A urea plant tail gas absorber

Abstract

The utility model relates to urea tail gas treatment technical field, concretely relates to a kind of urea device tail gas absorber.The urea device tail gas absorber includes: bubble absorption section, bubble absorption section is along horizontal direction setting, bubble absorption section has absorption cavity in, absorption cavity has scrubbing liquid in, and gas-liquid separation zone is structured between the liquid level of scrubbing liquid and absorption cavity top, bubble absorption section has overflow hole, overflow hole is set below gas-liquid separation zone;Transition bin, transition bin is set in the top of bubble absorption section, transition bin is communicated with bubble absorption section, and tail gas discharge structure is set in transition bin, and tail gas in bubble absorption section enters tail gas discharge structure in through transition bin.The bubble absorption section design of horizontal structure greatly increases the section area of bubble escape, effectively reduces gas flow rate, avoids the liquid foam entrainment phenomenon due to flow rate is too high.

Description

Technical Field

[0001] This utility model relates to the field of urea tail gas treatment technology, specifically to a urea device tail gas absorber. Background Technology

[0002] In the medium-pressure absorption section of urea production, the tail gas discharged from the ammonia cooler at the top of the medium-pressure absorption tower contains a certain concentration of ammonia. A tail gas absorber is usually used to absorb the ammonia in the tail gas. The tail gas absorber washes the tail gas with an absorbent liquid, thereby absorbing and recovering the ammonia in the tail gas.

[0003] Traditional tail gas absorbers are typically vertical. At the bottom of the vertical tail gas absorber, ammonia-containing tail gas and absorbent liquid flow in separately from the last-stage ammonia cooler. The absorbent liquid mixes with the ammonia-containing tail gas and then flows upward along the vertical tail gas absorber. However, due to structural limitations, the vertical heat exchanger has a small diameter, resulting in a high gas velocity and a limited cross-sectional area for bubble escape, which easily leads to liquid entrainment. As a result, the ammonia absorption efficiency is greatly reduced. Summary of the Invention

[0004] This invention provides a tail gas absorber for a urea plant, which solves the problem that vertical heat exchangers, due to structural limitations, have a small diameter, resulting in high gas flow rates, limited bubble escape cross-sectional area, and easy liquid entrainment, thus significantly reducing ammonia absorption efficiency.

[0005] This utility model provides a tail gas absorber for a urea plant, comprising: The bubbling absorption section is arranged horizontally and has an absorption cavity containing washing liquid. A gas-liquid separation zone is constructed between the liquid level of the washing liquid and the top of the absorption cavity. The bubbling absorption section has an overflow hole located below the gas-liquid separation zone. A transition chamber is located at the top of the bubbling absorption section and is connected to the bubbling absorption section. An exhaust gas emission structure is provided inside the transition chamber, and the exhaust gas in the bubbling absorption section enters the exhaust gas emission structure through the transition chamber.

[0006] Beneficial effects: The horizontal bubbling absorption section design, compared to the traditional vertical structure, significantly increases the cross-sectional area for bubble escape, effectively reducing gas velocity and preventing liquid entrainment caused by excessive flow velocity. Simultaneously, this structure allows for more thorough contact between the washing liquid and the exhaust gas, improving the washing effect. The gas-liquid separation zone provides ample space for exhaust gas release, allowing liquid droplets in the exhaust gas to naturally fall back into the washing liquid under gravity.

[0007] In one optional embodiment, a gas-liquid separation structure is provided at the connection between the transition chamber and the bubbling absorption section, the gas-liquid separation structure being used to separate liquid from the exhaust gas.

[0008] Beneficial effects: The gas-liquid separation structure can separate and filter the exhaust gas, preventing it from entering the transition chamber before it is completely separated from the solution in the gas-liquid separation zone.

[0009] In one optional embodiment, a gas distribution structure is provided in the bubbling absorption section. The gas distribution structure is connected to the urea device so that the exhaust gas in the urea device enters the gas distribution structure. The gas distribution structure has multiple exhaust holes, and the exhaust gas in the gas distribution structure enters the absorption chamber through the multiple exhaust holes.

[0010] Beneficial effects: The gas distribution structure ensures that the exhaust gas is evenly distributed in the absorption chamber, achieving stable gas flow in the bubbling absorption section and avoiding local concentrations that are too high or too low. This improves the washing effect of the washing liquid on the exhaust gas and further enhances the exhaust gas treatment efficiency of the entire device.

[0011] In one optional embodiment, the overflow hole and the washing liquid inlet are respectively disposed on both sides of the bubbling absorption section, and a plurality of flow guiding structures are disposed in the bubbling absorption section. The plurality of flow guiding structures are disposed between the overflow hole and the washing liquid inlet, and adjacent flow guiding structures are staggered to form a flow guiding path.

[0012] Beneficial effects: By setting up a flow guiding structure, the washing liquid enters the bubbling absorption section from the washing liquid inlet and flows along the guiding path, increasing the flow path and time of the washing liquid in the bubbling absorption section. This allows the washing liquid to have more complete contact and reaction with the exhaust gas, improving the washing effect. At the same time, it completely eliminates the gas flow dead zone, significantly improving heat exchange efficiency and washing performance.

[0013] In one optional embodiment, the bubbling absorption section further includes a cooling structure, the cooling structure comprising a heat exchange tube arranged within the bubbling absorption section, the heat exchange tube containing a cooling medium, and the heat exchange tube being connected to a cooling system.

[0014] Beneficial effects: The cooling medium inside the heat exchange tube can exchange heat with dilute ammonia water, carrying away the heat from the dilute ammonia water and keeping it within a suitable temperature range. This ensures that the washing effect is not affected by excessively high temperatures, guaranteeing the stable operation and efficient washing performance of the exhaust gas absorber.

[0015] In one optional embodiment, the bubbling absorption section has tube boxes at both ends, one of the tube boxes being divided into a first chamber and a second chamber by a partition. The first chamber and the second chamber have a cooling medium inlet and a cooling medium outlet, respectively. The heat exchange tube includes a first heat exchange tube and a second heat exchange tube. The two ends of the first heat exchange tube are respectively connected to the first chamber and the other tube box, and the two ends of the second heat exchange tube are respectively connected to the second chamber and the other tube box.

[0016] Beneficial effects: By setting up the first and second heat exchange tubes, the heat exchange area and time between the cooling medium and the washing liquid are greatly increased, resulting in a more significant cooling effect. This allows for more effective control of the washing liquid temperature, ensuring that the washing liquid is always within the optimal washing temperature range, thereby guaranteeing the washing and absorption effect of the entire exhaust gas absorber on the exhaust gas.

[0017] In one optional embodiment, the transition chamber is connected to the buffer structure, and a pressure relief structure is provided at the connection between the transition chamber and the buffer structure. The buffer structure contains ammonia gas.

[0018] Beneficial effects: By incorporating a pressure relief structure, the hydrogen and oxygen in the exhaust gas can be effectively diluted, significantly improving the safety of the entire urea plant's exhaust gas treatment process. The transition chamber also buffers and stabilizes the exhaust gas flow, allowing it to enter subsequent treatment stages more smoothly, further enhancing the stability and reliability of the entire system.

[0019] In one optional embodiment, the pressure relief structure is a rupture disc, and the transition chamber has a fixing assembly for fixing the rupture disc. The fixing assembly includes a base plate and a fixing plate, and a mounting groove is formed between the base plate and the fixing plate. The rupture disc is disposed in the mounting groove and is fixedly connected to the base plate and the fixing plate by fasteners.

[0020] Beneficial effects: The fixing method of the base plate and the fixing plate is simple and easy to install and disassemble, which facilitates the regular inspection and replacement of the rupture disc. The base plate and the fixing plate are connected by fasteners, and the clamping force can be adjusted according to actual needs to ensure that the rupture disc is fixed firmly, thereby further improving the stability and safety of the entire device.

[0021] In one optional embodiment, the exhaust gas emission structure includes an air collection box and an exhaust pipe. The air collection box is fixedly installed inside the transition chamber. One end of the exhaust pipe is installed inside the transition chamber and communicates with the air collection box. The other end of the exhaust pipe is installed outside the transition chamber and communicates with the atmosphere. The air collection box has an exhaust gas inlet that communicates with the transition chamber.

[0022] Beneficial effects: The gas collection box can collect and buffer the exhaust gas, allowing it to be discharged more smoothly through the exhaust pipe. This avoids the impact and instability that may result from direct exhaust, further improving the stability and reliability of the entire device.

[0023] In one optional embodiment, the gas collection box is located on the side of the pressure relief structure away from the buffer structure, and a flow zone is formed between the gas collection box and the pressure relief structure. A tail gas flow hole is provided on the periphery of the gas collection box, and the tail gas in the transition chamber can enter the flow zone through the tail gas flow hole.

[0024] Beneficial effects: When the pressure in the flow zone increases to a certain level, the rupture disc breaks, and the exhaust gas in the transition chamber enters the buffer structure, where it mixes with the ammonia gas inside the buffer structure, thereby reducing the possibility of an explosion of the exhaust gas inside the transition chamber. Attached Figure Description

[0025] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of a tail gas absorber for a urea production device according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the transition compartment according to an embodiment of the present utility model; Figure 3 for Figure 2 A magnified view of part A in the diagram.

[0027] Explanation of reference numerals in the attached figures: 1. Bubbling absorption section; 101. Absorption chamber; 102. Gas-liquid separation zone; 103. Overflow hole; 104. Washing liquid inlet; 105. Flow guiding structure; 106. Tube box; 107. First chamber; 108. Second chamber; 109. Cooling structure; 1091. First heat exchange tube; 1092. Second heat exchange tube; 2. Transition chamber; 3. Tail gas emission structure; 301. Gas collection box; 302. Tail gas exhaust pipe; 303. Tail gas inlet; 4. Gas-liquid separation structure; 5. Gas distribution structure; 501. Exhaust hole; 6. Buffer structure; 601. Ammonia inlet; 602. Ammonia outlet; 603. Manhole; 7. Rupture disc; 8. Fixing assembly; 801. Base plate; 802. Fixing plate; 803. Mounting groove; 9. Flow zone; 10. Tail gas flow hole. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0029] The following is combined with Figures 1 to 3 The following describes embodiments of the present invention.

[0030] According to an embodiment of this utility model, a urea plant tail gas absorber is provided, comprising: a bubbling absorption section 1 and a transition chamber 2. The bubbling absorption section 1 is arranged horizontally and has an absorption chamber 101 containing a washing liquid. A gas-liquid separation zone 102 is formed between the level of the washing liquid and the top of the absorption chamber 101. The bubbling absorption section 1 has an overflow hole 103 located below the gas-liquid separation zone 102. The transition chamber 2 is located at the top of the bubbling absorption section 1 and has a tail gas emission structure 3. The transition chamber 2 is connected to the bubbling absorption section 1, and the tail gas in the bubbling absorption section 1 passes through the transition chamber 2 and enters the tail gas emission structure 3.

[0031] Specifically, the bubbling absorption section 1 has a horizontal structure and is located below the transition chamber 2. The exhaust gas inlet is located at the bottom of the bubbling absorption section 1. The exhaust gas enters the absorption chamber 101 from the bottom, is washed by the washing liquid, enters the transition chamber 2 from the top of the absorption chamber 101, and is discharged from the exhaust gas discharge structure 3. The washing liquid in the bubbling absorption section 1 is maintained at a specified level, so that a gas-liquid separation zone 102 is constructed between the washing liquid and the top of the absorption chamber 101. After being washed by the washing liquid, the exhaust gas rises to the gas-liquid separation zone 102. The gas-liquid separation zone 102 provides a gas phase space with sufficient longitudinal depth and radial width, allowing the exhaust gas to escape smoothly on a large area of ​​liquid surface under low gas velocity conditions, ensuring effective gas-liquid separation. Due to its low operating gas velocity, droplet entrainment can be significantly reduced. An overflow hole 103 is located below the gas-liquid separation zone 102. When the washing liquid level in the absorption chamber 101 rises to a certain height, excess washing liquid will flow out through the overflow hole 103, keeping the liquid level at a specified position. In this embodiment, the washing liquid is dilute ammonia.

[0032] The horizontal bubbling absorption section 1, compared to the traditional vertical structure, significantly increases the cross-sectional area for bubble escape, effectively reducing the gas velocity and avoiding liquid entrainment caused by excessive flow velocity. Simultaneously, this structure allows for more thorough contact between the washing liquid and the exhaust gas, improving the washing effect. The gas-liquid separation zone 102 provides ample space for the exhaust gas to release, allowing liquid droplets in the exhaust gas to naturally fall back into the washing liquid under gravity.

[0033] In one embodiment, a gas-liquid separation structure 4 is provided at the connection between the transition chamber 2 and the bubbling absorption section 1. The gas-liquid separation structure 4 is used to separate the liquid in the exhaust gas.

[0034] Specifically, such as Figure 3 As shown, the inlet of the transition chamber 2 is equipped with a gas-liquid separation structure 4. The gas-liquid separation structure 4 can separate and filter the exhaust gas, allowing the gas to enter the transition chamber 2 while the solution is isolated outside the transition chamber 2. The gas-liquid separation structure 4 can separate and filter the exhaust gas, preventing the exhaust gas from entering the transition chamber 2 without being completely separated from the solution in the gas-liquid separation zone 102.

[0035] In one embodiment, a gas distribution structure 5 is provided in the bubbling absorption section 1. The gas distribution structure 5 is connected to the urea device so that the exhaust gas in the urea device enters the gas distribution structure 5. The gas distribution structure 5 has multiple exhaust holes 501. The exhaust gas obtained in the gas distribution structure 5 enters the absorption chamber 101 through the multiple exhaust holes 501.

[0036] Specifically, such as Figure 1As shown, the gas distribution structure 5 is located at the bottom of the bubbling absorption section 1. The gas distribution structure 5 is connected to the tail gas inlet. The tail gas in the urea unit enters the gas distribution structure 5 through the tail gas inlet and then enters the absorption chamber 101 evenly through multiple exhaust holes 501, where it fully contacts and reacts with the dilute ammonia water in the absorption chamber 101. Adjacent exhaust holes 501 are spaced apart, and the number of exhaust holes 501 can be determined according to the length of the gas distribution structure 5 and the length of the bubbling absorption section 1.

[0037] The gas distribution structure 5 ensures that the exhaust gas is evenly distributed in the absorption chamber 101, and realizes the smooth flow of gas in the bubbling absorption section 1, avoiding local concentrations that are too high or too low, thereby improving the washing effect of the washing liquid on the exhaust gas and further improving the exhaust gas treatment efficiency of the entire device.

[0038] In one embodiment, the overflow hole 103 and the washing liquid inlet 104 are respectively disposed on both sides of the bubbling absorption section 1. The bubbling absorption section 1 is provided with a plurality of flow guiding structures 105. The plurality of flow guiding structures 105 are disposed between the overflow hole 103 and the washing liquid inlet 104, and adjacent flow guiding structures 105 are staggered to form a flow guiding path.

[0039] Specifically, such as Figure 1 As shown, the overflow hole 103 is located on the left side of the bubbling absorption section 1, and the washing liquid inlet 104 is located on the right side of the bubbling absorption section 1. The washing liquid inlet 104 is used to replenish the washing liquid into the absorption chamber 101. The flow guiding structure 105 is a baffle plate, and multiple baffle plates are arranged between the overflow hole 103 and the washing liquid inlet 104. Adjacent baffle plates are staggered to form a flow guiding path.

[0040] By setting the flow guiding structure 105, the washing liquid enters the bubbling absorption section 1 from the washing liquid inlet 104 and flows along the flow guiding path, which increases the flow path and time of the washing liquid in the bubbling absorption section 1, allowing the washing liquid to have more full contact and reaction with the exhaust gas, thus improving the washing effect.

[0041] In one embodiment, the bubbling absorption section 1 also includes a cooling structure 109, which includes a heat exchange tube arranged in the bubbling absorption section 1. The heat exchange tube contains a cooling medium and is connected to a cooling system.

[0042] Specifically, the heat exchange tubes contain a cooling medium. When the dilute ammonia water washes the exhaust gas, it generates a large amount of heat. The cooling medium inside the heat exchange tubes exchanges heat with the dilute ammonia water, carrying away the heat and maintaining the dilute ammonia water within a suitable temperature range. This ensures that the washing effect is not affected by excessively high temperatures. The cooling structure 109, through a rational layout of the heat exchange tubes, increases the contact area between the cooling medium and the dilute ammonia water, thereby improving heat exchange efficiency and more effectively controlling the temperature of the washing liquid. This ensures the stable operation and high-efficiency washing performance of the exhaust gas absorber.

[0043] In one embodiment, the bubbling absorption section 1 has tube boxes 106 at both ends, one of which is divided into a first chamber 107 and a second chamber 108 by a partition. The first chamber 107 and the second chamber 108 have a cooling medium inlet and a cooling medium outlet, respectively. The cooling structure 109 includes a first heat exchange tube 1091 and a second heat exchange tube 1092. The two ends of the first heat exchange tube 1091 are respectively connected to the first chamber 107 and the other tube box 106, and the two ends of the second heat exchange tube 1092 are respectively connected to the second chamber 108 and the other tube box 106.

[0044] Specifically, such as Figure 1 As shown, tube boxes 106 are respectively provided at the left and right ends of the bubbling absorption section 1. The tube box 106 at the left end of the bubbling absorption section 1 is divided into a first chamber 107 and a second chamber 108 by a partition. The first chamber 107 has a cooling medium inlet (not shown), and the second chamber 108 has a cooling medium outlet (not shown). Both the cooling medium inlet and the cooling medium outlet are connected to the cooling system (not shown) through pipelines. The first heat exchange tube 1091 is connected at both ends to the first chamber 107 and the tube box 106 at the right end of the bubbling absorption section 1, respectively. The second heat exchange tube 1092 is connected at both ends to the second chamber 108 and the tube box 106 at the right end of the bubbling absorption section 1, respectively. The cooling medium in the cooling system enters the first chamber 107 through the cooling medium inlet via the pipeline. The cooling medium then enters the first heat exchange tube 1091 from the first chamber 107, where it exchanges heat with the washing liquid in the absorption chamber 101. The cooling medium then enters the tube box 106 at the right end of the bubbling absorption section 1 along the first heat exchange tube 1091, and then enters the second heat exchange tube 1092, and enters the second chamber 108 along the second heat exchange tube 1092. Finally, it returns to the cooling system through the cooling medium outlet and pipeline. The cooling medium is water or heat transfer oil, and the cooling system is a circulating cooling water system or a heat transfer oil circulation system, etc.

[0045] By setting the first heat exchange tube 1091 and the second heat exchange tube 1092, the heat exchange area and heat exchange time between the cooling medium and the washing liquid are greatly increased, resulting in a more significant cooling effect. The temperature of the washing liquid can be controlled more effectively, ensuring that the washing liquid is always within the optimal washing temperature range, thereby guaranteeing the washing and absorption effect of the entire exhaust gas absorber on the exhaust gas.

[0046] In one embodiment, the transition chamber 2 is connected to the buffer structure 6, and a pressure relief structure is provided at the connection between the transition chamber 2 and the buffer structure 6. The buffer structure 6 contains ammonia gas.

[0047] Specifically, such as Figure 2 As shown, the exhaust gas after ammonia recovery enters the transition chamber 2, then flows through the transition chamber 2 into the exhaust gas emission structure 3 for further emission. A pressure relief structure is installed at the connection point between the transition chamber 2 and the buffer structure 6. After a certain period, the pressure relief structure opens, allowing the exhaust gas in the transition chamber 2 to enter the buffer structure 6 and mix with the ammonia in the buffer structure 6. This dilutes the concentration of hydrogen and oxygen in the exhaust gas, preventing an explosion due to excessive hydrogen and oxygen concentration. The pressure relief structure can be a rupture disc 7, a vent door, or a rupture cap. The buffer structure 6 is a vertical buffer cylinder with an ammonia inlet 601 and an ammonia outlet 602. The vertical buffer cylinder also has a manhole 603 for easy access by personnel for maintenance.

[0048] By incorporating a pressure relief structure, the hydrogen and oxygen in the exhaust gas are effectively diluted, significantly improving the safety of the entire urea plant's exhaust gas treatment process. The presence of transition chamber 2 also buffers and stabilizes the exhaust gas flow, allowing it to enter subsequent treatment stages more smoothly, further enhancing the stability and reliability of the entire system.

[0049] Furthermore, the volume ratio of the gas phase space above the overflow port to the buffer space of the vertical buffer cylinder is 1:11. A transition structure, which is funnel-shaped, connects the pressure relief structure to the smaller diameter end of the transition structure, and the vertical buffer cylinder to the larger diameter end of the transition structure. The volume ratio of the gas phase space above the overflow port and the gas phase space of the transition structure to the buffer space of the vertical buffer cylinder is 1:17.

[0050] In one embodiment, the pressure relief structure is a rupture disc 7, and the transition chamber 2 has a fixing component 8 for fixing the rupture disc 7. The fixing component 8 includes a base plate 801 and a fixing plate 802. An installation groove 803 is formed between the base plate 801 and the fixing plate 802. The rupture disc 7 is disposed in the installation groove 803 and is fixedly connected to the base plate 801 and the fixing plate 802 by fasteners.

[0051] Specifically, such as Figure 3As shown, both the base plate 801 and the fixing plate 802 are annular structures. The base plate 801 is fixed to the inner wall of the transition chamber 2, and the fixing plate 802 is positioned above the base plate 801. Both the base plate 801 and the fixing plate 802 have interlocking surfaces, and a mounting groove 803 is constructed between the interlocking surfaces of the base plate 801 and the fixing plate 802. The edge of the rupture disc 7 is positioned within the mounting groove 803. The base plate 801 and the fixing plate 802 are connected by fasteners, and a clamping force is applied to the edge of the rupture disc 7 to fix it. By setting a gas-liquid separation structure 4 at the inlet of the transition chamber 2, contact between the solution and the rupture disc 7 can be prevented, thereby slowing down the aging rate of the rupture disc 7. It should be noted that after the tail gas enters the buffer structure 6 and mixes with ammonia, it will enter the next process from the ammonia outlet 602. The ammonia mixed with the tail gas will not affect the urea production system, and the urea production system will not be shut down due to the failure of a single piece of equipment. Only the rupture disc needs to be replaced during shutdown maintenance.

[0052] The fixing method of the base plate 801 and the fixing plate 802 is simple and easy to install and disassemble, which facilitates the regular inspection and replacement of the rupture disc 7. The base plate 801 and the fixing plate 802 are connected by fasteners, and the clamping force can be adjusted according to actual needs to ensure that the rupture disc 7 is fixed firmly, thereby further improving the stability and safety of the entire device.

[0053] Furthermore, a pad (not shown) is provided between the rupture disc 7 and the base plate 801. The pad is fixed on the base plate 801, and the rupture disc 7 is placed on the pad. The pad can play a role in buffering and protection, avoiding direct contact between the rupture disc 7 and the base plate 801. When the rupture disc 7 is subjected to pressure, the pad can disperse some of the pressure, preventing the rupture disc 7 from rupturing prematurely due to excessive local stress.

[0054] In one embodiment, the exhaust gas emission structure 3 includes an air collection box 301 and an exhaust pipe 302. The air collection box 301 is fixedly installed in the transition chamber 2. One end of the exhaust pipe 302 is installed in the transition chamber 2 and communicates with the air collection box 301. The other end of the exhaust pipe 302 is installed outside the transition chamber 2 and communicates with the atmosphere. The air collection box 301 has an exhaust gas inlet 303 that communicates with the transition chamber 2.

[0055] Specifically, such as Figure 2 As shown, the gas collection box 301 is fixedly installed in the transition chamber 2. The gas collection box 301 has an exhaust gas inlet 303. The exhaust gas in the transition chamber 2 can enter the gas collection box 301 through the exhaust gas inlet 303, and the exhaust gas in the gas collection box 301 is discharged through the exhaust gas exhaust pipe 302.

[0056] The gas collection box 301 can collect and buffer the exhaust gas, allowing the exhaust gas to be discharged more smoothly through the exhaust pipe 302, avoiding the impact and instability that may be caused by direct exhaust gas emission, and further improving the stability and reliability of the entire device.

[0057] In one embodiment, the gas collection box 301 is located on the side of the pressure relief structure away from the buffer structure 6, and a flow zone 9 is constructed between the gas collection box 301 and the pressure relief structure. A tail gas flow hole 10 is provided on the periphery of the gas collection box 301, and the tail gas in the transition chamber 2 can enter the flow zone 9 through the tail gas flow hole 10.

[0058] Specifically, such as Figure 2 As shown, the gas collecting box 301 is located below the rupture disc 7, and a flow zone 9 is constructed between the gas collecting box 301 and the rupture disc 7. The exhaust gas in the transition chamber 2 can enter the flow zone 9 through the exhaust gas flow holes 10 on the periphery of the gas collecting box 301. When the pressure in the flow zone 9 increases to a certain level, the rupture disc 7 ruptures, and the exhaust gas in the transition chamber 2 enters the buffer structure 6, where it mixes with the ammonia gas in the buffer structure 6, thereby reducing the possibility of an explosion of the exhaust gas inside the transition chamber 2.

[0059] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A tail gas absorber for a urea plant, characterized in that, include: A bubbling absorption section (1) is arranged in a horizontal direction. The bubbling absorption section (1) has an absorption chamber (101) and a washing liquid in the absorption chamber (101). A gas-liquid separation zone (102) is constructed between the liquid level of the washing liquid and the top of the absorption chamber (101). The bubbling absorption section (1) has an overflow hole (103) which is located below the gas-liquid separation zone (102). Transition chamber (2) is located at the top of the bubbling absorption section (1). The transition chamber (2) is connected to the bubbling absorption section (1). A tail gas emission structure (3) is provided inside the transition chamber (2). The tail gas in the bubbling absorption section (1) enters the tail gas emission structure (3) through the transition chamber (2).

2. The urea plant tail gas absorber according to claim 1, characterized in that, A gas-liquid separation structure (4) is provided at the connection between the transition chamber (2) and the bubbling absorption section (1), and the gas-liquid separation structure (4) is used to separate the liquid in the exhaust gas.

3. The urea plant tail gas absorber according to claim 1 or 2, characterized in that, A gas distribution structure (5) is provided in the bubbling absorption section (1). The gas distribution structure (5) is connected to the urea device so that the exhaust gas in the urea device enters the gas distribution structure (5). The gas distribution structure (5) has multiple exhaust holes (501). The exhaust gas in the gas distribution structure (5) enters the absorption chamber (101) through the multiple exhaust holes (501).

4. The urea plant tail gas absorber according to claim 3, characterized in that, The overflow hole (103) and the washing liquid inlet (104) are respectively located on both sides of the bubbling absorption section (1). The bubbling absorption section (1) is provided with a plurality of flow guiding structures (105). The plurality of flow guiding structures (105) are located between the overflow hole (103) and the washing liquid inlet (104). Adjacent flow guiding structures (105) are staggered to form a flow guiding path.

5. The urea plant tail gas absorber according to claim 1, characterized in that, The bubbling absorption section (1) also has a cooling structure (109), which includes a heat exchange tube arranged in the bubbling absorption section (1). The heat exchange tube contains a cooling medium and is connected to a cooling system.

6. The urea plant tail gas absorber according to claim 5, characterized in that, The bubbling absorption section (1) has tube boxes (106) at both ends. One of the tube boxes (106) is divided into a first chamber (107) and a second chamber (108) by a partition. The first chamber (107) and the second chamber (108) have a cooling medium inlet and a cooling medium outlet, respectively. The heat exchange tube includes a first heat exchange tube (1091) and a second heat exchange tube (1092). The two ends of the first heat exchange tube (1091) are connected to the first chamber (107) and the other tube box (106), respectively. The two ends of the second heat exchange tube (1092) are connected to the second chamber (108) and the other tube box (106), respectively.

7. The urea plant tail gas absorber according to claim 1, characterized in that, The transition chamber (2) is connected to the buffer structure (6), and a pressure relief structure is provided at the connection between the transition chamber (2) and the buffer structure (6). The buffer structure (6) contains ammonia.

8. The urea plant tail gas absorber according to claim 7, characterized in that, The pressure relief structure is a rupture disc (7). The transition chamber (2) has a fixing component (8) for fixing the rupture disc (7). The fixing component (8) includes a base plate (801) and a fixing plate (802). An installation groove (803) is constructed between the base plate (801) and the fixing plate (802). The rupture disc (7) is disposed in the installation groove (803) and is fixedly connected to the base plate (801) and the fixing plate (802) by fasteners.

9. The urea plant tail gas absorber according to claim 8, characterized in that, The exhaust structure (3) includes an air collection box (301) and an exhaust pipe (302). The air collection box (301) is fixedly installed in the transition chamber (2). One end of the exhaust pipe (302) is installed in the transition chamber (2) and communicates with the air collection box (301). The other end of the exhaust pipe (302) is installed outside the transition chamber (2) and communicates with the atmosphere. The air collection box (301) has an exhaust inlet (303) that communicates with the transition chamber (2).

10. The urea plant tail gas absorber according to claim 9, characterized in that, The gas collection box (301) is located on the side of the pressure relief structure away from the buffer structure (6). A flow zone (9) is constructed between the gas collection box (301) and the pressure relief structure. A tail gas flow hole (10) is provided on the periphery of the gas collection box (301). The tail gas in the transition chamber (2) can enter the flow zone (9) through the tail gas flow hole (10).

Images