RU2480693C2 - Drier with controlled swirl heat carrier flow - Google Patents

Abstract

FIELD: heating.

SUBSTANCE: in the drier with controlled swirl heat carrier flow, which contains a drying chamber with a waste heat carrier and dried material mixture outlet opening located in upper part of the drying chamber, with a tangentially installed branch pipe for supply of tangential heat carrier flow, a branch pipe for supply of wet disperse material and a branch pipe for supply of axial heat carrier flow, which is provided along the chamber axis in its lower part, a grid for retention of a product in case of the drier shutdown, a new feature is that a swirler is located in lower part of the branch pipe for supply of axial heat carrier flow, and a branch pipe is installed tangentially in its upper part for supply of additional heat carrier flow.

EFFECT: improvement of the dried product quality, intensification of the heat and mass exchange process, uniform swirling, simpler unloading of the product, reduction of production complexity and erection of the structure, and reduction of the drier metal consumption.

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Description

The invention relates to food, chemical and related industries and can be used for heat and mass transfer processes, namely drying of dispersed materials.

One of the main directions of intensification of heat and mass transfer processes is the improvement of the hydrodynamic situation in the apparatus. Drying methods based on the technology of the suspended layer, are currently becoming increasingly common in industry.

Closest to the proposed technical essence and the achieved result is a dryer with active hydrodynamics and after-treatment of the material [patent No. 2182297, F26B 17/10, bull. No. 13 publ. 05/10/2002], containing a drying chamber with a nozzle for inputting the starting material, divided into cylindrical sections, in the upper part of which there are cylindrical inserts located along the axis of the chamber and dividing it into zones, with tangentially installed nozzles for supplying an additional flow of the drying agent and a nozzle for supplying the main flow of the drying agent, made along the axis of the chamber in its lower part. The grille is designed to prevent particles from entering the duct. Pipes are provided in the lid for withdrawing the spent drying agent. The drying chamber consists of a chamber for unloading a dry product, cylindrical sections, in the upper part of which there are windows for material withdrawal and spent drying agent, which are annular slots, the geometry and quantity of which depends on the hydrodynamic properties and particle sizes of the processed material.

The known design has several significant disadvantages:

- low quality of the finished product due to the uneven swirling of the coolant flow and the initial dispersed material;

- insufficiently high intensity of the drying process;

- a complex system for controlling the swirl of the coolant flow;

- the difficulty of unloading the finished product;

- the complexity of the manufacture and installation of the dryer;

- uneven load on the holding grid.

An object of the invention is to improve the quality of the dried product, the intensification of the heat and mass transfer process, ensuring uniformity of twisting, simplifying the unloading of the product, reducing the complexity of manufacturing and installation of the structure, reducing the metal consumption of the dryer.

The object of the invention is achieved in that in a dryer with an adjustable swirling flow of coolant, containing a drying chamber with a window for discharging a mixture of waste coolant and dried material located in the upper part of the drying chamber, with a tangentially mounted pipe for supplying a tangential flow of coolant, a pipe for feeding wet dispersed material and a nozzle for supplying an axial flow of coolant, made along the axis of the chamber in its lower part, a grill for In case of stopping the product in case the dryer stops, it is new that a swirler is located in the lower part of the nozzle for supplying the axial flow of the coolant, and in the upper part of the nozzle there is a tangentially installed nozzle for supplying an additional coolant flow.

The technical result consists in improving the quality of the dried product, the intensification of the heat and mass transfer process, ensuring uniformity of twisting, simplifying the unloading of the product, reducing the complexity of manufacturing and installation of the structure, reducing the metal consumption of the dryer.

Figure 1 and figure 2 presents the dryer with an adjustable swirling flow of coolant.

The dryer (FIGS. 1, 2) consists of a cylinder-conical drying chamber 1 with a window 2 and a nozzle 3 for outputting a mixture of a dried product and waste heat carrier and a cover 5, a nozzle 4 for introducing the initial wet dispersed material, a nozzle 6 for supplying an axial flow of the heat carrier, in which in the lower part is concentrically located swirl 7, and in its upper part a pipe 8 is tangentially installed for supplying an additional coolant flow. The holding grid 8 is designed to prevent particles of material from entering the duct in the event of an emergency stop of the drying unit.

The trajectories of swirling coolant flows formed by the axial and tangential flows are shown by lines 10.

A dryer with an adjustable swirling flow of coolant works as follows.

Through the pipe 6 for supplying the axial flow of the coolant into the drying chamber 1, the hot coolant is supplied, passes through the swirl 7 and twists. Through the tangential pipe 8 an additional flow of hot coolant is supplied, which turns the main flow of the coolant to the desired twist intensity. After that, the initial wet dispersed material is fed into the drying chamber 1 through the pipe 4, where the drying process is intensively carried out in a suspension-swirling layer, while the core of the fountain of dispersed material rotates around the vertical axis of the dryer, coinciding with the direction of motion of the swirling flow, and thereby uniform tangential twisting in a weighted-twisted layer. The coolant together with the particles of the material performs a complex circulation movement along the circumference of the apparatus, while increasing its speed. The tangential velocity of the particles causes the appearance of a centrifugal force, which rejects particles from the center of the drying chamber to its walls, forming a suspended suspension layer - a rotating ring. In this case, the drying process proceeds in an unsteady mode at high relative velocities of the particles of material and coolant. The axial component of the velocity of the swirling flow decreases along the height of the drying chamber, the rate of product soaring decreases as it dries. Due to this, the product, as it dries, gushes out in a swirling coolant flow and rises to a great height along the axis of the drying chamber. The total flow rate of the coolant is selected in such a way that, having reached the required moisture content, the product is removed from the drying chamber, entrained by the spent coolant flow through the outlet window 2 and pipe 3 to output the mixture of the dried product and the spent coolant of the drying chamber 1. The final moisture content of the finished product is controlled by the axial and tangential coolant flows. By changing the tangential component of the coolant flow, it is possible to achieve maximum uniformity of swirling the flow of material and coolant, and by changing the axial component of the coolant flow, you can adjust the residence time of the product in the drying chamber, thereby significantly intensifying heat and mass transfer processes with other equal drying parameters.

In the event of an emergency stop of the dryer, the product is retained on the grill 9 and does not fall into the duct.

Thus, the proposed dryer with an adjustable swirling flow of coolant has the following advantages:

- allows you to get the finished product of higher quality, due to the organization of uniform swirling of the flows of material and coolant and due to the exclusion of its contact with the surface of the tangential ducts;

- thanks to the installation of the swirler, the energy costs for swirling the coolant flow are reduced;

- the organization of unloading of the finished product through the window into the pipe facilitates the process of unloading and collecting the finished product;

- simplifies the manufacturing and installation of the dryer, and also reduces the metal structure;

- due to the ability to control the swirl of the coolant flow and the residence time of the material in the drying chamber, the dryer can be configured for various drying modes of various kinds of dispersed materials;

- the proposed vortex dryer is universal, that is, it can be used in all industries where drying of dispersed materials is necessary.

Claims (1)

A dryer with an adjustable swirling flow of a heat carrier, comprising a drying chamber with a window for discharging a mixture of waste coolant and dried material located in the upper part of the drying chamber, with a tangentially mounted nozzle for supplying a tangential flow of coolant, a nozzle for supplying wet dispersed material, and a nozzle for supplying axial flow coolant, made along the axis of the chamber in its lower part, with a grill for holding the product in case the dryer stops, characterized in that izhney nozzle portion for supplying coolant axial flow swirler is located, and in its upper part tangentially mounted inlet for supplying additional coolant flow.

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