SU823784A1 - Vortex spray-type dryer - Google Patents

Description

one

The invention relates to a drying technique and can be widely used in the food, chemical and other industries.

The known vortex spray dryer contains a flat bottom chamber and a sprayer and a scraper mechanism for removing the dry material 1 in its lower part.

The disadvantages of such a dryer are the considerable size and the impossibility of agglomerating the particles in the desired one. degree.

The purpose of the invention is the agglomeration of dry material particles in the chamber volume.

This goal is achieved by the fact that the mechanism is provided with an intake box, open at the bottom and forming an annular channel in its upper part.

FIG. 1 is a schematic representation of a vortex spray dryer, a general view; in fig. 2 is a view A in FIG. FIG. 3 is a section BB in FIG. 2

The dryer contains a flat bottom chamber 1 and a sprayer 3 placed in its lower part and a scraper mechanism 4 for removing dry material, the mechanism 4 being provided with a fence box 5, open at the bottom and about (annular channel 6 with the sprayer 3 in its upper part .

The dryer works as follows.

The heated air with a speed exceeding 50 m / s enters chamber 1, where, after acquiring a whirling motion, it is lowered into the lower part of chamber 1. After mixing in the lower part of chamber 1 with the solution sprayed through the atomizer 3, the heat carrier in the ascending inner spiral is withdrawn from camera 1 and is sent for cleaning.

The vortex motion of the coolant creates a cyclonic effect, due to which dry particles formed from drops of the sprayed solution,

are separated from the coolant and the powder is collected at the bottom 2 of the chamber 1. It is desirable that the rotation direction of the vortex and the atomizer 3 coincide.

With the rapid rotation of the gas flow due to centrifugal force in chamber 1, a significant pressure differential occurs between the central and peripheral regions. However, in the intake box 5, the rotation of the gas

There is also no inside box 5, there is no centrifugal force against the pressure difference between the central and peripheral areas of chamber 1. The pressure drop therefore causes an intense movement of the coolant in the box 5, directed from the periphery to the center. The heat carrier enters the box 5. through the open outer end and the gap between the walls of the box 5 and the bottom 2 of the chamber 1 and, entraining powder particles from the bottom 2 of the chamber 1 under the box 5, is discharged through an annular outlet in the center of the chamber 1 near the sprayer along with fine powder fractions. Large particles through the discharge channel under the force of gravity are removed from chamber 1 and enter a mechanical or pneumatic conveyor. At the same time, in order to separate large particles from small particles, it is advisable to create an upward air flow with a speed somewhat lower than the speed of movement of large particles. Once in the spray area, small dry particles form larger agglomerates with wet particles and, after drying, settle to the bottom 2 of the chamber 1, from which they are removed by the flow of heat transfer fluid in the duct 5 to the discharge channel if their size has reached a predetermined size. Otherwise, they are transported with a coolant to the spray area, where further agglomerate aggregation takes place.

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Claims (1)

(o) ooo / o / b / o Unloading of large particles from chamber 1 occurs periodically, during the remaining time of movement of the box 5, large particles accumulate in it and separate them from small ones. The movement of the box 5 and the rotation must be directed towards each other. The gap between the walls of the duct 5 and the bottom 2 of the chamber 1. must be open from the side of the running eddy. The proposed embodiment of the dryer allows to obtain a powder of uniform particle size, significantly reducing its entrainment. Claims of the Invention A vortex spray dryer comprising a flat bottom chamber and a sprayer and a scraper mechanism for removing the dry material in its lower part, characterized in that, in order to agglomerate the dry material particles in the chamber volume, the mechanism is provided with a suction box open at the bottom and forming with a spray in the upper part of the annular channel. Sources of information taken into account during the examination 1. A. Fokin. and others. Spray drying installations. M., NIImash, 1966, p. 12.