Ammonia water denitration device and method

Abstract

The invention belongs to the technical field of flue gas purification, and discloses an ammonia water denitration device and method.The device comprises an absorption tower and a compensation assembly, the compensation assembly comprises a liquid storage tank, and the liquid storage tank is connected with a spraying medium through a liquid inlet pipeline and communicated with a spraying layer of the absorption tower through a liquid outlet pipeline; the piston is arranged in the liquid storage tank in a sliding manner and is used for dividing the liquid storage tank into a liquid storage chamber and a driving chamber; an air outlet of the air cylinder communicates with the driving cavity through an air inlet pipeline, and the air cylinder is used for driving the piston to extrude the liquid storage cavity; according to the scheme, when spraying is started, air is supplied through the air cylinder to drive the piston to slide in the liquid storage tank, so that a medium in the liquid storage cavity is squeezed, the pressure of the medium is increased, and insufficient power in the initial stage of starting of the water pump is compensated; the device solves the problems of invalid consumption of a reducing agent caused by advanced spraying of an absorption tower and flue gas escape caused by delayed spraying, and is suitable for flue gas desulfurization and denitrification in a caustic soda production process.

Description

An ammonia denitrification device and method Technical Field

[0001] This solution belongs to the field of flue gas purification technology, specifically involving an ammonia denitrification device and method. Background Technology

[0002] The flue gas produced during the caustic soda production process contains NO x Pollutants such as nitrogen oxides and nitrogen oxides exacerbate air pollution, harm the ecological environment, and endanger human health. Therefore, flue gas must be purified to meet environmental emission standards. Ammonia, as a highly efficient reducing agent, is mainly used for denitrification in flue gas purification. It can react with NO in the flue gas... x A selective reduction reaction occurs, converting harmful pollutants into harmless nitrogen and water. This process is commonly used to resolve NO in industrial flue gas. x The issue of purification.

[0003] When using ammonia water to purify flue gas, a desulfurization and denitrification absorption tower is often used. During operation, the flue gas is introduced from the bottom of the absorption tower, and then ammonia water and other reaction solutions are sprayed inside the absorption tower to react with the upward-floating flue gas and remove sulfides and nitrogen oxides from the flue gas. The sprayed water droplets can also remove dust from the flue gas.

[0004] A simultaneous flue gas desulfurization and denitrification process based on ammonia-ferrous oxalate is disclosed in the existing publication (announcement) number CN105771650A. The process includes: flue gas is pressurized and sent to a thickening tower to react with the concentrated liquid; the flue gas exiting the thickening tower is sent to an absorption tower to react with the circulating absorbent liquid sprayed from the upper spray layer of the tower in a counter-current reaction and then discharged from the top of the absorption tower; the flue gas enters the absorption tower through the flue gas inlet in the middle of the absorption tower, passes through at least one photochemical reaction layer, a packing layer and a spray layer in sequence, reacts with the circulating absorbent liquid in a counter-current reaction and then is discharged from the flue gas outlet.

[0005] For example, in the aforementioned absorption tower structure, the spraying is typically activated before the flue gas enters the absorption tower to prevent the flue gas from escaping due to lack of spraying. However, this results in the ineffective consumption of the reducing agent sprayed in advance because it does not come into contact with the flue gas. If the spraying is activated only after the flue gas enters the absorption tower, the mechanical delay caused by the pump startup means that the initial pump output pressure and the reducing agent medium flow rate cannot quickly reach the normal flow rate. In other words, the spray medium flow rate is slow during the startup phase, resulting in insufficient pressure on the spray layer. This leads to poor atomization of the spray nozzles, with some nozzles producing excessively large atomized particles and others spraying insufficient amounts. Consequently, the spray medium cannot cover the entire cross-section of the absorption tower, creating a spray blind zone. This means that some of the flue gas entering initially still cannot fully contact the spray medium, and the problem of escape still exists. Summary of the Invention

[0006] The purpose of this solution is to provide an ammonia denitrification device to solve the problems of ineffective consumption of reducing agent due to premature spraying of the absorption tower and flue gas escape due to delayed spraying.

[0007] To achieve the above objectives, this solution provides an ammonia denitrification device, including an absorption tower and a compensation component. The compensation component includes: a storage tank, which is connected to a spray medium via an inlet pipe and communicates with the spray layer of the absorption tower via an outlet pipe; a piston, which is slidably disposed within the storage tank to divide the storage tank into a storage chamber and a drive chamber; and a cylinder, whose outlet is connected to the drive chamber via an inlet pipe to drive the piston to compress the storage chamber.

[0008] The principle and effect of this scheme are as follows: The storage tank pre-stores ammonia and other spraying media. When the flue gas enters the absorption tower, the spraying process is started simultaneously. The water pump continues to replenish the spraying media into the storage tank through the inlet pipe. However, because the media pressure is low at the initial stage of pump startup, air is supplied through a cylinder to drive a piston to slide within the storage tank, thereby compressing the media in the storage chamber and increasing the media pressure. This compensates for the insufficient power of the water pump at the initial startup, avoiding ineffective consumption of the reducing agent due to premature spraying and solving the problems of poor atomization and blind spots caused by delayed spraying. After the water pump is running normally, the air supply to the storage tank is stopped. The spraying media passes through the inlet pipe, the storage tank, and the outlet pipe, finally being sprayed from the spray layer, thus desulfurizing and denitrifying the flue gas.

[0009] Furthermore, the piston is fixedly connected to a spring, and the free end of the spring is fixedly connected to the inner wall of the liquid storage tank; a one-way valve is provided on the liquid inlet pipe, and the one-way valve is directed from the liquid inlet pipe to the liquid storage tank; an electromagnetic three-way valve is provided on the air inlet pipe.

[0010] The principle and effect of this scheme are as follows: when the gas supply to the storage tank is stopped, the restoring force of the spring drives the piston to return to the initial position; the one-way valve is used to prevent the medium in the inlet pipe from flowing back when the piston squeezes the storage chamber; when the flue gas enters the absorption tower, the electromagnetic three-way valve switches to the inlet pipe conduction state to supply gas to the storage tank, and when the water pump is running normally, the electromagnetic three-way valve switches to the inlet pipe cut-off state.

[0011] Furthermore, it also includes a drive assembly for reciprocating the piston rod of the cylinder. The drive assembly includes a drive wheel and a motor. The output shaft of the motor is coaxially and fixedly connected to the drive wheel. A drive rod is coaxially and fixedly connected to the drive wheel. A rocker arm is hinged to the free end of the drive rod. The free end of the rocker arm is hinged to the piston rod.

[0012] The principle and effect of this scheme are as follows: after the motor starts, it drives the drive wheel to rotate, and the drive rod on the drive wheel moves in a circular motion. Through the cooperation with the rocker arm, the circular motion is converted into the reciprocating motion of the piston rod, thereby squeezing the gas in the cylinder chamber and discharging it from the outlet into the drive chamber, so as to drive the piston in the liquid storage tank to squeeze the liquid storage chamber.

[0013] Furthermore, it also includes a flow equalization component, which includes a flow equalization cylinder and a nozzle. The flow equalization cylinder and the nozzle are both located inside the absorption tower and on the side away from the air inlet of the absorption tower. The flow equalization cylinder is a flow equalization cylinder with openings at both ends. The flow equalization cylinder is vertically arranged and has several through flow equalization ports on the side near the air inlet. The nozzle is located below the flow equalization cylinder, and the outlet end of the nozzle opens vertically toward one end of the flow equalization cylinder. The nozzle is connected to the exhaust port of the cylinder through an air supply pipe.

[0014] The principle and effect of this solution are as follows: Since the existing absorption tower adopts a bottom-end air inlet structure, the air inlet and the tower body of the absorption tower form an "L" shape. When the flue gas in the horizontal flue enters the vertical tower body with a certain momentum, its inertia causes the mainstream area to preferentially scour the tower wall along the original flow direction (closer to the air inlet side). During the turning process, a vortex is formed at the corner, which consumes energy and hinders the flue gas from diffusing to the other side. This causes the flue gas velocity on the absorption tower side away from the air inlet to drop to a stagnant state, forming a low-speed or no-flow area (i.e., a dead zone). This results in an uneven flow field inside the absorption tower, and the contact area of ​​the spray area corresponding to the flue gas dead zone is reduced, resulting in waste of spray medium. In this scheme, the reciprocating motion of the cylinder piston rod compresses the gas in its chamber, which is then transported to the nozzle through the gas delivery pipe. The nozzle sprays the gas vertically upwards at one end of the flow equalization cylinder at a velocity higher than that of the flue gas. Based on Bernoulli's principle, a low-pressure zone is formed inside the flow equalization cylinder. Then, a portion of the flue gas in the mainstream zone (located in the middle of the absorption tower) is drawn into the flow equalization cylinder through the flow equalization port. The gas then sprayed out by the nozzle is transported upwards to the spray layer, so that flue gas also flows upwards on the side of the absorption tower away from the air inlet, reducing the influence of the flue gas dead zone and making the flue gas flow field in the absorption tower more uniform, thereby reducing the waste of spray media in the corresponding area.

[0015] Furthermore, the cylinder includes a cylinder body and a cylinder plug, the cylinder plug being slidably disposed within the cylinder body to divide the cylinder body into a first chamber and a second chamber, the exhaust port being connected to the first chamber and the exhaust port being connected to the second chamber; the cylinder body is provided with a first air inlet and a second air inlet, the first air inlet being connected to the first chamber and the second air inlet being connected to the second chamber.

[0016] The principle and effect of this scheme are as follows: the cylinder piston divides the cylinder into a first chamber and a second chamber, and air is supplied alternately through the first air inlet and the second air inlet. The piston rod drives the cylinder piston to reciprocate within the cylinder, so that the first chamber provides compression pressure to the liquid storage tank through the air outlet, while the second chamber delivers airflow to the air nozzle through the exhaust port.

[0017] Furthermore, the support plate is provided with a slide rail arranged along its length, and the support rod is slidably connected to the slide rail.

[0018] The principle and effect of this solution are as follows: the slide rail is used to provide positioning and guidance for the horizontal movement of the support rod.

[0019] Furthermore, the flow equalization assembly also includes a support plate and a support rod. The support rod is horizontally slidably mounted on the support plate. A permanent magnet is mounted on the support rod, and an electromagnet is mounted on the support plate. When the electromagnet is energized, it is used to attract the permanent magnet. A compression spring is connected to the support rod, and the free end of the compression spring is fixedly connected to the support plate. One end of the support rod passes through the absorption tower and is fixedly connected to the gas nozzle.

[0020] The principle and effect of this solution are as follows: When the absorber tower stops intake, the flue gas that enters the tower last loses its external driving force (such as a fan), causing its upward flow to slow down or even stop. This prevents it from quickly contacting the spray medium, leading to wasted spraying. Furthermore, the stagnant flue gas remains inside the tower, affecting its subsequent restart. In this solution, under normal conditions, the electromagnet is energized, attracting the permanent magnet and causing it to move the nozzle away from the air inlet, placing it on the side furthest from the inlet. When the absorber tower stops intake, the electromagnet is de-energized. After losing the electromagnet's attraction, the restoring force of the spring drives the support rod to slide horizontally along the support plate, moving the nozzle towards the air inlet. The continuously sprayed airflow from the nozzle creates an upward driving force on the last flue gas entering the tower, pushing it upward rapidly and ensuring full contact with the spray medium, thus avoiding waste of the spray medium.

[0021] Furthermore, the length of the support rod is not less than the diameter of the absorption tower.

[0022] The principle and effect of this solution is that when the support rod slides, the air nozzle can move from the side away from the air inlet to the side of the air inlet, covering the entire cross-sectional area of ​​the absorption tower.

[0023] Furthermore, a check valve is provided on the gas delivery pipeline, and the direction of conduction of the check valve is from the gas delivery pipeline to the gas nozzle.

[0024] The principle and effect of this solution are as follows: by setting a check valve, the flue gas or backflow gas at the nozzle end is prevented from flowing back into the gas supply pipe and the second chamber when the cylinder piston moves and the space of the second chamber increases and negative pressure is generated.

[0025] A method for denitrifying ammonia water, comprising the application of an ammonia water denitrification device as described, includes the following steps: Step S10: Ammonia water is pre-stored in a storage tank. Flue gas from caustic soda production is introduced into the absorption tower through the air inlet, and the spray system is started simultaneously. A water pump replenishes ammonia water to the storage tank through the inlet pipe. The electromagnetic three-way valve is switched to the air inlet pipe open state, and the drive component drives the piston rod of the cylinder to reciprocate. Air is supplied to the first chamber through the first air inlet, driving the piston to slide and squeeze the storage chamber. Ammonia water is transported to the spray layer through the outlet pipe and uniformly atomized and sprayed out. Step S20: The airflow discharged from the second chamber of the cylinder is transported to the air nozzle. The air nozzle sprays airflow, which is drawn into the mainstream flue gas through the flow equalization port and transported upward. Step S30: When the absorption tower stops supplying air, the support rod slides horizontally along the support plate, causing the air nozzle to move from the side away from the air inlet to the side of the air inlet. The air nozzle continuously sprays airflow to push the residual flue gas to continue to flow upward. Attached Figure Description

[0026] Figure 1 is a structural schematic diagram of an ammonia denitrification device of the present invention; Figure 2 is a structural schematic diagram of the compensation component, driving component and flow equalization component of the present invention; Figure 3 is a structural schematic diagram of the driving component of the present invention; Figure 4 is a structural schematic diagram of the flow equalization component of the present invention; Figure 5 is a structural schematic diagram of the air nozzle of the present invention; Figure 6 is a structural schematic diagram of the driving gear, driven gear and rotary joint of the present invention.

[0027] The reference numerals in the accompanying drawings include: absorption tower 1, air inlet 11, compensation component 2, liquid storage tank 21, liquid storage chamber 211, drive chamber 212, liquid inlet pipe 22, liquid outlet pipe 23, piston 24, cylinder 25, air outlet 251, air inlet pipe 252, piston rod 253, exhaust port 254, cylinder plug 255, first chamber 256, second chamber 257, first air inlet 258, second air inlet 259, cylinder body 2510, spring. 26. One-way valve 27. Solenoid three-way valve 28. Ammonia tank 29. Water pump 210. Spray layer 3. Spray pipe 31. Rotary joint 32. Drive assembly 4. Drive wheel 41. Motor 42. Drive rod 43. Rocker arm 44. Drive gear 45. Driven gear 46. Flow equalization assembly 5. Flow equalization cylinder 51. Flow equalization port 511. Air nozzle 52. Air supply pipe 521. Check valve 522. Support plate 53. Support rod 54. Permanent magnet 55. Electromagnet 56. Compression spring 57. Detailed Implementation

[0028] The following will describe the concept and technical effects of the present invention clearly and completely with reference to embodiments, so as to fully understand the purpose, features and effects of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are all within the scope of protection of the present invention: Embodiment 1: Please refer to Figure 1. This embodiment provides an ammonia denitrification device, suitable for caustic soda production lines containing NO. x The purification treatment of industrial flue gas can solve the problems of ineffective consumption of reducing agent due to premature spraying and flue gas escape caused by delayed spraying in existing technologies. The whole device includes an absorption tower 1, a compensation component 2, a drive component 4, and a flow equalization component 5. An air inlet 11 is provided on the bottom left side of the absorption tower 1. The air inlet 11 and the tower body of the absorption tower 1 form an L-shaped structure. A spray layer 3 is installed inside the upper part of the absorption tower 1. The spray layer 3 adopts multiple sets of atomizing nozzles.

[0029] Please refer to Figures 2 and 3. The compensation component 2 includes a storage tank 21, a piston 24, and a cylinder 25. The storage tank 21 is connected to the spray medium supply system through the inlet pipe 22. The spray medium supply system is existing technology, such as an ammonia tank 29 and a water pump 210. The inlet end of the water pump 210 is connected to the ammonia tank 29, and the outlet end of the water pump 210 is connected to the inlet pipe 22. A one-way valve 27 is installed on the inlet pipe 22. The one-way valve 27 is directed from the inlet pipe 22 to the storage tank 21, which can prevent the backflow of the medium in the storage chamber 211. A piston 24 is slidably installed inside the storage tank 21. The piston 24 is interference-fitted with the inner wall of the storage tank 21, and the piston 24 divides the storage tank 21 into a storage chamber 211 and a drive chamber 212. The storage chamber 211 is used to store ammonia water, and the drive chamber 212 is used to purge the piston 24 towards the storage chamber 211, thereby squeezing the ammonia water in the storage chamber 211. A spring 26 is fixedly connected to the lower end of the piston 24, and the free end of the spring 26 is welded and fixed to the bottom inner wall of the storage tank 21. When there is no air pressure driving the piston 24, it can drive the piston 24 to return to its initial position. The storage tank 21 is connected to the spray layer 3 through the outlet pipe 23. A flow regulating valve (not shown) is installed on the outlet pipe 23, which can be used in conjunction with the control system to adjust the spray flow rate.

[0030] Please refer to Figure 3. Cylinder 25 includes cylinder body 2510 and cylinder plug 255. Cylinder body 2510 is vertically arranged. Cylinder plug 255 is slidably installed inside cylinder body 2510 and is interference-fitted with the inner wall of cylinder body 2510, dividing cylinder body 2510 into a first chamber 256 and a second chamber 257. Cylinder body 2510 is provided with a first air inlet 258 and a second air inlet 259, which are respectively connected to the first chamber 256 and the second chamber 257. The first air inlet 258 and the second air inlet 259 are connected to an air source device through air pipes, which can use air or nitrogen. The air outlet 251 of cylinder 25 is connected to the first chamber 256. The air outlet 251 is connected to the drive chamber 212 through air inlet pipe 252. An electromagnetic three-way valve 28 is installed on air inlet pipe 252. The electromagnetic three-way valve 28 has a response time of <1s and can quickly switch between air inlet and cut-off states. The exhaust port 254 of cylinder 25 is connected to the second chamber 257. The exhaust port 254 is connected to the nozzle 52 of the flow equalization component 5 through the air supply pipe 521. A check valve 522 is installed on the air supply pipe 521. The direction of the check valve 522 is from the air supply pipe 521 to the nozzle 52 to prevent flue gas or backflow gas from flowing back into the system.

[0031] Please refer to Figure 3. The drive assembly 4 includes a drive wheel 41, a motor 42, a drive rod 43, and a rocker arm 44. The motor 42 is a servo motor and is electrically connected to a PID servo controller. The motor 42 uses a separate power supply for independent start and stop control. The output shaft of the motor 42 is coaxially and fixedly connected to the drive wheel 41. The drive wheel 41 is coaxially and fixedly connected to one end of the drive rod 43. The free end of the drive rod 43 is hinged to the rocker arm 44 via a hinge shaft. The free end of the rocker arm 44 is hinged to the piston rod 253, which limits and guides the rocker arm 44 when it swings. After the motor 42 is started, it drives the drive wheel 41 to rotate. The drive rod 43 moves in a circular motion with the drive wheel 41. Through cooperation with the rocker arm 44, the circular motion is converted into the reciprocating motion of the piston rod 253, thereby compressing the first chamber 256 and the second chamber 257 in the cylinder 25.

[0032] Please refer to Figures 3-5. The flow equalization assembly 5 includes a flow equalization cylinder 51, a nozzle 52, a support plate 53, a support rod 54, a permanent magnet 55, an electromagnet 56, and a compression spring 57. The flow equalization cylinder 51 is vertically installed inside the absorption tower 1 on the side away from the air inlet 11, corresponding to the dead zone of the flue gas. The flow equalization cylinder 51 is made of stainless steel, with openings at both ends. Several flow equalization ports 511 with a diameter of 40-60mm are opened on the side wall near the air inlet 11, so that the flue gas in the mainstream area is evenly distributed. The flow into the equalization cylinder 51 is circulated through the outlet 511. The side wall away from the inlet 11 is fixedly connected to the inner wall of the absorption tower 1. The nozzle 52 is installed directly below the lower opening of the equalization cylinder 51. The outlet end of the nozzle 52 is perpendicular to the lower opening of the equalization cylinder 51. The outside of the nozzle 52 can be equipped with a protective shell to prevent high temperature and high humidity, so as to avoid the high temperature and high humidity environment inside the absorption tower 1. The nozzle 52 is a high-pressure nozzle, and the velocity of the ejected airflow is higher than that of the flue gas flow, which can form a low-pressure zone inside the equalization cylinder 51. The support plate 53 is horizontally fixedly installed on the outside of the absorption tower 1, and the support plate 53 is provided with a slide rail (not shown) arranged along its length. The support rod 54 is slidably connected to the slide rail to guide its horizontal movement. The support rod 54 is made of stainless steel round rod, and its length is not less than the diameter of the absorption tower 1, so that the gas nozzle 52 can cover the entire cross section of the absorption tower 1. The support rod 54 has a hollow structure, so that the gas delivery pipe 521 passes through the support rod 54 and is connected to the gas nozzle 52. A permanent magnet 55 is fixedly installed on the rear end of the support rod 54, and an electromagnetic magnet is installed on the support plate 53. Iron 56 and electromagnet 56 can attract permanent magnet 55 after being energized. The rear end of support rod 54 is connected to compression spring 57. The free end of compression spring 57 is fixedly connected to support plate 53. Compression spring 57 needs to be made of non-magnetic material to avoid affecting the magnetic attraction between permanent magnet 55 and electromagnet 56. The side wall of absorption tower 1 has a through hole (not shown) for support rod 54 to pass through. Flanges or other sealing structures need to be set inside and outside the through hole to prevent flue gas from escaping from there. The first end of support rod 54 passes through the through hole into absorption tower 1 and is fixedly connected to gas nozzle 52.

[0033] When this unit is in operation, pretreatment is first performed by pre-storing ammonia spray medium in storage tank 21. The ammonia water is then heated to 180±10℃ using a steam-heated ammonia preheating device. The PLC control system and associated monitoring equipment are then activated to check the continuity of check valve 27 and check valve 522. The NO-containing caustic soda produced will then be processed... xFlue gas is introduced into the absorption tower 1 through the air inlet 11, and the spray layer 3 is started simultaneously. The water pump continues to replenish ammonia water to the storage tank 21 through the liquid inlet pipe 22. At this time, the electromagnetic three-way valve 28 switches to the open state of the air inlet pipe 252, the motor 42 of the drive component 4 starts, drives the drive wheel 41 to rotate, and drives the piston rod 253 to reciprocate through the cooperation of the drive rod 43 and the rocker arm 44. The cylinder 25 supplies air to the first chamber 256 through the first air inlet 258, pushes the cylinder plug 255 to move, and then drives the piston 24 to slide and squeeze the storage chamber 211, which compensates for the insufficient power of the water pump at the beginning of the start-up, so that the ammonia water is transported to the spray layer 3 through the liquid outlet pipe 23, and finally sprayed out through the atomizing nozzle, avoiding the ineffective consumption of reducing agent caused by premature spraying and the flue gas escape caused by delayed spraying. After the water pump is running normally, the electromagnetic three-way valve 28 switches to the state of cutting off the air inlet pipe 252. The spring 26 drives the piston 24 to reset, and the ammonia water is transported to the spray layer 3 through the liquid inlet pipe 22, the liquid storage tank 21, and the liquid outlet pipe 23. At the same time, the first air inlet 258 and the second air inlet 259 of the cylinder 25 alternately supply air, driving the cylinder piston 255 to continuously reciprocate within the cylinder body 2510. The second chamber 257 delivers high-pressure airflow to the air delivery pipe 521 through the exhaust port 254. The airflow is delivered to the nozzle 52 through the air delivery pipe 521. The nozzle 52 sprays the airflow vertically toward the opening of the flow equalization cylinder 51 at a velocity higher than that of the flue gas. According to Bernoulli's principle, a low-pressure zone is formed inside the flow equalization cylinder 51. The flue gas in the mainstream zone is drawn into the flow equalization cylinder 51 through the flow equalization port 511 and transported upward to fill the dead zone of flue gas far from the air inlet 11, making the flue gas flow field in the absorption tower 1 more uniform, and causing the ammonia water to come into contact with the flue gas and undergo a selective reduction reaction, thus reducing NO. x It is converted into harmless nitrogen and water.

[0034] Example 2: To better realize the above-mentioned ammonia denitrification device, this example provides a denitrification method, including the application of an ammonia denitrification device, including the following steps: Step S10: Ammonia water is pre-stored in the storage tank 21, and the flue gas produced by caustic soda is introduced into the absorption tower 1 through the air inlet 11, and the spray system is started simultaneously. The water pump replenishes ammonia water to the storage tank 21 through the inlet pipe 22; the electromagnetic three-way valve 28 is switched to the open state of the air inlet pipe 252, and the drive component 4 drives the piston rod 253 of the cylinder 25 to reciprocate. Air is supplied to the first chamber 256 through the first air inlet 258, driving the piston 24 to slide and squeeze the liquid storage chamber 211. Ammonia water is transported to the spray layer 3 through the liquid outlet pipe 23 and sprayed out evenly. Step S20: The airflow discharged from the second chamber 257 of the cylinder 25 is transported to the nozzle 52. The nozzle 52 sprays out airflow, which is drawn into the mainstream flue gas through the flow equalization port 511 and transported upward. Step S30: When the absorption tower 1 stops air intake, the support rod 54 slides horizontally along the support plate 53, so that the nozzle 52 moves from the side away from the air inlet 11 to the side of the air inlet 11. The nozzle 52 continues to spray out airflow to push the residual flue gas to continue to flow upward.

[0035] Example 3: The difference between this example and Example 1 is that, because the lower side of the spray pipe 31 in the spray layer 3 is directly exposed to the rising high-temperature NO-containing air in the absorption tower 1... x The flue gas comes into contact with the caustic soda production flue gas (the inlet temperature is typically 170-200℃), while the upper side mainly contacts the atomized low-temperature ammonia droplets and the mixed gas after the reaction. This results in a significantly higher temperature on the lower side of the spray pipe 31 compared to the upper side. This temperature difference easily leads to different degrees of thermal expansion and contraction on the upper and lower sides of the spray pipe 32, which can generate continuous thermal stress during long-term operation, causing the pipe to bend and deform. Therefore, this embodiment further improves upon Embodiment 1 to solve the above problems.

[0036] Please refer to Figures 2 and 6. The spray layer 3 includes multiple sets of spray pipes 31, which are spaced apart along the height of the absorption tower 1. The inlet ends of the multiple sets of spray pipes 31 are connected through the outlet pipe 23, thereby simultaneously supplying ammonia water to the multiple sets of spray pipes 31. The side wall of the absorption tower 1 has blind holes (not shown) for the spray pipes 31 to pass through. The blind holes need to be equipped with sealing flanges and other structures to prevent flue gas from leaking out from there. The inlet end of the spray pipe 31 passes through the blind hole of the absorption tower 1 and is fixedly connected to a rotary joint 32. The other end of the rotary joint 32 is rotatably connected to the outlet pipe 23. The drive wheel 41 is coaxially fixedly connected to a drive gear 45, and the outer shell of the rotary joint 32 is coaxially fixedly connected to a driven gear 46. Both the drive gear 45 and the driven gear 46 are bevel gears, and the drive gear 45 and the driven gear 46 mesh. The motor 42 drives the drive wheel 41 to rotate, which in turn drives the drive gear 45 to rotate, thereby driving the driven gear 46 to rotate, and in turn driving the rotary joint 32 and the spray pipe 31 to rotate. This allows both the upper and lower sides of the spray pipe 31 to rotate and come into contact with the flue gas on the lower side, reducing the problem of uneven temperature caused by the flue gas only contacting the lower side of the spray pipe 31, thus mitigating the temperature difference between the upper and lower parts of the spray pipe 31. It should be noted that since multiple sets of spray pipes 31 are provided, adjacent spray pipes 31 need to be spaced far apart to avoid the upper and lower spray pipes 31 intersecting and causing jamming when the spray pipes 31 rotate. Meanwhile, the remaining spray pipes 31 can be connected to one of the spray pipes 31 through a structure such as a belt and pulley, thereby driving the remaining spray pipes 31 to rotate synchronously.

[0037] Furthermore, to prevent ammonia water from remaining in the spray pipe 31 after spraying, which could lead to scaling and other problems, in this embodiment, the first air inlet 258 of the cylinder 25 is sealed with a sealing plug, that is, the first air inlet 258 of the cylinder 25 is eliminated. When the water pump is running normally, the air inlet pipe 252 is cut off by the electromagnetic three-way valve 28, and the air inlet of the first chamber 256 enters through the electromagnetic three-way valve 28 and enters the first chamber 256 through the air outlet 251. That is, the air inlet and exhaust of the first chamber 256 are both through the air outlet 251. After the water pump starts and the spraying ends, the electromagnetic three-way valve 28 connects to the air inlet pipe 252, and moves via the piston rod 253 to increase the space in the first chamber 256, creating a negative pressure in the first chamber. Gas from the drive chamber 212 is then drawn into the first chamber 256 through the air inlet pipe 252, creating a negative pressure in the liquid storage chamber 211. This allows the ammonia water remaining in the spray pipe 31 to be recovered into the liquid storage tank 21, preventing ammonia water from remaining in the spray pipe 31 and causing structural corrosion. It should be noted that although the liquid storage chamber 211 is also connected to the liquid inlet pipe 22, in this embodiment, the liquid inlet pipe 22 is parallel and perpendicular to the absorption tower 1. Therefore, the negative pressure generated in the liquid storage chamber 211 is insufficient to recover the ammonia water from the liquid inlet pipe 22 into the liquid storage tank 21.

[0038] The above descriptions are merely embodiments of the present invention, and common knowledge regarding specific structures and characteristics is not elaborated upon here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the structure of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. An ammonia denitrification device, comprising an absorption tower (1) and a compensation assembly (2), characterized in that, The compensation component (2) includes: a storage tank (21), which is connected to a spray medium via an inlet pipe (22) and is connected to the spray layer (3) of the absorption tower (1) via an outlet pipe (23); a piston (24), which is slidably disposed in the storage tank (21) to divide the storage tank (21) into a storage chamber (211) and a drive chamber (212); and a cylinder (25), whose outlet (251) is connected to the drive chamber (212) via an inlet pipe (252) to drive the piston (24) to squeeze the storage chamber (211).

2. The ammonia denitrification device according to claim 1, characterized in that: The piston (24) is fixedly connected to a spring (26), and the free end of the spring (26) is fixedly connected to the inner wall of the liquid storage tank (21); a one-way valve (27) is provided on the liquid inlet pipe (22), and the one-way valve (27) is directed from the liquid inlet pipe (22) to the liquid storage tank (21); an electromagnetic three-way valve (28) is provided on the air inlet pipe (252).

3. The ammonia denitrification device according to claim 1, characterized in that: It also includes a drive assembly (4) for reciprocating the piston rod (253) of the cylinder (25). The drive assembly (4) includes a drive wheel (41) and a motor (42). The output shaft of the motor (42) is coaxially fixedly connected to the drive wheel (41). The drive wheel (41) is coaxially fixedly connected to a drive rod (43). A rocker arm (44) is hinged to the free end of the drive rod (43). The free end of the rocker arm (44) is hinged to the piston rod (253).

4. The ammonia denitrification device according to claim 1, characterized in that: It also includes a flow equalization component (5), which includes a flow equalization cylinder (51) and a nozzle (52). The flow equalization cylinder (51) and the nozzle (52) are both located inside the absorption tower (1) and on the side away from the air inlet (11) of the absorption tower (1). The flow equalization cylinder (51) is a flow equalization cylinder (51) with openings at both ends. The flow equalization cylinder (51) is vertically arranged and has several through flow equalization ports (511) on the side near the air inlet (11). The nozzle (52) is located below the flow equalization cylinder (51) and the outlet end of the nozzle (52) is vertically open towards one end of the flow equalization cylinder (51). The nozzle (52) is connected to the exhaust port (254) of the cylinder (25) through the air supply pipe (521).

5. The ammonia denitrification device according to claim 4, characterized in that: The cylinder (25) includes a cylinder body (2510) and a cylinder plug (255). The cylinder plug (255) is slidably disposed in the cylinder body (2510) to divide the cylinder body (2510) into a first chamber (256) and a second chamber (257). The exhaust port (251) is connected to the first chamber (256), and the exhaust port (254) is connected to the second chamber (257). The cylinder body (2510) is provided with a first air inlet (258) and a second air inlet (259). The first air inlet (258) is connected to the first chamber (256), and the second air inlet (259) is connected to the second chamber (257).

6. The ammonia denitrification device according to claim 3, characterized in that: The flow equalization component (5) also includes a support plate (53) and a support rod (54). The support rod (54) is horizontally slidably mounted on the support plate (53). A permanent magnet (55) is mounted on the support rod (54). An electromagnet (56) is mounted on the support plate (53). When the electromagnet (56) is energized, it is used to attract the permanent magnet (55). A compression spring (57) is connected to the support rod (54). The free end of the compression spring (57) is fixedly connected to the support plate (53). One end of the support rod (54) passes through the absorption tower (1) and is fixedly connected to the air nozzle (52).

7. An ammonia denitrification device according to claim 6, characterized in that: The support plate (53) is provided with a slide rail along its length, and the support rod (54) is slidably connected to the slide rail.

8. An ammonia denitrification device according to claim 6, characterized in that: The length of the support rod (54) is not less than the diameter of the absorption tower (1).

9. An ammonia denitrification device according to claim 6, characterized in that: The gas delivery pipe (521) is equipped with a check valve (522), and the direction of the check valve (522) is from the gas delivery pipe (521) to the gas nozzle (52).

10. A method for denitrifying ammonia, comprising using an ammonia denitrification apparatus as described in any one of claims 1-9, characterized in that, The steps include: Step S10: Pre-store ammonia water in the storage tank (21), introduce the flue gas from caustic soda production into the absorption tower (1) through the air inlet (11), and simultaneously start the spray system. The water pump replenishes ammonia water to the storage tank (21) through the inlet pipe (22); the electromagnetic three-way valve (28) switches to the open state of the air inlet pipe (252), and the drive assembly (4) drives the piston rod (253) of the cylinder (25) to reciprocate; supply air to the first chamber (256) through the first air inlet (258), and drive the piston (24) to slide and squeeze the storage chamber (256). 11), ammonia water is transported to the spray layer (3) through the liquid outlet pipe (23) and sprayed out evenly; Step S20: the airflow discharged from the second chamber (257) of the cylinder (25) is transported to the nozzle (52), the nozzle (52) sprays out the airflow, and draws in the flue gas in the mainstream area through the flow equalization port (511) and transports it upward; Step S30: when the absorption tower (1) stops the air intake, the support rod (54) slides horizontally along the support plate (53), so that the nozzle (52) moves from the side away from the air inlet (11) to the side of the air inlet (11), and the nozzle (52) continues to spray out the airflow to push the residual flue gas to continue to flow upward.

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