External magnetic pressure fitting type under-pressure plugging method for gas pipeline

Abstract

The invention relates to the technical field of emergency maintenance of gas pipelines, in particular to an external magnetic pressure fitting type under-pressure plugging method for a gas pipeline, which adopts a complete external operation and zero-fire risk magnetic pressure fitting type plugging method, dynamically adapts to the external contour curvature of the pipeline through an arc-shaped electromagnet, and is combined with an anti-corrosion sealing material. The gas pipeline leakage point online plugging method has the beneficial effects that the gas pipeline leakage point online plugging is realized, the plugging time is saved, the plugging efficiency is improved, the sealing effect is good, and the sealing safety is high.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of gas pipeline emergency repair, and particularly relates to a coal gas pipeline external magnetic pressure fitting type pressurized plugging method. BACKGROUND

[0002] Gas pipelines play an important role in metallurgical industrial enterprises, but due to multiple factors such as medium corrosion and welding quality, coal gas pipeline leakage often occurs in the production and operation of enterprises. Coal gas pipeline leakage will cause the interruption of enterprise production, affect product delivery, cause economic losses, and may also cause fire, explosion and other safety accidents, making the enterprise face the risk of equipment damage, personnel casualties and other risks, and seriously damaging the reputation and image of the enterprise. In addition to the above problems, industrial production often relies on continuous and stable energy supply, and coal gas leakage may cause the entire production line to be paralyzed, leading to the obstruction of the supply of upstream and downstream industrial chains and affecting the overall production order of the industry. Especially in the metallurgical production process, the use of coal gas is large, and once leakage occurs, not only will high-temperature furnaces and other equipment be unable to operate normally due to abnormal coal gas supply, but also explosive mixed gas may be formed in the relatively closed space of the workshop, and slight fire or static electricity may cause violent explosion, causing serious personnel casualties and property losses. At the same time, the leaked coal gas will also pollute the environment and harm the surrounding ecology.

[0003] The traditional coal gas pipeline plugging technology has many problems: Internal plugging (folding plugging head): requires hole opening and device implantation, is hindered by sediments, and the sealing failure rate is >40%.

[0004] External welding (sealing box method): high risk of fire, and the pipe wall thickness needs to be >4mm (corrosion area is often not up to standard).

[0005] High polymer ceramic sealing: combined with a strong magnet, the magnet force is not easy to adjust, and the magnet contact surface is a plane, the fitting degree is poor, and the high polymer ceramic sealing effect cannot be effectively played under abnormal conditions.

[0006] The patent with the authorization publication number CN209084280U "gas pipeline online leak stop structure" discloses a leak stop structure which can carry out leak stop and repair on the gas pipeline online, the gas pipeline online leak stop structure comprises a vent pipe, one end of the vent pipe is a sleeve joint end, the other end of the vent pipe is a discharge end; the sleeve joint end is sleeved at the leakage point of the gas pipeline and surrounds the leakage point, and the sleeve joint end is connected with the gas pipeline by welding; a valve is arranged between the sleeve joint end and the discharge end. The patent can carry out online leak stop and repair on the leakage point after the gas pipeline leaks, can not need to close the pipeline, can make the pipeline in the working state of pressure conveying, can hardly affect the normal production activities, can effectively avoid the influence of pipeline repair on production activities, and can ensure production efficiency. However, the pure mechanical sleeve joint sealing of the patent has poor sealing performance and poor sealing effect, and secondary leakage is easy to occur. SUMMARY

[0007] In order to overcome the defects of the prior art, the present application provides a coal gas pipeline external magnetic pressure fitting type pressure sealing method. The magnetic pressure fitting type sealing method is completely externally operated and has zero fire risk. The arc-shaped electromagnet dynamically adapts to the curvature of the outer contour of the pipeline, and in combination with the corrosion-resistant sealing material, the arc-shaped electromagnet realizes rapid sealing with a leakage rate of ≤0.1%. The coal gas pipeline leak point is sealed online, the sealing time is saved, the sealing efficiency is improved, the sealing effect is good, and the sealing safety is high.

[0008] In order to achieve the above-mentioned purpose, the present application adopts the following technical scheme: A coal gas pipeline external magnetic pressure fitting type pressure sealing method, the sealing method realizes the pressing of the flexible iron sheet coated with the sealing material and the pipe wall by the electromagnetic force of the arc-shaped electromagnet. The specific sealing method is as follows: S1, leakage point positioning and parameter measurement: The actual curvature of the outer diameter of the pipeline and the corrosion pit depth are obtained by using a laser scanner, and the arc parameter of the arc-shaped electromagnet is obtained. According to the coal gas pressure and the size of the leakage port, the minimum magnetic attraction force is calculated, and the minimum magnetic attraction force reaches 500-800 N. S2, external auxiliary material and magnetic pressure curing: The sealing material is sprayed to the outer surface of the flexible iron sheet, and the flexible iron sheet coated with the sealing material is manually pressed and attached to the outer wall of the pipeline leakage point, and the coverage range exceeds the edge of the leakage point by ≥100 mm. The arc-shaped electromagnet is adsorbed to the outer side of the flexible iron sheet, the magnetic force is activated by power-on, and the pressing time is 15-25 min to the initial setting of the sealing material. S3, removal and sealing verification: The electromagnet is powered off and removed, and the CO concentration around is detected, and the leakage rate is ≤24 ppm.

[0009] Further, the energizing voltage in step S2 is 24V, and the current is 1.5-10A.

[0010] Further, the initial compression strength of the sealing material in step S2 reaches 2-5MPa.

[0011] Further, the electromagnet adopts an explosion-proof shell, and the power supply system is integrated with short-circuit protection.

[0012] Further, the sealing material is formed by mixing a base material and a reinforcing agent, the base material adopts polyether polyol + isocyanate as a matrix, 30wt% nano silicon carbide and 15vol% polytetrafluoroethylene fiber are added to form a ternary composite sealing material, and the reinforcing agent is polytetrafluoroethylene fiber.

[0013] Further, the sealing material has a temperature resistance of 280℃ or below, a compression strength of ≥20MPa, and a moisture curing time of ≤15min.

[0014] Further, the flexible iron sheet has a thickness of 0.3-0.5mm and is made of stainless steel.

[0015] Further, the edge of the flexible iron sheet has a sawtooth structure.

[0016] Compared with the prior art, the present application has the following advantages: 1) Online repair: The present application realizes online repair of the pipeline under the condition of non-stop and pressure operation, without the need for complex shutdown preparation work, effectively avoiding production interruption and economic loss caused by pipeline shutdown, and ensuring continuous production requirements.

[0017] 2) High-strength sealing: The high-molecular ceramic composite sealing layer formed by the electromagnetic-material collaborative sealing mechanism has excellent physical properties, good sealing performance, and good sealing effect.

[0018] 3) Plugging efficiency: The electromagnetic iron adsorption compression sealing operation time is ≤45min, which saves the plugging time of the gas pipeline, improves the plugging efficiency, and reduces the labor workload.

[0019] 4) Safety benefits: The electromagnetic iron is used to adsorb and compress the sealing material, and the flexible iron sheet is used to plug the gas pipeline, which can completely avoid the risk of fire / explosion, has high safety level, and is suitable for Class I explosion-proof area of metallurgical enterprises.

[0020] 5) Economic Efficiency: From a material cost perspective, the arc-shaped electromagnet and polymer ceramic composite material used in this invention reduce costs by approximately 80% compared to the special welding materials and equipment used in traditional welding repair. Furthermore, the device is rationally designed; since the electromagnet generates magnetic force when energized and the force disappears when the electromagnet is de-energized, after sealing with the polymer ceramic sealing material, it can be removed and reused after the polymer ceramic sealing material solidifies, further reducing long-term operating costs. This demonstrates significant economic advantages and facilitates its widespread application in the industrial sector. Attached Figure Description

[0021] Fig. 1 This is a schematic diagram of an external magnetic pressure bonding pressurized sealing method for gas pipelines provided by the present invention.

[0022] Fig. 2 This is a schematic diagram of the sealing process provided by the present invention.

[0023] In the diagram: 1. Curved electromagnet; 2. Flexible sheet metal; 3. Sealing material; 4. Leak point; 5. Pipeline. Detailed Implementation

[0024] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings: like Figs. 1-2 As shown, a method for external magnetic pressure bonding and pressurized sealing of gas pipelines is described. This sealing method is entirely external: the arc-shaped electromagnet 1, the flexible iron sheet 2, and the sealing material 3 all act on the outer wall of the pipeline 5, preventing intrusion into the pipeline 5 and solving the problem of deposit interference; non-welding physical bonding: the arc-shaped electromagnet 1 applies electromagnetic force to achieve the pressing of the flexible iron sheet 2 coated with the sealing material 3 against the pipe wall, eliminating the generation of sparks. The specific sealing method is as follows: S1. Leak location and parameter measurement: A laser scanner is used to obtain the actual curvature of the outer diameter of pipe 5 and the depth of corrosion pits, and to obtain the curvature parameters of arc electromagnet 1. The curvature of arc electromagnet 1 is customized according to the actual measured outer contour of pipe 5. Standard pipes are pre-processed and can be replaced according to different sizes to ensure the fit between the outer wall of pipe 5 and the sealing device. Based on the gas pressure and leak size, calculate the minimum magnetic attraction force. The minimum magnetic attraction force needs to be dynamically calculated according to the actual working conditions of the gas pipeline. Under normal conditions, the minimum magnetic attraction force generally needs to reach 500-800N to ensure that the compression strength is sufficient to resist gas pressure fluctuations. S2, External Auxiliary Materials and Magnetically Pressed Curing: Spray the sealing material 3 onto the outer surface of the flexible iron sheet 2, and manually press the side of the flexible iron sheet coated with the sealing material 3 onto the outer wall of the leak point 4 of the pipe 5, with the coverage area extending ≥100mm beyond the edge of the leak point 4. Arc-shaped electromagnet 1 is adsorbed on the outer side of flexible iron sheet 2, and the magnetic force is activated by power supply. The current needs to be dynamically adjusted according to the pipeline pressure and the size of the leakage point: usually fixed at 24V DC according to the requirements of explosion-proof safety; the current can be adjusted in the range of 1.5-10A, corresponding to the magnetic attraction force of 500-1500N.

[0025] Compression for 15-25min to initial setting of sealing material 3, and the initial setting of sealing material 3 is that the compressive strength reaches 2-5MPa; S3, remove and seal verification: Disconnect the electromagnet and remove it, and detect the CO concentration around it. The leakage rate is ≤24ppm.

[0026] Arc-shaped electromagnet 1 adopts an explosion-proof shell, and the power supply system integrates short-circuit protection.

[0027] Sealing material 3 is mixed by a base material and a reinforcing agent. The base material has the following chemical composition by weight percentage: polyether polyol + isocyanate is used as the matrix, 30wt% nanometer silicon carbide and 15vol% polytetrafluoroethylene fiber are added to form a ternary composite sealing material; the reinforcing agent is polytetrafluoroethylene fiber. The sealing material 3 can withstand a temperature of 280℃ or below, and has a compressive strength of ≥20MPa; the moisture curing time is ≤15min.

[0028] Flexible iron sheet 2 is a 0.3-0.5mm thick stainless steel sheet with a sawtooth structure on the edge to enhance the anchoring force of the sealing material.

[0029] As shown in Figs. 1-2 The plugging principle of the external magnetic pressure fitting type plugging method for the gas pipeline is as follows: (1) External dynamic compression mechanism: the electromagnetic force can adapt to the fluctuation of the gas pressure in real time, avoiding the debonding caused by pressure pulsation in traditional static sealing; the flexible iron sheet compensates for the corrosion and indentation of the pipe wall, and can completely fit when the indentation depth is ≤3mm.

[0030] (2) Anti-explosion sealing material: nanometer silicon carbide powder forms SiC-SiC grain boundary in the gas environment, blocking the H2S penetration path; the polytetrafluoroethylene fiber network inhibits brittle fracture of the material, and the impact resistance is improved by 300%.

[0031] (3) Safety anti-explosion design: arc-shaped electromagnet 1 adopts an explosion-proof shell with an explosion-proof grade of Ex-d-IIC-T4, and the power supply system integrates short-circuit protection.

[0032] Embodiment: According to the corrosion and leakage plugging of DN800 coke oven gas main 1. Working condition parameters: The outer diameter of the pipeline 5 is 1200mm; the leakage point 4 is a crack with a length of 35mm, and the medium pressure is 12KPa; the outer contour scanning of the pipeline 5 shows that the maximum indentation depth is 2.8mm 2. Key component preparation: (1) Arc electromagnet 1: The arc is customized according to DN1200 pipeline data, and a 500N grade Ex-d-IIC-T4 explosion-proof electromagnet is selected (2) Flexible iron sheet 2: Material: 316L stainless steel, thickness 0.5mm; size: 500mm x 400mm, covering the edge of the leakage point 4 extension ≥ 150mm; edge treatment: sawtooth structure, depth 0.5mm, spacing 3mm.

[0033] (3) Sealing material 3: High polymer ceramic sealing material 1, using polyether polyol + isocyanate as the matrix, adding 30wt% nano silicon carbide and 15vol% polytetrafluoroethylene fiber, forming a ternary composite sealing material.

[0034] 3. Plugging operation process: Step 1: Use a two-component glue gun to spray the mixed sealing material 3 to the inner surface of the flexible iron sheet 2, with a coating thickness of 4mm, and manually press and paste it to the leakage point 4 to exclude air bubbles.

[0035] Step 2: The arc electromagnet 1 is adsorbed on the outer side of the flexible iron sheet 2, and 24V direct current is passed through with a current of 1.5A, maintaining pressure for 20min, and the initial setting pressure strength of the sealing material 3 reaches 2MPa.

[0036] Step 3: After removing the arc electromagnet 1: leakage rate detection: CO concentration detector shows ≤24ppm 4. Technical effects: Efficiency: total operation time 36 minutes, operation time reduced; service life: after 10 years of simulated working conditions, the leakage rate is still <0.05%; economy: single cost 210 yuan, compared with traditional welding 3000 yuan, the cost is significantly reduced.

[0037] The above describes only the preferred specific embodiments of the present application, but the protection scope of the present application is not limited thereto, and any skilled person in the art can make equivalent replacements or changes within the technical scope disclosed by the present application according to the technical solutions and concepts of the present application, which should be covered within the protection scope of the present application.

Claims

1. A coal gas pipeline external magnetic pressure fitting type pressure sealing method, which realizes the pressure bonding of a flexible iron sheet coated with a sealing material and a pipe wall by applying an electromagnetic force by an arc-shaped electromagnet, characterized in that, The specific plugging method is as follows: S1, leak positioning and parameter measurement: The actual curvature of the outer diameter of the pipeline and the corrosion pit depth are obtained by using a laser scanner, and the arc parameter of the arc electromagnet is obtained; According to the gas pressure and the size of the leakage port, the minimum magnetic attraction force is calculated, and the minimum magnetic attraction force reaches 500-800N; S2, external auxiliary material and magnetic pressure curing: The sealing material is sprayed to the outer surface of the flexible iron sheet, and the flexible iron sheet coated with the sealing material is manually pressed and pasted to the outer wall of the pipeline leak outside, and the coverage range exceeds the edge of the leak by ≥100mm; The arc electromagnet is adsorbed to the outside of the flexible iron sheet, and the magnetic force is activated by power-on to press for 15-25min until the sealing material is initially cured; S3, removal and sealing verification: The electromagnet is removed after power-off, and the CO concentration around is detected, and the leakage rate is ≤24ppm.

2. The method for sealing the outside of a coal gas pipeline under pressure by magnetic pressing and adhering according to claim 1, characterized in that, The power-on voltage in step S2 is 24V, and the current is 1.5-10A.

3. The method for sealing the outside of a coal gas pipeline according to claim 1, characterized in that, The initial curing of the sealing material in step S2 is that the compressive strength reaches 2-5MPa.

4. The method for sealing the outside of a coal gas pipeline according to claim 1, characterized in that, The electromagnet adopts an explosion-proof shell, and the power supply system is integrated with short circuit protection.

5. The method of claim 1, wherein the method further comprises: The sealing material is mixed by a base material and a reinforcing agent, the base material uses polyether polyol+isocyanate as a matrix, adds 30wt% nanometer silicon carbide and 15vol% polytetrafluoroethylene fiber to form a ternary composite sealing material; the reinforcing agent is polytetrafluoroethylene fiber.

6. The method for sealing the outside of a coal gas pipeline according to claim 1 or 5, characterized in that, The sealing material can resist temperature below 280℃; the compressive strength is ≥20MPa; and the moisture curing time is ≤15min.

7. The method of claim 1, wherein the method further comprises: The flexible iron sheet has a thickness of 0.3-0.5mm of stainless steel sheet.

8. The method according to claim 1 or 7, characterized in that, The edge of the flexible iron sheet is in a sawtooth structure.

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