Corrosion prevention method of flue for discharging wet desulphurization flue gas

Abstract

The invention relates to the technical field of wet desulphurization flue gas treatment, and discloses an anti-corrosion method of a flue for discharging wet desulphurization flue gas, which comprises the following steps: step 1, prefabricating a glass fiber reinforced plastic lining; step 2, prefabricating a connecting component and a supporting component; 3, the glass fiber reinforced plastic lining is installed in the flue in a segmented mode; 4, the glass fiber reinforced plastic lining is connected with the flue through a connecting part; meanwhile, the supporting component is installed in the glass fiber reinforced plastic lining; 5, a clean flue inlet for receiving flue gas is formed, and an acid discharge system is arranged; and step 6, carrying out anti-corrosion treatment on the glass fiber reinforced plastic lining, the connecting part, the supporting part, the clean flue inlet and the acid discharge system. According to the invention, the glass reinforced plastic plates are spliced to form the glass reinforced plastic protective lining with a closed structure, and the glass reinforced plastic protective lining is arranged in the flue for corrosion prevention, so that a corrosive medium in flue gas subjected to wet desulfurization can be effectively prevented from permeating into the flue, and the flue is effectively protected from corrosion; and construction is convenient, the construction period is short, and the service life is long.

Description

Technical Field

[0001] The invention relates to the technical field of wet desulfurization flue gas treatment, and in particular to an anti-corrosion method for a flue used for discharging wet desulfurization flue gas. Background Art

[0002] Flue gas wet desulfurization technology represented by limestone-gypsum is widely used in the flue gas emission treatment process of thermal power plants because of its high removal efficiency of sulfur dioxide in flue gas and low operating cost. However, the flue gas contains a lot of water after wet desulfurization, which has a certain impact on flue gas emissions. The temperature of the flue gas before wet desulfurization is about 130-150℃, and the temperature drops to 45-55℃ after desulfurization; the water vapor in the flue gas is in a saturated state, and the flue gas coming out of the desulfurization device inevitably carries droplets. Although the removal efficiency of sulfur dioxide can reach 99.3% during the wet desulfurization process, some droplets are still not removed. At the same time, the removal efficiency of sulfur trioxide in the flue gas by wet desulfurization is very low. In this way, in the process of flue gas entering the flue for emission, as the temperature decreases, the flue gas continues to condense and condense on the inner wall of the flue, forming a highly corrosive dilute sulfuric acid solution, causing corrosion to the inner wall of the flue. At the same time, the high-speed flow of flue gas scours and wears the inner wall of the flue, which further accelerates the corrosion rate of the inner wall of the flue, and puts higher requirements on the protection and anti-corrosion of the flue.

[0003] The commonly used flue anti-corrosion methods are as follows: a. Lining with flake resin; b. Applying anti-corrosion paint (OM paint, etc.); c. Using ceramic lining tiles; d. Using fluorine and silicone rubber anti-corrosion materials. However, although the lining flake resin solution has good anti-corrosion performance, it has a relatively low adaptability temperature, a long on-site construction period, high requirements for the on-site construction environment, and a short service life; although the anti-corrosion paint solution has a fast construction speed, it has poor anti-corrosion performance and a short service life; ceramic lining tiles need to be bonded to the inner wall of the flue through organic anti-corrosion adhesives. There are many factors affecting the anti-corrosion quality, and the on-site construction requirements are very high. The defects of local anti-corrosion will lead to the failure of the entire anti-corrosion solution, and the lining bricks have a large water absorption rate and the quality of the gaps between the lining bricks is difficult to guarantee; the fluorine and silicone rubber anti-corrosion solutions have more processes, high requirements for the on-site construction environment, and difficult to control the construction quality. It is difficult to handle key parts such as flue internal corners, expansion joints, and drainage holes. Therefore, an effective and economically reasonable flue anti-corrosion technology is needed. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a method for anti-corrosion of a flue for discharging wet desulfurization flue gas. The method comprises assembling glass fiber reinforced plastic plates to form a structurally closed glass fiber reinforced plastic protective lining and arranging the lining in the flue to prevent the flue from being corroded. The method can effectively prevent the corrosive medium in the flue gas after wet desulfurization from penetrating into the flue, and effectively protect the flue from corrosion. The method is convenient to construct, has a short construction period and a long service life.

[0005] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: an anti-corrosion method for a flue for discharging wet desulfurization flue gas, comprising the following steps: step 1, prefabricating a glass fiber reinforced plastic lining; step 2, prefabricating components for connecting the glass fiber reinforced plastic lining and the flue, and prefabricating supporting components for the glass fiber reinforced plastic lining; step 3, installing the glass fiber reinforced plastic lining in sections into the flue; step 4, using the connecting components prefabricated in step 2 to connect the glass fiber reinforced plastic lining and the flue to fix the two; at the same time, installing the supporting components prefabricated in step 2 inside the glass fiber reinforced plastic lining so that the supporting components are close to the inner wall of the glass fiber reinforced plastic lining; step 5, opening a clean flue inlet for receiving flue gas and setting an acid discharge system; step 6, performing anti-corrosion treatment on the glass fiber reinforced plastic lining, connecting components, supporting components, clean flue inlet and acid discharge system.

[0006] Furthermore, the process of prefabricating the FRP lining in step 1 is: first lay a layer of 300g / ㎡ glass fiber chopped mat, then brush a layer of resin glue on it and ensure that the glass fiber chopped mat is soaked with the resin glue, then lay a layer of 600g / ㎡ glass fiber cloth on the glass fiber chopped mat, and so on continuously and alternately lay four layers of glass fiber chopped mat and three layers of glass fiber cloth.

[0007] Furthermore, the overall thickness of the four layers of glass fiber chopped strand mat and the three layers of glass fiber cloth is not less than 6.5 mm, and they need to be naturally solidified for more than 12 hours after laying; the weight of the resin glue accounts for not less than 60% of the total weight of the FRP lining; the connecting components in step 2 include stainless steel expansion bolts, and the FRP lining in step 4 is fixed to the flue through the connecting components; the supporting components include a door frame and angle steel, the door frame is set close to the side wall and top wall of the FRP lining, and the angle steel is installed between adjacent door frames; a cross-shaped support tube is set in the door frame.

[0008] Furthermore, before installing the FRP lining in step 3, a filling layer is first set on the inner wall of the flue to deal with the gaps in the corners. The specific method is: fill the gaps in the inner wall of the flue with putty formed by mixing resin and talcum powder to ensure that the inner wall of the flue is flat, and the thickness of the filling layer is not less than 13mm.

[0009] Furthermore, after the installation of the FRP lining is completed, a bottom plate reinforcement layer is set on the bottom plate surface of the FRP lining; the construction process of the bottom plate reinforcement layer is as follows: first apply a layer of resin glue on the upper surface of the FRP lining bottom plate, and then lay a layer of 600g / ㎡ and 0.7mm thick glass fiber cloth, compact it tightly, and then brush a layer of resin glue on it, and then lay a layer of 300g / ㎡ and 0.75mm thick glass fiber chopped mat, and then brush a layer of resin glue on it to ensure that the glass fiber chopped mat is soaked with resin glue, and then stick a layer of 600g / ㎡ and 0.7mm thick glass fiber cloth, the overall thickness is not less than 3mm, and the bottom plate reinforcement layer needs to be naturally solidified for more than 12 hours after laying. The weight of the resin glue accounts for not less than 60% of the total weight of the bottom plate reinforcement layer.

[0010] Furthermore, the acid discharge system includes an acid discharge port and an acid discharge main pipeline connected to each acid discharge port for receiving the acid liquid from each acid discharge port; the acid discharge port is arranged at the lowest point of each section of the flue, and the diameter of the acid discharge port is 200mm.

[0011] Furthermore, the anti-corrosion treatment method in step 6 is: hand-laying FRP on the surfaces of the FRP lining, connecting parts, supporting parts, clean flue inlet and various parts of the acid discharge system.

[0012] Furthermore, the connecting components in step 2 include a fixing box pre-buried in the flue, a positioning rod inserted into and fixed in the fixing box from the inside of the fiberglass lining, and a sealing part connected to the end of the positioning rod for corrosion protection; a first groove is opened on the inner wall of the flue toward the fixing box, and a second groove connected to the fixing box is opened inside the flue from the bottom of the first groove toward the fixing box; the positioning rod is inserted into the second groove, and a limiting ring capable of being sleeved with the positioning rod is provided on the side of the fixing box close to the positioning rod, and a swing rod rotatably connected to the limiting ring is provided on the side of the limiting ring away from the positioning rod, a positioning part is provided at the end of the swing rod, and the positioning rod is correspondingly provided with a groove capable of accommodating the positioning part; when the positioning rod is inserted into the fixing box, the straight line connecting the groove and the positioning part is parallel to the axial center line of the positioning rod.

[0013] Furthermore, the rocker arm is located at the bottom of the limiting ring, and a support sheet is provided at the limiting ring corresponding to the positioning part and below the positioning part, and an elastic rubber block that can resist the positioning part is connected to the side of the support sheet close to the positioning part; a chamfer is provided at one end of the positioning rod close to the fixed box for facilitating pushing the positioning rod to move toward the edge of the limiting ring, and a slope is provided on the side of the positioning part close to the positioning rod for facilitating being pushed toward the edge of the limiting ring by the positioning rod; the sealing part includes an anti-corrosion disk connected to one end of the positioning rod and placed inside the first trough; a connection reinforcement part is provided on the outer side of the anti-corrosion disk; and a sealing layer is filled between the outer side of the anti-corrosion disk and the side wall of the first trough.

[0014] Furthermore, the connection reinforcement part is a convex particle and / or a concave depression; the anti-corrosion disk is made of unsaturated polyester resin cured; the sealing layer is made of an expandable anti-corrosion coating with a curing agent added or an epoxy resin coating with an expander and a curing agent added.

[0015] The beneficial effects of the present invention are:

[0016] 1. By assembling FRP plates into a closed FRP protective lining and setting it in the flue to prevent the flue from corrosion, it can effectively prevent the corrosive medium in the flue gas after wet desulfurization from penetrating into the flue, and effectively protect the flue from corrosion; it is convenient to construct, with a short construction period and a long service life; using this method for the anti-corrosion of the inner wall of the flue can solve the problems of poor mechanical strength, poor anti-corrosion performance and short service life that are common in other anti-corrosion technologies. This anti-corrosion method makes full use of the characteristics of FRP materials such as light weight, high strength, good chemical corrosion resistance and strong design performance. Through pultrusion and compression molding, FRP plates with plate rib structure are continuously mass-produced in the production workshop, ensuring the production quality of FRP plate products, improving the efficiency of on-site anti-corrosion construction, avoiding heavy on-site manufacturing work, greatly shortening the on-site flue anti-corrosion construction period, ensuring the quality of the anti-corrosion project, and completely solving the problem of leakage in wet flue operation.

[0017] 2. By using a fixing box, a positioning rod, a swing rod, a positioning part and a groove to form a connecting component, the stability of the connection between the FRP lining and the flue is improved. The construction process does not need to be increased much, and the support measures for the FRP lining are reduced.

[0018] 3. By using unsaturated polyester resin to cure and make the anti-corrosion disc, and using an expandable anti-corrosion coating or an epoxy resin coating with an expander and a curing agent as the sealing layer 16, not only the connecting parts have good anti-corrosion performance, but also have a certain hardness, which can be adjusted as needed, while reducing other anti-corrosion measures, making the construction more convenient and faster. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0020] Figure 2 It is a front view structural schematic diagram of the present invention;

[0021] Figure 3 It is a schematic diagram of the fixing structure of the glass fiber reinforced plastic lining and the flue of the present invention;

[0022] Figure 4 For the present invention Figure 3 The enlarged structural diagram at A in the middle;

[0023] Figure 5 is a cross-sectional schematic diagram of a second connecting component of the present invention;

[0024] Figure 6 is an overall schematic diagram of a second connecting component of the present invention;

[0025] Figure 7 This is a schematic diagram of the structure of the second connecting component of the present invention, in which the lower part is flipped to the upper part;

[0026] Figure 8 This is a schematic diagram of a second positioning rod of the present invention.

[0027] In the figure: 1. flue; 2. FRP lining; 3. bottom plate reinforcement layer; 4. clean flue entrance; 5. acid discharge port; 6. acid discharge main pipe; 7. door frame; 8. angle steel; 9. filling layer; 10. first trough; 11. second trough; 12. positioning rod; 13. anti-corrosion disk; 14. fixing box; 15. limiting ring; 16. sealing layer; 17. connection reinforcement part; 18. groove; 19. fixed shaft; 20. rocker arm; 21. positioning part; 22. support sheet; 23. elastic rubber block; 24. inclined surface; 25. chamfer. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present invention are described clearly and completely below in conjunction with the accompanying drawings and specific embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0029] The directional terms mentioned in the present invention, such as "up", "down", "front", "back", "left", "right", "inside", "outside", "side", "top" and "bottom", are only for reference to the orientation of the drawings. The directional terms used are used to illustrate and understand the present invention, but not to limit the present invention.

[0030] Embodiment 1:

[0031] like Figure 1-Figure 8 As shown, a method for anti-corrosion of a flue for discharging wet desulfurization flue gas comprises the following steps: step 1, prefabricating a glass fiber reinforced plastic lining 2; step 2, prefabricating a connecting component between the glass fiber reinforced plastic lining 2 and the flue 1, and prefabricating a supporting component of the glass fiber reinforced plastic lining 2; step 3, installing the glass fiber reinforced plastic lining 2 in sections into the flue 1; step 4, connecting the glass fiber reinforced plastic lining 2 and the flue 1 using the connecting component prefabricated in step 2 to fix the two; at the same time, installing the supporting component prefabricated in step 2 inside the glass fiber reinforced plastic lining 2 so that the supporting component is close to the inner wall of the glass fiber reinforced plastic lining 2; step 5, opening a clean flue inlet 4 for receiving flue gas and setting an acid discharge system; step 6, performing anti-corrosion treatment on the glass fiber reinforced plastic lining 2, the connecting component, the supporting component, the clean flue inlet 4 and the acid discharge system.

[0032] The process of prefabricating the FRP lining 2 in step 1 is as follows: first lay a layer of 300g / ㎡ glass fiber chopped mat, then brush a layer of resin glue on it and ensure that the glass fiber chopped mat is soaked with the resin glue, then lay a layer of 600g / ㎡ glass fiber cloth on the glass fiber chopped mat, and so on continuously and alternately lay four layers of glass fiber chopped mat and three layers of glass fiber cloth.

[0033] The overall thickness of the four layers of glass fiber chopped strand mat and the three layers of glass fiber cloth is not less than 6.5 mm, and it needs to solidify naturally for more than 12 hours after laying. The weight of the resin glue accounts for not less than 60% of the total weight of the FRP lining 2. The connecting components in step 2 include stainless steel expansion bolts, and the FRP lining 2 in step 4 is fixed to the flue 1 through the connecting components. The supporting components include a door frame 7 and an angle steel 8. The door frame 7 is arranged close to the side wall and the top wall of the FRP lining 2, and the angle steel 8 is installed between adjacent door frames 7. A cross-shaped support tube is arranged in the door frame 7.

[0034] Before installing the fiberglass lining 2 in step 3, a filling layer 9 is first set on the inner wall of the flue 1 to deal with the gaps in the corners. The specific method is: fill the gaps in the inner wall of the flue 1 with putty formed by mixing resin and talcum powder to ensure that the inner wall of the flue 1 is flat, and the thickness of the filling layer 9 is not less than 13mm.

[0035] After the installation of the FRP lining 2 is completed, a bottom plate reinforcement layer 3 is set on the bottom plate surface of the FRP lining 2; the construction process of the bottom plate reinforcement layer 3 is as follows: first, a layer of resin glue is applied on the upper surface of the bottom plate of the FRP lining 2, and then a layer of 600g / ㎡ and 0.7mm thick glass fiber cloth is laid, pressed tightly, and then a layer of resin glue is applied thereon, and then a layer of 300g / ㎡ and 0.75mm thick glass fiber chopped mat is laid, and then a layer of resin glue is applied thereon to ensure that the glass fiber chopped mat is soaked with the resin glue, and then a layer of 600g / ㎡ and 0.7mm thick glass fiber cloth is laid, and the overall thickness is not less than 3mm. After the bottom plate reinforcement layer 3 is laid, it needs to be naturally solidified for more than 12 hours, and the weight of the resin glue accounts for not less than 60% of the total weight of the bottom plate reinforcement layer 3.

[0036] The clean flue inlet 4 is connected to one end of the clean flue; the acid discharge system includes an acid discharge port 5 and an acid discharge main pipe 6 connected to each acid discharge port 5 for receiving the acid liquid from each acid discharge port 5; the acid discharge port 5 is arranged at the lowest point of each section of the flue 1, and the diameter of the acid discharge port 5 is 200 mm.

[0037] The anti-corrosion treatment method in step 6 is: hand-laying FRP on the surfaces of the FRP lining 2, connecting parts, supporting parts, clean flue inlet 4 and various parts of the acid discharge system.

[0038] The inner surface treatment process of the FRP lining 2 is as follows: mechanical grinding to remove burrs, glue flow and dust on the surface of the FRP plate, increase the surface roughness, apply a layer of glue on the base surface of the structural layer, and randomly line it with a layer of 300g / ㎡ glass fiber chopped strands mat; then brush a layer of resin glue on it and ensure that the glass fiber chopped strands mat is soaked with the resin glue; then lay two layers of 300g / ㎡ glass fiber chopped strands mat in the same way, and finally lay a layer of 50g / ㎡ glass fiber surface felt, with an overall thickness of not less than 3mm and a resin glue content of more than 85%; after completion, naturally cure for more than 24 hours, and apply surface glue after curing; silicon carbide wear-resistant agent is added to this layer of resin glue, and the ratio is resin glue: silicon carbide = 10:1.

[0039] Anti-corrosion treatment of expansion bolts: First, grind the area around the nut, then use resin cement to make a smooth transition to the nut position, and apply hand-layup anti-corrosion layering to the nut area. Fill the area around the nut with resin cement before laying the glass fiber chopped strand mat.

[0040] The angle steel 8, the door frame 7 and the supporting pipe are anti-corrosive with hand-laid fiberglass, and the overall thickness is not less than 6mm; the acid discharge pipe is connected to the acid discharge port 5 through hand-laid fiberglass anti-corrosive.

[0041] The clean flue inlet 4 and the interface connecting the clean flue and the chimney are all constructed with hand-laid fiberglass laminated anti-corrosion. The construction process is: 1 layer of 300g / ㎡ chopped strand mat + 3 layers of 400g / ㎡ glass fiber cloth + 2 layers of 300g / ㎡ chopped strand mat, the cloth layer is 120mm wide, the felt layer is 150mm wide, the layer thickness is consistent with the flue slab, and the overlap width is not less than 500mm.

[0042] Embodiment 2:

[0043] Different from Example 1, the connecting component in step 2 includes a fixing box 14 pre-buried in the flue 1, a positioning rod 12 inserted into and fixed in the fixing box 14 from the inside of the glass fiber reinforced plastic lining 2, and a sealing part connected to the end of the positioning rod 12 for corrosion protection; a first sinking groove 10 is opened on the inner wall of the flue 1 toward the fixing box 14, and a second sinking groove 11 connected to the fixing box 14 is opened inside the flue 1 from the bottom of the first sinking groove 10 toward the fixing box 14; the positioning rod 12 is inserted into the second sinking groove 11, and a limiting ring 15 capable of being sleeved with the positioning rod 12 is provided on the side of the fixing box 14 close to the positioning rod 12, and a swing rod 20 rotatably connected to the limiting ring 15 is provided on the side of the limiting ring 15 away from the positioning rod 12, and a positioning part 21 is provided at the end of the swing rod 20, and a groove 18 capable of accommodating the positioning part 21 is correspondingly provided on the positioning rod 12; when the positioning rod 12 is inserted into the fixing box 14, the straight line connecting the groove 18 and the positioning part 21 is parallel to the axis line of the positioning rod 12.

[0044] The limiting ring 15 is fixedly connected with a fixed shaft 19 along the axial direction of the positioning rod 12. One end of the rocker arm 20 is rotatably connected to the fixed shaft 19, and the other end is provided with a positioning portion 21 near the center direction of the limiting ring 15. The vertical cross-section of the positioning portion 21 is trapezoidal, and the longer side of the trapezoid is located on the rocker arm 20 and the shorter side is first inserted into the groove 18, so that it is convenient for the positioning portion 21 to disengage from the groove 18 when the positioning rod 12 is rotated.

[0045] like Figure 7 and Figure 8 As shown, the swing rod 20 is located at the bottom of the limiting ring 15, so that the swing rod 20 will not have a tendency to rotate toward the inside of the limiting ring 15; the limiting ring 15 corresponds to the positioning portion 21 and is provided with a support sheet 22 below the positioning portion 21. The support sheet 22 is connected to an elastic rubber block 23 that can resist the positioning portion 21 on the side close to the positioning portion 21. The elastic rubber block 23 corresponds to the positioning portion 21 and gives it a certain supporting force to ensure that the positioning portion 21 will not easily escape from the groove 18. When the positioning rod 12 is rotated, the elastic rubber block 23 can be compressed to make the positioning portion 21 come out of the groove 18; thereby replacing the positioning rod 12 or the blocking portion; the end of the positioning rod 12 close to the fixing box 14 is provided with a chamfer 25 that is convenient for pushing the positioning rod 21 to move toward the edge of the limiting ring 15, and the side of the positioning portion 21 close to the positioning rod 12 is provided with an inclined surface 24 that is convenient for being pushed to the edge of the limiting ring 15 by the positioning rod 12.

[0046] The swing rod 20 can also be located on the upper part of the limiting ring 15. At this time, a coil spring is arranged on the outside of the fixed shaft 19. The inside of the coil spring is connected to the fixed shaft 19, and the outside is connected to the through hole of the fixed shaft 19 corresponding to the swing rod 20. The coil spring ensures that the swing rod 20 will not rotate toward the center of the limiting ring 15, and will not rotate easily, and can maintain a certain elasticity, so that the positioning part 21 can be inserted into the groove 18, and the positioning rod 12 can be rotated to make the positioning part 21 disengage from the groove 18 without too much force, or the coil spring is arranged according to the needs to control the force required for insertion and disengagement; the positions and supporting arrangements of these two types of swing rods 20 can prevent the positioning rod 12 from failing to be inserted into the fixed box 14; the blocking part includes an anti-corrosion disk 13 connected to one end of the positioning rod 12 and placed inside the first sink 10; a connection reinforcement part 17 is arranged on the outside of the anti-corrosion disk 13; a sealing layer 16 is filled between the outside of the anti-corrosion disk 13 and the side wall of the first sink 10.

[0047] The connection reinforcement part 17 is a convex particle and / or a concave depression; the shape is mostly irregular, the manufacturing precision requirement is low, it is easy to manufacture, and the friction force can also be improved; the anti-corrosion disk 13 is cured by unsaturated polyester resin; such as bisphenol A unsaturated polyester resin, the cost is low and the construction is convenient; bisphenol A unsaturated polyester resin has good acid, alkali and salt corrosion resistance, good temperature resistance, and convenient curing and construction process; it is particularly suitable for projects that require resistance to dilute sulfuric acid corrosion and strict cost control; in addition, it has a certain hardness after curing to ensure the connection strength; in order to increase the hardness, reinforcing materials such as glass fiber, quartz powder, etc. can be added to the mold; methyl ethyl ketone peroxide (MEKP) and the like can be used as a curing agent, and cobalt salts and the like can be used as accelerators, Accelerate curing; the sealing layer 16 adopts an intumescent anti-corrosion coating with a curing agent added or an epoxy resin coating with an intumescent agent and a curing agent added; the intumescent agent is phosphate, polyphosphate, borate, etc.; the curing agent is an amine curing agent, anhydride curing agent, etc.; because the temperature of the flue gas after treatment will not be too high, the use of the above materials as the sealing layer 16 can ensure both the anti-corrosion effect and the economic benefit; and there is no need to perform anti-corrosion treatment on the outside like expansion bolts; the expansion bolts use friction to connect the glass fiber reinforced plastic lining 2 and the flue. The present embodiment improves the stability of the connection by setting a fixing box 14 and a positioning rod 12, and correspondingly can reduce the connection or support of other parts; for example, reduce the setting of the door frame 7, increase the spacing between adjacent door frames 7, etc.

[0048] Working process: before setting the filling layer 9, first locate the position of the connecting parts, embed the fixing box 14, open a sink groove of a certain depth on the channel 1, install the fixing box 14 into the sink groove, and then fill it with concrete. However, the concrete must leave a passage leading to the middle hole of the limiting ring 15 after filling. At the same time, locate the position of the limiting ring 15, and then install the filling layer 9 and the FRP lining 2. After the installation is completed, punch holes according to the position of the located limiting ring 15; in order to prevent the fixing box 14 from being blocked, embed the fixing box 14 and leave a passage leading to the middle hole of the limiting ring 15, and then paste a patch covering the middle hole on the surface of the limiting ring 15, and ensure that the patch is easy to remove; after installing the FRP lining 2, The liner 2 starts to drill holes corresponding to the limit ring 15, and cleans the holes after drilling. After cleaning, the anti-corrosion disk 13 is connected to the positioning rod 12, which can be plugged in or sleeved. The plug-in or sleeve connection requires interference fit to ensure the connection strength; the anti-corrosion disk 13, the fixing box 14, the limit ring 15 and the components connected thereto are all prefabricated; the groove 18 of the positioning rod 12 corresponds to the position of the positioning part 21 that has been positioned before, and then inserted into the second sink trough 11, the positioning rod 12 pushes the positioning part 21 and the rocker rod 20 to the outside of the limit ring 15 until the positioning part 21 falls into the groove 18, and the positioning is completed. The positioning part 21 can be disengaged from the groove 18 by turning the positioning rod 12 forcefully; then fill the sealing layer 16 between the anti-corrosion disk 13 and the side wall of the first sink trough 10.

[0049] The above description is only used to illustrate the technical solution of the present invention rather than to limit it. Other modifications or equivalent substitutions made to the technical solution of the present invention by ordinary technicians in this field should be included in the scope of the claims of the present invention as long as they do not depart from the spirit and scope of the technical solution of the present invention.

Claims

1. A method for anticorrosion of a flue for discharging wet desulfurization flue gas, characterized in that: The following steps are involved: Step 1, prefabricate a glass fiber reinforced plastic lining (2); Step 2, prefabricate components for connecting the glass fiber reinforced plastic lining (2) and the flue (1), and simultaneously prefabricate supporting components for the glass fiber reinforced plastic lining (2); Step 3, install the glass fiber reinforced plastic lining (2) in sections in the flue (1); Step 4, use the connecting components prefabricated in Step 2 to connect the glass fiber reinforced plastic lining (2) and the flue (1) so that the two are fixed; simultaneously, install the supporting components prefabricated in Step 2 inside the glass fiber reinforced plastic lining (2) so that the supporting components are closely attached to the inner wall of the glass fiber reinforced plastic lining (2); Step 5, open a clean flue inlet (4) for receiving flue gas and set an acid discharge system; Step 6, perform anti-corrosion treatment on the glass fiber reinforced plastic lining (2), the connecting components, the supporting components, the clean flue inlet (4) and the acid discharge system.

2. The anticorrosion method for a flue for discharging wet desulfurization flue gas according to claim 1, characterized in that: The process of prefabricating the FRP lining (2) in step 1 is as follows: firstly, a layer of 300g / ㎡ glass fiber chopped mat is laid, then a layer of resin glue is brushed thereon and the glass fiber chopped mat is soaked with the resin glue, then a layer of 600g / ㎡ glass fiber cloth is laid on the glass fiber chopped mat, and four layers of glass fiber chopped mat and three layers of glass fiber cloth are laid alternately in succession.

3. The anticorrosion method for a flue for discharging wet desulfurization flue gas according to claim 2, characterized in that: The overall thickness of the four layers of glass fiber chopped strand mat and the three layers of glass fiber cloth is not less than 6.5 mm, and they need to be naturally solidified for more than 12 hours after being laid; the weight of the resin glue accounts for no less than 60% of the total weight of the glass fiber reinforced plastic lining (2); the connecting components in step 2 include stainless steel expansion bolts, and the glass fiber reinforced plastic lining (2) is fixed to the flue (1) through the connecting components in step 4; the supporting components include a door frame (7) and an angle steel (8), the door frame (7) is arranged close to the side wall and the top wall of the glass fiber reinforced plastic lining (2), and the angle steel (8) is installed between adjacent door frames (7); a cross-shaped supporting tube is arranged in the door frame (7).

4. The anticorrosion method for a flue for discharging wet desulfurization flue gas according to claim 1, characterized in that: Before installing the glass fiber reinforced plastic lining (2) in step 3, a filling layer (9) is first arranged on the inner wall of the flue (1) to deal with the gaps at the corners. The specific method is: fill the gaps on the inner wall of the flue (1) with putty formed by mixing resin and talcum powder to ensure that the inner wall of the flue (1) is flat, and the thickness of the filling layer (9) is not less than 13 mm.

5. The anticorrosion method for a flue for discharging wet desulfurization flue gas according to claim 1, characterized in that: After the installation of the glass fiber reinforced plastic lining (2) is completed, a bottom plate reinforcement layer (3) is arranged on the bottom plate surface of the glass fiber reinforced plastic lining (2); the construction process of the bottom plate reinforcement layer (3) is as follows: firstly, a layer of resin glue is brushed on the upper surface of the bottom plate of the glass fiber reinforced plastic lining (2), and then a layer of glass fiber cloth with a thickness of 600g / ㎡ and a thickness of 0.7mm is laid, and pressed tightly, and then a layer of resin glue is brushed on it, and then a layer of glass fiber chopped felt with a thickness of 300g / ㎡ and a thickness of 0.75mm is laid, and then a layer of resin glue is brushed on it to ensure that the glass fiber chopped felt is soaked with the resin glue, and then a layer of glass fiber cloth with a thickness of 600g / ㎡ and a thickness of 0.7mm is laid, and the overall thickness is not less than 3mm. After the bottom plate reinforcement layer (3) is laid, it needs to be naturally solidified for more than 12 hours, and the weight of the resin glue accounts for not less than 60% of the total weight of the bottom plate reinforcement layer (3).

6. The anticorrosion method for a flue for discharging wet desulfurization flue gas according to claim 1, characterized in that: The acid discharge system comprises an acid discharge port (5) and an acid discharge main pipeline (6) connected to each of the acid discharge ports (5) and used to receive the acid liquid from each of the acid discharge ports (5); the acid discharge port (5) is arranged at the lowest point of each section of the flue (1), and the diameter of the acid discharge port (5) is 200 mm.

7. The anticorrosion method for a flue for discharging wet desulfurization flue gas according to claim 1, characterized in that: The anti-corrosion treatment method in step 6 is: hand-laying FRP on the surfaces of the FRP lining (2), connecting parts, supporting parts, clean flue inlet (4) and various parts of the acid discharge system.

8. The anticorrosion method for a flue for discharging wet desulfurization flue gas according to claim 1, characterized in that: The connecting components in step 2 include a fixing box (14) pre-buried in the flue (1), a positioning rod (12) inserted into the fixing box (14) from the inside of the glass fiber reinforced plastic lining (2) and fixed thereto, and a sealing portion connected to the end of the positioning rod (12) for corrosion prevention; a first sinking groove (10) is provided on the inner wall of the flue (1) toward the fixing box (14); a second sinking groove (11) connected to the fixing box (14) is provided inside the flue (1) from the bottom of the first sinking groove (10) toward the fixing box (14); the positioning rod (12) is inserted into the second sinking groove (11), A limiting ring (15) capable of being sleeved with the positioning rod (12) is arranged on the side of the fixing box (14) close to the positioning rod (12); a swing rod (20) rotatably connected to the limiting ring (15) is arranged on the side of the limiting ring (15) away from the positioning rod (12); a positioning portion (21) is arranged at the end of the swing rod (20); and a groove (18) capable of accommodating the positioning portion (21) is correspondingly arranged on the positioning rod (12); when the positioning rod (12) is inserted into the fixing box (14), the straight line connecting the groove (18) and the positioning portion (21) is parallel to the axis of the positioning rod (12).

9. The anticorrosion method for a flue for discharging wet desulfurization flue gas according to claim 8, characterized in that: The swing rod (20) is located at the bottom of the limiting ring (15); the limiting ring (15) corresponds to the positioning portion (21) and is provided with a support sheet (22) below the positioning portion (21); a side of the support sheet (22) close to the positioning portion (21) is connected to an elastic rubber block (23) capable of abutting against the positioning portion (21); an end of the positioning rod (12) close to the fixing box (14) is provided with a spring for facilitating the pushing of the positioning rod (21) toward the edge of the limiting ring (15); The positioning portion (21) is chamfered (25), and a side thereof close to the positioning rod (12) is provided with an inclined surface (24) for being pushed toward the edge of the limiting ring (15) by the positioning rod (12); the sealing portion comprises an anti-corrosion disk (13) connected to one end of the positioning rod (12) and disposed inside the first trough (10); a connection reinforcement portion (17) is provided on the outside of the anti-corrosion disk (13); and a sealing layer (16) is filled between the outside of the anti-corrosion disk (13) and the side wall of the first trough (10).

10. The anticorrosion method for a flue for discharging wet desulfurization flue gas according to claim 9, characterized in that: The connection reinforcement part (17) is a convex particle and / or a concave depression; the anti-corrosion disk (13) is formed by curing unsaturated polyester resin; the sealing layer (16) is an intumescent anti-corrosion paint with a curing agent added or an epoxy resin paint with an intumescent agent and a curing agent added.

Images