A urea ammonia injection pipe cleaning assembly

Abstract

The application discloses a urea ammonia injection pipeline cleaning assembly and relates to the technical field of waste gas separation treatment. The urea ammonia injection pipeline cleaning assembly comprises a denitration reactor for separating and treating waste gas and an ammonia injection component arranged on the denitration reactor and used for conveying urea ammonia injection. The application is provided with a reverse steam blowing structure, a collecting assembly, a rotating assembly and a control assembly. When normal ammonia injection conveying is performed, a forward airflow flows, no additional vortex stirring disturbance exists in the pipeline, the pipe wall thermal boundary layer can be stably maintained, water vapor condensation and new ammonium carbamate crystallization are reduced, the interference of airflow pulsation on crystallization pressure difference early warning monitoring is eliminated, under the blowing condition, steam and block-shaped crystals are separated through transmission, the crystallization fragments are intercepted and stored in the annular collecting cover, the problems of block-shaped crystals rushing into the denitration reactor with airflow to cause catalyst blockage, wear and ammonia escape surge and the like are eliminated from the source, and the dual advantages of pipeline anti-crystallization and reactor equipment protection are considered.

Description

Technical Field

[0001] This invention relates to the field of waste gas separation and treatment equipment technology, specifically a urea ammonia injection pipeline cleaning component. Background Technology

[0002] For the exhaust gas generated by coal-fired units, the urea pyrolysis to ammonia production process is often used. A 32.5% urea aqueous solution is sent into the pyrolysis furnace for high-temperature cracking to generate a high-temperature mixed gas composed of ammonia, carbon dioxide, and water vapor. The mixed gas is sent into the denitrification reactor through the conveying pipe, installation pipe, and ammonia injection head, where it undergoes a selective catalytic reduction reaction with the nitrogen oxides in the flue gas to achieve denitrification and purification of the flue gas.

[0003] The urea pyrolysis mixture contains saturated water vapor. When the valves in the ammonia injection pipeline are not sealed tightly, the pipeline heat tracing is unevenly laid, or the heat tracing temperature does not meet the process requirements, low-temperature areas appear in the pipeline. Ammonia, carbon dioxide and condensate in the mixture undergo a reversible reaction to generate ammonium carbamate crystals. The crystals continuously adhere to the inner walls of the delivery pipe, valves, installation pipe and ammonia injection head, gradually reducing the flow cross-section. In severe cases, this can cause pipeline blockage, valve jamming, and ammonia injection head clogging, leading to a series of operational failures such as unbalanced ammonia injection flow distribution in each branch, decreased denitrification efficiency, and excessive ammonia escape.

[0004] To alleviate the problem of crystallization blockage, existing technologies employ automatic purging control systems with auxiliary steam as the steam source. These systems perform overall purging of pipelines and valves before system startup and after system shutdown, while also conducting periodic preventative purging of standby pipelines. Furthermore, they utilize temperature and differential pressure measuring devices to provide early warning of crystallization. High-temperature steam is introduced to flush away and remove crystals from the pipe walls, thus alleviating pipeline blockage. However, existing steam purging schemes have several inherent and unavoidable drawbacks: First, the purge airflow carries the stripped blocky crystal fragments directly into the denitrification reactor along the pipeline. Large crystals cannot be decomposed by heat in time, which easily blocks the catalyst honeycomb channels and deposits on the surface of the mixing components inside the reactor, blocking the flue gas flow channel, increasing the system flue resistance, and the hard crystal particles continuously scour the catalyst end face, causing catalyst wear, shielding the active sites, and shortening the catalyst service life. Secondly, the existing purging pipeline has a single medium flow direction. The pipeline is shared for normal ammonia transportation and steam purging. It lacks a medium flow direction adaptive diversion and crystallization separation and collection structure. During normal ammonia injection transportation, if the airflow inside the pipeline generates violent stirring and eddy disturbance, it will destroy the stable thermal boundary layer of the pipe wall, promote local condensation of water vapor, and further accelerate the crystallization of ammonium carbamate. At the same time, the airflow pulsation will interfere with the accuracy of the crystallization early warning differential pressure monitoring. To address this, we propose a urea ammonia injection pipeline cleaning component. Summary of the Invention

[0005] The purpose of this invention is to provide a urea-ammonia injection pipeline cleaning component to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a urea ammonia injection pipeline cleaning assembly, comprising a denitrification reactor for separating and treating waste gas and an ammonia injection component disposed on the denitrification reactor for conveying urea ammonia injection, wherein the ammonia injection component comprises multiple sets of mounting pipes disposed on the denitrification reactor, multiple sets of ammonia injection heads connected in communication on the mounting pipes, each set of ammonia injection heads being located inside the denitrification reactor, and a conveying pipe for conveying ammonia injection being disposed outside the denitrification reactor, wherein one end of each set of mounting pipes is connected in communication with the conveying pipe, and further comprising: The air blowing cleaning component is installed on each group of ammonia injection heads and is used to deliver the heated steam toward the interior of the ammonia injection component to blow away the crystals generated inside the pipeline of the ammonia injection component. A collection component, installed on a conveying pipe, is used to collect crystals in the steam during the cleaning process. The collection component is equipped with a separation component for separating the crystals from the steam during the collection process, and a rotating component for assisting the rotation of the separation component. In addition, a control component for controlling the direction of steam flow during steam transportation is installed on the collection component. Through the cooperation of the collection component, separation component, rotation component and control component, the crystals generated after the ammonia injection component is cleaned by blowing air inside are collected.

[0007] Preferably, the air blowing cleaning assembly includes a control valve that is connected to the ammonia injection head. The control valve is connected to a steam pipe for the steam to enter and be transported after heating treatment. One end of each set of steam pipes is located outside the denitrification reactor. By controlling the control valve, the ammonia gas of the ammonia injection component can be transported outward and the steam can be transported inward.

[0008] Preferably, the collection assembly includes a cylinder with flanges fixed at both ends. The cylinder is detachably connected to the end of the conveying pipe via bolts and flanges. An annular collection hood for collecting crystals after processing is provided on the cylinder.

[0009] Preferably, the separation component includes a conical cavity formed inside the cylinder body, the conical cavity being arranged in the same direction as the ammonia gas delivery. A separation cylinder is provided inside the cylinder body, and a conical cylinder is fixed on the separation cylinder. The shape of the conical cylinder matches the conical cavity. Multiple separation grooves for separating steam and crystals are formed on the conical cylinder. An elastic component is provided inside the cylinder body for elastically pushing the conical cylinder. Under the elastic force of the elastic component, the outer side of the conical cylinder communicates with the conical cavity. When ammonia gas is being delivered, the conical cylinder and the conical cavity are kept in contact through the forward airflow. When steam is being delivered, the conical cylinder and the conical cavity are no longer in contact through the reverse airflow, forming an annular separation cavity. The separation cavity is connected to the interior of the annular collection hood.

[0010] Preferably, the cylinder is provided with a sealing ring for sealing the annular collection hood. The two ends of the separation cylinder are divided into a front end and a rear end along the steam conveying direction. A connecting component for auxiliary rotational connection is provided between the sealing ring and the rear end of the separation cylinder. Through the connecting component, when the reverse steam flow pushes the conical cylinder in the opposite direction, it drives the sealing ring to move synchronously, thereby releasing the sealing ring from the annular collection hood.

[0011] Preferably, the rotating assembly includes a fixed cylinder fixed to the front end of the conical cylinder, and multiple sets of inclined blades are fixed to the outer side of the fixed cylinder. During steam transportation, the fixed cylinder and the conical cylinder rotate due to the interaction between the steam and each set of blades.

[0012] Preferably, the control component includes a mounting plate centrally located inside the cylinder. The mounting plate is connected and fixed to the inner wall of the cylinder via multiple sets of mounting brackets. A plug for sealing against the inner side of the conical cylinder is centrally fixed at one end of the mounting plate facing the conical cylinder. During ammonia transportation, the plug does not seal the conical cylinder. However, during steam transportation, as the conical cylinder moves, the plug abuts against the inner side of the conical cylinder, controlling the steam flow to the separation chamber.

[0013] Preferably, multiple sets of the elastic components are arranged in a ring array inside the cylinder. Each elastic component includes a fixing plate fixed to the inner side of the sealing ring, a sliding rod fixed on the fixing plate, a sleeve slidably connected to the sliding rod, one end of the sleeve being fixed to the mounting plate, and a spring sleeved on the outer side of the sleeve. The two ends of the spring are respectively abutted against the mounting plate and the fixing plate.

[0014] Preferably, the connecting assembly includes an annular groove formed at the end of the sealing ring, a connecting ring rotatably connected inside the annular groove, the connecting ring being fixed to the end of the separating cylinder, and the sealing ring, annular groove, connecting ring and separating cylinder being concentrically arranged.

[0015] Preferably, the annular collecting hood is provided with a discharge assembly for unloading the collected crystallized material. The discharge assembly includes a conical discharge cylinder that is connected to the bottom of the annular collecting hood, and the conical discharge cylinder is threadedly connected with a threaded plug.

[0016] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention integrates a cylindrical gas-solid separation and collection component on the conveying pipe. When the steam is purged in reverse, the plug seals the central channel of the conical cylinder, forcing the steam carrying the crystals to flow through the annular separation chamber. The blocky ammonium carbamate crystals are intercepted inside the annular collection hood by the separation tank and the centrifugal action of the vortex blades. This prevents hard crystal fragments from being carried into the denitrification reactor by the airflow from the source. It can prevent the crystal rack from clogging the catalyst honeycomb pores and scouring and wearing the catalyst carrier. At the same time, it can prevent the concentrated decomposition of crystals from releasing a large amount of ammonia gas and causing an instantaneous surge in ammonia escape, thereby reducing the risk of ammonium bisulfate blockage and corrosion in the downstream air preheater. 2. When ammonia is being transported in the forward direction, this invention pushes the conical cylinder to press tightly against the conical cavity, and the annular separation cavity is closed. The internal flow channel of the pipeline is smooth without additional stirring or eddy current disturbance, which can stably maintain the thermal boundary layer of the pipe wall, avoid local condensation of saturated water vapor in the mixed gas, significantly reduce the precipitation of secondary crystallization of ammonium carbamate, and at the same time eliminate the pressure pulsation of the pipeline airflow, ensure the stability of the monitoring data of the differential pressure crystallization early warning device, and reduce the probability of false alarms and missed alarms. 3. This invention relies on the forward flow of ammonia and the reverse flow of steam in conjunction with the elastic component spring to achieve automatic axial displacement of the conical cylinder and the sealing ring. It can complete the adaptive switching of the two working conditions without the need for electric or pneumatic actuators. When ammonia is injected, the collection channel is closed and the central ammonia delivery channel is opened. When purging, the separation collection chamber is opened and the central DC path is closed. The mechanical linkage response is rapid, reducing electrical control components and lowering the equipment failure rate and modification cost. 4. During the purging process of this invention, the reverse steam impacts the tilted vanes, driving the conical cylinder and the separation cylinder to rotate as a whole. Under the action of centrifugal force, the crystals adhering to the outer wall of the conical cylinder and the separation groove can be quickly peeled off and fall to the annular collection hood, preventing the accumulation of crystals from clogging the separation groove and causing separation failure. The sealing ring and the separation cylinder adopt an annular groove and a rotating fit structure with the connecting ring. It only slides axially and does not rotate with the cylinder body, taking into account both sliding sealing and rotational separation functions. The separation efficiency is stable during long-term operation. 5. This invention features an annular collection hood with a conical discharge cylinder and a threaded plug. The crystals shed during purging are temporarily stored in the collection hood, eliminating the need for mid-process shutdown for cleaning. During unit maintenance and low-load windows, only the bottom threaded plug needs to be unscrewed, and the accumulated crystals can be discharged by gravity. This eliminates the need to disassemble the entire ammonia injection pipeline for manual unclogging, significantly reducing downtime for maintenance, extending the continuous operation cycle of the denitrification system, and reducing manual maintenance costs. Attached Figure Description

[0017] Figure 1This is a schematic diagram of the overall external structure of the present invention; Figure 2 This is a schematic diagram of the internal structure of the denitrification reactor of the present invention; Figure 3 This is a schematic diagram of the air-blowing cleaning component structure of the present invention; Figure 4 This is a schematic diagram showing the state of the collection component of the present invention after it has been installed on the delivery pipe; Figure 5 This is a schematic diagram of the internal structure of the collection component of the present invention; Figure 6 This is a schematic diagram of the separation component, sealing ring, and rotating component of the present invention; Figure 7 This is a schematic diagram of the control component, elastic component, and connecting component of the present invention; Figure 8 This is a schematic diagram of the state of the collection component of the present invention during urea ammonia injection and delivery; Figure 9 This is a schematic diagram of the state of the collection component of the present invention during purging, cleaning and conveying.

[0018] In the diagram: 101, Denitrification reactor; 102, Installation pipe; 103, Ammonia injection head; 104, Conveying pipe; 201, Control valve; 202, Steam pipe; 301, Cylinder; 302, Annular collection hood; 303, Flange; 401, Conical cavity; 402, Separation cylinder; 403, Conical cylinder; 404, Separation trough; 5, Sealing ring; 601, Fixed cylinder; 602, Rotary blade; 701, Mounting plate; 702, Mounting bracket; 703, Plug; 801, Fixed plate; 802, Slide rod; 803, Sleeve; 804, Spring; 901, Annular groove; 902, Connecting ring; 1001, Conical discharge cylinder; 1002, Threaded plug. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Example 1

[0021] Please see Figures 1-9The diagram shows a urea ammonia injection pipeline cleaning assembly, which includes a denitrification reactor 101 for separating and treating waste gas and an ammonia injection component disposed on the denitrification reactor 101 for conveying urea ammonia injection. The ammonia injection component includes multiple sets of mounting pipes 102 disposed on the denitrification reactor 101, and multiple sets of ammonia injection heads 103 connected in communication on the mounting pipes 102. Each set of ammonia injection heads 103 is located inside the denitrification reactor 101, and a conveying pipe 104 for conveying ammonia injection is disposed on the outside of the denitrification reactor 101. One end of each set of mounting pipes 102 is connected in communication with the conveying pipe 104. It should be noted here that: when the denitrification process is started, the control valve 201 at the ammonia injection head 103 closes the steam pipe 202, cutting off the external high-temperature steam supply. The ammonia gas mixture generated by urea pyrolysis is transported in the forward direction along the conveying pipe 104, flowing to the cylinder 301 and the installation pipe 102, and finally being injected into the denitrification reactor 101 from the ammonia injection head 103. The waste gas inside the denitrification reactor 101 is separated and treated, and a catalytic reduction reaction is carried out with the nitrogen oxides in the flue gas to complete the denitrification operation. Furthermore, the entire denitrification process, principle, and control method are known technologies in this application, and their working principles, steps, and specific structures will not be elaborated upon here.

[0022] Also includes: The air blowing cleaning component is installed on each group of ammonia injection heads 103 and is used to transport the heated steam toward the interior of the ammonia injection component to blow away the crystallization generated inside the pipeline of the ammonia injection component. A collection component is installed on the conveying pipe 104 for collecting crystals in the steam during the cleaning process. The collection component is equipped with a separation component for separating the crystals from the steam during the collection process, and a rotating component is installed on the separation component to assist the rotation of the separation component. In addition, a control component for controlling the direction of steam flow during steam transportation is installed on the collection component. Through the cooperation of the collection component, separation component, rotation component and control component, the crystals generated after the ammonia injection component is cleaned by blowing air inside are collected. It should be noted that by setting up a reverse steam purging structure in conjunction with a collection component, a rotating component, and a control component, the forward airflow is maintained during normal ammonia injection and transportation. There is no additional eddy current stirring disturbance inside the pipeline, which can stably maintain the thermal boundary layer on the pipe wall, reduce water vapor condensation and new crystallization of ammonium carbamate, and eliminate the interference of airflow pulsation on the crystallization pressure difference early warning monitoring. During the purging operation, the steam and block crystals are separated through transmission, and the crystal fragments are intercepted and stored in the annular collection hood 302. This prevents block crystals from being carried into the denitrification reactor 101 by the airflow, which could cause problems such as catalyst blockage, wear, and a sudden increase in ammonia escape. This achieves the dual advantages of pipeline anti-crystallization and reactor equipment protection.

[0023] Preferably, the air blowing cleaning assembly includes a control valve 201 connected to the ammonia injection head 103. A steam pipe 202 for entering and conveying steam after heating treatment is connected to the control valve 201. One end of each steam pipe 202 is located outside the denitrification reactor 101. By controlling the control valve 201, the ammonia gas of the ammonia injection component can be conveyed to the outside and the steam can be conveyed to the inside. It should be noted here that: when the ammonia supply at the front end is cut off and the control valve 201 at the ammonia injection head 103 is opened, the high-temperature heated steam is introduced into the ammonia injection component in the reverse direction through the steam pipe 202 and the ammonia injection head 103. The steam flow direction is completely opposite to the ammonia delivery direction. The high-temperature reverse steam flows from the ammonia injection head 103 and the installation pipe 102 to flush the inner wall of the pipeline in the reverse direction, peeling off and breaking the ammonium carbamate crystals attached to the pipe wall, valve cavity, and inner cavity of the ammonia injection head 103, forming crystal fragments mixed in the steam flow, and flowing back towards the delivery pipe 104 and the cylinder 301. Furthermore, the working principles, steps, and specific structures of the steam delivery control, temperature control, and crystal cleaning technology within the technical field of this application will not be elaborated upon here.

[0024] Preferably, the collection assembly includes a cylinder 301, with flanges 303 fixed at both ends. The cylinder 301 is detachably connected to the end of the conveying pipe 104 via bolts through the flanges 303. An annular collection hood 302 for collecting crystals after processing is provided on the cylinder 301. The separation assembly includes a conical cavity 401 opened inside the cylinder 301, which is arranged in the same direction as the ammonia gas conveying direction. A separation cylinder 402 is provided inside the cylinder 301, and a conical cylinder 403 is fixed on the separation cylinder 402. The shape of the conical cylinder 403 matches the conical cavity 401. Multiple sets of separation tanks 404 for separating steam and crystallization are provided on the cylinder 301. The inside of the cylinder 301 is provided with an elastic component for elastically pushing the conical cylinder 403. Under the elastic force of the elastic component, the outer side of the conical cylinder 403 is connected to the conical cavity 401. When ammonia gas is transported, the conical cylinder 403 and the conical cavity 401 are kept in a state of contact through the forward airflow. When steam is transported, the conical cylinder 403 and the conical cavity 401 are no longer in contact through the reverse airflow and form an annular separation chamber. The separation chamber is connected to the inside of the annular collection hood 302. It should be noted that: the reverse steam carrying the crystal fragments enters the cylinder 301 and, through transmission, forces all the steam into the annular separation chamber. The steam and the crystals mixed in the steam that enter the annular separation chamber are separated by multiple sets of separation tanks 404. The steam can pass through the separation tanks 404 into the inner side of the cylinder 301 and continue to be conveyed backward. The generated crystals are filtered and separated by the separation tanks 404 and, driven by the steam, enter the annular collection hood 302 for collection. This completes the separation and collection of crystals generated during the cleaning process. In addition, the steam blocking control component, in conjunction with the control component, plays a role in steam flow guidance, ensuring that the conveyed steam can be effectively separated and processed, guaranteeing the separation effect of crystals present in the steam.

[0025] Preferably, the cylinder 301 is provided with a sealing ring 5 for sealing the annular collection hood 302. The two ends of the separation cylinder 402 are divided into a front end and a rear end along the steam conveying direction. A connecting component for auxiliary rotational connection is provided between the sealing ring 5 and the rear end of the separation cylinder 402. Through the connecting component, when the reverse steam flow pushes the conical cylinder 403 in the opposite direction, the sealing ring 5 is driven to move synchronously, thereby releasing the sealing ring 5 from the state of sealing the annular collection hood 302. It should be noted here that by pressing the opening of the annular collection hood 302 on the side wall of the cylinder 301 with the sealing ring 5, the annular collection hood 302 is completely sealed to prevent ammonia and flue gas from backflowing into the collection area.

[0026] Preferably, the rotating assembly includes a fixed cylinder 601 fixed to the front end of the conical cylinder 403, and multiple sets of inclined blades 602 are fixed to the outside of the fixed cylinder 601. During steam transportation, the fixed cylinder 601 and the conical cylinder 403 rotate due to the interaction between the steam and each set of blades 602. It should be noted that when the reverse steam flows through the inclined vane 602 at the front end of the conical cylinder 403, the airflow impacts the vane 602 to generate a circumferential driving force, which drives the fixed cylinder 601, the conical cylinder 403, and the separation cylinder 402 to rotate continuously. Through the rotation of the conical cylinder 403, combined with centrifugal force, the crystals separated on the outer surface of the conical cylinder 403 can be effectively detached and enter the interior of the annular collection hood 302, thus avoiding the accumulation of crystals on the outer side of the conical cylinder 403 from affecting the subsequent continuous separation process.

[0027] Preferably, the control component includes a mounting plate 701 centrally disposed inside the cylinder 301. The mounting plate 701 is connected and fixed to the inner wall of the cylinder 301 by multiple sets of mounting brackets 702. A plug 703 for abutting and sealing against the inner side of the conical cylinder 403 is centrally fixed at one end of the mounting plate 701 facing the conical cylinder 403. When ammonia is transported, the plug 703 does not seal the conical cylinder 403. However, when steam is transported, the plug 703 abuts and seals against the inner side of the conical cylinder 403 as the conical cylinder 403 moves, thereby controlling the steam flow to the separation chamber. It should be noted here that: the reverse steam carrying the crystal fragments enters the interior of the cylinder 301, and the thrust of the reverse steam acts on the front end of the conical cylinder 403, pushing the conical cylinder 403 and the separation cylinder 402 as a whole to move along the steam conveying direction. After the conical cylinder 403 moves, its outer wall and the conical cavity 401... When the two parts are disengaged, an annular separation chamber is formed between them. At the same time, the rear end of the separation cylinder 402 is connected by the connecting component, which drives the sealing ring 5 to slide synchronously. The sealing ring 5 releases the seal on the opening of the annular collection cover 302. At this time, the annular separation chamber is connected to the inner cavity of the annular collection cover 302. In addition, after the conical cylinder 403 moves, since the positions of the mounting plate 701 and the plug 703 inside the cylinder 301 are relatively fixed, the plug 703 is inserted into the inner channel of the conical cylinder 403 as the conical cylinder 403 moves, completely blocking the inner passage of the conical cylinder 403. The reverse steam cannot pass directly through the inner channel of the conical cylinder 403 and is forced to enter the interior of the annular separation chamber. The steam and the crystals mixed in the steam that enter the annular separation chamber are separated by multiple sets of separation tanks 404.

[0028] Preferably, multiple sets of elastic components are arranged in a ring array inside the cylinder 301. The elastic components include a fixing plate 801 fixed to the inner side of the sealing ring 5, a sliding rod 802 fixed on the fixing plate 801, a sleeve 803 slidably connected to the sliding rod 802, one end of the sleeve 803 being fixed to the mounting plate 701, and a spring 804 being sleeved on the outer side of the sleeve 803. The two ends of the spring 804 are respectively abutted against the mounting plate 701 and the fixing plate 801. It should be noted here that: the sleeve 803 and the slide rod 802 facilitate the telescopic connection between the auxiliary fixing plate 801 and the mounting plate 701. The elastic force of the spring 804, in conjunction with the connection of the fixing plate 801, the sealing ring 5, the connecting assembly and the separating cylinder 402, makes the conical cylinder 403 abut against the inner wall of the conical cavity 401.

[0029] Preferably, the connecting component includes an annular groove 901 formed at the end of the sealing ring 5, and a connecting ring 902 is rotatably connected inside the annular groove 901. The connecting ring 902 is fixed to the end of the separating cylinder 402. The sealing ring 5, the annular groove 901, the connecting ring 902 and the separating cylinder 402 are concentrically arranged. It should be noted that the annular groove 901 and the connecting ring 902 facilitate the rotatable connection between the auxiliary sealing ring 5 and the separating cylinder 402. In addition, during the movement of the separating cylinder 402, the connection between the annular groove 901 and the connecting ring 902 can drive the sealing ring 5 to move synchronously.

[0030] Preferably, the annular collection hood 302 is provided with a discharge assembly for unloading the collected crystallized material. The discharge assembly includes a conical discharge cylinder 1001 that is connected to the bottom of the annular collection hood 302. A threaded plug 1002 is threadedly connected to the conical discharge cylinder 1001. It should be noted that the crystals collected after separation accumulate inside the annular collection hood 302. When it is necessary to unload the crystals, the threaded plug 1002 is removed from the conical discharge cylinder 1001, so that the crystals inside the annular collection hood 302 are discharged outward through the conical discharge cylinder 1001.

[0031] This solution includes a urea-ammonia injection pipeline cleaning component. The cleaning component operates in two main processes: normal ammonia injection denitrification mode and reverse steam purging crystallization cleaning mode. The specific working steps are as follows: I. Normal Ammonia Injection and Transportation Procedures for Denitrification The denitrification process is initiated by controlling valve 201 at ammonia injection head 103 to close steam pipe 202, cutting off the external high-temperature steam supply. The ammonia mixture generated by urea pyrolysis is transported forward along conveying pipe 104, flowing towards cylinder 301 and installation pipe 102, and finally injected into the denitrification reactor 101 from ammonia injection head 103. This process separates and treats the waste gas inside the denitrification reactor 101, causing a catalytic reduction reaction with nitrogen oxides in the flue gas, thus completing the denitrification operation. During the ammonia transport on cylinder 301, the forward ammonia flow impacts conical cylinder 403, and the elastic force of spring 804 on the elastic component acts on sealing ring 5, separation cylinder 402, and conical cylinder 403, pushing them to move along the ammonia transport direction. This ensures that the outer wall of conical cylinder 403 tightly adheres to the conical cavity 401 inside cylinder 301. At this time, there is no annular separation cavity between conical cylinder 403 and conical cavity 401 (see...). Figure 8 (in the state of the cylinder 301), the annular collection hood 302 opening is pressed by the sealing ring 5 to completely seal the annular collection hood 302, so as to prevent ammonia and flue gas from backflowing into the collection area. During the ammonia gas transportation process, the plug 703 on the mounting plate 701 separates from the inner wall of the conical cylinder 403, allowing the ammonia gas mixture to pass smoothly through the internal channels of the separator 402 and the conical cylinder 403, and continuously supplying it to the ammonia spray head 103. During the ammonia gas mixture transportation process, the ammonia gas mixture does not exert fluid force on the swivel blade 602. At this time, the conical cylinder 403 does not rotate, making the internal flow field of the ammonia gas mixture transportation pipeline smooth without additional eddy current disturbance, reducing the formation of new crystals. II. Pre-treatment steps for steam purging and crystallization cleaning Cut off the ammonia supply at the front end, open the control valve 201 at the ammonia injection head 103, and the high-temperature heated steam is reversed through the steam pipe 202 and the ammonia injection head 103 into the ammonia injection component. The steam flow direction is completely opposite to the ammonia delivery direction. The high-temperature reverse steam washes the inner wall of the pipeline from the ammonia injection head 103 and the installation pipe 102, peeling off and breaking the ammonium carbamate crystals attached to the pipe wall, valve cavity, and inner cavity of the ammonia injection head 103. The crystal fragments are mixed in the steam flow and flow back towards the delivery pipe 104 and the cylinder 301. Reverse steam carrying crystal fragments enters the interior of cylinder 301. The thrust of the reverse steam acts on the front end of conical cylinder 403, pushing conical cylinder 403 and separation cylinder 402 as a whole to move along the steam conveying direction. After the conical cylinder 403 moves, its outer wall disengages from the conical cavity 401, forming an annular separation cavity between them. At the same time, the rear end of separation cylinder 402, through the connecting component, drives the sealing ring 5 to slide synchronously. The sealing ring 5 releases the seal on the opening of the annular collection hood 302. At this time, the annular separation cavity is connected to the inner cavity of the annular collection hood 302. In addition, after the conical cylinder 403 moves, due to the position of the mounting plate 701 and the plug 703 inside cylinder 301... The plug 703 is relatively fixed, so that it is inserted into the inner channel of the conical cylinder 403 as the conical cylinder 403 moves, completely blocking the inner channel of the conical cylinder 403. Reverse steam cannot pass directly through the inner channel of the conical cylinder 403 and is forced to enter the annular separation chamber. The steam and crystals mixed in the steam entering the annular separation chamber are separated by multiple sets of separation tanks 404. The steam can pass through the separation tanks 404 into the inner side of the cylinder 301 and continue to be conveyed backwards. The generated crystals are filtered and separated by the separation tanks 404 and, driven by the steam, enter the annular collection hood 302 for collection (see...). Figure 9 (in the state of the process), the separation and collection of crystals generated during the cleaning process is completed. In addition, the control component, together with the control component, controls the steam blockage and guides the steam flow, so that the delivered steam can be effectively separated and processed, ensuring the separation effect of crystals in the steam. When the reverse steam flows through the inclined vane 602 at the front end of the conical cylinder 403, the airflow impacts the vane 602 to generate a circumferential driving force, which drives the fixed cylinder 601, the conical cylinder 403, and the separation cylinder 402 to rotate continuously. Through the rotation of the conical cylinder 403, combined with centrifugal force, the crystals separated on the outer surface of the conical cylinder 403 can be effectively detached and enter the interior of the annular collection hood 302, avoiding the accumulation of crystals on the outer side of the conical cylinder 403 from affecting the subsequent continuous separation process.

[0032] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0033] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A urea-ammonia spraying pipeline cleaning assembly, comprising: A denitrification reactor (101) for separating and treating waste gas and an ammonia injection component installed on the denitrification reactor (101) for conveying ammonia to urea. The ammonia injection component includes multiple sets of mounting pipes (102) installed on the denitrification reactor (101). Multiple sets of ammonia injection heads (103) are connected in communication on the mounting pipes (102). Each set of ammonia injection heads (103) is located inside the denitrification reactor (101). A conveying pipe (104) for conveying ammonia is installed on the outside of the denitrification reactor (101). One end of each set of mounting pipes (102) is connected in communication with the conveying pipe (104). Its characteristic is that it further includes: The air blowing cleaning component is installed on each group of ammonia spray heads (103) and is used to transport the heated steam toward the interior of the ammonia spraying component to blow away the crystals generated inside the pipeline of the ammonia spraying component. A collection component is provided on the conveying pipe (104) for collecting crystals in the steam during the cleaning process. The collection component is provided with a separation component for separating the crystals from the steam during the collection process. The separation component is provided with a rotating component to assist the rotation of the separation component. In addition, a control component for controlling the direction of steam flow during steam transportation is installed on the collection component. Through the cooperation of the collection component, separation component, rotation component and control component, the crystals generated after the ammonia injection component is cleaned by blowing air inside are collected.

2. The urea-ammonia injection pipeline cleaning component according to claim 1, characterized in that: The air blowing cleaning assembly includes a control valve (201) connected to the ammonia spray head (103). The control valve (201) is connected to a steam pipe (202) for the steam to enter and be transported after heating treatment. One end of each steam pipe (202) is located outside the denitrification reactor (101). By controlling the control valve (201), the ammonia gas of the ammonia spraying component can be transported outward and the steam can be transported inward.

3. A urea-ammonia spraying pipeline cleaning component according to claim 2, characterized in that: The collection assembly includes a cylinder (301), with flanges (303) fixed at both ends of the cylinder (301). The cylinder (301) is detachably connected to the end of the conveying pipe (104) via bolts and flanges (303). An annular collection cover (302) for collecting crystals after processing is provided on the cylinder (301).

4. A urea-ammonia spraying pipeline cleaning component according to claim 3, characterized in that: The separation assembly includes a conical cavity (401) formed inside the cylinder (301), the conical cavity (401) being arranged in the same direction as the ammonia gas delivery. A separation cylinder (402) is disposed inside the cylinder (301), and a conical cylinder (403) is fixed on the separation cylinder (402). The shape of the conical cylinder (403) matches that of the conical cavity (401). Multiple sets of separation tanks (404) for separating vapor and crystallization are formed on the conical cylinder (403). The cylinder (301) also has internal structures for... The elastic component pushes the conical cylinder (403) with elastic force, and under the elastic force of the elastic component, the outer side of the conical cylinder (403) is connected to the conical cavity (401). When ammonia gas is transported, the conical cylinder (403) and the conical cavity (401) are kept in a state of contact through the forward airflow. When steam is transported, the conical cylinder (403) and the conical cavity (401) are no longer in contact through the reverse airflow and are connected to the inner side of the conical cylinder (403), forming an annular separation cavity. The separation cavity is connected to the inner side of the annular collection hood (302).

5. A urea-ammonia injection pipeline cleaning assembly according to claim 1, characterized in that: The cylinder (301) is provided with a sealing ring (5) for sealing the annular collection hood (302). The two ends of the separation cylinder (402) are divided into a front end and a rear end along the steam conveying direction. A connecting component for auxiliary rotation connection is provided between the sealing ring (5) and the rear end of the separation cylinder (402). Through the connecting component, when the reverse steam flow pushes the conical cylinder (403) in the opposite direction, the sealing ring (5) moves synchronously, releasing the sealing ring (5) from the state of sealing the annular collection hood (302).

6. A urea-ammonia spraying pipeline cleaning assembly according to claim 5, characterized in that: The rotating assembly includes a fixed cylinder (601) fixed to the front end of the conical cylinder (403). Multiple sets of inclined blades (602) are fixed on the outside of the fixed cylinder (601). During steam transportation, the fixed cylinder (601) and the conical cylinder (403) rotate due to the interaction between the steam and each set of blades (602).

7. A urea-ammonia injection pipeline cleaning assembly according to claim 5, characterized in that: The control component includes a mounting plate (701) centrally located inside the cylinder (301). The mounting plate (701) is connected and fixed to the inner wall of the cylinder (301) by multiple sets of mounting brackets (702). A plug (703) for sealing against the inner side of the conical cylinder (403) is centrally fixed at one end of the mounting plate (701) facing the conical cylinder (403). When ammonia is transported, the plug (703) does not seal the conical cylinder (403). However, when steam is transported, the plug (703) abuts against the inner side of the conical cylinder (403) to seal it as the conical cylinder (403) moves, thus controlling the steam flow to the separation chamber.

8. A urea-ammonia injection pipeline cleaning assembly according to claim 7, characterized in that: The elastic components are arranged in a ring array inside the cylinder (301) in multiple sets. The elastic components include a fixing plate (801) fixed to the inner side of the sealing ring (5). A sliding rod (802) is fixed on the fixing plate (801). A sleeve (803) is slidably connected to the sliding rod (802). One end of the sleeve (803) is fixed to the mounting plate (701). A spring (804) is sleeved on the outside of the sleeve (803). The two ends of the spring (804) are respectively abutted against the mounting plate (701) and the fixing plate (801).

9. A urea-ammonia injection pipeline cleaning assembly according to claim 5, characterized in that: The connecting assembly includes an annular groove (901) opened at the end of the sealing ring (5), and a connecting ring (902) is rotatably connected inside the annular groove (901). The connecting ring (902) is fixed to the end of the separating cylinder (402). The sealing ring (5), the annular groove (901), the connecting ring (902) and the separating cylinder (402) are concentrically arranged.

10. A urea-ammonia injection pipeline cleaning assembly according to claim 3, characterized in that: The annular collection hood (302) is provided with a discharge assembly for unloading the collected crystallized material. The discharge assembly includes a conical discharge cylinder (1001) installed at the bottom of the annular collection hood (302). A threaded plug (1002) is threadedly connected to the conical discharge cylinder (1001).

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