Corrosion-proof construction process for gasifier gold weld

Abstract

The application discloses a kind of gasification furnace gold weld joint anticorrosion construction process, comprising the following steps: surface treatment, using polishing device along gasification furnace movement, and respectively to the original paint layer inside and outside weld joint polishing, rust, grinding, decontamination, dust removal;Paint preparation, primer and topcoat are mixed, diluent, curing agent is added, and is stirred uniformly;Primer is applied, after surface pretreatment acceptance, interval time is not more than 4 hours, and the surface after processing is not allowed to expose in air for a long time;Coat, primer is dry, then brush middle, topcoat, and the last paint can be brushed only after the surface of the previous paint is dry, to ensure excellent interlayer adhesion, interval time is not more than 48 hours;Hand over acceptance of work. By surface treatment, paint preparation, primer coating, coating, hand over acceptance of work of weld joint of gasification furnace, a complete set of construction process, weld joint can be carried out anticorrosion treatment, so that weld joint reaches anticorrosion requirement.

Description

Technical Field

[0001] This invention relates to the field of corrosion protection technology, specifically to a corrosion protection construction process for gold weld seams in gasifiers. Background Technology

[0002] A gasifier is a device that converts carbonaceous materials (such as coal, biomass, and waste) into combustible gases (syngas, mainly composed of CO and H2). The welds of a gasifier are a critical element in its structural safety and operational reliability, especially in high-temperature, high-pressure, or corrosive environments, where weld quality directly impacts the equipment's lifespan and safety.

[0003] Argon arc welding (TIG), submerged arc welding (SAW), or laser welding are mostly used to ensure the tightness of the weld. After welding, the weld needs to be treated with anti-corrosion. However, the current anti-corrosion treatment of gasifier welds has the following problems: (1) There is a lack of a complete set of processes for anti-corrosion treatment of gasifier welds; (2) When treating the surface of the weld, the inside and outside of the weld need to be ground. Before grinding, the debris is cleaned from the weld by hand with a hand-held cleaning brush for pre-cleaning. Then, the angle grinder is used for grinding. After grinding, the debris generated after grinding is cleaned by hand, resulting in low efficiency of surface treatment of the weld. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a corrosion protection construction process for the gold weld seam of a gasifier, thereby solving the problem of low efficiency in surface treatment of gasifier weld seams mentioned in the background section.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0006] A corrosion protection construction process for the gold weld seam of a gasifier includes the following steps:

[0007] Step 1: Surface Treatment

[0008] The grinding device moves along the gasifier and grinds the original paint layer inside and outside the weld, removing rust, smoothing, dirt, and dust to facilitate the inspection of the weld by the inspection unit.

[0009] Step Two: Paint Preparation

[0010] Mix the primer and topcoat, add thinner and hardener, and stir well. Before use, let it stand for 15-30 minutes to mature. The maturation time may be shortened or extended depending on the temperature.

[0011] Step 3: Apply primer

[0012] After the surface pretreatment has passed the acceptance test, the primer should be applied, with an interval of no more than 4 hours. The treated surface is not allowed to be exposed to the air for a long time.

[0013] Step 4: Apply intermediate and top coats

[0014] After the primer is fully dry, apply the intermediate and top coats. Each coat must be applied only after the previous coat has dried to ensure excellent interlayer adhesion. The interval between coats should not exceed 48 hours.

[0015] Step 5: Handover and acceptance.

[0016] Preferably, in step one, the gasifier weld seam is ground inside and out, and the entire area within 250mm above and below the weld seam is ground smooth, exposing the metal luster of the weld seam, and the weld seam is ground smooth.

[0017] Preferably, during grinding, the welding slag, burrs, and sharp corners on the surface of the component are treated using a grinding device to ensure the aesthetics of the surface coating; during dust removal, after the surface treatment is completed, the surface dust is thoroughly removed by blowing with a dry and clean air compressor, and the cleaned surface should not be touched by hand to ensure that the substrate surface is clean and dry.

[0018] Preferably, in step two, when preparing the paint, the entire bucket of paint should be uniform without sediment or color difference, and it should not be mixed with regular paint. For two-component coatings, the material mixing ratio should be strictly followed, and the paint should be allowed to mature for the required time before use. The addition of thinner should be strictly in accordance with the specifications, generally not exceeding 5%, and paint that has exceeded its shelf life is strictly prohibited from use.

[0019] Preferably, in step three, if the atmospheric environment is harsh, such as high humidity or salt spray in the air, the interval time should be further shortened to ensure that no yellow rust is generated on the metal surface, and the coating should be applied evenly without any omissions.

[0020] Preferably, in step four, it is also necessary to promptly remove any newly adhering dust and debris from the primer surface during the coating interval; if high humidity occurs before it is completely dry, the paint film will turn white. In this case, when recoating, the whitened film should be wiped clean with solvent or sandpaper to ensure good interlayer adhesion; the final topcoat should be applied to ensure a uniform color without color difference.

[0021] The system includes an AGV (Automated Guided Vehicle) trolley. A first hydraulic cylinder is mounted on the AGV trolley. A side plate is connected to the telescopic end of the first hydraulic cylinder. A housing is mounted on one side of the side plate. Second hydraulic cylinders are hinged to both ends of the housing on the side plate. Deflection plates are hinged to both ends of the housing. The telescopic ends of the second hydraulic cylinders are movably connected to the deflection plates. Two first connecting plates are connected to the side of the housing away from the side plate. A first rotating shaft is rotatably connected to the two first connecting plates. A grinding cylinder is splined onto the first rotating shaft. Two second connecting plates are connected to the side of the deflection plates away from the side plate. Second rotating shafts are rotatably connected to the two second rotating shafts. A cleaning cylinder is splined onto the second rotating shaft. Several cleaning brushes are fixed to the outer wall of the cleaning cylinder. The housing is equipped with a drive mechanism that drives the first rotating shaft and the two second rotating shafts to rotate simultaneously.

[0022] Preferably, the drive mechanism includes a motor installed inside the housing, a drive shaft connected to the motor via a coupling, a drive wheel fixedly connected to the drive shaft, driven wheels fixedly connected to the first rotating shaft and the second rotating shaft respectively, and a guide wheel rotatably connected to the housing and close to the grinding cylinder. The drive wheel, the guide wheel, and the three driven wheels are connected by a transmission belt.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] (1) By performing a complete set of construction processes, including surface treatment, paint preparation, primer application, intermediate and topcoat application, and handover and acceptance of the gasifier weld, the weld can be protected against corrosion, thus meeting the corrosion protection requirements.

[0025] (2) A working platform is built on the gasifier and a guide rail is installed on the working platform to guide the AGV trolley. When the weld surface is treated, the first hydraulic cylinder is extended to push the side plate so that the grinding cylinder contacts the weld. The second hydraulic cylinder is extended to drive the deflection plate to deflect towards the weld so that the cleaning brush contacts the weld. The weld is pre-cleaned by the cleaning brush at one end, and the pre-cleaned weld is ground by the grinding cylinder in the middle. The ground weld is cleaned by the cleaning brush at the other end. Combined with the work of the AGV trolley, the automatic pre-cleaning, grinding and dust removal of the weld is realized, which greatly improves the efficiency of surface treatment. Attached Figure Description

[0026] Figure 1 This is a process flow diagram of the present invention;

[0027] Figure 2 This is a schematic diagram of the grinding device;

[0028] Figure 3 This is a top view of the grinding device;

[0029] Figure 4 This is a top view of the weld seam during grinding.

[0030] In the diagram: 1-AGV trolley, 2-first hydraulic cylinder, 3-side plate, 4-box body, 5-second hydraulic cylinder, 6-deflection plate, 7-first connecting plate, 8-first rotating shaft, 9-grinding cylinder, 10-second connecting plate, 11-second rotating shaft, 12-cleaning cylinder, 13-drive wheel, 14-driven wheel, 15-guide wheel, 16-transmission belt, 17-gasifier, 18-track, 19-working platform. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] Example 1

[0033] Please see Figure 1 A corrosion protection construction process for the gold weld seam of a gasifier includes the following steps:

[0034] Step 1: Surface Treatment

[0035] The grinding device moves along the gasifier and grinds the original paint layer inside and outside the weld, removing weld slag, burrs, and sharp edges from the component surface to remove rust and smooth the surface. During grinding, the entire area within 250mm above and below the weld is ground smooth, exposing the metal luster of the weld. The weld is also ground smooth to ensure the aesthetics of the surface coating. After the surface treatment is completed, the surface dust is thoroughly removed by blowing with a dry and clean air compressor. The cleaned surface must not be touched by hand to ensure that the substrate surface is clean and dry, so as to facilitate the inspection of the weld by the inspection unit.

[0036] Step Two: Paint Preparation

[0037] Primer and topcoat must be thoroughly stirred before use to ensure the entire container of paint is uniform, free of sediment and color variation. Do not mix with regular paint. For two-component coatings, strictly adhere to the material mixing ratio and allow for the required curing time before use. Do not reseal the paint after mixing; prepare only the amount needed. Thinner addition must strictly follow the specifications, generally not exceeding 5%. Expired paint is strictly prohibited from use. A designated person should add the hardener to the paint according to the proportions specified in the product instructions and stir thoroughly. Before use, allow it to stand for 15-30 minutes to cure; the curing time may be shortened or extended depending on the temperature.

[0038] Step 3: Apply primer

[0039] Primer application: After the surface pretreatment is completed and the metal surface passes inspection, the primer should be applied as soon as possible after the inspection is passed. The interval between applications should not exceed 4 hours, and prolonged exposure to air is not allowed. In harsh atmospheric conditions (such as high humidity or salt spray in the air), the interval should be further shortened to ensure that no yellow rust forms on the metal surface. The primer should be applied evenly and without any omissions.

[0040] Step 4: Apply intermediate and top coats

[0041] After the primer has fully dried (usually within 24 hours), apply the (intermediate) topcoat. Each subsequent coat must be applied only after the previous coat has completely dried to ensure excellent interlayer adhesion. The interval between coats should generally not exceed 48 hours. Furthermore, promptly remove any fresh dust or debris that may have adhered to the primer surface during the paint application interval. If the primer is exposed to high humidity conditions such as wind, snow, rain, or condensation before it is fully dry, the paint film may whiten. In such cases, before recoating, first clean the whitened film with solvent or sandpaper to ensure good interlayer adhesion. Apply the final topcoat evenly, ensuring a uniform color without any color difference.

[0042] Before painting, the surface of the steel structure should be visually inspected to ensure that its surface cleanliness and surface roughness meet the specifications.

[0043] If the paint surface is skinned or contains other impurities, it should be filtered and removed before use. If the paint contains fillers that are prone to settling, it should be stirred well before use.

[0044] Weather requirements for painting should follow the paint product instructions. The ideal temperature for paint application is between 4-30℃ (≥10℃ according to the client's requirements), and the relative humidity should be below 85%. The painted surface must be free of defects such as runs and air bubbles.

[0045] The surface of the object to be coated is dry and free of moisture.

[0046] Sufficient drying time should be allowed between each coat of paint; the specific interval depends on the material properties.

[0047] The coating should not be cloudy, thickened, sedimented, or have a skin.

[0048] During the application process, the surface of the object to be coated should not exhibit any defects such as sagging, bleeding, color seepage, slow drying, stickiness, roughness, discoloration, whitening, shrinkage, orange peel, or pinholes.

[0049] After construction, issues such as peeling, powdering, bubbling, cracking, and glare will not occur.

[0050] After the coating is applied, the surface of the object has a uniform and consistent color, good film-forming properties, sufficient mechanical strength, and a beautiful appearance.

[0051] During the coating application process, the coating should be applied sequentially from top to bottom and from left to right, according to the site conditions and the location of different objects. The coating should be applied evenly and consistently, without any peeling, wrinkling, missed areas, or incorrect coating. To ensure good adhesion between coating layers, sufficient drying time should generally be allowed after the first coat before proceeding with the next step, ensuring a good paint film, consistent color, and coating thickness that meets design requirements.

[0052] The construction environment and temperature are generally suitable between 4 and 30℃ (the temperature for this construction is controlled at ≥10℃), and the relative humidity is not greater than 80%.

[0053] Each coating layer must be carefully inspected after application. Any quality issues must be addressed immediately. If any scratches or damage occur, the coating should be repaired according to the established procedure to achieve the best anti-corrosion effect.

[0054] The painting process should proceed from top to bottom, from left to right, from inside to outside, and from difficult areas to easy areas, ensuring even application. When painting, you can use horizontal or vertical brushes, overlapping each coat by half, paying attention to maintaining evenness, and touching up any hard-to-reach areas. Each coat should be even, without any gaps, wrinkles, or runs.

[0055] To ensure good paint quality, ten things should be avoided during application:

[0056] a. Do not paint over areas with rust.

[0057] b. Do not brush on surfaces with dust or oil stains.

[0058] c. Do not apply when the surface is wet due to rain or snow.

[0059] d. Do not paint in strong winds.

[0060] e. Do not apply topcoat without primer.

[0061] f. Do not apply the next coat of paint before the base coat is dry.

[0062] g. Do not apply paint if the temperature does not meet the requirements.

[0063] h. Do not repaint if the paint film is damaged.

[0064] i. Do not brush when the temperature exceeds 80%.

[0065] j. Do not paint without inspection.

[0066] Step 5: Handover and acceptance.

[0067] During construction, it is important to note that painting can easily cause secondary pollution, contaminating equipment, pipes, and exterior surfaces. Therefore, painting should avoid these areas as much as possible. If unavoidable (valve nameplates, valve stems, etc., especially the valve stem area, to prevent splashes, and protection of instruments / valves near cold boxes, etc.), use tarpaulins or advertising boards to cover equipment, pipes, and exterior surfaces. Paint buckets must be placed securely and stably to prevent them from falling and causing secondary pollution. Dust pollution also occurs during manual and mechanical rust removal; therefore, the area of ​​dust pollution should be kept as small as possible during painting. Construction workers should wear masks and protective gear to prevent dust from entering their mouths and causing personal injury.

[0068] Waste paintbrushes, waste cotton yarn, and waste paint buckets after construction can pollute the soil. These old tools, materials, and packaging items should be cleaned up and recycled before the end of each workday. They should not be discarded at will, and a waste storage area should be set up for centralized treatment.

[0069] After steel components are painted, they should be temporarily enclosed and isolated to prevent them from being stepped on and damaged.

[0070] Do not allow painted steel components to come into contact with acidic liquids to prevent damage to the coating.

[0071] Example 2

[0072] Based on Example 1, please refer to Figure 2 , Figure 3 , Figure 4A grinding device for grinding the gold weld seam of the gasifier as described in claim 6 includes an AGV trolley 1, a first hydraulic cylinder 2 mounted on the AGV trolley 1, a side plate 3 connected to the telescopic end of the first hydraulic cylinder 2, a housing 4 mounted on one side of the side plate 3, second hydraulic cylinders 5 hinged to both ends of the housing 4 on the side plate 3, deflection plates 6 hinged to both ends of the housing 4, the telescopic end of the second hydraulic cylinder 5 being movably connected to the deflection plate 6, and two first connecting plates 7 connected to the side of the housing 4 away from the side plate. A first rotating shaft 8 is rotatably connected to the housing 7. A grinding cylinder 9 is splinedly connected to the first rotating shaft 8. Two second connecting plates 10 are connected to the side of the deflecting plate 6 away from the side plate. A second rotating shaft 11 is rotatably connected to the two second connecting plates 10. A cleaning cylinder 12 is splinedly connected to the second rotating shaft 11. Several cleaning brushes are fixed on the outer wall of the cleaning cylinder 12. The cleaning brushes at the front end of the grinding are wire brushes, and the cleaning brushes at the rear end of the grinding are bristle brushes. The housing 4 is equipped with a drive mechanism that drives the first rotating shaft 8 and the two second rotating shafts 11 to rotate simultaneously. The drive mechanism includes a motor installed in the housing, a transmission shaft connected to the motor via a coupling, a drive wheel 13 fixedly connected to the transmission shaft, driven wheels 14 fixedly connected to the first rotating shaft 8 and the second rotating shaft 11 respectively, and a guide wheel 15 rotatably connected to the housing and close to the grinding cylinder. The drive wheel 13, the guide wheel 15, and the three driven wheels 14 are connected by a transmission belt 16.

[0073] Circumferential working platforms are constructed on the inner and outer walls of the gasifier. These platforms are raised sequentially from low to high to facilitate surface treatment of each weld layer. Guide rails are installed on the working platforms. When the gasifier is cylindrical, both the working platform and guide rails are annular; when the gasifier is rectangular, the working platform is rectangular, and the guide rails are rounded rectangles. The guide rails guide the movement of the AGV (Automated Guided Vehicle). A hydraulic system and a control system are also installed on the AGV. The hydraulic system provides power to the first and second hydraulic cylinders, while the control system controls the operation of the motor, the first and second hydraulic cylinders, and the AGV.

[0074] The working principle of this embodiment is as follows: After the guide rail and AGV trolley are installed, when the gasifier is cylindrical, the first hydraulic cylinder 2 is extended to push the side plate 3, so that the grinding cylinder 9 contacts the weld. Then, the second hydraulic cylinder 5 is extended to drive the deflection plate 6 to deflect towards the weld, so that the cleaning brush contacts the weld, thus matching gasifiers of different radii. When the gasifier is rectangular, the second hydraulic cylinder 5 does not work, and the two deflection plates 6 are on the same straight line. During operation, the weld is pre-cleaned by the wire brush at the front end, the pre-cleaned weld is ground by the grinding cylinder in the middle, and the ground weld is cleaned by the brush at the rear end to remove dust. Combined with the movement of the AGV trolley along the guide rail, the automatic pre-cleaning, grinding, and dust removal of the weld are achieved, greatly improving the efficiency of surface treatment.

[0075] It should be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0076] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A gasifier gold weld corrosion prevention construction process, characterized in that: It comprises the following steps: Step one: surface treatment Use the polishing device to move along the gasifier, and polish the original paint layer inside and outside the weld respectively, remove rust, smooth, remove dirt, and dust, to facilitate the detection unit to detect the weld; The polishing device comprises an AGV trolley (1), a first hydraulic cylinder (2) is installed on the AGV trolley (1), the extension end of the first hydraulic cylinder (2) is connected with a side plate (3), a box body (4) is installed on one side of the side plate (3), a second hydraulic cylinder (5) is hinged on both ends of the box body (4), a deflection plate (6) is hinged on both ends of the box body (4), the extension end of the second hydraulic cylinder (5) is movably connected with the deflection plate (6), two first connecting plates (7) are connected with one side of the box body (4) away from the side plate, a first rotating shaft (8) is rotatably connected on the two first connecting plates (7), a polishing cylinder (9) is spline-connected on the first rotating shaft (8), two second connecting plates (10) are connected with one side of the deflection plate (6) away from the side plate, a second rotating shaft (11) is rotatably connected on the two second connecting plates (10), a cleaning cylinder (12) is spline-connected on the second rotating shaft (11), a plurality of cleaning brushes are fixed on the outer wall of the cleaning cylinder (12), and a driving mechanism for driving the first rotating shaft (8) and the two second rotating shafts (11) to rotate simultaneously is arranged on the box body (4); Step two: paint preparation Mix the primer and topcoat, add diluent and curing agent, and stir evenly; before use, stand for 15-30 min for curing, and the curing time is shortened or lengthened according to the temperature; Step three: primer coating After the surface pretreatment is qualified, brush the primer, and the interval time should not exceed 4 hours, and the treated surface should not be exposed to the air for a long time; Step four: middle and topcoat coating After the primer is dry, brush the middle and topcoat, and the subsequent paint can be brushed only after the surface of the previous paint is dry, so as to ensure good interlayer adhesion, and the interval time should not exceed 48 hours; the dust and sundries newly adhered to the primer surface during the coating interval should be cleaned in time; if the surface is exposed to high humidity before it is completely dry, the paint film will be whitened, and in this case, the whitened film should be cleaned with solvent or sandpaper, so as to ensure good interlayer adhesion; the last topcoat is brushed as a whole, so as to ensure uniform color without color difference; Step five: acceptance of the project.

2. The gold weld joint anticorrosion construction process of a gasification furnace according to claim 1, characterized in that: In step one, the inside and outside of the gasifier weld are polished, and the weld within a range of 250 mm above and below is polished, the weld is polished flat, and the weld is exposed to metal luster.

3. The gold weld joint anticorrosion construction process of a gasification furnace according to claim 2, characterized in that: During the polishing, the welding slag, burrs and sharp corners on the surface of the component are treated, and the polishing device is used for treatment, so as to ensure the appearance of surface coating; During the dust removal, after the surface treatment is completed, the surface dust is completely removed, a dry and clean air compressor is used for blowing, and the cleaned surface should not be touched by hand, so as to ensure that the surface of the base material is clean and dry.

4. The gold weld joint anticorrosion construction process of a gasification furnace according to claim 3, characterized in that: In step two, when the paint is prepared, the whole barrel of paint should be uniform, without sediment and color difference, and it cannot be mixed with conventional paint, and for two-component paint, it should be prepared according to the material mixing ratio, and used after curing for the required time; the diluent should be strictly prepared according to the specification, and the amount should not exceed 5%, and the paint beyond the use period should not be used.

5. The gold weld joint anticorrosion construction process of a gasification furnace according to claim 4, characterized in that: In step three, the interval time should be further shortened when the atmospheric environment is poor to ensure that no yellow rust appears on the metal surface, and the painting should be uniform without any omission.

6. The gasifier gold weld corrosion prevention construction process of claim 1, wherein: The driving mechanism comprises a motor installed in the box, a transmission shaft connected to the motor through a shaft coupling, a driving wheel (13) fixedly connected to the transmission shaft, driven wheels (14) fixedly connected to the first rotating shaft (8) and the second rotating shaft (11) respectively, a guide wheel (15) rotatably connected to the box and close to the polishing cylinder, and the driving wheel (13), the guide wheel (15) and the three driven wheels (14) are drivingly connected through a transmission belt (16).

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