SU452732A1 - The method of spray drying solutions and suspensions - Google Patents

Description

one .

There are known methods for spray drying of solutions and suspensions by feeding them through nozzles lying on the same axis with two opposite jets in a flow with ring flows of heat-transfer agent,

The purpose of the proposal is to intensify heat and mass transfer and reduce the adhesion of the dried material to the chamber walls.

This goal is achieved by the fact that

The opposite peripheral annular flows of the heat transfer medium are asymmetrically relative to the vertical plane passing through the nozzle axis to form in the contact area of the jets a vertical vortex stabilized by introducing an additional flow of heat transfer fluid twisted in the horizontal plane into this zone.

FIG. 1 shows an installation (longitudinal section) in which the proposed method can be implemented;

see 2 is a section along A-A in FIG. one;

FIG. 3 is a section along BB in FIG. 2

The installation contains a horizontal camera 1, end distribution manifolds 2, nozzles 3 | asymmetrical peripheral annular nozzles 4, a box 5 with tangential nozzles, a central discharge nozzle 6, a central annular nozzle 7, and end caps 8.

The hot coolant supplied to the end distribution manifolds 2 passes through the asymmetrical certiferrial 4 and central 7 annular nozzles placed in the end caps 8 into the horizontal chamber 1, where the solution or suspension is sprayed simultaneously by the nozzles 3. Due to the fact that asymmetric peripheral annular nozzles 4 are placed with a diametrically opposed horizontal eccentricity, the hot coolant flowing from the side of maximum gaps passes along the walls of the chamber 1 and forms a vertical vortex in the zone of contact of the jets. To stabilize this vortex, an additional coolant flow twisted in a horizontal plane is introduced through the box 5 with tangential nozzles.

i Drain the spent heat with the dried material through the central outlet, which can be placed at the top or bottom of the chamber 1.

The vortex formed in chamber 1 contributes to an increase in the coefficients of heat (and mass transfer due to the unsteady motion of the particles of the material being dried and an increase in the residence time of the latter in the drying zone.

In addition, the vortex prevents the deposition of material in the lower part of chamber 1. The material sticking onto the wall of chamber 1 is prevented due to the effect of near-wall annular heat carrier fluxes.

Subject matter

The method of spray drying solutions and suspensions by feeding them through nozzles lying on the same axis with two opposing jets in a flow with ring flows of heat-transfer agent, characterized in that, in order to intensify heat and mass transfer and reduce adhesion of the material being dried onto the chamber walls, the opposite The annular flow of the coolant is asymmetrically relative to the vertical plane passing through the axis of the nozzles to form vertical jets into the contact area.

vortex stabilized by entering into this zone an additional coolant flow swirling in the horizontal plane. G ig.Z ig, 2