SU861898A1 - Distributing dryer - Google Patents

Description

The invention relates to a spray dryer of dispersed materials in the metallurgical, chemical, food and other industries.

Known spray dryer containing a cylindrical chamber with chordally placed nozzles for supplying coolant, the axes of which are located tangent to an imaginary circle, and a spray mounted on the axis of the chamber [1J.

This dryer is the closest to the invention in technical essence and the achieved result.

A disadvantage of the known spray dryer is the possibility of adhesion of the material to the walls of the chamber, uneconomical and low quality of drying.

The aim of the invention is to prevent sticking of the material to the walls of the chamber ^ increase the efficiency and quality of drying. .

This goal is achieved in that the chamber consists of two series-connected cylinders of different diameters, the smaller of some is 1.0-1.5 diameters of the indicated imaginary circle, and the nozzles are located from the output section of the smaller cylinder at a distance not exceeding 2d, where d is the diameter of the nozzle .

In FIG. 1 shows a spray dryer; in FIG. 2 is a section AA in FIG. 1.

The spray dryer contains a small cylinder 1, a large cylinder 2, a manifold 3 for heating gases, a nozzle 4 for supplying a coolant, a sprayer 5, a suction system 6 and an unloading unit 7.

Spray dryer operates as follows.

. Heated gases from the combustion device enter the manifold 3, then through nozzles 4 into the volume of a small cylinder, where as a result of the interaction between the chordal jets of the heated gas they form an intense vortex. The drying material and compressed air enter the atomizer 5, where the material is sprayed. The sprayed material is mixed with heated gases and then, in the process of joint movement, it is dried, enters the lower part of the cylinder. 2, from where it is removed through the unloading unit 7. The heat carrier saturated with water vapor is removed through the suction system 6.

When the chamber is made in the form of two sequentially installed coaxial cylinders of different diameters, a concentrated supply of the coolant flow to the root of the spray plume is provided, while the best conditions are created for the intensive interaction of the coolant flow with the spray plume in its root by reducing the distance from the heated gas nozzle to the root spray torch. In addition, this design allows the supply of heated gases from a smaller cylinder to a larger one in the form of a formed vortex of certain sizes, providing the best conditions for heat and mass transfer in the volume of a large cylinder. This significantly reduces the size of the recirculation zone around the outlet of each stream of the supplied coolant flow, which reduces heat loss through the lid and walls, limiting the size of the recirculation zone.

The proposed design of the vortex drying chamber provides a concentrated supply of the coolant flow to the root of the spray jet at a temperature of heated gases exceeding that permissible for dry material, helps to reduce the buildup of material on the walls of the chamber and to reduce heat loss through the wall, eliminates recirculation zones in the coolant supply area, reduces 10 reduces friction losses and the area of the high-temperature surface of the chamber, reduces hydraulic resistance due to the simple design of the inlet section .

Claims (1)

This invention relates to a spray dryer for dispersed materials in the metallurgical, chemical, fusion, and other industries. A known spray dryer containing a cylinder of a cylindrical shape with chordally placed nozzles for supplying coolant, the axes of which are tangential to an imaginary circle, and a spray gun mounted along the axis of chamber 1 J. This dryer is closest to the invention by technical essence and achievable result A disadvantage of the known spray dryer is the possibility of material adhering to the walls of the chamber, inefficiency and low quality of drying. The aim of the invention is to prevent material from sticking to the walls of the chamber, increasing the economy and quality of drying. . This goal is achieved by the fact that the chamber consists of two series-connected cylinders of different diameters, smaller than the diameter of 1.0-1.5 times the diameter of the indicated imaginary circle, and the nozzles are positioned from the upper section of the smaller cylinder at a distance not exceeding 2d where d is the diameter of the nozzle. FIG. 1 shows a spray dryer; in fig. 2 shows section A-A in FIG. 1. The spray dryer contains a small cylinder 1, a large cylinder 2, a collector 3 for heating gases, a nozzle 4 for supplying heat transfer fluid, a sprayer 5, a suction system 6 and a discharge unit 7. Spray dryer works as follows. 3 The heated gases from the combustion device enter the collector 3, then through the nozzles 4 into the volume of the small cylinder, where, as a result of the interaction of the chordal jets of the heated gas, they form an intense vortex. Drying material and compressed air flow into the atomizer 5, where the material spreads. The sprayed material is mixed with heated gases and then, in the process of joint motion, is dried, enters the lower part of the cylinder. 2, from where a black unloading unit 7 is removed. The heat carrier, as determined by steam, is removed through suction system 6. When the chamber is made in the form of two successively installed coaxial cylinders of different diameters, a concentrated supply of the heat transfer fluid to the root of the spray plume is provided, thereby creating the best conditions for the intensive interaction of the flow of heat transfer fluid with the spray of the sprayed material in its root by reducing the distance from the nozzle for heated gases up to the root of the spray torch. In addition, this design allows for the supply of heated gases from a smaller cylinder to a larger one in the form of a shaped vortex of a certain size, providing the best conditions for heat and mass transfer in the bulk of a large cylinder. At the same time, the size of the recirculation zone around the exit point of each stream of the heat transfer fluid decreases significantly, which reduces heat loss through the cap and walls, limiting the recirculation zone dimensions. The proposed design of the vortex drying chamber provides 4 concentrated supply of coolant to the spray root at a temperature of heated gases that exceeds the allowable for dry material, helps reduce material sticking to the chamber walls and reduce heat loss through the wall, eliminates recirculation zones in the area of coolant supply, reducing fading friction losses and the area of the high-temperature surface of the chamber, reduces the hydraulic resistance due to simple design of the inlet section . The invention includes a spray dryer comprising a cylindrical chamber with chordally placed nozzles for supplying coolant whose axes are tangential to an imaginary circle, and a spray gun mounted along the axis of the chamber, characterized in that, in order to prevent material from sticking to the chamber walls, efficiency and quality of drying, the chamber consists of two cylinders of different diameters connected in series, the smallest of which is 1.0-1.5 times the diameter of the indicated imaginary circle, m nozzles are arranged on the output section of the smaller cylinder at a distance not prevsch1ayuschem two nozzle diameters. Sources of information taken into account during the examination 1. A. Mikhaylenko. et al. Aerodynamics and optimization of vortex chambers for spray dryers. Industrial power engineering, 1977, No. 8, p. 34-38. J Offfffffe 4 zz J. ) -li ////one //// N f4ffi) A Yu /. /