Gas collecting device

Abstract

The utility model provides a gas collecting device which comprises a collector, a retaining plug, a gas volume measuring device and an experiment cup, and the collector comprises a top cover, a gas collecting part and a support; the top cover covers a cup opening of the experiment cup, and the gas collecting part is installed at the bottom of the top cover through a support and located in the experiment cup; the retaining plug is clamped in a gap in the middle of the top cover, the gas volume measuring device is arranged in an axial channel in the middle of the retaining plug, the top end of the gas volume measuring device extends outwards, and the bottom end of the gas volume measuring device is communicated with an extending pipe arranged at the top of the gas collecting part. The gas collecting part and the experiment cup are fixed through the support and the top cover, the problem that the solution solute exchange rate is reduced due to the fact that the bottom of the gas collecting part and the bottom of the experiment cup form a closed space is avoided, and meanwhile the gas volume measuring device is fixed in the top cover through the retaining plug. And the problem of shaking of the gas volume measuring device during gas collection is avoided.

Description

Technical Field

[0001] This utility model relates to the field of material performance testing technology, specifically to a gas collection device. Background Technology

[0002] Biodegradable materials, especially magnesium and magnesium alloys, generally refer to materials that can degrade in vivo, producing harmless or essentially harmless degradation products. Their corrosion and degradation within the body can avoid secondary surgeries and reduce the burden on patients. However, current research indicates that biodegradable materials corrode too rapidly during implantation, leading to failure within the effective fixation period. Therefore, a performance testing method is needed to monitor the corrosion and degradation rate of biodegradable materials in simulated in vitro bodily fluids, providing an analogy and reference for in vivo corrosion.

[0003] Common methods for testing the in vitro degradation performance of biodegradable magnesium metal include the weight loss method, the hydrogen evolution method, and the electrochemical method. The hydrogen evolution method involves collecting hydrogen gas generated from the reaction of a magnesium metal sample with SBF (sulfate-containing body fluid) in vitro. The mass of magnesium involved in the reaction is then calculated using the chemical reaction equation, thus determining the in vitro degradation rate of the magnesium metal sample. As an important in vitro degradation rate detection method, the hydrogen evolution method effectively overcomes the limitation of the weight loss method, which is only applicable to bare metals and not to surface-treated magnesium products, playing a crucial role in scientific research and quality control.

[0004] The hydrogen evolution method is suitable for detecting the degradation process of magnesium alloys or other biodegradable metals (by measuring gas evolution), or for detecting gas evolution in chemical reactions that generate gases. In addition, the aforementioned biodegradable materials are used in engineering fields such as automotive, aerospace, and construction. Corrosion and degradation under natural environments or various harsh working conditions can affect their performance. Therefore, the gas evolution method is also an important tool for studying these materials in scientific research and quality control.

[0005] In the hydrogen evolution test of the in vitro degradation performance of magnesium metal materials, gas collection is crucial. To effectively collect the insoluble gases generated during sample degradation, a gas collection hood needs to be suspended above the sample. For example... Figure 1As shown, in existing hydrogen evolution test methods, the inverted funnel acts as the gas collecting hood. To ensure that both the funnel and the gas volume measuring device (usually an inverted acid burette) are filled with solution before the test, and that the gas collected through the funnel ultimately enters the gas volume measuring device, the smaller end of the funnel must be inside the gas volume measuring device tube, while the opening of the gas volume measuring device tube must be below the liquid surface. This makes it difficult to suspend the funnel using a clamping system. Unless a dedicated support device is used, the funnel can only rest at the bottom of the experimental cup, forming a closed space with the bottom of the cup. The sample is placed inside the funnel, and the solution accessible to the sample (inside the inverted funnel) cannot exchange smoothly with the outside of the funnel. Since the solution volume is generally an important parameter in the experiment, the inverted funnel greatly slows down the exchange of solute in the solution, resulting in a reduction in the actual solution volume during the experiment, which affects the experimental results.

[0006] Inverted burettes (gas volume measuring devices) are generally quite long, which can cause them to wobble during gas collection. Furthermore, when multiple collection devices are used simultaneously, manual operation can lead to them being knocked over. Additionally, the complex assembly process results in low device stability and inaccurate centering. For example, when the funnel's centerline is tilted relative to the material, the reacted gas tends to accumulate on the tilted surface, leading to incomplete gas collection. Moreover, the aforementioned apparatus is an open-cup experiment; with the cup open, the solution continuously evaporates, causing its concentration to rise and directly affecting the experimental results. Utility Model Content

[0007] In view of the deficiencies in the prior art, the purpose of this utility model is to provide a gas collection device.

[0008] The gas collection device provided by this utility model includes a collector, a retaining plug, a gas volume measuring device, and an experimental cup. The collector includes a top cover, a gas collection part, and a support.

[0009] The top cover fits over the mouth of the experimental cup, and the gas collection part is installed at the bottom of the top cover via a bracket, with the gas collection part located inside the experimental cup;

[0010] The retaining plug is disposed in the gap in the middle of the top cover, and the retaining plug is provided with an axial channel. The gas volume measuring device is disposed in the axial channel, and the top end of the gas volume measuring device extends outward. The bottom end of the gas volume measuring device is connected to the protruding tube at the top of the gas collecting part.

[0011] Preferably, the gas collection section includes a gas collection surface and an extension pipe, the extension pipe being connected to the top of the gas collection surface;

[0012] The protruding tube is inserted into the bottom end of the gas volume measuring device, and the gas volume measuring device is connected to the bottom space of the gas collection surface through the protruding tube.

[0013] Preferably, the support is cylindrical, the top end of the support is connected to the inner edge of the gap in the middle of the top cover, and the bottom end of the support is located at the top of the gas collection section;

[0014] The bottom ends of the protruding tube and the gas volume measuring device are both located inside the cylindrical support. The support has through holes on its side wall, and the interior of the support is connected to the interior space of the experimental cup through the through holes.

[0015] Preferably, a groove is provided on the outer side of the bottom of the top cover, and the cup mouth end face of the experimental cup is installed in the groove;

[0016] The top cover, gas collection part and bracket are integrally formed or detachably connected, and the gas collection surface of the gas collection part is integrally formed or detachably connected to the extension tube.

[0017] Preferably, the through hole is located on the side wall of the support near the gas collection part, and multiple through holes are arranged along the circumference of the support, and the through hole is lower than the liquid level in the experimental bottle.

[0018] Preferably, the gas collecting surface has an inverted conical structure or an inverted regular pyramidal structure;

[0019] When the gas collection surface is an inverted cone structure, the vertex angle of the isosceles triangle of the axial section of the inverted cone structure ranges from 30° to 180°, and the ratio between the area of ​​the bottom circle of the inverted cone structure and the area of ​​the figure obtained by the intersection of the bottom circle of the inverted cone structure and the experimental bottle is 0.5 to 0.99.

[0020] When the gas collection surface is set as an inverted pyramid structure, the ratio between the area of ​​the regular polygon on the bottom surface of the inverted pyramid structure and the area of ​​the figure obtained by the intersection of the regular polygon on the bottom surface of the inverted pyramid structure and the experimental bottle is 0.4 to 0.98.

[0021] Preferably, the retaining plug comprises a frustum-shaped retaining plug.

[0022] Preferably, the experimental cup includes a cylindrical experimental cup, a cuboid experimental cup, a cube experimental cup, or a frustum-shaped experimental cup.

[0023] Preferably, the retaining plug is vertically inserted into the central gap of the collector, and the gas volume measuring device is vertically inserted into the axial channel of the retaining plug;

[0024] The top of the gas volume measuring device extends outward through an axial channel, while the bottom of the gas volume measuring device remains vertically positioned within the liquid surface of the experimental cup.

[0025] Preferably, the gas volume measuring device has a circular tube structure, the outer diameter of the gas volume measuring device is less than or equal to the inner diameter of the axial channel, and the inner diameter of the gas volume measuring device is greater than the outer diameter of the protruding tube.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] This invention has a simple structure and is easy to operate. The gas collection part is fixed on the experimental cup by the bracket and the top cover, which avoids the problem of the bottom of the gas collection part contacting the bottom of the experimental cup to form a closed space, which would slow down the solute exchange rate of the solution. At the same time, the gas volume measuring device is fixed in the top cover by the retaining plug, which avoids the problem of the gas volume measuring device shaking during gas collection. Attached Figure Description

[0028] Other features, objects, and advantages of this invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0029] Figure 1 This is a schematic diagram of the gas collection device in an existing hydrogen evolution test method;

[0030] Figure 2 This is a schematic diagram of the overall structure of this utility model.

[0031] The diagram shows:

[0032] Collector 1, Support 13

[0033] Top cover 11, through hole 131

[0034] Groove 111 Retaining plug 2

[0035] Gas collection section 12 Axial channel 21

[0036] Gas collection surface 121 Gas volume measuring device 3

[0037] Extended tube 122, experimental cup 4 Detailed Implementation

[0038] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the present invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0039] This utility model discloses a gas collection device. By replacing the inverted funnel in the traditional solution with a collector that integrates a top cover, a support, and a gas collection part, the gas collection part is installed on the top of the experimental cup. This avoids the problem of a closed space being formed between the gas collection part and the experimental cup, which would slow down the solution exchange rate. At the same time, the gas volume measuring device is fixed in the experimental cup by a retaining plug, which avoids the problem of the gas volume measuring device shaking during the collection process.

[0040] According to the gas collection device provided by this utility model, such as Figure 2 As shown, the apparatus includes a collector 1, a retaining plug 2, a gas volume measuring device 3, and an experimental cup 4. The collector 1 includes a top cover 11, a gas collecting part 12, and a support 13. The top cover 11 covers the mouth of the experimental cup 4. The gas collecting part 12 is installed at the bottom of the top cover 11 via the support 13 and is located inside the experimental cup 4. The retaining plug 2 is vertically inserted into the middle gap of the collector 1. The gas volume measuring device 3 is vertically inserted through the axial channel 21 of the retaining plug 2. The top end of the gas volume measuring device 3 extends outward from the axial channel 21 and is vertically positioned in the liquid surface inside the experimental cup 4.

[0041] Preferably, the raw materials for making the collector 1 are one or more of the following: glass, polytetrafluoroethylene, polymethyl methacrylate, fluorinated ethylene propylene copolymer, trifluorochloroethylene, polyphenylene sulfide, polyethylene, polypropylene, polyacrylamide, polyester resin, polystyrene, styrene-acrylonitrile copolymer, ethylene-vinyl acetate copolymer, polyvinyl chloride, acrylonitrile-styrene-butadiene copolymer, polycarbonate, and polyoxymethylene.

[0042] Furthermore, the gas collecting part 12 includes a gas collecting surface 121 and an extension pipe 122, the extension pipe 122 being connected to the top of the gas collecting surface 121; the extension pipe 122 is inserted into the bottom end of the gas volume measuring device 3, and the gas volume measuring device 3 is connected to the bottom space of the gas collecting surface 121 through the extension pipe 122. The gas volume measuring device 3 has a circular tube structure, the outer diameter of the gas volume measuring device 3 is less than or equal to the inner diameter of the axial channel 21, and the inner diameter of the gas volume measuring device 3 is greater than the outer diameter of the extension pipe 122.

[0043] The support 13 is cylindrical. The top end of the support 13 is connected to the inner edge of the gap in the middle of the top cover 11, and the bottom end of the support 13 is located at the top of the gas collection section 12. The bottom ends of the protruding tube 122 and the gas volume measuring device 3 are both located inside the cylindrical support 13. A through hole 131 is provided on the side wall of the support 13, and the interior of the support 13 communicates with the internal space of the experimental cup 4 through the through hole 131. Multiple through holes 131 are located on the side wall of the support 13 near the gas collection section 12, and each through hole 131 is lower than the liquid level inside the experimental bottle 4.

[0044] A groove 111 is provided on the outer side of the bottom of the top cover 11, and the cup mouth end face of the experimental cup 4 is installed in the groove 111. The top cover 11, the gas collection part 12, and the support 13 are integrally formed or detachably connected. The gas collection surface 121 of the gas collection part 12 is integrally formed or detachably connected to the extension tube 122. The retaining plug 2 includes a frustum-shaped retaining plug. The experimental cup 4 includes a cylindrical experimental cup, a cuboid experimental cup, a cube experimental cup, or a frustum-shaped experimental cup.

[0045] The gas collecting surface 121 has an inverted cone structure or an inverted regular pyramid structure. When the gas collecting surface 121 has an inverted cone structure, the vertex angle of the isosceles triangle of the axial section of the inverted cone structure ranges from 30° to 180°, and the ratio between the area of ​​the bottom circle of the inverted cone structure and the area of ​​the figure obtained by the intersection of the bottom circle of the inverted cone structure and the experimental bottle 4 is 0.5 to 0.99. When the gas collecting surface 121 is set as an inverted regular pyramid structure, the ratio between the area of ​​the regular polygon of the bottom surface of the inverted regular pyramid structure and the area of ​​the figure obtained by the intersection of the regular polygon of the bottom surface of the inverted regular pyramid structure and the experimental bottle 4 is 0.4 to 0.98.

[0046] Example 1

[0047] This embodiment provides a gas collection device, wherein the gas volume measuring device 3 is an inverted acid burette, with a model of 5ml to 10ml, and the experimental cup 4 is a cylindrical glass cup with a flat mouth, an inner diameter of 60mm to 70mm, and a total height of 120mm to 135mm. The top cover 11 is circular, with a groove 111 on its outer side, into which the end face of the experimental cup 4 can be placed. The gas collection part 12 and the support 13 are integrally formed and then assembled with the top cover 11 and fastened by threads. The gas collection surface 121 and the protruding tube 122 are integrally formed. Through holes 131 are provided on the side near the gas collection part 12, and six through holes 131 are arranged circumferentially along the inner wall of the support 13, each with a diameter of 3mm to 8mm. The liquid level in the experimental bottle 4 should be higher than the through holes 131. The raw material for the collector 1 is polytetrafluoroethylene. When the gas collecting surface 121 is configured as an inverted cone, the vertex angle of the isosceles triangle in the axial section of the inverted cone ranges from 55° to 75°, and the ratio of the area of ​​the inverted cone's base circle to the area of ​​the figure obtained by the intersection of the plane containing the inverted cone's base circle and the experimental bottle 4 is 0.75 to 0.95. The retaining plug 2 is a frustum-shaped retaining plug. The retaining plug 2 is vertically mounted on the collector 1, and one end of the gas volume measuring device 3 is vertically mounted on the retaining plug 2, while the other end of the gas volume measuring device 3 is vertically mounted in the liquid surface of the experimental cup 4 through the retaining plug 2.

[0048] EK30 magnesium alloy samples were soaked in Hank's solution for 10 days (with the solution changed every 2 days), and a total hydrogen gas volume of 1 ml to 3 ml was collected. The corrosion rate was calculated to be 0.03 mm / y to 0.10 mm / y. The gas collection device did not tip over during the process and would not tip over when touched. The solution was drawn out with a needle through the extension tube 122, and its pH was measured to be 7.80 to 8.02, which is basically consistent with the pH value of the solution after removing the collector 1 and mixing it (7.82 to 8.00).

[0049] Example 2

[0050] This embodiment provides a gas collection device, wherein the gas volume measuring device 3 is an inverted acid burette, with a size of 5ml to 10ml, and the experimental cup 4 is a cylindrical glass cup with a flat mouth, an inner diameter of 70mm to 80mm, and a total height of 140mm to 160mm. A groove 111 is provided on the outer side of the top cover 11, into which the end face of the experimental cup 4 can be placed. The top cover 11, the gas collection part 12, and the support 13 are integrally formed. The gas collection surface 121 and the extension tube 122 are integrally formed. Four through holes 131 are provided near the gas collection part 12, arranged circumferentially along the inner wall of the support 13, each with a diameter of 5mm to 10mm. The liquid level in the experimental bottle 4 should be higher than the through holes 131. The raw material for the collector 1 is polytetrafluoroethylene. When the gas collecting surface 121 is configured as an inverted cone, the vertex angle of the isosceles triangle in the axial section of the inverted cone ranges from 60° to 80°, and the ratio of the area of ​​the inverted cone's base circle to the area of ​​the figure obtained by the intersection of the plane containing the inverted cone's base circle and the experimental bottle 4 is 0.70 to 0.93. The retaining plug 2 is a frustum-shaped retaining plug. The retaining plug 2 is vertically mounted on the collector 1, and one end of the gas volume measuring device 3 is vertically mounted on the retaining plug 2, while the other end of the gas volume measuring device 3 is vertically mounted in the liquid surface of the experimental cup 4 through the retaining plug 2.

[0051] Pure magnesium samples were soaked in Hank's solution for 10 days (with the solution changed every 2 days), and the total volume of hydrogen gas collected ranged from 1.5 ml to 4.5 ml. The corrosion rate was calculated to be 0.05 mm / y to 0.14 mm / y. The gas collection device did not tip over during the process and was not tipped when touched. The solution was drawn out using a needle through the extension tube 122, and its pH was measured to be 7.95–8.23, which is basically consistent with the pH of the solution after removing and mixing from collector 1 (7.94–8.19).

[0052] Comparative Example 1

[0053] use Figure 1 The apparatus shown is used for the experiment. An inverted funnel is used as the collector, an inverted acid burette (5ml to 10ml) is used as the gas volume measuring device, and a cylindrical glass beaker with an inner diameter of 70mm to 80mm and a total height of 140mm to 160mm is used as the experimental beaker. The mouth of the beaker is covered with a plastic film with a hole in the middle. The acid burette passes through the hole in the film and is fixed to the funnel. The plastic film is fixed to the outer wall of the experimental beaker with a rubber band.

[0054] Pure magnesium samples were soaked in Hank's solution for 10 days (with the solution changed every 2 days), yielding a total hydrogen gas volume of 0.9 ml to 3 ml. The corrosion rate was calculated to be 0.03 mm / y to 0.10 mm / y. During the process, one of the five gas collection devices tipped over, requiring a fresh solution. Touching the gas collection device during solution changes could easily cause it to tip over, so extreme caution was required. The solution was drawn out through the bottom of an inverted funnel using a needle, and its pH was measured to be 8.10–8.33, which differed somewhat from the pH of the solution after mixing with the funnel (7.80–8.03).

[0055] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0056] The specific embodiments of this utility model have been described above. It should be understood that this utility model is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the substantive content of this utility model. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A gas collection device, characterized by, It comprises a collector (1), a retaining plug (2), a gas volume measuring device (3) and an experimental cup (4), wherein the collector (1) comprises a top cover (11), a gas collecting part (12) and a bracket (13); The top cover (11) covers the opening of the experimental cup (4), the gas collecting part (12) is installed at the bottom of the top cover (11) through the bracket (13), and the gas collecting part (12) is located inside the experimental cup (4); The retaining plug (2) is arranged in the middle gap of the top cover (11), and an axial channel (21) is arranged on the retaining plug (2); the gas volume measuring device (3) is arranged in the axial channel (21), and the top end of the gas volume measuring device (3) extends outward, and the bottom end of the gas volume measuring device (3) is communicated with the top of the gas collecting part (12) which has an extension tube (122).

2. The gas collecting device according to claim 1, characterized in that, The gas collecting part (12) comprises a gas collecting surface (121) and an extension tube (122), and the extension tube (122) is connected to the top of the gas collecting surface (121); The extension tube (122) is inserted into the bottom end of the gas volume measuring device (3), and the gas volume measuring device (3) is communicated with the space at the bottom of the gas collecting surface (121) through the extension tube (122).

3. The gas collection device of claim 1, wherein, The bracket (13) is in a cylindrical shape, the top end of the bracket (13) is connected to the inner edge of the middle gap of the top cover (11), and the bottom end of the bracket (13) is arranged at the top of the gas collecting part (12); The extension tube (122) and the bottom end of the gas volume measuring device (3) are arranged inside the cylindrical bracket (13), the side wall of the bracket (13) is provided with a through hole (131), and the inside of the bracket (13) is communicated with the inside space of the experimental cup (4) through the through hole (131).

4. The gas collection device of claim 1, wherein, The outer side of the bottom of the top cover (11) is provided with a groove (111), and the opening end surface of the experimental cup (4) is arranged in the groove (111); The top cover (11), the gas collecting part (12) and the bracket (13) are integrally formed or detachably connected, and the gas collecting surface (121) and the extension tube (122) of the gas collecting part (12) are integrally formed or detachably connected.

5. The gas collection device of claim 3, wherein The through hole (131) is arranged at one end of the side wall of the bracket (13) close to the gas collecting part (12), a plurality of through holes (131) are arranged along the circumference of the bracket (13), and the through holes (131) are lower than the liquid level in the experimental cup (4).

6. The gas collection device of claim 2, wherein, The gas collecting surface (121) is in an inverted conical structure or an inverted regular polygonal pyramid structure; When the gas collecting surface (121) is in an inverted conical structure, the top angle of the isosceles triangle of the axial section of the inverted conical structure is in the range of 30°-180°, and the ratio between the area of the bottom circle of the inverted conical structure and the area of the figure obtained by the intersection of the plane where the bottom circle of the inverted conical structure is located and the experimental cup (4) is 0.5-0.

99. The ratio between the area of the bottom surface of the inverted regular polygonal prism structure and the area of the intersection between the surface of the bottom surface of the inverted regular polygonal prism structure and the experimental cup (4) is 0.4-0.

98.

7. The gas collection device of claim 1, wherein The retaining plug (2) comprises a circular truncated cone type retaining plug.

8. The gas collection device of claim 1, wherein, The experimental cup (4) comprises a cylindrical type experimental cup, a cuboid type experimental cup, a square type experimental cup or a circular truncated cone type experimental cup.

9. The gas collection device of claim 1, wherein, The retaining plug (2) is vertically clamped in the middle gap of the collector (1), and the gas volume measuring device (3) vertically penetrates the axial channel (21) of the retaining plug (2); The top end of the gas volume measuring device (3) extends out of the axial channel (21) and vertically extends outward, and the bottom end of the gas volume measuring device (3) is vertically arranged in the liquid surface in the experimental cup (4).

10. The gas collection device of claim 2, wherein, The gas volume measuring device (3) is in a circular tube structure, the outer diameter of the gas volume measuring device (3) is less than or equal to the inner diameter of the axial channel (21), and the inner diameter of the gas volume measuring device (3) is greater than the outer diameter of the extension pipe (122).

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