GB995742A - Fluidising apparatus and method for cooling solid particles and particulate products - Google Patents

Abstract

995,742. Cooling particulate material; cooling peas and berries. FRIGOSCANDIA Ltd. Nov. 6, 1961 [Nov. 7, 1960; June 7, 1961; Sept. 22, 1961], No. 39719/61. Headings F4H and F4U. Apparatus for freezing food particles, e.g. peas and berries, comprises a container 1, means 4 whereby the particles are fed into the container, means for forcing refrigerated air or gas into the container, and means 5 for allowing the particles to discharge from the container and wherein the air or gas fluidizes, freezes and transports the particles through the container. As shown, the food particles form a fluidized bed 3, the lower boundary of which is formed by perforated bottom 2, e.g. of plastics material through which fluidizing air flows. The supply device may consist of a shaking conveyer 27 inclined downwardly towards the container 1 operated by a vibrator 26 and adapted with at least one tongue 28 at its free end which oscillates and spreads the particles so that they are delivered to the fluidized bed 3 in spaced-apart relationship. The tongue is divided into flaps (Fig. 11, not shown) which are equal in size and taper towards their free ends. In a modification, the flaps may be of different shapes. The perforated bottom 2 may be inclined downwards from the supply end (Fig. 2, not shown) and may be designed to impart a direction of flow to the air flowing through it, either by forming the perforations at an angle to the horizontal plane (Fig. 5, not shown) or if the bottom is very thin with vanes (Fig. 6, not shown). The container walls may be inclined outwardly from the bottom and may be provided with perfortions (Fig. 3, not shown). They may also be provided with horizontal baffles 8. Besides the overflow 5, the container may have an outlet 20 containing a valve 21 situated near the perforated bottom 2. The container may be provided with a shaking device imparting longitudinal vibrations thereof, the shaking device may, however, be provided within the fluidized bed. In a further embodiment (Figs. 8 and 9, not shown), the container is designed to have a calm zone near the outlet end and within this zone a blower means directed towards a suction means both connected to the same fan system, and between the suction and blow means a separator for trapping undesirable elements. The space 10 beneath the perforated bottom 2 may be divided into sections, each section having a fan which is supplied with air by a common fan (Fig. 4, not shown). The air driven by one or more fans 17 is adapted to pass through a cooling battery 18 situated downstream of the fans in the air circuit. The container 1 may be equipped with a partition to separate the different processes of " glazing " and freezing.