Flue gas treatment dry deacidification tower for tail gas ammonia escape

Abstract

The invention belongs to the technical field of deacidification towers, and discloses a flue gas treatment dry-process deacidification tower for tail gas ammonia escape, which comprises a tower body, the tower body comprises a top cylinder, a gas inlet pipe orifice positioned at the lower part of the tower body, and a diffusion section connected with the gas inlet pipe orifice and the top cylinder; a plurality of spiral rib plates which are distributed in the circumferential direction and spirally ascend in the axial direction are fixedly arranged on the inner wall of the diffusion section. Through coupling matching of the central spindle-shaped adjusting cone and the multistage spiral rib plates on the inner wall of the diffusion section, a spiral flow channel with a continuously variable flow section is constructed, the flow channel section shrinks along with axial descending of the spindle-shaped adjusting cone, air flow is forced to be converted into wall-attached strong rotational flow from axial flow, and the flow efficiency is improved. The problem of powder collapse caused by insufficient turbulence intensity of a diffusion section under a low-load working condition is solved, the retention time of the deacidification powder in the tower is prolonged by utilizing enhanced centrifugal force, and gas-solid contact and mixing are enhanced, so that the deacidification efficiency is stably guaranteed and the ammonia escape risk is reduced under variable working conditions.

Description

Dry desulfurization tower for flue gas treatment to prevent ammonia escape in tail gas Technical Field

[0001] This invention belongs to the field of deacidification tower technology, specifically a dry deacidification tower for flue gas treatment to prevent ammonia escape in tail gas. Background Technology

[0002] In flue gas treatment processes involving ammonia escape, deacidification powder is typically added to the flue gas. This allows the powder to contact the flue gas within the tower and undergo a neutralization reaction, thereby reducing the acid gas content in the flue gas. In some flue gas treatment scenarios where ammonia escape occurs, the deacidification tower needs to complete powder dispersion and gas-solid contact within a relatively short residence time.

[0003] Existing dry desulfurization towers mostly use a cylindrical body with a lower diffuser structure to introduce flue gas, and incorporate flow guiding components within the tower to alter the flow path. However, in actual operation, flue gas flow rate and dust load fluctuate: when the flow rate is low or the disturbance is insufficient, powder is prone to localized deposition and wall adhesion near the diffuser section and flow guiding components. The deposited layer may collapse in blocks under airflow pulsation or ash discharge disturbance, causing sudden changes in local powder concentration, secondary dust generation, and pressure drop fluctuations. When it is necessary to clean the wall adhesion or suppress deposition, external purging pipelines or shutdown maintenance are often required. The tower's internal disturbance or purging methods lack a switchable linkage structure with the main flow field, making it difficult to quickly switch between "enhanced mixing" and "purging cleaning" according to operating conditions.

[0004] Therefore, a dry deacidification tower structure is needed that can form an adjustable spiral flow field inside the tower and switch the pressurized gas to an internal jet flow when needed to disturb and purge key areas inside the tower, so as to adapt to load fluctuations and reduce deposition and wall adhesion problems. Summary of the Invention

[0005] The purpose of this invention is to provide a dry desulfurization tower for flue gas treatment to prevent ammonia escape in the tail gas, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a dry desulfurization tower for flue gas treatment to prevent ammonia escape in tail gas, comprising a tower body, wherein the tower body includes a top cylinder, an air inlet located at the lower part of the tower body, and a diffuser section connecting the air inlet and the top cylinder;

[0007] The inner wall of the diffuser section is fixedly provided with multiple spiral ribs that are distributed circumferentially and spirally rise axially.

[0008] The diffuser section is provided with a central support shaft that can be raised and lowered axially, and the central support shaft is provided with a through air passage.

[0009] A spindle-shaped adjusting cone is sleeved on the outside of the central support shaft. The spindle-shaped adjusting cone and the spiral rib define the spiral flow channel and move axially with the central support shaft to adjust the equivalent flow cross-sectional area of ​​the spiral flow channel.

[0010] The top of the top cylinder is equipped with a control component for driving the central support shaft to rise and fall and supplying pressurized gas to the air passage;

[0011] The spindle-shaped adjusting cone has an assembly chamber and a connecting chamber inside, which are connected by a central hole, and the outer wall of the spindle-shaped adjusting cone has a spray hole that communicates with the connecting chamber.

[0012] It also includes a pneumatic flow channel switching mechanism. A bypass port communicating with the air channel is opened on the outside of the central support shaft. The pneumatic flow channel switching mechanism is set in the assembly chamber and is used to control the opening and closing of the bypass port. When the bypass port is open, the pressurized gas in the air channel enters the assembly chamber through the bypass port, and then enters the connecting chamber through the middle hole in sequence, and finally is ejected through the injection hole.

[0013] Preferably, the spiral ribs are arranged in multiple stages, and the spiral ribs of adjacent stages are staggered in the circumferential direction.

[0014] Preferably, the spindle-shaped adjusting cone is a detachable structure that is symmetrical from left to right and connected by connecting bolts, and is composed of two radially divided half-cones joined together.

[0015] Preferably, the inner walls of the two semi-cones are provided with cavities, and an isolation inner sleeve is provided in the cavity. The outer wall of the isolation inner sleeve and the inner wall of the cavity form a communicating chamber.

[0016] The inner sleeve of the isolation sleeve forms an assembly chamber, and a central hole is opened on the inner sleeve to connect the assembly chamber and the connecting chamber.

[0017] Preferably, the pneumatic flow channel switching mechanism includes a sealing member and an electric push rod for driving the sealing member to move;

[0018] The closure includes a wear-resistant elastic sealing ring sleeved on the outside of the central support shaft and a rigid support ring disposed on the outer periphery of the wear-resistant elastic sealing ring.

[0019] An isolation plate is fixedly installed inside the assembly chamber, the rigid support ring is movably sleeved in the isolation plate, and the electric push rod is connected to the rigid support ring to drive the rigid support ring to move axially.

[0020] The rigid support ring and the wear-resistant elastic sealing ring close the bypass port at the first position and open the bypass port at the second position.

[0021] Preferably, the injection hole is located on the lower outer side of the spindle-shaped adjusting cone, and the injection direction of the injection hole has a tangential component and an upward tilt angle, so as to form a spiral jet airflow that adheres to the wall and rises within the diffuser section.

[0022] Preferably, it also includes an intake regulating mechanism, which is located at the bottom of the central support shaft and includes a retractable flow-limiting column, and the intake port is provided with a reduction cavity.

[0023] The intake adjustment mechanism includes a storage cavity at the bottom of the central support shaft, a push rod movably sleeved in the storage cavity, and a spring connected to the push rod.

[0024] The push rod has a push rod portion that extends into the air passage and is dynamically sealed and slidably sleeved in the air passage, and the lower end of the push rod constitutes a flow-limiting column;

[0025] When the pressure of the gas in the airway increases, the push rod moves downward against the elastic force of the spring, causing the flow-limiting column to be inserted downward to reduce the cavity and change the air intake flow area.

[0026] Preferably, the pneumatic flow channel switching mechanism further includes an auxiliary clamping component, which includes a horizontal sleeve and a clamping column elastically sleeved in the horizontal sleeve by two springs; the horizontal sleeve is fixed on the inner wall of the isolation inner sleeve, the connecting pipe is filled with a hydraulic transmission medium, and an adapter hole opposite to the clamping column is opened on the outer side of the central support shaft. The adapter hole communicates with the air channel and is located on the radial outer side of the push rod.

[0027] The auxiliary clamping component also includes a connecting pipe disposed at the top of the transverse sleeve, a sealing plug disposed inside the connecting pipe, and a linkage push rod connected to the sealing plug.

[0028] The top of the linkage push rod is located on the movement path of the rigid support ring, so that the rigid support ring pushes the linkage push rod while moving to open the bypass port, thereby compressing the hydraulic transmission medium in the connecting pipe through the sealing plug and driving the clamping column to extend into the adapter hole to clamp and fix the push rod part of the intake adjustment mechanism.

[0029] Preferably, the control assembly includes a hydraulic push rod disposed at the top of the top cylinder, a horizontal plate connected to the free end of the hydraulic push rod and fixed to the top of the central support shaft, and a fixed sleeve fixedly fitted to the top of the top cylinder.

[0030] The central support shaft is slidably and sealingly connected to the fixed sleeve.

[0031] An air inlet is provided on the outer side of the central support shaft, and the air inlet is connected to the air passage;

[0032] The control component also includes an air pump, the air pump's outlet being connected to the interior of the fixed sleeve to inject pressurized gas into the air passage through the air inlet.

[0033] Preferably, the bottom of the air inlet is provided with an openable / closable opening / closable port;

[0034] The control component is configured to intermittently inject pressurized gas into the airway to form a high-pressure pulsed airflow, and when the bypass port is open, the high-pressure pulsed airflow is sprayed through the injection hole into the diffuser section cavity region.

[0035] The outer wall of the top cylinder is provided with a deacidification powder injection inlet, which is connected to an external deacidification powder supply unit.

[0036] The beneficial effects of this invention are as follows:

[0037] 1. This invention constructs a spiral flow channel with a continuously variable flow cross-section by coupling the central spindle-shaped regulating cone with the multi-stage spiral ribs on the inner wall of the diffuser section. As the spindle-shaped regulating cone descends axially, the flow channel cross-section contracts, forcing the airflow to change from axial flow to strong swirling flow along the wall. This not only solves the problem of powder collapse caused by insufficient turbulence intensity in the diffuser section under low load conditions, but also extends the residence time of the deacidification powder in the tower by utilizing enhanced centrifugal force, strengthening gas-solid contact and mixing, thereby stably ensuring deacidification efficiency and reducing the risk of ammonia escape under varying operating conditions.

[0038] 2. This invention achieves controllable switching between "axial drive" and "radial injection" functions of a single air source through a pneumatic flow channel switching mechanism integrated inside the central support shaft. The axial displacement of the rigid support ring controls the opening and closing of the bypass port. When the bypass port is open, the pressurized gas in the air channel is directly introduced into the internal chamber of the spindle-shaped adjusting cone and ejected at high speed from the injection hole. Without the need to add an external purging pipeline, in-situ pulse disturbance and self-cleaning of the easily dust-accumulating area of ​​the diffuser section are achieved, simplifying the internal structure of the tower and avoiding the failure risk of complex pipelines in high-temperature corrosive environments.

[0039] 3. This invention constructs a mechanical-hydraulic linkage mechanism of "jet triggering - air intake locking" through auxiliary clamping components, which solves the problem of pressure interference when sharing air passages. At the moment when the pneumatic flow channel switching mechanism moves down to open the bypass port for pressure relief jetting, the rigid support ring synchronously presses the linkage push rod, which drives the clamping column through hydraulic transmission to physically lock the bottom air intake adjustment mechanism. This ensures that the bottom air intake speed control state is forcibly fixed when the system is performing pulse cleaning or disturbance, eliminating the hidden danger of malfunction at the air intake end caused by air passage pressure fluctuations, and realizing the control and processing of cleaning disturbances and stable air intake.

[0040] 4. This invention establishes an adaptive compensation mechanism for the intake airflow rate by coordinating the intake regulating mechanism with the pressure response of the reduction tube. The air pressure in the central air channel drives the flow-limiting column to be inserted into the reduction tube, artificially reducing the flow area of ​​the intake port. Under the condition of low total intake volume, this structure can maintain a high kinetic energy jet at the inlet, ensuring sufficient momentum to lift and disperse the deacidification powder, preventing the powder from accumulating or blocking at the bottom air inlet of the tower, and ensuring the continuous and stable operation of the system within a wide load range. Attached Figure Description

[0041] Figure 1 is a schematic diagram of the connection of this flue gas treatment system;

[0042] Figure 2 is an overall schematic diagram of the present invention;

[0043] Figure 3 is a cross-sectional view of the present invention;

[0044] Figure 4 is a cross-sectional view of the tower body of the present invention;

[0045] Figure 5 is an exploded view of the spindle-shaped adjusting cone and spiral rib of the present invention;

[0046] Figure 6 is a schematic diagram of the control component of the present invention;

[0047] Figure 7 is a cross-sectional view of the spindle-shaped adjusting cone and the central support shaft of the present invention;

[0048] Figure 8 is a cross-sectional view of the control component and the central support shaft of the present invention;

[0049] Figure 9 is a cross-sectional view of the spindle-shaped adjusting cone of the present invention;

[0050] Figure 10 is a schematic diagram of the intake adjustment mechanism of the present invention;

[0051] Figure 11 is a schematic diagram of the closure component of the present invention;

[0052] Figure 12 is a cross-sectional view of the auxiliary clamping component of the present invention.

[0053] In the diagram: 1. Tower body; 101. Top cylinder; 102. Air inlet; 103. Diffuser section; 2. Spiral rib; 3. Central support shaft; 4. Air passage; 5. Spindle-shaped adjusting cone; 6. Control assembly; 601. Hydraulic push rod; 602. Horizontal plate; 603. Fixing sleeve; 604. Air pump; 7. Assembly chamber; 8. Connecting chamber; 9. Intermediate hole; 10. Injection hole; 11. Sealing component; 1101. Wear-resistant elastic sealing ring; 1102. Rigid support ring; 12. Bypass port; 13. Isolation inner sleeve; 14. 15. Electric push rod; 16. Isolation plate; 17. Reduction cavity; 18. Intake regulating mechanism; 19. Storage cavity; 10. Push plug rod; 11. Spring 1; 12. Auxiliary clamping component; 13. Horizontal sleeve; 14. Spring 2; 15. Clamping column; 16. Connecting pipe; 17. Sealing plug; 18. Linkage push rod; 19. Adaptor hole; 20. Air inlet; 21. Air inlet pipeline; 22. Conducting pipeline; 23. Catalytic chamber; 24. Discharge pipeline; 25. Powder injection inlet. Detailed Implementation

[0054] As shown in Figure 1, the dry desulfurization tower of the present invention is installed in a flue gas treatment system. The system flue gas enters the inlet 102 of the tower body 1 of the present invention through the inlet pipe 21. After mixing and reacting with the desulfurization powder in the tower body 1, it enters the catalytic chamber 23 through the connecting pipe 22 for further treatment, and is finally discharged through the outlet pipe 24. It should be understood that the inlet pipe 21, connecting pipe 22, catalytic chamber 23 and outlet pipe 24 shown in Figure 1 are only used to illustrate the connection position and material flow of the dry desulfurization tower of the present invention in the system. Except for the dry desulfurization tower of the present invention, the inlet pipe, connecting pipe, catalytic chamber and outlet pipe can all be implemented by existing technology, and their specific structural form, arrangement and parameter selection do not constitute a limitation of the present invention.

[0055] As shown in Figures 1 to 12, this embodiment of the invention provides a dry desulfurization tower for flue gas treatment to prevent ammonia escape in tail gas. The tower includes a tower body 1, which comprises a top cylinder 101, an inlet 102 located at the lower part of the tower body 1, and a diffuser section 103 connecting the inlet 102 and the top cylinder 101. Multiple spiral ribs 2, distributed circumferentially and spirally rising axially, are fixedly provided on the inner wall of the diffuser section 103. A central support shaft 3, capable of axially lifting and lowering, is provided on the central axis of the diffuser section 103. A through-flow air passage 4 is provided inside the central support shaft 3. A spindle-shaped adjusting cone 5 is sleeved on the outer side of the central support shaft 3. The spindle-shaped adjusting cone 5 and the spiral ribs 2 define the spiral flow channel, and the spindle-shaped adjusting cone 5 moves axially with the central support shaft 3 to adjust the equivalent flow cross-sectional area of ​​the spiral flow channel. A control component 6 is provided at the top of the top cylinder 101 to drive the central support shaft 3 to lift and lower and supply pressurized gas to the air passage 4. The spindle-shaped adjusting cone 5 has an assembly chamber 7 and a connecting chamber 8 inside, which are connected by a central hole 9. The outer wall of the spindle-shaped adjusting cone 5 is provided with a jet hole 10 that communicates with the connecting chamber 8. It also includes a pneumatic flow channel switching mechanism. A bypass port 12 that communicates with the air passage 4 is provided on the outer side of the central support shaft 3. The pneumatic flow channel switching mechanism is located in the assembly chamber 7 and is used to control the opening and closing of the bypass port 12. When the bypass port 12 is open, the pressurized gas in the air passage 4 enters the assembly chamber 7 through the bypass port 12, and then enters the connecting chamber 8 through the central hole 9 in sequence, and finally is ejected through the jet hole 10.

[0056] In this embodiment, the inner wall of the diffuser section 103 of the tower body 1 is provided with a spiral rib 2, which, together with the spindle-shaped adjusting cone 5 on the central support shaft 3, defines a spiral flow channel with a continuously adjustable flow cross-section. The flow field adjustment logic of this embodiment is to use the "approach of the solid boundary" to "force the reconstruction of the streamline": Under the full load (high flue gas volume) condition of the boiler, the control component 6 drives the central support shaft 3 to move upward, the spindle-shaped adjusting cone 5 moves away from the spiral rib 2, the cross-section of the spiral flow channel increases, and the system operates with low resistance; Under the low load (low flue gas volume) or the condition that requires enhanced deacidification reaction, the spindle-shaped adjusting cone 5 moves downward, and its smooth outer wall approaches the inner edge of the spiral rib 2. This action produces a dual physical effect: First, the physical flow area is significantly reduced. According to the continuity equation, this forces the airflow velocity to maintain a high speed that can support the deacidification powder, overcoming the risk of "bed collapse" and powder accumulation caused by insufficient kinetic energy in dry towers under low loads. Second, the sidewall of the spindle-shaped regulating cone 5 closes the straight-through area in the center of the diffuser section, forcing all airflow into the deep groove guide zone formed by the spiral ribs 2. This forces the original axial flow from bottom to top into a strong swirling flow that adheres to the wall. The centrifugal force generated by this strong swirling flow field "locks" large deacidification agent particles in the reaction zone near the tower wall, significantly extending the gas-solid contact time and solving the problem of insufficient reaction in short-process deacidification towers.

[0057] Specifically, in terms of thermal management and power supply, the inner wall of the spindle-shaped adjusting cone 5 is provided with a heat-insulating lining composed of nano-aerogel felt or multi-layer mica board, constructing a thermal resistance barrier between the external connecting chamber 8 and the internal assembly chamber 7. More importantly, this embodiment fully utilizes the compressed air introduced into the air passage 4 as a cold source. By setting a micro-sweeping air channel between the air passage 4 and the assembly chamber 7 (or utilizing the micro-leakage of the bypass port 12 sealing pair), the low-temperature compressed air forms a continuous positive pressure purging cycle in the assembly chamber 7, utilizing the heat absorption characteristics of gas expansion to convert electricity into heat. The operating temperature of the moving push rod 14 is controlled within the allowable range of the insulation class. At the same time, the inner wall of the central support shaft 3 is integrated with an independent rigid cable conduit to physically isolate the power supply cable from the high-pressure airflow. After the cable is introduced into the assembly chamber 7, it is connected to the electric push rod 14 through a high-temperature resistant sealed gland and a flexible metal armored hose. The flexible hose is reserved in a "U" shape in the cavity, and its deformation capability is used to adaptively compensate for the axial displacement of the electric push rod 14 when it moves with the rigid support ring 1102, thereby solving the power supply problem of high-temperature moving parts without compromising airtightness.

[0058] Regarding the anti-interference aspect of hydraulic linkage, in response to the potential issue of thermal expansion of the hydraulic medium volume caused by the device transitioning from cold start to high-temperature operation, this embodiment employs a dual filtration mechanism of "medium buffer + force threshold" for the auxiliary clamping component 18: the connecting pipe 1804 is filled with high-temperature resistant modified silicone oil and a small amount of inert gas space is reserved (or a gas-liquid two-phase transmission medium is used). Utilizing the compressibility of the gas as a "natural thermal expansion accumulator," when the hydraulic transmission medium undergoes slow and slight expansion due to heating, it preferentially compresses the internal microbubbles to reduce the static pressure within the pipeline; correspondingly, the spring 1802 on the clamping column 1803 is set to have a high preload threshold greater than the static thrust of thermal expansion. This design ensures that during normal high-temperature operation, the static pressure generated by thermal expansion is absorbed by the air bubble and remains below the spring threshold, keeping the clamping column 1803 silent. However, at the moment of pulse triggering, the dynamic pressure pulse generated by the mechanical impact of the rigid support ring 1102 on the linkage push rod 1806 far exceeds the aforementioned threshold, instantly breaking through the resistance to forcefully lock the clamping column 1803. This completely eliminates the "thermal lock-up" risk of the closed hydraulic system in a wide temperature range environment, ensuring the accurate execution of the linkage logic.

[0059] Among them, the spiral rib 2 is set in multiple stages, and the spiral rib 2 of adjacent stages is staggered in the circumferential direction. The spindle-shaped adjusting cone 5 is a detachable structure that is symmetrical from left to right and connected by connecting bolts. It is composed of two half cones that are divided radially and joined together. The inner wall of each half cone is provided with a cavity. An isolation inner sleeve 13 is provided in the cavity. The outer wall of the isolation inner sleeve 13 and the inner wall of the cavity form a communicating chamber 8. The interior of the isolation inner sleeve 13 forms an assembly chamber 7, and the middle hole 9 is opened on the isolation inner sleeve 13 to connect the assembly chamber 7 and the communicating chamber 8.

[0060] This embodiment employs a dual-layer assembly logic of "outer shell protection + inner skeleton sealing" for the spindle-shaped adjusting cone 5. The spindle-shaped adjusting cone 5 is composed of two left and right semi-cones joined together, and a high-temperature resistant sealing gasket (or labyrinth-type sealing strip) is provided at the joint between the two semi-cones. Together with the pre-tightening force of the connecting bolts, it forms the first airtight defense line to prevent the direct intrusion of external dust-laden fumes. More importantly, a complete isolation inner sleeve 13 is set up inside as the core skeleton. The isolation inner sleeve 13 is welded, and its outer wall and the inner wall of the semi-cones form a connected cavity 8. Its interior forms an independent assembly cavity 7. By utilizing the integrity of the isolation inner sleeve 13's own structure (without axial splicing seams), an absolute second sealing boundary is constructed.

[0061] The pneumatic flow channel switching mechanism includes a sealing member 11 and an electric push rod 14 for driving the sealing member 11 to move. The sealing member 11 includes a wear-resistant elastic sealing ring 1101 sleeved on the outside of the central support shaft 3 and a rigid support ring 1102 disposed on the outer periphery of the wear-resistant elastic sealing ring 1101. An isolation plate 15 is fixedly provided inside the assembly chamber 7. The rigid support ring 1102 is movably sleeved in the isolation plate 15. The electric push rod 14 is connected to the rigid support ring 1102 to drive the rigid support ring 1102 to move axially. The rigid support ring 1102 and the wear-resistant elastic sealing ring 1101 close the bypass port 12 in the first position and open the bypass port 12 in the second position.

[0062] In this embodiment, "dual-mode reuse of a single airway" is achieved within the central support shaft 3. The pneumatic flow channel switching mechanism is located within the assembly chamber 7. The sealing component 11 (including the wear-resistant elastic sealing ring 1101 and the rigid support ring 1102) is driven by the electric push rod 14 to move axially. Its operation logic and sealing guarantee are as follows: Under normal conditions, the sealing component 11 is in the upper position, and the wear-resistant elastic sealing ring 1101 blocks the bypass port 12. At this time, the airway 4 is a closed pipeline, which is only used to transmit pressure signals to the bottom air intake adjustment mechanism. When dust removal or disturbance is required, the electric push rod 14 drives the sealing component 11 to move downward. The wear-resistant elastic sealing ring 1101 slides over and opens the bypass port 12. At this time, the high-pressure gas accumulated in the airway 4 is instantly released into the assembly chamber 7 through the bypass port 12, then enters the connecting chamber 8 through the intermediate hole 9, and finally is ejected at high speed through the injection hole 10 at an angle with a tangential component. The compensation logic for seal wear is as follows: The wear-resistant elastic sealing ring 1101 is limited by the rigid support ring 1102, which forms a "scraper effect" on the surface of the central support shaft 3 during movement, which can remove a small amount of dust accumulated on the shaft surface and prevent jamming; and when the bypass port 12 is opened, the airflow direction is a high-speed positive pressure jet from the inside to the outside, forming a natural air curtain barrier, which effectively prevents external dust from flowing back into the air passage at the moment of switching. In addition, the isolation plate 15 isolates the upper and lower chambers in the assembly chamber 7, and further isolates and protects the auxiliary clamping parts 18 in the lower chamber.

[0063] The injection hole 10 is located on the lower outer side of the spindle-shaped adjusting cone 5, and the injection direction of the injection hole 10 has a tangential component and an upward tilt angle, so as to form a spiral jet airflow that adheres to the wall and rises within the diffuser section 103.

[0064] In this embodiment, the injection hole 10 is located in the windward area of ​​the lower part of the contraction section of the spindle-shaped adjusting cone 5, and its injection axis is specially designed to have a tangential component (such as an angle of 15°-30°) in the direction of airflow rotation and an upward tilt angle (such as an elevation angle of 30°-60°) to overcome gravity. This design uses the tangential component to allow the high-pressure pulse airflow to carry the initial angular momentum and seamlessly merge into the mainstream swirling flow field to accelerate the boundary layer. The upward tilt angle gives the powder agglomerates a vertical lifting force, thereby synthesizing a high-speed rotating and upward flowing wall-adhering jet layer on the inner wall surface of the diffuser section 103. This jet layer is like a "pneumatic spiral scraper", which can effectively peel off the attached deposits and blow them back to the mainstream reaction zone while preventing wet powder from sticking to the wall. This achieves in-situ active cleaning and flow field kinetic energy compensation for blind areas prone to dust accumulation.

[0065] The system also includes an intake regulating mechanism 17, which is located at the bottom of the central support shaft 3 and includes a retractable flow-limiting column. The intake port 102 has a reduction chamber 16 inside. The intake regulating mechanism 17 includes a storage cavity 1701 at the bottom of the central support shaft 3, a push rod 1702 movably sleeved in the storage cavity 1701, and a spring 1703 connected to the push rod 1702. The push rod 1702 has a push rod portion extending into the air passage 4 and is dynamically and slidably sleeved in the air passage 4. The lower end of the push rod 1702 forms a flow-limiting column. When the pressure of the pressurized gas in the air passage 4 increases, the push rod 1702 overcomes the elastic force of the spring 1703 and moves downward, causing the flow-limiting column to insert downward into the reduction chamber 16 to change the intake flow area. The pneumatic flow channel switching mechanism also includes an auxiliary clamping member 18, which includes a horizontal sleeve 1801 and a spring 1803. A clamping post 1803 is elastically sleeved in the transverse sleeve 1801; the transverse sleeve 1801 is fixed on the inner wall of the isolation inner sleeve 13, the connecting pipe 1804 is filled with hydraulic transmission medium, and the outer side of the central support shaft 3 is provided with an adapter hole 19 opposite to the clamping post 1803; the auxiliary clamping component 18 also includes a connecting pipe 1804 connected to the top of the transverse sleeve 1801, a sealing plug 1805 provided in the connecting pipe 1804, and a linkage push rod 1806 connected to the sealing plug 1805; the top end of the linkage push rod 1806 is located on the movement path of the rigid support ring 1102, so that the rigid support ring 1102 pushes the linkage push rod 1806 while moving to open the bypass port 12, thereby compressing the hydraulic transmission medium in the connecting pipe 1804 through the sealing plug 1805 and driving the clamping post 1803 to extend into the adapter hole 19 to clamp and fix the push rod part of the air intake adjustment mechanism 17.

[0066] This embodiment features an intake adjustment mechanism 17 at the bottom of the central support shaft 3. When the pressure changes within the air passage 4, the push rod 1702 overcomes the spring force of the spring 1703 to generate axial displacement. The lower end of the push rod forms a flow-limiting column that can be retractably inserted into the reduced cavity 16 within the intake port 102. This adaptively adjusts the intake flow area, achieving stable matching of the inlet air volume or velocity. It overcomes the instability of the flow field caused by insufficient inlet momentum or pressure fluctuations under varying operating conditions, and avoids the uncertainty caused by the lag in manual or external actuator adjustments. Simultaneously, a pneumatic flow channel switching mechanism is introduced... The auxiliary clamping component 18, along with the synchronous pressure of the rigid support ring 1102 when the bypass port 12 is opened, triggers the linkage push rod 1806. The hydraulic transmission medium in the connecting pipe 1804 is compressed by the sealing plug 1805, driving the clamping column 1803 to extend into the adapter hole 19 to clamp and fix the push rod part of the intake regulating mechanism 17. This achieves the linkage consistency of "bypass injection or pressure relief trigger - intake flow restriction lock", overcomes the problem of flow restriction column shaking, swaying or insertion depth drift caused by sudden change in airway pressure at the moment of bypass opening, and avoids control distortion caused by mutual interference between two sets of action links in the same airway.

[0067] By employing a preferred sealing and guiding method, the push rod portion of the push rod 1702 maintains dynamic sealing and stable guidance when sliding within the air passage 4, thereby reducing air leakage and suppressing jamming caused by dust-laden media entering the sliding fit gap. By preferably using a tapered or stepped shape for the flow-limiting column and limiting its maximum insertion stroke, the change in the air intake flow area is controllable, avoiding a sudden increase in pressure drop due to excessive insertion. By forming a reliable hydraulic transmission chamber between the sealing plug 1805 and the connecting pipe 1804, and by implementing dustproof isolation and limiting cooperation at the mating point between the adapter hole 19 and the clamping column 1803, the clamping force output is stable, ensuring that the push rod portion does not loosen or rebound in the locked state, thereby ensuring the consistency and repeatability of the two actions of air intake regulation and bypass injection during the linkage process.

[0068] The control component 6 includes a hydraulic push rod 601 mounted on the top of the top cylinder 101, a horizontal plate 602 connected to the free end of the hydraulic push rod 601 and fixed to the top of the central support shaft 3, and a fixed sleeve 603 fixedly sleeved on the top of the top cylinder 101; the central support shaft 3 and the fixed sleeve 603 are slidably sealed together; an air inlet 20 is provided on the outside of the central support shaft 3, and the air inlet 20 is connected to the air passage 4; the control component 6 also includes an air pump 604, the air outlet of the air pump 604 is connected to the inside of the fixed sleeve 603, so as to inject pressurized gas into the air passage 4 through the air inlet 20.

[0069] In this embodiment, the control component 6 is arranged on the top of the top cylinder 101. The hydraulic push rod 601 and the horizontal plate 602 drive the central support shaft 3 to move axially within the fixed sleeve 603. The central support shaft 3 and the fixed sleeve 603 are connected by a sliding seal, which ensures that the central support shaft 3 can be raised and lowered smoothly while maintaining the airtight isolation at the top. At the same time, an air inlet 20 connected to the air passage 4 is set on the outside of the central support shaft 3, and the air outlet of the air pump 604 is connected to the inside of the fixed sleeve 603 so that the pressurized gas is stably injected into the air passage 4 through the air inlet 20. This realizes the integration of "axial drive adjustment" and "coaxial air supply injection", which overcomes the unstable air supply caused by the easy twisting and leakage of the interface of the traditional external hose. It also avoids the external medium from entering from the top gap in the dusty environment, which would affect the pressure establishment and operation consistency of the air passage 4.

[0070] By adopting a preferred sliding seal and guide engagement method (for example, setting a sealing ring mounting groove and configuring a wear-resistant guide bushing on the inner wall of the fixed sleeve 603, so that the central support shaft 3 can obtain both sealing and guiding constraints during reciprocating movement), the wear of the sealing surface, air leakage, and pressure reduction caused by the leakage of pressurized gas caused by axial reciprocating movement are avoided; and it is preferable to form an annular gas distribution space inside the fixed sleeve 603 to be aligned and connected with the air inlet 20, thereby ensuring that the pressurized gas output by the air pump 604 can still reliably enter the air passage 4 at different axial positions, avoiding gas supply interruption or pulsation distortion caused by position changes.

[0071] As one implementation method, the outlet end of the air pump 604 can be connected in series with a pulse solenoid valve or equipped with a pressure accumulator to form a repeatable intermittent pulse air supply under the action of a control signal.

[0072] The air inlet 102 has an openable and closable opening at its bottom; the control component 6 is configured to intermittently inject pressurized gas into the air passage 4 to form a high-pressure pulse airflow, and when the bypass port 12 is open, the high-pressure pulse airflow is sprayed into the inner cavity area of ​​the diffuser section 103 through the injection hole 10; the outer wall of the top cylinder 101 is provided with a deacidification powder injection inlet 25, which is connected to an external deacidification powder supply unit.

[0073] This embodiment sets an openable and closable port at the bottom of the inlet 102 and intermittently injects pressurized gas into the air passage 4 through the control component 6 to form a high-pressure pulse airflow. When the bypass port 12 is opened, the high-pressure pulse airflow is directed through the injection hole 10 to the inner cavity area of ​​the diffuser section 103. This combines "inlet opening / closing / isolation" with "pulse injection disturbance" to achieve periodic strengthening and disturbance renewal of the local flow field in the diffuser section 103. This overcomes the problem that continuous low-flow-rate blowing is difficult to form effective disturbance under varying operating conditions and is prone to powder accumulation or collapse on the wall. It also avoids the acid removal efficiency fluctuation and local blockage risk caused by insufficient disturbance at low load due to relying solely on the swirling intensity of the main airflow.

[0074] By adopting a preferred opening and closing structure and pulse injection strategy, the high-pressure pulse airflow can be stably established when the bypass port 12 is opened and form repeatable injection momentum through the injection hole 10, ensuring the stability of the disturbance effect. At the same time, the outer wall of the top cylinder 101 is provided with a deacidification powder injection inlet 25 and connected to the external deacidification powder supply unit, so that the deacidification powder can enter in time and be fully mixed with the flue gas under the flow field conditions formed by the injection disturbance, avoiding reaction lag and powder enrichment caused by a single powder supply position or insufficient mixing, thereby improving the uniformity of gas-solid contact and the continuity of the deacidification process under variable operating conditions.

[0075] In this embodiment, the deacidification powder inlet 25 is connected to an external deacidification powder supply unit. The external deacidification powder supply unit can be implemented using existing technology, such as including one or more of a powder storage bin, a metering feeding assembly, and a pneumatic conveying / screw conveying assembly, used to continuously or intermittently feed the deacidification powder into the deacidification powder inlet 25 according to a set dosage. The specific structure, model, and control method of the external deacidification powder supply unit can be selected according to the on-site working conditions and do not constitute a limitation of the present invention.

[0076] Working principle and usage process of this invention:

[0077] Startup and flow field settings:

[0078] When started, the control component 6 drives the hydraulic push rod 601 to move. The hydraulic push rod 601 drives the central support shaft 3 to move axially within the fixed sleeve 603 through the horizontal plate 602, so that the spindle-shaped adjusting cone 5 sleeved on the outside of the central support shaft 3 rises and falls synchronously. The operator sets the initial position of the spindle-shaped adjusting cone 5 according to the flue gas flow and pressure drop requirements.

[0079] Flue gas enters and forms a spiral upflow:

[0080] After entering the inlet 102 through the inlet pipe 21, the flue gas enters the diffuser section 103. The spiral ribs 2 on the inner wall of the diffuser section 103 guide the incoming flue gas circumferentially, and the flue gas forms a spiral upward mainstream along the inner wall of the diffuser section. The spindle-shaped regulating cone 5 and the spiral ribs 2 together define the spiral flow channel. When the spindle-shaped regulating cone 5 moves downward along the axis, the flow cross-sectional area of ​​the spiral flow channel decreases, and the mainstream gradually changes from axial flow to strong swirling flow attached to the wall.

[0081] Powder injection and gas-solid contact process:

[0082] The deacidification powder enters the inner cavity of the top cylinder 101 through the deacidification powder injection inlet 25 from the external deacidification powder supply unit. After entering, the powder is entrained by the spiral rising mainstream and migrates with the flow, continuously contacting the flue gas in the spiral channel. After the gas-solid mixture flows into the upper space of the top cylinder 101, it is transported to the catalytic chamber 23 through the connecting pipe 22. The flue gas treated in the catalytic chamber 23 is discharged through the discharge pipe 24 or enters the subsequent treatment unit.

[0083] Switching between pressurized gas input and injection pathways:

[0084] The air pump 604 delivers pressurized gas into the fixed sleeve 603, and then into the air passage 4 inside the central support shaft 3 through the air inlet 20. When it is necessary to disturb or purge the tower, the electric push rod 14 drives the rigid support ring 1102 and the wear-resistant elastic sealing ring 1101 to move axially, so that the bypass port 12 switches from the closed state to the open state. At this time, the pressurized gas in the air passage 4 enters the assembly chamber 7 through the bypass port 12, then enters the connecting chamber 8 through the intermediate hole 9, and finally is injected into the diffuser section 103 through the injection hole 10. The inner cavity, the injection state can be intermittently performed according to the set pulse rhythm; when the bypass port 12 is opened, the auxiliary clamping member 18 is triggered in linkage with the downward movement of the rigid support ring 1102: the rigid support ring 1102 pushes the linkage push rod 1806 to compress the hydraulic transmission medium in the connecting pipe 1804, thereby driving the clamping column 1803 to extend into the adapter hole 19 and clamp the push rod part of the push plug rod 1702 of the intake adjustment mechanism 17, so that the intake adjustment mechanism remains fixed in this stage;

[0085] Intake regulation under low inlet flow conditions:

[0086] When it is necessary to change the flow area at the intake end, the flow-limiting column of the intake regulating mechanism 17 moves downward under the action of pressurized gas and inserts into the reduction tube 16, thereby changing the flow state at the intake port 102; its push rod is dynamically sealed and slidably sleeved in the air passage 4, the air pressure in the air passage increases and pushes the push rod to move downward, and drives the push rod 1702 to move downward against the elastic force of the spring-1703, so that the flow-limiting column is inserted into the reduction tube 16;

[0087] Dust removal procedure:

[0088] When dust removal is required, open the opening and closing port at the bottom of the air inlet 102 to remove dust. During the dust removal stage, the pulse jet state of the injection hole 10 can be maintained as needed to keep the airflow turbulence and air replenishment process in the inner cavity of the diffuser section 103. After the dust removal is completed, close the opening and closing port and restore normal operation.

Claims

1. A dry desulfurization tower for flue gas treatment to prevent ammonia escape in tail gas, comprising a tower body (1), characterized in that: The tower body (1) includes a top cylinder (101), an air inlet (102) located at the lower part of the tower body (1), and a diffuser section (103) connecting the air inlet (102) and the top cylinder (101); the inner wall of the diffuser section (103) is fixedly provided with multiple spiral ribs (2) distributed circumferentially and spirally rising axially; a central support shaft (3) that can be raised and lowered axially is provided on the central axis of the diffuser section (103), and a through air passage (4) is provided inside the central support shaft (3); a spindle-shaped adjusting cone (5) is sleeved on the outside of the central support shaft (3), and the spindle-shaped adjusting cone (5) and the spiral ribs (2) define the spiral flow channel, and move axially with the central support shaft (3) to adjust the equivalent flow cross-sectional area of ​​the spiral flow channel; a control component (6) is provided at the top of the top cylinder (101) for driving the middle The central support shaft (3) is raised and lowered and supplies pressurized gas to the air passage (4); the spindle-shaped adjusting cone (5) is provided with an assembly chamber (7) and a connecting chamber (8), which are connected by a middle hole (9), and the outer wall of the spindle-shaped adjusting cone (5) is provided with a jet hole (10) connected to the connecting chamber (8); it also includes a pneumatic flow channel switching mechanism, and the outer side of the central support shaft (3) is provided with a bypass port (12) connected to the air passage (4). The pneumatic flow channel switching mechanism is located in the assembly chamber (7) and is used to control the opening and closing of the bypass port (12). When the bypass port (12) is open, the pressurized gas in the air passage (4) enters the assembly chamber (7) through the bypass port (12), and then enters the connecting chamber (8) through the middle hole (9) in sequence, and finally is ejected through the jet hole (10).

2. The dry desulfurization tower for flue gas treatment to prevent ammonia escape in tail gas according to claim 1, characterized in that: The spiral ribs (2) are arranged in multiple levels, and the spiral ribs (2) of adjacent levels are staggered in the circumferential direction.

3. The dry acid removal tower for flue gas treatment to prevent ammonia escape in tail gas according to claim 1, characterized in that: The spindle-shaped adjusting cone (5) is a detachable structure that is symmetrical on the left and right and connected by connecting bolts. It is composed of two radially divided half cones joined together.

4. The dry desulfurization tower for flue gas treatment to prevent ammonia escape in tail gas according to claim 1, characterized in that: The inner walls of the two semi-cones are provided with cavities, and an isolation inner sleeve (13) is provided in the cavity. The outer wall of the isolation inner sleeve (13) and the inner wall of the cavity form a communicating chamber (8). An assembly chamber (7) is formed inside the isolation inner sleeve (13), and a middle hole (9) is opened on the isolation inner sleeve (13) to connect the assembly chamber (7) and the communicating chamber (8).

5. The dry acid removal tower for flue gas treatment to prevent ammonia escape in tail gas according to claim 4, characterized in that: The pneumatic flow channel switching mechanism includes a sealing member (11) and an electric push rod (14) for driving the sealing member (11) to move; the sealing member (11) includes a wear-resistant elastic sealing ring (1101) sleeved on the outside of the central support shaft (3) and a rigid support ring (1102) disposed on the outer periphery of the wear-resistant elastic sealing ring (1101); an isolation plate (15) is fixedly provided inside the assembly chamber (7), the rigid support ring (1102) is movably sleeved in the isolation plate (15), and the electric push rod (14) is connected to the rigid support ring (1102) to drive the rigid support ring (1102) to move axially; the rigid support ring (1102) and the wear-resistant elastic sealing ring (1101) close the bypass port (12) in the first position and open the bypass port (12) in the second position.

6. The dry desulfurization tower for flue gas treatment to prevent ammonia escape in tail gas according to claim 5, characterized in that: The injection hole (10) is located on the lower outer side of the spindle-shaped adjusting cone (5), and the injection direction of the injection hole (10) has a tangential component and an upward tilt angle, so as to form a spiral jet airflow that adheres to the wall and rises in the diffuser section (103).

7. The dry desulfurization tower for flue gas treatment to prevent ammonia escape in tail gas according to claim 6, characterized in that: It also includes an intake regulating mechanism (17), which is located at the bottom of the central support shaft (3) and includes a retractable flow-limiting column. The intake port (102) is provided with a reduction chamber (16). The intake regulating mechanism (17) includes a storage chamber (1701) opened at the bottom of the central support shaft (3), a push rod (1702) movably sleeved in the storage chamber (1701), and a spring (1703) connected to the push rod (1702). The push rod (1702) has a push rod part that extends into the air passage (4) and is dynamically sealed and slidably sleeved in the air passage (4). The lower end of the push rod (1702) constitutes a flow-limiting column. When the pressure of the gas in the air passage (4) increases, the push rod (1702) overcomes the elastic force of the spring (1703) and moves downward, so that the flow-limiting column is inserted downward into the reduction chamber (16) to change the intake flow area.

8. The dry desulfurization tower for flue gas treatment to prevent ammonia escape in tail gas according to claim 7, characterized in that: The pneumatic flow channel switching mechanism also includes an auxiliary clamping component (18), which includes a horizontal sleeve (1801) and a clamping column (1803) elastically sleeved in the horizontal sleeve (1801) by a spring (1802); the horizontal sleeve (1801) is fixed on the inner wall of the isolation inner sleeve (13), the connecting pipe (1804) is filled with hydraulic transmission medium, and the outer side of the central support shaft (3) is provided with an adapter hole (19) opposite to the clamping column (1803), the adapter hole (19) is connected to the air channel (4) and is located on the radial outer side of the push rod; the auxiliary clamping component (18) also includes a component connected to the horizontal sleeve. The connecting pipe (1804) at the top of the pipe (1801), the sealing plug (1805) set in the connecting pipe (1804), and the linkage push rod (1806) connected to the sealing plug (1805); the top of the linkage push rod (1806) is located on the movement path of the rigid support ring (1102), so that the rigid support ring (1102) pushes the linkage push rod (1806) while moving to open the bypass port (12), thereby compressing the hydraulic transmission medium in the connecting pipe (1804) through the sealing plug (1805) and driving the clamping column (1803) to extend into the adapter hole (19) to clamp and fix the push rod part of the air intake adjustment mechanism (17).

9. The dry desulfurization tower for flue gas treatment to prevent ammonia escape in tail gas according to claim 1, characterized in that: The control component (6) includes a hydraulic push rod (601) disposed on the top of the top cylinder (101), a horizontal plate (602) connected to the free end of the hydraulic push rod (601) and fixed to the top of the central support shaft (3), and a fixed sleeve (603) fixedly sleeved on the top of the top cylinder (101); the central support shaft (3) and the fixed sleeve (603) are slidably sealed together; an air inlet (20) is provided on the outside of the central support shaft (3), and the air inlet (20) is connected to the air passage (4); the control component (6) also includes an air pump (604), the air outlet of the air pump (604) is connected to the inside of the fixed sleeve (603) to inject pressurized gas into the air passage (4) through the air inlet (20).

10. The dry desulfurization tower for flue gas treatment to prevent ammonia escape in tail gas according to claim 1, characterized in that: The bottom of the air inlet (102) is provided with an openable and closable opening; the control component (6) is configured to intermittently inject pressurized gas into the air passage (4) to form a high-pressure pulse airflow, and when the bypass port (12) is opened, the high-pressure pulse airflow is sprayed through the injection hole (10) into the inner cavity area of ​​the diffuser section (103); the outer wall of the top cylinder (101) is provided with a deacidification powder injection inlet (25), and the deacidification powder injection inlet (25) is connected to the external deacidification powder supply unit.

Images