RU2490571C2 - Chamber for heat and mass exchange between dispersed particles and gaseous medium - Google Patents

Abstract

FIELD: heating.

SUBSTANCE: in a chamber for heat and mass exchange between dispersed particles and a gaseous medium, comprising a body with a cover, a vessel with porous walls installed inside the body concentrically to it, nozzles installed inside the vessel and a device for bleeding of the spent coolant with the porous working surface, equipped with a drive, and inside the vessel there are lattices fixed, between which there is a layer of an inert carrier filled, which increases efficiency of heat and mass exchange. To increase efficiency of operation of the inert carrier, at least two rods are connected to the rotary hollow porous cylinder, and their axes are parallel to the axis of the cylinder, and are at identical distance from its axis, and to each of rods at the angle of 45…90° there are additional rods attached, making it possible to intensify heat and mass exchange between coolant and dispersed material, according to the invention, the body of the nozzle is made with a channel for liquid supply and comprises a coaxial rigidly connected bushing, with a nozzle fixed in its lower part made in the form of a cylindrical double-staged bushing, the upper cylindrical stage of which is connected by means of a threaded joint with a central core, made of a cylindrical part and a coaxial conical socket installed with a circular gap relative to the inner surface of the cylindrical bushing, and the circular gap is connected at least with three radial channels made in the double-staged bushing, connecting it with the circular cavity, formed by the inner surface of the bushing and the outer surface of the upper cylindrical stage, besides, the circular cavity is connected with the channel of the body for liquid supply, at the same time to the conical socket, in its lower part, there is a receptacle rigidly fixed in the form of an end round plate with at least seven radial tabs, which are bent towards the circular gap between the nozzle and the socket, on the side surface of the socket there are at least two rows of cylindrical throttling holes, with axes lying in planes perpendicular to the socket axis, and in each row there are at least three holes, besides, in the end round plate there are at least three conical throttling holes with an angle near the top of the cone lying in the range of 45° - 90°.

EFFECT: higher efficiency of drying and tempering processes.

2 dwg

Description

The invention relates to a device for carrying out heat and mass transfer processes, mainly drying in suspension.

Closest to the claimed object in technical essence is a chamber according to the patent of the Russian Federation No. 2334181, F26B 3/12, designed for heat and mass transfer between liquid or solid particles and a gaseous agent, made in the form of a closed vessel of cylindrical shape of variable volume with porous walls, and sprays ( prototype).

However, the use of a cylindrical vessel of variable volume does not allow the known design to carry out heat and mass transfer of droplets while continuously removing heat carrier from the chamber, which sharply limits its productivity and, accordingly, excludes the possibility of using heat and mass transfer under industrial conditions during spray drying.

EFFECT: increased productivity by continuous removal of spent heat carrier.

This is achieved by the fact that in the chamber for conducting heat and mass transfer between dispersed particles and a gaseous medium containing a housing with a cover, a vessel with porous walls placed concentrically to it, located inside the nozzle vessel and an exhaust heat transfer device with a porous working surface, equipped with a drive, and inside the vessel there are lattices fixed, between which a layer of inert support is poured, which increases the efficiency of heat and mass transfer, while increasing the efficiency of work At least two rods are attached to the rotating hollow porous cylinder; at least two rods are attached, the axes of which are parallel to the axis of the cylinder and are at the same distance from its axis, and additional rods are attached to each of the rods at an angle of 45 ... 90 °, which allow intensifying heat and mass transfer between the coolant and the dispersed material, according to the invention, the nozzle body is made with a channel for supplying liquid and contains a coaxial sleeve rigidly connected to it, with a nozzle fixed in its lower part, in the form of a cylindrical two-stage sleeve, the upper cylindrical step of which is connected via a threaded connection to a central core consisting of a cylindrical part, and a conical bell arranged coaxially with it, installed with an annular gap relative to the inner surface of the cylindrical sleeve, and the annular gap is connected at least with three radial channels made in a two-stage sleeve connecting it with an annular cavity formed by the inner surface of the sleeve and the outer the surface of the upper cylindrical stage, and the annular cavity is connected with the channel of the housing for supplying fluid, while the conical socket in its lower part is rigidly attached to the socket in the form of an end circular plate with at least seven radial petals that are bent towards the annular the gap between the nozzle and the bell, at least two rows of cylindrical throttle holes are made on the side surface of the bell, with axes lying in planes perpendicular to the axis of the bell, and in each row At least three openings are provided, and at least three conical throttle openings are made in the end round plate with an angle at the apex of the cone lying in the range from 45 ° to 90 °.

Figure 1 presents a diagram of the proposed camera, figure 2 is a diagram of the nozzle.

A vessel 2 with porous walls is coaxially located in the housing 1, forming a free space for uniform passage of the coolant into the vessel 2. The housing 1 and the vessel 2 are cylindrical. The coolant is supplied and discharged through nozzles 3 and 4. Particles are supplied or liquid is sprayed into the vessel 2 using nozzle 5. Depending on the performance of the chamber in an industrial environment, solids can be supplied or liquid can be sprayed with several nozzles (nozzles) 5, evenly located throughout the cross section of the vessel 2. The removal of the dry product is carried out by opening the porous bottom 6, fixed in the lower part of the vessel 2 with a cover 7. Day of removal of coolant volume of the vessel 2 is provided a hollow porous rotating cylinder 8, with perforated (porous) grating 19 on the bottom. The cylinder 8 is connected via a shaft 9 to the drive 10. The cylinder 8 is half the length of its working surface outside the housing 1, i.e. its parts located inside the vessel 2 and in the cavity 11 between the upper wall of the housing 1 and the upper cover 12 are equal. This allows you to reduce hydraulic losses during the removal of the coolant. Removal of the finished product is carried out from the hopper 13 connected to the discharge pipe 14. Inside the vessel 2, lattices 15 and 16 are fixed, between which a layer of inert carrier 20 is poured, which increases the efficiency of heat and mass transfer. To increase the efficiency of the inert carrier 20, at least two rods 17, the axes of which are parallel to the axis of the cylinder 8, and are at the same distance from its axis, are attached to the rotating hollow porous cylinder 8. Additional rods 18 are attached to each of the rods 17 at an angle of 45 ... 90 °, which makes it possible to intensify the heat and mass transfer between the coolant and the dispersed material.

The nozzle (figure 2) contains a cylindrical hollow body 21 with a channel 23 for supplying fluid and coaxially connected to the body of the sleeve 22 with a nozzle fixed in its lower part, made in the form of a cylindrical two-stage sleeve 24, the upper cylindrical step 26 of which is connected by a threaded connection with the Central core, consisting of a cylindrical part 27 and coaxial with it a conical socket 28 mounted with an annular gap 29 relative to the inner surface of the cylindrical sleeve 24. The annular gap 29 connected with at least three radial channels 25, made in a two-stage sleeve 24, connecting it with an annular cavity 34 formed by the inner surface of the sleeve 22 and the outer surface of the upper cylindrical stage 26, and the annular cavity 34 is connected with the channel 23 of the housing 21 for supply liquids.

A conical socket 28, in its lower part, is rigidly attached to a socket in the form of an end circular plate 31 with at least seven radial petals 32, which are bent towards the annular gap 29 between the nozzle and the socket. At least two rows of cylindrical throttle holes 30 are made on the side surface of the socket, with axes lying in planes perpendicular to the axis of the socket 28, and at least three holes 30 are made in each row. In the end circular plate 31, at least three conical throttle holes 33 with an angle at the apex of the cone lying in the range from 45 ° to 90 °.

The camera operates as follows.

The coolant with the set temperature and humidity enters through the pipe 3 into the free space between the walls of the housing 1 and the vessel 2, as well as between the lid 7 and the porous bottom 6. Under the influence of the pressure created, for example by a fan, the coolant penetrates through the pores of the walls of the vessel 2 into this vessel . Here, heat and mass transfer occurs between the coolant and drops or particles continuously supplied by means of a nebulizer (nozzle) 5. The dropping of particles or particles occurs on an inert carrier 20, and is prevented on the walls of the vessel 2 by organized blowing of them from the walls by the coolant entering through the pores. Under the influence of the aforementioned pressure, the coolant also passes through a layer of an inert carrier 20 located between the grids 15 and 16, as well as the pores of the rotating hollow porous cylinder 8, then enters its internal volume and then through the cavity 11 to the nozzle 4. Removing dry particles formed as a result of heat and mass transfer is carried out when removing the cover 7, and accordingly, the porous bottom 6. Under industrial conditions, the finished product is removed through the discharge pipe 14 connected to the hopper 13.

The described chamber can be used in a production environment for unbalanced drying in suspension, which will eliminate the loss of the finished product. Using this camera will prevent air pollution.

Liquid under pressure is supplied to the cavity of the nozzle body 21 and then flows in two directions: the first into the annular cavity 34 through radial channels 25 into the annular gap 29 between the nozzle and the central core. At inlet pressures of more than 0.2 MPa, the liquid accelerates on the external conical surface of the socket 28 with the formation of a liquid film that does not tear off from the external surface of the socket 28. Acceleration of the liquid on the conical surface is accompanied by a decrease in the static pressure in it and, as a result, vaporization and the formation of soluble gases. This phenomenon further prepares the liquid for crushing into small drops. Upon reaching the liquid flow of the oncoming flows flowing out of the cylindrical throttle holes 30, multiple crushing of the film occurs with the formation of a finely dispersed phase.

The second direction in which the fluid enters is through the channel 23 for supplying fluid to the cavity of the central core, and then to the conical socket 28, from which part of the fluid flows through the radial holes 30, and part through the conical throttle holes 33. In this case, multiple droplet crushing occurs fluid flows flowing from throttle openings.

The presence of gas inclusions in a liquid additionally perturbs its surface, which leads to wave formation and volumetric crushing of the liquid film. The loss of mechanical energy during external acceleration (on the external conical surface) is reduced compared with the same acceleration in a closed channel.

Claims (1)

A chamber for conducting heat and mass transfer between dispersed particles and a gaseous medium, comprising a housing with a lid, a vessel with porous walls located concentrically to it, located inside the vessel of the nozzle and a device for selecting the spent heat carrier with a porous working surface, equipped with a drive, and gratings are fixed inside the vessel, between which a layer of inert carrier is poured, which increases the efficiency of heat and mass transfer, while increasing the efficiency of the inert carrier to rotate at least two rods are attached to the expanding hollow porous cylinder, the axes of which are parallel to the axis of the cylinder and are at the same distance from its axis, and additional rods are attached to each of the rods at an angle of 45 ... 90 °, which allow intensifying heat and mass transfer between the heat transfer agent and the dispersed material, characterized in that the nozzle body is made with a channel for supplying fluid and contains a coaxially rigidly connected sleeve with a nozzle fixed in its lower part, made in the form of a cylindrical a two-stage sleeve, the upper cylindrical step of which is connected by a threaded connection to a central core consisting of a cylindrical part and a conical socket coaxially mounted therewith with an annular gap relative to the inner surface of the cylindrical sleeve, and an annular gap connected to at least three radial channels made in a two-stage sleeve connecting it with an annular cavity formed by the inner surface of the sleeve and the outer surface of the upper cylinder a stage, and the annular cavity is connected with the channel of the housing for supplying fluid, while the conical socket in its lower part is rigidly attached to the socket in the form of an end circular plate with at least seven radial petals that are bent towards the annular gap between the nozzle and at the bell, at least two rows of cylindrical throttle holes with axes lying in planes perpendicular to the axis of the bell are made on the lateral surface of the bell, and at least three holes are made in each row Stia, wherein a circular end plate holds at least three conical throttle opening angle at the apex of the cone lying in the range from 45 ° to 90 °.

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