Replaceable sorbent double-walled tube

Abstract

The application discloses a replaceable adsorbent double-wall tube, which comprises an inner tube, an outer tube and two partitions. The outer diameter of the inner tube is smaller than the inner diameter of the outer tube. The inner tube is coaxially arranged with the outer tube. The partition is annular and comprises an inner edge and an outer edge. The inner edge is connected with the outer wall of the inner tube, and the outer edge is connected with the inner wall of the outer tube, so that the inner tube, the outer tube and the two partitions can surround a closed cavity. The replaceable adsorbent double-wall tube further comprises two vacuum joints which are connected with the cavity. The replaceable adsorbent double-wall tube has the advantages that the adsorbent can be recycled, the use cost is reduced, the adsorbent can be refilled, and the double-wall tube can keep a vacuum state for a long time.

Description

Technical Field

[0001] This invention relates to a double-walled tube, and more specifically, a double-walled tube with a replaceable adsorbent. Background Technology

[0002] Natural gas, as a clean energy source, is increasingly used as fuel for ship engines. However, gaseous natural gas occupies a large amount of space, making it inconvenient to transport and store. Therefore, it is usually liquefied into liquefied natural gas (LNG) through pressurization and cooling, and stored in tanks. However, LNG tanks are typically located in the middle of the ship, while the refueling connection is usually located at the bow. Therefore, a long pipeline is required between the refueling connection and the LNG tank. Furthermore, there is a considerable distance between the LNG tank and the ship's natural gas engine, necessitating a long pipeline between them. Since LNG is typically cold, double-walled pipes are often used to transport it to prevent significant heat loss through the pipelines. Common double-walled pipes consist of an inner and outer tube made of seamless steel, with a vacuum cavity between them. This vacuum cavity effectively blocks convective heat transfer between the inner and outer tubes. However, the small hydrogen molecules contained between the metal crystals of seamless steel pipes will gradually escape into the vacuum cavity over time, affecting the vacuum level and heat insulation effect of the cavity. Therefore, the cavity of this structure needs to be evacuated regularly, which results in higher operating costs.

[0003] To address the aforementioned issue of needing to periodically evacuate, Chinese invention patent application CN113819316A discloses a high-vacuum integral adsorption-type insulated double-walled tube. An adsorption box is arranged within its cavity, containing a vacuum adsorbent. This adsorbent adsorbs hydrogen gas escaping from the metal crystals, maintaining a high vacuum state in the cavity and avoiding frequent evacuation. However, palladium oxide, commonly used as an adsorbent for hydrogen adsorption, is expensive, leading to high production costs for this double-walled tube. Furthermore, once palladium oxide is saturated with hydrogen, it can no longer adsorb hydrogen gas escaping from the metal crystals. Therefore, to maintain a high vacuum in the cavity thereafter, periodic evacuation is still necessary, resulting in continued high operating costs. Summary of the Invention

[0004] The present invention mainly addresses the technical problems existing in the prior art, thereby providing a replaceable adsorbent double-walled tube that can recover the adsorbent, thus reducing the cost of use, and can be refilled with adsorbent, allowing the double-walled tube to maintain a vacuum state for a long time.

[0005] The present invention solves the technical problems existing in the prior art through the following technical solution:

[0006] A replaceable adsorbent double-walled tube includes an inner tube, an outer tube, and two partitions. The outer diameter of the inner tube is smaller than the inner diameter of the outer tube. The inner tube and the outer tube are arranged coaxially. The partitions are annular structures including an inner edge and an outer edge. The inner edge is connected to the outer wall of the inner tube, and the outer edge is connected to the inner wall of the outer tube, so that the inner tube, the outer tube, and the two partitions can surround and form a sealed cavity. The replaceable adsorbent double-walled tube also includes two vacuum connectors. The two vacuum connectors are connected to the cavity. Through the vacuum connectors, gas and adsorbent powder can be injected into the cavity or gas can be extracted from the cavity and the adsorbent powder can be removed from the cavity, while simultaneously bringing the cavity to a vacuum state.

[0007] As a preferred technical solution of the present invention, the two partitions are arranged at an inclination relative to the axial direction of the double-walled tube, so that the cavity has two "V"-shaped ends, and the two vacuum connectors are each connected to one of the "V"-shaped ends.

[0008] As a preferred technical solution of the present invention, the two partitions are arranged in parallel to each other.

[0009] As a preferred technical solution of the present invention, the double-walled tube with replaceable adsorbent further includes a sliding sleeve, which is sleeved on the inner tube. The inner wall of the sliding sleeve is in contact with the outer wall of the inner tube, and the outer wall of the sliding sleeve is in contact with the inner wall of the outer tube. The sliding sleeve can slide along the axial direction of the inner tube.

[0010] As a preferred technical solution of the present invention, the sliding sleeve is a cylindrical helical spring-shaped structure.

[0011] As a preferred technical solution of the present invention, the pitch h of the cylindrical helical spring structure is greater than twice the diameter d of the steel wire.

[0012] As a preferred technical solution of the present invention, the vacuum connector is further threadedly connected to an adsorbent filling chamber.

[0013] As a preferred technical solution of the present invention, the adsorbent powder is palladium oxide powder.

[0014] The advantages of the replaceable adsorbent double-walled tube of the present invention are: the adsorbent can be recovered, thereby helping to reduce the cost of use, and the adsorbent can be refilled, so that the double-walled tube can maintain a vacuum state for a long time. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are 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.

[0016] Figure 1 This is a schematic diagram of the double-walled tube with replaceable adsorbent of the present invention;

[0017] Figure 2 This is a schematic diagram of the partition in the double-walled tube with replaceable adsorbent of the present invention.

[0018] in:

[0019] 1. Inner tube;

[0020] 2. Outer tube;

[0021] 3. Partition; 31. Inner edge; 32. Outer edge;

[0022] 4. Vacuum connector; 41. Adsorbent filling chamber;

[0023] 5. Cavity;

[0024] 6. Sliding sleeve. Detailed Implementation

[0025] The preferred embodiments of the present invention will be described in detail below so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more explicit definition of the scope of protection of the present invention.

[0026] The advantages of the replaceable adsorbent double-walled tube of the present invention are: the adsorbent can be recovered, thereby helping to reduce the cost of use, and the adsorbent can be refilled, so that the double-walled tube can maintain a vacuum state for a long time.

[0027] like Figure 1 As shown, a double-walled tube with replaceable adsorbent includes an inner tube 1, an outer tube 2, and two baffles 3. The outer diameter of the inner tube 1 is smaller than the inner diameter of the outer tube 2. The inner tube 1 and the outer tube 2 are arranged coaxially. Figure 2As shown, the partition 3 is an annular structure including an inner edge 31 and an outer edge 32. The inner edge 31 is connected to the outer wall of the inner tube 1, and the outer edge 32 is connected to the inner wall of the outer tube 2, so that the inner tube 1, the outer tube 2 and the two partitions 3 can surround and form a sealed cavity 5. The double-walled tube with replaceable adsorbent also includes two vacuum connectors 4, which are connected to the cavity 5. Through the vacuum connectors 4, gas and adsorbent powder can be injected into the cavity 5 or gas can be extracted from the cavity 5 and the adsorbent powder in the cavity 5 can be removed, so that the cavity 5 reaches a vacuum state.

[0028] The method for adding adsorbent powder for hydrogen adsorption into the cavity 5 is as follows: the adsorbent powder is mixed with dry nitrogen and injected into the cavity 5 through the vacuum connector 4. The double-walled tube with replaceable adsorbent is left to stand for a period of time until the adsorbent powder in the cavity 5 settles. Then, the nitrogen in the cavity 5 is removed through the vacuum connector 4 to achieve a high vacuum state in the cavity 5, thereby achieving a better heat insulation effect.

[0029] The method for recovering the adsorbent in the cavity 5 is as follows: Nitrogen gas is injected into the cavity 5 through a vacuum connector 4. After the nitrogen gas enters the cavity 5, it will blow up the adsorbent powder in the cavity 5. At the same time, the nitrogen gas mixed with adsorbent powder in the cavity 5 is extracted through another vacuum connector 4 and collected into a nitrogen collection container. The adsorbent powder can be separated by letting the nitrogen collection container stand.

[0030] The two baffles 3 are arranged at an angle relative to the axis of the double-walled tube, giving the cavity 5 two "V"-shaped ends. Each of the two vacuum connectors 4 is connected to one of these "V"-shaped ends. In common designs, the baffles 3 are arranged perpendicular to the axis of the double-walled tube. When recovering the adsorbent powder, after nitrogen gas is injected into the cavity 5 through one vacuum connector 4, the adsorbent powder does not easily accumulate near the other vacuum connector 4, resulting in incomplete recovery. In this invention, by arranging the baffles 3 at an angle, the cavity 5 has two "V"-shaped ends. Each of the two vacuum connectors 4 is connected to one of these "V"-shaped ends. When nitrogen gas is injected into the cavity 5 through one vacuum connector 4, the adsorbent powder easily collects and is discharged at the other vacuum connector 4 with the gas flow, thus facilitating complete recovery of the adsorbent powder.

[0031] The two partitions 3 are arranged in parallel to each other. When the double-walled tube with replaceable adsorbent is arranged horizontally, one of the vacuum connectors 4 can be arranged downwards and the other vacuum connector 4 can be arranged upwards. When nitrogen mixed with adsorbent powder is added to the cavity 5, the area near the upward-arranged vacuum connector 4 will not be covered by deposited adsorbent powder, thus avoiding the newly injected adsorbent powder being extracted again and wasted.

[0032] The replaceable adsorbent double-walled tube also includes a sliding sleeve 6, which is fitted onto the inner tube 1. The inner wall of the sliding sleeve 6 contacts the outer wall of the inner tube 1, and the outer wall of the sliding sleeve 6 contacts the inner wall of the outer tube 2. The sliding sleeve 6 can slide along the axial direction of the inner tube 1. The adsorbent powder is relatively fine and is prone to caking after adsorbing gas, adsorbing onto the inner wall of the cavity. It is difficult to completely clean the adsorbent powder adhering to the inner wall of the cavity 5 by simply injecting airflow into the cavity 5. By setting the sliding sleeve 6, after injecting a certain amount of nitrogen through a vacuum connector 4, the sliding sleeve 6 can be moved to scrape off the powder adsorbed on the inner wall of the cavity 5. At the same time, it can also break up the caking blocky adsorbent, so that the adsorbent can be completely discharged from the cavity 5.

[0033] The sliding sleeve 6 has a cylindrical helical spring structure. Since the sliding sleeve 6 contacts both the inner tube 1 and the outer tube 2, it easily transfers heat between them, worsening the insulation effect of the double-walled tube with replaceable adsorbent. Designing the sliding sleeve 6 as a spring structure increases its thermal resistance with both the inner tube 1 and the outer tube 2, thereby improving the insulation effect of the double-walled tube with replaceable adsorbent. Furthermore, it still effectively scrapes off adsorbent powder and breaks up clumps of adsorbent.

[0034] like Figure 1 As shown, the pitch h of the cylindrical helical spring structure is greater than twice the diameter d of the steel wire. This design allows airflow to still pass through when the sleeve 6 is accidentally jammed and fixed in a certain position inside the cavity 5, thanks to the gap between two adjacent steel wire sections. This enables the adsorbent powder to be replaced smoothly, although there may be a problem of incomplete adsorbent recovery in this case. However, the adsorbent can still be replaced without the need for periodic vacuuming.

[0035] The vacuum connector 4 is also threadedly connected to an adsorbent filling chamber 41. The adsorbent powder is palladium oxide powder. When filling the cavity 5 with palladium oxide powder, the palladium oxide powder can be placed in the adsorbent filling chamber 41 first, and then nitrogen gas can be added to the cavity 5 through the vacuum connector 4. When the nitrogen gas flows through the vacuum connector 4, the palladium oxide powder in the adsorbent filling chamber 41 can enter the cavity 5 with the gas flow, thus achieving the purpose of adding palladium oxide powder.

[0036] The above are merely some of the design ideas for the embodiments of the present invention. Where the system allows, the present invention can be extended to simultaneously connect more functional modules, thereby maximizing its functionality.

[0037] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions conceived without inventive effort should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A double-walled tube with replaceable adsorbent, comprising an inner tube (1), an outer tube (2), and two partitions (3), wherein the outer diameter of the inner tube (1) is smaller than the inner diameter of the outer tube (2), the inner tube (1) and the outer tube (2) are coaxially arranged, and the partitions (3) are annular structures comprising an inner edge (31) and an outer edge (32), wherein the inner edge (31) is connected to the outer wall of the inner tube (1), and the outer edge (32) is connected to the inner wall of the outer tube (2), such that the inner tube (1), the outer tube (2), and the two partitions (3) can surround and form a sealed cavity (5), characterized in that: The replaceable adsorbent double-walled tube also includes two vacuum connectors (4), which are connected to the cavity (5); Method for adding adsorbent powder to the cavity (5): Gas mixed with adsorbent powder can be injected into the cavity (5) through the vacuum connector (4). After the adsorbent powder in the cavity (5) settles, the gas in the cavity (5) is extracted through the vacuum connector (4) to make the cavity (5) reach a vacuum state. Method for recovering adsorbent powder from cavity (5): Gas is injected into cavity (5) through one of the vacuum connectors (4). The gas entering cavity (5) blows up the adsorbent powder, while the gas mixed with adsorbent powder in cavity (5) is extracted through another vacuum connector (4).

2. The double-walled tube with replaceable adsorbent according to claim 1, characterized in that: The two partitions (3) are arranged at an angle relative to the axis of the double-walled tube, so that the cavity (5) has two "V" shaped ends, and the two vacuum connectors (4) are each connected to one of the "V" shaped ends.

3. The double-walled tube with replaceable adsorbent according to claim 2, characterized in that: The two partitions (3) are arranged in parallel to each other.

4. The double-walled tube with replaceable adsorbent according to claim 1, characterized in that: The replaceable adsorbent double-walled tube further includes a sliding sleeve (6), which is sleeved on the inner tube (1). The inner wall of the sliding sleeve (6) is in contact with the outer wall of the inner tube (1), and the outer wall of the sliding sleeve (6) is in contact with the inner wall of the outer tube (2). The sliding sleeve (6) can slide along the axial direction of the inner tube (1).

5. The double-walled tube with replaceable adsorbent according to claim 4, characterized in that: The sliding sleeve (6) is a cylindrical helical spring structure.

6. The double-walled tube with replaceable adsorbent according to claim 5, characterized in that: The pitch h of the cylindrical helical spring structure is greater than twice the diameter d of the steel wire.

7. The double-walled tube with replaceable adsorbent according to claim 1, characterized in that: The vacuum connector (4) is also threadedly connected to an adsorbent filling chamber (41).

8. The double-walled tube with replaceable adsorbent according to claim 1, characterized in that: The adsorbent powder is palladium oxide powder.

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