Enhanced gas-liquid mass transfer device for desulfurization

Abstract

The utility model provides a kind of gas-liquid mass transfer device for enhanced desulfurization belongs to flue gas treatment technical field, including multiple gas-liquid mass transfer modules being arranged in absorption tower;Gas-liquid mass transfer module includes U type porous distributor and the turbulence unit body being arranged in porous distributor;Porous distributor includes bottom plate and side plate;Turbulence unit body includes outer cylinder, inner cylinder and turbulence blade;Outer cylinder inner wall is connected with the outer wall of inner cylinder by multiple turbulence blades.The utility model can effectively improve tower entrance flue gas uniformity;The bottom plate of porous distributor is arranged with multiple circular screen holes side by side, and when flue gas flows through circular screen hole, it generates acceleration effect due to cross-section contraction, blows up the upper liquid layer slurry to form dynamic liquid column;Initial stage due to flue gas entrance offset causes liquid column height difference, and when stable operation, liquid column falls to form uniform liquid layer, so that tower cross-section flue gas flow velocity deviation is less than or equal to 5%.

Description

Technical Field

[0001] This utility model relates to the field of flue gas treatment technology, and more specifically, it is an enhanced gas-liquid mass transfer device for desulfurization. Background Technology

[0002] Wet desulfurization technology is widely used in flue gas treatment due to its high desulfurization efficiency. In this process, alkaline droplet solution sprayed downwards from nozzles mixes with the upward-flowing raw flue gas inside the tower. Gaseous SO2 dissolves in the alkaline aqueous solution to form sulfurous acid (SO2·H2O), which subsequently dissociates to produce sulfite byproducts, such as bisulfite (HSO3). - ) and sulfite (SO3) 2- The process completes the absorption of SO2 from the original flue gas. Research shows that the degree of thorough mixing between the gas and liquid phases is the key factor affecting SO2 removal efficiency. In existing desulfurization tower design technology, factors such as the number of spray layers, the arrangement of nozzles in each spray layer, the direction of flue gas inlet, and the uniform distribution of flue gas flow have a significant impact on the mixing of the two phases, and thus significantly affect the SO2 removal efficiency.

[0003] The porous distributor can disperse flue gas and slurry into multiple small gas / liquid streams, avoiding the occurrence of local high-speed flow areas and short-circuiting phenomena in the tower, improving the uniformity of gas-liquid contact, increasing the gas-liquid contact area, and at the same time, the liquid holding layer formed by the slurry above the porous distributor will prolong the gas-liquid contact time, improve mass transfer efficiency, and effectively promote SO2 absorption. In addition, because the porous distributor improves the gas-liquid contact efficiency, it can achieve good desulfurization effect even at a low liquid-to-gas ratio, and can effectively reduce the energy consumption of circulating pump operation. Therefore, it is a commonly used gas-liquid mixing device in the tower.

[0004] When flue gas passes through the sieve holes below the porous distributor, the sudden narrowing of the flow cross-section generates a strong acceleration, pushing the liquid-holding slurry on the top surface of the porous distributor upward to form a liquid column. In the initial stage of operation, because the flue gas enters from one side of the bottom of the tower, the amount of flue gas passing through each sieve hole of the porous distributor is different, resulting in different liquid column heights. This creates anisotropy in the liquid column and flue gas movement trajectory above the porous distributor. During stable operation, the liquid column falls into the porous distributor to form a dynamically stable liquid-holding layer. Due to the anisotropy, the flue gas is uniformly distributed across the tower cross-section and continues to move upward to contact and react with the slurry in the spray layer above.

[0005] In actual operation, the movement of flue gas within the dynamic liquid holding layer can ensure sufficient contact between flue gas and slurry. However, after the liquid column breaks through the liquid holding layer, it forms dispersed large-diameter liquid agglomerates on the tower cross-section under various forces, which greatly reduces the contact opportunities between flue gas and large-diameter liquid agglomerates.

[0006] Therefore, based on the conventional porous distributor design, it is necessary to develop an enhanced gas-liquid mass transfer device for desulfurization, which increases the opportunity for the porous distributor to dynamically stabilize the liquid clump above the liquid holding layer and the flue gas, thereby further improving the desulfurization effect of the porous distributor. Summary of the Invention

[0007] The purpose of this invention is to address the problem that large-diameter liquid clusters disperse in the space above the dynamically stable liquid holding layer of conventional porous distributors, resulting in limited contact with flue gas and failing to fully utilize the increased gas-liquid contact area of ​​the porous distributor to improve desulfurization efficiency. This invention provides an enhanced gas-liquid mass transfer device for desulfurization. This invention effectively increases the contact between the liquid clusters above the dynamically stable liquid holding layer of the porous distributor and the flue gas, further improving the desulfurization effect. Simultaneously, it effectively reduces the liquid-to-gas ratio within the tower, lowering the energy consumption of the slurry circulation pump.

[0008] To achieve the above objectives, the technical solution of this utility model is as follows: an enhanced gas-liquid mass transfer device for desulfurization, characterized in that it includes multiple gas-liquid mass transfer modules disposed within an absorption tower; each gas-liquid mass transfer module includes a U-shaped porous distributor and a turbulence-inducing unit disposed within the porous distributor;

[0009] The porous distributor includes a base plate and a side plate; the base plate is provided with a plurality of circular sieve holes spaced apart.

[0010] The turbulence unit includes an outer cylinder, an inner cylinder, and turbulence blades; the inner wall of the outer cylinder is connected to the outer wall of the inner cylinder through multiple turbulence blades; the turbulence blades are arranged at an angle.

[0011] In the above technical solution, the lower edge of the outer cylinder is higher than the height of the liquid holding layer inside the porous distributor, and the upper edge is flush with the height of the side plate.

[0012] In the above technical solution, the lower edge of the inner cylinder is flush with the top surface of the bottom plate, and the upper edge is flush with the height of the side plate.

[0013] In the above technical solution, the outer wall of the bottom of the inner cylinder is provided with multiple cylinder wall openings at intervals along the circumferential direction; the height of the cylinder wall openings is lower than the height of the liquid holding layer inside the porous distributor.

[0014] In the above technical solution, each of the porous distributors is provided with two turbulence units along the length direction.

[0015] In the above technical solution, a stiffening plate is provided between the two turbulence units in each of the porous distributors; the stiffening plate is connected to the side plate.

[0016] In the above technical solution, the side plate has a first bolt hole and a second bolt hole; adjacent gas-liquid mass transfer modules are connected through the first bolt hole; the porous distributor is connected to the turbulence unit through the second bolt hole;

[0017] The stiffening plate has a third bolt hole; the two turbulence units in each of the porous distributors are connected by the third bolt hole.

[0018] In the above technical solution, the tilt angle of the turbulence blade is 30°-45°.

[0019] In the above technical solution, the lower edge of the outer cylinder is 50mm higher than the liquid holding layer inside the porous distributor.

[0020] In the above technical solution, the porous distributor is designed with a height H of 190mm, a length of 1500mm, and a width of 750mm; the circular sieve hole diameter is designed to be 35mm, and the porosity is set to 30%-35%; the outer cylinder height is 90mm and the diameter is 730mm; the inner cylinder height is 187mm and the diameter is 200mm.

[0021] Compared with the prior art, this utility model has the following advantages.

[0022] 1) This utility model can effectively improve the uniformity of flue gas distribution at the tower inlet; the bottom plate of the porous distributor is provided with multiple circular sieve holes arranged in parallel. When the flue gas flows through the circular sieve holes, the cross-sectional contraction generates an acceleration effect (flow velocity increases by 30%-50%), which blows the liquid holding layer above to form a dynamic liquid column; initially, the flue gas inlet is offset, resulting in differences in liquid column height. During stable operation, the liquid column falls to form a uniform liquid holding layer, so that the flue gas velocity deviation of the tower cross-section is ≤5%.

[0023] 2) This utility model has a dual crushing effect, which enhances the gas-liquid contact area and improves the desulfurization effect. The turbulence blades evenly distributed in the circumferential direction of the turbulence unit above the liquid holding layer can, on the one hand, cause the large-diameter liquid agglomerates (diameter > 5 mm) formed by the flue gas impacting the liquid holding layer to hit the lower surface of the turbulence blades and be broken into fine droplets of 1-3 mm; on the other hand, it can cause the droplets sprayed by the spray layer above to hit the upper surface of the turbulence blades and rotate along the turbulence blades to form a superimposed thin layer (thickness ≤ 0.5 mm), which greatly increases the gas-liquid contact specific surface area.

[0024] 3) This utility model has a swirling enhanced mass transfer effect; the swirling blades evenly distributed along the circumference in the swirling unit generate a swirling effect on the gas and liquid phases, which extends the flue gas flow path by 1.5-2 times and increases the contact time between the flue gas and the desulfurization slurry; at the same time, the vortex effect at the edge of the swirling blades enhances the disruption of the gas-liquid interfacial tension, breaks the gas phase into microbubbles (diameter <1mm), and increases the mass transfer coefficient by 25%-30%.

[0025] 4) This utility model has a simple structure and is easy to assemble; this utility model adopts factory prefabricated integrated components and is fixed on site with bolts, making installation convenient; for absorption towers that have already adopted porous distributors, during the modification, it is only necessary to place the turbulence unit on top of the original porous distributor and fix it with bolts.

[0026] 5) This utility model can effectively increase the chances of dynamic stabilization of the liquid clumps and flue gas above the liquid holding layer of the porous distributor, further improving the desulfurization effect; at the same time, it can effectively reduce the liquid-to-gas ratio in the tower and reduce the energy consumption of the slurry circulation pump. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the gas-liquid mass transfer device arrangement in this utility model.

[0028] Figure 2 This is a 3D view of the gas-liquid mass transfer module.

[0029] Figure 3 This is a schematic diagram of the structure of the turbulence unit.

[0030] Among them, 100-gas-liquid mass transfer module, 110-porous distributor, 111-base plate, 112-side plate, 1121-first bolt hole, 1122-second bolt hole, 113-circular sieve hole, 120-turbulence unit, 121-outer cylinder, 122-inner cylinder, 1221-cylinder wall opening, 123-turbulence blade, 200-stiffening plate, 210-third bolt hole, 300-support beam, 310-pressure strip plate, 320-pressure strip bolt, 400-connecting fixing bolt. Detailed Implementation

[0031] The following detailed description, in conjunction with the accompanying drawings, illustrates the implementation of this utility model. However, these descriptions do not constitute a limitation of the present utility model and are merely illustrative. Furthermore, the advantages of this utility model will become clearer and easier to understand through this description.

[0032] Referring to the accompanying drawings, an enhanced gas-liquid mass transfer device for desulfurization is characterized by comprising multiple gas-liquid mass transfer modules 100 disposed within an absorption tower; each gas-liquid mass transfer module 100 includes a U-shaped porous distributor 110 and a turbulence-inducing unit 120 disposed within the porous distributor 110; the U-shaped porous distributor 110 has its opening facing upwards.

[0033] like Figure 2 As shown, the porous distributor 110 includes a base plate 111 and a side plate 112; a plurality of circular sieve holes 113 are spaced apart on the base plate 111; the circular sieve holes 113 are used for the flow of slurry and flue gas;

[0034] like Figure 3As shown, the turbulence unit 120 includes an outer cylinder 121, an inner cylinder 122, and turbulence blades 123; the inner wall of the outer cylinder 121 is connected to the outer wall of the inner cylinder 122 through a plurality of turbulence blades 123; the turbulence blades 123 are inclined; the plurality of turbulence blades 123 are evenly spaced along the circumference of the inner wall of the outer cylinder 121.

[0035] The lower edge of the outer cylinder 121 is higher than the height of the liquid holding layer inside the porous distributor 110, and the upper edge is flush with the height of the side plate 112.

[0036] The lower edge of the inner cylinder 122 is flush with the top surface of the bottom plate 111, and the upper edge is flush with the height of the side plate 112.

[0037] To prevent slurry deposition inside the inner cylinder 122 from clogging the circular sieve holes 113 in the area of ​​the inner cylinder 122, a plurality of cylinder wall openings 1221 are provided at intervals along the circumferential direction on the outer wall of the bottom of the inner cylinder 122; the height of the cylinder wall openings 1221 is lower than the height of the liquid holding layer inside the porous distributor 110.

[0038] Each of the porous distributors 110 has two turbulence units 120 arranged along its length.

[0039] like Figure 2 As shown, a stiffening plate 200 is provided between the two turbulence units 120 in each of the porous distributors 110; the stiffening plate 200 is connected to the side plate 112; the stiffening plate 200 is used to strengthen the structural strength of the porous distributor 110 on the one hand, and to connect and fix the two turbulence units 120 on the other hand; at the same time, the stiffening plate 200 and the outer cylinder 121 of the turbulence unit together divide the flow area above the single gas-liquid mass transfer module 100 into more small zones, which helps to further improve the uniformity of flue gas velocity distribution in the tower.

[0040] The side plate 112 has a first bolt hole 1121 and a second bolt hole 1122; adjacent gas-liquid mass transfer modules 100 are connected through the first bolt hole 1121; the porous distributor 110 is connected to the turbulence unit 120 through the second bolt hole 1122.

[0041] The stiffening plate 200 has a third bolt hole 210; the two turbulence units 120 in each of the porous distributors 110 are connected through the third bolt hole 210.

[0042] The tilt angle of the baffle blade 123 is 30°-45°.

[0043] The lower edge of the outer cylinder 121 is 50 mm higher than the liquid holding layer inside the porous distributor 110.

[0044] The porous distributor 110 has a design height H of 190mm, a design length of 1500mm, and a design width of 750mm; the circular sieve hole 113 has a design diameter of 35mm and a porosity of 30%-35%; the outer cylinder 121 has a height of 90mm and a diameter of 730mm; and the inner cylinder 122 has a height of 187mm and a diameter of 200mm.

[0045] In practical use, such as Figure 1 As shown, the gas-liquid mass transfer modules 100 between adjacent support beams 300 in the absorption tower are fixed by pressure strips 310, and the pressure strips 310 are fastened to the support beams 300 by pressure strip bolts 320.

[0046] The perforated distributor 110 is made of thin steel plate that has been bent and punched into a U-shape.

[0047] All other unspecified parts belong to the prior art.

Claims

1. An enhanced gas-liquid mass transfer device for desulfurization, characterized in that: It includes multiple gas-liquid mass transfer modules (100) installed inside the absorption tower; the gas-liquid mass transfer module (100) includes a U-shaped porous distributor (110) and a turbulence unit (120) installed inside the porous distributor (110); The porous distributor (110) includes a base plate (111) and a side plate (112); the base plate (111) is provided with a plurality of circular sieve holes (113) at intervals; The turbulence unit (120) includes an outer cylinder (121), an inner cylinder (122), and turbulence blades (123); the inner wall of the outer cylinder (121) is connected to the outer wall of the inner cylinder (122) through a plurality of turbulence blades (123); the turbulence blades (123) are inclined.

2. The enhanced gas-liquid mass transfer device for desulfurization according to claim 1, characterized in that: The lower edge of the outer cylinder (121) is higher than the height of the liquid holding layer inside the porous distributor (110), and the upper edge is flush with the height of the side plate (112).

3. The enhanced gas-liquid mass transfer device for desulfurization according to claim 2, characterized in that: The lower edge of the inner cylinder (122) is flush with the top surface of the bottom plate (111), and the upper edge is flush with the height of the side plate (112).

4. The enhanced gas-liquid mass transfer device for desulfurization according to claim 3, characterized in that: The bottom outer wall of the inner cylinder (122) is provided with a plurality of cylinder wall openings (1221) at intervals along the circumferential direction; the height of the cylinder wall openings (1221) is lower than the height of the liquid holding layer inside the porous distributor (110).

5. The enhanced gas-liquid mass transfer device for desulfurization according to claim 1, characterized in that: Two turbulence units (120) are provided along the length direction within each of the porous distributors (110).

6. The enhanced gas-liquid mass transfer device for desulfurization according to claim 5, characterized in that: A stiffening plate (200) is provided between the two turbulence units (120) within each of the porous distributors (110); the stiffening plate (200) is connected to the side plate (112).

7. The enhanced gas-liquid mass transfer device for desulfurization according to claim 6, characterized in that: The side plate (112) has a first bolt hole (1121) and a second bolt hole (1122); adjacent gas-liquid mass transfer modules (100) are connected through the first bolt hole (1121); the porous distributor (110) is connected to the turbulence unit (120) through the second bolt hole (1122). The stiffening plate (200) has a third bolt hole (210); the two turbulence units (120) in each of the porous distributors (110) are connected through the third bolt hole (210).

8. The enhanced gas-liquid mass transfer device for desulfurization according to claim 1, characterized in that: The tilt angle of the turbulence blade (123) is 30°-45°.

9. The enhanced gas-liquid mass transfer device for desulfurization according to claim 4, characterized in that: The lower edge of the outer cylinder (121) is 50 mm higher than the height of the liquid holding layer inside the porous distributor (110).

10. The enhanced gas-liquid mass transfer device for desulfurization according to claim 5, characterized in that: The porous distributor (110) is designed with a height H of 190mm, a length of 1500mm, and a width of 750mm; the circular sieve hole (113) is designed with a diameter of 35mm and a porosity of 30%-35%; the outer cylinder (121) is 90mm high and 730mm in diameter; and the inner cylinder (122) is 187mm high and 200mm in diameter.

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