Exhaust gas treatment device and method for a boiler

Abstract

The application provides a boiler waste gas treatment device and method, and belongs to the technical field of boiler waste gas treatment. The boiler waste gas treatment device comprises a waste gas treatment tower, a first spraying assembly, a filler bed and a second spraying assembly which are arranged in the waste gas treatment tower. The filler bed is located between the first spraying assembly and the second spraying assembly. The bottom of the waste gas treatment tower is connected with an air inlet pipe and a liquid outlet pipe. The top of the waste gas treatment tower is connected with an exhaust pipe. An annular partition is arranged at the bottom of the inner cavity of the waste gas treatment tower. A vertical pipe is arranged in the middle of the annular partition. A spiral blade is arranged at the bottom end of the inner arc wall of the waste gas treatment tower and is located below the annular partition. The air outlet of the air inlet pipe is located below the annular partition and is higher than the bottom opening of the vertical pipe and faces the tangential direction of the inner arc wall of the waste gas treatment tower. The application can reduce the possibility of the filler bed being blocked by dust particles and precipitates, thereby improving the treatment effect of the boiler waste gas.

Description

Technical Field

[0001] This application relates to the field of boiler exhaust gas treatment technology, specifically to a boiler exhaust gas treatment device and method. Background Technology

[0002] Boiler exhaust gas refers to the waste gas emitted during boiler combustion, mainly including carbon dioxide, water vapor, unburned fuel components (such as hydrocarbons and carbon monoxide), nitrogen oxides, sulfur oxides, particulate matter, and various other impurities. When these gases are released into the atmosphere, they can cause environmental pollution, including decreased air quality, acid rain formation, and the greenhouse effect. Therefore, to protect the environment and public health, boiler exhaust gas must be effectively treated, typically employing various technologies such as desulfurization, dust removal, and denitrification to ensure emissions comply with national and local environmental regulations.

[0003] The specific composition and properties of boiler exhaust gas are influenced by a variety of factors, including the type of fuel used (coal, oil, natural gas, or other alternative energy sources), combustion temperature and efficiency, fuel quality, and the boiler's design, regulation, and operating conditions. Different conditions lead to variations in the emission proportions and concentrations of different pollutants. For example, coal combustion produces exhaust gas containing more sulfides and dust, while natural gas combustion emits less sulfur oxides and particulate matter. To reduce the emission of harmful pollutants, appropriate exhaust gas treatment devices are often installed in boiler systems to treat the boiler exhaust gas.

[0004] Referring to Chinese patent document CN215585788U, published on January 21, 2022, entitled "A Waste Gas Treatment Device for a Boiler," the device includes a waste gas treatment chamber in the shape of a cuboid. An outlet pipe is connected to the upper surface of the top plate of the waste gas treatment chamber. A filter chamber is installed in the upper part of the inner cavity of the waste gas treatment chamber. An activated carbon adsorption layer is horizontally inserted in the upper part of the inner cavity of the filter chamber. Dust filter cotton is horizontally inserted in the middle part of the inner cavity of the filter chamber. A dust filter screen is horizontally inserted in the lower part of the inner cavity of the filter chamber. The activated carbon adsorption layer, dust filter cotton, and dust filter cotton are... Each dust filter screen has a pull handle fixed to its front side. Pull rods are longitudinally inserted through the four corners of the bottom plate of the exhaust gas treatment chamber, and a connecting rod is fixed to the bottom end of every two adjacent pull rods. A cleaning plate is fixed to the top of each pull rod, and cleaning brushes are installed on the outer periphery of the cleaning plate. An air inlet pipe is connected to the center of the lower surface of the bottom plate of the exhaust gas treatment chamber. Support legs are fixed to the four corners of the bottom of the exhaust gas treatment chamber. A return pipe is located on the right side of the exhaust gas treatment chamber. The air inlet of the return pipe is connected to the upper right side of the exhaust gas treatment chamber, and the air outlet is connected to the lower right side of the exhaust gas treatment chamber. This device allows the cleaning plate and cleaning brushes to move up and down by pulling the connecting rods, thus scraping off the coal ash adsorbed on the inner wall of the device. This prevents the coal ash from re-entering the exhaust gas and increasing the purification burden on the device, thereby improving the purification efficiency.

[0005] Referring to the above technical solution, when using a packed bed and sprayed calcium hydroxide solution for desulfurization of boiler exhaust gas, the sulfides in the exhaust gas react with the calcium hydroxide solution to form calcium sulfite precipitate, and this reaction mainly occurs on the packed bed, easily leading to the gradual accumulation of precipitate on the packed bed. Furthermore, dust particles in the exhaust gas also tend to accumulate on the packed bed, causing blockage and covering, thereby reducing the mass transfer efficiency and reaction effect of the packed bed. The accumulation of these precipitates and dust not only affects desulfurization efficiency but may also damage the treatment equipment, increase maintenance costs, and affect the stable operation of the entire desulfurization system. Summary of the Invention

[0006] In view of this, this application provides a boiler exhaust gas treatment device and method, mainly used to solve the problem that the packing bed is easily blocked by dust particles and sediments, which affects the boiler exhaust gas treatment effect.

[0007] To solve the above-mentioned technical problems, this application provides a boiler exhaust gas treatment device and method.

[0008] In a first aspect, this application provides a boiler exhaust gas treatment device, including an exhaust gas treatment tower and a first spray assembly, a packing bed, and a second spray assembly disposed inside it. The packing bed is located between the first spray assembly and the second spray assembly. An air inlet pipe and a liquid outlet pipe are connected to the bottom of the exhaust gas treatment tower, and an exhaust pipe is connected to the top of the exhaust gas treatment tower. An annular baffle is disposed at the bottom of the inner cavity of the exhaust gas treatment tower, and a vertical pipe is disposed through the middle of the annular baffle. A spiral blade is disposed at the bottom end of the inner arc wall of the exhaust gas treatment tower, and the spiral blade is located below the annular baffle. The air inlet of the air inlet pipe is located below the annular baffle and higher than the bottom opening of the vertical pipe, and the air inlet of the air inlet pipe is aligned with the tangential direction of the inner arc wall of the exhaust gas treatment tower. The air inlet pipe can blow the supplied boiler exhaust gas toward the location of the spiral blade.

[0009] By adopting the above technical solution, during the boiler exhaust gas treatment process, the boiler exhaust gas is sent to the bottom of the exhaust gas treatment tower through the inlet pipe. Under the constraint of the nozzle orientation of the inlet pipe, the boiler exhaust gas moves tangentially along the inner arc wall of the exhaust gas treatment tower. Ultimately, the boiler exhaust gas contacts the inner wall of the tower and gains a certain centrifugal force. Because dust particles are relatively heavy, they gradually concentrate on the spiral blades as the boiler exhaust gas continuously flows in and moves downwards along the spiral blades. After moving downwards along the spiral for a certain distance, the exhaust gas can flow upwards through the vertical pipe, thereby achieving preliminary separation of dust. This effectively reduces the risk of dust particles clogging the packing bed during subsequent desulfurization processes and improves the overall desulfurization efficiency.

[0010] Optionally, the top opening of the vertical pipe is flared and inclined from bottom to top in a direction away from its own central axis, and the edge of the top opening of the vertical pipe is fixedly connected to the inner arc wall of the exhaust gas treatment tower.

[0011] By adopting the above technical solution, when the boiler exhaust gas moves upward along the vertical pipe to its top opening, the flow rate of the boiler exhaust gas will gradually slow down as the diameter of the top opening gradually increases. This provides more time for the boiler exhaust gas to fully mix with the calcium hydroxide solution, which helps to improve the desulfurization effect and the desulfurization quality.

[0012] Optionally, the first spray assembly includes an annular spray pipe installed in the middle of the inner cavity of the exhaust gas treatment tower via a truss, a liquid supply pipe communicating with the annular spray pipe is installed through the exhaust gas treatment tower, and a vertical pipe is located directly below the annular spray pipe.

[0013] By adopting the above technical solution, as the boiler exhaust gas flows upward along the vertical pipe, the liquid supply pipe can introduce calcium hydroxide solution into the annular spray pipe and spray it downward, so that the calcium hydroxide solution is initially mixed with the rising boiler exhaust gas, thereby performing preliminary desulfurization treatment on the sulfides in the exhaust gas, reducing the subsequent burden on the packing bed, and thus reducing the risk of calcium sulfite precipitation clogging the packing bed.

[0014] Optionally, the inner cavity of the exhaust gas treatment tower is equipped with a flushing assembly for flushing the spiral blades.

[0015] Optionally, the flushing assembly includes a solution storage cavity disposed between the vertical pipe, the exhaust gas treatment tower, and the annular baffle. Multiple filter holes communicating with the solution storage cavity are arrayed on the inclined pipe wall with an open top of the vertical pipe. Multiple leakage holes communicating with the solution storage cavity and the inner cavity of the exhaust gas treatment tower are arrayed at the edge of the annular baffle, and the leakage holes are located directly above the spiral blades.

[0016] By adopting the above technical solution, when the first spray assembly sprays the calcium hydroxide solution downwards, a portion of the solution falls onto the inclined wall of the vertical pipe and continues to slide down. This portion of the calcium hydroxide solution passes through the filter holes into the solution storage chamber and then onto the spiral blades through the leakage holes. Utilizing the liquid surface tension of the calcium hydroxide solution, the adsorption capacity of the spiral blades is enhanced, making them more effective at adsorbing dust particles in the exhaust gas. Simultaneously, as the calcium hydroxide solution continues to slide down the spiral blades, it also washes away the dust adhering to the spiral blades, ensuring the efficiency of subsequent exhaust gas treatment.

[0017] Optionally, the vertical tube has multiple overflow holes arranged in a circumferential array on its wall, which are connected to the solution storage chamber. The overflow holes are located between the annular partition and the filter holes.

[0018] By adopting the above technical solution, the overflow hole can maintain a stable water level of calcium hydroxide solution in the solution storage chamber, which can not only ensure that the spiral blades are fully flushed, but also use calcium hydroxide solution to seal the leakage hole, preventing boiler exhaust gas entering through the air inlet pipe from rising directly from the leakage hole.

[0019] Optionally, the annular spray pipe is provided with multiple fan-shaped diversion plates, and the fan-shaped diversion plates at different heights are staggered in the circumferential direction.

[0020] By adopting the above technical solution, multiple fan-shaped diversion plates work together to receive and guide the calcium hydroxide solution falling from above, causing it to flow along the inclined wall of the vertical pipe to the edge of the open top of the vertical pipe. This ensures that the calcium hydroxide solution enters the solution storage chamber through the filter holes, guaranteeing that the solution storage chamber continuously receives a sufficient supply of calcium hydroxide solution.

[0021] Secondly, this application provides a boiler exhaust gas treatment method, applied to the boiler exhaust gas treatment device described in the first aspect, comprising the following steps:

[0022] S1. First, the boiler exhaust gas is introduced into the exhaust gas treatment tower through the inlet pipe. Under the restriction of the jet nozzle direction of the inlet pipe, the boiler exhaust gas moves along the tangential direction of the inner arc wall of the exhaust gas treatment tower and obtains a certain centrifugal force, so that the dust particles in the boiler exhaust gas gradually concentrate on the spiral blades and move downward along the spiral blades. After moving downward through the spiral for a certain distance, the boiler exhaust gas can flow upward through the vertical pipe, thereby achieving the initial separation of dust particles.

[0023] S2, when the boiler exhaust gas moves upward along the vertical pipe, the first spray component sprays calcium hydroxide solution downward and mixes it with the rising boiler exhaust gas in the initial stage, thereby reducing the sulfide content in the exhaust gas, thus reducing the subsequent treatment burden on the packing bed and reducing the risk of calcium sulfite precipitate clogging the packing bed.

[0024] S3, the boiler exhaust gas, after preliminary spray desulfurization treatment, continues to rise to the packing bed. Then, the second spray component sprays calcium hydroxide solution downwards to mix with the boiler exhaust gas inside the packing bed, thereby completing the secondary spray desulfurization treatment of the boiler exhaust gas. Finally, the treated boiler exhaust gas will be discharged through the exhaust pipe connected to the top of the exhaust gas treatment tower.

[0025] By adopting the above technical solution and adding pretreatment measures to the existing spray packing desulfurization tower, it is possible to simultaneously achieve the pre-removal of particulate matter in the exhaust gas and the preliminary adsorption of sulfides, thereby reducing the burden on the packing bed and improving the overall desulfurization efficiency.

[0026] Optionally, in step S2, as the diameter of the top opening of the vertical pipe gradually increases, when the boiler exhaust gas moves upward along the vertical pipe to the top opening of the vertical pipe, the overall flow velocity of the boiler exhaust gas will gradually decrease, allowing the boiler exhaust gas to mix with the calcium hydroxide solution for a longer period of time.

[0027] By adopting the above technical solution, the boiler exhaust gas and calcium hydroxide solution are mixed more thoroughly by reducing the boiler exhaust gas flow rate, thereby improving the desulfurization effect.

[0028] Optionally, in steps S2 and S3, when the first spray assembly and the second spray assembly spray the calcium hydroxide solution downwards, some of the calcium hydroxide solution will fall onto the inclined pipe wall of the vertical pipe and enter the solution storage chamber through the filter holes. Subsequently, the calcium hydroxide solution inside the solution storage chamber can fall onto the spiral blades through the leakage holes. The liquid surface tension of the calcium hydroxide solution is used to enhance the adsorption capacity of the spiral blades, making them more effective in adsorbing dust in the flow of boiler exhaust gas. At the same time, the continuous falling of the calcium hydroxide solution along the spiral blades can wash down the dust particles attached to the spiral blades, preventing the dust particles from accumulating in large quantities on the spiral blades.

[0029] By adopting the above technical solution, the calcium hydroxide solution can be recycled. The liquid surface tension of the calcium hydroxide solution can be used to enhance the adsorption capacity of the spiral plate. At the same time, the dust particles attached to the spiral plate can be washed off to prevent the dust particles from accumulating on the spiral plate.

[0030] In summary, compared with the prior art, this application includes at least one of the following beneficial technical effects:

[0031] 1. When treating boiler exhaust gas, this device can pre-separate dust particles during the intake process, preventing them from clogging the packing bed during subsequent desulfurization. It can also pre-adsorb sulfides in the exhaust gas, reducing their concentration and thus lessening the processing burden on the packing bed. This improves the overall desulfurization efficiency of the boiler exhaust gas and extends the service life of the packing.

[0032] 2. During the spray desulfurization process of boiler exhaust gas, calcium hydroxide solution can be guided onto the spiral blades. The liquid surface tension of the calcium hydroxide solution enhances the adsorption capacity of the spiral blades, allowing them to more effectively adsorb dust particles from the boiler exhaust gas and improve dust removal efficiency. Simultaneously, the scouring effect of the calcium hydroxide solution washes away dust particles adhering to the spiral blades, preventing excessive accumulation and ensuring the spiral blades maintain high adsorption performance in subsequent treatment processes. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the structure of a boiler exhaust gas treatment device according to this application;

[0034] Figure 2 A cross-sectional view of the exhaust gas treatment tower of this application. Figure 1 ;

[0035] Figure 3 A cross-sectional view of the exhaust gas treatment tower of this application. Figure 2 ;

[0036] Figure 4 For this application Figure 3 A magnified view of a portion of region A in the middle;

[0037] Figure 5 For this application Figure 3 A magnified view of a portion of region B in the middle;

[0038] Figure 6 This is a schematic diagram of the fan-shaped drainage plate of this application.

[0039] Explanation of reference numerals in the attached drawings: 1. Waste gas treatment tower; 11. Inlet pipe; 12. Drain pipe; 13. Exhaust pipe; 2. First spray assembly; 21. Annular spray pipe; 22. Liquid supply pipe; 3. Packed bed; 4. Second spray assembly; 5. Annular baffle; 51. Vertical pipe; 52. Spiral blade; 6. Flushing assembly; 61. Solution storage chamber; 62. Filter hole; 63. Leakage hole; 64. Overflow hole; 7. Fan-shaped guide plate. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the following will be combined with the embodiments of this application. Figures 1-6 The technical solutions of the embodiments of this application are clearly and completely described herein. All other embodiments obtained by those skilled in the art based on the described embodiments are within the scope of protection of this application.

[0041] In a first aspect, this application provides a boiler exhaust gas treatment device, which adopts the following technical solution:

[0042] Reference Figure 1 and Figure 2 This embodiment provides a boiler exhaust gas treatment device, including an exhaust gas treatment tower 1 and a pretreatment component, a first spray component 2, a packing bed 3, and a second spray component 4 disposed therein. The first spray component 2 works in conjunction with the pretreatment component to perform preliminary desulfurization treatment on the boiler exhaust gas. The packing bed 3 is located between the first spray component 2 and the second spray component 4. The second spray component 4 works in conjunction with the packing bed 3 to perform secondary desulfurization treatment on the boiler exhaust gas. The bottom of the exhaust gas treatment tower 1 is connected to an inlet pipe 11 and a drain pipe 12, and the top of the exhaust gas treatment tower 1 is connected to an exhaust pipe 13.

[0043] Among them, reference Figure 2 , Figure 3 and Figure 4 The pretreatment assembly includes an annular baffle 5, a vertical pipe 51, and a spiral blade 52. The annular baffle 5 is located at the bottom of the inner cavity of the exhaust gas treatment tower 1, the vertical pipe 51 is installed through the middle of the annular baffle 5, the spiral blade 52 is located at the bottom end of the inner arc wall of the exhaust gas treatment tower 1, and the spiral blade 52 is located below the annular baffle 5. The nozzle of the air inlet pipe 11 is located below the annular baffle 5 and higher than the bottom opening of the vertical pipe 51. The nozzle of the air inlet pipe 11 is aligned with the tangential direction of the inner arc wall of the exhaust gas treatment tower 1. The air inlet pipe 11 can blow the supplied boiler exhaust gas toward the location of the spiral blade 52.

[0044] When carrying out boiler exhaust gas treatment, the boiler exhaust gas is first sent into the bottom of the inner cavity of the exhaust gas treatment tower 1 through the inlet pipe 11. Due to the orientation of the jet nozzle of the inlet pipe 11, the boiler exhaust gas will move along the tangential direction of the inner arc wall of the exhaust gas treatment tower 1 and come into contact with the inner arc wall of the exhaust gas treatment tower 1. At the same time, the boiler exhaust gas can have a certain centrifugal force. Since the dust particles are relatively heavy, as the boiler exhaust gas continues to flow in, the dust particles inside the boiler exhaust gas will gradually concentrate on the spiral blade 52 and move downward along the spiral blade 52. After moving downward through the spiral for a certain distance, the boiler exhaust gas moves upward through the vertical pipe 51. This achieves the initial dust separation work and reduces the possibility of dust particles clogging the packing bed 3 in the subsequent desulfurization process.

[0045] Additionally, refer to Figure 2 and Figure 3 The top opening of the vertical pipe 51 is flared and inclined from bottom to top in a direction away from its own central axis, and the edge of the top opening of the vertical pipe 51 is fixedly connected to the inner arc wall of the exhaust gas treatment tower 1.

[0046] As the boiler exhaust gas moves upward along the vertical pipe 51 to the top opening of the vertical pipe 51, the overall flow velocity of the boiler exhaust gas will decrease as the diameter of the top opening of the vertical pipe 51 gradually increases. This allows the boiler exhaust gas to have more time to mix with the calcium hydroxide solution sprayed from the first spray assembly 2, which is beneficial to improving the desulfurization quality.

[0047] Reference Figure 2 and Figure 3 The first spray assembly 2 includes an annular spray pipe 21 and a liquid supply pipe 22. The annular spray pipe 21 is installed in the middle of the inner cavity of the waste gas treatment tower 1 through a truss, and the liquid supply pipe 22 is installed through the waste gas treatment tower 1 and communicates with the annular spray pipe 21. The vertical pipe 51 is located directly below the annular spray pipe 21.

[0048] As the boiler exhaust gas moves upward along the vertical pipe 51, the liquid supply pipe 22 can send calcium hydroxide solution into the annular spray pipe 21. Then, the calcium hydroxide solution can be sprayed downward through the spray holes on the annular spray pipe 21 and initially mixed with the rising boiler exhaust gas. This is to preliminarily treat the sulfides in the boiler exhaust gas, reduce the subsequent treatment burden on the packing bed 3, and thus reduce the possibility of the packing bed 3 being blocked by calcium sulfite precipitate (the product of the reaction between sulfides in the boiler exhaust gas and calcium hydroxide solution).

[0049] Reference Figure 2 , Figure 3 , Figure 4 and Figure 5The exhaust gas treatment tower 1 is equipped with a flushing assembly 6 for flushing the spiral blades 52. The flushing assembly 6 includes a solution storage chamber 61, filter holes 62, and leakage holes 63. The solution storage chamber 61 is located between the vertical pipe 51, the exhaust gas treatment tower 1, and the annular baffle 5. The filter holes 62 are arrayed on the inclined pipe wall of the top opening of the vertical pipe 51 and communicate with the solution storage chamber 61. The leakage holes 63 are arrayed at the edge of the annular baffle 5, and the solution storage chamber 61 and the inner cavity of the exhaust gas treatment tower 1 are connected through the leakage holes 63. The leakage holes 63 are located directly above the spiral blades 52.

[0050] When the first spray assembly 2 sprays the calcium hydroxide solution downwards, some of the solution falls onto the inclined wall of the vertical pipe 51 and continues to fall along it. During this process, some of the solution enters the solution storage chamber 61 through the filter holes 62. Then, this portion of the solution enters the inner cavity of the exhaust gas treatment tower 1 through the leakage holes 63 and falls onto the spiral blades 52. The liquid surface tension of the calcium hydroxide solution enhances the adsorption performance of the spiral blades 52, allowing them to better adsorb dust particles during the intake of boiler exhaust gas. Furthermore, as the solution continues to fall along the spiral blades 52, it effectively washes away dust particles, preventing them from accumulating excessively and affecting the subsequent treatment of the boiler exhaust gas.

[0051] Reference Figure 2 , Figure 3 and Figure 4 The vertical tube 51 has multiple overflow holes 64 arranged in a circumferential array on its tube wall, which are connected to the solution storage chamber 61. The overflow holes 64 are located between the annular partition 5 and the filter holes 62.

[0052] Due to the presence of the overflow hole 64, the calcium hydroxide solution will maintain a sufficient water level inside the solution storage chamber 61. This not only allows the spiral blade 52 to be properly flushed by the calcium hydroxide solution, but also allows the calcium hydroxide solution to seal the leakage hole 63, preventing the boiler exhaust gas introduced through the air inlet pipe 11 from rising directly through the leakage hole 63 and affecting the treatment effect of the boiler exhaust gas.

[0053] Reference Figure 2 , Figure 3 and Figure 6 The annular spray pipe 21 is provided with multiple fan-shaped diversion plates 7, and the fan-shaped diversion plates 7 at different heights are staggered in the circumferential direction.

[0054] When the first spray assembly 2 and the second spray assembly 4 spray the calcium hydroxide solution downwards, multiple fan-shaped guide plates 7 cooperate to cover an entire circumferential surface. Then, the fan-shaped guide plates 7 can receive the calcium hydroxide solution falling from above and guide it towards the edge of the top opening of the vertical pipe 51, so that the calcium hydroxide solution can fall along the inclined pipe wall of the vertical pipe 51 and enter the solution storage chamber 61 through the filter hole 62, so that the solution storage chamber 61 can receive sufficient calcium hydroxide solution replenishment.

[0055] The implementation principle of a boiler exhaust gas treatment device according to an embodiment of this application is as follows:

[0056] When carrying out boiler exhaust gas treatment, the boiler exhaust gas is first sent into the bottom of the inner cavity of the exhaust gas treatment tower 1 through the inlet pipe 11. Due to the orientation of the jet nozzle of the inlet pipe 11, the boiler exhaust gas will move along the tangential direction of the inner arc wall of the exhaust gas treatment tower 1 and come into contact with the inner arc wall of the exhaust gas treatment tower 1. At the same time, the boiler exhaust gas can have a certain centrifugal force. Since the dust particles are relatively heavy, as the boiler exhaust gas continues to flow in, the dust particles inside the boiler exhaust gas will gradually concentrate on the spiral blade 52 and move downward along the spiral blade 52. After moving downward through the spiral for a certain distance, the boiler exhaust gas moves upward through the vertical pipe 51. This achieves the initial dust separation work and reduces the possibility of dust particles clogging the packing bed 3 in the subsequent desulfurization process.

[0057] As the boiler exhaust gas moves upward along the vertical pipe 51, the liquid supply pipe 22 can send calcium hydroxide solution into the annular spray pipe 21. Then, the calcium hydroxide solution can be sprayed downward through the spray holes opened on the annular spray pipe 21 and preliminarily mixed with the rising boiler exhaust gas. This is to preliminarily treat the sulfides in the boiler exhaust gas, reduce the subsequent treatment burden of the packing bed 3, and thus reduce the possibility of the packing bed 3 being blocked by calcium sulfite precipitate.

[0058] In addition, as the boiler exhaust gas moves upward along the vertical pipe 51 to the top opening of the vertical pipe 51, the overall flow velocity of the boiler exhaust gas will decrease as the diameter of the top opening of the vertical pipe 51 gradually increases. This allows the boiler exhaust gas to have more time to mix with the calcium hydroxide solution sprayed by the first spray assembly 2, which is beneficial to improving the desulfurization quality.

[0059] Then the boiler exhaust gas continues to rise to the packing bed 3, and the second spray component 4 sprays calcium hydroxide solution downwards to mix with the boiler exhaust gas inside the packing bed 3, thereby completing the final desulfurization treatment of the boiler exhaust gas. The treated boiler exhaust gas will be discharged through the exhaust pipe 13 connected to the top of the exhaust gas treatment tower 1.

[0060] In addition, when the first spray assembly 2 and the second spray assembly 4 spray the calcium hydroxide solution downwards, some of the calcium hydroxide solution will fall onto the inclined wall of the vertical pipe 51 and continue to fall along the inclined wall of the vertical pipe 51. During this process, some of the calcium hydroxide solution can enter the solution storage chamber 61 through the filter hole 62. Then, this part of the calcium hydroxide solution can enter the inner cavity of the exhaust gas treatment tower 1 through the leakage hole 63 and fall onto the spiral blade 52. With the help of the liquid surface tension of the calcium hydroxide solution, the adsorption performance of the spiral blade 52 is improved, so that the spiral blade 52 can better adsorb dust particles during the intake of boiler exhaust gas. Moreover, as the calcium hydroxide solution continues to fall along the spiral blade 52, it can better wash the dust particles on the spiral blade 52 downwards, so as to prevent the dust particles from accumulating in large quantities on the spiral blade 52 and affecting the treatment effect of the subsequently introduced boiler exhaust gas.

[0061] Secondly, this application provides a boiler exhaust gas treatment method, applied to the boiler exhaust gas treatment apparatus of the first aspect, comprising the following steps:

[0062] S1. First, the boiler exhaust gas is introduced into the exhaust gas treatment tower 1 through the air inlet pipe 11. Under the restriction of the jet nozzle direction of the air inlet pipe 11, the boiler exhaust gas moves along the tangential direction of the inner arc wall of the exhaust gas treatment tower 1 and obtains a certain centrifugal force, so that the dust particles in the boiler exhaust gas gradually concentrate on the spiral blade 52 and move downward along the spiral blade 52. After moving downward through the spiral for a certain distance, the boiler exhaust gas can flow upward through the vertical pipe 51, thereby achieving the initial separation of dust particles.

[0063] S2, when the boiler exhaust gas moves upward along the vertical pipe 51, the liquid supply pipe 22 delivers calcium hydroxide solution to the annular spray pipe 21. The calcium hydroxide solution is sprayed downward through the spray holes on the annular spray pipe 21 and is initially mixed with the rising boiler exhaust gas, thereby reducing the sulfide content in the exhaust gas, thus reducing the subsequent treatment burden of the packing bed 3 and reducing the risk of calcium sulfite precipitate clogging the packing bed 3.

[0064] S3, the boiler exhaust gas, after preliminary spray desulfurization treatment, continues to rise to the packing bed 3. Then, the second spray component 4 sprays calcium hydroxide solution downwards and mixes it with the boiler exhaust gas inside the packing bed 3 to complete the secondary spray desulfurization treatment of the boiler exhaust gas. Finally, the treated boiler exhaust gas will be discharged through the exhaust pipe 13 connected to the top of the exhaust gas treatment tower 1.

[0065] In step S2, as the diameter of the top opening of the vertical pipe 51 gradually increases, when the boiler exhaust gas moves upward along the vertical pipe 51 to the top opening of the vertical pipe 51, the overall flow velocity of the boiler exhaust gas will gradually decrease, allowing the boiler exhaust gas to mix with the calcium hydroxide solution for a longer period of time.

[0066] In steps S2 and S3, when the first spray assembly 2 and the second spray assembly 4 spray the calcium hydroxide solution downwards, some of the calcium hydroxide solution will fall onto the inclined wall of the vertical pipe 51 and enter the solution storage chamber 61 through the filter hole 62. Subsequently, the calcium hydroxide solution inside the solution storage chamber 61 can fall onto the spiral blade 52 through the leakage hole 63. The liquid surface tension of the calcium hydroxide solution is used to enhance the adsorption capacity of the spiral blade 52, making it more effective in adsorbing dust in the flow of boiler exhaust gas. At the same time, the continuous falling of the calcium hydroxide solution along the spiral blade 52 can wash off the dust particles attached to the spiral blade 52, preventing the dust particles from accumulating in large quantities on the spiral blade 52.

[0067] The above description is the preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principles described in this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A boiler exhaust gas treatment device, comprising an exhaust gas treatment tower and a first spray assembly, a packing bed, and a second spray assembly disposed therein, the packing bed being located between the first spray assembly and the second spray assembly, an inlet pipe and a drain pipe connected to the bottom of the exhaust gas treatment tower, and an exhaust pipe connected to the top of the exhaust gas treatment tower, characterized in that: The bottom of the inner cavity of the exhaust gas treatment tower is provided with an annular baffle, and a vertical pipe is installed through the middle of the annular baffle. A spiral blade is provided at the bottom of the inner arc wall of the exhaust gas treatment tower, and the spiral blade is located below the annular baffle. The air inlet of the air inlet pipe is located below the annular baffle and higher than the bottom opening of the vertical pipe. The air inlet of the air inlet pipe is aligned with the tangent direction of the inner arc wall of the exhaust gas treatment tower. The air inlet pipe can blow the supplied boiler exhaust gas toward the location of the spiral blade. The top opening of the vertical pipe is flared and inclined from bottom to top in a direction away from its own central axis, and the edge of the top opening of the vertical pipe is fixedly connected to the inner arc wall of the exhaust gas treatment tower. The exhaust gas treatment tower is equipped with a flushing assembly for flushing the spiral blades. The flushing assembly includes a solution storage chamber disposed between the vertical pipe, the exhaust gas treatment tower, and the annular baffle. Multiple filter holes communicating with the solution storage chamber are arrayed on the inclined pipe wall with an open top of the vertical pipe. Multiple leakage holes communicating with the solution storage chamber and the inner cavity of the exhaust gas treatment tower are arrayed at the edge of the annular baffle, and the leakage holes are located directly above the spiral blades.

2. The boiler exhaust gas treatment device according to claim 1, characterized in that: The first spray assembly includes an annular spray pipe installed in the middle of the inner cavity of the exhaust gas treatment tower via a truss. A liquid supply pipe communicating with the annular spray pipe is installed through the exhaust gas treatment tower, and a vertical pipe is located directly below the annular spray pipe.

3. The boiler exhaust gas treatment device according to claim 1, characterized in that: The vertical tube has multiple overflow holes arranged in a circumferential array on its wall, which are connected to the solution storage chamber. The overflow holes are located between the annular partition and the filter holes.

4. The boiler exhaust gas treatment device according to claim 2, characterized in that: The annular spray pipe is equipped with multiple fan-shaped diversion plates, and the fan-shaped diversion plates at different heights are staggered in the circumferential direction.

5. A method for treating boiler exhaust gas, applied to the boiler exhaust gas treatment device according to claim 1, characterized in that, Includes the following steps: S1. First, the boiler exhaust gas is introduced into the exhaust gas treatment tower through the inlet pipe. Under the restriction of the jet nozzle direction of the inlet pipe, the boiler exhaust gas moves along the tangential direction of the inner arc wall of the exhaust gas treatment tower and obtains a certain centrifugal force, so that the dust particles in the boiler exhaust gas gradually concentrate on the spiral blades and move downward along the spiral blades. After moving downward through the spiral for a certain distance, the boiler exhaust gas can flow upward through the vertical pipe, thereby achieving the initial separation of dust particles. S2, when the boiler exhaust gas moves upward along the vertical pipe, the first spray component sprays calcium hydroxide solution downward and mixes it with the rising boiler exhaust gas in the initial stage, thereby reducing the sulfide content in the exhaust gas, thus reducing the subsequent treatment burden on the packing bed and reducing the risk of calcium sulfite precipitate clogging the packing bed. S3, the boiler exhaust gas, after preliminary spray desulfurization treatment, continues to rise to the packing bed. Then, the second spray component sprays calcium hydroxide solution downwards to mix with the boiler exhaust gas inside the packing bed, thereby completing the secondary spray desulfurization treatment of the boiler exhaust gas. Finally, the treated boiler exhaust gas will be discharged through the exhaust pipe connected to the top of the exhaust gas treatment tower.

6. The boiler exhaust gas treatment method according to claim 5, characterized in that: In step S2, as the diameter of the top opening of the vertical pipe gradually increases, the overall flow velocity of the boiler exhaust gas gradually decreases when it moves upward along the vertical pipe to the top opening, allowing the boiler exhaust gas to mix with the calcium hydroxide solution for a longer period of time.

7. A method for treating boiler exhaust gas according to claim 5, characterized in that: In steps S2 and S3, when the first spray assembly and the second spray assembly spray the calcium hydroxide solution downwards, some of the calcium hydroxide solution will fall onto the inclined pipe wall of the vertical pipe and enter the solution storage chamber through the filter holes. Subsequently, the calcium hydroxide solution inside the solution storage chamber can fall onto the spiral blades through the leakage holes. The liquid surface tension of the calcium hydroxide solution is used to enhance the adsorption capacity of the spiral blades, making them more effective in adsorbing dust in the flow of boiler exhaust gas. At the same time, the continuous falling of the calcium hydroxide solution along the spiral blades can wash down the dust particles attached to the spiral blades, preventing the dust particles from accumulating in large quantities on the spiral blades.

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