Kinetic wave flue gas scrubbing purification system

Abstract

The utility model relates to smelting flue gas purification, specifically related to a kind of power wave flue gas washing purification system, including the power wave washing unit and gas cooling tower arranged sequentially in upstream and downstream, and the power wave washing unit includes liquid pool, and the pool top of liquid pool is respectively provided with the vertical inlet flue pipe and outlet flue pipe, and the second nozzle is arranged in outlet flue pipe and the liquid injection direction of second nozzle is downward, and second nozzle is connected with clean liquid medium pipeline. Flue gas with entrained mist is further washed and purified by clean liquid before entering gas cooling tower, effectively realizing the capture and removal of solid mist, and also achieving further dust removal and cooling of dust-containing flue gas. The solid content of the washing liquid tank in the tower is significantly improved, the heat exchanger and the filler are less likely to scale, and the maintenance frequency of the heat exchanger and the filler is reduced.

Description

Technical Field

[0001] This utility model relates to the purification of smelting flue gas, specifically to a dynamic wave flue gas scrubbing and purification system. Background Technology

[0002] A dynamic wave scrubber is an industrial flue gas purification and washing device. High-temperature flue gas and washing liquid collide and come into full contact in a counter-current high speed inside the reverse spray pipe of the dynamic wave scrubber, completing the gas-liquid mass transfer and heat transfer process, thereby achieving the purpose of cooling and removing dust from the flue gas.

[0003] The patent document entitled "Overflow Weir System" (publication number CN109731424B) discloses a technical solution comprising a primary dynamic wave scrubbing unit, a gas cooling tower, and a secondary dynamic wave scrubbing unit arranged sequentially upstream and downstream. A primary pump pumps the scrubbing liquid in the primary scrubbing liquid storage tank of the primary dynamic wave scrubbing unit through a first pipeline to the nozzles inside the primary scrubbing cylinder of the primary dynamic wave scrubbing unit. The liquid sprayed from the nozzles collides with the flue gas at high speed in a counter-current manner inside the cylinder, achieving full contact and initial cooling and dust removal of the flue gas. Subsequently, the flue gas enters the gas cooling tower, where the nozzles inside the gas cooling tower achieve secondary cooling and dust removal.

[0004] The patent document entitled "Power Wave Purification Device for Smelting Flue Gas" (publication number CN1446616A) discloses a technical solution including a first-stage power wave back-jet scrubber, a gas cooling tower, and a second-stage power wave back-jet scrubber. The flue gas first enters the first-stage back-jet scrubber for preliminary purification, and then undergoes gas-liquid separation in the liquid collection tank at the bottom of the first-stage back-jet scrubber before entering the gas cooling tower. In the gas cooling tower, most of the moisture in the flue gas is condensed. The flue gas after passing through the gas cooling tower enters the second-stage back-jet scrubber for further purification, and then enters the first and second-stage electrostatic precipitators.

[0005] In existing technologies, the primary dynamic wave scrubbing unit can remove most of the dust from the flue gas. However, some dust will still be discharged with the airflow. Therefore, flue gas purification systems generally include gas cooling towers and even secondary dynamic wave scrubbing units to further purify the flue gas. In the gas cooling tower, the scrubbing liquid is cooled by a heat exchanger and then pumped to nozzles at the top of the tower. The sprayed scrubbing liquid comes into contact with the incoming gas again inside the tower for further purification. The sprayed scrubbing liquid then flows back into the scrubbing liquid storage tank inside the gas cooling tower for recycling. Currently, the flue gas at the outlet of the first-stage power wave generally contains mist and droplets. These mist and droplets contain a lot of impurities. As the mist and dust washed down from the gas cooling tower enter the washing liquid storage tank, although the solid content of the washing liquid in the storage tank is not as high as that of the first-stage power wave washing unit, it is still relatively high. When this washing liquid is recycled, it causes significant scaling of the heat exchanger and the filter packing in the tower. This not only affects the heat exchange efficiency and the filtration performance of the packing, but also leads to a significant increase in the maintenance frequency of the heat exchanger and filter packing. Summary of the Invention

[0006] This invention provides a dynamic wave flue gas scrubbing and purification system that reduces the structural velocity of the scrubbing liquid heat exchanger and the packing material inside the gas cooling tower, ensuring the heat exchange efficiency and filtration performance of the heat exchanger, and reducing the maintenance frequency of the heat exchanger and filter packing material.

[0007] To achieve the above objectives, the technical solution adopted is as follows: a dynamic wave flue gas scrubbing and purification system, comprising a dynamic wave scrubbing unit and a gas cooling tower arranged sequentially upstream and downstream. The dynamic wave scrubbing unit includes a liquid collection tank, and a vertically positioned flue gas inlet pipe and a flue gas outlet pipe are respectively installed on the top of the liquid collection tank. A first nozzle is installed in the flue gas inlet pipe, and the liquid spray direction of the first nozzle is upward. The first nozzle is connected to the liquid collection tank by a first pipeline. A primary pump pumps the scrubbing liquid in the liquid collection tank to the first nozzle through the first pipeline. The flue gas outlet pipe is connected to the gas cooling tower through a gas guide pipe. A second nozzle is installed in the flue gas outlet pipe, and the liquid spray direction of the second nozzle is downward. The second nozzle is connected to a clean liquid medium pipeline.

[0008] Compared with the prior art, the technical effects of this utility model are as follows: A second nozzle is installed in the flue gas outlet pipe of the first-stage power wave washing unit, and the liquid spray direction of the second nozzle is downward. The second nozzle is connected to the clean liquid medium pipeline. Before entering the gas cooling tower, the flue gas carrying mist is further washed and purified by the clean liquid, which effectively captures and removes solid mist, and at the same time further removes dust and cools the dusty flue gas. The solid content of the washing liquid storage tank in the tower is significantly improved, and the heat exchanger and packing are less prone to scaling, which ensures the heat exchange efficiency of the heat exchanger and the filtration performance of the packing, reduces the maintenance frequency of the heat exchanger and packing, and saves maintenance costs. Attached Figure Description

[0009] Figure 1 This is a schematic diagram of the flue gas scrubbing and purification system of this utility model;

[0010] Figure 2 This is a schematic diagram of the condensate discharge outlet and baffle.

[0011] Figure 3 for Figure 2 KK-direction sectional view;

[0012] Figure 4 This is a schematic diagram of the assembly of the second nozzle, the second pipeline, and the smoke outlet pipe. Detailed Implementation

[0013] The following is in conjunction with the appendix Figure 1-4 The present invention will be further described in detail below, including related content:

[0014] A dynamic wave flue gas scrubbing and purification system includes a dynamic wave scrubbing unit 10 and a gas cooling tower 20 arranged sequentially upstream and downstream. The dynamic wave scrubbing unit 10 includes a liquid collection tank 11. A vertically mounted inlet pipe 111 and an outlet pipe 112 are respectively installed on the top of the liquid collection tank 11. A first nozzle 12 is installed in the inlet pipe 111, and the liquid spray direction of the first nozzle 12 is upward. The first nozzle 12 is connected to the liquid collection tank 11 by a first pipeline 13. A primary pump 14 pumps the scrubbing liquid in the liquid collection tank 11 to the first nozzle 12 through the first pipeline 13. The outlet pipe 12 is connected to the gas cooling tower 20 through a gas guide pipe 21. A second nozzle 15 is installed in the outlet pipe 112, and the liquid spray direction of the second nozzle 15 is downward. The second nozzle 15 is connected to a clean liquid medium pipeline.

[0015] In the above technical solution, a second nozzle 15 is installed inside the exhaust pipe 112 of the primary dynamic wave scrubbing unit 10, with the liquid spray direction of the second nozzle 15 pointing downwards. The second nozzle 15 is connected to the clean liquid medium pipeline. When the flue gas carrying mist flows through the exhaust pipe 112, it collides counter-currently with the scrubbing liquid sprayed from the second nozzle 15 and makes full contact. Before entering the gas cooling tower 20, the flue gas carrying mist is further scrubbed and purified by the clean liquid, effectively capturing and removing solid-containing mist. At the same time, the installation of the second nozzle 15 also further removes dust and cools the dust-laden flue gas. The solid content of the scrubbing liquid storage tank in the tower is significantly improved, and the heat exchanger and packing are less prone to scaling, ensuring the heat exchange efficiency of the heat exchanger and the filtration performance of the packing, reducing the maintenance frequency of the heat exchanger and packing, and saving maintenance costs. The term "clean liquid" here is a relative term, referring to a liquid that is cleaner than the scrubbing liquid in the primary dynamic wave scrubbing unit 10.

[0016] It should be noted that a secondary dynamic wave scrubbing unit can be installed immediately downstream of the gas cooling tower 20. The secondary dynamic wave scrubbing unit has the same overall structure as the primary dynamic wave scrubbing unit 10. This part has been clearly described in the prior art. However, the process water of the secondary dynamic wave scrubbing unit can be directed to its flue gas outlet nozzle to collide and contact with the flue gas in the flue gas outlet again in a reverse direction, instead of directly pumping the process water of the secondary dynamic wave scrubbing unit into its liquid collection tank. This is also to use the process water of the secondary dynamic wave scrubbing unit to achieve re-scrubbing.

[0017] The acid transfer method of the washing liquid is exactly opposite to the flow direction of the flue gas. The secondary dynamic wave washing unit is connected to the process water supply. The acid transfer of the washing liquid from the secondary dynamic wave washing unit to the gas cooling tower 20, the acid transfer of the washing liquid from the gas cooling tower 20 to the primary dynamic wave washing unit 10, and the acid transfer of the primary dynamic wave washing unit 10 to the sedimentation tank, so that the washing liquid of the entire flue gas purification system remains relatively clean.

[0018] As a preferred embodiment, the second nozzle 15 is connected to the gas cooling tower 20 through the second pipeline 22. A secondary pump 23 is installed on the second pipeline 22, and the secondary pump 23 pumps the washing liquid in the gas cooling tower 20 to the second nozzle 15 through the second pipeline 22.

[0019] In this design, the solid content of the washing liquid in the gas cooling tower 20 is significantly reduced compared to the primary dynamic wave washing unit 10. Furthermore, the distance from the gas cooling tower 20 to the flue gas outlet pipe 112 is much shorter than that of the secondary dynamic wave washing unit. Therefore, the washing liquid in the storage tank of the gas cooling tower 20 is preferably used as the cleaning liquid for the second nozzle 15, eliminating the need for a separate source of cleaning liquid. Simultaneously, this arrangement eliminates the need for a separate cross-flow pipeline between the gas cooling tower 20 and the primary dynamic wave washing unit 10; the second pipeline 22 and the second nozzle 15 are sufficient to achieve the cross-flow operation between the gas cooling tower 20 and the primary dynamic wave washing unit 10.

[0020] As a preferred embodiment, the gas guide pipe 21 includes a horizontal pipe section 211 adjacent to the gas cooling tower 20. The core of the horizontal pipe section 211 is oriented horizontally. A condensate outlet 2111 is provided on the bottom wall of the horizontal pipe section 211. The condensate outlet 2111 is connected to the slurry pool 11 through a third pipe 24. The height of the connection position of the third pipe 24 on the slurry pool 11 is lower than the liquid level in the slurry pool 11, and the location of the condensate outlet 2111 is higher than the liquid level in the slurry pool 11.

[0021] In this design, although the second nozzle 15 can effectively capture and remove the mist entrained in the flue gas, some dust-laden droplets will still enter the air guide pipe 21 under the action of the airflow and condense into a stream inside the pipe, further entering the gas cooling tower 20. Therefore, a condensate outlet 2111 is provided on the horizontal section 211 of the air guide pipe 21. The condensate outlet 2111 is connected to the liquid accumulation tank 11 of the first-stage dynamic wave scrubbing unit 10 through a third pipe 24. Before entering the gas cooling tower 20, the condensate formed in the air guide pipe 21 will be discharged from the condensate outlet 2111 to the liquid accumulation tank 11 of the first-stage dynamic wave scrubbing unit 10, thereby preventing solid condensate from entering the gas cooling tower 20 and reducing the amount of impurities entering the gas cooling tower 20.

[0022] It should be noted that the above scheme is not intended to completely block the dust-laden droplets in the flue gas upstream of the gas cooling tower 20, but rather to minimize the amount of dust entering the gas cooling tower 20. When the flue gas containing liquid flows through the duct 21, due to the meandering pipe, most of the dust-laden droplets will adhere to the pipe wall and condense into a stream. Only a small portion of the droplets or dust will enter the gas cooling tower 20 with the flue gas.

[0023] In addition, the location of the condensate outlet 2111 is higher than the liquid level in the condensate tank 11. This is to create a height difference between the condensate outlet 2111 and the liquid level in the condensate tank 11, so that the condensate can flow normally into the condensate tank 11 under the action of gravity. The connection point of the third pipe 24 on the condensate tank 11 is lower than the liquid level in the condensate tank 11. This is to eliminate the possibility of flue gas directly entering the third pipe 24 from the condensate tank 11.

[0024] Furthermore, combined Figure 1 and Figure 2 As shown, to ensure the effective discharge of condensate formed within the gas duct 21, the entire gas duct 21 gradually descends from the flue gas outlet 112 to the gas cooling tower 20, with the horizontal pipe section 211 located at the lowest point of the entire gas duct 21. The condensate within the gas duct 21 will eventually flow into the lowest horizontal pipe section 211 and be further discharged through the condensate outlet 2111.

[0025] Furthermore, combined Figure 3 As shown, a baffle 2112 is installed in the cavity of the horizontal pipe section 211 located between the condensate outlet 2111 and the gas cooling tower 20. The baffle 2112 is located in the lower middle part of the cavity, and the side plate edge and bottom plate edge of the baffle 2112 are sealed to the inner wall of the horizontal pipe section 211.

[0026] In this design, the baffle 2112 is crescent-shaped and is designed to block the condensate. On the one hand, this means that the opening size of the condensate outlet 2111 does not need to be too large, and the third pipe 24 can use a small-diameter pipe, which reduces pipe costs and facilitates the overall layout of the pipes. On the other hand, by reasonably controlling the height of the upper edge of the baffle 2112, it is possible to effectively prevent some condensate from flowing past the edge of the small-diameter condensate outlet 2111 and entering the gas cooling tower 20.

[0027] Combination Figure 4 As shown, an auxiliary pipe 221 is connected to the end of the second pipe 22 near the second nozzle 15. The auxiliary pipe 221 passes through the flange on the smoke outlet pipe 112 and enters the cavity of the smoke outlet pipe 112. The second nozzle 15 is set on the suspension end of the auxiliary pipe 221 and is connected to the second pipe 22 through the auxiliary pipe 221. The flange on the smoke outlet pipe 112 is connected to the flange on the outer wall of the auxiliary pipe 221 or the flange on the end of the second pipe 22 to form a sealed fit.

[0028] In this design, considering that if the second pipe 22 were to extend directly into the smoke outlet pipe 112 to connect with the second nozzle 15, the pipe would likely suffer severe damage due to airflow scouring and temperature variations within the smoke outlet pipe 112, making overall replacement of the second pipe 22 costly and difficult, an auxiliary pipe 221 is connected to the end of the second pipe 22. This auxiliary pipe 221 replaces the second pipe 22 as it extends into the smoke outlet pipe 112. Subsequent maintenance only requires replacing the auxiliary pipe 221, reducing maintenance costs and facilitating inspection and maintenance.

[0029] Here, the auxiliary tube 221 can be made of fiberglass, which is resistant to high temperatures and erosion, and is relatively inexpensive. The second nozzle 15 can be a vortex nozzle, which is highly corrosion-resistant and not easily clogged, providing a highly efficient spraying effect and maximizing the capture of mist and dust in the flue gas.

[0030] Specifically, a first flange 2211 is provided on the outer wall of the auxiliary pipe 221, which is connected to the flange on the flue gas outlet pipe 112. A second flange 2212 is provided at the end of the auxiliary pipe 221 adjacent to the second pipe 22, which is connected to the flange at the output end of the second pipe 22. In this scheme, the first flange 2211 on the auxiliary pipe 221 is used to connect to and seal the flange on the flue gas outlet pipe 112, while the second flange 2212 on the auxiliary pipe 221 is used to connect to the second pipe 22.

[0031] like Figure 1As shown, the gas cooling tower 20 is further described here. A third nozzle 25 is provided in the upper middle part of the gas cooling tower 20, and the liquid spray direction of the third nozzle 25 is downward. The secondary pump 23 pumps the washing liquid in the gas cooling tower 20 to the third nozzle 25 through the fourth pipeline 26, and a plate heat exchanger 27 is provided on the fourth pipeline 26. The outlet of the gas guide pipe 21 is located between the third nozzle 25 and the liquid surface of the washing liquid in the gas cooling tower 20.

[0032] In this scheme, the secondary pump 23 pumps the washing liquid in the gas cooling tower 20 to the third nozzle 25 via the fourth pipeline 26. The washing liquid sprayed from the third nozzle 25 washes and cools the flue gas discharged from the gas guide pipe 21. The washing liquid then flows back to the washing liquid storage tank of the gas cooling tower 20, thus achieving circulating spraying in the gas cooling tower 20. During the circulation process, after absorbing heat from the flue gas, the washing liquid needs to be cooled by the plate heat exchanger 27. It is precisely because of the presence of the plate heat exchanger 27 that reducing the solid content in the washing liquid storage tank is crucial.

[0033] Furthermore, the gas cooling tower 20 is equipped with filter media 28, which is located below the third nozzle 25. The outlet of the air guide pipe 21 is located between the filter media 28 and the surface of the washing liquid inside the gas cooling tower 20. The washing liquid sprayed from the third nozzle 25 not only washes the flue gas but also washes the filter media 28 inside the tower, ensuring its filtration performance and reducing operating resistance. Reducing the solids content in the washing liquid storage tank also helps to reduce the scaling rate of the filter media 28.

[0034] As a preferred embodiment, the inlet of the second pipe 22 is located on the section of the fourth pipe 26 between the plate heat exchanger 27 and the third nozzle 25, and the second pipe 22 and the fourth pipe 26 are interconnected. This arrangement ensures that the washing liquid in the second pipe 22 has been cooled by the plate heat exchanger 27, and the washing liquid sprayed from the second nozzle 15 can effectively cool the flue gas in the flue gas outlet pipe 112.

[0035] like Figure 1 As shown, in the solution provided in this application, at least two primary pumps 14 and two secondary pumps 23 are each connected in parallel. The two pumps connected in parallel are switched on and off, so that when one pump fails, the other pump can be turned on to maintain the normal operation of the system.

Claims

1. A dynamic wave flue gas scrubbing and purification system, comprising a dynamic wave scrubbing unit (10) and a gas cooling tower (20) arranged sequentially upstream and downstream, wherein the dynamic wave scrubbing unit (10) includes a liquid collection tank (11), and a vertically mounted flue gas inlet pipe (111) and a flue gas outlet pipe (112) are respectively installed on the top of the liquid collection tank (11), a first nozzle (12) is installed in the flue gas inlet pipe (111) and the liquid spraying direction of the first nozzle (12) is upward, the first nozzle (12) and the liquid collection tank (11) are connected by a first pipeline (13), a primary pump (14) pumps the scrubbing liquid in the liquid collection tank (11) to the first nozzle (12) through the first pipeline (13), and the flue gas outlet pipe (112) and the gas cooling tower (20) are connected by a gas guide pipe (21), characterized in that: A second nozzle (15) is provided inside the smoke outlet pipe (112), and the liquid spraying direction of the second nozzle (15) is downward. The second nozzle (15) is connected to the clean liquid medium pipeline.

2. The dynamic wave flue gas scrubbing and purification system according to claim 1, characterized in that: The second nozzle (15) is connected to the gas cooling tower (20) through the second pipeline (22). A secondary pump (23) is installed on the second pipeline (22). The secondary pump (23) pumps the washing liquid in the gas cooling tower (20) to the second nozzle (15) through the second pipeline (22).

3. The dynamic wave flue gas scrubbing and purification system according to claim 1 or 2, characterized in that: The gas duct (21) includes a horizontal pipe section (211) adjacent to the gas cooling tower (20). The core of the horizontal pipe section (211) is in the horizontal direction. A condensate outlet (2111) is provided on the bottom wall of the horizontal pipe section (211). The condensate outlet (2111) is connected to the sump (11) through a third pipe (24). The height of the connection position of the third pipe (24) on the sump (11) is lower than the liquid level in the sump (11). The location of the condensate outlet (2111) is higher than the liquid level in the sump (11).

4. The dynamic wave flue gas scrubbing and purification system according to claim 3, characterized in that: The gas duct (21) gradually descends from the smoke outlet pipe (112) to the gas cooling tower (20), with the horizontal pipe section (211) located at the lowest point of the gas duct (21) pipeline.

5. The dynamic wave flue gas scrubbing and purification system according to claim 3, characterized in that: A baffle (2112) is installed in the cavity of the horizontal pipe section (211) located between the condensate outlet (2111) and the gas cooling tower (20). The baffle (2112) is located in the middle and lower part of the cavity, and the side plate edge and bottom plate edge of the baffle (2112) are sealed to the inner wall of the horizontal pipe section (211).

6. The dynamic wave flue gas scrubbing and purification system according to claim 2, characterized in that: An auxiliary pipe (221) is connected to the end of the second pipe (22) near the second nozzle (15). The auxiliary pipe (221) passes through the flange on the smoke outlet pipe (112) and enters the cavity of the smoke outlet pipe (112). The second nozzle (15) is set on the suspension end of the auxiliary pipe (221) and is connected to the second pipe (22) through the auxiliary pipe (221). The flange on the smoke outlet pipe (112) is connected to the flange on the outer wall of the auxiliary pipe (221) or the flange on the end of the second pipe (22) to form a sealed fit.

7. The dynamic wave flue gas scrubbing and purification system according to claim 6, characterized in that: A first flange (2211) is provided on the outer wall of the auxiliary pipe (221). The first flange (2211) is connected to the flange on the flue pipe (112). A second flange (2212) is provided at one end of the auxiliary pipe (22) near the second pipeline (22). The second flange (2212) is connected to the flange at the outlet of the second pipeline (22).

8. The dynamic wave flue gas scrubbing and purification system according to claim 2, characterized in that: A third nozzle (25) is provided in the upper middle part of the gas cooling tower (20) and the liquid spray direction of the third nozzle (25) is downward. The secondary pump (23) pumps the washing liquid in the gas cooling tower (20) to the third nozzle (25) through the fourth pipeline (26) and a plate heat exchanger (27) is provided on the fourth pipeline (26). The outlet of the gas guide pipe (21) is located between the third nozzle (25) and the liquid surface of the washing liquid in the gas cooling tower (20).

9. The dynamic wave flue gas scrubbing and purification system according to claim 8, characterized in that: The gas cooling tower (20) is equipped with filter packing (28) inside the tower. The filter packing (28) is located below the third nozzle (25). The outlet of the gas guide pipe (21) is located between the filter packing (28) and the surface of the washing liquid inside the gas cooling tower (20).

10. The dynamic wave flue gas scrubbing and purification system according to claim 8, characterized in that: The inlet of the second pipe (22) is located on the section of the fourth pipe (26) between the plate heat exchanger (27) and the third nozzle (25), and the second pipe (22) and the fourth pipe (26) are connected to each other.

11. The dynamic wave flue gas scrubbing and purification system according to claim 2, characterized in that: At least two primary pumps (14) and secondary pumps (23) are each connected in parallel.

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