Microwave steam plasma generating source and microwave steam plasma generating method using same

Abstract

A microwave steam plasma generating source is disclosed. The microwave steam plasma generating source includes: a preheating module having a first plasma generating part provided therein and including a first injection port which allows plasma discharge gas to be injected into the first plasma generating part; and a steam supply module which is coaxially disposed with the preheating module, has a second plasma generating part provided therein to communicate with the first plasma generating part, and includes a second injection port which allows a liquid to be injected into the second plasma generating part, wherein the preheating module or the steam supply module is connected to a microwave transmission part for transmitting electromagnetic waves; and after the plasma discharge gas is injected through the first injection port and thus plasma is generated by the electromagnetic waves, the liquid injected through the second injection port is injected thereinto and thus supplied as steam.

Description

Microwave steam plasma generation source and microwave steam plasma generation method using the same

[0001] The present invention relates to a microwave steam plasma generation source, and more particularly, to a microwave steam plasma capable of generating more stable microwave steam plasma.

[0002] Electromagnetic plasma torches are widely used in hydrocarbon gasification, the decomposition and reforming of hazardous gases, and material synthesis. In particular, electromagnetic steam plasma torches, as electrodeless plasma sources, utilize OH radicals to generate energy and oxidation processes, such as hydrogen and carbon monoxide conversion.

[0003] Conventional electromagnetic steam plasma torches utilize a single swirl gas supply structure that injects discharge gas into the discharge tube. The steam required for steam plasma generation is heated by electricity or the heat generated by burning hydrocarbon fuel. This can generate secondary byproducts, potentially causing environmental problems due to hazardous gases.

[0004] Additionally, the single swirl method has the problem of plasma instability because the probability of condensation occurring increases when mixing steam and cold discharge gas.

[0005] According to one embodiment of the present invention, a microwave steam plasma generation source comprises: a preheating module having a first plasma generation unit provided therein and a first injection port for injecting plasma discharge gas into the first plasma generation unit; and a steam supply module coaxially disposed with the preheating module, having a second plasma generation unit provided therein in communication with the first plasma generation unit, and including a second injection port for injecting liquid into the second plasma generation unit, wherein the preheating module or the steam supply module is connected to a microwave transmission unit that transmits electromagnetic waves, and the liquid injected through the second injection port is injected and supplied as steam after plasma is generated by the electromagnetic waves by injecting the plasma discharge gas through the first injection port.

[0006] In one embodiment, the preheating module and the steam supply module are cylindrical in shape, and the first injection port and the second injection port are connected in a tangential direction of the cylinder so that the plasma discharge gas and the liquid can be injected in a swirl manner.

[0007] In one embodiment, the preheating module and the steam supply module are provided with a double-tube structure including a cylindrical inner tube and a cylindrical outer tube in fluid communication with the cylindrical inner tube, the outer and inner surfaces of the cylindrical inner tube being spaced apart from each other and arranged coaxially, and the preheating module and the steam supply module each have cylindrical inner tubes in fluid communication with each other and each cylindrical outer tube is arranged to be shielded from each other, and the first injection port and the second injection port can be tangentially connected to the cylindrical outer tubes of the preheating module and the steam supply module, respectively.

[0008] In one embodiment, the preheating module and the steam supply module each include a fluid inlet opening penetrating tangentially into the cylindrical inner tube, and the cylindrical inner tube and the cylindrical outer tube can be in fluid communication through the fluid inlet opening.

[0009] In one embodiment, the steam supply module further includes a steam swirl guide that swirls the steam in a first direction away from the second injection port along the axial direction of the double pipe and then swirls the steam in a second direction opposite to the first direction, and the fluid inlet opening of the steam supply module may be arranged at an end direction of the second direction.

[0010] In one embodiment, the steam swirl guide comprises: a first guide portion having a cylindrical shape having a thickness less than or equal to the gap between the cylindrical inner tube and the cylindrical outer tube of the steam supply module, and having spiral grooves formed on the inner and outer surfaces thereof along the axial direction; and a second guide portion extending cylindrically from one side of the first guide portion and having a thickness less than the thickness of the first guide portion, wherein the total length of the steam swirl guide is shorter than the lengths of the cylindrical inner tube and the cylindrical outer tube of the steam supply module, and the second guide portion is spaced apart from the inner surface of the cylindrical inner tube and the outer surface of the cylindrical outer tube of the steam supply module and faces the second injection port and the fluid inlet opening, and the first guide portion may be arranged so as to be in close contact with the inner surface of the cylindrical inner tube and the outer surface of the cylindrical outer tube of the steam supply module, but an end of the second guide portion opposite to the inner surface of the cylindrical inner tube and the outer surface of the cylindrical outer tube of the steam supply module is positioned higher than an end of each of the cylindrical inner tube and the cylindrical outer tube of the steam supply module.

[0011] Accordingly, the problem to be solved by the present invention is to provide a microwave steam plasma generator capable of converting water into steam by preheating a plasma generator, and maintaining the steam plasma by supplying steam after forming the plasma by injecting a gaseous discharge gas through two independent discharge gas supply structures, thereby enabling more stable steam plasma generation, and generating steam without consuming additional energy.

[0012] According to the microwave steam plasma generator according to the present invention, by separately injecting steam supply and gaseous discharge gas through two independent injection ports, there is an advantage in that stable microwave steam plasma can be formed by steam without the problem of plasma becoming unstable due to condensation caused by cold gas when gaseous discharge gas and steam are mixed and injected.

[0013] In addition, it is possible to convert water into steam by preheating the plasma source without a separate steam supply device, and since the plasma is formed by injecting gaseous discharge gas through two independent discharge gas supply structures and then steam is supplied to maintain the plasma by steam, more stable steam plasma generation is possible, and there is an advantage in that steam can be generated without consuming additional energy.

[0014] In addition, the area where steam is injected, i.e., the steam supply module, is equipped with a double-pipe structure, and the steam converted from a water and liquid state is injected while moving in a swirl manner through the double spiral lines (first spiral groove and second spiral groove) of the steam swirl guide, so that not only is cooling of the plasma generation source possible, but also a heat source and time sufficient for water to be converted into steam are provided, so that a stable supply of steam can be possible.

[0015] In addition, since water is supplied in a preheated state after plasma formation, rapid steam production can be achieved through instantaneous heating of water using plasma waste heat.

[0016] FIG. 1 is a cross-sectional view illustrating a microwave steam plasma generation source according to one embodiment of the present invention.

[0017] Fig. 2 is a cross-sectional view showing the microwave steam plasma generator illustrated in Fig. 1 connected to a waveguide.

[0018] Hereinafter, a microwave steam plasma generator according to an embodiment of the present invention will be described in detail with reference to the attached drawings. The present invention can be modified in various ways and can take various forms, and specific embodiments are illustrated in the drawings and described in detail in the text. However, this is not intended to limit the present invention to a specific disclosed form, but it should be understood that the invention includes all modifications, equivalents, and substitutes included in the spirit and technical scope of the present invention. In describing each drawing, similar reference numerals are used to indicate similar components. In the attached drawings, the dimensions of structures are shown larger than actual size to ensure clarity of the present invention.

[0019] While terms like "first" and "second" may be used to describe various components, these components should not be limited by these terms. These terms are used solely to distinguish one component from another. For example, without departing from the scope of the present invention, a first component could be referred to as a "second component," and similarly, a second component could also be referred to as a "first component."

[0020] The terminology used in this application is only used to describe specific embodiments and is not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this application, it should be understood that the terms "comprise" or "have" indicate the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but do not preclude the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0021] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and will not be interpreted in an idealized or overly formal sense unless explicitly defined herein.

[0022] FIG. 1 is a cross-sectional view illustrating a microwave steam plasma generation source according to one embodiment of the present invention, and FIG. 2 is a cross-sectional view showing the microwave steam plasma generation source illustrated in FIG. 1 connected to a waveguide.

[0023] Referring to FIG. 1, a microwave steam plasma generation source according to one embodiment of the present invention may include a preheating module (100) and a steam supply module (200).

[0024] The preheating module (100) may have a first plasma generating unit (110a) provided therein and may include a first injection port (130) for injecting plasma discharge gas into the first plasma generating unit (110a).

[0025] In one embodiment, the preheating module (100) may be provided with a double-tube structure including a first cylindrical inner tube (110) and a first cylindrical outer tube (120). At this time, the first cylindrical inner tube (110) and the first cylindrical outer tube (120) are arranged coaxially, and the outer surface of the first cylindrical inner tube (110) and the inner surface of the first cylindrical outer tube (120) are spaced apart from each other to form a space that receives plasma discharge gas injected from the first injection port (130). In this case, the first injection port (130) is connected in a tangential direction of the circumference of the first cylindrical outer tube (120), so that the plasma discharge gas can be injected in a swirl manner.

[0026] In addition, the preheating module (100) can form a first plasma generating unit (110a) inside the first cylindrical inner tube (110), and a first fluid inlet opening (140) is formed in the first cylindrical inner tube (110) so that the first cylindrical inner tube (110) and the first cylindrical outer tube (120) can be in fluid communication. At this time, the first fluid inlet opening (140) is positioned facing the spaced apart space between the first cylindrical inner tube (110) and the first cylindrical outer tube (120), and the first fluid inlet opening (140) penetrates the first cylindrical inner tube (110) in a tangential direction so that the plasma discharge gas flowing into the first fluid inlet opening (140) can flow in as a swirl.

[0027] The steam supply module (200) is arranged coaxially with the preheating module (100), and has a second plasma generating unit (210a) provided therein that communicates with the first plasma generating unit (110a), and may include a second injection port (230) for injecting liquid into the second plasma generating unit (210a).

[0028] In one embodiment, the steam supply module (200) may be provided with a double-tube structure including a second cylindrical inner tube (210) and a second cylindrical outer tube (220). At this time, the second cylindrical inner tube (210) and the second cylindrical outer tube (220) are arranged coaxially, and the outer surface of the second cylindrical inner tube (210) and the inner surface of the first cylindrical outer tube (120) are spaced apart from each other so that a space is formed in which liquid injected from the second injection port (230) and steam vaporized from the liquid are received. In this case, the second injection port (230) is connected in a tangential direction of the circumference of the second cylindrical outer tube (220), so that the liquid can be injected in a swirl manner.

[0029] In addition, the steam supply module (200) can form a second plasma generating unit (210a) inside the second cylindrical inner tube (210), and a second fluid inlet opening (240) is formed in the second cylindrical inner tube (210) so that the second cylindrical inner tube (210) and the second cylindrical outer tube (220) can be in fluid communication. At this time, the second fluid inlet opening (240) is positioned facing the spaced apart space between the second cylindrical inner tube (210) and the second cylindrical outer tube (220), and the second fluid inlet opening (240) penetrates the second cylindrical inner tube (210) in a tangential direction so that steam flowing into the second fluid inlet opening (240) can flow in as a swirl.

[0030] Meanwhile, the steam supply module (200) may further include a steam swirl guide (250).

[0031] The steam swirl guide (250) can move steam in a first direction away from the second injection port (230) along the axial direction of the double-pipe structure of the steam supply module (200), and then move it in a second direction opposite to the first direction.

[0032] In one embodiment, the steam swirl guide (250) may include a first guide portion (251) and a second guide portion (252).

[0033] The first guide portion (251) may be formed in a cylindrical shape having a thickness less than or equal to the gap between the outer surface of the second cylindrical inner tube (210) of the steam supply module (200) and the inner surface of the second cylindrical outer tube (220). For example, the first guide portion (251) may have a thickness that is in close contact with the outer surface of the second cylindrical inner tube (210) and the inner surface of the second cylindrical outer tube (220). In addition, the first guide portion (251) may have a first spiral groove (251a) formed along the axial direction on the inner surface thereof, and a second spiral groove (251b) formed along the axial direction on the outer surface thereof. At this time, the first spiral groove (251a) may be formed in a spiral shape having a slope toward the end in the first direction, and the second spiral groove (251b) may be formed in a spiral shape having a slope toward the end in the second direction.

[0034] The second guide portion (252) may be cylindrically extended from one side of the first guide portion (251) with a thickness that is less than that of the first guide portion (251). That is, it may be formed with a thickness that is spaced apart from the inner surface of the second cylindrical inner tube (210) of the steam supply module (200) and the outer surface of the second cylindrical inner tube (210), and may be positioned to face the second injection port (230) and the second fluid inlet opening (240).

[0035] The overall length of the steam swirl guide (250) may be provided to be shorter than the lengths of the second cylindrical inner tube (210) and the second cylindrical outer tube (220) of the steam supply module (200). Accordingly, the steam swirl guide (250) may be arranged such that the end of the first guide portion (251) opposite the second guide portion (252) is positioned higher than the ends of each of the second cylindrical inner tube (210) and the second cylindrical outer tube (220) of the steam supply module (200). In this case, a space may be formed below the end of the first guide portion (251) through which steam can flow into the first spiral groove (251a) after passing through the second spiral groove (251b).

[0036] These preheating modules (100) and steam supply modules (200) can be connected to each other through flanges (121, 221).

[0037] Meanwhile, the preheating module (100) or steam supply module (200) can be connected to a microwave transmission unit (300) that transmits electromagnetic waves as shown in FIG. 2.

[0038] In one embodiment, the microwave transmission unit (300) may be a right-angled waveguide and may be electromagnetically communicably connected to the preheating module (100) or the steam supply module (200). For example, the microwave transmission unit (300) may be electromagnetically communicably connected to the steam supply module (200). At this time, the second cylindrical inner tube (210) of the steam supply module (200) is formed of a dielectric material and is connected to penetrate one surface of the right-angled waveguide of the microwave transmission unit (300) so that electromagnetic waves may be input into the interior of the second cylindrical inner tube (210).

[0039] In this case, the plasma discharge gas injected through the first injection port (130) of the preheating module (100) can be excited by electromagnetic waves to form microwave plasma, and the microwave plasma can spread in the inner direction of the second cylindrical inner tube (210) of the steam supply module (200).

[0040] Additionally, a tubular plasma reactor (400) may be connected to the other side of the rectangular waveguide of the microwave transmission unit (300). At this time, the tubular plasma reactor (400) is fluidly connected to the second cylindrical inner tube (210) of the steam supply module (200) penetrating the rectangular waveguide of the microwave transmission unit (300), and the plasma may extend into the interior of the tubular plasma reactor (400).

[0041] Hereinafter, a process of generating microwave steam plasma through the injection and circulation of discharge gas and steam in a microwave steam plasma generation source according to one embodiment of the present invention will be described.

[0042] A microwave steam plasma generation method may include a step of injecting plasma discharge gas; a step of generating electromagnetic wave plasma by supplying power in an atmosphere to which electromagnetic waves are applied; a step of preheating a steam supply module using the generated electromagnetic wave plasma as a heat source; a step of supplying liquid into the steam supply module; and a step of gradually reducing the injection amount of the plasma discharge gas while blocking the injection.

[0043] Step of injecting plasma discharge gas

[0044] The discharge gas is injected between the first cylindrical outer tube (120) and the first cylindrical inner tube (110) through the first injection port (230) of the preheating module (100), and while forming a swirl, it descends along the longitudinal direction of the first cylindrical outer tube (120) and the first cylindrical inner tube (110), and then is injected into the first cylindrical inner tube (110) through the first fluid inlet opening (140) that penetrates the first cylindrical inner tube (110) in a tangential direction, while forming a swirl.

[0045] A step of generating electromagnetic plasma by supplying power in an electromagnetically energized atmosphere.

[0046] The discharge gas injected into the first cylindrical inner tube (110) is transmitted through the right-angle waveguide of the microwave transmission unit (300) and, when power is supplied in an atmosphere in which electromagnetic waves are input into the interior of the first cylindrical inner tube (110), it is excited by the electromagnetic waves and can form microwave plasma in the first plasma generation unit (110a) inside the first cylindrical inner tube (110). The microwave plasma can extend toward the interior of the tubular plasma reactor (400).

[0047] A step of preheating the steam supply module using the generated electromagnetic plasma as a heat source.

[0048] When microwave plasma is formed, the preheating module (100) and the steam supply module (200) can be preheated by the heat of the microwave plasma and maintained at a high temperature.

[0049] Step of supplying liquid into the steam supply module

[0050] Steam can be injected into a second plasma generator (210a) coaxially arranged with the first plasma generator (110a) through a steam supply module (200).

[0051] That is, liquid can be injected between the second cylindrical outer tube (220) and the second cylindrical inner tube (210) through the second injection port (230) connected in the tangential direction of the circumference of the second cylindrical outer tube (220) of the steam supply module (200).

[0052] The injected liquid is injected between the outer surface of the second guide portion (252) of the steam swirl guide (250) and the inner surface of the second cylindrical outer tube (220), and as it moves along the steam swirl guide (250), the steam supply module (200) is preheated and maintained at a high temperature, thereby generating steam, and the steam is guided through the steam swirl guide (250) and injected into the second plasma generating portion (210a) inside the second cylindrical inner tube (210).

[0053] Specifically, water spirals along the second spiral groove (251b) formed along the axial direction on the outer surface of the first guide portion (251) of the steam swirl guide (250) from between the second guide portion (252) of the steam swirl guide (250) and the second cylindrical outer tube (220) and descends toward the lower end of the second cylindrical outer tube (220) along the first direction away from the second injection port (230) to reach the space below the end of the first guide portion (251). In this process, the water can be converted into steam.

[0054] Next, the steam spirally rotates along the first spiral groove (251a) formed along the axial direction on the inner surface of the first guide portion (251) and rises toward the top of the second cylindrical inner tube (210) in the second direction in the opposite direction of the first direction, reaching the space between the second guide portion (252) of the steam swirl guide (250) and the second cylindrical inner tube (210), and then the steam is injected into the second plasma generating portion (210a) inside the second cylindrical inner tube (210) through the second fluid inlet opening (240) of the second cylindrical inner tube (210).

[0055] Steam injected in this manner can be utilized as a discharge gas in place of the discharge gas injected through the first injection port (130) of the preheating module (100). That is, after the injection of the discharge gas through the first injection port (130) is blocked, steam can be utilized as the discharge gas.

[0056] Step of gradually reducing the amount of plasma discharge gas injected and blocking the injection

[0057] In order for steam to be utilized as a discharge gas, after steam is injected into the second plasma generating part (210a) of the second cylindrical inner tube (210), the amount of discharge gas injected through the first injection port (130) is gradually reduced to check whether microwave plasma is stably maintained, and when it is confirmed that microwave plasma is stably maintained, the injection of discharge gas injected through the first injection port (130) is blocked so that only steam is utilized as a discharge gas.

[0058] Here, the process of checking whether the microwave plasma is maintained stably can be performed by visually checking or by detecting the temperature of the microwave plasma using a means for detecting the microwave plasma, such as a temperature sensor, to check whether the microwave plasma is maintained stably.

[0059] According to one embodiment of the present invention, a microwave steam plasma generator injects a gaseous discharge gas before injecting steam to form plasma, preheats the plasma generator, then injects water in the preheated state so that the water is converted into steam and injected, and after the steam is injected, the gaseous discharge gas is blocked while confirming the stabilization state of the plasma, thereby generating and maintaining microwave steam plasma that utilizes only steam as the discharge gas.

[0060] That is, the microwave steam plasma generator according to one embodiment of the present invention has the advantage of being able to form a stable microwave steam plasma by steam without the problem of plasma becoming unstable due to condensation caused by cold gas when the gaseous discharge gas and steam are mixed and injected by separately supplying steam and gaseous discharge gas through two independent injection ports (130, 230).

[0061] In addition, it is possible to convert water into steam by preheating the plasma source without a separate steam supply device, and since the plasma is formed by injecting gaseous discharge gas through two independent discharge gas supply structures and then steam is supplied to maintain the plasma by steam, more stable steam plasma generation is possible, and there is an advantage in that steam can be generated without consuming additional energy.

[0062] In addition, the area where steam is injected, i.e., the steam supply module (200), is provided with a double-pipe structure, and the steam converted from a water and liquid state is injected while moving in a swirl manner through the double spiral lines (first spiral groove (251a) and second spiral groove (251b)) of the steam swirl guide (250), so that not only is cooling of the plasma generation source possible, but also a heat source and time sufficient for water to be converted into steam are provided, so that a stable supply of steam can be possible.

[0063] In addition, since water is supplied in a preheated state after plasma formation, rapid steam production can be achieved through instantaneous heating of water using plasma waste heat.

[0064] The description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments without departing from the scope of the present invention. Therefore, the present invention is not intended to be limited to the embodiments disclosed herein, but is to be construed in the broadest scope consistent with the principles and novel features disclosed herein.

Claims

1. A preheating module having a first plasma generating unit provided therein and including a first injection port for injecting plasma discharge gas into the first plasma generating unit; and A steam supply module is provided, which is arranged coaxially with the above preheating module and has a second plasma generating unit that communicates with the first plasma generating unit inside, and includes a second injection port for injecting liquid into the second plasma generating unit. The above preheating module or the above steam supply module is connected to a microwave transmission unit that transmits electromagnetic waves, The liquid injected through the second injection port is characterized in that it is injected and supplied as steam after plasma is generated by the electromagnetic waves by injecting the plasma discharge gas through the first injection port. Microwave steam plasma generator.

2. In paragraph 1, The above preheating module and the above steam supply module are cylindrical in shape, The first injection port and the second injection port are connected in the tangential direction of the cylinder to inject the plasma discharge gas and the liquid in a swirl manner. Microwave steam plasma generator.

3. In paragraph 1, The above preheating module and the steam supply module are provided with a double-tube structure including a cylindrical inner tube and a cylindrical outer tube in which the outer and inner surfaces of the cylindrical inner tube are spaced apart and arranged coaxially and in fluid communication with the cylindrical inner tube. The above preheating module and the above steam supply module are arranged so that each cylindrical inner tube can communicate with each other and each cylindrical outer tube is shielded from each other. The first injection port and the second injection port are tangentially connected to the cylindrical outer tubes of the preheating module and the steam supply module, respectively. Microwave steam plasma generator.

4. In paragraph 3, The above preheating module and the above steam supply module each include a fluid inlet opening penetrating tangentially into each cylindrical inner tube, The above cylindrical inner tube and the above cylindrical outer tube are in fluid communication through the fluid inlet opening. Microwave steam plasma generator.

5. In paragraph 4, The steam supply module further includes a steam swirl guide that swirls the steam in a first direction away from the second injection port along the axial direction of the double pipe and then swirls it in a second direction opposite to the first direction. The fluid inlet opening of the above steam supply module is arranged at the end of the second direction. Microwave steam plasma generator.

6. In paragraph 5, The above steam swirl guide, A first guide part having a cylindrical shape having a thickness less than the gap between the cylindrical inner tube and the cylindrical outer tube of the steam supply module, and having a spiral groove formed along the axial direction on the inner and outer surfaces; and A second guide portion extending cylindrically from one side of the first guide portion and having a thickness less than that of the first guide portion, The total length of the above steam swirl guide is shorter than the length of the cylindrical inner tube and cylindrical outer tube of the above steam supply module, The second guide portion is spaced apart from the inner surface of the cylindrical inner tube and the outer surface of the cylindrical outer tube of the steam supply module and faces the second injection port and the fluid inlet opening, and the first guide portion is in close contact with the inner surface of the cylindrical inner tube and the outer surface of the cylindrical outer tube of the steam supply module, but the end opposite to the second guide portion is positioned higher than the ends of each of the cylindrical inner tube and the cylindrical outer tube of the steam supply module. Microwave steam plasma generator.

7. In paragraph 1, The above preheating module and the above steam supply module are flange-connected, Microwave steam plasma generator.

8. A microwave steam plasma generation method using the microwave steam plasma generation source of paragraph 1, Step of injecting plasma discharge gas; A step of generating microwave plasma by supplying power in an electromagnetically energized atmosphere; A step of preheating a steam supply module using the generated microwave plasma as a heat source; A step of supplying liquid into the steam supply module; and Including a step of gradually reducing the injection amount of the plasma discharge gas while blocking the injection, Microwave steam plasma generation method.

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