RU2008592C1 - Device for drying coking dispersed materials - Google Patents

Abstract

FIELD: convection drying. SUBSTANCE: device has body, heat carrier inlet window 3, outlet window 4 for gas suspended matter, charging gear 10, insertion located along axis of body. Body is in the form of vertical cylinder 1 and shell 2 adjoining to its top section. Truncated cone-shaped shell 2 has diameter of bigger base which is equal to diameter of cylinder 1. The insertion is in the form of Venturi tube 5 whose top ends are positioned in the plane of bigger base of conical shell 2. Between expanding portions 7 and narrowing portions 6 of Venturi tube 5 there is cylindrical shell 8 whose diameter is equal to minimal diameter of tube and which has radial cuts. Its inner surface in zone of holes is provided with folded blades. In circular space between top ends of Venturi tube and walls of conical shell is located twisting blade-type gear 9. Charging gear 10 is positioned above outlet window 4 for gas suspended matter. EFFECT: enhanced reliability. 3 cl, 4 dwg

Description

 The invention relates to techniques for convective drying of materials and can be used in mining, chemical and other industries.

 A device for drying dispersed materials [1], containing a Venturi pipe, a power unit, an unloading chamber. The high relative velocities between the coolant flow and the material in the neck of the venturi should contribute to the disaggregation of lumps of material and the intensity of drying.

 However, the short residence time of particles and lumps of material in the neck does not allow to completely disaggregate the lumps of material and qualitatively dry the material.

 More perfect for disaggregation and high-quality drying is a device for drying clumping dispersed materials [2], which contains a body in the form of a venturi pipe, a case window for entering the coolant and a gas suspension, inside the case there is a coaxial system of hollow truncated cones directed with smaller bases towards the input window heat carrier and partially entering one another with an annular gap, a corrugated tape is strengthened in each annular gap, the material loading unit is adjacent to the side wall of one of the pe torn along the coolant of the truncated cone.

 This device is adopted as a prototype.

 According to the prototype, the drying path from hollow truncated cones, the introduction of additional quantities of coolant into the annular gaps should ensure high-quality drying of clumping dispersed materials by increasing the drying zones and the residence time of particles and lumps of material in the drying path.

 The disadvantages of the prototype are as follows. The configuration of the truncated cones expanding upward and the presence of corrugated ribbon inserts in the annular gaps do not adequately penetrate new portions of fresh coolant into the main core of the gas suspension moving along the axis of the truncated cones starting from the material loading unit. The insufficient penetration of portions of fresh coolant into the core of the gas suspension, in which the bulk of the dried material is concentrated, does not allow for proper turbulence of the flow of the gas suspension, completely disaggregate the lumps of material, provide high values of heat and mass transfer coefficients and local temperature pressures between the coolant and materials, which ultimately affects the quality drying clumping dispersed material. The loading of the material into one of the truncated cones and thereby organizing the direct-flow movement of the material and coolant flows also limit the possibility of drying the clumping dispersed material for the reason that the acceleration section at which the highest relative velocities between the material lumps and the coolant flow are realized is short, thereby direct-flow movement limited drying capabilities.

 The purpose of the invention is to improve the drying quality of clumping dispersed materials by creating a gas suspension with high temperature pressures and heat and mass transfer coefficients between the lumps of material and the heat carrier flow throughout the drying path.

 This goal is achieved by the fact that in the device for drying clumping dispersed materials, comprising a housing, a window for introducing a coolant, a window for discharging a gas suspension, a loading device and an insert placed along the axis of the housing, the housing is made in the form of a vertically located cylinder and an adjacent shell in the form of a truncated cone with a diameter of a larger base equal to the diameter of the cylinder, and the insert is made in the form of a venturi, the upper ends of which are located in the plane of the larger base of the conical bechayki, and between the expanding and tapering sections of the Venturi pipe there is a cylindrical shell, the diameter of which is equal to the minimum diameter of the pipe made with radial slots, and bent blades are located on the inner surface in the shell zone, located in the annular gap between the upper ends of the Venturi pipe and the walls of the conical shell a twisting blade device, and the loading device is located above the gas suspension outlet window.

 The proposed device has the following distinctive features from the prototype features.

 The casing is made in the form of a vertical cylinder and a shell in the form of a truncated cone adjacent to its upper part with a diameter of a larger base equal to the diameter of the cylinder.

 An insert made in the form of a Venturi pipe is placed along the body axis, the upper ends of which are located in the plane of the larger base of the conical shell, and between the expanding and tapering sections of the Venturi pipe there is a cylindrical shell made with radial slots, curved blades are located on the inner surface in the shell zone.

 In the annular gap between the upper ends of the Veturi pipe and the walls of the conical shell there is a spinning blade device.

 The loading device is located above the gas suspension output window. Therefore, the proposed technical solution meets the criterion of "novelty."

 An analysis of the known technical solutions showed that apparatuses are known that are made in the form of a vertical cylindrical body with an adjacent conical shell [3,4], in which the shell serves for a smooth, continuous separation of the gas stream from the apparatus. In the inventive device, the conical shell is designed to enhance the rotational, vortex flow of the gas suspension stream at the outlet of the housing of the claimed device.

 In the technical solution [1] there is a venturi pipe with a continuous cylindrical shell - neck. In the inventive device, the Venturi pipe contains a cylindrical shell with radial slots and curved blades on its inner surface. Curved channels between bent blades facilitate ejection and swirling fresh portions of the coolant coming from the body into the cavity of the cylindrical shell to create a vortex, turbulent flow of gas suspension in it, which implements an intensive drying process with the simultaneous disaggregation of large lumps of material. The disaggregation of large lumps of material is carried out due to the vortices of the gas suspension flow and the impact of the discarded large lumps on the protrusions of the curved blades.

 A technical solution is known [5], in which the Venturi pipe has a cylindrical shell with vertical slots without curved blades, the slots are designed to eject part of the spent low-temperature coolant into the shell cavity. Such a technical solution does not allow to organize a swirl and a vortex flow in the cavity of the shell, to achieve high temperature pressure between the flow of the coolant and the material, which ultimately limits the possibility of drying and disaggregation of lumps of material. In the inventive device, the presence of a cylindrical shell with slots and with curved blades and ejection of fresh portions of the coolant into the cavity of the cylindrical shell provide an intensive vortex flow, the impact of large lumps on the protrusions of the blades with subsequent heat and mass transfer coefficients, which ultimately contributes to high-quality disaggregation and drying of the material inside the cylindrical cavity Venturi pipe shells.

 In the technical solution [1], the venturi outlet is in the plane of the largest section of the discharge chamber in order to provide conditions for better deposition of dried particles of material from the coolant flow in the discharge chamber. In the claimed device, the upper ends of the Venturi pipe are located in the plane of the larger base of the conical shell, which increases the speed and swirl of the gas suspension flow inside the conical shell and thereby partially disaggregates and dries the lumps of material loaded into the conical shell.

 A technical solution is known [6], containing a swirling device in a vortex dust collector in the form of an annular blade swirler for forming a wall spiral flow. In the inventive device in the annular gap between the upper ends of the venturi and the walls of the conical shell there is a swirling blade device that forms a swirling flow of fresh coolant, directed at an angle to the axial line of the conical shell for turbulization and the penetration of individual portions of fresh coolant into the flow of moist into the conical shell material for the purpose of preliminary disaggregation and drying of large lumps of material. The same fresh coolant flow in the conical shell provides complete disaggregation and drying of small lumps of wet material, as well as the final drying of the particles of gas suspended in the conical shell from the venturi.

 A technical solution is known [7], containing a loading device located coaxially above the venturi outlet. In the inventive device, the boot device is placed coaxially above the window for the exit of the gas suspension.

 Based on the analysis, we can conclude that although there are similar features with known technical solutions, in the proposed technical solution, the features have properties that distinguish it from the known ones.

 In FIG. 1 shows the proposed device; in FIG. 2 is a section AA in FIG. 1; in FIG. 3 - twisting blade device; in FIG. 4 is a fragment of a scan of a swirling blade device at the wall of the conical shell.

 The proposed device comprises a vertically located cylinder 1 with an adjacent conical shell 2, a window 3 for introducing a coolant, a window 4 for outputting a gas suspension. Inside the cylinder 1, an insert is installed in the form of a Venturi pipe 5, consisting of a tapering section 6, an expanding section 7 and a cylindrical shell 8 with slots and curved blades 11. In the annular gap between the walls of the conical shell 2 and the upper ends of the Venturi pipe 5 there is a spinning blade device 9 The loading device 10 is located coaxially above the window 4 for output of the gas suspension. Venturi pipe 5 is attached to the cylinder 1 by means of rods 12.

 A device for drying clumping dispersed materials works as follows. Portions of fresh coolant through the window 3 enter the tapering section 6 of the venturi and into the cavity of the cylinder 1. From the cavity of the cylinder 1, 20% of the coolant flow enters the cavity of the cylindrical shell 8, 25% of the coolant enters the swirling blade device 9, the remaining 55% of the coolant enters tapering section 6 of the venturi. Clumping dispersed material by the loading device 10 is fed into the central part of the cavity of the conical shell 2. In the conical shell 2, pre-drying and disaggregation of large lumps of material occurs, as well as drying of small lumps of material. The intensity of disaggregation of lumps and their drying in a conical shell 2 is determined by two factors: the countercurrent flow pattern of the coolant and the material, as well as the involvement of lumps of material in the vortex of the coolant, which is formed by the position of two flows - the gas suspension flowing out of the channels of the spinning blade device 9 and directed under angle to the vertical axis of the conical shell 2. Vortex flow captures small lumps from the flow of incoming material, which are the centrifugal force of the swirls to the periphery of the conical shell 2, where they finally disaggregate due to the action of vortices and mutual collision of the lumps of material, as well as their final drying in the flow of coolant flowing from the channels of the spinning blade device 9. The intensity of the disaggregation of the lumps and their drying in the cavity of the conical shell 2 is influenced by the factor that the vortex flow intensity increases along the height of the conical shell 2.

 The fact that the fresh coolant flow exiting from the swirling blade device 9 is directed at an angle to the vertical axis of the conical shell 2 allows individual portions of fresh coolant to penetrate the core of the flowing wet material and to ensure preliminary drying and disaggregation of lumps of material.

 Due to their weight, large lumps of wet material do not have time to be captured by the vortex flow in the conical shell 2 and fall into the expanding section 7 of the Venturi pipe, where due to the countercurrent flow pattern, high relative velocities between the material and the coolant are realized, and the relative velocity increases as penetration deep into section 7 of the venturi. An increase in the relative velocity leads to the fact that a large proportion of large lumps are dried and disaggregated in the cavity of section 7, the dried particles of material are pushed to the periphery of section 7 and are removed to the conical shell 2 by the flow of waste coolant, where they are finally dried.

 The largest lumps, which did not manage to disaggregate in the cavity of section 7 of the Venturi pipe, fall into the cavity of the cylindrical shell 8, where the vortex of the coolant is formed by the superposition of a high-speed flow of coolant emerging from the tapering section 6 and the coolant flow ejected from cylinder 1 through the slots between the bent blades 11 of the cylindrical shell 8. The vortex flow of the coolant and the impact of large lumps on the ends of the curved blades 11 manage to completely disaggregate the lumps and dry the material. The dried material along the peripheral zones of the venturi 5 is discharged into the peripheral zone of the shell 2 and through the window 4 the gas suspension is discharged from the device.

 Using the proposed device can improve the quality of drying to ensure uniform drying of all classes of clumping dispersed material. (56) 1. USSR author's certificate N 534625, cl. F 26 B 17/10. , published. 1975.

 2. USSR author's certificate N 907369, cl. F 26 B 17/10, published. 1982.

 3. A guide to dust and ash collection. M.: Energoatomizdat, 1983, p. 312.

 4. Gordon G. M. and Peysakhov I. L. Dust collection and purification of gases in non-ferrous metallurgy. M.: Metallurgy, 1977, p. 456.

 5. Copyright certificate of the USSR N 1372165, cl. F 26 B 17/10, published. 1986.

 6. Sazhin B. S. and Gudim L. I. Dust collectors with counter swirling flows. M.: NIITEhim, 1982.

 7. Copyright certificate of the USSR N 576503, cl. F 26 B 17/10, published. 1976.

Claims (3)

 1. DEVICE FOR DRYING CLOSED DISPERSED MATERIALS, comprising a housing, a window for introducing a coolant, a window for discharging gas suspension, a loading device and an insert located on the axis of the housing, characterized in that, in order to improve the quality of drying, the housing is made in the form of a vertically arranged cylinder and adjacent to its upper part of the shell in the form of a truncated cone with a diameter of a larger base equal to the diameter of the cylinder, and the insert is made in the form of a venturi, the upper ends of which are located in the plane of the larger base Nia conical shell, wherein between the expanding and narrowing portions Venturi tube arranged cylindrical shell with a diameter equal to the minimum diameter of pipe, performed with the radial slots on the inner surface of which openings are arranged in the zone of curved blades.  2. The device according to p. 1, characterized in that in the annular gap between the upper ends of the venturi and the walls of the conical shell is a spinning blade device.  3. The device according to p. 1, characterized in that the boot device is located above the output window of the gas suspension.

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