SU1002031A2 - Vortex chamber for carrying out heat mass exchange process - Google Patents

Description

The invention relates to a technique of heat and mass transfer processes, c. Particularly for drying and gas cleaning of dispersed material, and can be used in agriculture, in food, chemical and other types of industries.

According to the main author. St. 946682 A known vortex chamber for heat-mass transfer processes, comprising a cylindrical body with a manifold for gas inlet and axial outlets and a twisting conical device with inclined blades, mounted axially inside the manifold for introducing gas}.

A disadvantage of the known vortex chamber is that the dispersed material is introduced into the axial region of the chamber. In the paraxial part of the vortex chamber there is a vacuum, therefore, the introduction of dispersed material into this region of the chamber is preferable. However, the presence of a layer of the material being processed in a swirling apparatus leads to the fact that the vacuum in the axial zone of the vortex chamber becomes insignificant (50-100 Pa), and in most cases

in the presence of a layer with a thickness of 10–20 mm in the axial zone of the vortex chamber, it is not vacuum that is observed, but pressure, therefore, it is impossible to introduce the dispersed material into the vortex chamber, since it is carried out by the gas stream leaving the chamber.

In addition, dispersed material. The feed from the paraxial zone to the already formed layer flows down along its inner surface practically without exchange with the processed material in the layer.

The purpose of the invention is to provide the possibility of separating the dispersed material and improving the heat exchange of the dispersed material with the coolant.

This goal is achieved by the fact that the vortex chamber for conducting heat-mass transfer processes is provided with bunker materials for loading and; discharging dispersed material installed respectively above and below the chamber and communicating with the camera through annular slots in the upper and lower walls of the chamber at the conical swirling machine .

The drawing shows a vortex chamber.

The chamber contains a collector 1 for inputting G-ase. tapering conical apparatus 2 with inclined slots, upper wall 3 with axial outlet nozzle, annular slot in upper wall 4, bunker 5 located above slot 4, lower wall b, made with slot 7 at the twisting apparatus, cleaned grain bunker 8, tightly adjacent to the body of the collector under the annular gap 7.

The camera works as follows

The grain from the hopper 5 through the annular slot 4 enters the upper part of the conical twisting device 2. After passing through the twisting device, the gas forms a vortex gas flow in the working volume of the chamber. The use of a conical swirling apparatus allows a gas stream having three speed components to be obtained; tangential, radial and axial. The axial velocity component is directed upwards. The grain material, under the influence of a swirling gas stream, forms in the upper part of the chamber a rotating layer of grain material. As it accumulates under the action of its own weight, it descends down the twisting device. It is purged with a gas stream. Since the upper wall 3 is made with a slit at the twisting apparatus, the dispersed material flowing through this slit to the twisting apparatus displaces down the already processed material, which contributes to a good heat-mass transfer between the gas and the dispersed material,

In the vortex chamber near the twisting apparatus, the pressure is maximum; therefore, to supply the grain material by gravity, it is necessary that the pressure in the lower part of the hopper communicating with the chamber be equal to the pressure near the twisting apparatus. This is ensured by the tight connection of the bunker with the loading slot and the presence in the bunker during operation of a sufficient amount of grain material, which prevents the gas stream from entering the chamber into the bunker. In order to ensure a good separating capacity of the device, it is necessary that the gas flow downstream of the layer of grain material be directed to the outlet axial nozzles in the upper and lower walls. Dense connection of the bunker in which sobi-. This is a clean material, with a vortex chamber prevents the gas suspension from getting into it, since the pressure in the bunker will be the same as in the vortex chamber.

On the current model, studies were conducted on the efficiency of separation of a grain pile, which had an initial contamination of up to 10%, which corresponds to the contamination of grain entering the elevator. The cleaning efficiency of the grain material from impurities that have greater aerodynamic resistance than the grain material was 99%. In this case, the pressure in front of the twisting apparatus did not exceed 3000 Pa. Vortex chambers with a dispersed phase duct and with loading into the near-region of the chamber have the effect of cleaning up to 70% (with a cylindrical twisting device — 40–50%, with a conical screw — up to 70%).

Experiments on heating the grain were also carried out on the model of the proposed device. This is necessary to intensify the drying processes in the mine grain dryers. The grain in the vortex chamber layer reached a predetermined temperature of 45 ° C for: 3-5 ° C at a coolant temperature of 70 ° C.

In existing mine dryers, the heating time of the grain to 45 ° C is several minutes at a temperature of the heat transfer medium of 130 ° C.

The development of the proposed technical solution was caused by the expediency of creating a compact chamber for cleaning the grain from light impurities and preheating it, which will intensify the drying process. As a result, the productivity of the mine grain dryer will increase by 15-20%.

The use of the proposed vortex chamber provides an improvement in heat and mass transfer with the flow of dispersed material through the chamber. This is achieved by better contact of the dispersed material with the gas (coolant).

Claims (1)

1. USSR author's certificate number 946682, cl. B 04 C 3/00, 1981 (prototype).