Efficient demisting device and demister flushing system

Abstract

The utility model discloses an efficient demisting device and a demister flushing system. On one hand, the utility model provides an efficient demisting device, the demisting device comprises a baffle plate demister, a first-stage cyclone demister and a second-stage cyclone demister, and the baffle plate demister, the first-stage cyclone demister and the second-stage cyclone demister are sequentially arranged along a wet desulphurization absorption tower from bottom to top; the inclination angle of a blade of the first-stage cyclone demister is 30-42 degrees, and the inclination angle of a blade of the second-stage cyclone demister is 44-52 degrees; the distance between the upper edge of the baffle plate demister and the lower edge of the first-stage cyclone demister is not less than 1000mm, and the distance between the upper edge of the first-stage cyclone demister and the lower edge of the second-stage cyclone demister is not less than 1000mm. On the other hand, the utility model further designs a demister flushing system for the efficient demisting device. According to the application, liquid drops in flue gas can be effectively captured, the demisting efficiency is relatively high, and a blockage fault is not easy to occur.

Description

Technical Field

[0001] The present application relates to the technical field of desulfurization equipment, and in particular to a high-efficiency demisting device and a demisting device flushing system. Background Art

[0002] At present, most coal-fired power units in my country use wet desulfurization technology. Limestone wet desulfurization technology is relatively mature and has the characteristics of low cost and good effect. Limestone wet desulfurization technology uses lime or limestone slurry to absorb sulfur dioxide in flue gas in an absorption tower to obtain a mixture of calcium sulfite and calcium sulfate, then introduces air to oxidize calcium sulfite, and finally refines the obtained calcium sulfate into (gypsum) desulfurization process. As my country has imposed more stringent requirements on the emission limits of pollutants such as PM, the PM content of flue gas after wet desulfurization has been increased. 2.5 The control of is also receiving increasing attention.

[0003] Existing technology for PM in flue gas after wet desulfurization 2.5 The components contained in the flue gas were analyzed in detail, and the main components are gypsum, limestone and fly ash, of which the total content of gypsum and limestone exceeds 40%. The gypsum and limestone particles contained in the flue gas are mainly formed by the fine droplets formed during the spraying of the desulfurization slurry during the limestone wet desulfurization process, mixed into the flue gas, escaped from the desulfurization tower, and were dehydrated by the high temperature of the flue gas during this process.

[0004] Wet desulfurization is widely used in coal-fired power plants. The demister in the absorption tower is an important component of the wet desulfurization device. The demister is usually installed at the top of the desulfurization tower. Its main function is to capture the droplets mixed in the smoke layer after flue gas desulfurization purification to protect the connecting pipes and parts in the desulfurization system from droplet pollution and corrosion, while reducing PM 2.5 To reduce PM 2.5 In order to reduce the emission of flue gas, most of the existing wet flue gas desulfurization equipment adopts a composite demisting system composed of two or three stages of demisters to capture as many droplets as possible in the flue gas. The demisting systems that are currently used more are generally of the following types: the first type is a demisting system composed of a tubular demister and a baffle demister, the second type is a demisting system composed of a multi-stage baffle demister, and the third type is a demisting system composed of a baffle demister and a wire mesh demister.

[0005] However, the above-mentioned demisting systems all have certain defects. Demisting systems with higher demisting efficiency, such as systems containing wire mesh demisters and systems using multi-stage dense baffles, are prone to clogging problems; while demisting systems that are not prone to clogging have less than ideal demisting efficiency and a relatively high droplet escape rate. Summary of the invention

[0006] In order to solve at least one of the above technical problems, a demisting system is developed which can effectively capture droplets in flue gas, has high demisting efficiency, and is not prone to blockage failure. The present application provides a high-efficiency demisting device and a demister flushing system.

[0007] The present application provides a high-efficiency defogger, which comprises a baffle demister, a primary cyclone demister and a secondary cyclone demister, wherein the baffle demister, the primary cyclone demister and the secondary cyclone demister are arranged in sequence from bottom to top along a wet desulfurization absorption tower; the blade inclination angle of the primary cyclone demister is 34° to 42°, and the blade inclination angle of the secondary cyclone demister is 46° to 52°; the distance between the upper edge of the baffle demister and the lower edge of the primary cyclone demister is not less than 1000 mm, and the distance between the upper edge of the primary cyclone demister and the lower edge of the secondary cyclone demister is not less than 1000 mm.

[0008] Optionally, the plate spacing L of the baffle demister is 25 to 35 mm.

[0009] Optionally, the folding angle θ of the baffle demister is 110° to 130°.

[0010] Optionally, the number of blades of the first-stage cyclone demister is 16 to 18.

[0011] Optionally, the number of blades of the secondary cyclone demister is 16 to 18.

[0012] Optionally, the blade inclination angle of the first-stage cyclone demister is 37° to 39°, the blade inclination angle of the second-stage cyclone demister is 49° to 51°, and the distance between the upper edge of the first-stage cyclone demister and the lower edge of the second-stage cyclone demister is 1080 to 1160 mm.

[0013] Further optionally, the distance between the upper edge of the baffle demister and the lower edge of the first-stage cyclone demister is 1100-1200 mm.

[0014] The present application also provides a demister flushing system, which is specially used for the above-mentioned high-efficiency demister, and the flushing system includes a flushing water supply device, and also includes a baffle flushing pipe group and a swirl plate flushing pipe group; the baffle flushing pipe group includes a central flushing straight pipe, which is arranged directly above the baffle demister, and the baffle demister is divided into two parts along the central flushing straight pipe, and the baffle flushing pipe group also includes four "F"-shaped flushing pipes, which are evenly arranged directly above the four quadrants formed by the two equally divided parts of the baffle demister; the swirl plate flushing pipe group includes an inner annular flushing pipe and an outer annular flushing pipe, and the inner annular flushing pipe and the outer annular flushing pipe are each arranged directly above the first-stage swirl demister and the second-stage swirl demister.

[0015] Optionally, the distance between the baffle plate flushing pipe group and the baffle plate demister is 600-650 mm, and the distance between the cyclone plate flushing pipe group and the corresponding first-stage cyclone demister or second-stage cyclone demister is 600-650 mm.

[0016] Optionally, the flushing pipes of the baffle plate flushing pipe group and the swirl plate flushing pipe group are provided with a plurality of flushing nozzles, which are evenly arranged along the bottom and both sides of the flushing pipes to form a spray fan of 100° to 120°.

[0017] In summary, the present invention includes at least one of the following beneficial technical effects:

[0018] 1. The present application adopts a primary baffle demister and a two-stage cyclone demister to form a demister. By designing the blade inclination angle and spacing of the two-stage cyclone demister, as well as the spacing design of the baffle demister and the cyclone demister, the demister can effectively improve the capture rate of droplets, thereby making the demister have a higher demisting efficiency. In addition, the design of the structural parameters of the cyclone demister of the present application can reduce the collision rate of droplets in the flue gas, which is conducive to the collision and coalescence of droplets, and can effectively reduce PM. 2.5 emissions.

[0019] 2. The present application adopts a design of a baffle demister in combination with a two-stage cyclone demister, and performs specific optimization design on the structural parameters of the cyclone demister, so that the demister device of the present application has a relatively lower wind resistance, which can increase the airflow velocity of the flue gas through the demister device, thereby reducing the occurrence rate of blockage failure of the demister device.

[0020] 3. The defogger flushing system of the present application adopts a specific pipeline structure design, which can effectively improve the coverage rate of the flushing pipeline on each defogger of the defogger device; at the same time, the pipeline structure design of the present application can ensure that the flushing water pressure of each flushing pipe is high, which can effectively improve the flushing effect and effectively avoid blockage failure of the defogger device. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the assembly structure of the high-efficiency demisting device of this application;

[0022] Figure 2 This is a schematic diagram of the structure of the baffle of the baffle demister of the present application;

[0023] Figure 3 This is a schematic diagram of the structure of the baffle flushing pipe group of this application;

[0024] Figure 4 This is a schematic diagram of the structure of the swirl plate flushing pipe group of this application;

[0025] Figure 5 This is a schematic diagram of the cross-sectional structure of the central flushing straight pipe of this application;

[0026] In the figure: 1. baffle demister; 2. primary cyclone demister; 3. secondary cyclone demister; 4. wet desulfurization absorption tower; 41. flue gas inlet; 42. flue gas outlet; 5. flushing water supply device; 6. pressure monitor; 7. center flushing straight pipe; 71. center flushing straight pipe flushing nozzle; 8. "F" shaped flushing pipe; 9. inner annular flushing pipe; 10. outer annular flushing pipe. DETAILED DESCRIPTION

[0027] The present application is further described in detail below with reference to the accompanying drawings and embodiments.

[0028] like Figure 1 As shown, the present application designs a high-efficiency demisting device, including a baffle demister 1, a primary cyclone demister 2 and a secondary cyclone demister 3, wherein the baffle demister 1, the primary cyclone demister 2 and the secondary cyclone demister 3 are arranged in sequence from bottom to top along the wet desulfurization absorption tower 4. Flue gas enters through the flue gas inlet 41 of the wet desulfurization absorption tower 4, and after being sprayed and desulfurized by the spray device, the flue gas carrying the spray droplets is sequentially demisted by the baffle demister 1, the primary cyclone demister 2 and the secondary cyclone demister 3, and then discharged through the flue gas outlet 42.

[0029] The blade inclination angle of the first-level cyclone demister 2 of the present application is 34°~42°, and the blade inclination angle of the second-level cyclone demister 3 is 46°~52°; the distance between the upper edge of the baffle demister 1 and the lower edge of the first-level cyclone demister 2 is not less than 1000mm, and the distance between the upper edge of the first-level cyclone demister 2 and the lower edge of the second-level cyclone demister 3 is not less than 1000mm.

[0030] The present application also designs a defogger flushing system for the high-efficiency defogger of the present application, and the flushing system includes a flushing water supply device 5, and also includes a baffle flushing pipe group and a cyclone flushing pipe group. The baffle flushing pipe group and the cyclone flushing pipe group are respectively used for flushing the baffle defogger 1, and flushing the primary cyclone defogger 2 and the secondary cyclone defogger 3 to avoid clogging of the defogger. The flushing water supply device 5 is used to supply flushing water to the baffle flushing pipe group and the cyclone flushing pipe group.

[0031] like Figure 3 As shown, the baffle flushing pipe group of the present application includes a central flushing straight pipe 7, which is arranged directly above the baffle demister 1. From a top-down perspective, the baffle demister 1 is equally divided into two parts along the central flushing straight pipe 7. From a top-down perspective, the circular baffle demister 1 is equally divided into two parts, each of which is divided into two quadrants, forming exactly four quadrants. The baffle flushing pipe group also includes four "F"-shaped flushing pipes 8, which are evenly arranged directly above the above-mentioned four quadrants.

[0032] like Figure 4 As shown, the cyclone plate flushing pipe group of the present application includes an inner annular flushing pipe 9 and an outer annular flushing pipe 10. The inner annular flushing pipe 9 and the outer annular flushing pipe 10 of the present application are arranged one set each directly above the primary cyclone demister 2 and the secondary cyclone demister 3.

[0033] Preferably, in order to improve the flushing effect, each flushing pipe of the baffle flushing pipe group and the swirl plate flushing pipe group of the present application is provided with a plurality of flushing nozzles. The flushing nozzles are evenly arranged along the bottom and both sides of the flushing pipe to form a spray fan of 100° to 120°.

[0034] like Figure 5 As shown, taking the central flushing straight pipe 7 of the present application as an example, a plurality of central flushing straight pipe flushing nozzles 71 are evenly arranged along the bottom and both sides thereof to form a spray fan of 100° to 120°.

[0035] The following are examples of the present application:

[0036] Example 1

[0037] The high-efficiency demisting device of this embodiment comprises a baffle demister 1, a primary cyclone demister 2 and a secondary cyclone demister 3 which are arranged in sequence from bottom to top along a wet desulfurization absorption tower 4.

[0038] In the baffle demister 1 of this embodiment, the baffle thickness is 3 mm, the plate spacing L is 25 mm, and the folding angle θ is 130°.

[0039] The primary cyclone demister 2 of this embodiment has 16 blades, a blade thickness of 3 mm, and a blade inclination angle of 34°.

[0040] The secondary cyclone demister 3 of this embodiment has 18 blades, a blade thickness of 3 mm, and a blade inclination angle of 52°.

[0041] In this embodiment, the distance between the upper edge of the baffle demister 1 and the lower edge of the primary cyclone demister 2 is 1000 mm, and the distance between the upper edge of the primary cyclone demister 2 and the lower edge of the secondary cyclone demister 3 is 1000 mm.

[0042] This embodiment is also equipped with a demister flushing system designed in the present application, and the flushing nozzles of each flushing pipe form a 120° spray fan.

[0043] In this embodiment, the distance between the baffle plate flushing pipe group and the baffle plate demister 1 is 600 mm, and the distance between the cyclone plate flushing pipe group and the corresponding first-stage cyclone demister 2 or second-stage cyclone demister 3 is also 600 mm.

[0044] In the swirl plate flushing pipe group of this embodiment, the sum of the radius of the inner annular flushing pipe 9 and the distance between the outer annular flushing pipe 10 and the inner wall of the wet desulfurization absorption tower 4 is equal to the distance between the inner annular flushing pipe 9 and the outer annular flushing pipe 10.

[0045] Example 2

[0046] The structure of this embodiment is basically similar to that of Embodiment 1, except for the structural parameters of the demisting device.

[0047] In the baffle demister 1 of this embodiment, the baffle thickness is 3 mm, the plate spacing L is 30 mm, and the folding angle θ is 120°.

[0048] The primary cyclone demister 2 of this embodiment has 18 blades, a blade thickness of 3 mm, and a blade inclination angle of 37°.

[0049] The secondary cyclone demister 3 of this embodiment has 18 blades, a blade thickness of 3 mm, and a blade inclination angle of 49°.

[0050] In this embodiment, the distance between the upper edge of the baffle demister 1 and the lower edge of the primary cyclone demister 2 is 1080 mm, and the distance between the upper edge of the primary cyclone demister 2 and the lower edge of the secondary cyclone demister 3 is 1100 mm.

[0051] Example 3

[0052] The structure of this embodiment is basically similar to that of Embodiment 1, except for the structural parameters of the demisting device.

[0053] In the baffle demister 1 of this embodiment, the baffle thickness is 3 mm, the plate spacing L is 35 mm, and the bending angle θ is 110°.

[0054] The primary cyclone demister 2 of this embodiment has 17 blades, a blade thickness of 3 mm, and a blade inclination angle of 39°.

[0055] The secondary cyclone demister 3 of this embodiment has 18 blades, a blade thickness of 3 mm, and a blade inclination angle of 51°.

[0056] In this embodiment, the distance between the upper edge of the baffle demister 1 and the lower edge of the primary cyclone demister 2 is 1160 mm, and the distance between the upper edge of the primary cyclone demister 2 and the lower edge of the secondary cyclone demister 3 is 1200 mm.

[0057] Example 4

[0058] The structure of this embodiment is basically similar to that of Embodiment 1, except for the structural parameters of the demisting device.

[0059] In the baffle demister 1 of this embodiment, the baffle thickness is 3 mm, the plate spacing L is 30 mm, and the folding angle θ is 120°.

[0060] The primary cyclone demister 2 of this embodiment has 17 blades, a blade thickness of 3 mm, and a blade inclination angle of 38.6°.

[0061] The secondary cyclone demister 3 of this embodiment has 18 blades, a blade thickness of 3 mm, and a blade inclination angle of 50.4°.

[0062] In this embodiment, the distance between the upper edge of the baffle demister 1 and the lower edge of the primary cyclone demister 2 is 1100 mm, and the distance between the upper edge of the primary cyclone demister 2 and the lower edge of the secondary cyclone demister 3 is 1160 mm.

[0063] In Examples 1 to 4 of the present application, pressure monitors 6 can be installed in the wet flue gas desulfurization absorption tower 4, below the baffle demister 1, between the baffle demister 1 and the primary cyclone demister 2, between the primary cyclone demister 2 and the secondary cyclone demister 3, and above the secondary cyclone demister 3, to monitor the flow rate and pressure of the flue gas to determine whether a blockage fault occurs.

[0064] The performance of the defogger devices and defogger flushing systems of Examples 1 to 4 of the present application was tested, and the specific testing process is as follows.

[0065] The demister devices and demister flushing systems of Examples 1 to 4 were respectively installed on the limestone-gypsum wet desulfurization absorption tower of a 630MW coal-fired unit and operated normally for 30 days.

[0066] Optical detection equipment for detecting droplet content is installed directly below and above the defogger to detect and calculate the defogger efficiency, and the reduction rate of droplets after defogger treatment by the defogger is taken as the defogger efficiency; the pressure difference between the defoggers of each stage of the defogger during operation is monitored by the pressure monitor 6 to determine whether the defogger is blocked during operation. The pressure difference is often used to open the flushing system for flushing, and the failure to eliminate the pressure difference by flushing is often used as an indicator of the occurrence of a blockage.

[0067] The obtained test data are shown in Table 1 below.

[0068] Table 1 Performance test data of Examples 1 to 4

[0069] Demisting efficiency (%) Blockage Occurrence Example 1 96.6 none Example 2 97.1 none Example 3 97.2 none Example 4 97.5 none

[0070] It can be seen from the data in Table 1 that the high-efficiency demisting devices of Examples 1 to 4 of the present application have a high demisting efficiency, and the demisting efficiency in actual application exceeds 96%. In addition, it can also be seen from the data in Table 1 that the high-efficiency demisting device of the present application, in conjunction with the demister flushing system of the present application, has no clogging failure after continuous operation for 30 days, which shows that the failure rate of the present application is also low.

[0071] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A high-efficiency demisting device, characterized in that: The demisting device comprises a baffle demister (1), a primary cyclone demister (2) and a secondary cyclone demister (3), wherein the baffle demister (1), the primary cyclone demister (2) and the secondary cyclone demister (3) are arranged in sequence from bottom to top along a wet desulfurization absorption tower (4); the blade inclination angle of the primary cyclone demister (2) is 34° to 42°, and the blade inclination angle of the secondary cyclone demister (3) is 46° to 52°; the distance between the upper edge of the baffle demister (1) and the lower edge of the primary cyclone demister (2) is not less than 1000 mm, and the distance between the upper edge of the primary cyclone demister (2) and the lower edge of the secondary cyclone demister (3) is not less than 1000 mm.

2. The high-efficiency demisting device according to claim 1, characterized in that: The plate spacing L of the baffle demister (1) is 25 to 35 mm.

3. The high-efficiency demisting device according to claim 1, characterized in that: The folding angle θ of the baffle demister (1) is 110° to 130°.

4. The high-efficiency demisting device according to claim 1, characterized in that: The number of blades of the primary cyclone demister (2) is 16 to 18.

5. The high-efficiency demisting device according to claim 1, characterized in that: The number of blades of the secondary cyclone demister (3) is 16 to 18.

6. The high-efficiency demisting device according to claim 1, characterized in that: The blade inclination angle of the primary cyclone demister (2) is 37° to 39°, the blade inclination angle of the secondary cyclone demister (3) is 49° to 51°, and the distance between the upper edge of the primary cyclone demister (2) and the lower edge of the secondary cyclone demister (3) is 1080 to 1160 mm.

7. The high-efficiency demisting device according to claim 6, characterized in that: The distance between the upper edge of the baffle demister (1) and the lower edge of the primary cyclone demister (2) is 1100 to 1200 mm.

8. A demister flushing system, specifically used for the high-efficiency demister device according to any one of claims 1 to 7, characterized in that: The flushing system comprises a flushing water supply device (5), and also comprises a baffle flushing pipe group and a cyclone flushing pipe group; the baffle flushing pipe group comprises a central flushing straight pipe (7), which is arranged directly above the baffle demister (1), and the baffle demister (1) is equally divided into two parts along the central flushing straight pipe (7); the baffle flushing pipe group also comprises four "F"-shaped flushing pipes (8), which are evenly arranged directly above the four quadrants formed by the two equally divided parts of the baffle demister (1); the cyclone flushing pipe group comprises an inner annular flushing pipe (9) and an outer annular flushing pipe (10), and each of the inner annular flushing pipe (9) and the outer annular flushing pipe (10) is arranged directly above the primary cyclone demister (2) and the secondary cyclone demister (3).

9. The demister flushing system according to claim 8, characterized in that: The distance between the baffle plate flushing pipe group and the baffle plate demister (1) is 600-650 mm, and the distance between the cyclone plate flushing pipe group and the corresponding first-stage cyclone demister (2) or second-stage cyclone demister (3) is 600-650 mm.

10. The demister flushing system according to claim 8, characterized in that: The flushing pipes of the baffle plate flushing pipe group and the swirl plate flushing pipe group are provided with a plurality of flushing nozzles, which are evenly arranged along the bottom and both sides of the flushing pipes to form a spray fan of 100° to 120°.

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