Waste gas secondary reflux absorption tower based on mineral source nitro humic acid production process

Abstract

The invention discloses a waste gas secondary reflux absorption tower based on a mineral source nitro humic acid production process. The waste gas secondary reflux absorption tower comprises an absorption tower, the device comprises a four-way valve, a three-way valve, a balance tank, an intermediate tank, a negative pressure tank and a controller, and the controller is electrically connected with the three-way valve and the four-way valve. Through the arrangement of multiple circulation pipelines, waste gas is circulated for multiple times in the absorption tower, meanwhile, waste gas of the last circulation is stored through the intermediate tank, the device can continuously work, the production cost is reduced, meanwhile, the negative pressure tank is arranged to be safe redundancy, and danger caused by too large pressure is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of waste gas treatment, in particular to a waste gas secondary reflux absorption tower in the production process of mineral source nitrohumic acid. Background Art

[0002] Humic acid is a macromolecular organic substance widely found in nature and widely used in agriculture, forestry, animal husbandry, petroleum, chemical industry, building materials, medicine and health, environmental protection and other fields. Humic acid is a kind of organic substance formed and accumulated by the decomposition and transformation of animal and plant remains by microorganisms and a series of geochemical processes. The humic acid resources that can be developed and utilized at present are some low calorific value coals, such as peat, lignite and weathered coal. Due to the strong oxidizing property of nitric acid, it has a wide range of applicability to dry leaching processes such as non-metallic minerals. However, while nitric acid oxidizes lignite, it is reduced to a variety of gas components, mainly nitric oxide, nitrogen dioxide and other gases. Nitric oxide gas is oxidized to nitrogen dioxide when it encounters air. Nitrogen dioxide gas is yellow in the air, commonly known as yellow smoke, which seriously pollutes the environment. At the same time, because the nitric acid reaction is very violent, it generates a lot of heat, and even boils the liquid, which not only aggravates the generation of yellow smoke, but also makes the gas expand more easily and overflow due to the large amount of heat.

[0003] Patent application No. 202221211735.5 discloses a fluidized dry process system for producing mineral nitrohumic acid and nitrofulvic acid. The system uses a two-stage absorption tower to treat the nitrogen dioxide produced by the reaction, uses a spiral spray layer and a backwash layer to absorb the gas, and promotes the absorption of nitrogen dioxide through a catalytic module, ultimately meeting environmental protection requirements. However, the reflux pipeline of this solution is mainly used for the recycling of nitric acid, but it does not fully utilize the incompletely treated gas. For extremely high concentrations of nitrogen dioxide or other harmful gases, there may still be problems of incomplete treatment. Summary of the invention

[0004] The purpose of the present invention is to solve the problem of complete treatment of gas in an absorption tower and to provide a secondary reflux absorption tower for waste gas in the production process of mineral-based nitrohumic acid.

[0005] A secondary reflux absorption tower for waste gas in the production process of mineral-based nitrohumic acid, comprising:

[0006] Absorption tower; the absorption tower comprises an air inlet A1 at the bottom and an air outlet A2 at the top;

[0007] Four-way valve; the four-way valve includes an outlet B1 connected to the air inlet A1; the four-way valve also includes an air inlet B2, an air inlet B3 and an air inlet B4;

[0008] The air inlet B4 is connected to a first blower;

[0009] Three-way valve; the three-way valve includes an air inlet C1 connected to the air outlet A2; the three-way valve also includes an air outlet C2 connected to the air inlet B2; the three-way valve also includes an air outlet C3;

[0010] A second blower is connected between the air outlet C2 and the air inlet B2;

[0011] The balancing tank includes an air inlet D1 connected to the air outlet C3; the balancing tank also includes an air outlet D2 and an air outlet D3;

[0012] The intermediate tank includes an air inlet E1 connected to the air outlet D3; the intermediate tank also includes an air outlet E2 connected to the air inlet B3; the intermediate tank also includes an air inlet E3;

[0013] Negative pressure tank; the negative pressure tank includes an air inlet F1 connected to the air outlet D2; the negative pressure tank also includes an air outlet F2 connected to the air inlet E3;

[0014] A negative pressure pump is connected between the air outlet F2 and the air inlet E3;

[0015] Controller; the controller is electrically connected to the three-way valve and the four-way valve.

[0016] Further, the air inlet D1 is located at the bottom of the balancing tank; the air outlet D2 is located in the middle of the balancing tank; the air outlet D3 is located at the top of the balancing tank; a limiting groove is provided on the inner wall of the balancing tank; an exhaust fan is slidably provided in the limiting groove; the air outlet D2 is located in the middle of the limiting groove;

[0017] The exhaust fan is provided with fan blades; the outer wall of the exhaust fan is provided with a U-shaped groove; the top of the U-shaped groove is provided with a sealing structure; the U-shaped groove and the air outlet D2 are located in the same vertical plane; the height of the air outlet D2 is located at the top of the U-shaped groove.

[0018] Furthermore, two groups of spray components are arranged in the absorption tower.

[0019] Furthermore, an automatic unloading device is provided at the bottom of the absorption tower.

[0020] Furthermore, a raw material input port is provided at the top of the absorption tower.

[0021] Furthermore, waste liquid collection ports are provided at the bottom of the intermediate tank and the negative pressure tank.

[0022] A waste gas recycling method in the production process of mineral-based nitrohumic acid, comprising:

[0023] Initial reaction cycle

[0024] The first blower blows the exhaust gas in through the air inlet B4, and the controller controls the four-way valve to connect the air inlet B4 and the air outlet B1, and transports the exhaust gas from the air outlet B1 to the air inlet A1, and then the controller closes the four-way valve; the exhaust gas is reacted to by two sets of spray components in the absorption tower and discharged from the air outlet A2, and the controller controls the three-way valve to connect the air inlet C1 and the air outlet C2, and passes the exhaust gas into the second blower and blows it to the air inlet B2, realizing the first circulation of the exhaust gas; the control panel controls the four-way valve to connect the air inlet B2 and the air outlet B1, and passes the exhaust gas into the air inlet A1 to complete the initial circulation, thereby realizing the first reaction treatment of the exhaust gas.

[0025] Secondary reaction cycle

[0026] The waste gas enters the absorption tower for the second time, reacts with the waste gas through two groups of spray components, and is discharged from the outlet A2. The controller controls the three-way valve to connect the air inlet C1 and the air outlet C3 to transport the waste gas to the balance tank; the waste gas enters the balance tank from the air inlet D1, and is output from the air outlet D3 to the air inlet E1, and enters the intermediate tank for sedimentation; when the second batch of waste gas is blown in from the first blower, the controller synchronously connects the air inlet B3 and the air outlet B1 and the air inlet B4 and the air outlet B1, and the waste gas synchronously enters the absorption tower through the air inlet A1 to react, mix the waste gas, and realize multiple cycles of waste gas treatment.

[0027] Safety response cycle

[0028] When the pressure of the exhaust gas entering from the air inlet D1 exceeds the preset safety threshold of the balancing tank, the balancing tank controls the air outlet D2 to open, and guides the exhaust gas from the air inlet D1 to the air outlet D2, and the exhaust gas enters the negative pressure tank from the air outlet D2 through the air inlet F1 to achieve pressure relief; when the pressure is normal, the balancing tank controls the air outlet D2 to close, and starts the negative pressure pump, and passes the exhaust gas in the negative pressure tank from the air outlet F2 through the negative pressure pump and the air inlet E3 into the intermediate tank, thereby achieving a safe reaction cycle and avoiding safety problems of the equipment caused by excessive pressure.

[0029] The beneficial effects of the present invention are:

[0030] Through the setting of multiple circulation pipelines, the exhaust gas can be circulated multiple times in the absorption tower. At the same time, the exhaust gas from the previous cycle is stored in the intermediate tank, so that the device can work continuously and reduce production costs. At the same time, the negative pressure tank is set as safety redundancy to avoid danger caused by excessive pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of the structure of the present invention;

[0032] Figure 2 This is a cross-sectional view of the balancing tank of the present invention;

[0033] Figure 3is a schematic diagram of an exhaust fan;

[0034] In the figure, 1, absorption tower; 11, air inlet A1; 12, air outlet A2; 13, spray assembly; 14, automatic unloading device; 15, raw material input port; 2, four-way valve; 21, air outlet B1; 22, air inlet B2; 23, air inlet B3; 24, air inlet B4; 241, first blower; 3, three-way valve; 31, air inlet C1; 32, air outlet C2; 33, air outlet C3; 4. Balance tank; 41. Air inlet D1; 42. Air outlet D2; 43. Air outlet D3; 44. Limiting groove; 441. Exhaust fan; 442. Fan blade; 45. U-shaped groove; 5. Intermediate tank; 51. Air inlet E1; 52. Air outlet E2; 53. Air inlet E3; 6. Negative pressure tank; 61. Air inlet F1; 62. Air outlet F2; 621. Negative pressure pump; 63. Waste collection port; 7. Controller. DETAILED DESCRIPTION

[0035] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0036] It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention, and thus the drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0037] Example 1

[0038] like Figure 1 to Figure 3 As shown:

[0039] A secondary reflux absorption tower 1 for waste gas in the production process of mineral-based nitrohumic acid, comprising:

[0040] Absorption tower 1; the absorption tower 1 includes an air inlet A111 at the bottom and an air outlet A212 at the top;

[0041] Four-way valve 2; the four-way valve 2 includes an air outlet B121 connected to the air inlet A111; the four-way valve 2 also includes an air inlet B222, an air inlet B323 and an air inlet B424;

[0042] The air inlet B424 is connected to a first blower 241;

[0043] The three-way valve 3 includes an air inlet C131 connected to the air outlet A212; the three-way valve 3 also includes an air outlet C232 connected to the air inlet B222; the three-way valve 3 also includes an air outlet C333;

[0044] A second blower is connected between the air outlet C232 and the air inlet B222;

[0045] The balancing tank 4 includes an air inlet D141 connected to the air outlet C333; the balancing tank 4 also includes an air outlet D242 and an air outlet D343;

[0046] The intermediate tank 5; the intermediate tank 5 includes an air inlet E151 connected to the air outlet D343; the intermediate tank 5 also includes an air outlet E252 connected to the air inlet B323; the intermediate tank 5 also includes an air inlet E353;

[0047] Negative pressure tank 6; the negative pressure tank 6 includes an air inlet F161 connected to the air outlet D242; the negative pressure tank 6 also includes an air outlet F262 connected to the air inlet E353;

[0048] A negative pressure pump 621 is connected between the air outlet F262 and the air inlet E353;

[0049] Controller 7; the controller 7 is electrically connected to the three-way valve 3 and the four-way valve 2.

[0050] The air inlet D141 is located at the bottom of the balancing tank 4; the air outlet D242 is located in the middle of the balancing tank 4; the air outlet D343 is located at the top of the balancing tank 4; a limiting groove 44 is provided on the inner wall of the balancing tank 4; an exhaust fan 441 is slidably provided in the limiting groove 44; the air outlet D242 is located in the middle of the limiting groove 44;

[0051] The exhaust fan 441 is provided with fan blades 442; the outer wall of the exhaust fan 441 is provided with a U-shaped groove 45; the top of the U-shaped groove 45 is provided with a sealing structure; the U-shaped groove 45 and the air outlet D242 are located in the same vertical plane; the air outlet D242 is located at the height of the top of the U-shaped groove 45.

[0052] Through this solution, the exhaust gas flow rate is too high, and the fan blades 442 cannot effectively discharge the exhaust gas, causing the exhaust fan 441 to rise, realizing automatic pressure monitoring, and then the exhaust gas can enter the negative pressure tank 6 through the outlet D242 to achieve pressure relief;

[0053] Two groups of spraying components 13 are arranged in the absorption tower 1. An automatic unloading device 14 is arranged at the bottom of the absorption tower 1. The automatic unloading device 14 is set according to the prior art, and usually blast unloading is performed. At the same time, the unloading in this scheme is usually the product after the reaction; a raw material input port 15 is arranged at the top of the absorption tower 1. The raw material input port 15 is usually used to fill in the reaction raw materials; a waste liquid collection port 63 is arranged at the bottom of the intermediate tank 5 and the negative pressure tank 6. The waste collection port is used to collect the by-products after the reaction.

[0054] Initial reaction cycle

[0055] The first blower blows the exhaust gas in through the air inlet B4, and the controller controls the four-way valve to connect the air inlet B4 and the air outlet B1, and transports the exhaust gas from the air outlet B1 to the air inlet A1, and then the controller closes the four-way valve; the exhaust gas is reacted to by two sets of spray components in the absorption tower and discharged from the air outlet A2, and the controller controls the three-way valve to connect the air inlet C1 and the air outlet C2, and passes the exhaust gas into the second blower and blows it to the air inlet B2, realizing the first circulation of the exhaust gas; the control panel controls the four-way valve to connect the air inlet B2 and the air outlet B1, and passes the exhaust gas into the air inlet A1 to complete the initial circulation, thereby realizing the first reaction treatment of the exhaust gas.

[0056] Through the dual treatment of the initial reaction cycle and the secondary reaction cycle, the waste gas undergoes two spray reactions in the absorption tower 1, which significantly improves the purification efficiency. Combined with the stratified sedimentation of the balance tank 4 and the waste liquid recovery of the intermediate tank 5, the pollutant emissions are further reduced.

[0057] The controller 7 is linked with the three-way and four-way valves 2 to realize automatic switching of the exhaust gas path and adjustment of the circulation mode, reduce manual operation errors, and improve the system response speed and accuracy.

[0058] Secondary reaction cycle

[0059] The waste gas enters the absorption tower for the second time, reacts with the waste gas through two groups of spray components, and is discharged from the outlet A2. The controller controls the three-way valve to connect the air inlet C1 and the air outlet C3 to transport the waste gas to the balance tank; the waste gas enters the balance tank from the air inlet D1, and is output from the air outlet D3 to the air inlet E1, and enters the intermediate tank for sedimentation; when the second batch of waste gas is blown in from the first blower, the controller synchronously connects the air inlet B3 and the air outlet B1 and the air inlet B4 and the air outlet B1, and the waste gas synchronously enters the absorption tower through the air inlet A1 to react, mix the waste gas, and realize multiple cycles of waste gas treatment.

[0060] The waste liquid collection port design at the bottom of the intermediate tank 5 and the negative pressure tank 6 can recover by-products such as nitric acid generated by the reaction, reduce resource waste, realize waste resource utilization, and reduce processing costs.

[0061] Safety response cycle

[0062] When the pressure of the exhaust gas entering from the air inlet D1 exceeds the preset safety threshold of the balancing tank, the balancing tank controls the air outlet D2 to open, and guides the exhaust gas from the air inlet D1 to the air outlet D2, and the exhaust gas enters the negative pressure tank from the air outlet D2 through the air inlet F1 to achieve pressure relief; when the pressure is normal, the balancing tank controls the air outlet D2 to close, and starts the negative pressure pump, and passes the exhaust gas in the negative pressure tank from the air outlet F2 through the negative pressure pump and the air inlet E3 into the intermediate tank, thereby achieving a safe reaction cycle and avoiding safety problems of the equipment caused by excessive pressure.

[0063] When the pressure in the balance tank 4 exceeds a threshold, the U-shaped groove 45 of the exhaust fan 441 is aligned with the gas outlet D242 , and the exhaust gas is decompressed from the middle portion D2 to the negative pressure tank 6 .

[0064] The safety reaction cycle is designed by linking the limit groove 44 and the U-shaped groove 45 of the balance tank 4. When the pressure exceeds the limit, it will automatically release the pressure to the negative pressure tank 6 to avoid the risk of system overload; the negative pressure pump 621 will subsequently recycle the waste gas to ensure no leakage and secondary pollution. This design has high reliability under high pressure or abnormal conditions.

[0065] The above-mentioned embodiments only express the specific implementation of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A secondary reflux absorption tower (1) for waste gas in the production process of mineral-based nitrohumic acid, characterized in that: include An absorption tower (1); the absorption tower (1) comprises an air inlet A1 (11) at the bottom and an air outlet A2 (12) at the top; A four-way valve (2); the four-way valve (2) comprises an air outlet B1 (21) connected to the air inlet A1 (11); the four-way valve (2) further comprises an air inlet B2 (22), an air inlet B3 (23) and an air inlet B4 (24); The air inlet B4 (24) is connected to a first blower (241); A three-way valve (3); the three-way valve (3) comprises an air inlet C1 (31) connected to the air outlet A2 (12); the three-way valve (3) further comprises an air outlet C2 (32) connected to the air inlet B2 (22); the three-way valve (3) further comprises an air outlet C3 (33); A second blower is connected between the air outlet C2 (32) and the air inlet B2 (22); A balance tank (4); the balance tank (4) comprises an air inlet D1 (41) connected to the air outlet C3 (33); the balance tank (4) further comprises an air outlet D2 (42) and an air outlet D3 (43); The intermediate tank (5); the intermediate tank (5) comprises an air inlet E1 (51) connected to the air outlet D3 (43); the intermediate tank (5) further comprises an air outlet E2 (52) connected to the air inlet B3 (23); the intermediate tank (5) further comprises an air inlet E3 (53); A negative pressure tank (6); the negative pressure tank (6) comprises an air inlet F1 (61) connected to the air outlet D2 (42); the negative pressure tank (6) further comprises an air outlet F2 (62) connected to the air inlet E3 (53); A negative pressure pump (621) is connected between the air outlet F2 (62) and the air inlet E3 (53); A controller (7); the controller (7) is electrically connected to the three-way valve (3) and the four-way valve (2).

2. The secondary reflux absorption tower (1) for waste gas in the production process of mineral-based nitrohumic acid according to claim 1, characterized in that: The air inlet D1 (41) is located at the bottom of the balancing tank (4); the air outlet D2 (42) is located in the middle of the balancing tank (4); the air outlet D3 (43) is located at the top of the balancing tank (4); a limiting groove (44) is provided on the inner wall of the balancing tank (4); an exhaust fan (441) is slidably provided in the limiting groove (44); the air outlet D2 (42) is located in the middle of the limiting groove (44); The exhaust fan (441) is provided with fan blades (442); the outer wall of the exhaust fan (441) is provided with a U-shaped groove (45); the top of the U-shaped groove (45) is provided with a sealing structure; the U-shaped groove (45) and the air outlet D2 (42) are located in the same vertical plane; the height of the air outlet D2 (42) is located at the top of the U-shaped groove (45).

3. The secondary reflux absorption tower (1) for waste gas in the production process of mineral-based nitrohumic acid according to claim 1, characterized in that: Two groups of spray components (13) are arranged in the absorption tower (1).

4. The secondary reflux absorption tower (1) for waste gas in the production process of mineral-based nitrohumic acid according to claim 1, characterized in that: An automatic unloading device (14) is provided at the bottom of the absorption tower (1).

5. The secondary reflux absorption tower (1) for waste gas in the production process of mineral-based nitrohumic acid according to claim 1, characterized in that: The top of the absorption tower (1) is provided with a raw material input port (15).

6. The secondary reflux absorption tower (1) for waste gas in the production process of mineral-based nitrohumic acid according to claim 1, characterized in that: The bottoms of the intermediate tank (5) and the negative pressure tank (6) are both provided with waste liquid collection ports (63).

7. A method for treating waste gas in the production process of mineral-based nitrohumic acid, characterized in that: include Initial reaction cycle The first blower blows the exhaust gas in through the air inlet B4, and the controller controls the four-way valve to connect the air inlet B4 and the air outlet B1, and transports the exhaust gas from the air outlet B1 to the air inlet A1, and then the controller closes the four-way valve; the exhaust gas is reacted to by two sets of spray components in the absorption tower and discharged from the air outlet A2, and the controller controls the three-way valve to connect the air inlet C1 and the air outlet C2, and passes the exhaust gas into the second blower and blows it to the air inlet B2, realizing the first circulation of the exhaust gas; the control panel controls the four-way valve to connect the air inlet B2 and the air outlet B1, and passes the exhaust gas into the air inlet A1 to complete the initial circulation, thereby realizing the first reaction treatment of the exhaust gas. Secondary reaction cycle The waste gas enters the absorption tower for the second time, reacts with the waste gas through two groups of spray components, and is discharged from the outlet A2. The controller controls the three-way valve to connect the air inlet C1 and the air outlet C3 to transport the waste gas to the balance tank; the waste gas enters the balance tank from the air inlet D1, and is output from the air outlet D3 to the air inlet E1, and enters the intermediate tank for sedimentation; when the second batch of waste gas is blown in from the first blower, the controller synchronously connects the air inlet B3 and the air outlet B1 and the air inlet B4 and the air outlet B1, and the waste gas synchronously enters the absorption tower through the air inlet A1 to react, mix the waste gas, and realize multiple cycles of waste gas treatment. Safety response cycle When the pressure of the exhaust gas entering from the air inlet D1 exceeds the preset safety threshold of the balancing tank, the balancing tank controls the air outlet D2 to open, and guides the exhaust gas from the air inlet D1 to the air outlet D2, and the exhaust gas enters the negative pressure tank from the air outlet D2 through the air inlet F1 to achieve pressure relief; when the pressure is normal, the balancing tank controls the air outlet D2 to close, and starts the negative pressure pump, and passes the exhaust gas in the negative pressure tank from the air outlet F2 through the negative pressure pump and the air inlet E3 into the intermediate tank, thereby achieving a safe reaction cycle and avoiding safety problems of the equipment caused by excessive pressure.

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