Denitration and demisting device based on urea hydrolysis
By designing the spray tube bundle in urea hydrolysis and denitrification technology, and diluting and condensing mist with cooling dilution water, the problem of mist spreading in urea hydrolysis and denitrification technology is solved, achieving a safer and more environmentally friendly operating environment.
Patent Information
- Application Number
- CN202421827660.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-31
- Publication Date
- 2025-05-06
- Estimated Expiration
- 2034-07-31
AI Technical Summary
The hydrophobic and incompletely reacted urea solution produced by urea hydrolysis technology during hydrolysis will form mist when discharged, causing the fog to spread in the workshop, affecting operation and environmental protection.
A denitrification and defogging device based on urea hydrolysis is designed. By setting a spray tube bundle in the hydrolysis device and dissolution tank, diluting and condensing with cooling diluted water, the temperature and concentration of the mist are reduced, thereby preventing the mist from spreading.
It effectively reduces the temperature and concentration of the fog, prevents it from spreading in the workshop, improves the working environment, improves the safety and environmental protection of the operation, and reduces the health impact on the operators.
Smart Images
Figure CN222829392U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of industrial flue gas SCR urea hydrolysis denitrification, in particular to a denitrification and demisting device based on urea hydrolysis. Background Art
[0002] Urea hydrolysis denitrification technology is an environmentally friendly denitrification technology that uses urea as a reducing agent and is safer than liquid ammonia. Therefore, the state requires that liquid ammonia be replaced by urea hydrolysis to produce ammonia. At present, most of the domestic thermal power plants with a capacity of 300MW and above have replaced liquid ammonia with urea hydrolysis to produce ammonia.
[0003] The reaction principle of urea hydrolysis and denitrification is as follows: First, granular urea is dissolved into a urea solution with a mass concentration of 50% in a urea dissolving tank, and then stored in a storage tank and pumped to the shell side of the urea hydrolysis reactor by a delivery pump. Next, 200-250 saturated steam is used as a hydrolysis heat source, and the solution is indirectly heated to about 150 through the heat exchange tube bundle in the hydrolyzer tube side for hydrolysis reaction, producing ammonia with a concentration of about 37%. Finally, the generated ammonia is transported to the furnace area SCR reactor for denitrification reaction.
[0004] However, since a large amount of hydrophobic water is generated during the hydrolysis process, and the temperature of the hydrophobic water is close to 90-100, when it is pumped into the wastewater pool through the drain valve pipeline, a large amount of mist will spread in the workshop. In addition, when the hydrolyzer is discharged accidentally or shut down for maintenance, the unreacted urea solution in the hydrolyzer is discharged to the dissolution tank through the sewage valve pipeline, which will also cause mist to spread. These situations will affect the workshop operation and maintenance personnel, limiting the application of urea hydrolysis and denitrification. Utility Model Content
[0005] In view of the above-mentioned deficiencies in the prior art, the purpose of the present application is to provide a denitrification and demisting device based on urea hydrolysis, which includes a hydrolyzer, wherein a steam valve pipeline is provided on one side of one end of the heat exchange tube of the hydrolyzer passing through the hydrolyzer, and the other side is connected to a drain tank through a drain valve pipeline, and the drain tank is connected to a cooling dilution water pipeline through a first dilution water valve pipeline.
[0006] Preferably, the bottom of the hydrolyzer is connected to the dissolution tank via a sewage valve pipeline, the dissolution tank is connected to the cooling dilution water pipeline via a second dilution water valve pipeline, and a second spray pipe bundle is provided inside the dissolution tank.
[0007] Preferably, a first spray pipe bundle is provided inside the drain tank.
[0008] The beneficial technical effects of the utility model are:
[0009] 1. Use dilution water to cool and dilute, which is achieved through spraying tube bundles. These tube bundles are composed of multiple DN15-25 short tubes with 0.3-0.5mm holes on the tube wall. This special design can effectively achieve the effect of diluting and condensing the mist.
[0010] 2. It is mainly composed of a drain tank, drain valve pipeline, sewage valve pipeline, dilution water valve pipeline and spray pipe bundle. The design is simple and practical, and can effectively perform steam draining and demisting.
[0011] 3. Through the spray tube bundle, not only the denitrification efficiency is improved, but also the emission of mist and impurities is effectively controlled to meet environmental protection requirements.
[0012] 4. The spray tube bundle can also clean and maintain the inside of the device to ensure the stability and reliability of the system and provide an efficient and environmentally friendly solution for industrial production. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Figure 1 This is a structural diagram of a denitrification and demisting device based on urea hydrolysis in this embodiment.
[0014] Figure numerals: 1. hydrolyzer, 2. steam valve pipeline, 3. sewage valve pipeline, 4. first spray pipe bundle, 5. dissolution tank, 6. first dilution water valve pipeline, 7. drain valve pipeline, 8. drain tank, 9. second dilution water valve pipeline, 10. second spray pipe bundle. DETAILED DESCRIPTION
[0015] In order to facilitate the understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. The embodiments described are given in the drawings. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thoroughly and comprehensively understood.
[0016] like Figure 1 As shown, a denitration and demisting device based on urea hydrolysis, the core part of which includes a hydrolyzer 1. A steam valve pipeline 2 is provided on one side of the heat exchange tube of the hydrolyzer 1 passing through one end of the hydrolyzer, which is used to control the inlet and outlet of steam to ensure the supply of heat source required for the hydrolysis reaction. Through the steam valve pipeline 2, steam is introduced into the heat exchange tube bundle of the hydrolyzer 1, indirectly heating the urea solution to raise its temperature to the required reaction temperature, thereby performing an effective hydrolysis reaction to generate ammonia.
[0017] The other side of the heat exchange tube of the hydrolyzer 1 passing through one end of the hydrolyzer is connected to the drain box 8 through the drain valve pipeline 7 to ensure the effective discharge and treatment of the drain, thereby maintaining the stable operation of the system. The drain box 8 is provided with a first spray pipe bundle 4, which is connected to the cooling dilution water pipeline through the first dilution water valve pipeline 6, and can evenly spray the cooling dilution water in the drain box 8, condense and dilute the drain steam, and prevent the fog from spreading in the workshop.
[0018] At the bottom of the hydrolyzer 1, the sewage valve pipeline 3 is connected to the dissolving tank 5 to treat the waste and impurities generated during the reaction. The dissolving tank 5 is also provided with a second spray pipe bundle 4, which is connected to the cooling dilution water pipeline through the second dilution water valve pipeline 9 to ensure the temperature control and substance concentration adjustment in the dissolving tank 5. The second spray pipe bundle 10 can evenly spray the cooling dilution water in the dissolving tank 5 to dilute and cool the high-temperature urea solution and prevent the spread of mist.
[0019] The dissolving tank 5 and the drain tank 8 are both connected to the cooling dilution water pipeline through the dilution water valve pipeline. This design ensures the temperature control and substance concentration adjustment inside the device, so that the entire system can operate in the best state.
[0020] The inside of the dissolving tank 5 and the drain box 8 are both provided with a spray pipe bundle, which is one of the important features of the device. The existence of the spray pipe bundle provides an additional processing function for the device. Specifically, the spray pipe bundle can spray the cooling dilution water evenly inside the dissolving tank 5 through its distributed nozzles, which helps the hydrolysis reaction of urea to proceed more fully, thereby improving the denitrification efficiency. In addition, the spray pipe bundle can also help remove mist and impurities to ensure that the emission standards meet environmental protection requirements. By spraying the cooling dilution water into the drain box 8 and the dissolving tank 5, the spray pipe bundle effectively reduces the temperature and concentration of the mist, prevents it from spreading in the workshop, and improves the working environment. The spray pipe bundle also has a cleaning function, which can regularly clean the dissolving tank 5 and the drain box 8 to prevent solid deposition and blockage, thereby maintaining the stable operation of the device. By regularly spraying cooling dilution water, the spray pipe bundle can effectively remove impurities attached to the inner wall and pipes of the dissolving tank 5, ensuring the long-term and efficient operation of the system.
[0021] When in use, saturated steam is used as a heat source. The steam enters the heat exchange tube bundle of the hydrolyzer 1 through the steam valve pipeline 2, and the urea solution enters the shell side of the hydrolyzer 1 from the bottom. The steam indirectly heats the urea solution in the steam valve pipeline 2, raising its temperature to about 150°C, thereby performing a hydrolysis reaction to generate ammonia. The temperature of the hydrophobic steam generated during the reaction is about 90-100°C, and all of these hydrophobic steam are introduced into the hydrophobic tank 8. In order to cool and dilute the steam in the hydrophobic tank and prevent the spread of fog, the upper first dilution water valve pipeline 6 will be opened, and the cooling dilution water will be sprayed into the hydrophobic tank 8 through the first spray tube bundle 4, thereby achieving the purpose of cooling and condensing the fog.
[0022] When the hydrolyzer 1 has an accidental discharge or needs to be shut down for maintenance, the sewage valve pipeline 3 is opened to discharge the urea solution in the hydrolyzer 1 that has not been completely reacted and has a high temperature into the dissolution tank 5. In order to prevent the mist generated by the high-temperature urea solution from spreading, the second dilution water valve pipeline 9 is also opened, and cooling dilution water is sprayed into the dissolution tank 5 through the second spray pipe bundle 10, thereby diluting and cooling the mist to prevent it from spreading into the workshop.
[0023] The above arrangement solves the problem of fog spreading in the workshop when the traditional device is directly discharged into the wastewater pool. This improvement not only improves the safety and environmental protection of the operation, but also significantly improves the working environment of the workshop and reduces the impact on the health of the operators.
[0024] The above-mentioned embodiments only express several implementation methods of the utility model, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the utility model patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the utility model, which all belong to the protection scope of the utility model. Therefore, the protection scope of the utility model patent shall be based on the attached claims.
Claims
1. A denitrification and demisting device based on urea hydrolysis, comprising a hydrolyzer (1), characterized in that: A steam valve pipeline (2) is provided on one side of one end of the heat exchange tube of the hydrolyzer passing through the hydrolyzer, and the other side is connected to a drain tank (8) via a drain valve pipeline (7), and the drain tank (8) is connected to a cooling dilution water pipeline via a first dilution water valve pipeline (6).
2. The denitrification and demisting device based on urea hydrolysis according to claim 1, characterized in that: The bottom of the hydrolyzer (1) is connected to a dissolving tank (5) via a sewage valve pipeline (3), the dissolving tank (5) is connected to a cooling dilution water pipeline via a second dilution water valve pipeline (9), and a second spray pipe bundle (10) is provided inside the dissolving tank (5).
3. The denitration and demisting device based on urea hydrolysis according to claim 2, characterized in that: A first spray pipe bundle (4) is arranged inside the drain box (8).