Multi-stage treatment assembly for emptied tail gas of urea low-pressure absorption tower

Abstract

The utility model belongs to the technical field of tail gas treatment equipment, and particularly relates to an emptying tail gas multistage treatment assembly of a urea low-pressure absorption tower, which comprises a first-stage absorption tower and a second-stage absorption tower, a circulating pipeline is fixedly connected between the first-stage absorption tower and the second-stage absorption tower, and the left side of the first-stage absorption tower is fixedly connected with an ammonia gas inlet pipe. The right side of the secondary absorption tower is fixedly connected with an absorption liquid inlet pipe, and the top of the secondary absorption tower is fixedly connected with an emptying cylinder. By designing the combination of two stages of absorption towers, namely the first-stage absorption tower and the second-stage absorption tower, a gas phase of the first-stage absorption tower is discharged to the second-stage absorption tower to be continuously absorbed, then ammonia water generated after absorption liquid of the first-stage absorption tower is used is discharged to an ammonia water outlet, and inert gas after absorption is discharged to an emptying cylinder through the second-stage absorption tower to be emptied; and finally, desalted water with lower temperature is used for absorbing ammonia gas, so that the ammonia content of discharged tail gas can be greatly reduced, the environmental protection pressure is reduced, and the environmental quality is improved.

Description

Technical Field

[0001] This solution belongs to the field of exhaust gas treatment equipment, specifically involving a multi-stage exhaust gas treatment component for a urea low-pressure absorption tower. Background Technology

[0002] In the carbon dioxide stripping urea production process, the ammonia content in the exhaust gas mainly comes from the ammonia in the exhaust gas emitted from the atmospheric pressure tower and the low-pressure absorption tower within the unit.

[0003] A search revealed that a utility model patent with authorization announcement number CN201085981Y discloses a section of ammonia absorption tower for a urea production unit, which has a washing section and a bubbling section arranged vertically. The washing section is provided with several trays, and the bubbling section is provided with a medium distributor. The bubbling section is also provided with a secondary medium distributor composed of several perforated plates, which is located above the medium distributor. The diameter of the medium flow holes on each perforated tray decreases from bottom to top.

[0004] However, with existing technologies, the ammonia content in the exhaust gas emitted after absorption by low-pressure absorption towers is still relatively high, which increases the environmental burden on enterprises. Utility Model Content

[0005] The purpose of this solution is to provide a multi-stage treatment component for the vent gas of a urea low-pressure absorption tower, in order to solve the problem that the ammonia content in the exhaust gas emitted after absorption by the low-pressure absorption tower is still relatively high in the existing technology.

[0006] To achieve the above objectives, this solution provides a multi-stage treatment component for the venting tail gas of a urea low-pressure absorption tower, comprising a primary absorption tower and a secondary absorption tower. A circulation pipeline is fixedly connected between the primary and secondary absorption towers. An ammonia inlet pipe is fixedly connected to the left side of the primary absorption tower, and an absorbent liquid inlet pipe is fixedly connected to the right side of the secondary absorption tower. A venting cylinder is fixedly connected to the top of the secondary absorption tower, and an ammonia water outlet is fixedly connected to the bottom of the primary absorption tower.

[0007] The principle of this scheme is as follows: During operation, the absorbent in the primary absorption tower comes from the circulating liquid in the secondary absorption tower, and the absorbent in the secondary absorption tower comes from the demineralized water in the demineralized water pipeline network. The gas phase of the primary absorption tower is discharged to the secondary absorption tower for further absorption. After use, the absorbent in the primary absorption tower is discharged to the ammonia outlet, while the inert gas after absorption is discharged to the venting cylinder through the secondary absorption tower. Finally, the ammonia gas is absorbed using demineralized water at a lower temperature, which can greatly reduce the ammonia content in the exhaust gas, alleviate environmental pressure, and improve environmental quality. The ammonia water produced in the primary absorption tower can be discharged through the ammonia water outlet and finally enters the ammonia water tank through the connecting pipe. Before the ammonia water is discharged, it can be filtered by the filter plate. At the same time, the impact force of the falling ammonia water can make the impeller rotate, thereby making the steel brush coaxial with the impeller clean the filter plate and prevent large particulate impurities from clogging the filter plate. Later, it is only necessary to push the sleeve to separate the sleeve and the clips on the sleeve from the hollow sleeve, and then remove the hollow sleeve to clean the particulate matter filtered by the filter plate.

[0008] The technical advantages of this solution are as follows: By designing a combination of two absorption towers, namely a primary absorption tower and a secondary absorption tower, both of which are structured packed towers, the absorbent in the primary absorption tower comes from the circulating liquid in the secondary absorption tower, while the absorbent in the secondary absorption tower comes from the demineralized water from the demineralized water pipeline network. The gas phase from the primary absorption tower is discharged to the secondary absorption tower for further absorption. Then, the ammonia water generated after the absorbent in the primary absorption tower is discharged to the ammonia water outlet, while the inert gas after absorption is discharged to the venting cylinder through the secondary absorption tower. Finally, the ammonia gas is absorbed using demineralized water at a lower temperature, which can greatly reduce the ammonia content in the exhaust gas, alleviate environmental protection pressure, and improve environmental quality.

[0009] The ammonia outlet of the primary absorption tower is designed in two sections: an ammonia outlet and a connecting pipe, which are fixed together by a connecting frame. A hollow sleeve that is easy to disassemble is installed between the two sections. The hollow sleeve contains a filter and anti-clogging mechanism, in which the generated ammonia is filtered through a filter plate, facilitating further treatment and recycling of the ammonia.

[0010] Furthermore, a connecting frame is fixedly connected to the outer wall of the ammonia outlet, and a connecting pipe is fixedly connected to the end of the connecting frame. Baffles are fixedly connected to both the connecting pipe and the ammonia outlet. A hollow sleeve is slidably connected between the two baffles, and a filter anti-clogging mechanism is provided on the inner side of the hollow sleeve.

[0011] Furthermore, both the connecting pipe and the ammonia outlet are slidably fitted with retaining sleeves on their outer sides. These retaining sleeves are slidably connected to the hollow sleeve, and retaining strips are fixedly connected to the inner wall of the retaining sleeve. These retaining strips engage with the hollow sleeve. A sliding sleeve is fixedly connected to the baffle plate, and a slider is slidably connected to the inner side of the sliding sleeve. The slider is fixedly connected to the inner surface of the retaining sleeve. A ring of grooves is distributed around the outer wall of the hollow sleeve for the retaining strips to engage, thus fixing the installation position of the hollow sleeve.

[0012] Furthermore, a spring is provided on the inner side of the sliding sleeve. One end of the spring is fixedly connected to the slider, and the other end of the spring is fixedly connected to the inner surface of the sliding sleeve. By providing the spring, the reaction force can be applied to the sleeve via the slider.

[0013] Furthermore, the filtration anti-clogging mechanism includes a filter plate fixedly connected to the inside of the hollow sleeve. A rotating shaft is mounted on the middle of the filter plate via a bearing. An impeller is fixedly connected to the top of the rotating shaft. A connecting rod is fixedly connected to the middle section of the rotating shaft. A hollow shell is fixedly connected to the end of the connecting rod. A sliding seat is slidably connected to the inside of the hollow shell. A steel brush is fixedly connected to the bottom of the sliding seat, and the steel brush is in contact with the filter plate. Through the design of the filtration anti-clogging mechanism, the ammonia water condensed in the primary absorption tower is effectively filtered.

[0014] Furthermore, the slide block is provided with ball bearings on its side, and these ball bearings contact the inner surface of the hollow shell. The ball bearings reduce the relative friction between the slide block and the hollow shell.

[0015] Furthermore, a second spring is provided on the inner side of the hollow shell. One end of the second spring is fixedly connected to the slide block, and the other end of the second spring is fixedly connected to the inner surface of the hollow shell. By providing the second spring, the elastic force can be applied to the steel brush through the slide block, ensuring that it remains in contact with the filter plate. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of an embodiment of the present utility model.

[0017] Figure 2 This is an embodiment of the present utility model. Figure 1 A schematic diagram of the hollow sleeve structure;

[0018] Figure 3 This is an embodiment of the present utility model. Figure 1 A partial structural front sectional view;

[0019] Figure 4 This is an embodiment of the present utility model. Figure 3 A magnified view of the local structure;

[0020] Figure 5This is an embodiment of the present utility model. Figure 4 Enlarged view of point A;

[0021] Figure 6 This is an embodiment of the present utility model. Figure 4 Enlarged view of point B.

[0022] The following detailed explanation illustrates the specific implementation methods:

[0023] The reference numerals in the accompanying drawings of the instruction manual include: primary absorption tower 1, secondary absorption tower 2, ammonia inlet pipe 101, circulation pipeline 102, absorbent inlet pipe 201, venting cylinder 202, ammonia outlet 3, baffle 4, connecting pipe 5, connecting frame 6, hollow sleeve 7, filter anti-clogging mechanism 8, clamping sleeve 9, clamping strip 10, sliding sleeve 11, slider 12, spring one 13, filter plate 81, rotating shaft 82, impeller 83, connecting rod 84, hollow shell 85, sliding seat 86, steel brush 87, spring two 88, ball bearing 89. Detailed Implementation

[0024] The basic implementation examples are as follows: Figures 1-6 As shown: A multi-stage venting tail gas treatment component for a urea low-pressure absorption tower includes a primary absorption tower 1 and a secondary absorption tower 2. Both the primary absorption tower 1 and the secondary absorption tower 2 are structured packed towers. A circulation pipeline 102 is fixedly connected between the primary absorption tower 1 and the secondary absorption tower 2. An ammonia inlet pipe 101 is fixedly connected to the left side of the primary absorption tower 1, and an absorbent liquid inlet pipe 201 is fixedly connected to the right side of the secondary absorption tower 2. A venting cylinder 202 is fixedly connected to the top of the secondary absorption tower 2. An ammonia outlet 3 is fixedly connected to the bottom of the primary absorption tower 1. A connecting frame 6 is fixedly connected to the outer wall of the ammonia outlet 3. A connecting pipe 5 is fixedly connected to the end of the connecting frame 6. Baffles 4 are fixedly connected to both the connecting pipe 5 and the ammonia outlet 3. A hollow sleeve 7 is slidably connected between the two baffles 4.

[0025] like Figure 4 , Figure 5 As shown, ferrules 9 are slidably fitted onto the outer sides of both the connecting pipe 5 and the ammonia outlet 3. The ferrules 9 are slidably connected to the hollow sleeve 7. A retaining strip 10 is fixedly connected to the inner wall of the ferrule 9, engaging with the hollow sleeve 7. A sliding sleeve 11 is fixedly connected to the baffle 4, and a slider 12 is slidably connected to the inner side of the sliding sleeve 11, fixedly connected to the inner surface of the ferrule 9. A ring of grooves is formed on the outer wall of the hollow sleeve 7 for engaging the retaining strip 10, thus fixing the installation position of the hollow sleeve 7. A spring 13 is provided on the inner side of the sliding sleeve 11, one end of which is fixedly connected to the slider 12, and the other end is fixedly connected to the inner surface of the sliding sleeve 11. Through the spring 13, the reaction force can be applied to the ferrule 9 via the slider 12.

[0026] like Figure 4, Figure 6 As shown, a filter anti-clogging mechanism 8 is provided inside the hollow sleeve 7. This mechanism filters the ammonia water condensed in the primary absorption tower 1. The filter anti-clogging mechanism 8 includes a filter plate 81 fixedly connected to the inside of the hollow sleeve 7. A rotating shaft 82 is mounted on the middle of the filter plate 81 via a bearing. An impeller 83 is fixedly connected to the top of the rotating shaft 82. A connecting rod 84 is fixedly connected to the middle section of the shaft of the rotating shaft 82. A hollow shell 85 is fixedly connected to the end of the connecting rod 84. A slide block 86 is slidably connected to the inside of the hollow shell 85. A steel brush 87 is fixedly connected to the bottom of the slide block 86, and the steel brush 87 contacts the filter plate 81. Ball bearings 89 are provided on the side of the slide block 86, and these ball bearings 89 contact the inner surface of the hollow shell 85. The ball bearings 89 reduce the relative friction between the slide block 86 and the hollow shell 85. A second spring 88 is provided on the inner side of the hollow shell 85. One end of the second spring 88 is fixedly connected to the slide 86, and the other end of the second spring 88 is fixedly connected to the inner surface of the hollow shell 85. By setting the second spring 88, the elastic force can be applied to the steel brush 87 through the slide 86, so that it is always in contact with the filter plate 81.

[0027] The specific implementation process of this utility model is as follows: During use, the absorbent in the primary absorption tower 1 comes from the circulating liquid in the secondary absorption tower 2, which in turn comes from the demineralized water from the demineralized water pipeline network. The gas phase from the primary absorption tower 1 is discharged to the secondary absorption tower 2 for further absorption. After use, the absorbent in the primary absorption tower 1 is discharged to the ammonia outlet 3, while the absorbed inert gas is discharged through the secondary absorption tower 2 to the venting cylinder 202. Finally, the ammonia gas is absorbed using demineralized water at a lower temperature, which can significantly reduce the ammonia content in the exhaust gas, alleviate environmental pressure, and improve environmental quality. The ammonia water produced in the collecting tower 1 can be discharged through the ammonia water outlet 3 and finally enters the ammonia water tank through the connecting pipe 5. Before the ammonia water is discharged, it can be filtered by the filter plate 81. At the same time, the impact force of the falling ammonia water can make the impeller 83 rotate, thereby making the steel brush 87 coaxial with the impeller 83 clean the filter plate 81 and prevent large particles of impurities from clogging the filter plate 81. Later, simply push the sleeve 9 to separate the sleeve 9 and the clip 10 on the sleeve 9 from the hollow sleeve 7, and then take out the hollow sleeve 7 to clean the particles filtered by the filter plate 81.

[0028] This scheme designs a combination of two absorption towers: a primary absorption tower 1 and a secondary absorption tower 2. Both primary and secondary absorption towers are structured packed towers. The absorbent in primary absorption tower 1 comes from the circulating liquid in secondary absorption tower 2, while the absorbent in secondary absorption tower 2 comes from the demineralized water from the demineralized water pipeline network. The gas phase from primary absorption tower 1 is discharged to secondary absorption tower 2 for further absorption. The ammonia water generated after the use of the absorbent in primary absorption tower 1 is discharged to ammonia water outlet 3, while the inert gas after absorption is discharged to venting cylinder 202 via secondary absorption tower 2. Finally, the ammonia gas is absorbed using demineralized water at a lower temperature, which can greatly reduce the ammonia content in the exhaust gas, alleviate environmental protection pressure, and improve environmental quality.

[0029] The ammonia outlet 3 of the primary absorption tower 1 is set in a two-section configuration, namely the ammonia outlet 3 and the connecting pipe 5, and the two are fixed together by the connecting frame 6. In addition, a hollow sleeve 7 that is easy to disassemble and assemble is set between the two. The hollow sleeve 7 is equipped with a filter anti-clogging mechanism 8, in which the generated ammonia water is filtered through the filter plate 81, which facilitates the further treatment and recycling of the ammonia water.

[0030] The above descriptions are merely embodiments of this utility model, and common knowledge regarding specific structures and characteristics is not elaborated upon here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the structure of this utility model, and these should also be considered within the scope of protection of this utility model. These modifications will not affect the effectiveness of the implementation of this utility model or the practicality of the patent. The scope of protection claimed in this application shall be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A multi-stage treatment assembly for vent gas of a urea low-pressure absorption tower, comprising a first-stage absorption tower and a second-stage absorption tower, characterized in that: The primary absorption tower and secondary absorption tower are fixedly connected with a circulating pipeline, the left side of the primary absorption tower is fixedly connected with an ammonia gas inlet pipe, the right side of the secondary absorption tower is fixedly connected with an absorption liquid inlet pipe, the top of the secondary absorption tower is fixedly connected with a venting cylinder, and the bottom of the primary absorption tower is fixedly connected with an ammonia water outlet.

2. The multi-stage vent gas treatment assembly for a urea low-pressure absorption tower according to claim 1, characterized in that: The outer wall of the ammonia water outlet is fixedly connected with a connecting frame, the tail end of the connecting frame is fixedly connected with a butt joint pipe, the butt joint pipe and the ammonia water outlet are fixedly connected with baffles, a hollow sleeve is slidably connected between the two baffles, and a filter anti-blocking mechanism is arranged on the inner side of the hollow sleeve.

3. The multi-stage vent gas treatment assembly for a urea low-pressure absorption tower according to claim 2, characterized in that: The outer side of the butt joint pipe and the ammonia water outlet is slidably sleeved with a clamping sleeve, the clamping sleeve is slidably connected with the hollow sleeve, the inner wall of the clamping sleeve is fixedly connected with a clamping strip, the clamping strip is clamped with the hollow sleeve, the baffle is fixedly connected with a sliding sleeve, the inner side of the sliding sleeve is slidably connected with a sliding block, and the sliding block is fixedly connected to the inner surface of the clamping sleeve.

4. The multi-stage vent gas treatment assembly for a urea low-pressure absorption column according to claim 3, characterized in that: The inner side of the sliding sleeve is provided with a spring one, one end of the spring one is fixedly connected with the sliding block, and the other end of the spring one is fixedly connected to the inner surface of the sliding sleeve.

5. The multi-stage vent gas treatment assembly for a urea low-pressure absorption column according to claim 2, characterized in that: The filter anti-blocking mechanism comprises a filter plate fixedly connected to the inner side of the hollow sleeve, a rotating shaft is installed in the middle of the filter plate through a bearing, a impeller is fixedly connected to the top of the rotating shaft, a connecting rod is fixedly connected to the shaft body middle segment of the rotating shaft, a hollow shell is fixedly connected to the tail end of the connecting rod, a sliding seat is slidably connected to the inner side of the hollow shell, a steel brush is fixedly connected to the bottom of the sliding seat, and the steel brush is in contact with the filter plate.

6. The multi-stage vent gas treatment assembly for a urea low-pressure absorption column according to claim 5, characterized in that: The side of the sliding seat is provided with a ball, and the ball is in contact with the inner surface of the hollow shell.

7. The multi-stage vent gas treatment assembly for a urea low-pressure absorption column according to claim 5, characterized in that: The inner side of the hollow shell is provided with a spring two, one end of the spring two is fixedly connected with the sliding seat, and the other end of the spring two is fixedly connected to the inner surface of the hollow shell.

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