An effective isolation method for large-diameter coal gas recovery system based on liquid seal balance

Abstract

This invention discloses an effective isolation method for a large-diameter gas recovery system based on liquid seal balance, comprising: installing a U-shaped bend pipe with the same diameter as the main gas pipeline; installing a water replenishment device on the upper part of the riser on one side of the U-shaped bend pipe, installing a liquid level observation component in the middle of the riser on the other side of the U-shaped bend pipe, and installing a drain pipe at the bottom of the U-shaped bend pipe; injecting clean water into the U-shaped bend pipe to an effective height to form a liquid seal barrier; dynamically replenishing water level loss through the water replenishment device during maintenance; closing the valve connecting the U-shaped bend pipe to the main gas pipeline after maintenance, opening the drain pipe at the bottom of the U-shaped bend pipe to drain the accumulated water in the U-shaped bend pipe, and releasing the isolation. By replacing traditional mechanical valves with a liquid seal, zero-leakage isolation of large-diameter gas pipelines is achieved, which has the advantages of high reliability, strong pressure resistance, and safety redundancy, significantly improving the safety of maintenance operations.

Description

Technical Field

[0001] This invention relates to the field of safety isolation technology for large-diameter gas pipelines in the industrial, commercial, and metallurgical sectors, and in particular to an effective isolation method for large-diameter gas recovery systems based on liquid seal balance. Background Technology

[0002] In integrated industrial and metallurgical enterprises, the gas recovery system is a core component for energy efficiency and green production. Large quantities of combustible gas generated during blast furnace and converter smelting processes must be transported to gas holders via main pipelines with diameters of 1.6-2.2 meters for use in waste heat power generation, sintering machine baking, ladle refining, and other production processes. During maintenance of gas holders, downstream pipelines, and auxiliary equipment, the upstream gas source must be completely isolated to prevent gas leaks that could lead to explosions, poisoning, or other major safety accidents, ensuring the safety of maintenance operations.

[0003] In existing technologies, mechanical valves such as butterfly valves and gate valves are mostly used for shut-off of small-diameter gas pipelines (≤1.2m). However, when these valves are applied to large-diameter gas pipelines with a diameter ≥1.6m, the following drawbacks exist:

[0004] 1. Insufficient sealing reliability: The machining precision of the sealing surface of large-diameter mechanical valves is difficult to guarantee. Impurities such as tar, coke dust, and pipeline corrosion products carried in the gas are easy to adhere to the sealing surface, forming tiny gaps, which makes it impossible for the valve to achieve zero leakage sealing. In addition, the valve stem of large-diameter valves is subjected to uneven force. After long-term start-stop operation, the sealing parts are prone to aging, deformation, and wear, which further reduces the isolation effectiveness and forms a "hidden leakage channel".

[0005] 2. Poor pressure adaptability: The gas transmission pressure of blast furnace and converter is relatively high. The valve body structure strength and sealing pressure resistance of large-diameter mechanical valves are difficult to match the pressure level for a long time, which can easily lead to problems such as valve body leakage and valve stem seal failure.

[0006] 3. Lack of safety redundancy design: The single mechanical valve has no backup isolation mechanism. Once a fault such as valve jamming or seal failure occurs, it cannot quickly respond to block the gas, which brings extremely high safety risks to the maintenance area.

[0007] 4. High operation and maintenance costs and impact on production: Large-diameter mechanical valves are bulky and complex in structure. Installation and disassembly require large lifting equipment. Routine maintenance requires regular disassembly and repair of seals. The maintenance cycle is long and costly. Moreover, the maintenance process requires downtime, which seriously affects the continuity of production.

[0008] 5. Poor adaptability to operating conditions: The medium in gas pipelines has a complex composition and large temperature fluctuations. The metal seals of mechanical valves are susceptible to corrosion and coking. Under harsh operating conditions such as low temperature and high humidity, the sealing performance deteriorates rapidly, further shortening the service life.

[0009] The aforementioned defects mean that existing mechanical valve isolation technology is completely unable to meet the safety isolation requirements during the maintenance of large-diameter gas recovery systems, and there is an urgent need for a new isolation technology solution with high reliability, strong pressure resistance, and safety redundancy. Summary of the Invention

[0010] To overcome the aforementioned shortcomings of the prior art, this invention provides an effective isolation method for a large-diameter gas recovery system based on liquid seal balance, aiming to provide an effective isolation method for a large-diameter gas recovery system based on liquid seal balance with high reliability, strong pressure resistance, and safety redundancy.

[0011] The technical solution adopted by this invention to solve its technical problem is: an effective isolation method for a large-diameter gas recovery system based on liquid seal balance, comprising the following steps:

[0012] Step 1: Install a U-shaped bend pipe with the same diameter as the main gas pipeline as the main water seal body;

[0013] Step 2: Install a water supply device on the upper part of one side of the U-shaped bend pipe, install a liquid level observation device in the middle of the other side of the U-shaped bend pipe, and install a drain pipe at the bottom of the U-shaped bend pipe; the drain pipe is used to drain the water accumulated in the U-shaped bend pipe.

[0014] Step 3: Inject clean water into the U-shaped bend pipe to the effective height to form a liquid seal barrier, so that the gas side pressure is balanced with the static pressure of the water column in the water seal body;

[0015] Step 4: During maintenance, the water level loss is dynamically replenished through the water replenishment device to maintain a stable water seal level;

[0016] Step 5: After the maintenance is completed, close the valve connecting the U-shaped bend pipe to the main gas pipeline, open the drain pipe at the bottom of the U-shaped bend pipe to drain the water inside the U-shaped bend pipe, and remove the barrier.

[0017] As a further improvement of the present invention: a gas drainer is provided at the bottom of the U-shaped bend pipe. The gas drainer is used to discharge deposited tar, dust and other impurities to avoid blockage and affect the water seal effect.

[0018] As a further improvement of the present invention: in step three, the effective height is designed according to "1m water level corresponds to 10kPa gas pressure", and a 10% safety margin is reserved.

[0019] As a further improvement of the present invention, the U-shaped bend pipe is made of Q235B carbon steel. By using Q235B carbon steel for the U-shaped bend pipe, the water seal body possesses good structural strength and weldability, enabling it to stably bear the mechanical load of large-diameter gas main pipelines during operation and maintenance. Simultaneously, Q235B carbon steel exhibits good corrosion resistance in the corrosive environments commonly found in gas media, effectively extending the service life of the water seal body.

[0020] As a further improvement of the present invention, the water replenishment pipe is a DN50 seamless steel pipe. By using a DN50 seamless steel pipe for the water replenishment pipe, the water replenishment device has sufficient flow capacity and can quickly respond to water level replenishment needs. At the same time, the seamless steel pipe's weld-free structure effectively avoids the risk of leakage caused by defects in the pipe itself during the water replenishment process.

[0021] As a further improvement of the present invention, the water replenishment device includes a water replenishment pipe and a manual valve. By including the water replenishment pipe and the manual valve, the operator can independently control the amount and timing of water replenishment based on the observed liquid level, thereby achieving precise adjustment of the water level in the water seal body.

[0022] As a further improvement of the present invention, the liquid level observation component is a glass tube level gauge. By setting the liquid level observation component to a glass tube level gauge, on-site personnel can intuitively and in real time observe the water level height inside the U-shaped bend pipe, facilitating timely detection of water level drops and intervention.

[0023] As a further improvement of the present invention, a pipe support is provided at the bottom of the U-shaped bend pipe. By providing a pipe support at the bottom of the U-shaped bend pipe, the water seal body maintains a stable supporting state during operation.

[0024] As a further improvement of the present invention, the drain pipe is equipped with a drain valve. By providing a drain valve to the drain pipe, the accumulated water in the U-shaped bend pipe can be easily drained after maintenance, thus achieving rapid release of the isolation state.

[0025] As a further improvement of the present invention, both the gas drainer and the drain pipe are located at the lowest point of the U-shaped bend pipe. By concentrating the gas drainer and the drain pipe at the lowest point of the U-shaped bend pipe, the deposited tar, dust, and other impurities can naturally collect to the drain outlet by gravity, achieving efficient and thorough impurity discharge. This effectively prevents impurities from accumulating inside the U-shaped bend pipe and affecting the water seal effect. It also facilitates the drainage of accumulated water after maintenance, improving the convenience and thoroughness of the isolation removal operation.

[0026] Compared with the prior art, the beneficial effects of the present invention are:

[0027] 1. This invention uses a U-shaped bend pipe with the same diameter as the main gas pipeline as the water seal body, enabling the liquid seal structure to adapt to large-diameter pipelines and avoiding additional resistance or leakage risks caused by changes in pipe diameter. By installing a water replenishment device on the upper part of one riser of the U-shaped bend pipe and a liquid level observation component in the middle of the other riser, dynamic monitoring and timely replenishment of the water seal level are achieved, ensuring that the effective water seal height continuously meets design requirements and preventing "seal detachment" due to water level drops. A drain pipe is installed to drain accumulated water after maintenance, facilitating quick disconnection. By replacing traditional mechanical valves with a liquid seal, zero-leakage isolation of large-diameter gas pipelines is achieved, offering advantages such as high reliability, strong pressure resistance, and safety redundancy, significantly improving the safety of maintenance operations.

[0028] 2. This invention uses a gas drainer installed at the bottom of the U-shaped bend pipe to periodically discharge deposited tar, dust and other impurities, effectively preventing impurities from clogging the water seal and ensuring the continuous reliability of the partition.

[0029] 3. By designing the effective height according to "1m water level corresponds to 10kPa gas pressure", this invention enables the liquid seal height of the water seal body to be precisely matched with the actual pressure in the main gas pipeline, ensuring the reliability of the partition. By reserving a 10% safety margin, the water seal body can effectively cope with gas pressure fluctuations and avoid "unsealing" caused by instantaneous pressure increases, further enhancing the safety of the partition. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the structure of the present invention.

[0031] Reference numerals: 1. U-shaped bend pipe; 2. Water supply device; 3. Liquid level observation component; 4. Gas drainer; 5. Drain pipe; 6. Pipe support. Detailed Implementation

[0032] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the present invention will be briefly introduced below in conjunction with the accompanying drawings and descriptions of the embodiments or the prior art. Obviously, the following description of the structure of the accompanying drawings is only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. It should be noted that the description of these embodiments is for the purpose of helping to understand the present invention, but does not constitute a limitation of the present invention.

[0033] It should be understood that the terms “comprising” and “having”, and any variations thereof, are intended to cover non-exclusive inclusion, for example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or device.

[0034] It should be understood that although the terms first, second, etc., may be used herein to describe various units, these units should not be limited by these terms. These terms are only used to distinguish one unit from another. For example, a first unit may be referred to as a second unit, and similarly, a second unit may be referred to as a first unit, without departing from the scope of the exemplary embodiments of the invention.

[0035] It should be understood that the term "and / or" that may appear in this document is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can mean: A exists alone, B exists alone, and A and B exist simultaneously. The term " / and" that may appear in this document describes another relationship between related objects, indicating that two relationships can exist. For example, A / and B can mean: A exists alone, and A and B exist alone. In addition, the character " / " that may appear in this document generally indicates that the related objects before and after it are in an "or" relationship.

[0036] It should be understood that specific details are provided in the following description to facilitate a complete understanding of the exemplary embodiments. However, those skilled in the art will understand that the exemplary embodiments can be implemented without these specific details. For example, the system may be shown in block diagrams to avoid obscuring the example with unnecessary details. In other instances, well-known processes, structures, and techniques may be shown without unnecessary details to avoid obscuring the exemplary embodiments.

[0037] Please see Figure 1 An effective isolation method for a large-diameter gas recovery system based on liquid seal balance includes the following steps:

[0038] Step 1: Install a U-shaped bend pipe 1 with the same diameter as the main gas pipeline as the main water seal body;

[0039] Step 2: Install a water supply device 2 on the upper part of one side of the riser of the U-shaped bend pipe 1, install a liquid level observation component 3 in the middle of the other side of the riser of the U-shaped bend pipe 1, and install a drain pipe 5 at the bottom of the U-shaped bend pipe 1; the drain pipe 5 is used to drain the water accumulated in the U-shaped bend pipe 1.

[0040] Step 3: Inject clean water into the U-shaped bend pipe 1 to the effective height to form a liquid seal barrier, so that the gas side pressure is balanced with the static pressure of the water column of the water seal body;

[0041] Step 4: During maintenance, the water level loss is dynamically replenished through the water replenishment device 2 to maintain a stable water seal level;

[0042] Step 5: After the maintenance is completed, close the valve connecting the U-shaped bend pipe 1 to the main gas pipeline, open the drain pipe 5 at the bottom of the U-shaped bend pipe 1 to drain the water inside the U-shaped bend pipe 1, and remove the isolation.

[0043] By using a U-shaped bend pipe 1 with the same diameter as the main gas pipeline as the water seal body, the liquid seal structure can be adapted to large-diameter pipelines, avoiding additional resistance or leakage risks caused by changes in pipe diameter. A water replenishment device 2 is installed on the upper part of one riser of the U-shaped bend pipe 1, and a liquid level observation component 3 is installed in the middle of the other riser, enabling dynamic monitoring and timely replenishment of the water seal level. This ensures that the effective water seal height continuously meets design requirements and prevents "seal detachment" due to water level drops. A drain pipe 5 is installed to drain accumulated water after maintenance, facilitating quick disconnection. By replacing traditional mechanical valves with a liquid seal, zero-leakage isolation of large-diameter gas pipelines is achieved, offering advantages such as high reliability, strong pressure resistance, and safety redundancy, significantly improving the safety of maintenance operations.

[0044] In some embodiments, a gas drainer 4 is provided at the bottom of the U-shaped bend pipe 1. The gas drainer 4 is used to drain impurities such as tar, dust, and water deposited during the production process to avoid clogging and affecting the water seal effect.

[0045] By installing a gas drainer 4 at the bottom of the U-shaped bend pipe 1, deposited tar, dust, water and other impurities can be discharged regularly during the production process, effectively preventing impurities from clogging and affecting the water seal effect, and ensuring the continuous reliability of the partition.

[0046] In some implementations, in step three, the effective height is designed according to the principle of "1m water level corresponds to 10kPa gas pressure", with a 10% safety margin reserved.

[0047] By designing the effective height according to the principle of "1m water level corresponds to 10kPa gas pressure", the liquid seal height of the water seal body is precisely matched with the actual pressure in the main gas pipeline, ensuring the reliability of the partition. By reserving a 10% safety margin, the water seal body can effectively cope with gas pressure fluctuations and avoid "unsealing" caused by instantaneous pressure increases, further enhancing the safety of the partition.

[0048] In some embodiments, the U-shaped bend pipe 1 is made of Q235B carbon steel.

[0049] The U-shaped bend pipe 1 is made of Q235B carbon steel, which gives the water seal body good structural strength and welding performance. It can stably bear the mechanical load of large-diameter gas main pipelines during operation and maintenance. At the same time, Q235B carbon steel exhibits good corrosion resistance in the corrosive environment commonly found in gas media, effectively extending the service life of the water seal body and reducing the risk of leakage caused by pipeline corrosion.

[0050] In some embodiments, the water supply pipe is a DN50 seamless steel pipe.

[0051] By using DN50 seamless steel pipes for the water replenishment pipeline, the water replenishment device 2 has sufficient flow capacity to quickly respond to water replenishment needs. At the same time, the seamless steel pipe's weld-free structure effectively avoids leakage risks caused by defects in the pipe itself during the water replenishment process, thus improving the overall reliability of the water replenishment system.

[0052] In some embodiments, the water replenishment device 2 includes a water replenishment pipe and a manual valve.

[0053] The water replenishment device 2, including a water replenishment pipe and a manual valve, allows operators to independently control the amount and timing of water replenishment based on the observed liquid level, thereby achieving precise adjustment of the water level of the water seal body and avoiding the impact of excessive or insufficient water replenishment on the isolation effect.

[0054] In some embodiments, the liquid level observation component 3 is a glass tube liquid level gauge.

[0055] By setting the liquid level observation component 3 as a glass tube liquid level gauge, on-site personnel can intuitively and in real time observe the water level height in the U-shaped bend pipe 1, which facilitates timely detection of water level drop and intervention, ensuring that the effective height of the water seal is always within the design range.

[0056] In some embodiments, a pipe support 6 is provided at the bottom of the U-shaped bend pipe 1.

[0057] By setting a pipe support 6 at the bottom of the U-shaped bend pipe 1, the water seal body can maintain a stable support state during operation, ensuring the stability of the liquid seal interface.

[0058] In some embodiments, the drain pipe 5 is equipped with a drain valve.

[0059] By installing a drain valve on drain pipe 5, the water accumulated in U-shaped bend pipe 1 can be easily drained after maintenance, thus quickly releasing the isolation state and facilitating the cleaning of the water seal during routine maintenance.

[0060] In some embodiments, the diameter of the main gas pipeline is ≥1.6m.

[0061] The U-shaped bend pipe 1 of the present invention can be applied to gas main pipelines with a diameter ≥ 1.6m. By using a U-shaped bend pipe 1 with the same diameter as the gas main pipeline as the water seal body, there is no need to change the pipe diameter, avoiding the additional resistance and potential leakage risk caused by the change of pipe diameter, and ensuring good compatibility between the liquid seal structure and the existing gas pipeline network.

[0062] In some embodiments, both the gas drainer 4 and the drain pipe 5 are located at the lowest point of the bottom of the U-shaped bend pipe 1.

[0063] By concentrating the gas drainer 4 and drain pipe 5 at the lowest point of the U-shaped bend pipe 1, the deposited tar, dust and other impurities can be naturally collected to the drain outlet by gravity, achieving efficient and thorough impurity discharge. This effectively prevents impurities from accumulating in the U-shaped bend pipe 1 and affecting the water seal effect. At the same time, it facilitates the drainage of accumulated water after maintenance, improves the convenience and thoroughness of the isolation removal operation, and further enhances the safety of maintenance operations for large-diameter gas recovery systems.

[0064] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.

Claims

1. An effective isolation method for a large-diameter gas recovery system based on liquid seal balance, characterized in that: Includes the following steps: Step 1: Install a U-shaped bend pipe with the same diameter as the main gas pipeline as the main water seal body; Step 2: Install a water supply device on the upper part of one side of the U-shaped bend pipe, install a liquid level observation device in the middle of the other side of the U-shaped bend pipe, and install a drain pipe at the bottom of the U-shaped bend pipe; Step 3: Inject clean water into the U-shaped bend pipe to the effective height to form a liquid seal barrier; Step 4: During maintenance, dynamically replenish the water level loss using a water replenishment device; Step 5: After the maintenance is completed, close the valve connecting the U-shaped bend pipe to the main gas pipeline, open the drain pipe at the bottom of the U-shaped bend pipe to drain the water inside the U-shaped bend pipe, and remove the barrier.

2. The effective isolation method for a large-diameter gas recovery system based on liquid seal balance according to claim 1, characterized in that: A gas drain is installed at the bottom of the U-shaped bend pipe.

3. The effective isolation method for a large-diameter gas recovery system based on liquid seal balance according to claim 1, characterized in that: In step three, the effective height is designed according to the principle of "1m water level corresponds to 10kPa gas pressure", with a 10% safety margin reserved.

4. The effective isolation method for a large-diameter gas recovery system based on liquid seal balance according to claim 1, characterized in that: The U-shaped bend pipe is made of Q235B carbon steel.

5. The effective isolation method for a large-diameter gas recovery system based on liquid seal balance according to claim 1, characterized in that: The water supply pipe is a DN50 seamless steel pipe.

6. The effective isolation method for a large-diameter gas recovery system based on liquid seal balance according to claim 1, characterized in that: The water replenishment device includes a water replenishment pipe and a manual valve.

7. The effective isolation method for a large-diameter gas recovery system based on liquid seal balance according to claim 1, characterized in that: The liquid level observation component is a glass tube liquid level gauge.

8. The effective isolation method for a large-diameter gas recovery system based on liquid seal balance according to claim 1, characterized in that: The bottom of the U-shaped bend pipe is provided with a pipe support.

9. The effective isolation method for a large-diameter gas recovery system based on liquid seal balance according to claim 1, characterized in that: The drain pipe is equipped with a drain valve.

10. The effective isolation method for a large-diameter gas recovery system based on liquid seal balance according to claim 2, characterized in that: The gas drainer and drain pipe are both located at the lowest point of the bottom of the U-shaped bend pipe.

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