Air distribution plate structure and fluidized bed

Abstract

The invention provides an air distribution plate structure and a fluidized bed, and belongs to the technical field of material drying, the air distribution plate structure comprises a flange body, a plurality of groups of parallel first mesh wires distributed at intervals and a plurality of groups of parallel second mesh wires, the flange body is axially provided with a vent hole in a penetrating manner, the vent hole is provided with an air inlet end and an air outlet end, the first mesh wires are fixedly arranged on the flange body, and the second mesh wires are fixedly arranged on the flange body. The first net wires are used for covering the ventilation holes, the widths of the first net wires change from small to large in the direction from the air inlet end to the air outlet end so that air channels enabling materials to obtain the initial fluidization speed can be formed between the adjacent first net wires, the second net wires are fixedly arranged on the flange body, and the second net wires and the first net wires are arranged in a crossed mode so as to support the first net wires. The online cleaning device not only can perform online cleaning, but also has the characteristics of small wind resistance and high hot air utilization rate.

Description

Technical Field

[0001] The invention relates to the technical field of material drying, and in particular to an air distribution plate structure and a fluidized bed. Background Art

[0002] As an efficient gas-solid contact reaction device, the main function of the fluidized bed is to achieve uniform drying of materials by precisely controlling the fluid dynamics state. In this equipment, the air distributor is the core component of air flow distribution. Its structural design directly determines the flow field uniformity and fluidization stability, which in turn affects the drying efficiency and energy economy.

[0003] The current mainstream air distribution plate adopts a double-layer composite mesh structure, which specifically includes an upper mat-type woven mesh and a lower perforated support mesh. The fine mesh of the upper mat-type woven mesh can prevent the leakage of powder materials, and the lower rigid perforated support mesh can provide mechanical support. In the working state, the hot air blows through the perforated support mesh and the mat-type woven mesh in turn to obtain a higher flow rate, so that the material inside the fluidized bed obtains the initial fluidization speed, the material is dispersed and tumbled in the fluidized bed, and the hot air takes away the moisture in the material, and finally the material is dried.

[0004] However, engineering practice has found that this type of air distributor has some technical defects. Specifically, during the drying process, the material will penetrate into the assembly gap of the double-layer mesh plate under the action of pressure difference, causing pore blockage, leading to local flow field distortion and increased drag coefficient, forcing the system to increase the fan power to maintain fluidization. In addition, the double-layer mesh plate usually adopts the traditional bolt crimping assembly method, which needs to be completely disassembled for mesh cleaning. The single maintenance time is long, and repeated disassembly and assembly can easily cause deformation of the mat-type woven mesh. Summary of the invention

[0005] Based on this, the purpose of the present invention is to provide an air distribution plate structure and a fluidized bed, which can not only perform online cleaning, but also have the characteristics of small wind resistance and high hot air utilization rate.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0007] In the first aspect, the present invention provides an air distribution plate structure, comprising a flange body, a plurality of groups of parallel and spaced first meshes, and a plurality of groups of spaced second meshes, wherein the flange body is provided with ventilation holes along the axial direction, and the ventilation holes have an air inlet end and an air outlet end, the first mesh is fixed on the flange body to cover the ventilation holes, the width of the first mesh varies from small to large along the direction from the air inlet end to the air outlet end to form an air duct between adjacent first meshes so that the material obtains an initial fluidization velocity, the second mesh is fixed on the flange body, and the second mesh is cross-arranged with the first mesh to support the first mesh.

[0008] In addition, the above-mentioned air distribution plate structure according to the present invention may also have the following additional technical features:

[0009] Furthermore, the cross-sectional profile of the first mesh in the width direction is a triangle.

[0010] Furthermore, the angle between the bottom edge and the hypotenuse of the first mesh is 69 degrees to 71 degrees.

[0011] Furthermore, the cross-sectional profile of the second mesh in the width direction is a rectangle.

[0012] Furthermore, the ratio of the thickness to the width of the second mesh is 1-2.

[0013] Furthermore, the ratio of the distance between adjacent second mesh wires to the width of the second mesh wires is 10-15.

[0014] Furthermore, the ratio of the width of the second mesh to the bottom width of the first mesh is 2-3.

[0015] Furthermore, the total area of ​​the gaps formed between all adjacent first meshes accounts for 10% to 15% of the ventilation area of ​​the ventilation hole.

[0016] Furthermore, the length direction of the second mesh is perpendicular to the length direction of the first mesh.

[0017] In a second aspect, the present invention further provides a fluidized bed, comprising a hot air system, a material bin and the aforementioned air distribution plate structure, wherein the material bin is connected to the hot air system, and the air distribution plate structure is arranged on the material bin.

[0018] The beneficial effects of the present invention include at least: through the design of the structure and geometric parameters of the first mesh and the second mesh, the first mesh whose width changes from small to large along the direction from the air inlet end to the air outlet end is not easy to retain material, thereby reducing wind resistance, reducing material loss, and improving material recovery rate. Under the condition of achieving the same drying effect, there is no need to introduce a large amount of hot air, thereby improving the utilization rate of hot air and reducing energy consumption; the airway formed between adjacent first meshes, whose width changes from small to large along the direction from the air inlet end to the air outlet end, can accelerate the hot air, and there is no need to introduce hot air with a large flow rate, so that the material can obtain the airway with the initial fluidization velocity required by the process, thereby reducing energy consumption; when cleaning the first mesh, the cleaning liquid is sprayed from the air inlet end through the cleaning ball, and the inner surface of the airway with a cross-sectional width ranging from large to small can be exposed to the spray range of the cleaning liquid, so that no cleaning dead angle will be generated, and it can be cleaned without manual intervention, thereby realizing the function of online cleaning. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1is a schematic diagram of the three-dimensional structure of the air distribution plate structure in the embodiment of the present invention from a first viewing angle;

[0020] Figure 2 is a schematic diagram of the three-dimensional structure of the air distribution plate structure in the embodiment of the present invention from a second viewing angle;

[0021] Figure 3 is a schematic structural diagram of a first mesh in an embodiment of the present invention;

[0022] Figure 4 is a schematic structural diagram of a second mesh in an embodiment of the present invention;

[0023] Figure 5 Schematic diagram of the structure of the fluidized bed in an embodiment of the present invention;

[0024] Figure 6 It is a structural schematic diagram of a material bin in an embodiment of the present invention;

[0025] Description of main component symbols:

[0026] Flange body 100, ventilation hole 110, first mesh wire 200, second mesh wire 300, material bin 400;

[0027] The following specific implementation manner will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0028] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. Several embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive.

[0029] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0031] Please refer to Figures 1 to 4, is a wind distribution plate structure provided by the present invention, comprising a flange body 100, a plurality of groups of parallel and spaced first meshes 200, and a plurality of groups of spaced second meshes 300. The flange body 100 is provided with ventilation holes 110 along the axial direction, and the upper and lower sides of the ventilation holes 110 respectively form an air inlet end and an air outlet end. The first mesh 200 is fixed on the flange body 100. During assembly, the first mesh 200 can be installed on the flange body 100 by welding or by fasteners, so as to achieve the purpose of covering the ventilation holes 110 and play a role in carrying materials. Optionally, the assembly surface of the first mesh 200 can be set flush with the end face of the air inlet end, or it can be installed in the ventilation hole 110 to be spaced from the end face of the air inlet end. In order to reduce wind resistance and form an airway between adjacent first meshes 200 so that the material obtains the initial velocity of fluidization, the width of the first mesh 200 changes from small to large along the direction from the air inlet end to the air outlet end. The second mesh wire 300 is fixed on the flange body 100 and is located below the first mesh wire 200. During assembly, the second mesh wire 300 can be installed on the flange body 100 by welding or by fasteners. The second mesh wire 300 is arranged crosswise with the first mesh wire 200 to support the first mesh wire 200, increase the material carrying capacity of the first mesh wire 200, and keep the gaps between adjacent first mesh wires 200 uniform, thereby preventing the first mesh wire 200 from leaking materials due to the increase in the gap.

[0032] In this embodiment, since there are small gaps between the first meshes 200, the material will not leak out from the gaps. In addition, the width section of the first mesh 200 is set from small to large along the direction from the air inlet end to the air outlet end. When the hot air passes through the gaps between the adjacent first meshes 200, the airway with a cross-sectional width from large to small can guide the hot air, so that the hot air flow rate gradually increases, so that the hot air will obtain a higher flow rate after passing through the first mesh 200, so that the material obtains initial fluidization kinetic energy. Under the action of the hot air, the moisture in the material is evaporated, and the moisture can be drawn away to achieve the drying of the material. When cleaning, the cleaning liquid is sprayed from the air inlet end through the cleaning ball, and the inner surface of the airway with a cross-sectional width from large to small can be exposed to the spray range of the cleaning liquid, so that there will be no cleaning dead corners, and it can be cleaned without manual intervention.

[0033] In some optional embodiments, such as Figure 3 As shown, the cross-sectional profile of the first mesh 200 in the width direction is a triangle. The flat hypotenuse S2 of the triangle generates less wind resistance when guiding the hot air, which can reduce the energy loss of the hot air and ensure that the hot air can obtain a higher flow rate after passing through the first mesh 200.

[0034] In order to ensure the structural strength of the first mesh 200 while making the airway have a stronger airflow regulation ability and avoid a large resistance of the airway, in some optional embodiments, the angle between the bottom edge S1 and the hypotenuse S2 of the first mesh 200 is set to 69 degrees to 71 degrees.

[0035] In some optional embodiments, such as Figure 4 As shown, the cross-sectional profile of the second mesh 300 in the width direction is a rectangle.

[0036] Since the second mesh 300 will produce a certain wind resistance to the hot air and affect the initial fluidization kinetic energy of the material, the width of the second mesh 300 needs to be set as small as possible, but at the same time, it is necessary to ensure that the second mesh 300 has a certain structural strength. For this reason, in some optional embodiments, the ratio of the thickness H2 of the second mesh 300 to the width W2 of the second mesh 300 is set to 1-2.

[0037] Since the number of second meshes 300 will affect the amount of hot air passing through the first mesh 200, specifically, the more the second meshes 300 are, the larger the area blocking the air intake of the first mesh 200 will be, which will easily lead to insufficient initial fluidization kinetic energy of the material. For this reason, in some optional embodiments, the ratio of the distance L2 between adjacent second meshes 300 to the width W2 of the second mesh 300 is set to 10-15.

[0038] In order to ensure that the second mesh 300 has a strong structural strength and make the total area of ​​the gap formed by the first mesh 200 as large as possible, in some optional embodiments, the ratio of the width W2 of the second mesh 300 to the width W1 of the bottom edge S1 of the first mesh 200 is set to 2-3.

[0039] In order to make the total area of ​​the gaps formed by the first mesh 200 as large as possible, so that the bed pressure drop is smaller, the air intake can be increased, and thus the drying efficiency is improved. In some optional embodiments, the total area of ​​the gaps formed between all adjacent first meshes 200 accounts for 10% to 15% of the ventilation area of ​​the ventilation hole 110.

[0040] In some optional embodiments, such as Figure 2 As shown, the length direction of the second mesh 300 is perpendicular to the length direction of the first mesh 200. In this embodiment, the first mesh 200 and the second mesh 300 are perpendicularly crossed to form a stable support frame, improve the ability to carry materials, and prevent structural deformation.

[0041] Please refer to Figure 5 , Figure 6, is a fluidized bed provided by the present invention, comprising a hot air system, a material bin 400 and the aforementioned air distributor structure, wherein the material bin 400 is connected to the hot air system, and the air distributor structure is arranged on the material bin. In this embodiment, the hot air will obtain a higher flow rate after passing through the first mesh wire 200, so that the material obtains initial fluidization kinetic energy, and then the material is fluidized and tumbled in the material bin 400, and under the action of the hot air introduced by the hot air system, the moisture evaporates from the material, and then is sucked away by the exhaust fan, and finally the drying process of the material is realized.

[0042] The present invention is further described below with reference to a specific embodiment, wherein the particle size of the material to be dried is 20-80 meshes, i.e., 0.18 mm-0.83 mm, and the gap width L1 between adjacent first mesh wires 200 needs to be less than 0.18 mm:

[0043] Example 1

[0044] The gap width L1 between adjacent first meshes 200 is 0.12 mm, the ratio of the total gap area formed between all adjacent first meshes 200 to the ventilation area of ​​the ventilation hole 110 is set to 15:100, the width W1 of the bottom side S1 of the first mesh 200 is 1 mm, the height H1 between the bottom side S1 of the first mesh 200 and the hypotenuse S2 is 2 mm, the ratio of the thickness H2 of the second mesh 300 to the width W2 of the second mesh 300 is 1 to 2, the ratio of the distance L2 between adjacent second meshes 300 to the width W2 of the second mesh 300 is 5 to 10, and the ratio of the width W2 of the second mesh 300 to the width W1 of the bottom side S1 of the first mesh 200 is 2 to 3.

[0045] The material drying test was carried out in the fluidized bed using the air distribution plate structure. The maltodextrin wet particles with a particle size distribution of 20-80 mesh were used for drying. The moisture content of the maltodextrin wet particles was 20%. When the fluidized bed was working, hot air entered the material chamber from the distribution chamber at the lower end of the fluidized bed through the air distribution plate structure. The inlet air temperature was 70°C and the air volume was 2000m 3 / h, the material temperature fluctuates around 45°C in the constant speed drying stage, the drying time is about 35 minutes, the bed pressure drop is always maintained at 2000Pa during the drying process, the moisture content of the maltodextrin wet particles after the material is dried is 2.5%, the material yield is 99%, the vacuum discharging time is 6 minutes, the material is discharged cleanly, and there is no adhesion on the first mesh 200.

[0046] Example 2

[0047] The gap width L1 between adjacent first meshes 200 is 0.10 mm, the ratio of the total gap area formed between all adjacent first meshes 200 to the ventilation area of ​​the ventilation hole 110 is set to 13:100, the width W1 of the bottom side S1 of the first mesh 200 is 1 mm, the height H1 between the bottom side S1 of the first mesh 200 and the hypotenuse S2 is 2 mm, the ratio of the thickness H2 of the second mesh 300 to the width W2 of the second mesh 300 is 1 to 2, the ratio of the distance L2 between adjacent second meshes 300 to the width W2 of the second mesh 300 is 5 to 10, and the ratio of the width W2 of the second mesh 300 to the width W1 of the bottom side S1 of the first mesh 200 is 2 to 3.

[0048] The material drying test was carried out in the fluidized bed using the air distribution plate structure. The maltodextrin wet particles with a particle size distribution of 20-80 mesh were used for drying. The moisture content of the maltodextrin wet particles was 20%. When the fluidized bed was working, hot air entered the material chamber from the distribution chamber at the lower end of the fluidized bed through the air distribution plate structure. The inlet air temperature was 70°C and the air volume was 2000m 3 / h, the material temperature fluctuates around 45°C in the constant speed drying stage, the drying time is about 40 minutes, the bed pressure drop is always maintained at 2600Pa during the drying process, the moisture content of the maltodextrin wet particles after the material is dried is 2.5%, the material yield is 99%, the vacuum discharging time is 6 minutes, the material is discharged cleanly, and there is no adhesion on the first mesh 200.

[0049] Example 3

[0050] The gap width L1 between adjacent first meshes 200 is 0.12 mm, the ratio of the total gap area formed between all adjacent first meshes 200 to the ventilation area of ​​the ventilation hole 110 is set to 11:100, the width W1 of the bottom side S1 of the first mesh 200 is 1.5 mm, the height H1 between the bottom side S1 of the first mesh 200 and the hypotenuse S2 is 3 mm, the ratio of the thickness H2 of the second mesh 300 to the width W2 of the second mesh 300 is 1 to 2, the ratio of the distance L2 between adjacent second meshes 300 to the width W2 of the second mesh 300 is 5 to 10, and the ratio of the width W2 of the second mesh 300 to the width W1 of the bottom side S1 of the first mesh 200 is 2 to 3.

[0051] The material drying test was carried out in the fluidized bed using the air distribution plate structure. The maltodextrin wet particles with a particle size distribution of 20-80 mesh were used for drying. The moisture content of the maltodextrin wet particles was 20%. When the fluidized bed was working, hot air entered the material chamber from the distribution chamber at the lower end of the fluidized bed through the air distribution plate structure. The inlet air temperature was 70°C and the air volume was 2000m 3 / h, the material temperature fluctuates around 45°C in the constant speed drying stage, the drying time is about 45 minutes, the bed pressure drop is always maintained at 3000Pa during the drying process, the moisture content of the maltodextrin wet particles after the material is dried is 2.5%, the material yield is 99%, the vacuum discharging time is 6 minutes, the material is discharged cleanly, and there is no adhesion on the first mesh 200.

[0052] Comparative Example 1

[0053] The material drying test was carried out in the fluidized bed using a double-layer composite mesh structure. The maltodextrin wet particles with a particle size distribution of 20-80 mesh were used for drying. The moisture content of the maltodextrin wet particles was 20%. When the fluidized bed was working, hot air entered the material chamber from the distribution chamber at the lower end of the fluidized bed through the double-layer composite mesh structure. The inlet air temperature was 70°C and the air volume was 2400m 3 / h, the material temperature fluctuates around 45°C in the constant speed drying stage, the drying time is about 45 minutes, the bed pressure drop is always maintained at 2800Pa during the drying process, the moisture content of maltodextrin wet particles is 2.5% after the material is dried, the material yield is 98%, the vacuum discharge time is 8 minutes, there is material residue, and there is material adhesion on the double-layer composite mesh structure, which is difficult to clean.

[0054] In summary, no material will remain in the air distribution plate structure in the present application, thereby reducing material loss and improving material recovery rate. At the same time, the wind resistance of the air distribution plate structure is also reduced. When obtaining the same drying effect, a larger hot air volume is not required, which improves the utilization rate of hot air and reduces energy consumption.

[0055] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0056] The above-mentioned embodiments only express several implementation modes of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the protection scope of the present invention. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the attached claims.

Claims

1. A wind distribution plate structure, characterized in that: The air distribution plate structure comprises: The flange body is provided with a ventilation hole extending through the flange body in the axial direction, wherein the ventilation hole has an air inlet end and an air outlet end; A plurality of groups of first meshes which are parallel and spaced apart are fixed on the flange body and used to cover the ventilation holes, wherein the width of the first meshes varies from small to large along the direction from the air inlet end to the air outlet end, so as to form an air passage between adjacent first meshes to enable the material to obtain an initial fluidization velocity; A plurality of groups of second mesh wires are arranged at intervals and fixed on the flange body. The second mesh wires are arranged crosswise with the first mesh wires to support the first mesh wires.

2. The air distribution plate structure according to claim 1, characterized in that: The cross-sectional profile of the first mesh in the width direction is a triangle.

3. The air distribution plate structure according to claim 2, characterized in that: The angle between the bottom edge and the hypotenuse of the first mesh is 69 degrees to 71 degrees.

4. The air distribution plate structure according to claim 2 or 3, characterized in that: The cross-sectional profile of the second mesh in the width direction is a rectangle.

5. The air distribution plate structure according to claim 4, characterized in that: The ratio of the thickness to the width of the second mesh is 1-2.

6. The air distribution plate structure according to claim 4, characterized in that: The ratio of the distance between adjacent second mesh wires to the width of the second mesh wire is 10-15.

7. The air distribution plate structure according to claim 4, characterized in that: The ratio of the width of the second mesh to the bottom width of the first mesh is 2-3.

8. The air distribution plate structure according to claim 1, characterized in that: The ratio of the total area of ​​the gaps formed between all adjacent first meshes to the ventilation area of ​​the ventilation hole is 10% to 15%.

9. The air distribution plate structure according to claim 1, characterized in that: The length direction of the second mesh is perpendicular to the length direction of the first mesh.

10. A fluidized bed, characterized in that: It comprises a hot air system, a material bin and an air distribution plate structure as described in any one of claims 1 to 9, wherein the material bin is connected to the hot air system, and the air distribution plate structure is arranged on the material bin.

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