Apparatus for reducing ammonia emissions in a urea process

Abstract

This utility model discloses a device for reducing ammonia emissions in a urea process, relating to the technical field of ammonia emission reduction devices. It includes a tank with a liquid outlet at the lower end of one side, multiple water pipes on the outer wall of the other side, an air inlet at the lower middle of the outer wall, and an air outlet at the middle of the top of the tank. This utility model utilizes the tank in conjunction with three spray pipes, extension pipes, and spray heads positioned at different locations. The spray pipes are staggered from top to bottom along the middle of the inner wall of the tank, the extension pipes extend to both sides of the tank and abut against the inner wall, and the spray heads are evenly arranged on the extension pipes. This facilitates the coverage of the entire tank by the spray liquid, improving the uniformity of the spray coverage. Ultimately, it solves the problem of insufficient spray volume at the tank edges and upper and lower areas due to the use of a single horizontal spray pipe in existing devices, resulting in ammonia-containing exhaust gas being discharged before sufficient contact with the spray liquid. This improves the ammonia absorption efficiency and resource recovery rate, helping the urea process meet environmental emission standards.

Description

Technical Field

[0001] This utility model relates to the technical field of devices for reducing ammonia emissions, and in particular to a device for reducing ammonia emissions in a urea process. Background Technology

[0002] In the urea production process, ammonia is a core raw material that participates in the synthesis reaction. However, the production process generates ammonia-containing tail gas. If it is directly discharged, it will not only waste ammonia resources but also cause air pollution. At the same time, ammonia dissolves in water to form alkaline wastewater, which will corrode subsequent treatment equipment and disrupt the ecological balance of water bodies. Therefore, efficient recovery and treatment of ammonia emissions in the urea process is a key link in achieving both environmental protection standards and resource conservation. Existing devices mostly use a single horizontal spray pipe, with spray heads only installed near the central axis of the tank. The spray liquid is sprayed in a columnar or local fan-shaped pattern, and the amount that can be sprayed on the edge and upper and lower areas of the tank is relatively small. When ammonia-containing tail gas enters from the air inlet in the middle of the tank, some of the tail gas is discharged from the air outlet at the top without fully contacting the spray liquid. Therefore, the above problems need to be improved. Utility Model Content

[0003] The purpose of this invention is to address the shortcomings of existing technologies by proposing a device for reducing ammonia emissions in the urea process.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: a device for reducing ammonia emissions in a urea process, comprising a tank, a liquid outlet at the lower end of one side of the tank, multiple water pipes on the outer wall of the other side of the tank, an air inlet at the lower end of the middle of the outer wall of the tank, an air outlet at the middle of the top of the tank, three spray pipes in different directions arranged sequentially from top to bottom on the middle of the inner wall of the tank, a water storage tank at the bottom of the inner wall of the tank, and an adjustment component installed inside the tank between the spray pipes and the air inlet.

[0005] Preferably, multiple extension pipes that abut against the inner wall of the tank are provided at equal intervals on both sides of the spray pipe, and multiple spray heads are provided at equal intervals on the outer wall of one side of the extension pipe. One end of the spray pipe is connected to the upper end of multiple water supply pipes in a corresponding manner, and the lower end of the water supply pipe is connected to the inside of the water storage tank. A water inlet is opened at one point on the inner wall of the water storage tank.

[0006] Preferably, a baffle plate is provided inside the tank at the upper end of the air inlet.

[0007] Preferably, a liquid collecting hopper is provided on the inner wall of the tank at the lower end of the air inlet, and a liquid outlet pipe is provided between the bottom end of the liquid collecting hopper and the liquid outlet.

[0008] Preferably, the adjusting assembly includes multiple rotating rods rotatably arranged at equal intervals on the inner wall of the tank. A guide plate is fixedly connected to the bottom surface of each rotating rod. A reciprocating gear is coaxially fixed to the middle of the rotating rod. A sliding rack meshes with the upper end of the reciprocating gear. A tooth groove is formed in the middle of the top surface of the sliding rack. An explosion-proof box is provided at the upper middle part of the sliding rack. A motor is installed inside the explosion-proof box. A drive gear that meshes with the tooth groove is coaxially fixed to the output shaft of the motor.

[0009] Preferably, a fixing rod is fixedly connected to one end of the explosion-proof box, and one end of the fixing rod is fixedly connected to the inner wall of the tank. Dovetail grooves are symmetrically opened at both ends of the top surface of the sliding rack, and a dovetail strip that extends into the dovetail groove is fixedly connected to the inner wall of the tank.

[0010] Compared with the prior art, the beneficial effects of this utility model are as follows: This utility model, through the cooperation of a tank body with three spray pipes, extension pipes, and spray heads in different directions, with the spray pipes staggered from top to bottom along the middle of the inner wall of the tank, the extension pipes extending to both sides of the tank body and abutting the inner wall, and the spray heads evenly arranged on the extension pipes, facilitates the coverage of the entire tank body with spray liquid, improving the uniformity of spray coverage, and thus achieving a comprehensive spraying function without blind spots; furthermore, through the cooperation of the motor, drive gear, sliding rack, rotating rod, and guide plate in the adjustment assembly, the motor drives... The driving gear drives the sliding rack to move back and forth. The sliding rack meshes with the reciprocating gear, causing the rotating rod to change the angle of the guide plate. This facilitates the slow flow of ammonia-containing exhaust gas within the tank, increasing the contact time between the exhaust gas and the spray liquid. This allows for sufficient contact between the exhaust gas and the spray liquid. Ultimately, this solves the problem of insufficient spray volume at the tank edge and upper and lower areas due to the use of a single horizontal spray pipe in existing devices, resulting in ammonia-containing exhaust gas being discharged before sufficient contact with the spray liquid. This improves the ammonia absorption efficiency and resource recovery rate, helping the urea process meet environmental emission standards. Attached Figure Description

[0011] The accompanying drawings, which are included to provide a further understanding of the present invention and form part of this application, illustrate exemplary embodiments of the present invention and, together with the description thereof, serve to explain the present invention and do not constitute an undue limitation thereof. In the drawings: Figure 1 This is a first-view schematic diagram of the overall structure proposed in this utility model; Figure 2 This is a first-view schematic diagram of a partial cross-sectional structure of the tank body proposed in this utility model. Figure 3 This is a second-view schematic diagram of a partial cross-sectional structure of the tank body proposed in this utility model; Figure 4 This is a schematic cross-sectional view of the tank body proposed in this utility model.

[0012] The numbers in the diagram are: 1. Tank body; 2. Liquid outlet; 3. Water pipe; 4. Air inlet; 5. Spray pipe; 6. Air outlet; 7. Spray head; 8. Water storage tank; 9. Water inlet; 10. Liquid collection hopper; 11. Liquid outlet pipe; 12. Guide plate; 13. Rotating rod; 14. Sliding rack; 15. Fixed rod. Detailed Implementation

[0013] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0014] Example: See Figures 1 to 4 This utility model discloses a device for reducing ammonia emissions in a urea process, comprising a tank 1, a liquid outlet 2 at the lower end of one side of the tank 1, multiple water pipes 3 on the outer wall of the other side of the tank 1, an air inlet 4 at the lower middle of the outer wall of the tank 1, an air outlet 6 at the middle of the top of the tank 1, three spray pipes 5 arranged sequentially from top to bottom on the middle of the inner wall of the tank 1, a water storage tank 8 at the bottom of the inner wall of the tank 1, and an adjustment component installed inside the tank 1 between the spray pipes 5 and the air inlet 4; the tank 1 is made of Q235 carbon steel. The surface is coated with an epoxy resin anti-corrosion coating, which is resistant to corrosion from ammonia-containing tail gas and absorbent liquid, and the structure is stable. The water supply pipe 3 is made of UPVC material, which is lightweight and anti-aging, and facilitates the transportation of absorbent liquid. The spray pipe 5 is made of 304 stainless steel, which is heat-resistant and does not easily form scale, ensuring smooth spraying. The above components together form the basic framework of the device, providing stable structural support for the introduction of ammonia-containing tail gas, spray absorption, airflow regulation, and waste liquid discharge. Multiple extension pipes are equidistantly arranged on both sides of the spray pipe 5, abutting the inner wall of the tank 1. Multiple extension pipes are equidistantly arranged on the outer wall of one side of the extension pipe. Each spray head 7 has one end of a spray pipe 5 connected to the upper end of multiple water supply pipes 3, and the lower end of the water supply pipes 3 is connected to the interior of a water storage tank 8. A water inlet 9 is located on the inner wall of the water storage tank 8. The extension pipe is made of 304 stainless steel, has good compatibility with the spray pipes 5, and can extend the spray range. The spray heads 7 are 304 stainless steel atomizing spray heads, which can atomize the absorbent liquid into fine droplets, increasing the contact area with the exhaust gas. The water storage tank 8 is made of Q235 carbon steel, with anti-corrosion treatment on the inner wall, and can stably store the absorbent liquid. Based on the above... The system achieves circulating transport and full-area spraying of the absorbent liquid, eliminating blind spots in the spraying process and improving the contact efficiency between ammonia-containing exhaust gas and the spraying liquid. A baffle plate is installed inside tank 1 at the upper end of the air inlet 4. The baffle plate is made of 304 stainless steel, with a smooth and corrosion-resistant surface, effectively preventing spraying liquid droplets from flowing back into the air inlet 4, thus avoiding impact on the operation of the upstream equipment. Simultaneously, it guides the ammonia-containing exhaust gas entering tank 1, directing it towards the spraying area. Through these measures, the stability of the exhaust gas introduction is ensured, reducing the adverse effects of the spraying liquid on the equipment.

[0015] In this invention, a liquid collecting hopper 10 is provided on the inner wall of the tank 1 at the lower end of the air inlet 4, and a liquid outlet pipe 11 is provided between the bottom end of the liquid collecting hopper 10 and the liquid outlet 2. The liquid collecting hopper 10 is made of 304 stainless steel and has a funnel-shaped design to facilitate the centralized collection of the absorbent liquid after spraying. The liquid outlet pipe 11 is made of seamless steel pipe with a pipe diameter adapted to the liquid collecting hopper 10 and the liquid outlet 2 to ensure smooth discharge of the mixed liquid. Through the above, the centralized recovery and efficient discharge of the absorbent liquid are achieved, preventing the absorbent liquid from accumulating at the bottom of the tank 1. The assembly includes multiple rotating rods 13 equidistantly rotatably mounted on the inner wall of the tank 1. A guide plate 12 is fixedly connected to the bottom surface of each rotating rod 13. A reciprocating gear is coaxially fixed to the middle of the rotating rod 13. A sliding rack 14 meshes with the upper end of the reciprocating gear. A tooth groove is formed in the middle of the top surface of the sliding rack 14. An explosion-proof box is located at the upper middle part of the sliding rack 14. A motor is installed inside the explosion-proof box. The output shaft of the motor is coaxially fixedly connected to a drive gear that meshes with the tooth groove. The rotating rods 13 are made of 45# steel, which has high strength and can stably drive the guide plate. Plate 12 rotates; the guide plate 12 is made of 304 stainless steel with a polished surface to reduce airflow resistance; the motor is a three-phase asynchronous motor of model Y2-7124, which provides stable power and can precisely control the reciprocating movement of the sliding rack 14; through the above, the speed and path of the ammonia-containing tail gas flow are flexibly adjusted, extending the contact time between the tail gas and the spray liquid and improving the ammonia absorption effect; a fixing rod 15 is fixedly connected to one end of the explosion-proof box, and one end of the fixing rod 15 is fixedly connected to the inner wall of the tank 1, and the two ends of the top surface of the sliding rack 14 are... Symmetrical dovetail grooves are provided, and dovetail strips extending into the dovetail grooves are fixed to the inner wall of the tank body 1. The explosion-proof box is made of cast aluminum, which has good explosion-proof performance and protects the internal motor for safe operation. The fixing rod 15 is made of 304 stainless steel, which is firmly connected and ensures that the explosion-proof box is fixed in position. The dovetail strips cooperate with the dovetail grooves of the sliding rack 14 to limit the movement direction of the sliding rack 14 and prevent deviation and jamming. Through the above, the stability and safety of the operation of the regulating component are guaranteed, and the airflow regulating function is reliably realized.

[0016] Working Principle: In the use of this utility model, firstly, sufficient absorbent liquid is injected into the water storage tank 8 through the inlet 9 on the inner wall of the tank 1 to complete the liquid preparation before spraying; then, the ammonia-containing tail gas generated in the urea production process is continuously introduced into the tank 1 through the air inlet 4 at the lower end of the middle of the outer wall on one side of the tank 1. After the tail gas enters, it first contacts the baffle plate located at the upper end of the air inlet 4 inside the tank 1. The baffle plate can prevent the splashing droplets during the subsequent spraying process from entering the air inlet 4 downwards, avoiding the droplets from flowing back with the tail gas and affecting the front-end equipment. At the same time, it forms an initial guide for the rising tail gas, guiding it to diffuse towards the middle area of ​​the tank 1, preparing for subsequent contact with the spray liquid; at the same time as the tail gas is introduced, the spraying system is started, because the lower end of the water supply pipe 3 is connected to the inside of the water storage tank 8. The absorbent liquid in the water storage tank 8 is transported through multiple water pipes 3 to three spray pipes 5 arranged sequentially from top to bottom on the inner wall of the tank body 1. Because the spray pipes 5 are staggered, and each spray pipe 5 has multiple extension pipes connected to both sides that abut against the inner wall of the tank body 1, multiple spray heads 7, equidistantly installed on the outer wall of the extension pipes, simultaneously spray the absorbent liquid, forming a multi-layered and all-around spray area without dead angles. Under the action of gravity, the absorbent liquid falls evenly in a mist, forming a counter-current contact with the ammonia-containing tail gas flowing from bottom to top. The ammonia molecules in the tail gas quickly dissolve in the absorbent liquid, completing the initial ammonia absorption process. The incompletely absorbed tail gas continues to flow upward, passing through the three spray areas in sequence, further improving the ammonia absorption efficiency through multiple contacts. To avoid excessively high tail gas flow velocity leading to contact... If insufficient, the adjusting assembly located between the spray pipe 5 and the air inlet 4 is activated. The motor inside the explosion-proof box is powered on and runs. The motor output shaft drives the drive gear to rotate. The drive gear meshes with the tooth groove in the middle of the top surface of the sliding rack 14, driving the sliding rack 14 to move back and forth in the horizontal direction of the tank 1. At the same time, the dovetail grooves at both ends of the top surface of the sliding rack 14 cooperate with the dovetail strips on the inner wall of the tank 1 to ensure smooth sliding. During the movement of the sliding rack 14, it meshes with the reciprocating gears of the multiple rotating rods 13 below, driving the rotating rods 13 to rotate back and forth around the mounting point on the inner wall of the tank 1. This causes the guide plate 12 fixed to the bottom surface of the rotating rod 13 to adjust its tilt angle synchronously. By controlling the forward and reverse rotation frequency of the motor, the tilt degree of the guide plate 12 can be flexibly adjusted to change the flow of exhaust gas in the tank 1. The flow path and velocity are adjusted as follows: when the exhaust gas volume is large, the tilt angle of the guide plate 12 is reduced to slow down the upward speed of the exhaust gas; when the exhaust gas volume is small, the tilt angle is increased to avoid airflow stagnation. This extends the contact time between the exhaust gas and the spray liquid, allowing ammonia molecules more time to dissolve in the absorbent liquid, further enhancing the ammonia absorption effect. The exhaust gas that has completed ammonia absorption continues to flow upward and is finally discharged through the outlet 6 at the top center of the tank 1. The absorbent liquid that has dissolved ammonia after spraying drips downward under the action of gravity. Because the liquid collection hopper 10 at the lower end of the air inlet 4 on the inner wall of the tank 1 is funnel-shaped and covers the entire bottom area of ​​the tank 1, the absorbent liquid will fall into the liquid collection hopper 10. The liquid collection hopper 10 collects the mixed liquid through the liquid outlet pipe 11 at the bottom and transports it to the liquid outlet 2 at the lower end of one side of the tank 1 for discharge.When the absorbent liquid level in the water storage tank 8 drops, it is replenished promptly through the inlet 9 to ensure the continuous and stable operation of the spray system; the device is now in use.

[0017] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A device for reducing ammonia emissions in a urea process, comprising a tank (1), characterized in that: The tank (1) has a liquid outlet (2) at the lower end of one side, and multiple water pipes (3) on the outer wall of the other side of the tank (1). An air inlet (4) is provided at the lower end of the middle of the outer wall of the tank (1). An air outlet (6) is provided at the middle of the top of the tank (1). Three spray pipes (5) in different directions are provided in the middle of the inner wall of the tank (1) from top to bottom. A water storage tank (8) is provided at the bottom of the inner wall of the tank (1). An adjustment component is installed inside the tank (1) between the spray pipes (5) and the air inlet (4).

2. The device for reducing ammonia emissions in a urea process according to claim 1, characterized in that: The spray pipe (5) has multiple extension pipes that abut against the inner wall of the tank (1) at equal intervals on both sides. Multiple spray heads (7) are provided at equal intervals on the outer wall of one side of the extension pipe. One end of the spray pipe (5) is connected to the upper end of multiple water supply pipes (3) one by one. The lower end of the water supply pipe (3) is connected to the inside of the water storage tank (8). A water inlet (9) is opened at one point on the inner wall of the water storage tank (8).

3. The device for reducing ammonia emissions in a urea process according to claim 2, characterized in that: The tank (1) has a baffle plate located at the upper end of the air inlet (4).

4. The device for reducing ammonia emissions in a urea process according to claim 3, characterized in that: The inner wall of the tank (1) is provided with a liquid collection hopper (10) at the lower end of the air inlet (4), and a liquid outlet pipe (11) is provided between the bottom end of the liquid collection hopper (10) and the liquid outlet (2).

5. The device for reducing ammonia emissions in a urea process according to claim 4, characterized in that: The adjustment assembly includes multiple rotating rods (13) equidistantly rotatably arranged on the inner wall of the tank (1). A guide plate (12) is fixed to the bottom surface of the rotating rod (13). A reciprocating gear is coaxially fixed to the middle of the rod body of the rotating rod (13). A sliding rack (14) meshes with the upper end of the reciprocating gear. A tooth groove is opened in the middle of the top surface of the sliding rack (14). An explosion-proof box is provided at the upper end of the middle of the sliding rack (14). A motor is installed in the explosion-proof box. The output shaft of the motor is coaxially fixed to a drive gear that meshes with the tooth groove.

6. The device for reducing ammonia emissions in a urea process according to claim 5, characterized in that: One end of the explosion-proof box is fixedly connected to a fixing rod (15), one end of the fixing rod (15) is fixedly connected to the inner wall of the tank body (1), the top surface of the sliding rack (14) has dovetail grooves symmetrically opened at both ends, and a dovetail strip that extends into the dovetail groove is fixedly connected to the inner wall of the tank body (1).

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