. 15994/50. Class 49. Liquid foodstuffs or beverages are sterilized continuously by heat treatment under pressure for a brief time to above 100‹ C. in a passage which is of circular cross-section and has no core or other insertion, a gaseous or vaporous heat carrier being introduced at the inner surface of the passage, and are thereafter cooled by lowering the pressure. Milk, and liquids containing milk, may, after preheating to 100‹ C. if desired, be heated by steam to a temperature between 170 and 250‹ C., the duration of such heating being less than one second. For fruit juices, the heat carrier is preferably carbon dioxide or nitrogen. With the apparatus of Figs. 1 and 2, milk is introduced at 2 into a straight passage 1 of constant circular crosssection in a tubular body 3 which has a jacket 7 containing steam introduced under pressure at 19, and the steam passing from the jacket 7 through passages 8 enters the milk by apertures 6; the apertures 6 are distributed along helical lines on the inner wall of the passage 1, and the size of the apertures decreases, and their spacing apart increases, with increase in distance from the milk inlet 2; the passages 8 are inclined in the direction of flow of the milk, for attainment of uniform flow thereof, and the passages 8 are also directed so that the entering steam imparts turbulence to the milk, for attaining uniform heating thereof. The parts bounding the flow path of the heat carrier, e.g. the passages 8 and the surfaces of the tubular body 3 bounding the hollow space 7, may be lined with a heat-insulating material.