Gas inlet pretreatment triamine tail gas scrubbing column

Abstract

The utility model relates to a chemical equipment field, concretely relates to a kind of triamine tail gas washing tower of gas pretreatment, including tower body, washing subassembly, liquid circulating component and gas inlet flow uniformity component, triamine tail gas is pretreated by the gas inlet flow uniformity component being set in tower body, the separation of large particle in triamine tail gas and the uniformity of gas inlet are realized, avoid packing layer blockage, ensure that triamine tail gas is uniformly in tower body rising, and packing in packing layer is uniformly contacted, improve gas-liquid contact efficiency, reduce the gas ammonia content and dust particle in triamine tail gas, improve the washing effect of triamine tail gas washing tower.

Description

Technical Field

[0001] This utility model relates to the field of chemical equipment, specifically to a melamine tail gas scrubbing tower for inlet pretreatment. Background Technology

[0002] Melamine is an important organic chemical raw material widely used in industries such as wood, plastics, papermaking, flame retardants, clothing, and plastic foam. During melamine production, melamine granules enter a finished product storage silo, and the exhaust gas (containing ammonia and melamine dust) from the silo is sent to a melamine exhaust gas scrubbing tower for washing.

[0003] The melamine tail gas scrubbing tower is the core equipment for treating the aforementioned tail gas. Its working principle involves using water or dilute ammonia as the absorbent, which comes into counter-current contact with the tail gas inside the tower. Utilizing the high solubility of ammonia in water, the ammonia in the tail gas is absorbed and converted into ammonia water. Simultaneously, it washes away entrained melamine dust, ensuring the purified tail gas meets emission standards. In existing scrubbing towers, the tail gas is typically introduced directly into the tower through a single inlet pipe on the bottom sidewall. Due to inertia, the gas easily forms eccentric flow or vortices within the tower, resulting in uneven airflow distribution across the tower cross-section. Some areas have excessively high flow velocities and insufficient residence time, while other areas lack sufficient melamine tail gas flow, reducing gas-liquid contact efficiency. Utility Model Content

[0004] To address the aforementioned technical problems, this utility model provides a melamine tail gas scrubbing tower with inlet pretreatment. By pretreating the melamine tail gas with an inlet flow equalization component installed inside the tower, large particles in the melamine tail gas are separated and the inlet gas is made uniform. This avoids blockage of the packing layer, ensures that the melamine tail gas rises uniformly inside the tower and makes uniform contact with the packing material in the packing layer, improves the gas-liquid contact efficiency, reduces the ammonia content and dust particles in the melamine tail gas, and improves the scrubbing effect of the melamine tail gas scrubbing tower.

[0005] This utility model provides a melamine tail gas scrubbing tower for inlet gas pretreatment to solve the above-mentioned technical problems, comprising: The tower body has an exhaust pipe at the top and a tail gas inlet pipe on the bottom side wall that extends into the tower body and upwards from the outlet end. A washing assembly, located in the middle section of the tower body, includes at least one packing layer and a spray layer disposed on the packing layer; The liquid circulation assembly includes a circulation pipeline and a circulation pump installed on the circulation pipeline. The lower end of the circulation pipeline is connected to the liquid outlet at the bottom of the tower body, and the upper end is connected to the spray layer. The air intake flow equalization assembly includes an air intake hood supported by spokes in the lower section of the tower body. A drain pipe is provided on the lower side of the air intake hood. An exhaust gas inlet pipe is inserted into the drain pipe, and a cap is detachably provided between the exhaust gas inlet pipe and the drain pipe. The air intake hood is provided with a pre-dividing component that divides the inner cavity of the air intake hood into a first flow equalization chamber and a second flow equalization chamber. The pre-dividing component has an upwardly protruding central guide cavity corresponding to the exhaust gas inlet pipe's outlet end and an orifice plate provided on the peripheral wall of the central guide cavity. A flow equalization plate is provided on the upper side of the second flow equalization chamber, and a protruding pipe corresponding to the flow equalization holes on the flow equalization plate is provided on the upper side of the flow equalization plate.

[0006] Furthermore, the bottom of the air intake hood has a guide cone surface that slopes downward from the outer periphery of the air intake hood toward the drain pipe.

[0007] Furthermore, an inverted cone is also provided inside the central guide cavity.

[0008] Furthermore, a cap is fixed to the top of the protruding tube by a support rod.

[0009] Furthermore, the outer peripheral wall of the exhaust gas inlet pipe is provided with a first external thread, the inner peripheral wall of the sewage pipe is provided with a first internal thread, the cover has a central hole, the inner peripheral wall of the central hole is provided with a second internal thread that is threadedly engaged with the first external thread, and the outer peripheral wall of the cover is provided with a second external thread that is threadedly engaged with the first internal thread.

[0010] Furthermore, the lower end of the cover is provided with a limiting ring that can abut against the sewage pipe.

[0011] Furthermore, the washing components are arranged sequentially from top to bottom in the first spray section, the first packing section, the second spray section, and the second packing section inside the tower body. The circulation pipeline is provided with a first circulating liquid branch pipe, a second circulating liquid branch pipe, and an ammonia water output pipe. The first circulating liquid branch pipe extends into the first spray section and connects to the first spray pipe, and the second circulating liquid branch pipe extends into the second spray section and connects to the second spray pipe.

[0012] Furthermore, a heat exchanger is also provided on the circulation pipeline.

[0013] Furthermore, a wire mesh demister is provided above the second spray section, and a desalination pipe is provided on the upper side of the wire mesh demister.

[0014] The beneficial effects of this invention are as follows: the melamine tail gas is introduced into the tower body through the tail gas inlet pipe at the bottom of the tower body. Under the action of the inlet flow equalization component, the particles and dust in the melamine tail gas are removed, reducing the possibility that the dust in the melamine tail gas will mix with the washing liquid and form a slurry that blocks the packing layer. Furthermore, the melamine tail gas is evenly flowed, so that the melamine tail gas rises evenly in the tower body and flows through the washing component. After the melamine tail gas is washed and absorbed, the gaseous ammonia and dust particles in the melamine tail gas are further reduced, the gas-liquid contact efficiency is improved, the gaseous ammonia content and dust particles in the melamine tail gas are reduced, and the washing effect of the melamine tail gas washing tower is improved.

[0015] The air inlet hood of the air inlet flow equalization assembly is supported in the tower body by spokes, creating a gap between the air inlet hood and the inner wall of the tower body to provide a flow channel for the falling spray liquid. The drain pipe on the lower side of the air inlet hood is used to discharge dust particles separated from the melamine tail gas. The cap is used to seal the drain pipe and the air inlet tail pipe. The tail gas inlet pipe is inserted into the drain pipe. The melamine tail gas entering through the tail gas inlet pipe first enters the central guide cavity in the middle of the pre-dividing component. After impacting the top wall of the central guide cavity, the tail gas is forced to diffuse evenly in all directions. Then, it is blocked by the peripheral wall of the central guide cavity and bypasses the bottom edge of the central guide cavity. Then, it enters the second flow equalization cavity through the through holes on the orifice plate. After mixing upwards in the second flow equalization cavity, it is discharged from the flow equalization holes on the flow equalization plate. Through two-stage flow equalization, the melamine tail gas rises evenly in the tower body and comes into uniform contact with the packing in the packing layer, improving the melamine tail gas washing efficiency.

[0016] Meanwhile, during the flow equalization process of the melamine exhaust gas, large dust particles lose kinetic energy when they impact the top wall of the central guide cavity with the airflow and fall around the exhaust gas inlet pipe under gravity. Medium-sized dust particles diffuse outward with the airflow to the peripheral wall of the central guide cavity, impact the peripheral wall, lose kinetic energy, and fall. Some fine dust particles continue to move with the airflow to the bottom of the central guide cavity, where they separate from the airflow and fall as the airflow turns around the bottom of the central guide cavity. An inverted cone is installed inside the central guide cavity. After the airflow impacts the inverted cone, the dust particles impact the inclined surface of the cone and are deflected at an angle instead of falling vertically. This causes the dust particles to fall from a position near the inner wall of the central guide cavity. This method reduces the possibility that the separated dust particles will be lifted up by the airflow from the exhaust gas inlet pipe and fail to fall to the bottom of the first flow equalization cavity, thus improving the dust particle separation effect.

[0017] In summary, by using this invention to pretreat the melamine tail gas through the air inlet equalization component, not only can the dust particles in the melamine tail gas be separated, but the melamine tail gas can also rise evenly in the tower body. This not only reduces the risk of packing layer blockage, but also improves gas-liquid contact efficiency and enhances the washing effect of the melamine tail gas.

[0018] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is a schematic diagram of the intake flow equalization component of this utility model.

[0020] In the attached diagram: 10-Tower body, 11-Drain pipe, 12-Tail gas inlet pipe, 13-Liquid outlet, 21-First spray section, 21a-First spray pipe, 22-First packing section, 23-Second spray section, 23a-Second spray pipe, 24-Second packing section, 31-Circulation pipeline, 32-Circulation pump, 33-First circulating liquid branch pipe, 34-Second circulating liquid branch pipe, 35-Ammonia water output pipe, 36-Heat exchanger, 41-Air inlet hood, 41a-Guide cone surface, 42-Drain pipe, 43-Cap, 43a-Central hole, 43b-Limiting ring, 44a-Central guide cavity, 44b-Orifice plate, 45-Flow equalization plate, 46-Protruding pipe, 47-Cap, 48-Inverted cone, 50-Wire mesh demister, 60-Deionized water pipe. Detailed Implementation

[0021] Referring to the accompanying drawings, the specific embodiments of this utility model will be described in detail.

[0022] Reference Figures 1 to 2 A triamine tail gas scrubbing tower for inlet pretreatment includes a tower body 10, a scrubbing assembly, a liquid circulation assembly, and an inlet flow equalization assembly. The top of the tower body 10 has an exhaust pipe 11, and a manhole is provided on the side of the exhaust pipe 11 for easy maintenance of the tower body 10's interior. The bottom side wall of the tower body 10 has a tail gas inlet pipe 12 that extends into the tower body 10 and upwards from its outlet end. The triamine tail gas enters the inlet flow equalization assembly from the tail gas inlet pipe 12, achieving the removal of dust particles from the triamine tail gas and ensuring uniform flow before it rises evenly within the tower body 10. After being scrubbed by the scrubbing assembly, it is discharged from the exhaust pipe 11.

[0023] The washing assembly is located in the middle section of the tower body 10, and includes at least one packing layer and a spray layer disposed on the packing layer. The liquid circulation assembly includes a circulation pipe 31 and a circulation pump 32 disposed on the circulation pipe 31. The lower end of the circulation pipe 31 is connected to the liquid outlet 13 at the bottom of the tower body 10, and the upper end is connected to the spray layer. At this time, the circulating liquid flows out from the liquid outlet 13 at the bottom of the tower body 10, is pressurized by the circulation pump 32, and is sprayed from the spray layer onto the packing layer. Afterward, the circulating liquid flows back to the bottom of the tower body 10 and flows out again from the liquid outlet 13 at the bottom of the tower body 10, so that the circulating liquid can be reused. Furthermore, the washing components are arranged sequentially from top to bottom within the tower body 10 as a first spray section 21, a first packing section 22, a second spray section 23, and a second packing section 24. The circulation pipeline 31 is provided with a first circulating liquid branch pipe 33, a second circulating liquid branch pipe 34, and an ammonia water output pipe 35. A heat exchanger 36 is also provided on the circulation pipeline 31 for cooling the circulating liquid flowing out from the liquid outlet 13. The first circulating liquid branch pipe 33 extends into the first spray section 21 and connects to the first spray pipe 21a, and the second circulating liquid branch pipe 34 extends into the second spray section 23 and connects to the second spray pipe 23a. In this configuration, both the packing layer and the spray layer are configured in two sets. The circulating liquid flows out from the outlet 13 of the tower body 10, is pressurized by the circulating pump 32, cooled by the heat exchanger 36, and then flows into the first circulating liquid branch pipe 33 and the second circulating liquid branch pipe 34. It then passes through the first spray pipe 21a and is sprayed onto the first packing section 22, and the second spray pipe 23a and onto the second packing section 24. Afterward, the circulating liquid flows back to the bottom of the tower body 10 and flows out from the outlet 13 again. When the ammonia content in the circulating liquid is high, it can be discharged through the ammonia water output terminal. Of course, a water supply pipe is also provided on the circulating pipeline 31 to introduce circulating liquid from the outside. The first circulating liquid branch pipe 33, the second circulating liquid branch pipe 34, the ammonia water output pipe 35, and the water supply pipe are all equipped with valves to control the flow direction of the circulating liquid. By setting up two layers of packing and spray layers, the triamine tail gas can be washed and absorbed in two stages, reducing the ammonia and dust particles in the tail gas. Furthermore, a wire mesh demister 50 is provided above the second spray section 23, and a demineralized water pipe 60 is provided on the upper side of the wire mesh demister 50. At this time, the wire mesh demister 50 can reduce the formation of water mist, and the demineralized water pipe 60 is connected to a spiral sprayer. The spiral sprayer sprays demineralized water to reabsorb trace amounts of gaseous ammonia and dust in the melamine tail gas.

[0024] The air intake equalization assembly includes an air intake hood 41 supported by spokes in the lower section of the tower body 10. A gap exists between the air intake hood 41 and the inner wall of the tower body 10 to facilitate the return of circulating liquid to the bottom of the tower body 10. A drain pipe 42 is provided on the lower side of the air intake hood 41. Furthermore, the bottom of the air intake hood 41 has a guide cone surface 41a that slopes downwards from the outer periphery of the air intake hood 41 towards the drain pipe 42. Dust particles falling at the bottom of the air intake hood 41 can move along the guide cone surface 41a towards the drain pipe 42, facilitating the discharge of dust particles. The exhaust gas inlet pipe 12 is inserted into the drain pipe 42, and a detachable cap 43 is provided between the exhaust gas inlet pipe 12 and the drain pipe 42. The cap 43 is used to seal the drain pipe 42 and the air intake tailpipe. At this time, the radial cross-section of the exhaust gas inlet pipe 12 is smaller than that of the sewage pipe 42. After the cover 43 is removed, the separated dust particles can be discharged from the gap between the outer peripheral wall of the intake tailpipe and the inner peripheral wall of the sewage pipe 42. Preferably, the sewage pipe 42, the intake end of the exhaust gas inlet pipe 12, the intake hood 41, and the central guide cavity 44a are coaxially arranged, so that the intake air of the exhaust gas inlet pipe 12 can evenly impact the inverted cone 48 in the central guide cavity 44a and evenly diffuse radially. Further, the outer peripheral wall of the exhaust gas inlet pipe 12 is provided with a first external thread, the inner peripheral wall of the sewage pipe 42 is provided with a first internal thread, the cover 43 has a central hole 43a, the inner peripheral wall of the central hole 43a is provided with a second internal thread that is threadedly engaged with the first external thread, and the outer peripheral wall of the cover 43 is provided with a second external thread that is threadedly engaged with the first internal thread. At this point, the cap 43 is screwed between the exhaust inlet pipe 12 and the drain pipe 42, with the first external thread and the second internal thread connected, and the first internal thread and the second external thread connected, thus sealing the gap between the drain pipe 42 and the exhaust pipe. Furthermore, the lower end of the cap 43 is provided with a limiting ring 43b that can abut against the drain pipe 42. The limiting ring 43b can limit the screw-in position of the cap 43 while facilitating rotation of the cap 43.

[0025] The intake hood 41 is provided with a pre-dividing component that divides the inner cavity of the intake hood 41 into a first flow equalization cavity and a second flow equalization cavity. The pre-dividing component has an upwardly protruding central guide cavity 44a corresponding to the outlet end of the exhaust gas inlet pipe 12 and a perforated plate 44b on the peripheral wall of the central guide cavity 44a. Furthermore, the central guide cavity 44a is also provided with an inverted cone 48. With the setting of the inverted cone 48, after the melamine exhaust gas enters the first flow equalization cavity, it first impacts the inverted cone 48, and then deflects back along the conical surface of the inverted cone 48 and diffuses radially. At this time, the dust particles hit the inclined surface of the inverted cone 48 and are bounced off at an angle instead of falling vertically, so that the dust particles fall from the position near the inner wall of the central guide cavity 44a. In this way, the possibility that the separated dust particles are lifted up again by the airflow sprayed from the exhaust gas inlet pipe 12 and cannot fall into the bottom of the first flow equalization cavity can be reduced, thereby improving the dust particle separation effect.

[0026] A flow equalization plate 45 is provided on the upper side of the second flow equalization chamber. A protruding tube 46 corresponding to the flow equalization holes on the flow equalization plate 45 is provided on the upper side of the flow equalization plate 45. The protruding tube 46 on the flow equalization plate 45 is designed to prevent circulating fluid from falling onto the flow equalization plate 45 and entering the second flow equalization chamber through the flow equalization holes. Furthermore, a cap 47 is fixed to the top of the protruding tube 46 by a support rod. The cap 47 further prevents circulating fluid from falling into the second flow equalization chamber.

[0027] In this manner, the melamine tail gas entering through the tail gas inlet pipe 12 enters the first flow equalization chamber and first impacts the inverted cone 48 in the central flow guide chamber 44a. The airflow is deflected along the conical surface of the inverted cone 48, and after being radially dispersed, it is blocked by the peripheral wall of the central flow guide chamber 44a. Then, it flows along the inner wall of the central flow guide chamber 44a, bypasses the bottom edge of the central flow guide chamber 44a, and enters the second flow equalization chamber through the through holes on the orifice plate 44b. In the second flow equalization chamber, it is mixed upward and discharged from the flow equalization holes on the flow equalization plate 45, thus achieving gas equalization. This allows the melamine tail gas to rise evenly in the tower body 10 and make uniform contact with the packing in the packing layer. After two-stage washing, it passes through the wire mesh demister 50 and is then reabsorbed by demineralized water to remove trace amounts of gaseous ammonia and dust from the melamine tail gas. Finally, it is discharged from the exhaust pipe 11 at the top of the tower body 10, improving the washing efficiency of the melamine tail gas.

[0028] Meanwhile, after the dust particles collide with the inverted cone 48, they are bounced off at an angle. Some dust particles lose kinetic energy and fall from the edge of the central guide cavity 44a onto the guide cone surface 41a, moving towards the drain pipe 42. Some dust particles spread outward with the airflow to the peripheral wall of the central guide cavity 44a, collide with the peripheral wall of the central guide cavity 44a, lose kinetic energy, and fall. Some fine dust particles can continue to move with the airflow to the bottom of the central guide cavity 44a. When the airflow turns around the bottom of the central guide cavity 44a, they separate from the airflow and fall.

[0029] When it is necessary to clean the dust particles in the intake airflow equalization component, rotate the cover 43 to open the gap between the drain pipe 42 and the exhaust gas inlet pipe 12 to discharge the dust particles.

[0030] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0031] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A triamine tail gas scrubbing tower for inlet pretreatment, characterized in that, include: The tower body (10) has an exhaust pipe (11) at the top and a tail gas inlet pipe (12) on the bottom side wall that extends into the tower body (10) and extends upward at the outlet end. The washing assembly is located in the middle section of the tower body (10) and includes at least one packing layer and a spray layer disposed on the packing layer; The liquid circulation assembly includes a circulation pipeline (31) and a circulation pump (32) installed on the circulation pipeline (31). The lower end of the circulation pipeline (31) is connected to the liquid outlet (13) at the bottom of the tower body (10), and the upper end is connected to the spray layer. The air intake equalization assembly includes an air intake hood (41) supported by spokes in the lower section of the tower body (10). A drain pipe (42) is provided on the lower side of the air intake hood (41). The exhaust gas inlet pipe (12) is inserted into the drain pipe (42), and a cap (43) is detachably provided between the exhaust gas inlet pipe (12) and the drain pipe (42). The air intake hood (41) is provided with a pre-dividing component that divides the inner cavity of the air intake hood (41) into a first equalization cavity and a second equalization cavity. The pre-dividing component has an upwardly protruding central guide cavity (44a) corresponding to the exhaust end of the exhaust gas inlet pipe (12) and a perforated plate (44b) on the peripheral wall of the central guide cavity (44a). A equalization plate (45) is provided on the upper side of the second equalization cavity. A protruding pipe (46) corresponding to the equalization hole on the equalization plate (45) is provided on the upper side of the equalization plate (45).

2. The melamine tail gas scrubbing tower for inlet pretreatment according to claim 1, characterized in that, The bottom of the air intake hood (41) has a guide cone surface (41a) that slopes downward from the outer periphery of the air intake hood (41) toward the drain pipe (42).

3. The melamine tail gas scrubbing tower for inlet pretreatment according to claim 1, characterized in that, The central guide cavity (44a) is also provided with an inverted cone (48).

4. The melamine tail gas scrubbing tower for inlet pretreatment according to claim 1, characterized in that, The top of the protruding tube (46) is fixed with a cap (47) by a support rod.

5. The melamine tail gas scrubbing tower for inlet pretreatment according to claim 1, characterized in that, The outer peripheral wall of the exhaust gas inlet pipe (12) is provided with a first external thread, the inner peripheral wall of the sewage pipe (42) is provided with a first internal thread, the cover (43) has a central hole (43a), the inner peripheral wall of the central hole (43a) is provided with a second internal thread that is threadedly engaged with the first external thread, and the outer peripheral wall of the cover (43) is provided with a second external thread that is threadedly engaged with the first internal thread.

6. The melamine tail gas scrubbing tower for inlet pretreatment according to claim 5, characterized in that, The lower end of the cover (43) is provided with a limiting ring (43b) that can abut against the drain pipe (42).

7. The melamine tail gas scrubbing tower for inlet pretreatment according to claim 1, characterized in that, The washing components are arranged from top to bottom in the first spray section (21), the first packing section (22), the second spray section (23), and the second packing section (24) inside the tower body (10). The circulation pipeline (31) is provided with a first circulating liquid branch pipe (33), a second circulating liquid branch pipe (34) and an ammonia water output pipe (35). The first circulating liquid branch pipe (33) extends into the first spray section (21) and is connected to the first spray pipe (21a). The second circulating liquid branch pipe (34) extends into the second spray section (23) and is connected to the second spray pipe (23a).

8. The melamine tail gas scrubbing tower for inlet pretreatment according to claim 7, characterized in that, A heat exchanger (36) is also provided on the circulation pipeline (31).

9. The melamine tail gas scrubbing tower for inlet pretreatment according to claim 7, characterized in that, A wire mesh demister (50) is also provided above the second spray section (23), and a desalination pipe (60) is also provided on the upper side of the wire mesh demister (50).

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