Device for removing particulate matters and SO3 in flue gas

Abstract

The invention belongs to the technical field of flue gas purification, and particularly discloses a device for removing particulate matters and SO3 in flue gas. The device for removing particulate matters and SO3 in flue gas comprises a removal tower body, a demisting assembly and a spraying assembly. A smoke inlet is formed in the side wall of the bottom of the removal tower body, and a smoke outlet communicated with the smoke inlet is formed in the top of the removal tower body. The demisting assembly is arranged at the upper part in the removal tower body, the demisting assembly comprises a primary demister and a secondary demister which are sequentially arranged at an interval from bottom to top, the primary demister and the secondary demister are baffle plate type demisters, the blade spacing of the primary demister is A, the blade spacing of the secondary demister is B, A is 20-95 mm, B is 20-95 mm, and B is 60-70% A. A spraying head of the spraying assembly is arranged in the removal tower body and is positioned between the smoke inlet and the demisting assembly. According to the invention, the removal efficiency of particulate matters and SO3 in the flue gas can be improved.

Description

Technical Field

[0001] The invention belongs to the technical field of flue gas purification equipment, and specifically relates to a device for removing particulate matter and SO3 in flue gas. Background Art

[0002] Particulate matter and SO3 generated during coal combustion are one of the main air pollutants, which are harmful to the atmospheric environment and human health. In the coal-fired flue gas removal device in the related art, a demister is usually used to remove droplets and fine particles in the flue gas to prevent secondary pollution, protect downstream equipment, and ensure the quality of the exhaust gas. However, some demisters are not effective in removing pollutants such as particulate matter and SO3 in the flue gas. Summary of the invention

[0003] The present invention aims to solve one of the technical problems in the related art to at least a certain extent. To this end, an embodiment of the present invention provides a device for removing particulate matter and SO3 in flue gas, which can improve the removal efficiency of particulate matter and SO3 in flue gas.

[0004] The device for removing particulate matter and SO3 from flue gas of the embodiment of the present invention comprises: a removal tower body, wherein the bottom side wall of the removal tower body is provided with a smoke inlet, and the top of the removal tower body is provided with a smoke exhaust port connected to the smoke inlet; a defogger assembly, wherein the defogger assembly is arranged above the removal tower body, and the defogger assembly comprises a primary defogger and a secondary defogger which are arranged in sequence from bottom to top, and both the primary defogger and the secondary defogger are baffle type defoggers, the blade spacing of the primary defogger is A, and the blade spacing of the secondary defogger is B, A is 20 mm to 95 mm, B is 20 mm to 95 mm, and B=60% to 70% A; a spray assembly, wherein the spray head of the spray assembly is arranged in the removal tower body and is located between the smoke inlet and the defogger assembly.

[0005] In this embodiment, the flue gas enters the removal tower body from the smoke inlet of the removal tower body, and the flue gas is sprayed by the spray assembly, and then passes through the primary demister and the secondary demister in sequence, and the particulate matter and SO3 in the flue gas are synergistically removed to reduce the emission of pollutants in the flue gas. By arranging the primary demister and the secondary demister in the removal tower body, the blade spacing of the primary demister is greater than the blade spacing of the secondary demister, and the primary demister can capture larger droplets, and the secondary demister can capture smaller droplets, and by reasonably setting the blade spacing of the primary demister and the secondary demister, it is possible to minimize the obstruction to the airflow while ensuring high removal efficiency.

[0006] In this embodiment, the height between the bottom of the primary demister and the top of the secondary demister is 3.5 m to 4.5 m.

[0007] In this embodiment, the spray head includes a plurality of spray nozzles, and the plurality of spray nozzles are evenly spaced and distributed along a flow cross section of the flue gas in the removal tower body.

[0008] In this embodiment, the temperature of the spray liquid sprayed from the spray nozzle is 0°C to 20°C.

[0009] In this embodiment, the device for removing particulate matter and SO3 in flue gas further includes a packing layer, which is arranged in the removal tower body and is located below the spray head.

[0010] In this embodiment, the spray heads are provided in multiple groups, the filler layer is provided in multiple layers, and the multiple groups of spray heads and the multiple layers of filler layers are alternately arranged from bottom to top.

[0011] In this embodiment, the flow rate of the flue gas entering the removal tower body is 2.5m / s to 3.8m / s.

[0012] In this embodiment, the device for removing particulate matter and SO3 in flue gas further includes an airflow homogenizer, which is arranged at the bottom of the removal tower body to evenly distribute the flue gas entering the removal tower body.

[0013] In this embodiment, the airflow homogenizing member is annular and forms an annular cavity with the inner circumferential wall of the removal tower body. The airflow homogenizing member is provided with an inlet connected to the smoke inlet, and the inner side wall of the annular cavity is provided with a plurality of outlets evenly distributed along the circumference of the annular cavity, and the outlets are arranged to be inclined downward.

[0014] In this embodiment, the angle between the extension direction of the outlet and the side wall of the removal tower body is 20° to 45°. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic structural diagram of the device for removing particulate matter and SO3 in flue gas in an embodiment of the present invention without the airflow homogenizing component.

[0016] Figure 2 It is a partial structural schematic diagram of a device for removing particulate matter and SO3 in flue gas according to an embodiment of the present invention.

[0017] Reference numerals:

[0018] 1. Remove the tower body; 11. Smoke inlet; 12. Smoke outlet;

[0019] 2. Demisting assembly; 21. Primary demister; 22. Secondary demister;

[0020] 3. Spray assembly;

[0021] 4. Filling layer;

[0022] 5. air flow homogenizing element; 51. annular cavity; 52. outlet. DETAILED DESCRIPTION

[0023] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0024] In this embodiment, if Figure 1 As shown, the device for removing particulate matter and SO3 in flue gas includes a removal tower body 1, a demister assembly 2 and a spray assembly 3. A smoke inlet 11 is provided on the bottom side wall of the removal tower body 1, and a smoke exhaust port 12 connected to the smoke inlet 11 is provided on the top of the removal tower body 1. The demister assembly 2 is arranged above the removal tower body 1, and the demister assembly 2 includes a primary demister 21 and a secondary demister 22 which are arranged in sequence from bottom to top. Both the primary demister 21 and the secondary demister 22 are baffle demisters, and the blade spacing of the primary demister 21 is A, and the blade spacing of the secondary demister 22 is B, A is 20mm-95mm, B is 20mm-95mm, and B=60%-70%A. The spray head of the spray assembly 3 is arranged in the removal tower body 1 and is located between the smoke inlet 11 and the demister assembly 2.

[0025] Specifically, since the blade spacing A of the first-stage demister 21 is 20mm to 95mm, the blade spacing B of the second-stage demister 22 is 20mm to 95mm, and B = 60% to 70% A, when B takes the minimum value of 20mm, the value of A can be 28.6mm to 33.3mm, and when A takes the maximum value of 95mm, B is 57mm to 66.5mm. From the above, it can be seen that the minimum value of A is 28.6mm and the maximum value of B is 66.5mm. That is, the blade spacing A of the first-stage demister 21 can be within the range of 28.6mm to 95mm, and the value of B can be adjusted according to the value of A. The specific values ​​of A and B are not limited here. In addition, the structure of the blades of the first-stage demister 21 and the blades of the second-stage demister 22 is conventional prior art and will not be described in detail here.

[0026] For example, the blades of the primary demister 21 and the secondary demister 22 can be made of PP (polypropylene), which has excellent acid and alkali resistance and can effectively prevent corrosion from the corrosiveness in the flue gas, thereby extending the service life of the demister. In addition, the PP material is light in weight, which makes installation and maintenance more convenient, reduces the requirements for the supporting structure, and reduces the overall load of the equipment.

[0027] In this embodiment, the flue gas enters the removal tower body 1 from the smoke inlet 11 of the removal tower body 1, and the flue gas is sprayed by the spray assembly 3, and then passes through the primary demister 21 and the secondary demister 22 in sequence, and the particulate matter and SO3 in the flue gas are synergistically removed to reduce the emission of pollutants in the flue gas. By arranging the primary demister 21 and the secondary demister 22 in the removal tower body 1, the blade spacing of the primary demister 21 is greater than the blade spacing of the secondary demister 22, and larger droplets can be captured by the primary demister 21, and smaller droplets can be captured by the secondary demister 22, and by reasonably setting the blade spacing of the primary demister 21 and the secondary demister 22, it is possible to minimize the obstruction to the airflow while ensuring high removal efficiency.

[0028] In this embodiment, the height H between the bottom of the primary demister 21 and the top of the secondary demister 22 is 3.5 m to 4.5 m.

[0029] For example, H can be 3.5m, 3.7m, 4m, 4.2m or 4.5m, etc. If H is too large, the space occupied by the defogger assembly 2 is large, which increases the construction and maintenance costs and the occupied site. In addition, the spacing between the primary defogger 21 and the secondary defogger 22 is too large, and the airflow may form a short circuit between the primary defogger 21 and the secondary defogger 22, so that the primary defogger 21 cannot remove larger droplets, and more droplets enter the secondary defogger 22, which increases the burden of the secondary defogger 22 and affects the defog effect. If H is too small, the airflow will encounter greater resistance when passing through, which will cause the pressure drop in the system to increase, and power equipment such as fans will need to consume more energy to maintain normal operation, which increases energy consumption and operating costs. It will also cause the droplets captured by the primary defogger 21 to be re-involved in the airflow under the disturbance of the airflow, and fail to settle to the bottom of the tower in time, which increases the processing burden of the secondary defogger 22 and reduces the overall defog efficiency.

[0030] In this embodiment, by setting the height H between the bottom of the first-stage demister 21 and the top of the second-stage demister 22 to 3.5m to 4.5m, the distance between the first-stage demister 21 and the second-stage demister 22 is maintained at a reasonable distance, which is beneficial to improving the removal efficiency, making the removal device operate efficiently, fully reducing energy consumption, and making full use of space.

[0031] In this embodiment, if Figure 1 As shown, the spray head includes a plurality of spray nozzles, and the plurality of spray nozzles are evenly spaced and distributed along the flow cross section of the flue gas in the removal tower body 1.

[0032] It can be understood that the multiple spray nozzles are evenly spaced and distributed along the flow cross section of the flue gas in the removal tower body 1, so that the flue gas can be evenly sprayed, which is beneficial to improving the spraying effect of the flue gas.

[0033] In this embodiment, the temperature of the spray liquid sprayed by the spray component 3 is 0°C to 20°C.

[0034] For example, the temperature of the spray liquid can be set to 0°C, 3°C, 5°C, 8°C, 10°C, 13°C, 15°C, 18°C ​​or 20°C, etc. If the temperature of the spray liquid is too low, the water in the spray liquid may freeze and cannot be sprayed. If the temperature of the spray liquid is too high, it will be difficult for the water vapor and other volatile substances in the airflow to be effectively condensed, so that the demister cannot fully function, thereby reducing the overall demisting efficiency. In this embodiment, the temperature of the spray liquid is preferably set to 0°C, which is conducive to maximizing the removal efficiency of particulate matter and SO3.

[0035] It is understandable that the temperature of the spray liquid is set to 0℃~20℃. The low-temperature spray liquid rapidly reduces the flue gas temperature and condenses the water vapor into fine water droplets. These water droplets collide with the particles in the flue gas and condense to form larger particle agglomerates, which are more easily captured by subsequent treatment equipment, thereby improving the removal efficiency of particles. The spray liquid directly contacts the particles, dissolves or fixes them in the droplets through physical adsorption and chemical reaction, and is discharged from the removal device with the liquid. In addition, the low temperature will cause SO3 to combine with water vapor, reducing the SO3 concentration in the flue gas.

[0036] In this embodiment, if Figure 1 As shown, the device for removing particulate matter and SO3 in flue gas also includes a packing layer 4, which is arranged in the removal tower body 1 and is located below the spray head.

[0037] In detail, the filler of the packing layer 4 can be a regular packing or a random packing, which can be selected according to actual conditions and is not limited here. For example, the packing layer 4 can be a spherical bulk packing.

[0038] It can be understood that by providing the packing layer 4, the contact area between the gas and liquid phases can be increased, thereby improving the mass transfer efficiency and prolonging the contact time between the gas and liquid, which is beneficial to improving the removal efficiency of SO3 and particulate matter.

[0039] In this embodiment, if Figure 1 As shown, the spray heads are arranged in multiple groups, the filler layer 4 is arranged in multiple layers, and the multiple groups of spray heads and the multiple layers of filler layers 4 are alternately arranged from bottom to top.

[0040] For example, there are four groups of spray heads and four layers of packing layer 4, then in the removal tower body 1, from bottom to top, there are first packing layer 4, first spray head, second packing layer 4, second spray head, third packing layer 4, third spray head, fourth packing layer 4, and fourth spray head. Of course, the number of spray heads and packing layers 4 can be selected as needed and is not limited here.

[0041] It can be understood that by setting up multiple groups of spray heads and multiple layers of packing layers 4, and arranging the multiple groups of spray heads and multiple layers of packing layers 4 alternately from bottom to top, the flue gas can pass through the multiple layers of packing layers 4 and multiple layers of spraying, which is beneficial to improving the removal efficiency of the flue gas.

[0042] In this embodiment, the flow rate of the flue gas entering the removal tower body 1 is 2.5 m / s to 3.8 m / s.

[0043] For example, the flow rate of the flue gas can be set to 2.5m / s, 2.7m / s, 3m / s, 3.2m / s, 3.5m / s or 3.8m / s, etc. If the flow rate of the flue gas is too low, the treatment efficiency of the flue gas will be reduced. If the flow rate of the flue gas is too high, the residence time of the flue gas in the removal tower body 1 will be reduced, and the mass transfer and heat transfer process between the gas-liquid two phases will be insufficient, which will affect the removal efficiency of the pollutants.

[0044] It can be understood that by setting the flow rate of the flue gas entering the removal tower body 1 to 2.5m / s to 3.8m / s, the flue gas can stay in the removal tower body 1 for an appropriate length of time, so that the gas-liquid two-phase has sufficient time for mass transfer and heat transfer, thereby improving the absorption and cooling effect of pollutants. In addition, the demister can more effectively capture droplets, reduce liquid foam entrainment, ensure that the discharged gas meets the emission standards, and avoid liquid waste.

[0045] In this embodiment, if Figure 1 and Figure 2 As shown, the device for removing particulate matter and SO3 in flue gas also includes an airflow homogenizer 5, which is arranged at the bottom of the removal tower body 1 to evenly distribute the flue gas entering the removal tower body 1.

[0046] It can be understood that by setting up an airflow homogenization component, the flue gas entering the removal tower body 1 is evenly distributed, the situation where the local airflow is too strong or too weak is reduced, and the gas-liquid contact conditions on the cross section of the removal tower body 1 are consistent, which is conducive to effective mass and heat transfer in each area, thereby improving the removal rate and treatment efficiency of pollutants.

[0047] In this embodiment, if Figure 2 As shown, the airflow homogenizer 5 is annular and encloses an annular cavity 51 with the inner circumferential wall of the removal tower body 1. The airflow homogenizer 5 is provided with an inlet connected to the smoke inlet 11, and the inner side wall of the annular cavity 51 is provided with a plurality of outlets 52 evenly distributed along the circumference of the annular cavity 51, and the outlets 52 are arranged to be inclined downward.

[0048] Specifically, the smoke inlet 11 extends along the tangent direction of the annular cavity 51, so that smoke can enter the annular cavity 51 from the tangent direction of the annular cavity 51, naturally forming a rotational motion, which is conducive to the smoke entering the annular cavity 51 smoothly, thereby reducing resistance.

[0049] The upper part of the inner ring of the air flow homogenizing member 5 forms an annular cone surface inclined downward, so that the liquid falling from above can fall smoothly along the cone surface.

[0050] It is understandable that after the smoke enters the annular cavity 51 from the smoke inlet 11 and the inlet of the annular cavity 51, it is discharged from the outlet 52 of the annular cavity 51. The smoke is distributed along the circumference of the degassing tower body 1 through the guidance of the annular cavity 51, so that the smoke can be evenly discharged from the outlet 52 of the annular cavity 51. In addition, the outlet 52 is arranged to be tilted downward, which can make the smoke more fully mixed, and help to make the smoke more evenly distributed on the cross section of the entire degassing tower body 1.

[0051] In this embodiment, the angle between the extension direction of the outlet 52 and the side wall of the removal tower body 1 is 20° to 45°.

[0052] For example, the angle between the extension direction of the outlet 52 and the side wall of the removal tower body 1 can be 20°, 25°, 30°, 35°, 40° or 45°, etc. If the angle is too small, the impact force of the flue gas will be too large, and the fixture will wear the removal tower body 1. If the angle is too small, the mass transfer and heat transfer effects will be affected.

[0053] In this embodiment, by setting the angle between the extension direction of the outlet 52 and the side wall of the removal tower body 1 to 20° to 45°, it is beneficial to balance the air flow velocity, mass transfer and heat transfer effects, and reduce the wear on the removal tower body 1.

[0054] In this embodiment, the device for removing particulate matter and SO3 from flue gas is equipped with multiple packing layers 4, multiple groups of spray heads, and a two-stage demister, and the particle removal efficiency is increased to 92.18%, and the SO3 removal efficiency is increased to 93.86% under the condition that the spray liquid temperature is 0°C.

[0055] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0056] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0057] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0058] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0059] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean 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 representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0060] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A device for removing particulate matter and SO3 from flue gas, characterized in that: include: A removal tower body, wherein the bottom side wall of the removal tower body is provided with a smoke inlet, and the top of the removal tower body is provided with a smoke exhaust port connected to the smoke inlet; A demister assembly, the demister assembly is arranged above the removal tower body, the demister assembly includes a primary demister and a secondary demister which are arranged in sequence from bottom to top, the primary demister and the secondary demister are baffle demisters, the blade spacing of the primary demister is A, the blade spacing of the secondary demister is B, A is 20 mm to 95 mm, B is 20 mm to 95 mm, and B=60% to 70% of A; A spray assembly, wherein the spray head of the spray assembly is arranged in the removal tower body and is located between the smoke inlet and the demisting assembly.

2. The device for removing particulate matter and SO3 from flue gas according to claim 1, characterized in that: The height between the bottom of the primary demister and the top of the secondary demister is 3.5m to 4.5m.

3. The device for removing particulate matter and SO3 from flue gas according to claim 1, characterized in that: The spray head comprises a plurality of spray nozzles, and the plurality of spray nozzles are evenly spaced and distributed along a flow cross section of the flue gas in the removal tower body.

4. The device for removing particulate matter and SO3 from flue gas according to claim 3 is characterized in that: The temperature of the spray liquid sprayed from the spray nozzle is 0°C to 20°C.

5. The device for removing particulate matter and SO3 from flue gas according to claim 1, characterized in that: It also includes a packing layer, which is arranged in the removal tower body and is located below the spray head.

6. The device for removing particulate matter and SO3 from flue gas according to claim 5, characterized in that: The spray heads are arranged in multiple groups, the filler layers are arranged in multiple layers, and the multiple groups of spray heads and the multiple layers of filler layers are alternately arranged from bottom to top.

7. The device for removing particulate matter and SO3 from flue gas according to claim 1, characterized in that: The flow rate of flue gas entering the removal tower body is 2.5m / s to 3.8m / s.

8. The device for removing particulate matter and SO3 from flue gas according to any one of claims 1 to 7, characterized in that: It also includes an airflow homogenizing member, which is arranged at the bottom of the removal tower body and is used to evenly distribute the flue gas entering the removal tower body.

9. The device for removing particulate matter and SO3 from flue gas according to claim 8, characterized in that: The airflow homogenizing member is annular and encloses an annular cavity with the inner circumferential wall of the removal tower body. The airflow homogenizing member is provided with an inlet connected to the smoke inlet, and the inner side wall of the annular cavity is provided with a plurality of outlets evenly distributed along the circumference of the annular cavity, and the outlets are arranged to be inclined downward.

10. The device for removing particulate matter and SO3 from flue gas according to claim 9, characterized in that: The angle between the extension direction of the outlet and the side wall of the removal tower body is 20° to 45°.

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