Special device for effectively treating crystallization blockage of urea-ammonia gas mixture

Abstract

The utility model relates to the technical field of thermal power plant tail gas treatment, in particular to a special device for effectively treating urea-ammonia gas mixed gas crystallization blockage, which comprises an ammonia gas mixer, a steam blowing assembly and a dosing assembly, a dosing pipe is arranged on the side wall of the ammonia gas mixer, one end of the dosing pipe is communicated with an inner cavity of the ammonia gas mixer, and the other end of the dosing pipe is communicated with the steam blowing assembly. The other two ends of the three-way pipe are connected with the steam blowing assembly and the dosing assembly respectively, and the dosing assembly is used for adding a dissolving agent into the inner cavity of the ammonia gas mixer; according to the arranged special device, a chemical feeding assembly pumps a dissolving agent, the dissolving agent flows into a three-way pipe through a chemical conveying pipe, a steam blowing assembly provides high-temperature steam, the dissolving agent is continuously fed into an ammonia gas mixer from the three-way pipe through a chemical feeding pipe by the high-temperature steam, and the dissolving agent rapidly dissolves urea crystals in the high-temperature environment provided by the high-temperature steam; the ammonia gas mixer is dredged, manual cleaning of the ammonia gas mixer is avoided, and the cleaning efficiency of the ammonia gas mixer is conveniently improved.

Description

Technical Field

[0001] This application relates to the field of exhaust gas treatment technology for thermal power plants, specifically to a special device for effectively treating crystallization blockage of urea-ammonia mixed gas. Background Technology

[0002] In thermal power plants, nitrogen oxides are produced during boiler combustion. These nitrogen oxides pollute the environment when released into the atmosphere. To reduce nitrogen oxide emissions in the exhaust gas, the urea denitrification method is often used to treat the exhaust gas. When using urea to reduce nitrogen oxides in the exhaust gas, urea is first hydrolyzed to generate urea product gas. The urea product gas is mainly a mixture of ammonia, water vapor and carbon dioxide. The generated urea product gas is introduced into the reaction system of the furnace, where ammonia reacts with nitrogen oxides to generate nitrogen and water, thereby achieving the goal of reducing nitrogen oxide emissions.

[0003] When urea gas is transported through pipelines, a reverse reaction can easily occur when the temperature is below 125℃, leading to urea crystallization and pipeline blockage. In general, the design of a urea ammonia supply system requires that the urea gas be diluted by heated dilution air before entering the ammonia mixer for thorough mixing, and then entering the reaction system in the furnace. Crystallization can easily form when passing through the flow equalization plate inside the ammonia mixer. Once crystallization occurs, it will affect the flow area and even block the channel, which will directly affect the normal ammonia supply of the unit. Therefore, any abnormality needs to be cleaned up immediately.

[0004] Existing ammonia mixers only have flange inspection holes. If crystallization blockage occurs inside the ammonia mixer, it can only be shut down urgently, and then the flange holes need to be opened for cleaning. This is highly dangerous to personnel, inefficient, and limits the scope of cleaning. Utility Model Content

[0005] In order to improve the cleaning efficiency of ammonia mixers, this application provides a special device for effectively treating crystallization blockage of urea-ammonia mixture.

[0006] The special device for effectively treating crystallization blockage of urea-ammonia mixed gas provided in this application adopts the following technical solution:

[0007] A specialized device for effectively treating crystallization blockage in a urea-ammonia mixture includes: an ammonia mixer, a steam purging assembly, and a dosing assembly. A dosing pipe is provided on the side wall of the ammonia mixer. One end of the dosing pipe is connected to the inner cavity of the ammonia mixer, and the other end is connected to a T-connector. The other two ends of the T-connector are respectively connected to the steam purging assembly and the dosing assembly. The dosing assembly is used to add a solvent to the inner cavity of the ammonia mixer.

[0008] The dosing assembly includes a drug storage tank, a drug delivery pump, a drug delivery pipe, and a first solenoid valve. The drug storage tank contains a solvent. One end of the drug delivery pipe is connected to the three-way pipe, and the other end is connected to the drug storage tank. The drug delivery pump and the first solenoid valve are both mounted on the drug delivery pipe. The drug delivery pump is positioned close to the drug storage tank, and the first solenoid valve is positioned close to the three-way pipe.

[0009] By adopting the above technical solution, when denitrifying the exhaust gas of power plants, urea finished gas is supplied to the boiler furnace through an ammonia mixer to reduce nitrogen oxide emissions. When the urea finished gas undergoes a reverse reaction in the ammonia mixer, producing urea crystals and causing blockage, the dosing component pumps a solvent, the first solenoid valve opens, the dosing pump draws the solvent from the liquid storage tank, and pumps the solvent into the dosing pipe. The solvent flows through the dosing pipe into the tee pipe, and the steam purging component provides high-temperature steam. The high-temperature steam continuously feeds the solvent from the tee pipe into the ammonia mixer through the dosing pipe. The solvent quickly dissolves the urea crystals in the high-temperature environment provided by the high-temperature steam, thus clearing the blockage of the ammonia mixer and avoiding manual cleaning of the ammonia mixer, thereby improving the cleaning efficiency of the ammonia mixer.

[0010] In one specific implementation, the solvent is set as an acetic acid solution.

[0011] By adopting the above technical solution, the solvent is set as an acetic acid solution. The carboxyl group in the acetic acid molecule forms a hydrogen bond with the amino or carbonyl group in the urea molecule, which facilitates the destruction of the crystal lattice structure of urea crystals, so that the urea crystals dissolve in acetic acid.

[0012] In one specific implementation scheme, the steam purging assembly includes a high-temperature steam source, a steam delivery pipe, and a second solenoid valve. One end of the steam delivery pipe is connected to the three-way pipe, and the other end is connected to the high-temperature steam source. The second solenoid valve is fixedly installed on the steam delivery pipe.

[0013] The high-temperature steam source is used to provide high-temperature steam.

[0014] By adopting the above technical solution, when conveying the solvent, the second solenoid valve is opened simultaneously, and the high-temperature steam source supplies high-temperature steam. The high-temperature steam enters the three-way pipe through the steam delivery pipe. At the same time, the high-temperature steam carries the solvent in the three-way pipe into the dosing pipe and flows from the dosing pipe into the ammonia mixer, which facilitates the increase of the solvent flow rate. In addition, the high-temperature steam facilitates the heating of urea crystals, which accelerates the reaction rate of urea crystals with the solvent at high temperature, further improving the cleaning efficiency of the ammonia mixer.

[0015] In one specific implementation, the high-temperature steam source provides high-temperature steam with a temperature higher than 125°C.

[0016] By adopting the above technical solution, the high-temperature steam provided by the high-temperature steam source is higher than 125°C, which heats the ammonia mixer in the ammonia mixer. This helps to avoid the reverse reaction of the urea finished gas, which would cause crystallization, and thus helps to prevent the ammonia mixer from becoming blocked.

[0017] In one specific implementation, the ammonia mixer further includes an inlet flange and an outlet flange, which are located at opposite ends of the length of the ammonia mixer. Both the inlet flange and the outlet flange are connected to the inner cavity of the ammonia mixer and are connected to the ammonia product gas delivery pipeline.

[0018] By adopting the above technical solution, the inlet flange and outlet flange are connected to the ammonia product gas delivery pipeline, which improves the sealing of the ammonia product gas transportation and facilitates the normal delivery of the ammonia product gas to the boiler furnace, thereby reducing nitrogen oxide emissions.

[0019] In one specific implementation, the ammonia mixer further includes multiple flow equalization plates, which are staggered in the inner cavity of the ammonia mixer and fixedly connected to the inner wall of the ammonia mixer, with an ammonia flow channel formed between two adjacent flow equalization plates;

[0020] The flow equalization plate is positioned close to the outlet flange.

[0021] By adopting the above technical solution, the ammonia finished gas is installed through the inlet flange, and the high-temperature steam and solvent enter the inner cavity of the ammonia mixer through the dosing pipe. They are mixed with the ammonia finished gas introduced through the inlet flange. When the mixed gas passes through the flow equalization plate, it generates staggered vortices, which makes the gas uniformly mixed and facilitates the heating and dissolution effect of urea crystals in the ammonia mixer.

[0022] In one specific implementation, the end of the dosing pipe extends into the inner cavity of the ammonia mixer, and the dosing pipe is positioned close to the inlet flange;

[0023] The dosing pipe has a bevel at one end that extends into the ammonia mixer, and the bevel is oriented toward the flow equalization plate.

[0024] By adopting the above technical solution, the bevel of the dosing pipe is set towards the flow equalization plate. After the solvent and high-temperature steam enter the inner cavity of the ammonia mixer, they flow towards the flow equalization plate to dissolve the urea crystals. This helps to avoid the solvent and high-temperature steam flowing back and being discharged from the inlet flange, which would affect the cleaning effect on the ammonia mixer.

[0025] In one specific implementation, a third solenoid valve is also included, which is fixedly mounted on the dosing pipe.

[0026] By adopting the above technical solution, the flow rate of solvent and high-temperature steam in the dosing pipe is controlled by adjusting the opening and closing degree of the third solenoid valve according to the degree of blockage of the ammonia mixer, which helps to avoid the waste of solvent and high-temperature steam.

[0027] In summary, this application includes at least one of the following beneficial technical effects:

[0028] 1. A dedicated device is installed, in which the dosing component pumps the solvent. When the first solenoid valve opens, the dosing pump draws the solvent from the liquid storage tank and pumps it into the dosing pipe. The solvent flows through the dosing pipe into the three-way pipe. The steam purging component provides high-temperature steam, which continuously delivers the solvent from the three-way pipe through the dosing pipe into the ammonia mixer. Under the high-temperature environment provided by the high-temperature steam, the solvent rapidly dissolves the urea crystals, thus clearing the ammonia mixer and eliminating the need for manual cleaning. This improves the cleaning efficiency of the ammonia mixer and also avoids direct contact with ammonia gas during manual cleaning, enhancing the safety of ammonia cleaning.

[0029] 2. The flow equalization plate is installed so that the finished ammonia gas enters from the inlet flange, and the high-temperature steam and solvent enter the inner cavity of the ammonia mixer from the dosing pipe. They mix with the finished ammonia gas introduced from the inlet flange. When the mixed gas passes through the flow equalization plate, it generates staggered vortices, which makes the gas uniformly mixed and facilitates the heating and dissolution effect of urea crystals in the ammonia mixer.

[0030] 3. The bevel of the dosing pipe is set towards the flow equalization plate. After the solvent and high-temperature steam enter the inner cavity of the ammonia mixer, they flow towards the flow equalization plate to dissolve the urea crystals. This helps to prevent the solvent and high-temperature steam from flowing back and being discharged from the inlet flange, which would affect the cleaning effect on the ammonia mixer.

[0031] 4. The third solenoid valve is installed to adjust its opening and closing degree according to the degree of blockage of the ammonia mixer, thereby controlling the flow rate of solvent and high-temperature steam in the dosing pipe and avoiding waste of solvent and high-temperature steam. Attached Figure Description

[0032] The accompanying drawings are provided to further understand this application and form part of the specification. They are used together with the embodiments of this application to explain this application and do not constitute a limitation thereof.

[0033] Figure 1 This is a schematic diagram of the overall structure of a special device for effectively treating crystallization blockage of urea-ammonia mixed gas according to this application.

[0034] Figure 2This is a schematic diagram of an ammonia mixer structure for effectively treating crystallization blockage of urea-ammonia mixed gas according to this application.

[0035] Figure 3 This is a cross-sectional view of an ammonia mixer for effectively treating crystallization blockage of a urea-ammonia mixture according to this application, intended to illustrate the flow equalization plate.

[0036] Figure descriptions: 1. Ammonia mixer; 11. Dosing pipe; 111. Bevel; 112. Third solenoid valve; 12. Inlet flange; 13. Outlet flange; 14. Flow equalization plate; 2. Steam purging assembly; 21. High-temperature steam source; 22. Steam delivery pipe; 23. Second solenoid valve; 3. Dosing assembly; 31. Drug storage tank; 32. Drug delivery pump; 33. Drug delivery pipe; 34. First solenoid valve; 4. T-junction. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0038] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature; in the description of this application, unless otherwise stated, "multiple" means two or more.

[0039] The following is in conjunction with the appendix Figure 1-3 This application will be described in further detail.

[0040] This application discloses a special device for effectively treating the crystallization blockage of urea-ammonia mixed gas.

[0041] Reference Figure 1A specialized device for effectively treating urea-ammonia mixture crystallization blockage includes: an ammonia mixer 1, a three-way pipe 4, a steam purging assembly 2, and a dosing assembly 3. A dosing pipe 11 is fixedly installed on the side wall of the ammonia mixer 1, with one end of the dosing pipe 11 connected to the inner cavity of the ammonia mixer 1 and the other end connected to one end of the three-way pipe 4. The other two ends of the three-way pipe 4 are respectively connected to the steam purging assembly 2 and the dosing assembly 3. The dosing assembly 3 includes a liquid storage tank 31, a delivery pump 32, a delivery pipe 33, and a first solenoid valve 34. The liquid storage tank 31 contains a solvent, which can be an acetic acid solution, a sodium hydroxide solution, or a methanol solution—any solvent capable of dissolving urea crystals is acceptable. In this embodiment, the solvent is... The solution is prepared as acetic acid. Hydrogen bonds are formed between the carboxyl groups in the acetic acid molecules and the amino or carbonyl groups in the urea molecules, which facilitates the disruption of the urea crystal lattice structure, allowing the urea crystals to dissolve in the acetic acid. One end of the delivery tube 33 is connected to the three-way tube 4, and the other end is connected to the drug storage tank 31. The delivery pump 32 and the first solenoid valve 34 are both installed on the delivery tube 33. The delivery pump 32 is located near the drug storage tank 31, and the first solenoid valve 34 is located near the three-way tube 4. The delivery pump 32 draws the solvent from the drug storage tank 31 and pumps the solvent into the delivery tube 33. The solvent flows through the delivery tube 33 into the three-way tube 4, and then into the dosing tube 11. Finally, it enters the ammonia mixer 1 through the dosing tube 11. The solvent dissolves the urea crystals. The steam purging assembly 2 includes a high-temperature steam source 21, a steam delivery pipe 22, and a second solenoid valve 23. One end of the steam delivery pipe 22 is connected to a three-way pipe 4, and the other end is connected to the high-temperature steam source 21. The second solenoid valve 23 is fixedly installed on the steam delivery pipe 22. The high-temperature steam source 21 provides high-temperature steam above 125°C. The high-temperature steam enters the three-way pipe 4 through the steam delivery pipe 22. Simultaneously, the high-temperature steam carries the solvent in the three-way pipe 4 into the dosing pipe 11, and from the dosing pipe 11 flows into the ammonia mixer 1. The high-temperature steam heats the urea crystals, accelerating the reaction rate between the urea crystals and the solvent at high temperature. A third solenoid valve 112 is fixedly installed on the dosing pipe 11 to control the flow rate of the solvent and high-temperature steam in the dosing pipe 11.

[0042] Reference Figure 2 The ammonia mixer 1 also includes an inlet flange 12 and an outlet flange 13. The inlet flange 12 and the outlet flange 13 are located at both ends of the length direction of the ammonia mixer 1. Both the inlet flange 12 and the outlet flange 13 are connected to the inner cavity of the ammonia mixer 1, and the inlet flange 12 and the outlet flange 13 are connected to the ammonia finished gas conveying pipeline.

[0043] Reference Figure 3The ammonia mixer 1 also includes multiple flow equalization plates 14, which are positioned near the outlet flange 13. These plates are staggered within the ammonia mixer 1 and fixedly connected to the inner wall of the ammonia mixer 1, forming an ammonia flow channel between adjacent plates 14. When the mixture of high-temperature steam and ammonia product gas passes through the flow equalization plates 14, a vortex is generated, ensuring uniform mixing of the high-temperature steam, solvent, and ammonia product gas, thus improving the cleaning effect on the ammonia mixer 1. The end of the dosing tube 11 extends into the inner cavity of the ammonia mixer 1, and the dosing tube 11 is located close to the inlet flange 12. The end of the dosing tube 11 that extends into the ammonia mixer 1 has a bevel 111, and the bevel 111 is located towards the flow equalization plate 14. After the solvent and high-temperature steam enter the inner cavity of the ammonia mixer 1, they flow towards the flow equalization plate 14 to dissolve the urea crystals. This helps to prevent the solvent and high-temperature steam from flowing back and being discharged from the inlet flange 12, which would affect the cleaning effect on the ammonia mixer 1.

[0044] The implementation principle of this application for a special device for effectively treating urea-ammonia mixture crystallization blockage is as follows: During the denitrification treatment of power plant exhaust gas, urea finished gas enters from inlet flange 12 and exits from outlet flange 13, and is then introduced into the boiler furnace to reduce nitrogen oxide emissions. When the urea finished gas undergoes a reverse reaction in the ammonia mixer 1, producing urea crystals and causing blockage, the first solenoid valve 34 opens, and the dissolving pump 32 draws solvent from the liquid storage tank 31 and pumps the solvent into the dissolving pipe 33. The solvent flows through the dissolving pipe 33 into the three-way pipe 4. Simultaneously, the second solenoid valve 23 opens, and the high-temperature steam source 21 provides high-temperature steam above 125°C. High-temperature steam enters the three-way pipe 4 through the steam delivery pipe 22. The solvent and high-temperature steam mix in the three-way pipe. The high-temperature steam carries the solvent from the three-way pipe 4 into the dosing pipe 11. The third solenoid valve 112 is opened, and the high-temperature steam and solvent flow from the dosing pipe 11 into the ammonia mixer 1. They mix with the ammonia finished gas introduced through the inlet flange 12. When the mixed gas passes through the ammonia flow channel between two adjacent flow equalization plates 14, it generates staggered vortices, which makes the gas uniformly mixed. The solvent reacts with the urea crystals. The high-temperature steam heats the urea crystals, which accelerates the reaction rate with the solvent at high temperature, causing the urea crystals to dissolve rapidly, thereby cleaning the ammonia mixer 1.

[0045] When cleaning the ammonia mixer 1, the opening and closing degree of the first solenoid valve 34 and the second solenoid valve 23 can be adjusted to regulate the ratio of solvent to high-temperature steam, so as to ensure the cleaning effect of the ammonia mixer 1. At the same time, according to the degree of blockage of the ammonia mixer 1, the opening and closing degree of the third solenoid valve 112 is adjusted to regulate the flow rate of the mixed gas of solvent and high-temperature steam, so as to avoid the waste of solvent and high-temperature steam.

[0046] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit it. This application is not limited to the exact structures described above and illustrated in the accompanying drawings, and it should not be considered that the specific implementation of this application is limited to these descriptions. For those skilled in the art, various changes and modifications made without departing from the concept of this application should be considered to fall within the protection scope of this application.

Claims

1. A special device for effectively treating urea-ammonia gas mixture crystallization blockage, characterized in that, The application relates to an ammonia gas mixer (1), a steam blowing assembly (2) and a dosing assembly (3), a side wall of the ammonia gas mixer (1) is provided with a dosing pipe (11), one end of the dosing pipe (11) is communicated with the inner cavity of the ammonia gas mixer (1), the other end of the dosing pipe (11) is connected with a three-way pipe (4), the other two ends of the three-way pipe (4) are connected with the steam blowing assembly (2) and the dosing assembly (3) respectively, and the dosing assembly (3) is used for adding a dissolving agent into the inner cavity of the ammonia gas mixer (1). The dosing assembly (3) comprises a liquid medicine storage tank (31), a medicine conveying pump (32), a medicine conveying pipe (33) and a first electromagnetic valve (34), the liquid medicine storage tank (31) is provided with the dissolving agent; one end of the medicine conveying pipe (33) is connected with the three-way pipe (4), the other end of the medicine conveying pipe (33) is communicated with the liquid medicine storage tank (31), the medicine conveying pump (32) and the first electromagnetic valve (34) are arranged on the medicine conveying pipe (33), the medicine conveying pump (32) is arranged close to the liquid medicine storage tank (31), and the first electromagnetic valve (34) is arranged close to the three-way pipe (4). The dissolving agent is acetic acid solution.

2. The special device for effectively treating urea-ammonia gas mixture crystallization blockage according to claim 1, characterized in that, The steam blowing assembly (2) comprises a high-temperature steam source (21), a steam conveying pipe (22) and a second electromagnetic valve (23), one end of the steam conveying pipe (22) is connected with the three-way pipe (4), the other end of the steam conveying pipe (22) is communicated with the high-temperature steam source (21), and the second electromagnetic valve (23) is fixedly installed on the steam conveying pipe (22).

3. The device according to claim 1, characterized in that, The high-temperature steam source (21) is used for providing high-temperature steam. The high-temperature steam provided by the high-temperature steam source (21) has a temperature higher than 125 DEG C.

4. The special device for effectively treating urea-ammonia mixed gas crystallization blockage according to claim 3, characterized in that, The ammonia gas mixer (1) further comprises an inlet flange (12) and an outlet flange (13), the inlet flange (12) and the outlet flange (13) are respectively arranged at two ends of the ammonia gas mixer (1) in the length direction, the inlet flange (12) and the outlet flange (13) are communicated with the inner cavity of the ammonia gas mixer (1), and the inlet flange (12) and the outlet flange (13) are connected with an ammonia gas product gas conveying pipeline.

5. The device according to claim 1, characterized in that, The ammonia gas mixer (1) further comprises a plurality of flow uniformizing plates (14), the plurality of flow uniformizing plates (14) are arranged in the inner cavity of the ammonia gas mixer (1) in a staggered mode, the flow uniformizing plates (14) are fixedly connected with the inner wall of the ammonia gas mixer (1), and an ammonia gas flow channel is formed between two adjacent flow uniformizing plates (14).

6. The special device for effectively treating urea-ammonia gas mixture crystallization blockage according to claim 5, characterized in that, The flow uniformizing plates (14) are arranged close to the outlet flange (13). The end of the dosing pipe (11) extends into the inner cavity of the ammonia gas mixer (1), and the dosing pipe (11) is arranged close to the inlet flange (12); 7. The special device for effectively treating urea-ammonia gas mixture crystallization blockage according to claim 6, characterized in that, The end of the dosing pipe (11) extending into the ammonia gas mixer (1) is provided with a bevel (111), and the bevel (111) is arranged towards the flow uniformizing plates (14). A third electromagnetic valve (112) is fixedly arranged on the dosing pipe (11).

8. The special device for effectively treating urea-ammonia gas mixture crystallization blockage according to claim 6, characterized in that, ​

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