Flame propagation characteristic testing device

Abstract

The invention discloses a flame propagation characteristic testing device which comprises a combustion chamber and a buffer chamber, the combustion chamber comprises a transparent enclosure wall and a first supporting part, the internal space of the transparent enclosure wall is used for forming a combustion cavity, the transparent enclosure wall is connected to the first supporting part, and the first supporting part is provided with a micro-channel; the micro-channel is communicated with the internal space of the transparent enclosure wall; the buffer chamber is provided with a nozzle facing the micro-channel, and the nozzle is used for conveying the combustion-supporting mixed gas to the micro-channel. The combustion chamber is defined by the transparent enclosure bulkhead in the combustion chamber, flames formed by the combustion phenomenon are located in the combustion chamber, a worker can conveniently observe through the transparent enclosure bulkhead, and a light path of an optical diagnosis system can conveniently penetrate through the combustion chamber; the nozzle conveys combustion-supporting mixed gas to the micro-channel, so that the flame propagation characteristic test device can be used for the quenching mechanism and influence factors of premixed flame in the micro-channel.

Description

Technical Field

[0001] The present application relates to the field of experimental equipment, and in particular to a flame propagation characteristic test device. Background Art

[0002] As an advanced combustion technology for internal combustion engines, pre-combustion chamber technology can significantly improve the thermal efficiency and combustion stability of internal combustion engines by optimizing the ignition and combustion process. The fuel in the active pre-combustion chamber is ignited by the spark plug and forms a high-temperature, free radical-rich jet through the nozzle, which then ignites the lean mixture in the main combustion chamber.

[0003] The pre-combustion chamber jet ignition method can improve the ignition energy, extend the lean combustion limit, and reduce carbon emissions. However, there are still some challenges in the practical application of pre-combustion chamber technology. For example, the premixed flame in the pre-combustion chamber is prone to quenching when entering the main combustion chamber through a tiny channel, resulting in ignition failure or incomplete combustion.

[0004] At present, although the constant volume combustion bomb, optical engine and other test benches for in-cylinder combustion visualization tests can simulate part of the combustion process of the internal combustion engine, they cannot directly observe the combustion, propagation and quenching process of the premixed flame in the precombustion chamber and the nozzle. As a result, it is difficult to study the quenching mechanism and influencing factors of the premixed flame in the tiny channel of the precombustion chamber, which limits the ability to accurately control the quenching degree of the premixed flame and the ignition energy of the precombustion chamber jet. Summary of the invention

[0005] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, the present application proposes a flame propagation characteristic test device, which is convenient for workers to observe the propagation characteristics of the premixed flame micro-channel inside the combustion chamber.

[0006] According to the flame propagation characteristics test device of the first aspect embodiment of the present application, the flame propagation characteristics test device includes a combustion chamber and a buffer chamber, the combustion chamber includes a transparent surrounding wall and a first supporting component, the internal space of the transparent surrounding wall is used to form a combustion chamber, the transparent surrounding wall is connected to the first supporting component, the first supporting component is provided with a microchannel, and the microchannel is connected to the internal space of the transparent surrounding wall; the buffer chamber is provided with a nozzle facing the microchannel, and the nozzle is used to transport the combustion-supporting mixed gas to the microchannel.

[0007] The flame propagation characteristics test device according to the embodiment of the present application has at least the following beneficial effects: a combustion chamber is defined by a transparent surrounding wall in the combustion chamber, and the flame formed by the combustion phenomenon is in the combustion chamber, which is convenient for the staff to observe through the transparent surrounding wall, and also convenient for the optical path of the optical diagnostic system to pass through the combustion chamber, that is, enter from one side, emit from the other side and be captured by the camera; the nozzle transports the combustion-supporting mixed gas to the microchannel, so that the flame propagation characteristics test device can be used for the quenching mechanism and influencing factors of the premixed flame in the tiny channel.

[0008] According to some embodiments of the present application, the transparent surrounding wall is made of quartz glass.

[0009] According to some embodiments of the present application, the combustion chamber further includes a second supporting component, the transparent surrounding wall is provided with an opening, and the first supporting component and the second supporting component clamp the transparent surrounding wall to seal the opening.

[0010] According to some embodiments of the present application, the first supporting component and the second supporting component are both provided with a sealing structure, and the transparent surrounding wall is sealed and connected to the first supporting component and the second supporting component through the sealing structure.

[0011] According to some embodiments of the present application, the sealing structure includes an installation groove and a sealing component arranged on the first supporting component and the second supporting component, the sealing component is located inside the installation groove, and the end of the transparent surrounding wall is embedded in the installation groove to resist the sealing component.

[0012] According to some embodiments of the present application, the second supporting component is provided with a combustion assembly extending into the combustion chamber, and the combustion assembly includes an ignition component and a fuel supply component, the fuel supply component is used to provide fuel into the combustion chamber, and the ignition component is used to ignite the fuel in the combustion chamber.

[0013] According to some embodiments of the present application, a pressing block is connected to the second supporting component, and the pressing block is used to press the fuel supply component onto the second supporting component so that the fuel supply component is connected to the second supporting component.

[0014] According to some embodiments of the present application, the flame propagation characteristics testing device also includes a casing assembly, which includes a bracket and an isolation component, the combustion chamber and the buffer chamber are both connected to the bracket, and the bracket and the isolation component enclose a hollow space to accommodate the combustion chamber and the buffer chamber.

[0015] According to some embodiments of the present application, a buffer cavity is provided inside the buffer chamber, and the buffer cavity is connected to the nozzle. The outer wall of the buffer chamber is provided with a fuel inlet and an oxidant inlet connected to the buffer cavity, and the fuel inlet and the oxidant inlet are used to transport fuel and oxidant to the buffer cavity.

[0016] According to some embodiments of the present application, the buffer chamber and the casing assembly form a accommodating chamber for accommodating the combustion chamber. The buffer chamber is provided with a protective gas inlet, which is connected to the accommodating chamber for conveying protective gas to the accommodating chamber.

[0017] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings are used to provide further understanding of the technical solution disclosed in the present application and constitute a part of the specification. Together with the embodiments disclosed in the present application, they are used to explain the technical solution disclosed in the present application and do not constitute a limitation on the technical solution disclosed in the present application.

[0019] Figure 1 This is a schematic diagram of the structure of the flame propagation characteristics test device of the embodiment of the present application;

[0020] Figure 2 A top view of a flame propagation characteristics test device according to an embodiment of the present application;

[0021] Figure 3 An exploded diagram of a combustion chamber in a flame propagation characteristics test device according to an embodiment of the present application;

[0022] Figure 4 It is a right view of the combustion chamber in the flame propagation characteristics test device of the embodiment of the present application;

[0023] Figure 5 A cross-sectional view of a combustion chamber in a flame propagation characteristics test device according to an embodiment of the present application;

[0024] Figure 6 It is a cross-sectional view of a combustion chamber and a buffer chamber in a flame propagation characteristics test device according to an embodiment of the present application.

[0025] Reference numerals:

[0026] Combustion chamber 100; transparent surrounding wall 101; first support member 102; combustion chamber 103; microchannel 104; second support member 105;

[0027] Ignition component 201; fuel supply component 202; pressing block 203;

[0028] Support 301; Isolation component 302; Accommodating chamber 303;

[0029] Buffer chamber 400 ; nozzle 401 ; buffer cavity 402 ; fuel inlet 403 ; oxidant inlet 404 ; shielding gas inlet 405 . DETAILED DESCRIPTION

[0030] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0031] In the description of the present application, it should be understood that descriptions involving orientation, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0032] In the description of this application, "several" means more than one, "more" means more than two, "greater than", "less than", "exceed", etc. are understood to exclude the number itself, and "above", "below", "within", etc. are understood to include the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0033] In the description of this application, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in this application based on the specific content of the technical solution.

[0034] In the description of the present application, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0035] like Figure 1 and Figure 2As shown, the embodiment of the present application provides a flame propagation characteristic test device, which includes a combustion chamber 100 and a buffer chamber 400. The combustion phenomenon is carried out in the combustion chamber 100, and the staff can observe the combustion, propagation and quenching process in the combustion chamber 100. At the same time, the combustion chamber 100 is provided with a microchannel 104, and the buffer chamber 400 sprays the combustion-supporting mixed gas along the microchannel 104 to the combustion chamber 100, which is convenient for studying the quenching mechanism and influencing factors of the premixed flame in the microchannel.

[0036] In some examples, the combustion chamber 100 includes a transparent wall 101, which is made of a transparent material, and a hollow portion of the transparent wall 101 forms a combustion chamber 103. The combustion phenomenon occurs in the combustion chamber 103, that is, the flame formed by the combustion phenomenon is in the combustion chamber 103.

[0037] Since all parts of the transparent enclosure 101 are transparent, it is convenient for the staff to observe the combustion phenomenon in the combustion chamber 103 at various angles and positions. In addition, the combustion chamber 103 is also suitable for the optical diagnosis system, which has an emission process and a capture process. Since the transparent enclosure 101 is light-transmissive in all directions, light can be emitted from one side of the transparent enclosure 101 and emitted from the other side and captured by the camera, which has strong versatility.

[0038] Furthermore, the transparent surrounding wall 101 is substantially formed into a cylindrical structure, and the shape of the cylindrical structure is set according to actual needs. Specifically, both ends of the transparent surrounding wall 101 have openings.

[0039] At the same time, if Figure 3 , Figure 4 and Figure 5 As shown, the combustion chamber 100 further includes a first support member 102, which is formed into a plate-like structure, and the transparent surrounding wall 101 is connected to the first support member 102. Specifically, the first support member 102 covers an opening at one end of the transparent surrounding wall 101, and the first support member 102 and the transparent surrounding wall 101 together define a combustion chamber 103.

[0040] In addition, the microchannel 104 is arranged through the first supporting member 102 , which is convenient for the staff to study the quenching mechanism and influencing factors of the premixed flame in the microchannel. The microchannel 104 is within the opening range of the transparent surrounding wall 101 , and the microchannel 104 is connected to the combustion chamber 103 .

[0041] In some examples, the transparent surrounding wall 101 is made of quartz glass, and the quartz glass can be set at different heights to change the volume of the combustion chamber 103. Various optical diagnostic methods, such as schlieren method, planar laser induced fluorescence method, and sample image velocimetry, can be applied to the combustion chamber 103 for high-frequency diagnosis to study the flame propagation process, particle motion, and distribution of important free radicals.

[0042] In some examples, such as Figure 3 , Figure 4 and Figure 5 As shown, the combustion chamber 100 further includes a second support member 105, which is also formed into a plate-like structure. The second support member 105 covers the other end opening of the transparent surrounding wall 101, that is, the first support member 102 and the second support member 105 jointly clamp the transparent surrounding wall 101, so that the combustion chamber 103 is formed into a relatively closed space.

[0043] Specifically, the first support member 102 is located at the bottom of the transparent surrounding wall 101, and the second support member 105 is located at the top of the transparent surrounding wall 101. The first support member 102 and the second support member 105 are connected to each other by a plurality of fasteners to maintain the clamping effect of the two on the transparent surrounding wall 101. Among them, the horizontal dimensions of the first support member 102 and the second support member 105 are greater than the horizontal dimensions of the transparent surrounding wall 101, and the fasteners are distributed on the outside of the transparent surrounding wall 101.

[0044] In some examples, in order to ensure the sealing between the transparent surrounding wall 101 and the first supporting member 102, and the sealing between the transparent surrounding wall 101 and the second supporting member 105, the first supporting member 102 and the second supporting member 105 are both provided with a sealing structure. One open end of the transparent surrounding wall 101 is connected to the first supporting member 102 through the sealing structure, and the other open end is connected to the second supporting member 105 through the sealing structure, thereby ensuring the sealing between the transparent surrounding wall 101, the first supporting member 102 and the second supporting member 105.

[0045] In some examples, the sealing structure includes a mounting groove and a sealing component provided on the first supporting member 102 and the second supporting member 105. Specifically, the shape of the mounting groove matches the end opening shape of the transparent surrounding wall 101, and the sealing component is a sealing ring.

[0046] The sealing ring is installed inside the installation groove, and the end of the transparent surrounding wall 101 is embedded in the installation groove to ensure the installation accuracy of the transparent surrounding wall 101. The transparent surrounding wall 101 contacts the sealing component, and the sealing component plays a sealing role between the transparent surrounding wall 101 and the first supporting component 102.

[0047] In some examples, the second support component 105 is provided with a combustion assembly extending into the combustion chamber 103, and the combustion assembly passes through the second support component 105. The combustion assembly includes an ignition component 201 and a fuel supply component 202. Specifically, the ignition component 201 is a spark plug, and the fuel supply component 202 is an injector. The ignition component 201 is threadedly connected to the second support component 105 and obliquely passes through the second support component 105.

[0048] The fuel supply component 202 is used to provide fuel into the combustion chamber 103 , and the ignition component 201 is used to ignite the fuel in the combustion chamber 103 .

[0049] Furthermore, the ignition component 201 is provided with a spark plug pressure sensor to facilitate accurate control of the ignition time. At the same time, the pressure sensor can also collect pressure information in the combustion chamber 103. The fuel supply component 202 can change the injection pressure and pulse width of the fuel, so that a certain mass of fuel is injected into the combustion chamber 103 at a preset injection pressure and pulse width, thereby forming a premixed gas of the required equivalent concentration in the combustion chamber 103.

[0050] In some examples, the second support component 105 is connected to a pressing block 203, the pressing block 203 is connected to the fuel supply component 202, and the fuel supply component 202 is located between the second support component 105 and the pressing block 203. The pressing block 203 and the second support component 105 form a clamping effect on the fuel supply component 202, and the pressing block 203 transmits the pre-tightening force to the fuel supply component 202, so that the fuel supply component 202 is continuously pressed on the second support component 105.

[0051] It is understandable that there is a certain interval between the pressing block 203 and the second supporting component 105 , and they are connected to each other by a plurality of fasteners. Specifically, the fasteners are distributed on the outside of the fuel supply component 202 .

[0052] In addition, in order to ensure the connection stability and sealing between the fuel supply component 202 and the pressure block 203 and the second support component 105, the fuel supply component 202 and the pressure block 203 are sealed by a sealing ring, and the fuel supply component 202 and the second support component 105 are pressed and sealed by a copper gasket.

[0053] In some examples, such as Figure 1 As shown, the flame propagation characteristic test device also includes a housing assembly, and the housing assembly includes a bracket 301 and an isolation component 302. Among them, a plurality of brackets 301 are provided, and isolation components 302 are connected between adjacent brackets 301, so that each bracket 301 and each isolation component 302 together enclose a hollow space. Specifically, the isolation component 302 is made of glass material, so that the space enclosed by the bracket 301 and the isolation component 302 is relatively closed, and it is convenient for the staff to observe the combustion phenomenon through the isolation component 302.

[0054] Furthermore, the combustion chamber 100 and the buffer chamber 400 are connected to the bracket 301 and are located in the space enclosed by the bracket 301 and the isolation component 302. At the same time, each bracket 301 also forms a channel for adjusting the height of the combustion chamber 100. The second support component 105 in the combustion chamber 100 is slidably connected to the bracket 301. When the second support component 105 is adjusted to a preset height, it is fastened to the bracket 301 by a fastener, thereby locking the height of the combustion chamber 100.

[0055] In some examples, such as Figure 6 As shown, the buffer chamber 400 is formed as a hollow structure, and the buffer chamber 400 is provided with a nozzle 401 , which is connected to the hollow portion of the buffer chamber 400 and faces the microchannel 104 .

[0056] The buffer chamber 400 is used to contain the combustion-supporting mixed gas, and the combustion-supporting buffer gas is sprayed to the position of the microchannel 104 under the action of the nozzle 401. Since there is a flame inside the combustion chamber 103, and the flame will spray out of the combustion chamber 103 along the microchannel 104, the sprayed flame interacts with the combustion-supporting buffer gas outside the microchannel 104. The combustion-supporting mixed gas has various forms, which can be an oxidant or a mixture of an oxidant and a fuel, so that it is convenient to study the quenching of the flame sprayed from the microchannel under different incoming gases.

[0057] In some examples, the hollow portion inside the buffer chamber 400 is the buffer cavity 402, the buffer cavity 402 is connected to the nozzle 401, and the outer wall of the buffer chamber 400 is provided with a fuel inlet 403 and an oxidant inlet 404 connected to the buffer cavity 402. The fuel inlet 403 is used to transport fuel into the buffer cavity 402, and the oxidant inlet 404 is used to transport oxidant into the buffer cavity 402, so as to form a combustion-supporting mixed gas inside the buffer cavity 402.

[0058] The buffer chamber 400 is provided with a pressure sensor, and the gas drawn from the gas cylinder and configured in the buffer chamber 400 according to Dalton's law of partial pressure may be a mixture of an oxidant and a fuel gas. It is understandable that the specific composition of the mixed gas needs to be calculated first, and then it is filled into the buffer chamber 400 and ejected from the nozzle 401, thereby forming an incoming flow gas in the combustion chamber 103. By changing the composition of the gas, the quenching phenomenon of the jet flame and the flame propagation phenomenon of the jet flame igniting the incoming flow can be explored.

[0059] Specifically, a heating wire is arranged around the buffer chamber 400, and a temperature sensor is arranged inside the buffer chamber 400. By controlling the temperature of the mixed gas in the buffer chamber 400 through the heating wire, the influence of the incoming flow temperature on the flame propagation can be explored.

[0060] In some examples, the combustion chamber 100 is located at the top of the buffer chamber 400 , and the buffer chamber 400 and the casing assembly form a receiving chamber 303 for accommodating the combustion chamber 100 . It can be understood that the receiving chamber 303 is located at the top of the buffer chamber 400 .

[0061] Furthermore, the buffer chamber 400 is provided with a protective gas inlet 405, which is connected to the accommodating chamber 303, and the protective gas can fill the accommodating chamber 303 along the protective gas inlet 405, thereby providing a certain degree of protection against unexpected situations that may occur during the combustion process. Specifically, the protective gas is nitrogen.

[0062] When the flame propagation characteristic test device is used for testing, it is necessary to control a single variable, which includes the type of fuel in the quartz glass combustion chamber 100, the diameter and length of the microchannel 104, the equivalence ratio of the mixed gas configured in the combustion chamber 103, the volume of the combustion chamber 103, the distance between the microchannel 104 and the incoming gas, the composition of the incoming gas, the speed of the incoming gas, the temperature of the incoming gas, etc.

[0063] In summary, in the actual implementation process, the flame propagation characteristics test device is conducive to enhancing optical observation capabilities, fine variable control, and improving functions and flexibility. In terms of enhancing optical observation capabilities, this application proposes a visual combustion device, which uses a quartz glass window with high transparency and high heat resistance to achieve all-round direct observation of the premixed flame combustion process. Combined with optical diagnostic technology, detailed flame structure, propagation dynamics and chemical reaction information can be obtained. In terms of fine variable control, this application forms a set of precision control systems. Unlike traditional constant volume combustion systems, it can adjust key parameters such as the incoming flow equivalence ratio, flow rate, channel length, diameter and premixed equivalence ratio alone or in combination, and systematically explore the specific effects of the above factors on flame quenching, propagation speed and combustion efficiency, providing detailed data support for optimizing jet ignition technology. In terms of improving functions and flexibility, this application adopts a modular design, and the components are tightly connected and easy to disassemble and replace. Parameters such as nozzle position, height, and nozzle diameter can be quickly adjusted according to specific research objectives, without the need for complex reconstruction processes, improving experimental efficiency and flexibility, and being suitable for combustion research under a variety of fuels and working conditions.

[0064] In some selectable embodiments, the function / operation mentioned in the block diagram may not occur in the order mentioned in the operation diagram. For example, depending on the function / operation involved, the two boxes shown in succession can actually be executed substantially simultaneously or the boxes can sometimes be executed in reverse order. In addition, the embodiment presented and described in the flow chart of the application is provided by way of example, for the purpose of providing a more comprehensive understanding of technology. The disclosed method is not limited to the operation and logic flow presented herein. Selectable embodiments are expected, wherein the order of various operations is changed and the sub-operation of a part described as a larger operation is performed independently.

[0065] The embodiments of the present application are described in detail above in conjunction with the accompanying drawings, but the present application is not limited to the above embodiments. Various changes can be made within the knowledge of ordinary technicians in the relevant technical field without departing from the purpose of the present application. In addition, the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

Claims

1. A flame propagation characteristics test device, characterized in that: include: A combustion chamber, the combustion chamber comprising a transparent surrounding wall and a first supporting member, the internal space of the transparent surrounding wall is used to form a combustion chamber, the transparent surrounding wall is connected to the first supporting member, the first supporting member is provided with a microchannel, and the microchannel is connected to the internal space of the transparent surrounding wall; A buffer chamber is provided with a nozzle facing the microchannel, and the nozzle is used to transport the combustion-supporting mixed gas to the microchannel.

2. The flame propagation characteristics test device according to claim 1, characterized in that: The transparent surrounding wall is made of quartz glass.

3. The flame propagation characteristics test device according to claim 1 or 2, characterized in that: The combustion chamber further includes a second supporting component, the transparent surrounding wall is provided with an opening, and the first supporting component and the second supporting component clamp the transparent surrounding wall to block the opening.

4. The flame propagation characteristics test device according to claim 3, characterized in that: The first supporting component and the second supporting component are both provided with a sealing structure, and the transparent surrounding wall is sealed and connected to the first supporting component and the second supporting component through the sealing structure.

5. The flame propagation characteristics test device according to claim 4, characterized in that: The sealing structure includes a mounting groove and a sealing component which are arranged on the first supporting component and the second supporting component. The sealing component is located inside the mounting groove, and the end of the transparent surrounding wall is embedded in the mounting groove to abut against the sealing component.

6. The flame propagation characteristics test device according to claim 3, characterized in that: The second supporting component is provided with a combustion assembly extending into the combustion chamber, and the combustion assembly includes an ignition component and a fuel supply component. The fuel supply component is used to provide fuel into the combustion chamber, and the ignition component is used to ignite the fuel in the combustion chamber.

7. The flame propagation characteristics test device according to claim 6, characterized in that: The second supporting component is connected to a pressing block, and the pressing block is used to press the fuel supply component onto the second supporting component so that the fuel supply component is connected to the second supporting component.

8. The flame propagation characteristics test device according to claim 1, characterized in that: The flame propagation characteristic test device also includes a casing assembly, which includes a bracket and an isolation component. The combustion chamber and the buffer chamber are both connected to the bracket, and the bracket and the isolation component enclose a hollow space to accommodate the combustion chamber and the buffer chamber.

9. The flame propagation characteristics test device according to claim 1, characterized in that: A buffer cavity is arranged inside the buffer chamber, and the buffer cavity is connected to the nozzle. A fuel inlet and an oxidant inlet connected to the buffer cavity are arranged on the outer wall of the buffer chamber, and the fuel inlet and the oxidant inlet are used to transport fuel and oxidant to the buffer cavity.

10. The flame propagation characteristics test device according to claim 8, characterized in that: The buffer chamber and the casing assembly form a containing chamber for accommodating the combustion chamber. The buffer chamber is provided with a protective gas inlet, which is connected to the containing chamber and is used to transport protective gas to the containing chamber.

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