CN112742049A

CN112742049A - Rotary flash dryer

Info

Publication number: CN112742049A
Application number: CN201911046533.2A
Authority: CN
Inventors: 赵利民; 王晶晶; 金平; 王海波
Original assignee: China Petroleum and Chemical Corp; Sinopec Dalian Research Institute of Petroleum and Petrochemicals
Current assignee: Sinopec Dalian Petrochemical Research Institute Co ltd; China Petroleum and Chemical Corp
Priority date: 2019-10-30
Filing date: 2019-10-30
Publication date: 2021-05-04
Anticipated expiration: 2039-10-30
Also published as: CN112742049B

Abstract

The invention discloses a spin flash dryer, which comprises: the cylinder body is of a cylindrical structure and sequentially comprises a rotary drying section, an impact drying section and a grading section from bottom to top, a product outlet is formed in the upper part of the cylinder body, and an air inlet is formed in the lower part of the cylinder body; the classifier is arranged in the cylinder body and is lower than the product outlet; the rotating shaft coaxially penetrates through the bottom of the cylinder body, the rotating shaft is a hollow shaft, and materials enter the cylinder body through the rotating shaft; at least one disperser coaxially communicated outside the rotating shaft for dispersing the materials; at least one layer of stirring paddle which is coaxially connected outside the rotating shaft; and the gas distributor is arranged at the lower part of the cylinder in a surrounding way, the outer side of the gas distributor is communicated with the hot air, and the inner side of the gas distributor is communicated with the air inlet of the cylinder. The rotary flash evaporation dryer can process materials with high viscosity and high moisture content, and has the advantages of good drying effect and stable operation.

Description

Rotary flash dryer

Technical Field

The invention relates to the technical field of drying equipment, in particular to a rotary flash evaporation dryer.

Background

The rotary flash evaporation dryer is a vertical fluidized bed dryer with a crushing device, and is a high-efficiency and quick combined dryer capable of crushing and drying pasty materials at one time. The hot air enters the crushing chamber from the annular space at the bottom of the dryer, the contact surface area of the materials with the hot air is increased after the materials are crushed, the materials are further micronized while being dried through mechanical impact, centrifugal shearing and friction crushing, and qualified products are discharged from the upper part of the dryer under the entrainment of rotating airflow. However, when the material with high viscosity and too high moisture content is dried by spin flash, the material is easy to agglomerate when being stirred and crushed by spin flash. If low-temperature drying is adopted, the caking materials are difficult to dry, equipment is easy to block, and the drying process is difficult to perform; if high-temperature drying is adopted, the material is easy to denature.

Chinese patent document CN206146147U provides a novel energy-saving composite flash dryer for crushing and drying various powders, filter cakes, viscosity and thin materials, which utilizes efficient convection heat transfer drying to replace swirl flash drying, and through the indirect heat transfer mode of clamping a sleeve, can heat the material at the wall of a rotary drum, solves the problem that the scraper in the rotary drum can not effectively remove the material stuck at the wall of the rotary drum, but is not a true rotary flash dryer, and has no product granularity grading function, and the drying effect is worse than the rotary flash drying.

When carrying out the drying to the material that the viscidity is big and moisture content is too high, the material is constantly dry and the viscosity constantly increases in the whereabouts process, and the material is at first with the adhesion of drying chamber inner wall and then can the adhesion each other, "bridging" phenomenon appears, gathers more moreover, leads to drying chamber airflow channel to block up, can influence going on of drying process when serious.

The information disclosed in this background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

Disclosure of Invention

One of the objects of the present invention is to provide a spin flash dryer which can solve the problem that the prior art dryer is difficult to handle the material with high viscosity and high moisture content.

To achieve the above object, the present invention provides a spin flash dryer, comprising: the cylinder body is of a cylindrical structure and sequentially comprises a rotary drying section, an impact drying section and a grading section from bottom to top, a product outlet is formed in the upper part of the cylinder body, and an air inlet is formed in the lower part of the cylinder body; the classifier is arranged in the cylinder body and is lower than the product outlet; the rotating shaft coaxially penetrates through the bottom of the cylinder body, the rotating shaft is a hollow shaft, and materials enter the cylinder body through the rotating shaft; at least one disperser coaxially communicated outside the rotating shaft for dispersing the materials; at least one layer of stirring paddle which is coaxially connected outside the rotating shaft; and the gas distributor is arranged at the lower part of the cylinder in a surrounding way, the outer side of the gas distributor is communicated with the hot air, and the inner side of the gas distributor is communicated with the air inlet of the cylinder.

Further, among the above-mentioned technical scheme, spin flash dryer still includes: the collecting cavity surrounds the outside of the cylinder below the classifier and is communicated with the inside of the cylinder through an annular air outlet; the main flow inlet of the Venturi mixer is communicated with hot air, and the secondary flow inlet of the Venturi mixer is communicated with the collecting cavity; and the gas redistributor is arranged outside the cylinder in a surrounding manner and positioned above the gas distributor, the outer side of the gas redistributor is communicated with the outlet of the Venturi mixer, and the inner side of the gas redistributor is communicated with the inside of the cylinder through an annular air inlet.

Furthermore, in the above technical scheme, the annular air inlet is arranged corresponding to the disperser.

Further, in the above technical scheme, the gas redistributor is in a volute structure, and hot air enters the gas redistributor along the tangential direction.

Further, in the above technical scheme, the bottom of the cylinder is in an inverted cone structure.

Further, in the above technical scheme, the gas distributor is in a volute structure, and hot air enters the gas distributor tangentially.

Further, among the above-mentioned technical scheme, the barrel bottom includes the annular baffle, forms the air inlet between the bottom surface of annular baffle and barrel, and the air inlet is the annular.

Further, among the above-mentioned technical scheme, the tip of stirring rake is equipped with the scraper blade.

Further, in the above technical solution, the disperser is a pressure disperser or a rotary disperser.

Further, in the above technical solution, the rotary disperser is disc-shaped or conical.

Further, among the above-mentioned technical scheme, deconcentrator and stirring rake set up along axial looks interval.

Compared with the prior art, the invention has the following beneficial effects:

1. the bottom feeding and the disperser are matched for feeding, so that the materials are dispersed to form fog particles, the uniform distribution of the materials is facilitated, and the drying effect is improved.

2. The disperser disperses the material into fine droplets for pre-drying to form gas-solid two-phase airflow containing semi-dry particles, thereby reducing the phenomena of wall adhesion and bridging of the material.

3. By arranging the collecting cavity, the gas redistributor and the Venturi mixer, larger particles left in the cylinder body through the classifier are collected to the collecting cavity, mixed with hot air through the Venturi mixer, and enter the cylinder body through the annular air inlet by the gas redistributor to form rotary radial gas-solid two-phase airflow which flows and collides with the dispersed fog particles of the disperser at high speed to form a highly turbulent collision area, so that the heat and mass transfer process is strengthened, the occurrence of a 'bridging' phenomenon is avoided, and the long-period stable operation of the rotary flash evaporation dryer is ensured.

4. The gas distributor is of a volute structure, hot air enters the gas distributor tangentially, enters the barrel through the annular air inlet to rotate and rise, and the materials dispersed by the disperser are further dried and crushed under the action of the stirring paddle and the airflow in high-speed rotation motion to form a rotating floating particle group which is sent to the classifier for separation.

5. The end part of the stirring paddle is provided with a scraper blade, so that materials stuck on the inner wall of the cylinder body can be removed, and the phenomenon of scabbing is avoided.

6. Set up multilayer deconcentrator and stirring rake, the two interval sets up, can improve the homogeneity that the material distributes, drying effect is better.

The foregoing description is only an overview of the technical solutions of the present invention, and in order to make the technical means of the present invention more clearly understood and to make the technical means implementable in accordance with the contents of the description, and to make the above and other objects, technical features, and advantages of the present invention more comprehensible, one or more preferred embodiments are described below in detail with reference to the accompanying drawings.

Drawings

Fig. 1 is a schematic structural view of a spin flash dryer according to an embodiment of the present invention.

Description of the main reference numerals:

10-cylinder, 11-product outlet, 12-air inlet, 13-annular baffle, 14-annular air inlet, 15-annular air outlet, 20-rotating shaft, 21-disperser, 22-stirring paddle, 221-scraper, 23-shaft seal, 24-shaft driving device, 25-rotating joint, 31-gas distributor, 311-hot air inlet, 32-gas redistributor, 321-support plate, 40-classifier, 50-collection cavity, 60-venturi mixer, 61-main flow inlet, 62-secondary flow inlet and 63-outlet.

Detailed Description

The following detailed description of the present invention is provided in conjunction with the accompanying drawings, but it should be understood that the scope of the present invention is not limited to the specific embodiments.

Throughout the specification and claims, unless explicitly stated otherwise, the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element or component but not the exclusion of any other element or component.

Spatially relative terms, such as "below," "lower," "upper," "above," "upper," and the like, may be used herein for ease of description to describe one element or feature's relationship to another element or feature in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the object in use or operation in addition to the orientation depicted in the figures. For example, if the items in the figures are turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" the elements or features. Thus, the exemplary term "below" can encompass both an orientation of below and above. The article may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative terms used herein should be interpreted accordingly.

In this document, the terms "first", "second", etc. are used to distinguish two different elements or portions, and are not used to define a particular position or relative relationship. In other words, the terms "first," "second," and the like may also be interchanged with one another in some embodiments.

As shown in fig. 1, a spin flash dryer according to an embodiment of the present invention includes: the barrel 10 is of a cylindrical structure, and the barrel 10 sequentially comprises a rotary drying section, an impact drying section and a grading section from bottom to top. The upper part of the cylinder 10 is provided with a product outlet 11, and the lower part is provided with an air inlet 12. A classifier 40 is provided in the cylinder 10, and the classifier 40 is located below the product outlet 11. The rotating shaft 20 coaxially penetrates through the bottom of the cylinder 10, the rotating shaft 20 is a hollow shaft, and materials enter the cylinder through the rotating shaft 20. A disperser 21 is coaxially communicated outside the rotating shaft 20, and the disperser 21 can disperse the material into fine mist particles. At least one layer of stirring paddle 22 is coaxially connected outside the rotating shaft 20 to stir and cut the material. The lower portion of the drum 10 is provided with a gas distributor 31 around the circumference, and the outside of the gas distributor 31 communicates with hot air, for example, through a hot air inlet 311, and the inside communicates with the air inlet 12 of the drum 10.

Further, in one or more exemplary embodiments of the present invention, the spin flash dryer further includes: a collection chamber 50, a venturi mixer 60, and a gas redistributor 32. The collection chamber 50 surrounds the exterior of the drum 10 below the classifier 40 and communicates with the interior of the drum 10 through the annular air outlet 15. The primary inlet 61 of the venturi mixer 60 is in communication with the heated air and the secondary inlet 62 is in communication with the collection chamber 50. The gas redistributor 32 is arranged around the cylinder 10 and above the gas distributor 31, the outer side of the gas redistributor 32 is communicated with the outlet 63 of the venturi mixer 60, and the inner side is communicated with the inside of the cylinder 10 through the annular air inlet 14.

Preferably, but not limitatively, in one or more exemplary embodiments of the present invention, the annulus air inlets 14 and the dispersers 21 may be correspondingly arranged, the number of the annulus air inlets 14 is the same, or the number of the annulus air inlets 14 is greater than the number of the dispersers 21, which is not limited by the present invention.

Further, in one or more exemplary embodiments of the present invention, the gas redistributor 32 is a volute structure, and the hot air enters the gas redistributor 32 tangentially.

Further, in one or more exemplary embodiments of the present invention, when the annulus air inlet 14 is plural, the gas redistributor 32 is provided with a supporting plate 321 for supporting the cylinder 10 connected between the plural annulus air inlets 14.

Further, in one or more exemplary embodiments of the present invention, the bottom of the cylinder 10 is an inverted cone structure.

Further, in one or more exemplary embodiments of the present invention, the gas distributor 31 is a volute structure, and the hot air enters the gas distributor 31 in a tangential direction.

Further, in one or more exemplary embodiments of the present invention, the bottom of the cylinder 10 includes an annular baffle 13, and the annular baffle 13 forms an annular air inlet 12 with the bottom surface of the cylinder 10.

Further, in one or more exemplary embodiments of the present invention, the end of the paddle 22 is provided with a scraper 221. Preferably, the shape of the paddles 22 and the scrapers 221 is adapted to the shape of the barrel 10.

Illustratively, the number of the dispersers 21 may be one or more, preferably 1 to 5. Exemplarily, the disperser 21 may be a pressure disperser or a rotary disperser, e.g. a rotary disperser in the form of a disk or a cone. It should be understood that the number and form of the dispersers can be selected according to actual needs, and the invention is not limited thereto. Preferably, the disperser 21 is axially spaced from the paddles 22.

Illustratively, the rotating shaft 20 is driven by a shaft driving device 24, which in turn drives the disperser 21 and the stirring paddle 22 to rotate. A shaft seal 23 is provided between the rotary shaft 20 and the bottom of the cylinder 10. The rotating shaft 20 may be connected to an external feeding line through a rotary joint 25, but the present invention is not limited thereto.

The operation of the spin flash dryer according to one or more exemplary embodiments of the present invention is as follows: the material enters the cylinder 10 through the rotating shaft 20, is atomized by the disperser 21 and then is subjected to first spray drying by hot air in the cylinder 10 to form a semi-dry particle gas-solid two-phase air flow; the material after the first spray drying collides with the rotating radial gas-solid two-phase gas flow entering the gas redistributor 32 to form a highly turbulent impact area for strengthening mass and heat transfer, and the second impact flow drying is carried out; the material dried by the second impinging stream rises along with the airflow and is separated by the classifier 40, the smaller particles are discharged through the product outlet 11, the larger particles which can not pass through the classifier 40 enter the collecting cavity 50, are mixed with the hot air through the venturi mixer 60 and then enter the cylinder 10 again through the gas redistributor 32, and the rotating radial gas-solid two-phase airflow is formed to collide with the material dried by the first spray. The other part of larger particles which can not rise with the airflow directly fall down, and under the action of the stirring paddle 22 and the airflow in high-speed rotation motion, the third-time spin flash drying is carried out, and the particle group which floats and rises in a rotating mode is formed and then enters the classifier 40 for separation. The material is subjected to three different drying processes of spray drying, impinging stream drying and spin flash drying, so that product particles with certain particle size and water content are obtained.

In one or more exemplary embodiments of the present invention, the hot air may be divided into two branches, one branch entering the drum 10 through the gas distributor 31 via the gas inlet 12; the other branch is used as the main flow of the venturi mixer 60, and after the larger particles separated from the classifier 40 are sucked from the collecting cavity 50 and mixed with the larger particles, the larger particles form a rotating radial gas-solid two-phase airflow through the annular air inlet 14 by the gas redistributor 32, and the rotating radial gas-solid two-phase airflow enters the cylinder 10 and collides with the gas-solid two-phase airflow of the semi-dry particles atomized by the disperser 21. These two air streams merge within the cartridge 10 and are finally discharged from the product outlet 11.

The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. It is not intended to limit the invention to the precise form disclosed, and obviously many modifications and variations are possible in light of the above teaching. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and its practical application to enable one skilled in the art to make and use various exemplary embodiments of the invention and various alternatives and modifications as are suited to the particular use contemplated. Any simple modifications, equivalent changes and modifications made to the above exemplary embodiments shall fall within the scope of the present invention.

Claims

1. A spin flash dryer, comprising:

the cylinder body is of a cylindrical structure and sequentially comprises a rotary drying section, an impact drying section and a grading section from bottom to top, a product outlet is formed in the upper part of the cylinder body, and an air inlet is formed in the lower part of the cylinder body;

a classifier disposed within the barrel below the product outlet;

the rotating shaft coaxially penetrates through the bottom of the cylinder body, the rotating shaft is a hollow shaft, and materials enter the cylinder body through the rotating shaft;

at least one disperser coaxially communicated outside the rotating shaft for dispersing the material;

at least one layer of stirring paddle which is coaxially connected outside the rotating shaft; and

the gas distributor is arranged at the lower part of the cylinder in a surrounding manner, the outer side of the gas distributor is communicated with hot air, and the inner side of the gas distributor is communicated with the gas inlet of the cylinder.

2. The spin flash dryer of claim 1, further comprising:

the collecting cavity surrounds the outside of the cylinder below the classifier and is communicated with the inside of the cylinder through an annular air outlet;

a venturi mixer having a primary flow inlet in communication with the heated air and a secondary flow inlet in communication with the collection chamber; and

the gas redistributor is arranged outside the cylinder in a surrounding mode and located above the gas distributor, the outer side of the gas redistributor is communicated with the outlet of the Venturi mixer, and the inner side of the gas redistributor is communicated with the inside of the cylinder through an annular air inlet.

3. The spin flash dryer of claim 2, wherein the annulus intake is positioned in correspondence with the disperser.

4. The spin flash dryer of claim 2, wherein the gas redistributor is a volute structure, the heated air entering the gas redistributor tangentially.

5. A spin flash dryer according to claim 1, wherein the bottom of the drum is of inverted cone construction.

6. A spin flash dryer according to claim 1, wherein the gas distributor is a volute structure, the hot air entering the gas distributor tangentially.

7. A spin flash dryer according to claim 6, wherein the bottom of the drum comprises an annular baffle forming the air inlet with the bottom surface of the drum, the air inlet being annular.

8. A spin flash dryer according to claim 1, wherein the ends of the paddles are provided with scrapers.

9. A rotary flash dryer according to claim 1 wherein the disperser is a pressure disperser or a rotary disperser.

10. A spin flash dryer according to claim 9, wherein the rotary disperser is disk-shaped or conical.

11. A spin flash dryer according to claim 1, wherein the disperser is axially spaced from the paddle.