Gas distribution device for adsorbing VOCs (volatile organic compounds) in industrial waste gas

Abstract

The utility model discloses a gas distribution device for adsorbing VOCs (Volatile Organic Compounds) in industrial waste gas, which comprises at least one gas distribution unit arranged in a conical diffusion pipeline below a waste gas main pipeline, the gas distribution unit is of a conical cylinder structure with two open ends; and when a plurality of gas distribution units are arranged, the gas distribution units are sequentially sleeved from inside to outside. According to the structural design, a flow field and a pressure field of gas can be distributed more uniformly, and the resistance is small and is only 30-50 Pa; the gas distribution device is simple in structure, easy to maintain and easy to popularize and apply in industrial VOCs waste gas treatment; all the gas distribution units are arranged in the gas flow direction and have the advantages of being high in flow field and pressure field distribution uniformity, low in pressure loss, low in abrasion degree, free of flow dead zones and not prone to blockage, and the waste gas treatment amount is increased.

Description

Technical Field

[0001] The utility model relates to the technical field of industrial VOCs-containing waste gas treatment equipment, in particular to a gas distribution device for adsorbing VOCs in industrial waste gas. Background Art

[0002] Industrial production is the main source of VOCs. Currently, most VOCs waste gas treatment processes use adsorption methods. Specifically, the organic components in the waste gas are adsorbed or absorbed on the surface of the adsorbent using the micropores or chemical substances of the adsorbent, thereby achieving the purpose of waste gas VOCs treatment.

[0003] The pressure of the exhaust gas is relatively uniform when it flows in the exhaust gas main pipe before entering the adsorption equipment. However, before entering the adsorption layer in the adsorption equipment, the gas must pass through a 90° bend pipe and then enter a tapered diffuser. When the exhaust gas passes through the diffuser, the flow rate increases from the inside to the outside, such as Figure 1 As shown in , the pressure decreases to form a pressure gradient, which causes the flow field of the gas adsorption device to change. Figure 2 The figure shows the velocity field simulation results of a typical waste gas adsorption process. The adsorption system consists of a waste gas main pipeline, two adsorption boxes and a waste gas outlet pipe. Activated carbon is used as the adsorption material. The processing capacity of each adsorption box is 20,000 m 3 / h. According to the velocity field simulation results, the velocity field distribution inside the diffusion tube before the exhaust gas enters the activated carbon from the exhaust main pipe is uneven, and the flow rate and pressure distribution of the exhaust gas on the adsorbent surface are uneven, even forming eddies or "dead zones" inside the VOCs adsorption equipment, affecting the adsorbent's treatment efficiency.

[0004] Therefore, in order to prevent the exhaust gas from forming a "flow dead zone" in the conical diffuser and improve the gas distribution effect in the adsorbent bed, those skilled in the art have proposed installing a gas distribution device between the exhaust gas main pipeline and the adsorbent bed. Currently, the most commonly used are louvered gas distributors, guide plates, and gas distribution plates:

[0005] The leaf-window type gas distributor has a poor effect on airflow distribution, and the blades are difficult to repair and replace, which affects the uniformity of gas distribution. At the same time, liquid particles condensed from exhaust gas are very easy to adhere to the blades;

[0006] The guide plate is a plurality of arc-shaped guide blades arranged in the flue. The resistance of this blade is generally relatively small. The gas is very likely to form a large vortex on the back of the guide blade, causing a dead bed and affecting the uniformity of gas distribution.

[0007] The gas distribution plate has a good effect on gas distribution, but it has a complex structure and large resistance. It is easy to form small vortices, which form a dead bed on the surface of the distribution plate. The liquid particles condensed from the exhaust gas can easily accumulate behind the distribution plate holes and block the gas channel, and it is difficult to maintain. SUMMARY

[0008] Therefore, the industrial waste gas VOCs adsorption gas distribution device is provided to solve the technical problem of poor flow rate and pressure distribution effect of the current gas distribution device.

[0009] The following presents a simplified summary of some aspects of the disclosed embodiments in order to provide a basic understanding of such embodiments. This summary is not an extensive overview of the embodiments and is intended neither to identify key / critical elements of these embodiments nor to delineate the scope of the embodiments. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is presented later.

[0010] The utility model adopts the following technical scheme:

[0011] The industrial waste gas VOCs adsorption gas distribution device comprises at least one gas distribution unit, and the gas distribution unit is arranged in a conical diffusion pipeline below a waste gas main pipeline.

[0012] The gas distribution unit is a conical cylinder structure with open ends.

[0013] When the gas distribution unit is multiple, each gas distribution unit is sequentially sleeved from inside to outside, and the gas inlet and the gas outlet of each gas distribution unit are located in the same plane with the gas inlet end and the gas outlet end of the conical diffusion pipeline.

[0014] Further, when the gas distribution unit is multiple, the cone angle of each gas distribution unit increases from inside to outside, and the area of the gas inlet and the gas outlet of each gas distribution unit increases from inside to outside.

[0015] Further, when the waste gas main pipeline enters the conical diffusion pipeline along a straight pipeline, the center line of each gas distribution unit is located on the center line of the conical diffusion pipeline; when the waste gas main pipeline enters the conical diffusion pipeline along a 90° elbow pipeline, the upper and lower bottom center lines of each gas distribution unit are located on the outer side of the center line of the conical diffusion pipeline, and the upper and lower bottom center lines of each gas distribution unit sequentially move away from the center line of the conical diffusion pipeline from inside to outside.

[0016] Further, when the waste gas amount is 5000m 3 / h, one gas distribution unit is arranged in the conical diffusion pipeline; when the waste gas amount is 5000m 3 / h-20000m 3 / h, two gas distribution units are arranged in the conical diffusion pipeline; when the waste gas amount is 20000m 3 / h-100000m 3when the waste gas quantity is 100000m 3 when the waste gas quantity is 100000m

[0017] Further, the thickness of the gas distribution unit is 1mm-3mm.

[0018] Further, the material of the gas distribution unit is the same as the material of the adsorption equipment shell.

[0019] Further, each gas distribution unit is welded in the conical diffusion pipeline.

[0020] The beneficial effects brought by the utility model are:

[0021] 1. Compared with the existing louvered gas distributor, guide plate and gas distribution plate, the structural design of the application can make the flow field and pressure field distribution of the gas more uniform, and the resistance is small, only 30-50Pa.

[0022] 2. The gas distribution device of the application is simple in structure, easy to maintain and easy to popularize and apply in industrial VOCs waste gas treatment.

[0023] 3. Each gas distribution unit has the characteristics of high uniformity of flow field and pressure field distribution, low pressure loss, low wear degree, no flow dead zone and not easy to block along the gas flow direction, and the waste gas treatment capacity is improved. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical scheme in the embodiments of the utility model or the prior art, the drawings needed to be used in the embodiment or the prior art description will be briefly introduced below, and obviously, the drawings in the following description are only some embodiments of the utility model, and those skilled in the art can obtain other drawings according to these drawings without creating creative labor.

[0025] Figure 1 is the velocity field simulation result graph of the typical waste gas adsorption process when there is no gas distribution device;

[0026] Figure 2 is the pressure field simulation result graph of the typical waste gas adsorption process when there is no gas distribution device;

[0027] Figure 3 is the assembly schematic view of the industrial waste gas VOCs adsorption gas distribution device, waste gas main pipeline and adsorption equipment of the utility model;

[0028] Figure 4 is the position schematic view of the industrial waste gas VOCs adsorption gas distribution device in the conical diffusion pipeline of the utility model;

[0029] Figure 5 is the position diagram of the air inlet of each gas distribution unit of the utility model and the air inlet end of the conical diffusion pipeline, wherein the outermost rectangle is the upper end surface size of the conical diffusion pipeline;

[0030] Figure 6 is the position diagram of the air outlet of each gas distribution unit of the utility model and the air outlet end of the conical diffusion pipeline, wherein the outermost rectangle is the lower end surface size of the conical diffusion pipeline;

[0031] Figure 7 is the velocity distribution diagram of the gas distribution device of the utility model adopted in the application example, measured along the direction of the waste gas main pipeline;

[0032] Figure 8 is the velocity distribution diagram of the gas distribution device of the utility model adopted in the application example, measured perpendicular to the direction of the waste gas main pipeline. DETAILED DESCRIPTION

[0033] The embodiments of the utility model will be described in detail below with reference to the drawings. It should be clear that the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the utility model.

[0034] As Figures 3-6 shown, in some illustrative embodiments, a gas distribution device for industrial waste gas VOCs adsorption is provided, comprising at least one gas distribution unit 1, and the gas distribution unit 1 is arranged in the conical diffusion pipeline 3 below the waste gas main pipeline 2, for uniformly distributing the waste gas to the adsorption equipment 4.

[0035] Among them, the waste gas main pipeline 2 is mainly responsible for collecting industrial waste gas from different production links, and conveying it to the subsequent treatment system. The conical diffusion pipeline 3 is installed below the outlet of the waste gas main pipeline 2, diffuses the high-speed airflow from the waste gas main pipeline 2, reduces its speed and increases its area, so as to achieve the effect of uniform distribution. The conical diffusion pipeline 3 is generally conical or funnel-shaped, and its cross-sectional area gradually expands, which helps to gently reduce the airflow speed.

[0036] The gas distribution unit 1 is a conical cylinder structure with both ends open, which is similar in shape to the conical diffusion pipe 3, that is, it matches the shape of the conical diffusion pipe 3, but the size is smaller. When there is only one gas distribution unit 1, it is directly installed inside the conical diffusion pipe 3, helping to further refine the distribution of the exhaust gas. When there are multiple gas distribution units 1, that is, at least two, each gas distribution unit 1 is sequentially nested from inside to outside, forming a multi-stage diffusion structure, so that the exhaust gas is more evenly distributed when passing through these conical cylinders. The size of each gas distribution unit 1 is slightly different, and the size of the unit increases outward, which helps the gradual diffusion and smooth transition of the airflow.

[0037] The upper and lower end faces of each gas distribution unit 1 are located on the same side as the upper and lower end faces of the conical diffusion pipe 3, that is, the gas inlet 101 of each gas distribution unit 1 is located on the same plane as the gas inlet end 301 of the conical diffusion pipe 3, and the gas outlet 102 of each gas distribution unit 1 is located on the same plane as the gas outlet end 302 of the conical diffusion pipe 3.

[0038] The gas inlet end 301 is the narrower end of the conical diffusion pipe 3, which is connected to the exhaust gas main pipe 2; the gas outlet end 302 is the wider end of the conical diffusion pipe 3, which is connected to the adsorption device 4. The gas inlet 101 is the narrower end of the gas distribution unit 1, which is on the same plane as the gas inlet end 301 of the conical diffusion pipe; the gas outlet 102 is the wider end of the gas distribution unit 1, which is on the same plane as the gas outlet end 302 of the conical diffusion pipe. The above structure design can ensure that the exhaust gas entering the conical diffusion pipe 3 from the exhaust gas main pipe 2 will not encounter any obstacles, thereby maintaining the continuity of the airflow, while helping to ensure that the exhaust gas can be evenly distributed to the wider area of the conical diffusion pipe 3 after passing through the gas distribution unit 1, and finally entering the adsorption device 4. This layout ensures smooth transition of the exhaust gas from the exhaust gas main pipe 2 to the conical diffusion pipe 3 and then to the adsorption device 4, while achieving uniform distribution of the exhaust gas on the surface of the adsorption material.

[0039] When there are multiple gas distribution units 1, the cone angles of each gas distribution unit 1 increase from inside to outside, and the areas of the gas inlet and gas outlet of each gas distribution unit 1 increase from inside to outside. In this application, the cone angle refers to the angle between the side surface of the conical cylinder and the top side end surface of each gas distribution unit 1. The cone angles of each gas distribution unit 1 are different, and the cone angle of the outer unit is larger. Such design helps to control the velocity distribution of the airflow, ensuring that the exhaust gas can be more finely distributed when passing through different levels of gas distribution units. With the increase of the units, the areas of the upper and lower cone surfaces also increase sequentially. This design helps the exhaust gas to gradually expand the contact area with the increase of the units, further refining the distribution of the exhaust gas and improving the adsorption efficiency.

[0040] When the exhaust gas main pipeline 2 enters the conical diffusion pipeline 3 along the straight pipeline, the gas distribution unit 1 is a rotationally symmetric conical cylinder structure, and the center line of each gas distribution unit 1 is located on the center line of the conical diffusion pipeline 3. At this time, the center line of the gas distribution unit 1 refers to the central axis of the conical cylinder structure.

[0041] When the exhaust gas main pipeline 2 enters the conical diffusion pipeline 3 along the 90° elbow pipeline, the gas distribution unit 1 is an asymmetric conical cylinder structure, which means that the shape of the structure changes after rotating around its central axis. When the exhaust gas main pipeline 2 enters the conical diffusion pipeline 3 along the 90° elbow pipeline, the upper and lower bottom center lines of each gas distribution unit 1 are located on the outside of the center line of the conical diffusion pipeline 3, and the upper and lower bottom center lines of each gas distribution unit 1 from inside to outside are sequentially away from the center line of the conical diffusion pipeline 3. The center line of the conical diffusion pipeline 3 refers to the central axis of the conical diffusion pipeline 3; the upper and lower bottom center lines refer to the line connecting the rotationally symmetric centers of the two end faces of the conical cylinder structure.

[0042] The number of gas distribution units 1 is designed according to the size of the treated exhaust gas:

[0043] When the exhaust gas amount is 5000m 3 / h, one gas distribution unit 1 is arranged in the conical diffusion pipeline 3;

[0044] When the exhaust gas amount is 5000m 3 / h-20000m 3 / h, two gas distribution units 1 are arranged in the conical diffusion pipeline 3;

[0045] When the exhaust gas amount is 20000m 3 / h-100000m 3 / h, three gas distribution units 1 are arranged in the conical diffusion pipeline 3;

[0046] When the exhaust gas amount is 100000m 3 / h or more, at least four gas distribution units 1 are arranged in the conical diffusion pipeline 3.

[0047] When the exhaust gas amount is large, increasing the number of gas distribution units 1 can ensure that the exhaust gas can be more evenly distributed on the adsorbent bed, thereby improving the adsorption efficiency, and more gas distribution units 1 can further subdivide the gas flow, making the distribution of exhaust gas in the adsorbent bed more uniform, reducing the possibility of local supersaturation. In addition, adjusting the number of gas distribution units 1 according to the exhaust gas amount can make the system more flexible to adapt to different working conditions, ensuring that the system can operate efficiently under different conditions.

[0048] The thickness of the gas distribution unit 1 is 1-3 mm. By designing the thickness of the gas distribution unit to be 1-3 mm, the gas flow distribution efficiency of the device can be improved, the weight can be reduced, the cost can be reduced, and the processing, installation and maintenance can be facilitated, while ensuring sufficient strength and durability.

[0049] The material of the gas distribution unit 1 is the same as that of the adsorption equipment shell. Using the same material can improve the performance, reliability and economy of the entire system, and this design choice helps to ensure stable operation of the equipment under various working conditions, and reduces maintenance costs and potential safety hazards.

[0050] Each gas distribution unit 1 is welded in the conical diffusion pipe 3. Welding can ensure a firm connection between the gas distribution unit and the conical diffusion pipe, improving the structural stability of the entire device. Welding provides a strong mechanical connection, which helps to resist the effects of external vibration or internal gas flow impact.

[0051] Since the industrial VOCs-containing waste gas pipeline and the adsorption treatment equipment are mainly rectangular in actual application, the gas distribution unit of the embodiment is rectangular. By determining the number of gas distribution units and calculating the angles of each gas distribution unit, a gas distribution device with good distribution performance and small resistance is finally designed. The design and calculation process of the gas distribution device is as follows:

[0052] First, the gas flow through each gas distribution unit is:

[0053]

[0054] In the above formula, Q is the total waste gas flow; θ i is the lateral angle of the i-th gas distribution unit; is the vertical angle of the i-th gas distribution unit; N is the number of gas distribution units.

[0055] Second, the critical pressure drop of the gas through the gas flow distribution device is:

[0056]

[0057] In the above formula, ρ f is the density of the gas, and the density of air is 1.29 kg / m 3 ; U is the average velocity of the gas flow.

[0058] Third, the flow rate of the gas through the gas distribution device is:

[0059] The flow velocity of the waste gas in each gas distribution unit is related to the cross-sectional area of the bottom surface of the gas distribution device, as shown in the following formula:

[0060]

[0061] In the above formula: Q is the total exhaust gas flow; A i is the length of the upper end surface of the i-th gas distribution unit; B i is the width of the upper end surface of the i-th gas distribution unit.

[0062] The gas distribution device of the present application is arranged between the exhaust gas main pipeline and the adsorbent bed, and by changing the flow rate and pressure distribution of the gas inside the adsorbent bed, the exhaust gas and VOCs components are evenly distributed in the adsorbent bed, eliminating the dead zones formed by the gas in the equipment, improving the probability of contact between the adsorbent and the exhaust gas, and achieving the purpose of improving the adsorption efficiency of the adsorbent on VOCs. Moreover, the gas distribution device of the present application can improve the gas treatment capacity, and the structure is relatively simple, the maintenance difficulty is low, and is suitable for popularization and application in industrial VOCs exhaust gas treatment.

[0063] The following example illustrates the technical effect of the gas distribution device for industrial exhaust gas VOCs adsorption of the present application.

[0064] The present application is applied to a set of paint spraying process containing VOCs exhaust gas adsorption treatment process, and the total exhaust gas treatment capacity is designed to be 40000m 3 / h, and two sets of activated carbon adsorption equipment are arranged, and the exhaust gas treatment capacity of each adsorption equipment is 20000m 3 / h. The exhaust gas main pipeline is 800mmx800mm, the activated carbon adsorption equipment is composed of a conical diffusion pipe, an activated carbon adsorption layer and a gas collecting pipe, and the total height of the equipment is 2500mm. The size of the upper gas inlet end of the conical diffusion pipe is 600mmx600mm, the size of the lower gas outlet end is 1850mmx1850mm, and the height is 400mm; the size of the activated carbon adsorption layer is 1850mmx1850mm, and the height is 1700mm; the conical gas collecting pipe is symmetrical with the conical diffusion pipe. The exhaust gas main pipeline is arranged along the horizontal direction, and the two activated carbon adsorption equipment are arranged along the vertical direction.

[0065] The gas distribution device is arranged in the conical diffusion pipe 3, and there are two gas distribution units 1, and the size and position of each gas distribution unit 1 are respectively as shown in Figures 3-6 .

[0066] In actual application, the exhaust gas treatment capacity of each activated carbon adsorption equipment is 12900m 3 / h. The flow rate of the exhaust gas after using the gas distribution device of the present application is tested by using the hot wire method, and the test is carried out along the exhaust gas main pipeline and two horizontal lines perpendicular to the exhaust gas main pipeline, respectively, and the results are respectively as shown in Figure 7 and Figure 8The position of the 0 point of the abscissa is located on the center line of the adsorption equipment along the vertical aspect. The results show that after the gas distribution device is used, the gas is uniformly distributed in the activated carbon adsorption bed, and the gas flow rate distribution is between 0.78 m / s and 1.21 m / s.

[0067] In summary, the gas distribution device has the effect of uniformly distributing gas, eliminates channeling and dead angles, has small resistance, is convenient to maintain, is favorable for improving the full contact of the waste gas VOCs component and the adsorbent, and improves the adsorption efficiency.

[0068] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A gas distribution device for industrial exhaust VOCs adsorption, characterized by, The gas distribution unit is a conical cylinder structure with both ends open. When there are multiple gas distribution units, each gas distribution unit is sequentially sleeved from inside to outside, and the gas inlet and the gas outlet of each gas distribution unit are located in the same plane as the gas inlet end and the gas outlet end of the conical diffusion pipe. When there are multiple gas distribution units, the cone angles of each gas distribution unit gradually increase from inside to outside, and the areas of the gas inlet and the gas outlet of each gas distribution unit gradually increase from inside to outside. When the exhaust gas main pipe enters the conical diffusion pipe along a straight pipe, the center line of each gas distribution unit is located on the center line of the conical diffusion pipe. When the exhaust gas main pipe enters the conical diffusion pipe along a 90° elbow pipe, the upper and lower center lines of each gas distribution unit are located on the outside of the center line of the conical diffusion pipe, and the upper and lower center lines of each gas distribution unit gradually move away from the center line of the conical diffusion pipe from inside to outside. The thickness of the gas distribution unit is 1mm-3mm.

2. The gas distribution apparatus for industrial exhaust VOCs adsorption according to claim 1, characterized in that, When the exhaust gas amount is 5000m 3 / h, one gas distribution unit is arranged in the conical diffusion pipe; when the exhaust gas amount is 5000m 3 / h-20000m 3 / h, two gas distribution units are arranged in the conical diffusion pipe; when the exhaust gas amount is 20000m 3 / h-100000m 3 / h, three gas distribution units are arranged in the conical diffusion pipe; when the exhaust gas amount is 100000m 3 / h or above, at least four gas distribution units are arranged in the conical diffusion pipe.

3. The gas distribution apparatus for industrial exhaust VOCs adsorption according to claim 2, characterized in that, The material of the gas distribution unit is the same as that of the adsorption equipment shell.

4. The gas distribution apparatus for industrial exhaust VOCs adsorption according to claim 3, characterized in that, Each gas distribution unit is welded in the conical diffusion pipe.

5. The gas distribution apparatus of claim 4, wherein ​

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