An ammonia recovery and treatment device

Abstract

This utility model relates to the field of industrial waste gas treatment technology, specifically to an ammonia recovery and treatment device, including a primary absorption tank and an aerator. The aerator's outlet is connected to a first outlet pipe and a second outlet pipe. The second outlet pipe extends into the primary absorption tank, and one end of the second outlet pipe inside the primary absorption tank is connected to two downward-curved pipes, both of which extend near the bottom of the primary absorption tank. A transfer gas supply pipe is connected to the top of the primary absorption tank. This utility model uses the aerator to transport ammonia to the absorption system via a dual path. The second outlet pipe, in conjunction with the downward-curved pipes, guides the ammonia to the bottom of the primary absorption tank, increasing the dissolution path by utilizing the liquid depth. The transfer gas supply pipe guides unabsorbed ammonia to the bottom of the secondary absorption tank, forming a two-stage series absorption structure. The first outlet pipe can directly send ammonia to the secondary absorption tank for absorption when the absorbent in the primary absorption tank is replaced, thus achieving uninterrupted ammonia recovery.

Description

Technical Field

[0001] This utility model relates to the field of industrial waste gas treatment technology, specifically to an ammonia recovery and treatment device. Background Technology

[0002] Ammonia is widely used as an important chemical raw material or intermediate product in many industrial fields such as chemical production, fertilizer manufacturing, pharmaceuticals, and electronics. For example, in fertilizer production, ammonia is a key raw material for synthesizing nitrogen fertilizers such as urea and ammonium nitrate; in the pharmaceutical industry, ammonia is often used in organic synthesis reactions; and in the electronics industry, ammonia is used in the cleaning and etching processes during semiconductor chip manufacturing.

[0003] Existing technology, such as patent application number CN202022560977.2, discloses a waste ammonia gas recovery device, which includes a waste ammonia gas recovery tank, a coil, a bottom support for the coil, and a top fixing device for the coil. The coil is installed inside the waste ammonia gas recovery tank, and its wall has multiple through holes. Waste ammonia gas enters the water dispersedly through the through holes in the coil wall, making full contact with the water and being almost entirely absorbed, with very few waste ammonia gas bubbles escaping from the water surface. The bottom support and top fixing device secure the coil to prevent it from moving within the waste ammonia gas recovery tank. However, in actual use, when the absorbent reaches saturation, the equipment needs to be stopped for absorbent replacement, causing an interruption in the ammonia gas treatment process and preventing continuous and stable waste gas treatment, which seriously affects production efficiency. Furthermore, during absorbent replacement, unabsorbed ammonia gas may escape into the air, causing secondary pollution.

[0004] In view of this, we propose an ammonia recovery and treatment device. Utility Model Content

[0005] To overcome the above shortcomings, this utility model provides an ammonia recovery and treatment device.

[0006] The technical solution of this utility model is:

[0007] An ammonia recovery and treatment device includes a primary absorption tank and an aerator. The aerator's outlet is connected to a first outlet pipe and a second outlet pipe. The second outlet pipe extends into the interior of the primary absorption tank. One end of the second outlet pipe inside the primary absorption tank is connected to two downward-curved pipes, both of which extend near the bottom of the primary absorption tank. The top of the primary absorption tank is connected to a transfer gas pipe. The end of the transfer gas pipe away from the primary absorption tank is connected to a secondary absorption tank. The first outlet pipe is connected to the transfer gas pipe, which extends into the secondary absorption tank near its bottom. A tail gas pipe is installed on the top of the secondary absorption tank, and the tail gas pipe connects to the interior of a spray tower. Ammonia gas is delivered to the absorption system via an aerator through a dual-path system. The second outlet pipe, in conjunction with the lower bend pipe, guides the ammonia gas to the bottom of the primary absorption tank, increasing the dissolution path by utilizing the liquid depth. The transfer pipe guides unabsorbed ammonia gas to the bottom of the secondary absorption tank, forming a two-stage series absorption structure. The first outlet pipe can directly send ammonia gas to the secondary absorption tank for absorption when the absorbent in the primary absorption tank is replaced, thus achieving uninterrupted ammonia gas recovery. The tail gas pipe connects to a spray tower for further purification of the tail gas, achieving tertiary treatment.

[0008] As a preferred technical solution, a first porous exhaust plate is installed at the bottom of each of the lower bends, and a second porous exhaust plate is installed at the bottom of the intermediate gas transfer pipe. The porous exhaust plates at the bottom of the lower bends and the end of the intermediate gas transfer pipe disperse the ammonia gas into tiny bubbles, ensuring thorough mixing of the ammonia gas with the absorbent liquid.

[0009] As a preferred technical solution, a stirring mechanism is installed inside the primary absorption tank. The stirring mechanism includes a stirring shaft rotatably mounted inside the primary absorption tank, with several stirring blades fixedly installed on the outer circumference of the stirring shaft. A stirring motor with an output shaft coaxially fixed to the stirring shaft is installed on the outer wall of the primary absorption tank. Dynamic mixing breaks down the diffusion resistance of the liquid film, allowing ammonia molecules to contact the absorbent more quickly; simultaneously, it prevents dissolution equilibrium shifts caused by excessively high local concentrations.

[0010] As a preferred technical solution, the stirring shaft and the second air outlet pipe are offset left and right, and the stirring blade and the lower curved pipe are offset front and back, with one of the lower curved pipes passing over the stirring shaft. The left-right offset of the stirring shaft and the second air outlet pipe, and the front-back offset of the stirring blade and the lower curved pipe, avoid interference between mechanical parts.

[0011] As a preferred technical solution, several partitions are fixedly installed inside the secondary absorption box, dividing the interior of the secondary absorption box into an S-shaped flow channel, through which the transfer gas pipe passes. The partitions inside the secondary absorption box form an S-shaped flow channel, forcing ammonia gas to cross the liquid layer multiple times in a tortuous path, thus prolonging the residence time.

[0012] As a preferred technical solution, a spray plate is installed at the top of the spray tower, and the exhaust pipe connects to the middle of the interior of the spray tower. An initial liquid level is set at the bottom of the spray tower, which is higher than the drain outlet. The spray plate at the top of the spray tower forms a uniform water mist layer, and the exhaust pipe guides the pretreated gas into the middle of the spray zone, ensuring full contact between the rising airflow and the falling droplets. The initial liquid level being higher than the drain outlet forms a liquid seal, preventing short-circuit emission of untreated gas.

[0013] As a preferred technical solution, a booster pump is installed on the exhaust pipe, and a check valve is installed on the transfer gas pipe, with the check valve installed upstream of the first outlet pipe. The booster pump increases the gas pressure inside the exhaust pipe, forcing the gas to accelerate through the spray zone, thereby increasing the relative velocity of the gas and liquid and the mass transfer driving force; the check valve installed upstream of the first outlet pipe prevents the absorbent liquid from flowing back to the aerator.

[0014] As a preferred technical solution, the first and second vent pipes are not used simultaneously. The first vent pipe is only activated when the absorbent in the absorption tank is replaced, so as to achieve uninterrupted recovery of ammonia.

[0015] Compared with the prior art, the beneficial effects of this utility model are:

[0016] This invention uses an aerator to deliver ammonia to the absorption system via a dual-pathway system. The second outlet pipe, in conjunction with the lower bend pipe, guides the ammonia to the bottom of the primary absorption tank, increasing the dissolution path by utilizing the liquid depth. The intermediate gas transfer pipe guides the unabsorbed ammonia to the bottom of the secondary absorption tank, forming a two-stage series absorption structure. The first outlet pipe can directly send ammonia to the secondary absorption tank for absorption when the absorbent in the primary absorption tank is replaced, thus achieving uninterrupted recovery of ammonia. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0018] Figure 2 This is a schematic diagram of the internal structure of the primary absorption box in this utility model;

[0019] Figure 3 This is a schematic diagram of the internal structure of the secondary absorption box in this utility model;

[0020] Figure 4 This is a schematic diagram of the spray tower in this utility model;

[0021] The meanings of the labels in the diagram are as follows:

[0022] 1. Primary absorption tank; 10. Transfer gas pipe; 100. Second perforated exhaust plate; 101. Check valve; 11. Stirring motor; 12. Stirring shaft; 13. Stirring blades; 2. Aerator; 20. First exhaust pipe; 21. Second exhaust pipe; 22. Lower bend pipe; 23. First perforated exhaust plate; 3. Secondary absorption tank; 30. Baffle plate; 4. Tail gas pipe; 40. Booster pump; 5. Spray tower; 50. Spray plate. Detailed Implementation

[0023] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0024] Please refer to the accompanying drawings. This utility model provides a technical solution:

[0025] like Figures 1-4 As shown, an ammonia recovery and treatment device includes a primary absorption tank 1 and an aerator 2. The outlet of the aerator 2 is connected to a first outlet pipe 20 and a second outlet pipe 21. The second outlet pipe 21 extends into the primary absorption tank 1. One end of the second outlet pipe 21 inside the primary absorption tank 1 is connected to two downward bend pipes 22. Both downward bend pipes 22 extend to near the bottom of the primary absorption tank 1. The top of the primary absorption tank 1 is connected to a transfer gas pipe 10. The end of the transfer gas pipe 10 away from the primary absorption tank 1 is connected to a secondary absorption tank 3. The first outlet pipe 20 is connected to the transfer gas pipe 10. The transfer gas pipe 10 extends into the secondary absorption tank 3 near the bottom. A tail gas pipe 4 is installed on the top of the secondary absorption tank 3. The tail gas pipe 4 is connected to the interior of a spray tower 5. Ammonia gas is transported to the absorption system via a dual-pathway aerator 2. The second outlet pipe 21, in conjunction with the lower bend pipe 22, guides the ammonia gas to the bottom of the primary absorption tank 1, increasing the dissolution path by utilizing the liquid depth. The transfer pipe 10 guides the unabsorbed ammonia gas to the bottom of the secondary absorption tank 3, forming a two-stage series absorption structure. The first outlet pipe 20 can directly send ammonia gas to the secondary absorption tank 3 for absorption when the absorbent in the primary absorption tank 1 is replaced, thus achieving uninterrupted recovery of ammonia gas. The tail gas pipe 4 connects to the spray tower 5 to further purify the tail gas, achieving tertiary treatment.

[0026] like Figure 2 and Figure 3As shown, as a preferred technical solution, a first porous exhaust plate 23 is installed at the bottom of each lower bend pipe 22, and a second porous exhaust plate 100 is installed at the bottom of the intermediate gas transmission pipe 10. The porous exhaust plates at the bottom of the lower bend pipe 22 and the end of the intermediate gas transmission pipe 10 disperse the ammonia gas into tiny bubbles, ensuring thorough mixing of the ammonia gas with the absorbent liquid.

[0027] like Figure 2 As shown, as a preferred technical solution, a stirring mechanism is installed inside the primary absorption tank 1. The stirring mechanism includes a stirring shaft 12 rotatably installed inside the primary absorption tank 1, and several stirring blades 13 are fixedly installed on the outer circumference of the stirring shaft 12. A stirring motor 11 with an output shaft coaxially fixed to the stirring shaft 12 is installed on the outer wall of the primary absorption tank 1. Dynamic mixing breaks down the diffusion resistance of the liquid film, allowing ammonia molecules to contact the absorbent more quickly; at the same time, it prevents the dissolution equilibrium from shifting due to excessively high local concentrations.

[0028] like Figure 2 As shown, in a preferred embodiment, the stirring shaft 12 and the second air outlet pipe 21 are offset left and right, and the stirring blade 13 and the lower curved pipe 22 are offset front and back, with one of the lower curved pipes 22 passing over the stirring shaft 12. The left and right offset of the stirring shaft 12 and the second air outlet pipe 21, and the front and back offset of the stirring blade 13 and the lower curved pipe 22, avoid interference between mechanical parts.

[0029] like Figure 3 As shown, as a preferred technical solution, several baffles 30 are fixedly installed inside the secondary absorption box 3. The baffles 30 divide the secondary absorption box 3 into an S-shaped flow channel, through which the transfer gas pipe 10 passes. The baffles 30 inside the secondary absorption box 3 form an S-shaped flow channel, forcing the ammonia gas to cross the liquid layer multiple times in a tortuous path, thus prolonging the residence time.

[0030] like Figure 4 As shown, in a preferred embodiment, a spray plate 50 is installed on the top of the spray tower 5, and the exhaust pipe 4 connects to the middle of the interior of the spray tower 5. An initial liquid level is provided at the bottom of the spray tower 5, which is higher than the drain outlet of the spray tower 5. The spray plate 50 at the top of the spray tower 5 forms a uniform water mist layer, and the exhaust pipe 4 guides the pretreated gas into the middle of the spray zone, ensuring full contact between the rising airflow and the falling droplets. The initial liquid level being higher than the drain outlet forms a liquid seal, preventing short-circuit discharge of untreated gas.

[0031] like Figure 1 As shown, as a preferred technical solution, a booster pump 40 is installed on the exhaust pipe 4, and a check valve 101 is installed on the transfer gas pipe 10. The check valve 101 is installed upstream of the first outlet pipe 20. The booster pump 40 increases the gas pressure in the exhaust pipe 4, forcing the gas to accelerate through the spray zone, thereby increasing the relative velocity of the gas and liquid and the mass transfer driving force; the check valve 101 is installed upstream of the first outlet pipe 20 to prevent the absorbent liquid from flowing back to the aerator 2.

[0032] As a preferred technical solution, the first outlet pipe 20 and the second outlet pipe 21 are not used simultaneously. The first outlet pipe 20 is only activated when the absorbent in the primary absorption tank 1 is replaced, so as to achieve uninterrupted ammonia recovery. It should be noted that the absorbent in the secondary absorption tank 3 can be replaced immediately after the absorbent in the primary absorption tank 1 is replaced.

[0033] like Figure 1 As shown, it should be added that a valve is installed on both the first vent pipe 20 and the second vent pipe 21, and the two valves on the first vent pipe 20 and the second vent pipe 21 are not opened at the same time.

[0034] like Figure 1 As shown, it should also be noted that both absorption tanks are equipped with inlet pipes for adding absorbent liquid at the top, and each inlet pipe is equipped with a valve. Both absorption tanks also have a first drain pipe installed near the bottom on their outer walls, and each first drain pipe is equipped with a valve.

[0035] like Figure 1 As shown, it should also be noted that a spray pipe connected to the spray plate 50 is installed at the top of the spray tower 5, and a second drain pipe is installed on the outer wall of the spray tower 5 near the bottom. Valves are installed on both the spray pipe and the drain pipe.

[0036] like Figure 1 As shown, it should also be noted that the bottom of the primary absorption tank 1, the secondary absorption tank 3, and the spray tower 5 are all equipped with several support legs.

[0037] In the initial state of use, the valve of the second outlet pipe 21 of this utility model is open, the valve of the first outlet pipe 20 is closed, and the aerator 2 is started. The ammonia gas is dispersed into microbubbles through the second outlet pipe 21 and the first porous exhaust plate 23 at the bottom of the lower bend pipe 22. It comes into contact with the absorbent liquid in the primary absorption tank 1 and dissolves. The stirring mechanism in the primary absorption tank 1 operates synchronously to accelerate the dissolution process. The undissolved ammonia gas enters the secondary absorption tank 3 through the transfer gas pipe 10 and is dispersed again through the second porous exhaust plate 100. It rises in the S-shaped channel in the tank to achieve deep absorption. The residual ammonia gas enters the spray tower 5 through the tail gas pipe 4 and comes into counter-current contact with the mist droplets sprayed by the spray plate 50 under the action of the pressurization pump 40 to complete the three-stage purification. When the absorbent in the primary absorption tank 1 is nearly saturated, close the valve of the second outlet pipe 21 and open the valve of the first outlet pipe 20 to directly guide the ammonia gas to the secondary absorption tank 3. Simultaneously, empty the primary absorption tank 1 and inject fresh absorbent. After the primary absorption tank 1 is replaced, switch back to the second outlet pipe 21 for gas supply and perform maintenance on the secondary absorption tank 3. During this process, the check valve 101 prevents backflow of the absorbent, and the liquid seal of the spray tower 5 prevents short-circuit discharge of untreated gas. Both absorption tanks and the spray tower 5 are equipped with inlet and outlet pipes for easy addition and replacement of the absorbent. The support legs at the bottom of the device ensure stable operation. This device achieves efficient and uninterrupted ammonia recovery and product resource utilization through multi-stage absorption, dynamic pipeline switching, and anti-backflow design.

[0038] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. An ammonia recovery and treatment device, characterized in that: The aerator (2) includes a primary absorption box (1) and an aerator (2). The aerator (2) has a first air outlet pipe (20) and a second air outlet pipe (21) connected to its outlet. The second air outlet pipe (21) extends into the primary absorption box (1). One end of the second air outlet pipe (21) inside the primary absorption box (1) is connected to two downward bend pipes (22). Both downward bend pipes (22) extend to the bottom of the primary absorption box (1). The top of the primary absorption box (1) is connected to a transfer air supply pipe (10). The end of the transfer air supply pipe (10) away from the primary absorption box (1) is connected to a secondary absorption box (3). The first air outlet pipe (20) is connected to the transfer air supply pipe (10). The transfer air supply pipe (10) extends into the secondary absorption box (3) near the bottom. A tail gas pipe (4) is installed on the top of the secondary absorption box (3). The tail gas pipe (4) is connected to the inside of the spray tower (5).

2. The ammonia recovery and treatment device as described in claim 1, characterized in that: Each of the lower bends (22) is equipped with a first perforated exhaust plate (23) at the bottom, and the intermediate gas transfer pipe (10) is equipped with a second perforated exhaust plate (100) at the bottom.

3. The ammonia recovery and treatment device as described in claim 2, characterized in that: A stirring mechanism is installed inside the primary absorption tank (1). The stirring mechanism includes a stirring shaft (12) that is rotatably installed inside the primary absorption tank (1). Several stirring blades (13) are fixedly installed on the outer circumference of the stirring shaft (12). A stirring motor (11) with an output shaft coaxially fixed to the stirring shaft (12) is installed on the outer wall of the primary absorption tank (1).

4. The ammonia recovery and treatment device as described in claim 3, characterized in that: The stirring shaft (12) and the second air outlet pipe (21) are offset to the left and right, and the stirring blade (13) and the lower bend pipe (22) are offset to the front and back, and one of the lower bend pipes (22) passes over the stirring shaft (12).

5. The ammonia recovery and treatment device as described in claim 4, characterized in that: The secondary absorption box (3) is fixedly installed with several partitions (30). The partitions (30) divide the secondary absorption box (3) into an S-shaped flow channel, and the transfer gas pipe (10) passes through the partitions (30).

6. The ammonia recovery and treatment device as described in claim 5, characterized in that: The spray tower (5) is equipped with a spray plate (50) on top, and the tail gas pipe (4) is connected to the middle of the interior of the spray tower (5). The bottom of the spray tower (5) is provided with an initial liquid level, which is higher than the drain outlet of the spray tower (5).

7. The ammonia recovery and treatment device as described in claim 6, characterized in that: A booster pump (40) is installed on the exhaust pipe (4), and a check valve (101) is installed on the transfer gas pipe (10). The check valve (101) is installed upstream of the first exhaust pipe (20).

8. The ammonia recovery and treatment device as described in claim 7, characterized in that: The first vent pipe (20) and the second vent pipe (21) are not used at the same time.

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