A device and method for desulfurization by adding a gas guiding coil to reinforce liquid column tower

Abstract

The application provides a device and method for desulfurization of liquid column tower with air guide coil, which comprises an absorption tower body and a reverse spray tower connected with the absorption tower body at the lower end, the upper part of the reverse spray tower is provided with a tail gas inlet and is connected with a fan; the top of the absorption tower body is provided with a tail gas outlet, and the bottom is used for storing absorption liquid; a liquid distributor and a liquid column spraying device are installed below the tail gas inlet in the reverse spray tower; an air guide coil is arranged at the lower end of the reverse spray tower, the air guide coil comprises an air guide disc and a plurality of air guide pipes communicated with the air guide disc, and the air guide pipes are immersed in the absorption liquid at the bottom of the absorption tower body; after the sulfur-containing tail gas enters the tower and is reacted and absorbed by the liquid column sprayed by the liquid column spraying device, the tail gas is introduced into the absorption liquid in the absorption tower body from the air guide pipe under the pressure of the fan, and secondary reaction and absorption are carried out to achieve better absorption effect, and the method has the advantages of high desulfurization efficiency, good desulfurization effect, low mist content in outlet gas and the like.

Description

Technical Field

[0001] This invention belongs to the field of flue gas desulfurization technology, specifically, it relates to a device and method for enhancing liquid column tower desulfurization by adding a gas guide coil. Background Technology

[0002] SO2 is a gaseous pollutant with a large quantity and wide impact among atmospheric pollutants, and it is one of the major air pollutants facing humanity today. The sources of atmospheric SO2 fall into two main categories: natural sources and anthropogenic sources. Due to the atmosphere's self-purification capacity, naturally occurring SO2 generally does not cause serious air pollution; however, anthropogenic emissions account for a large amount of SO2, representing two-thirds of the total atmospheric SO2, and are the main cause of air pollution and acid rain. If not effectively treated, it will exacerbate soil and water acidification, disrupt ecological balance, and affect biodiversity.

[0003] CN202983508U discloses a multi-stage, multi-scale injection device for a liquid column tower. Its technological feature is that different types and heights of injection nozzles are set in the absorption tower, and multiple layers of densely packed droplets with progressively increasing particle size are formed in the tower space. Although this technology improves desulfurization efficiency, the flue gas absorbed by this technology has a high mist content at the outlet, which increases the load on the subsequent demister and has little positive effect on energy saving and consumption reduction.

[0004] CN109621681A discloses a Venturi desulfurization device, including a main tower body, an inlet pipe, a first spray device, a Venturi device, a second spray device, a desulfurization pump, and an outlet pipe. The main tower body is internally constructed into a left tower chamber and a right tower chamber separated by space. The right tower chamber is internally divided from top to bottom into an atomization chamber, a reaction chamber, and a purification chamber connected in sequence. The purification chamber is connected to the left tower chamber via a connecting pipe. The inlet pipe passes through the left tower chamber and connects to the top of the right tower chamber. The first spray device is located in the atomization chamber. The Venturi device is located in the reaction chamber. The second spray device is located in the reaction chamber and passes through the Venturi device. The desulfurization pump is located outside the right tower chamber and is connected to both the first and second spray devices. The outlet pipe is connected to the interior of the left tower chamber. This invention's Venturi desulfurization device can effectively increase the liquid-to-gas ratio and reduce the amount of absorbent used, but its desulfurization efficiency is not significantly improved, and the exhaust gas after absorption still does not meet industrial emission requirements. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a device and method for enhancing liquid column desulfurization in a reverse-flow tower by adding a gas guide coil. By sequentially installing a liquid column injector and a gas guide coil inside the reverse-flow tower, the flue gas entering the tower is first absorbed by the liquid column reaction, and then aerated in the absorbent liquid at the bottom of the absorption tower body through the gas guide coil for secondary reaction absorption. Furthermore, a porous throttling plate accelerates the gas flow to the optimal demisting speed range, achieving a good demisting effect.

[0006] This invention is achieved through the following technical solution:

[0007] A device for enhancing liquid column tower desulfurization by adding a gas guide coil, the device comprising an absorber tower body and a reverse spray tower whose lower end communicates with the side wall of the absorber tower body, wherein:

[0008] The upper part of the reverse spray tower is provided with an exhaust gas inlet, which is connected to a fan for blowing in the exhaust gas; the top of the absorption tower body is provided with an exhaust gas outlet, and the bottom of the absorption tower body is used to store the absorption liquid.

[0009] Inside the reverse spray tower, a liquid distributor and a liquid jet injection device with its lower end connected and fixed to the liquid distributor are installed below the exhaust gas inlet. The liquid jet injection device includes several liquid jet injectors. The liquid inlet of the liquid distributor is connected to the bottom of the absorption tower body through a circulation pipeline. The liquid distributor is used to transport the absorbent stored at the bottom of the absorption tower body to the liquid distributor for distribution and then spray it into the reverse spray tower through the liquid jet injection device to react and absorb the exhaust gas. A water pump is installed on the circulation pipeline.

[0010] The lower end of the reverse spray tower is provided with a gas guide coil. The gas guide coil includes a gas guide plate and several gas guide pipes connected to the gas guide plate. The gas guide plate is fixedly connected to the inner wall of the reverse spray tower around its perimeter. The gas guide pipes are immersed in the absorbent liquid at the bottom of the main body of the absorption tower and are used to pass the gas absorbed by the liquid column reaction into the absorbent liquid at the bottom of the main body of the absorption tower for aeration and secondary enhanced reaction absorption.

[0011] The present invention is further configured such that the air guide plate is vertically connected to the inner wall of the reverse spray tower, and the air guide pipe is immersed in the lower part of the absorbent liquid at the bottom of the main body of the absorption tower.

[0012] The present invention is further configured such that the gas guide coil is made of PVC material, and the number and diameter of the gas guide pipes are adjusted according to the flue gas treatment capacity of the liquid column tower, wherein the diameter of the gas guide pipes is set to 1-5cm, and the number is adjusted according to the size of the gas guide coil.

[0013] The present invention is further configured such that, inside the main body of the absorption tower, above the connection between the main body of the absorption tower and the backspray tower, a throttling orifice plate and a demister are sequentially arranged, which are used to accelerate the gas after aeration reaction to the optimal demisting speed range through the throttling orifice plate, and then discharge it from the exhaust gas outlet after being demisted by the demister.

[0014] The present invention is further configured such that the throttling orifice plate is made of polypropylene, the thickness of the orifice plate is 3-5cm, and the opening diameter is 0.1-1.5mm, which can be adjusted according to the different demisters used.

[0015] The present invention is further configured such that a liquid inlet is provided on the side wall of the absorption tower body for introducing the absorbent liquid required by the enhanced liquid column tower desulfurization device into the bottom of the absorption tower body; the liquid inlet is connected to a liquid inlet valve for controlling the feeding of absorbent liquid into the absorption tower body.

[0016] The invention is further configured such that, along the water flow direction, the circulation pipeline is sequentially equipped with a main tower outlet valve and an ejector inlet valve; depending on actual operating requirements, one or more of the main tower outlet valve and ejector inlet valve are configured; a liquid flow meter is installed on the circulation pipeline, and a first pressure gauge and a second pressure gauge are sequentially installed along the water flow direction to monitor the flow rate and pressure on the circulation pipeline; a drain pipeline is connected to the circulation pipeline, and a drain outlet valve is installed on the drain pipeline to control the discharge of absorbent liquid from the main body of the absorption tower.

[0017] The present invention is further configured such that the drain line is located between the main tower outlet valve and the ejector inlet valve on the circulation line, and is located between the first pressure gauge and the second pressure gauge, so that the first pressure gauge and the second pressure gauge are used to monitor the pressure of the outlet section and the circulation section of the circulation line, respectively.

[0018] The invention is further configured such that a spraying device is provided at the top of the reverse spray tower for spraying small droplets to react with the exhaust gas just entering the reverse spray tower; the spraying device is connected to an external spray liquid pipeline, or to a spray liquid pipeline connected to the bottom of the absorption tower body. Preferably, the spray liquid pipeline is connected to the circulation pipeline, utilizing the absorbent liquid inside the absorption tower body for spraying at the top of the reverse spray tower, and a spraying device valve is provided on the spray liquid pipeline for controlling the feed of the spray liquid.

[0019] The present invention also provides a method for enhancing flue gas desulfurization using the device with added air guide coil to enhance liquid column tower desulfurization, the specific steps of which are as follows:

[0020] Sulfur dioxide-containing exhaust gas enters the reverse spray tower through the exhaust gas inlet via the blower, reacting and being absorbed by the liquid column sprayed by the liquid column injection device. The reacted gas, under the pressure of the blower, is introduced from the lower air guide coil of the reverse spray tower into the absorbent liquid inside the absorption tower body for aeration, undergoing secondary reaction absorption. At the same time, the absorbent liquid in the reverse spray tower circulates back into the absorption tower body through the air guide coil. The gas after aeration and reaction is discharged from the exhaust gas outlet.

[0021] The invention is further configured such that the spraying device generates a large number of tiny droplets with a diameter of 30-120μm, and the exhaust gas entering the reverse spray tower first reacts with the tiny droplets sprayed by the spraying device at the top of the reverse spray tower for preliminary absorption.

[0022] The present invention is further configured such that, in order to ensure that the absorbent liquid smoothly enters the liquid column ejector and is ejected to generate a liquid column of sufficient height, a certain pressure needs to be provided by the water pump. Specifically, the water pressure of the water pump needs to reach 0.35 MPa and the head needs to be set to more than 35 m.

[0023] The present invention is further configured such that the gas after aeration reaction is accelerated by the orifice plate and flows through the demister to achieve the best demisting effect; the demisted gas is discharged from the exhaust outlet.

[0024] The present invention is further configured such that the gas flow rate after aeration by the air guide coil is 0.5-1.0 m / s, and the gas flow rate after throttling by the orifice plate increases to 2-4 m / s, thereby achieving the optimal demisting flow rate range.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0026] This invention provides a device and method for enhancing desulfurization in a liquid column tower by adding a gas guide coil. By adding a gas guide coil, the gas that has been reacted in the liquid column tower is reintroduced into the absorbent liquid for aeration, and secondary absorption and mass transfer are carried out to achieve better absorption effect and significantly improve desulfurization efficiency. At the same time, a throttling orifice plate is added, and the gas overflowing after aeration has a higher velocity after passing through the throttling orifice plate, resulting in a lower mist content in the outlet gas.

[0027] The method described in this invention has the advantages of high desulfurization efficiency, good desulfurization effect, and low mist content in the outlet gas. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the process for enhancing the desulfurization of a liquid column tower by adding a gas guide coil, as described in this invention.

[0029] Figure 2 This is a front view of the air guide coil described in this invention;

[0030] Figure 3 This is a side view of the air guide coil described in this invention;

[0031] Figure 4 This is a front view of the throttling orifice plate described in this invention;

[0032] Figure 5 This is a side view of the throttling orifice plate described in this invention;

[0033] Figure 6This is a schematic diagram of the process flow for multi-stage Venturi injection enhanced flue gas desulfurization as described in this invention.

[0034] Figure 7 This is a schematic diagram illustrating the principle of multi-stage Venturi jetting of droplets as described in this invention;

[0035] Figure 8 for Figure 7 A cross-sectional view of the AA side of the reverse spray tower described in the text;

[0036] Figure 9 This is a schematic diagram of the external structure of the Venturi injector described in this invention;

[0037] Figure 10 This is a cross-sectional view of the internal structure of the Venturi injector described in this invention;

[0038] The components are as follows: 1-Absorber main body; 2-Reverse spray tower; 3-Tail gas inlet; 4-Tail gas outlet; 5-Liquid distributor; 6-Liquid jet injection device; 6-1 Primary Venturi ejector; 6-2 Secondary Venturi ejector; 6-3 Tertiary Venturi ejector; 6-4 Venturi liquid inlet; 6-5 Venturi liquid outlet; 6-6 Self-priming air inlet; 6-7 Water inlet section; 6-8 Mixing section; 6-9 Water outlet section; 6-10 Throat; 7-Circulation pipeline; 7-1 Water pump; 7-2 Main tower liquid outlet valve; 7-3 Ejector liquid inlet valve; 7-4 First pressure gauge; 7-5 Second pressure gauge; 7-6 Liquid flow meter; 8-Spray device; 9-Demister; 10-Liquid inlet; 10-1 Liquid inlet valve; 11-Drainage pipeline; 11-1 12-Drain valve; 12-Spray liquid pipeline; 12-1 Spray device valve; 13-Air guide coil; 13-1 Air guide plate; 13-2 Air guide pipe; 14-Throttle orifice plate; 15-Fan. Detailed Implementation

[0039] The present invention will be further described in detail below with reference to the embodiments. It should be understood that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the content of the present invention still fall within the scope of protection of the present invention.

[0040] Example 1

[0041] The present invention provides a device for enhancing desulfurization of a liquid column tower by adding a gas guide coil, such as... Figure 1As shown, the enhanced liquid column tower desulfurization device includes an absorption tower body 1 and a reverse spray tower 2 whose lower end is connected to the side wall of the absorption tower body 1. The upper part of the reverse spray tower 2 is provided with a tail gas inlet 3, which is connected to a fan 15 for blowing in tail gas. The top of the absorption tower body 1 is provided with a tail gas outlet 4, and the bottom of the absorption tower body 1 is used to store absorbent liquid. A spray device 8 is provided at the top of the reverse spray tower 2 for spraying small droplets to react with the tail gas just entering the reverse spray tower 2. Inside the reverse spray tower 2, below the tail gas inlet 3, is installed... The system includes a liquid distributor 5 and a liquid jet injection device 6 whose lower end is fixedly connected to the liquid distributor 5. The liquid jet injection device 6 comprises several liquid jet injectors. The inlet of the liquid distributor 5 is connected to the bottom of the absorption tower body 1 via a circulation pipeline 7, which is used to transport the absorbent stored at the bottom of the absorption tower body 1 to the liquid distributor 5 for distribution, and then spray it into the reverse spray tower 2 through the liquid jet injection device 6 to react and absorb the tail gas. A water pump 7-1 is installed on the circulation pipeline 7. A gas guide coil 13 is installed at the lower end of the reverse spray tower 2, combined with... Figure 2-3 As shown, the gas guide coil 13 includes a gas guide plate 13-1 and several gas guide pipes 13-2 connected to the gas guide plate 13-1. The gas guide plate 13-1 is fixedly connected to the inner wall of the reverse spray tower 2. The gas guide pipes 13-2 are immersed in the absorbent liquid at the bottom of the absorption tower body 1, and are used to pass the gas absorbed by the liquid column reaction into the absorbent liquid at the bottom of the absorption tower body 1 for aeration, and to carry out secondary enhanced reaction absorption; combined with Figure 4-5 As shown, inside the absorption tower body 1, above the connection between the absorption tower body 1 and the reverse spray tower 2, a throttling orifice plate 14 and a demister 9 are arranged in sequence. The gas after aeration reaction absorption is accelerated to the range of the optimal demisting speed through the throttling orifice plate 14, and then discharged from the exhaust gas outlet 4 after being demisted by the demister 9.

[0042] Furthermore, the air guide plate 13-1 is vertically connected to the inner wall of the reverse spray tower 2, and the air guide pipe 13-2 is immersed in the lower part of the absorbent liquid at the bottom of the absorption tower body 1.

[0043] Furthermore, the gas guide coil 13 is made of PVC material, and the number and diameter of the gas guide pipes 13-2 are adjusted according to the flue gas treatment capacity of the liquid column tower. The diameter of the gas guide pipes 13-2 is generally set to 1-5cm, and the number is adjusted according to the size of the gas guide coil 13-2.

[0044] Furthermore, the orifice plate 14 is made of polypropylene, and the thickness of the orifice plate 14 is 3-5cm, with an opening diameter ranging from 0.1-1.5mm, which can be adjusted accordingly based on the different demisters used.

[0045] Furthermore, a liquid inlet 10 is provided on the side wall of the absorption tower body 1 for introducing the absorbent liquid required by the enhanced liquid column tower desulfurization device into the bottom of the absorption tower body 1; the liquid inlet 10 is connected to a liquid inlet valve 10-1 for controlling the feeding of absorbent liquid into the absorption tower body 1.

[0046] Furthermore, the circulation pipeline 7 is provided with a main tower outlet valve 7-2 and an ejector inlet valve 7-3 in sequence along the water flow direction. According to actual operating requirements, the main tower outlet valve 7-2 and the ejector inlet valve 7-3 can be set to one or more. The circulation pipeline 7 is provided with a liquid flow meter 7-6, and a first pressure gauge 7-4 and a second pressure gauge 7-5 are provided in sequence along the water flow direction to monitor the flow and pressure on the circulation pipeline 7. The circulation pipeline 7 is connected to a drain pipeline 11, and the drain pipeline 11 is provided with a drain valve 11-1 to control the discharge of the absorbent liquid in the main body 1 of the absorption tower.

[0047] Preferably, the drain line 11 is located between the main tower outlet valve 7-2 and the ejector inlet valve 7-3 on the circulation line 7, and is located between the first pressure gauge 7-4 and the second pressure gauge 7-5, so that the first pressure gauge 7-4 and the second pressure gauge 7-5 are used to monitor the pressure of the outlet section and the circulation section on the circulation line 7, respectively.

[0048] Furthermore, the spraying device 8 is connected to an external spraying liquid pipeline, or to a spraying liquid pipeline 12 connected to the bottom of the absorption tower body 1; preferably, the spraying liquid pipeline 12 is connected to the circulation pipeline 7, and the absorbent liquid in the absorption tower body 1 is used for spraying at the top of the counter-spray tower 2, and a spraying device valve 12-1 is provided on the spraying liquid pipeline 12 to control the feed of the spraying liquid.

[0049] The process of enhancing flue gas desulfurization using the device with added air guide coil to enhance liquid column tower desulfurization occurs sequentially in the reverse spray tower 2 and the main body of the absorption tower 1. The specific method for enhancing flue gas desulfurization is as follows:

[0050] Sulfur dioxide-containing exhaust gas enters the reverse spray tower 2 through the exhaust gas inlet 3 via the blower 15. It first reacts with small droplets sprayed from the spray device 8 at the top of the reverse spray tower 2; then it reacts with the liquid column sprayed from the liquid column spray device 6 for absorption. Under the pressure of the blower 15, the reacted gas is introduced into the absorbent liquid in the main body 1 of the absorption tower through the air guide coil 13 at the bottom of the reverse spray tower 2 for aeration, undergoing secondary absorption. Simultaneously, the absorbent liquid in the reverse spray tower 2 circulates back into the main body 1 of the absorption tower through the air guide coil 13. The reacted gas is accelerated by the orifice plate 14 and flows through the demister 9 to achieve optimal demisting effect. The demisted gas is discharged from the exhaust gas outlet 4. Because this method involves absorption of sulfur-containing exhaust gas via liquid column spray followed by secondary aeration, it significantly improves desulfurization efficiency. Furthermore, the addition of the orifice plate increases the gas flow velocity, resulting in lower mist content in the outlet gas.

[0051] Furthermore, the spray device 8 generates a large number of tiny droplets with a diameter of 30-120μm, which are initially absorbed by the exhaust gas entering the reverse spray tower 2.

[0052] Furthermore, in order to ensure that the absorbent liquid smoothly enters the liquid jet injector 6-1 and generates a liquid jet of sufficient height, a certain pressure needs to be provided by the water pump 7-1. Specifically, the water pressure of the water pump 7-1 reaches 0.35 MPa, and the head is set to be above 35 m.

[0053] Furthermore, the gas velocity after aeration by the air guide coil 13 is 0.5-1.0 m / s, and the gas velocity increases to 2-4 m / s after passing through the throttling orifice plate 14, reaching the optimal demisting velocity range.

[0054] Example 2

[0055] The apparatus and method described in Example 1, which uses an enhanced liquid column tower desulfurization system with an added gas guide coil, were used to treat SO2 emissions from a chemical plant with a concentration of approximately 1500 mg / m³. 3 The flue gas contains sulfur and has an inlet flow rate of 100,000 m³ / h. 3 / h, where the specific structure and parameters of the liquid column tower desulfurization device are set as follows:

[0056] The absorbent is sodium hydroxide; the water pump has a water pressure of 0.35 MPa and a head of 35 m.

[0057] The air guide coil is made of PVC material, the diameter of the air guide is set to 2cm, and the number is 40. The throttling orifice plate is made of polypropylene material, the thickness of the orifice plate is 4cm, and the opening diameter is 1.0mm.

[0058] After several days of stable operation, the SO2 concentration and alkali consumption at the exhaust outlet were measured, and the results are shown in the table below.

[0059]

[0060] Comparative Examples 1-2

[0061] The sulfur-containing flue gas described in Example 2 was treated using the enhanced liquid column tower desulfurization device and method described in Example 2, and the same inlet flow rate as in Example 2 was used. The difference was that the reverse spray tower of Comparative Example 1 did not have a liquid column injection device, while the device of Comparative Example 2 did not have a gas guide coil for aeration and secondary absorption.

[0062] After several days of stable operation, the SO2 concentration and alkali consumption at the exhaust outlet were measured, and the results are shown in the table below.

[0063]

[0064] As can be seen from the table above, under the condition that the SO2 inlet concentration is almost the same, the SO2 outlet concentration of Example 2 is lower than that of Comparative Example 1-2, the absorption efficiency is significantly higher than that of Comparative Example 1-2, and its alkali consumption is also lower than that of Comparative Example 1-2. In actual production, the SO2 tail gas absorption efficiency of Example 2 is high and the treatment cost is also significantly lower.

[0065] Example 3

[0066] Based on Example 1, a multi-stage Venturi injection enhanced flue gas desulfurization device is further provided, wherein the liquid column injection device 6 is a multi-stage Venturi injector, such as... Figure 6-8 As shown, the multi-stage Venturi ejector 6 includes a first-stage Venturi ejector 6-1, a second-stage Venturi ejector 6-2, and a third-stage Venturi ejector 6-3. The first-stage, second-stage, and third-stage Venturi ejectors 6-1, 6-2, and 6-3 are three different Venturi ejection devices with different structures, representing high-column, medium-column, and low-column Venturi ejection devices 6-1, 6-2, and 6-3, respectively, used to generate liquid columns of different heights and droplet sizes. Figure 9-10 As shown, each Venturi injection device includes a lower Venturi inlet 6-4 and an upper Venturi outlet 6-5, with a self-priming air inlet 6-6 on the side wall; the Venturi injection device includes a water inlet section 6-7, a mixing section 6-8, and a water outlet section 6-9 connected in sequence, with the water inlet section 6-7 and the water outlet section 6-9 respectively connected to the Venturi inlet 6-4 and the Venturi outlet 6-5; a throat 6-10 is radially arranged in the mixing section 6-8 and communicates with the mixing section 6-8, and the throat 6-10 is connected to the self-priming air inlet 6-6; wherein:

[0067] The high-pressure jet venturi jet device 6-1 is used to generate tiny droplets. The lengths of the inlet section 6-7 and the outlet section 6-9 are adjusted to 2-5 cm as needed, the length of the mixing section 6-8 is 3-6 cm, the length-to-diameter ratio of the mixing section 6-8 is 5-7, and the throat diameter of the throat tube 6-10 is 1-2 mm. Preferably, two throat tubes 6-10 are radially opposite to each other in the mixing section 6-8 to increase the intake volume, i.e., increase the internal circulating gas volume, and at the same time increase the jet height. The throat convergence angle α of the inlet section 6-7 and the throat expansion angle β of the outlet section 6-9 are 25°-30°.

[0068] The venturi jet device 6-2 of the central jet column is used to generate small droplets. The lengths of the inlet section 6-7 and the outlet section 6-9 are adjusted to 2-4 cm as needed, the length of the mixing section 6-8 is 3-5 cm, the length-to-diameter ratio of the mixing section 6-8 is 4-6, and the throat diameter of the throat tube 6-10 is 3-4 mm. Preferably, a throat tube 6-10 is opened radially in the mixing section 6-8. The throat convergence angle α of the inlet section 6-7 and the throat expansion angle β of the outlet section 6-9 are 30°-35°.

[0069] The low-pressure jet venturi jet device 6-3 is used to generate large droplets. The lengths of the inlet section 6-7 and the outlet section 6-9 are adjusted to 1-3 cm as needed, the length of the mixing section 6-8 is 2-4 cm, the length-to-diameter ratio of the mixing section 6-8 is 2-4, and the throat diameter of the throat tube 6-10 is 5-6 mm. Preferably, a throat tube 6-10 is opened radially in the mixing section 6-8. The throat convergence angle α of the inlet section 6-7 and the throat expansion angle β of the outlet section 6-9 are 35°-40°.

[0070] Furthermore, one of the throats 6-10 of the high-jet venturi injection device 6-1 is aligned with the throats 6-10 of the medium-jet venturi injection device 6-2 and the low-jet venturi injection device 6-3.

[0071] The exhaust gas entering the reverse spray tower 2 reacts and is absorbed by the liquid droplets ejected from the first-stage, second-stage, and third-stage Venturi injectors 6-1, 6-2, and 6-3, respectively; the liquid column height of the multi-stage Venturi injector 6 is 0.5-3.5m, and the liquid column height is based on the height of the Venturi outlet of the Venturi injector, which is the height of the liquid column.

[0072] The gas-liquid ratio of the first-stage Venturi injector 6-1 is 8-10, the liquid column spray height is 2.0-3.5m, and droplets with a diameter in the range of 120-250μm are generated at the highest point of the liquid column spray. Due to the small droplet size and large mass transfer specific surface area, the desulfurization process can be enhanced after spray absorption.

[0073] The gas-liquid ratio of the secondary Venturi injector 6-2 is 3-5, the liquid column spray height is 1.0-2.5m, and small droplets with a diameter in the range of 300-550μm are generated at the highest point of the liquid column spray. Within this range, the main mass transfer process of desulfurization in the reverse spray tower 2 is completed.

[0074] The gas-liquid ratio of the three-stage Venturi injector 6-3 is 1-3, the jet height of the liquid column is 0.5-1.0m, and droplets with a diameter in the range of 1000-2500μm are generated at the highest point of the liquid column. The droplets are large, and a large number of flake droplets are generated during the liquid column's descent. These large droplets can capture mist droplets entrained in the gas phase and reduce the mist content in the gas phase.

[0075] The multi-stage Venturi ejector 6, with three stages of different structures fixed to the liquid distributor 5, generates droplets of different sizes, resulting in high turbulence and gas-liquid interweaving within the reverse spray tower 2. The height of the liquid column and the size of the droplets generated by the three stages of Venturi ejectors are controlled by adjusting the liquid flow meter and pump pressure on the circulation pipeline 7, in conjunction with the different structures of the three stages. The liquid columns and droplets from the three stages collide during their descent and dispersion, continuously generating new gas-liquid contact surfaces and enhancing mass transfer. Simultaneously, the self-priming inlet 6-6 of the Venturi ejector allows for the absorption of tail gas within the tower through negative pressure, enabling multiple cycles of tail gas absorption and significantly increasing tail gas absorption efficiency. Because this method provides more efficient mass transfer, it significantly reduces the consumption of absorbent liquid.

[0076] This application provides a detailed description, the purpose of which is to enable those skilled in the art to understand and implement the content of this application, but it should not be used to limit the scope of protection of this application. All equivalent changes or modifications made in accordance with the spirit and essence of this application should be included within the scope of protection of this application.

Claims

1. A device for enhancing desulfurization of a liquid column tower by adding a gas guide coil, characterized in that, The enhanced liquid column tower desulfurization device includes an absorption tower body and a reverse spray tower whose lower end is connected to the side wall of the absorption tower body, wherein: The upper part of the reverse spray tower is provided with an exhaust gas inlet, which is connected to a fan; the top of the absorption tower body is provided with an exhaust gas outlet, and the bottom of the absorption tower body is used to store the absorbent liquid. Inside the reverse spray tower, a liquid distributor and a liquid jet injection device connected to the liquid distributor at the lower end are installed below the exhaust gas inlet. The liquid inlet of the liquid distributor is connected to the bottom of the absorption tower body through a circulation pipeline, and a water pump is installed on the circulation pipeline. The lower end of the reverse spray tower is provided with a gas guide coil. The gas guide coil includes a gas guide plate and several gas guide pipes connected to the gas guide plate. The gas guide plate is fixedly connected to the inner wall of the reverse spray tower around its perimeter. The gas guide pipes are immersed in the absorbent liquid at the bottom of the main body of the absorption tower and are used to pass the gas absorbed by the liquid column reaction into the absorbent liquid at the bottom of the main body of the absorption tower for aeration and secondary enhanced reaction absorption. The air guide plate is vertically connected to the inner wall of the reverse spray tower, and the air guide pipe is immersed in the lower part of the absorbent liquid at the bottom of the main body of the absorption tower. Inside the main body of the absorption tower, a throttling orifice plate and a demister are sequentially arranged above the connection between the main body of the absorption tower and the reverse spray tower.

2. The apparatus for enhanced liquid column desulfurization according to claim 1, characterized in that, The air guide coil is made of PVC material, and the diameter of the air guide tube is 1-5cm.

3. The apparatus for enhanced liquid column desulfurization according to claim 1, characterized in that, The orifice plate is made of polypropylene, and the thickness of the orifice plate is 3-5cm, with an opening diameter ranging from 0.1-1.5mm.

4. A method for enhanced desulfurization using the enhanced liquid column tower desulfurization apparatus as described in claim 1 or 2, characterized in that, The specific steps are as follows: Sulfur dioxide-containing exhaust gas enters the reverse spray tower through the exhaust gas inlet via the blower, reacting and being absorbed by the liquid column sprayed by the liquid column injection device. The reacted gas, under the pressure of the blower, is then introduced into the absorbent liquid inside the main body of the absorption tower through the air guide coil at the bottom of the reverse spray tower for aeration, undergoing secondary absorption. Simultaneously, the absorbent liquid in the reverse spray tower circulates back into the main body of the absorption tower through the air guide coil. Inside the main body of the absorption tower, a throttling orifice plate and a demister are sequentially installed above the connection between the main body of the absorption tower and the reverse spray tower. The gas after aeration and reaction is accelerated by the throttling orifice plate and flows through the demister; the demisted gas is then discharged from the exhaust gas outlet.

5. The enhanced desulfurization method according to claim 4, characterized in that, The top of the reverse spray tower is equipped with a spraying device that generates a large number of tiny droplets with a diameter of 30-120μm. The exhaust gas entering the reverse spray tower first reacts with the tiny droplets sprayed by the spraying device for preliminary absorption.

6. The enhanced desulfurization method according to claim 4, characterized in that, The water pump has a water pressure of 0.35 MPa and a head of over 35 m.

7. The enhanced desulfurization method according to claim 4, characterized in that, The gas velocity after aeration by the gas guide coil is 0.5-1.0 m / s, and the gas velocity increases to 2-4 m / s after throttling by the orifice plate.

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