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

Abstract

The utility model 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] This utility model relates to the field of waste gas treatment technology, and in particular to a secondary reflux absorption tower for waste gas in the production process of mineral-derived nitrohumic acid. Background Technology

[0002] Humic acid is a large-molecule organic substance widely found in nature, with extensive applications in agriculture, forestry, animal husbandry, petroleum, chemical industry, building materials, medicine and health, environmental protection, and other fields. Humic acid is a class of organic substances formed and accumulated from the decomposition and transformation of plant and animal remains by microorganisms and through a series of geochemical processes. Currently, the humic acid resources that can be developed and utilized are some low-calorific-value coals, such as peat, lignite, and weathered coal. While nitric acid's strong oxidizing properties make it widely applicable to dry leaching processes for non-metallic minerals, nitric acid itself is reduced to various gaseous components, primarily nitric oxide and nitrogen dioxide, while oxidizing lignite. Nitric oxide is further oxidized to nitrogen dioxide upon contact with air. Nitrogen dioxide is yellow in air, commonly known as "yellow smoke," which severely pollutes the environment. Furthermore, the highly vigorous reaction of nitric acid generates a large amount of heat, even causing liquids to boil, which not only exacerbates the production of yellow smoke but also causes the gas to expand and escape more easily.

[0003] Patent application number 202221211735.5 discloses a fluidized dry process system for producing mineral-derived nitrohumic acid and nitrofulvic acid. This system treats nitrogen dioxide generated during the reaction using a two-stage absorption tower, absorbs the gas using a spiral spray layer and a backwash layer, and promotes nitrogen dioxide absorption through a catalytic module, ultimately meeting environmental protection requirements. However, the reflux pipeline in this scheme is mainly used for the recovery and reuse of nitric acid, but it does not fully utilize the incompletely treated gas. For extremely high concentrations of nitrogen dioxide or other harmful gases, incomplete treatment may still exist. Utility Model Content

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

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

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

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

[0008] A first blower is connected to the air inlet B4;

[0009] The three-way valve comprises an air inlet C1 connected with the air outlet A2; the three-way valve further comprises an air outlet C2 connected with the air inlet B2; the three-way valve further comprises an air outlet C3;

[0010] The second air blower is arranged between the air outlet C2 and the air inlet B2.

[0011] The balance tank comprises an air inlet D1 connected with the air outlet C3; the balance tank further comprises an air outlet D2 and an air outlet D3.

[0012] The intermediate tank comprises an air inlet E1 connected with the air outlet D3; the intermediate tank further comprises an air outlet E2 connected with the air inlet B3; the intermediate tank further comprises an air inlet E3.

[0013] The negative pressure tank comprises an air inlet F1 connected with the air outlet D2; the negative pressure tank further comprises an air outlet F2 connected with the air inlet E3.

[0014] The negative pressure pump is arranged between the air outlet F2 and the air inlet E3.

[0015] The controller is electrically connected with the three-way valve and the four-way valve.

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

[0017] The exhaust fan is provided with a fan blade; 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] Further, the absorption tower is provided with two groups of spraying assemblies.

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

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

[0021] Further, the bottom of the intermediate tank and the negative pressure tank is provided with a waste liquid collecting port.

[0022] A waste gas recycling method based on a production process of mineral source nitro humic acid, comprising

[0023] Initial reaction cycle

[0024] The first air blower blows the waste gas into the air inlet B4, the controller controls the four-way valve to connect the air inlet B4 and the air outlet B1, the waste gas is transported from the air outlet B1 to the air inlet A1, and then the controller closes the four-way valve; the waste gas is reacted by the two groups of spray assemblies in the absorption tower and discharged from the air outlet A2, the controller controls the three-way valve to connect the air inlet C1 and the air outlet C2, the waste gas is blown into the second air blower and sent to the air inlet B2, and the first circulation of the waste gas is realized; the control panel controls the four-way valve to connect the air inlet B2 and the air outlet B1, the waste gas is sent to the air inlet A1 to complete the initial circulation, and the first reaction treatment of the waste gas is realized.

[0025] Secondary reaction cycle

[0026] The waste gas is reacted by the two groups of spray assemblies in the absorption tower and discharged from the air outlet A2, the controller controls the three-way valve to connect the air inlet C1 and the air outlet C3, and the waste gas is transported 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 to settle; when the second batch of waste gas is blown from the first air blower, the controller synchronously connects the air inlet B3 and the air outlet B1 and the air inlet B4 and the air outlet B1, the waste gas is synchronously introduced into the absorption tower through the air inlet A1 to react, the waste gas is mixed, and multiple circulation and reciprocal treatment of the waste gas are realized.

[0027] Safe reaction cycle

[0028] When the pressure of the waste gas entering from the air inlet D1 exceeds the preset safety threshold of the balance tank, the balance tank controls the air outlet D2 to be opened, the waste gas is introduced from the air inlet D1 to the air outlet D2, and the waste gas is introduced from the air outlet D2 into the negative pressure tank through the air inlet F1 to realize pressure relief; when the pressure is normal, the balance tank controls the air outlet D2 to be closed, and the negative pressure pump is started, the waste gas in the negative pressure tank is introduced into the intermediate tank from the air outlet F2 through the negative pressure pump through the air inlet E3, and the safe reaction cycle is realized, so that the safety problem of the equipment caused by excessive pressure is avoided.

[0029] The beneficial effects of the utility model are:

[0030] Through the multiple circulation pipeline setting, the waste gas is circulated in the absorption tower for multiple times, and the waste gas of the last circulation is stored in the intermediate tank, so that the device can continuously work, the production cost is reduced, and the negative pressure tank is set as a safety redundancy to avoid danger caused by excessive pressure. DRAWINGS

[0031] Fig. 1 It is a structural schematic view of the utility model;

[0032] Fig. 2 It is a sectional view of the balance tank of the utility model;

[0033] Fig. 3 Figure shows a schematic diagram of an exhaust fan;

[0034] In the figure, 1, absorption tower; 11, air inlet A1; 12, air outlet A2; 13, spraying 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 air 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 embodiments of the present application will be described in detail with specific examples. Those skilled in the art can easily understand other advantages and functions of the present application from the content disclosed in the specification. The present application can also be implemented or applied in other different embodiments, and various modifications or changes can be made to the details in the specification without departing from the spirit of the present application. It should be noted that the following examples and features in the examples can be combined with each other without conflict.

[0036] It should be noted that the diagrams provided in the following examples only illustrate the basic concept of the present application in a schematic manner, and only the components related to the present application are shown in the diagrams, not the number, shape and size of the components when actually implemented. The actual implementation of each component may be arbitrarily changed in shape, number and proportion, and the layout pattern of the components may also be more complex.

[0037] Example 1

[0038] As shown in the following: Figs. 1-3

[0039] A secondary reflux absorption tower 1 for waste gas in the production process of mineral source nitro humic acid, comprising

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

[0041] A four-way valve 2; the four-way valve 2 comprises an air outlet B121 communicated with the air inlet A111; the four-way valve 2 further comprises an air inlet B222, an air inlet B323 and an air inlet B424; ​

[0042] A first air blower 241 is arranged on the air inlet B424;

[0043] A three-way valve 3, which comprises an air inlet C131 connected with the air outlet A212, an air outlet C232 connected with the air inlet B222, and an air outlet C333;

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

[0045] A balance tank 4, which comprises an air inlet D141 connected with the air outlet C333, an air outlet D242, and an air outlet D343;

[0046] An intermediate tank 5, which comprises an air inlet E151 connected with the air outlet D343, an air outlet E252 connected with the air inlet B323, and an air inlet E353;

[0047] A negative pressure tank 6, which comprises an air inlet F161 connected with the air outlet D242, and an air outlet F262 connected with the air inlet E353;

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

[0049] A controller 7, which is electrically connected with the three-way valve 3 and the four-way valve 2.

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

[0051] A fan blade 442 is arranged in the exhaust fan 441, a U-shaped groove 45 is arranged on the outer wall of the exhaust fan 441, the top of the U-shaped groove 45 is arranged as a sealed structure, the U-shaped groove 45 and the air outlet D242 are located in the same vertical plane, and the height of the air outlet D242 is located at the top of the U-shaped groove 45.

[0052] Through the scheme, when the exhaust gas flow rate is too large and the fan blade 442 cannot effectively exhaust the exhaust gas, the exhaust fan 441 is lifted to realize automatic pressure monitoring, and then the exhaust gas can enter the negative pressure tank 6 through the air outlet D242 to realize pressure relief;

[0053] The absorption tower 1 is provided with two groups of spray assemblies 13. The bottom of the absorption tower 1 is provided with an automatic unloading device 14. The automatic unloading device 14 is provided as prior art, and generally air blowing unloading, while in the present scheme, the unloading is generally the product after reaction; the top of the absorption tower 1 is provided with a raw material input port 15. The raw material input port 15 is generally used to fill the reaction raw materials; the bottom of the intermediate tank 5 and the negative pressure tank 6 is provided with a waste liquid collecting port 63. The waste liquid collecting port is used to collect the by-products after reaction.

[0054] Initial reaction cycle

[0055] The first air blower blows the waste gas through the air inlet B4, the controller controls the four-way valve to connect the air inlet B4 and the air outlet B1, and the waste gas is transported from the air outlet B1 to the air inlet A1, and then the controller closes the four-way valve; the waste gas is reacted in the absorption tower by two groups of spray assemblies and discharged from the air outlet A2, the controller controls the three-way valve to connect the air inlet C1 and the air outlet C2, and the waste gas is blown into the second air blower and sent to the air inlet B2, realizing the first cycle of the waste gas; the control panel controls the four-way valve to connect the air inlet B2 and the air outlet B1, and the waste gas is introduced into the air inlet A1 to complete the initial cycle, realizing the first reaction treatment of the waste gas.

[0056] Through the double treatment of the initial reaction cycle and the secondary reaction cycle, the waste gas experiences two spray reactions in the absorption tower 1, significantly improving the purification efficiency. Combined with the layered settlement of the balance tank 4 and the waste liquid recovery of the intermediate tank 5, the pollutant emission is further reduced.

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

[0058] Secondary reaction cycle

[0059] The second time the waste gas enters the absorption tower is reacted by two groups of spray assemblies and discharged from the air outlet A2, the controller controls the three-way valve to connect the air inlet C1 and the air outlet C3, and the waste gas is transported 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 settlement; when the second batch of waste gas is blown from the first air 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 enters the absorption tower through the air inlet A1 for reaction, mixing the waste gas, realizing multiple cycle processing of the waste gas.

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

[0061] Safe reaction cycle

[0062] When the exhaust gas pressure from the inlet D1 exceeds the preset safety threshold of the balance tank, the balance tank controls the outlet D2 to open, and the exhaust gas from the inlet D1 is introduced into the outlet D2, and the exhaust gas from the outlet D2 enters the negative pressure tank through the inlet F1 to realize pressure relief; when the pressure is normal, the balance tank controls the outlet D2 to close, and starts the negative pressure pump to introduce the exhaust gas in the negative pressure tank from the outlet F2 into the intermediate tank through the inlet E3, realizes the safe reaction cycle, and avoids the safety problem of the equipment caused by excessive pressure.

[0063] When the pressure in the balance tank 4 exceeds the threshold, the U-shaped groove 45 of the exhaust fan 441 is aligned with the outlet D2 42, and the exhaust gas is discharged from the middle D2 to the negative pressure tank 6.

[0064] The safety reaction cycle is linked with the U-shaped groove 45 through the limiting groove 44 of the balance tank 4, and when the pressure is over-limit, it is automatically discharged to the negative pressure tank 6, avoiding the risk of system overload; the negative pressure pump 621 subsequently recovers the exhaust gas, ensuring no leakage and secondary pollution. This design has high reliability under high pressure or abnormal working conditions

[0065] The above-described embodiments only express the specific implementation of the present application, and the description is more specific and detailed, but it cannot be understood as a limitation on the scope of the present application. It should be pointed out that for ordinary skilled persons in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which all belong to the protection scope of the present application.

Claims

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

2. A secondary reflux absorption tower (1) for waste gas in the production process of mineral-based nitro humic acid according to claim 1, characterized in that: The air inlet D1 (41) is located at the bottom of the balance tank (4), the air outlet D2 (42) is located in the middle of the balance tank (4), the air outlet D3 (43) is located at the top of the balance tank (4), the inner wall of the balance tank (4) is provided with a limiting groove (44), an exhaust fan (441) is slidably arranged in the limiting groove (44), and the air outlet D2 (42) is located in the middle of the limiting groove (44). The exhaust fan (441) is provided with a fan blade (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, and the height of the air outlet D2 (42) is located at the top of the U-shaped groove (45).

3. A secondary reflux absorption tower (1) for waste gas in the production process of mineral-based nitro humic acid according to claim 1, characterized in that: The absorption tower (1) is provided with two groups of spraying assemblies (13).

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

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

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