Water-gas exchange device and method for purifying industrial waste gas using the water-gas exchange device

Abstract

The invention discloses a water-gas exchange device and a method for purifying industrial waste gas using the water-gas exchange device. The water-gas exchange device comprises a plurality of water-gas exchange components. The method for purifying industrial waste gas using the water-gas exchange device connects three water-gas exchange components in series, wherein a saturated lime water solution is added to the first water-gas exchange component to remove sulfur dioxide gas in the waste gas; a 1:1 alkaline potassium persulfate solution is added to the second water-gas exchange component to remove nitrogen oxides in the waste gas; a 20% ethanolamine water solution is added to the third water-gas exchange component to remove carbon dioxide in the waste gas; compared with the current spray tower waste gas purification technology, the invention will significantly improve the contact probability and reaction efficiency of the waste gas and the reaction liquid, and at the same time, the space required for the pipeline reaction device is much smaller than that of the spray tower, which can effectively reduce equipment costs and safety risks, and plays an important role in improving the purification efficiency of industrial waste gas.

Description

Technical Field

[0001] The present invention belongs to the technical field of waste gas treatment, and in particular relates to a water-gas exchange device and a method for purifying industrial waste gas using the water-gas exchange device. Background Art

[0002] Industrial waste gas such as coal smoke from thermal power plants contains a large amount of gases such as carbon dioxide, carbon monoxide, sulfur dioxide, nitric oxide and nitrogen dioxide. Among them, sulfur dioxide, nitric oxide and nitrous oxide are the main gases that form acid rain. How to effectively remove sulfur dioxide, nitric oxide and nitrous oxide in coal smoke exhaust gas is an important task in preventing and controlling air pollution.

[0003] At present, sulfur dioxide, nitrogen monoxide and nitrous oxide in industrial waste gas are mostly removed by spray tower technology. The spray tower generally includes a box, a circulating liquid, a packing layer, an atomization layer, a spray layer and other parts. The working principle is to draw the waste gas into the tower through a fan, and then use a water pump to atomize the reaction liquid into a small liquid in the spray tower through a spray head and contact the waste gas. The reaction liquid removes harmful substances in the waste gas by adsorption, dissolution and chemical reaction. The treated waste gas is discharged at the top of the tower to achieve the purpose of purification. Because the gas-liquid mass transfer method of the spray tower is liquid mass transfer in the gas, it is necessary to atomize the reaction liquid as much as possible, and provide enough space for the gas and the atomized droplets to fully contact and react. Therefore, the spray tower is generally large in size and high in height, which leads to the disadvantages of high cost, difficult construction, and great safety hazards. At the same time, the volume of the tower body is limited after all, and it is difficult for the atomized liquid to fully contact and react with the waste gas, resulting in the removal effect of the waste gas being affected by many parameters and conditions of the spray tower, and it is difficult to accurately control. Summary of the invention

[0004] The present invention provides a water-gas exchange device and a method for purifying industrial waste gas using the water-gas exchange device. The present invention pumps waste gas into a reaction liquid for full mixing, and then performs gas-liquid mass transfer in reactors with different pipe diameters. Compared with the current spray tower waste gas purification technology, the present invention will significantly improve the contact probability and reaction efficiency of waste gas and reaction liquid. At the same time, the space required for the pipeline reaction device is much smaller than that of the spray tower, which can effectively reduce equipment costs and safety risks, and plays an important role in improving the purification efficiency of industrial waste gas.

[0005] To solve the above problems, the technical solution provided by the present invention is as follows:

[0006] An embodiment of the present invention provides a water-gas exchange device, comprising a plurality of groups of water-gas exchange components, each group of water-gas exchange components comprising a liquid tank (1), a water-gas mixing tube (2), a plurality of small reaction tubes (3), a plurality of large reaction tubes (4), a plurality of adapters (5), a gas-liquid separation tube (6), an exhaust port (7), a liquid inlet (8), a liquid discharge port (9), a fan (10), a first water pump (11) and a second water pump (12);

[0007] The liquid tank (1) is connected to the water-gas mixing tube (2) via a first water pump (11); the plurality of side-by-side small reaction tubes (3) are connected to the plurality of side-by-side large reaction tubes (4) via the adapter (5); one of the side-by-side small reaction tubes (3) at the left end is connected to the water-gas mixing tube (2) via a second water pump (12); one of the side-by-side large reaction tubes (4) at the right end is connected to the gas-liquid separation tube (2) via a small reaction tube (3); The gas-liquid separation tube (6) is connected to the liquid tank (1), the bottom of the gas-liquid separation tube (6) is connected to the liquid tank (1), the top of the gas-liquid separation tube (6) is connected to the exhaust port (7), the bottom of the gas-liquid separation tube (6) is connected to the liquid inlet (8), and the bottom of the liquid tank (1) is connected to the liquid discharge port (9); the water-gas mixing tube (2) between the first water pump (11) and the second water pump (12) is also connected to the air outlet of the fan (10), and the air inlet of the fan (10) is connected to the exhaust gas;

[0008] The exhaust port (7) of the first group of water-gas exchange components in two adjacent groups of water-gas exchange components is connected to the air inlet of the fan (10) of the next group of water-gas exchange components.

[0009] According to an optional embodiment of the present invention, the liquid tank (1) is a rectangular cavity made of polyethylene (PE) or fiber-reinforced plastic (FRP); the water-gas mixing pipe (2) is a water pipe made of polyethylene (PE) with four air vents on its upper portion, one end of the air vent being connected to the air outlet of the fan (10).

[0010] According to an optional embodiment of the present invention, the first water pump (11) is a siphon pump, the second water pump (12) is a gas-liquid mixing pump, and the flow rate of the first water pump (11) is 2 / 3 of the flow rate of the second water pump (12).

[0011] According to an optional embodiment of the present invention, the small reaction tube (3) and the large reaction tube (4) are both water pipes made of polyethylene (PE), and the diameter of the large reaction tube (4) is twice the diameter of the small reaction tube (3).

[0012] According to an optional embodiment of the present invention, the adapter (5) is a curved pipe made of polyethylene (PE), the inner diameter of one end of the adapter (5) is the outer diameter of the small reaction tube (3), and the inner diameter of the other end is the inner diameter of the large reaction tube (4); wherein the four small reaction tubes (3) and the four large reaction tubes (4) are connected front to back through eight adapters (5), and are connected in series to form an overall structure for repeated water-gas exchange.

[0013] According to an optional embodiment of the present invention, the gas-liquid separation tube (6) is a tank body made of polyethylene (PE), the diameter of the gas-liquid separation tube (6) is 1.5 times the diameter of the large reaction tube (4), the top of the gas-liquid separation tube (6) is a semi-spherical structure, and the length of the small reaction tube (3) inserted into the gas-liquid separation tube (6) is 1 / 3 of the actual height of the gas-liquid separation tube (6).

[0014] According to an optional embodiment of the present invention, the exhaust port (7), the liquid inlet (8) and the liquid discharge port (9) are all water pipes made of polyethylene (PE), and an air valve made of polyethylene (PE) is installed on the exhaust port (7); and a water valve made of polyethylene (PE) is installed on the liquid inlet (8) and the liquid discharge port (9).

[0015] The embodiment of the present invention further provides a method for purifying industrial waste gas using a water-gas exchange device, which is implemented by a water-gas exchange device as in the above embodiment, and includes the following steps:

[0016] Step S1, selecting three groups of water-gas exchange components, connecting the exhaust port (7) of the previous group of water-gas exchange components with the air inlet of the fan (10) of the next group of water-gas exchange components to form a set of serially connected gas processing channels;

[0017] Step S2, respectively closing the valves of the liquid discharge ports (9) in the three groups of water-gas exchange components, and respectively opening the valves of the air discharge ports (7) and the valves of the liquid inlet ports (8) in the three groups of water-gas exchange components;

[0018] Step S3, filling the liquid tank (1) with a saturated lime water solution through the liquid inlet (8) of the first group of water gas exchange components; filling the liquid tank (1) with a 1:1 alkaline potassium persulfate solution through the liquid inlet (8) of the second group of water gas exchange components, wherein the molar ratio of sodium hydroxide to potassium persulfate in the alkaline potassium persulfate solution is 1:1; and filling the liquid tank (1) with an MEA absorbent through the liquid inlet (8) of the third group of water gas exchange components, wherein the MEA absorbent includes a 20% ethanolamine aqueous solution;

[0019] Step S4, respectively starting the first water pump (11) and the second water pump (12) in the three groups of water-gas exchange components, so that the three liquids form circulation flows in the three groups of water-gas exchange components respectively;

[0020] Step S5, connecting the dust-removed industrial waste gas to the fan (10) in the first group of water-gas exchange components through a PE pipe, and starting the fan (10) in the first group of water-gas exchange components to pump the industrial waste gas into the first group of water-gas exchange components to achieve the desulfurization treatment target;

[0021] Step S6, turning on the fan (10) in the second group of water-gas exchange components, pumping the industrial tail gas treated by the first group of water-gas exchange components into the second group of water-gas exchange components, to achieve the denitration treatment target;

[0022] Step S7, turning on the fan (10) in the third group of water-gas exchange components, pumping the industrial tail gas treated by the second group of water-gas exchange components into the third group of water-gas exchange components, so as to achieve the goal of reducing carbon dioxide treatment;

[0023] Step S8, detect the exhaust concentration after being treated by the three groups of water-gas exchange components. If it meets the national emission standards, it will be discharged through the chimney; if it does not meet the emission standards, it will be re-pumped into the first group of water-gas exchange components by an air pump for circulation purification treatment until it meets the national emission standards and is discharged through the chimney.

[0024] Beneficial effects: The embodiment of the present invention provides a water-gas exchange device and a method for purifying industrial waste gas using the water-gas exchange device, the water-gas exchange device includes multiple groups of water-gas exchange components, each group of water-gas exchange components includes a liquid tank, a water-gas mixing tube, multiple small reaction tubes, multiple large reaction tubes, multiple adapters, a gas-liquid separation tube, an exhaust port, a liquid inlet, a liquid outlet, a fan, a first water pump and a second water pump; the method for purifying industrial waste gas using the water-gas exchange device is to connect three groups of water-gas exchange components in series, wherein a saturated lime water solution is added to the first group of water-gas exchange components to remove sulfur dioxide gas in the waste gas; a 1:1 alkaline potassium persulfate solution is added to the second group of water-gas exchange components to remove nitrogen oxides in the waste gas; a 20% ethanolamine aqueous solution is added to the third group of water-gas exchange components to remove carbon dioxide in the waste gas; compared with the current spray tower waste gas purification technology, the present invention will significantly improve the contact probability and reaction efficiency of the waste gas and the reaction liquid, and at the same time, the space required for the pipeline reaction device is much smaller than the spray tower, which can effectively reduce equipment costs and safety risks, and plays an important role in improving the purification efficiency of industrial waste gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0026] Figure 1 A schematic diagram of the structure of a group of water-gas exchange components in a water-gas exchange device provided in an embodiment of the present application.

[0027] Figure 2 A schematic diagram of the structure of a water-gas exchange device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0029] like Figure 1 and Figure 2 As shown, an embodiment of the present invention provides a water-gas exchange device, including multiple groups of water-gas exchange components, each group of water-gas exchange components includes a liquid tank 1, a water-gas mixing tube 2, a plurality of small reaction tubes 3, a plurality of large reaction tubes 4, a plurality of adapters 5, a gas-liquid separation tube 6, an exhaust port 7, a liquid inlet 8, a liquid outlet 9, a fan 10, a first water pump 11 and a second water pump 12.

[0030] The liquid tank 1 is connected to the water-gas mixing tube 2 through a first water pump 11, a plurality of side-by-side small reaction tubes 3 are connected to a plurality of side-by-side large reaction tubes 4 through an adapter 5, a small reaction tube 3 at the left end of the plurality of side-by-side small reaction tubes 3 is connected to the water-gas mixing tube 2 through a second water pump 12; a large reaction tube 4 at the right end of the plurality of side-by-side large reaction tubes 4 is connected to a gas-liquid separation tube 6 through a small reaction tube 3, the bottom of the gas-liquid separation tube 6 is connected to the liquid tank 1, the top of the gas-liquid separation tube 6 is connected to the exhaust port 7, the bottom of the gas-liquid separation tube 6 is connected to the liquid inlet 8, and the bottom of the liquid tank 1 is connected to the liquid discharge port 9; the pipeline between the first water pump 11 and the second water pump 12 is also connected to the air outlet of the fan 10, and the exhaust gas is introduced into the air inlet of the fan 10.

[0031] The exhaust port 7 of the first group of water-gas exchange components in two adjacent groups of water-gas exchange components is connected to the air inlet of the fan 10 of the next group of water-gas exchange components.

[0032] The liquid tank 1 is a rectangular cavity made of polyethylene PE or fiber reinforced plastic FRP; the water-gas mixing pipe 2 is a water pipe made of polyethylene PE, with four vents on the upper part, one end of which is connected to the air outlet of the fan 10.

[0033] The first water pump 11 is a siphon pump, the second water pump 12 is a gas-liquid mixing pump, and the flow rate of the first water pump 11 is 2 / 3 of the flow rate of the second water pump 12 .

[0034] The small reaction tube 3 and the large reaction tube 4 are both water pipes made of polyethylene PE, and the diameter of the large reaction tube 4 is twice the diameter of the small reaction tube 3 .

[0035] The adapter 5 is a curved pipe made of polyethylene PE. The inner diameter of one end of the adapter 5 is the outer diameter of the small reaction tube 3, and the inner diameter of the other end is the inner diameter of the large reaction tube 4. In this embodiment, the four small reaction tubes 3 and the four large reaction tubes 4 are connected front and back through eight adapters 5, and are connected in series to form an overall structure for repeated water and gas exchange. Figure 1 .

[0036] The gas-liquid separation tube 6 is a tank body made of polyethylene PE. The diameter of the gas-liquid separation tube 6 is 1.5 times the diameter of the large reaction tube 4. The top of the gas-liquid separation tube 6 is a semi-spherical structure. The last small reaction tube 3 on the left penetrates into the gas-liquid separation tube 6 by a length of 1 / 3 of the actual height of the gas-liquid separation tube 6.

[0037] The exhaust port 7, the liquid inlet 8 and the liquid discharge port 9 are all water pipes made of polyethylene PE, and an air valve made of polyethylene PE is installed on the exhaust port 7. The liquid inlet 8 and the liquid discharge port 9 are both equipped with water valves made of polyethylene PE.

[0038] The embodiment of the present invention further provides a method for purifying industrial waste gas using a water-gas exchange device, which is implemented by a water-gas exchange device as in the above embodiment, and includes the following steps:

[0039] Step S1, such as Figure 2 As shown, three groups of water-gas exchange components are selected, and the exhaust port 7 of the previous group of water-gas exchange components is connected to the air inlet of the fan 10 of the next group of water-gas exchange components to form a set of serially connected gas processing channels;

[0040] Step S2, respectively closing the valves of the liquid discharge ports 9 in the three groups of water-gas exchange components, and respectively opening the valves of the air discharge ports 7 and the valves of the liquid inlet ports 8 in the three groups of water-gas exchange components;

[0041] Step S3, filling the liquid tank 1 with a saturated lime water solution through the liquid inlet 8 of the first group of water gas exchange components; filling the liquid tank 1 with a 1:1 alkaline potassium persulfate solution through the liquid inlet 8 of the second group of water gas exchange components, wherein the molar ratio of sodium hydroxide to potassium persulfate in the alkaline potassium persulfate solution is 1:1; filling the liquid tank 1 with an MEA absorbent through the liquid inlet 8 of the third group of water gas exchange components, wherein the MEA absorbent includes a 20% ethanolamine aqueous solution;

[0042] Step S4, respectively starting the first water pump 11 and the second water pump 12 in the three groups of water-gas exchange components, so that the three liquids form circulation flows in the three groups of water-gas exchange components respectively;

[0043] Step S5, connecting the dust-removed industrial waste gas to the fan 10 in the first water-gas exchange assembly through a PE pipe, and starting the fan 10 of the first water-gas exchange assembly to pump the industrial waste gas into the first water-gas exchange assembly to achieve the desulfurization treatment target;

[0044] Step S6, turning on the fan 10 in the second group of water-gas exchange components, pumping the industrial tail gas treated by the first group of water-gas exchange components into the second group of water-gas exchange components, to achieve the denitration treatment target;

[0045] Step S7, turning on the fan 10 in the third group of water-gas exchange components, pumping the industrial tail gas treated by the second group of water-gas exchange components into the third group of water-gas exchange components, to achieve the goal of reducing carbon dioxide treatment;

[0046] Step S8, detect the exhaust concentration after being treated by the three groups of water-gas exchange components. If it meets the national emission standards, it will be discharged through the chimney; if it does not meet the emission standards, it will be re-pumped into the first group of water-gas exchange components by an air pump for circulation purification treatment until it meets the national emission standards and is discharged through the chimney.

[0047] In this embodiment, the liquid tank 1 of the first group of water-gas exchange components is filled with saturated lime water, the liquid tank 2 of the second group of water-gas exchange components is filled with 1:1 alkaline potassium persulfate solution, and the liquid tank 2 of the third group of water-gas exchange components is filled with MEA absorbent; the industrial tail gas that has been subjected to dust removal treatment is injected into the air inlet of the fan of the first group of water-gas exchange components, and is treated by the first group of water-gas exchange components to achieve desulfurization and removal of sulfur dioxide, and is treated by the second group of water-gas exchange components to achieve denitrification and removal of gaseous nitrogen oxides, and is treated by the third group of water-gas exchange components to achieve carbon reduction and reduction of carbon dioxide concentration. The qualified gas discharged from the exhaust port 7 of the third group of water-gas exchange components is discharged through the factory chimney.

[0048] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited to them. Any modifications, equivalent substitutions and improvements made by any technician familiar with the technical field within the technical scope disclosed by the present invention and within the spirit and principle of the present invention should be covered within the protection scope of the present invention. Ordinary technicians in this field can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be based on the scope defined by the claims.

Claims

1. A water-gas exchange device, characterized in that: It comprises a plurality of water-gas exchange components, each of which comprises a liquid tank (1), a water-gas mixing tube (2), a plurality of small reaction tubes (3), a plurality of large reaction tubes (4), a plurality of adapters (5), a gas-liquid separation tube (6), an exhaust port (7), a liquid inlet (8), a liquid outlet (9), a fan (10), a first water pump (11) and a second water pump (12); The liquid tank (1) is connected to the water-gas mixing tube (2) via a first water pump (11); the plurality of side-by-side small reaction tubes (3) are connected to the plurality of side-by-side large reaction tubes (4) via the adapter (5); one of the side-by-side small reaction tubes (3) at the left end is connected to the water-gas mixing tube (2) via a second water pump (12); one of the side-by-side large reaction tubes (4) at the right end is connected to the gas-liquid separation tube (2) via a small reaction tube (3); The gas-liquid separation tube (6) is connected to the liquid tank (1), the bottom of the gas-liquid separation tube (6) is connected to the liquid tank (1), the top of the gas-liquid separation tube (6) is connected to the exhaust port (7), the bottom of the gas-liquid separation tube (6) is connected to the liquid inlet (8), and the bottom of the liquid tank (1) is connected to the liquid discharge port (9); the water-gas mixing tube (2) between the first water pump (11) and the second water pump (12) is also connected to the air outlet of the fan (10), and the air inlet of the fan (10) is connected to the exhaust gas; The adapter (5) is a curved pipe made of polyethylene (PE), the inner diameter of one end of the adapter (5) is the outer diameter of the small reaction tube (3), and the inner diameter of the other end is the inner diameter of the large reaction tube (4); wherein the four small reaction tubes (3) and the four large reaction tubes (4) are connected front to back through the eight adapters (5), and are connected in series to form an overall structure for repeated water-gas exchange; The exhaust port (7) of the first group of water-gas exchange components in two adjacent groups of water-gas exchange components is connected to the air inlet of the fan (10) of the next group of water-gas exchange components.

2. A water-gas exchange device according to claim 1, characterized in that: The liquid tank (1) is a rectangular cavity made of polyethylene (PE) or fiber reinforced plastic (FRP); the water-gas mixing pipe (2) is a water pipe made of polyethylene (PE) with four ventilation holes on its upper part, one end of the ventilation hole is connected to the air outlet of the fan (10).

3. A water-gas exchange device according to claim 2, characterized in that: The first water pump (11) is a siphon pump, the second water pump (12) is a gas-liquid mixing pump, and the flow rate of the first water pump (11) is 2 / 3 of the flow rate of the second water pump (12).

4. A water-gas exchange device according to claim 3, characterized in that: The small reaction tube (3) and the large reaction tube (4) are both water pipes made of polyethylene (PE), and the diameter of the large reaction tube (4) is twice the diameter of the small reaction tube (3).

5. A water-gas exchange device according to claim 4, characterized in that: The gas-liquid separation tube (6) is a tank body made of polyethylene (PE). The diameter of the gas-liquid separation tube (6) is 1.5 times the diameter of the large reaction tube (4). The top of the gas-liquid separation tube (6) is a semi-spherical structure. The length of the small reaction tube (3) inserted into the gas-liquid separation tube (6) is 1 / 3 of the actual height of the gas-liquid separation tube (6).

6. A water-gas exchange device according to claim 5, characterized in that: The exhaust port (7), the liquid inlet (8) and the liquid discharge port (9) are all water pipes made of polyethylene (PE); an air valve made of polyethylene (PE) is installed on the exhaust port (7); and a water valve made of polyethylene (PE) is installed on the liquid inlet (8) and the liquid discharge port (9).

7. A method for purifying industrial waste gas using a water-gas exchange device, which is achieved by using a water-gas exchange device as claimed in any one of claims 1 to 6, characterized in that: The steps include: Step S1, selecting three groups of water-gas exchange components, connecting the exhaust port (7) of the previous group of water-gas exchange components with the air inlet of the fan (10) of the next group of water-gas exchange components to form a set of serially connected gas processing channels; Step S2, respectively closing the valves of the liquid discharge ports (9) in the three groups of water-gas exchange components, and respectively opening the valves of the air discharge ports (7) and the valves of the liquid inlet ports (8) in the three groups of water-gas exchange components; Step S3, filling the liquid tank (1) with a saturated lime water solution through the liquid inlet (8) of the first group of water-gas exchange components; filling the liquid tank (1) with a 1:1 alkaline potassium persulfate solution through the liquid inlet (8) of the second group of water-gas exchange components, wherein the molar ratio of sodium hydroxide to potassium persulfate in the alkaline potassium persulfate solution is 1:1; Filling the liquid tank (1) with an MEA absorbent through a liquid inlet (8) of the third group of water-gas exchange components, wherein the MEA absorbent comprises a 20% ethanolamine aqueous solution; Step S4, respectively starting the first water pump (11) and the second water pump (12) in the three groups of water-gas exchange components, so that the three liquids form circulation flows in the three groups of water-gas exchange components respectively; Step S5, connecting the dust-removed industrial waste gas to the fan (10) in the first group of water-gas exchange components through a PE pipe, and starting the fan (10) in the first group of water-gas exchange components to pump the industrial waste gas into the first group of water-gas exchange components to achieve the desulfurization treatment target; Step S6, turning on the fan (10) in the second group of water-gas exchange components, pumping the industrial tail gas treated by the first group of water-gas exchange components into the second group of water-gas exchange components, to achieve the denitration treatment target; Step S7, turning on the fan (10) in the third group of water-gas exchange components, pumping the industrial tail gas treated by the second group of water-gas exchange components into the third group of water-gas exchange components, so as to achieve the goal of reducing carbon dioxide treatment; Step S8, detect the exhaust concentration after being treated by the three groups of water-gas exchange components. If it meets the national emission standards, it will be discharged through the chimney; if it does not meet the emission standards, it will be re-pumped into the first group of water-gas exchange components by an air pump for circulation purification treatment until it meets the national emission standards and is discharged through the chimney.

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