Plasma irradiation device and method for producing plasma-treated liquid

Abstract

An atmospheric pressure plasma irradiation apparatus 10 comprises: a cover housing 22 that demarcates a predetermined space; a plasma generation device 20 that ejects plasma to the inside of the cover housing 22; a purge gas supply mechanism 32 that supplies gas to the inside of the cover housing 22; a stage 26 that is provided in the inside of the cover housing 22 and that holds a treatment target liquid; a duct port 160 which is provided in a lower part of the cover housing 22 and through which gas is discharged from the inside of the cover housing 22; and a liquid reservoir part 151 that is provided at the lower side of the duct port 160 and that stores a portion of the treatment target liquid having leaked from the stage 26.

Description

[Technical Field]

[0001] The present disclosure relates to a technique for irradiating a liquid to be treated with plasma. [Background technology]

[0002] Patent Document 1 describes an apparatus for plasma-treating a liquid (culture solution) held inside a cover housing. Specifically, an inert gas is supplied into the cover housing, and when the oxygen concentration inside the cover housing falls below a predetermined value, a plasma generator ejects plasma into the cover housing. This plasma-treats the liquid, but because the inert gas continues to be supplied to the cover housing even while the plasma is being applied, it is necessary to exhaust the air inside the cover housing to the outside. For this reason, a duct opening is provided at the bottom of the cover housing. The duct opening is connected to the outside via a pipe, and an ozone filter is provided in the pipe. Therefore, the air inside the cover housing passes through the duct opening and the pipe, and ozone is removed by the ozone filter before being exhausted to the outside. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. WO2018 / 016014 A1 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the device described in Patent Document 1, if the liquid to be treated leaks from the container in which it is held for some reason, the leaked liquid to be treated may reach the piping through the duct opening and come into contact with the ozone filter, causing the ozone filter to lose its function.

[0005] An object of the present disclosure is to provide a technology that, when the liquid to be treated leaks from a container holding the liquid, makes it possible to trap the leaked liquid to be treated near the duct opening. [Means for solving the problem]

[0006] In order to achieve the above object, the plasma irradiation device of the present disclosure includes a cover housing that defines a predetermined space, a plasma generating device that ejects plasma toward the inside of the cover housing, a gas supply device that supplies gas to the inside of the cover housing, a holding section that is provided inside the cover housing and holds the liquid to be treated, a duct opening that is provided in the lower part of the cover housing and exhausts the gas from the inside of the cover housing, and a liquid reservoir that is provided below the duct opening and accumulates the liquid. The liquid reservoir is formed in a tube shape. do. [Effects of the Invention]

[0007] According to the present disclosure, when the liquid to be treated leaks from the container in which it is held, the leaked liquid to be treated can be trapped near the duct opening. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view of an atmospheric pressure plasma irradiation device. [Figure 2] FIG. 2 is an exploded view of the plasma generating device. [Figure 3] FIG. 2 is an exploded view of the plasma generating device. [Figure 4] FIG. 2 is a cross-sectional view of a plasma generating device. [Figure 5] FIG. 1 is a perspective view of an atmospheric pressure plasma irradiation device. [Figure 6] FIG. 1 is a side view of an atmospheric pressure plasma irradiation device. [Figure 7] FIG. 1 is a side view of an atmospheric pressure plasma irradiation device. [Figure 8] FIG. 1 is a perspective view of an atmospheric pressure plasma irradiation device. [Figure 9] 1A is a perspective view of an irradiation block, and FIG. 1B is a cross-sectional perspective view taken along line BB of the irradiation block. [Figure 10] FIG. 2 is a cross-sectional view taken along line AA in FIG. [Figure 11] FIG. 2 is a block diagram of a control device. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings.

[0010] 1 shows an atmospheric pressure plasma irradiation apparatus 10 according to one embodiment of the present disclosure. The atmospheric pressure plasma irradiation apparatus 10 is an apparatus for irradiating a culture solution (an example of a "liquid to be treated") with plasma under atmospheric pressure, and includes a plasma generator 20, a cover housing 22, an opening / closing mechanism 24, a stage 26, an elevating device 28, a purge gas supply mechanism 32 (see FIG. 5), a concentration detection mechanism 34, an exhaust mechanism 36, and a control device 38 (see FIG. 11). The width direction of the atmospheric pressure plasma irradiation apparatus 10 is referred to as the X direction, the depth direction of the atmospheric pressure plasma irradiation apparatus 10 as the Y direction, and the direction perpendicular to the X direction and Y direction, i.e., the up-down direction, as the Z direction.

[0011] As shown in Figures 2 to 4, the plasma generator 20 includes a cover 50, an upper block 52, a lower block 54, a pair of electrodes 56, and a nozzle block 58. The cover 50 is generally shaped like a covered rectangular cylinder, and the upper block 52 is disposed inside the cover 50. The upper block 52 is generally shaped like a rectangular parallelepiped and is made of ceramic. A pair of cylindrical recesses 60 are formed on the lower surface of the upper block 52.

[0012] The lower block 54 also has a generally rectangular parallelepiped shape and is molded from ceramic. A recess 62 is formed in the upper surface of the lower block 54. The recess 62 is composed of a pair of cylindrical recesses 66 and a connecting recess 68 that connects the pair of cylindrical recesses 66. The lower block 54 is fixed to the lower surface of the upper block 52 while protruding from the lower end of the cover 50, and the cylindrical recesses 60 of the upper block 52 and the cylindrical recesses 66 of the lower block 54 are connected to each other. The cylindrical recesses 60 and 66 have approximately the same diameter. A slit 70 is formed in the bottom surface of the recess 62, penetrating the lower surface of the lower block 54.

[0013] Each of the pair of electrodes 56 is disposed in a cylindrical space defined by a cylindrical recess 60 in the upper block 52 and a cylindrical recess 66 in the lower block 54. The outer diameter of the electrode 56 is smaller than the inner diameters of the cylindrical recesses 60, 66. The nozzle block 58 is generally flat and is fixed to the lower surface of the lower block 54. The nozzle block 58 is formed with an ejection port 72 that communicates with the slit 70 in the lower block 54, and the ejection port 72 passes through the nozzle block 58 in the vertical direction.

[0014] The plasma generator 20 further includes a processing gas supply device 74 (see FIG. 11). The processing gas supply device 74 is a device that supplies processing gas obtained by mixing an active gas such as oxygen and an inert gas such as nitrogen at an arbitrary ratio, and is connected to the cylindrical space defined by the cylindrical recesses 60, 66 and to the upper part of the connecting recess 68 via piping (not shown). As a result, the processing gas is supplied into the recess 62 from the gap between the electrode 56 and the cylindrical recess 66 and from the upper part of the connecting recess 68.

[0015] With this structure, the plasma generator 20 ejects plasma from the nozzle 72 of the nozzle block 58. More specifically, a processing gas is supplied into the recess 62 by the processing gas supply device 74. At this time, a voltage is applied to the pair of electrodes 56 in the recess 62, and a current flows between the pair of electrodes 56. This causes a discharge between the pair of electrodes 56, which converts the processing gas into plasma. The plasma is then ejected from the nozzle 72 through the slit 70.

[0016] 5, the cover housing 22 includes an upper cover 76 and a lower cover 78. The upper cover 76 is generally cylindrical with a lid, and a through-hole (not shown) having a shape corresponding to the lower block 54 of the plasma generator 20 is formed in the lid of the upper cover 76. The cover 50 of the plasma generator 20 is fixed in an upright state to the lid of the upper cover 76 so as to cover the through-hole. Therefore, the lower block 54 and the nozzle block 58 of the plasma generator 20 protrude in the Z direction toward the inside of the upper cover 76. As a result, plasma generated by the plasma generator 20 is ejected in the Z direction from the ejection port 72 of the nozzle block 58 toward the inside of the upper cover 76.

[0017] Furthermore, roughly rectangular through-holes (not shown) are formed at three equally spaced positions on the side of the upper cover 76, and transparent glass plates 80 are disposed to cover the through-holes. This makes it possible to view the inside of the upper cover 76 through the glass plates 80.

[0018] The lower cover 78 of the cover housing 22 is generally disk-shaped and is fixed to a housing (not shown) of a mounting portion on which the atmospheric pressure plasma irradiation device 10 is mounted. The outer diameter of the lower cover 78 is larger than the outer diameter of the upper cover 76, and an annular gasket 82 having the same diameter as the upper cover 76 is disposed on the upper surface of the lower cover 78. When the upper cover 76 is slid downward by the opening / closing mechanism 24, the upper cover 76 comes into close contact with the gasket 82, and the interior of the cover housing 22 is sealed.

[0019] More specifically, as shown in Figures 6 and 7, the opening / closing mechanism 24 includes a pair of slide mechanisms 86 and an air cylinder 88. Each slide mechanism 86 includes a support shaft 90 and a slider 92. The support shaft 90 is erected on the housing of the mounting unit so as to extend in the Z direction. The slider 92 has a generally cylindrical shape and is fitted onto the support shaft 90 so as to be slidable in the axial direction of the support shaft 90. The upper cover 76 is held to the slider 92 by an upper bracket 96 and a lower bracket 98. This allows the upper cover 76 to slide in the Z direction, i.e., up and down.

[0020] The air cylinder 88 includes a rod 100, a piston (not shown), and a cylinder 102. The rod 100 is disposed so as to extend in the Z direction, and its upper end is fixed to the upper cover 76. A piston is fixed to the lower end of the rod 100. The piston is fitted into the cylinder 102 from its upper end, and moves slidably inside the cylinder 102. The cylinder 102 is fixed to the housing of the placing unit at its lower end, and a predetermined amount of air is sealed inside the cylinder 102.

[0021] This allows the air cylinder 88 to function as a damper, preventing the upper cover 76 from suddenly descending. The air pressure inside the cylinder 102 is set to a pressure that can be compressed by the weight of the components that slide together with the upper cover 76, i.e., the upper cover 76, plasma generator 20, slider 92, etc. In other words, if an operator releases the upper cover 76 while it is raised, the upper cover 76 will descend due to the weight of the upper cover 76, etc. Then, the upper cover 76 will come into close contact with the packing 82 of the lower cover 78, and the interior of the cover housing 22 will be sealed by the upper cover 76 and the lower cover 78, as shown in FIG. 8.

[0022] Furthermore, when the operator lifts the upper cover 76, the interior of the cover housing 22 is opened. A magnet 106 (see FIG. 1) is fixed to the upper surface of the upper cover 76, and when the upper cover 76 is lifted, the magnet 106 is attracted to the housing of the placement unit. In this way, by attracting the magnet 106 to the housing of the placement unit, the state in which the upper cover 76 is lifted, i.e., the state in which the cover housing 22 is open, is maintained.

[0023] The stage 26 is generally disk-shaped, and an irradiation block 180 is placed on the upper surface of the stage 26. The outer diameter of the stage 26 is smaller than the outer diameter of the lower cover 78. The stage 26 is disposed on the upper surface of the lower cover 78.

[0024] The irradiation block 180 is used to store the liquid to be treated delivered by the liquid delivery tube 120 and to generate a plasma-treated liquid by irradiating the stored liquid to be treated with plasma ejected from the plasma generator 20. The generated plasma-treated liquid is discharged from the irradiation block 180 by the drainage tube 122.

[0025] The liquid to be treated is supplied to the irradiation block 180 in the cover housing 22 through a liquid feed tube 120 using a pump (not shown) from a liquid feed supply unit (not shown) provided outside the cover housing 22. The plasma-treated liquid generated in the irradiation block 180 is drained from the irradiation block 180 using a pump (not shown) through a liquid drain tube 122 and stored in a temporary storage bottle (not shown) provided outside the cover housing 22. Therefore, through holes 134 and 136 are formed in the side surface of the lower cover 78, through which the liquid feed tube 120 and the liquid drain tube 122 pass, respectively.

[0026] Fig. 9 shows a schematic configuration of the irradiation block 180. Fig. 9(a) is a perspective view showing the overall appearance of the irradiation block 180, and Fig. 9(b) is a cross-sectional perspective view taken along line BB in Fig. 9(a). The direction from left to right is the direction in which the liquid to be treated flows.

[0027] The irradiation block 180 is made of ceramic and includes an irradiation block main body 181 having a generally rectangular parallelepiped shape. The long side direction of the irradiation block 180 is the X direction, and the short side direction is the Y direction. The irradiation block main body 181 is formed with a groove portion 183 and a storage portion 184, the surfaces of which facing the plasma generator 20 are open when the irradiation block 180 is installed in the cover housing 22.

[0028] The groove 183 has a U-shape in YZ cross section that opens upward. A bottom surface 183a that constitutes the groove 183 is curved. The YZ cross section of the groove 183 is slightly narrower than the cross-sectional shape of the liquid-feed tube 120 (see FIG. 1), and the liquid-feed tube 120, which is flexible, is fitted into the groove 183, thereby fixing the liquid-feed tube 120.

[0029] The storage section 184 stores the liquid to be treated for plasma irradiation. The storage section 184 is configured as a cylindrical recess having a side surface 184a and a bottom surface 184b. The bottom surface 184b of the storage section 184 is formed to be located lower than the bottom surface 183a of the groove section 183. The bottom surface 184b of the storage section 184 is further formed with a drainage hole 184c for discharging the plasma-treated liquid generated by irradiating the liquid to be treated with plasma from the storage section 184. The bottom surface 184b is an inclined surface that slopes downward from the side surface 184a toward the drainage hole 184c. This is to achieve the functions of quickly discharging the plasma-treated liquid from the storage section 184 and preventing, as much as possible, a state in which part of the plasma-treated liquid remains in the storage section 184 without being discharged.

[0030] In addition to the above configuration, the irradiation block main body 181 has a discharge portion 186. The discharge portion 186 is formed on the lower surface 181a of the irradiation block main body 181, protruding downward from a position including the drainage hole 184c of the storage portion 184. The discharge portion 186 has a base 186a, a flange portion 186b, and a discharge locking portion 186c, and is integrally formed with the respective components 186a to 186c connected downward. Furthermore, a through-hole 186d is formed in the center of the discharge portion 186 in the Z direction, and communicates with the drainage hole 184c of the storage portion 184.

[0031] The portion of the outer peripheral surface of the discharge part 186 that is continuous with the lower surface 181a of the irradiation block main body part 181 is the base part 186a. The diameter of the outer periphery of the discharge locking part 186c, which is formed below the base part 186a with the flange part 186b sandwiched therebetween, is larger than the diameter of the drainage tube 122 (see FIG. 1). The outer diameter of the upper part 186c1 of the discharge locking part 186c is smaller than the outer diameter of the discharge locking part 186c. As a result, when the flexible drainage tube 122 is fitted up to the upper part 186c1, the drainage tube 122 is deformed along the outer periphery of the discharge locking part 186c, and the drainage tube 122 is fixed. The base part 186a is fitted into the notch part 26a of the stage 26 (see FIG. 1), whereby the irradiation block 180 is fixed to the stage 26. In this way, since the irradiation block 180 is not fixed using a fixture, it can be easily attached to and detached from the stage 26 .

[0032] As shown in Fig. 7, the lifting device 28 includes a support rod 112, a rack 114, a pinion 116, and an electromagnetic motor 117 (see Fig. 11). A through-hole (not shown) that penetrates the lower cover 78 in the vertical direction is formed, and the support rod 112 is inserted into the through-hole. The outer diameter of the support rod 112 is smaller than the inner diameter of the through-hole, and the support rod 112 is movable in the vertical direction, i.e., in the Z direction. The lower surface of the stage 26 is fixed to the upper end of the support rod 112.

[0033] Furthermore, the rack 114 is fixed to the outer circumferential surface of the portion of the support rod 112 that extends downward from the lower cover 78 so as to extend in the axial direction of the support rod 112. The pinion 116 is meshed with the rack 114 and rotates when driven by an electromagnetic motor 117. The pinion 116 is rotatably held by the housing of the mounting unit. With this structure, when the pinion 116 is rotated by driving the electromagnetic motor 117, the support rod 112 moves in the Z direction and the stage 26 rises and falls. A measurement rod 118 is erected on the upper surface of the lower cover 78, next to the stage 26. A scale is marked on the outer circumferential surface of the measurement rod 118, and the height of the stage 26 in the Z direction, i.e., the amount of lift of the stage 26, can be visually confirmed using the scale.

[0034] As shown in Fig. 5, the purge gas supply mechanism 32 includes four air joints 130 (three are shown in the figure) and a purge gas supply device 132 (see Fig. 11). The four air joints 130 are provided at four equally spaced positions on the upper end of the side surface of the upper cover 76, and each air joint 130 opens into the interior of the upper cover 76. The purge gas supply device 132 is a device that supplies an inert gas such as nitrogen, and is connected to each air joint 130 via piping (not shown). With this structure, the purge gas supply mechanism 32 supplies an inert gas into the interior of the upper cover 76.

[0035] The concentration detection mechanism 34 includes an air joint 140, a pipe 142, and a detection sensor 144 (see FIG. 11). A through hole (not shown) is formed in the lower cover 78, communicating the top and side surfaces of the lower cover 78. An opening 146 of the through hole on the top side of the lower cover 78 is located inside the packing 82. Meanwhile, the air joint 140 is connected to an opening of the through hole on the side surface of the lower cover 78. The detection sensor 144 is a sensor that detects the oxygen concentration, and is connected to the air joint 140 via the pipe 142. With this structure, the concentration detection mechanism 34 detects the oxygen concentration inside the cover housing 22 when the cover housing 22 is sealed.

[0036] As shown in FIG. 1, the exhaust mechanism 36 includes an L-shaped pipe 150, a connecting pipe 152, and a main pipe 154. As shown in FIG. 7, the lower cover 78 is formed with a duct opening 160 that opens to both the upper and lower surfaces. The opening of the duct opening 160 on the upper surface of the lower cover 78 is formed with a tapered surface 162 whose inner diameter increases upward. In other words, when the cover housing 22 is sealed, the tapered surface 162 is inclined toward the inner wall surface of the upper cover 76. Meanwhile, the L-shaped pipe 150 is connected to the opening of the duct opening 160 on the lower surface of the lower cover 78. The main pipe 154 is connected to the L-shaped pipe 150 via the connecting pipe 152. Note that the portion of the connecting pipe 152 on the L-shaped pipe 150 side is omitted. An ozone filter 166 is disposed inside the main pipe 154. The ozone filter 166 is made of activated carbon and adsorbs ozone.

[0037] 10, an opening 150a is formed in the bottom surface of the L-shaped pipe 150 located directly below the opening on the lower surface side of the lower cover 78, and a tubular liquid reservoir 151 is connected to the opening 150a. A plug 151a is detachably attached to the lower end of the liquid reservoir 151 on the side opposite to the opening 150a. The liquid reservoir 151 is provided to collect the liquid to be treated (including the plasma-treated liquid) that leaks from the irradiation block 180 for some reason. In other words, the liquid to be treated that leaks from the irradiation block 180 falls downward from the duct opening 160 and reaches the liquid reservoir 151 from the opening 150a of the L-shaped pipe 150. The liquid to be treated that reaches the liquid reservoir 151 remains in the liquid reservoir 151 and does not flow from the L-shaped pipe 150 to the connecting pipe 152. Therefore, the liquid to be treated does not come into contact with the ozone filter 166 provided in the main pipe 154 located downstream of the connecting pipe 152. This prevents the liquid to be treated from coming into contact with the ozone filter 166, which would cause the ozone filter 166 to lose its function. Here, one possible cause of this is that the liquid supply tube 120 or the liquid drainage tube 122 becomes detached from the irradiation block 180, causing the liquid to be treated stored in the storage section 184 of the irradiation block 180 to leak out of the irradiation block 180 or leak from the liquid supply tube 120 or the liquid drainage tube 122 themselves. Note that the liquid reservoir 151 is preferably made of a transparent material so that the liquid to be treated stored therein can be observed from the outside. In this embodiment, the liquid reservoir 151 is provided with a detachable plug 151a so that the liquid to be treated that has accumulated inside the liquid reservoir 151 can be easily removed.

[0038] 11 , the control device 38 includes a controller 170 and a plurality of drive circuits 172. The plurality of drive circuits 172 are connected to the electrode 56, the process gas supply device 74, the electromagnetic motor 117, and the purge gas supply device 132. The controller 170 includes a CPU, ROM, RAM, etc., and is mainly a computer, and is connected to the plurality of drive circuits 172. As a result, the operation of the plasma generation device 20, the lifting device 28, and the purge gas supply mechanism 32 is controlled by the controller 170. The controller 170 is also connected to the detection sensor 144. As a result, the controller 170 obtains the detection result of the detection sensor 144, i.e., the oxygen concentration inside the cover housing 22.

[0039] Because irradiating a culture solution with plasma activates the culture solution, plasma is expected to be utilized in the medical field, such as in cancer treatment using plasma-irradiated culture solution. For this reason, plasma-irradiated culture solutions are produced, and it is preferable that the culture solution be irradiated with plasma under controlled conditions. With the above-described configuration, the atmospheric pressure plasma irradiation device 10 can irradiate the culture solution with plasma under predetermined conditions by placing the irradiation block 180 on the stage 26 and sealing the cover housing 22. A method for irradiating the culture solution with plasma under predetermined conditions will be described in detail below.

[0040] Specifically, first, the irradiation block 180 is placed on the stage 26. Next, the elevator 28 raises and lowers the stage 26 to a desired height. This makes it possible to set the distance between the plasma nozzle 72 and the culture solution, which serves as the object to be irradiated with the plasma, as desired. The height to which the stage 26 has been raised and lowered can be confirmed using the scale on the measuring rod 118.

[0041] Next, the upper cover 76 is lowered to seal the cover housing 22. Then, the purge gas supply mechanism 32 supplies inert gas into the cover housing 22. At this time, the concentration detection mechanism 34 detects the oxygen concentration inside the cover housing 22. After the detected oxygen concentration falls below a predetermined threshold, the plasma generator 20 sprays plasma into the cover housing 22. Note that the supply of inert gas into the cover housing 22 continues even during plasma irradiation. The liquid to be treated, adjusted to a constant flow rate, flows through the liquid feed tube 120 into the reservoir 184 of the irradiation block 180. The liquid to be treated stored in the reservoir 184 is activated by irradiating it with plasma gas from the plasma generator 20. It has been found that irradiating the liquid to be treated with plasma gas for a predetermined period of time can exert a therapeutic effect. The liquid to be treated is stored in the reservoir 184, where it is irradiated with plasma gas for a predetermined period of time. Furthermore, when the liquid to be treated is irradiated with plasma gas, natural convection occurs within the reservoir 184. This allows the liquid to be a homogeneous activated liquid that exhibits a therapeutic effect.

[0042] In this way, by supplying an inert gas to the inside of the cover housing 22, the air inside the cover housing 22 is exhausted to the outside of the cover housing 22. At this time, the oxygen concentration inside the cover housing 22 is adjusted to control the conditions that affect the plasma irradiation. Specifically, because plasma contains active radicals, when it reacts with oxygen it becomes ozone, reducing the effectiveness of the plasma irradiation. Therefore, by adjusting the oxygen concentration inside the cover housing 22, it is possible to examine the influence of oxygen concentration on the effectiveness of plasma-irradiated culture solution. Furthermore, it is possible to irradiate plasma to the culture solution under the same conditions. This makes it possible to efficiently produce plasma-treated liquid.

[0043] Furthermore, as described above, the distance between the plasma nozzle 72 and the culture solution can be set arbitrarily in the atmospheric plasma irradiation device 10. This makes it possible to examine the influence of the irradiation distance on the effect of plasma-irradiated culture solution, and to efficiently produce a plasma-treated liquid.

[0044] A duct opening 160 is also formed in the lower cover 78. Therefore, supplying an inert gas into the cover housing 22 creates a positive pressure inside the cover housing 22, and air is naturally exhausted from inside the cover housing 22. The duct opening 160 of the lower cover 78 is also formed with a tapered surface 162 whose inner diameter increases toward the upper surface of the lower cover 78. This makes it possible to promote the exhaust of gas from inside the cover housing 22. Furthermore, the exhaust mechanism 36 is provided with an ozone filter 166. This makes it possible to prevent the ozone from being exhausted to the outside, even if ozone is generated by a reaction between plasma and oxygen.

[0045] When a predetermined time has elapsed since plasma irradiation began, the plasma-treated liquid stored in the storage section 184 is discharged via the drainage tube 122. When a predetermined time has elapsed since discharge of the plasma-treated liquid from the storage section 184 began, it is determined that no plasma-treated liquid remains in the storage section 184, and discharge of the plasma-treated liquid from the storage section 184 is completed. Then, the liquid to be treated next is flowed via the liquid feed tube 120 into the storage section 184 of the irradiation block 180. Thereafter, the plasma treatment process of irradiating the liquid to be treated stored in the storage section 184 with plasma for a predetermined time, draining the plasma-treated liquid, supplying new liquid to be treated to the irradiation block 180, irradiating the liquid to be treated with plasma, and so on, is repeated until a predetermined amount of plasma-treated liquid is produced.

[0046] As described above, the atmospheric pressure plasma irradiation device 10 of this embodiment comprises a cover housing 22 that defines a predetermined space, a plasma generator 20 that sprays plasma toward the inside of the cover housing 22, a purge gas supply mechanism 32 that supplies gas to the inside of the cover housing 22, a stage 26 that is provided inside the cover housing 22 and holds the liquid to be treated, a duct opening 160 that is provided at the bottom of the cover housing 22 and exhausts gas from the inside of the cover housing 22, and a liquid reservoir 151 that is provided below the duct opening 160 and collects some of the liquid to be treated that leaks from the stage 26.

[0047] As described above, in the atmospheric plasma irradiation device 10 of this embodiment, the liquid to be treated leaking from the stage 26 collects in the liquid reservoir 151 provided near the duct opening 160 and does not leak out of the liquid reservoir 151, so that the liquid to be treated leaking from the stage 26 can be retained near the duct opening. Therefore, as in the atmospheric plasma irradiation device 10 of this embodiment, when the main pipe 154 is provided downstream of the L-shaped pipe 150 in which the liquid reservoir 151 is provided and the ozone filter 166 is provided inside the main pipe 154, the liquid to be treated leaking from the stage 26 does not reach the ozone filter 166, so that it is possible to prevent the liquid to be treated leaking from the stage 26 from contacting the ozone filter 166 and causing the ozone filter 166 to lose its function.

[0048] In this embodiment, the atmospheric pressure plasma irradiation device 10 is an example of a "plasma irradiation device." The purge gas supply mechanism 32 is an example of a "gas supply device." The stage 26 is an example of a "holding unit." A portion of the liquid to be treated that leaks from the stage 26 is an example of a "liquid."

[0049] Furthermore, the liquid reservoir 151 is formed in a tubular shape, and the tubular liquid reservoir 151 is formed in a state of extending in the vertical direction, which enables the liquid reservoir 151 to reliably catch and store the liquid to be treated that has leaked from the stage 26.

[0050] Furthermore, at least a part of the liquid reservoir 151 is made of a transparent material so that part of the liquid to be treated that has accumulated in the liquid reservoir 151 can be observed from the outside. This allows an operator to check from the outside whether or not the liquid to be treated has accumulated in the liquid reservoir 151.

[0051] The atmospheric plasma irradiation device 10 of this embodiment further includes an elevator 28 that moves the stage 26 and arbitrarily changes the distance between the stage 26 and the plasma nozzle 72 that ejects the plasma into the cover housing 22 of the plasma generator 20. This makes it possible to investigate the influence of irradiation distance on the effect of plasma-irradiated culture solution, and to efficiently produce plasma-treated liquid. The elevator 28 is an example of a "moving device."

[0052] The present disclosure is not limited to the above-described embodiment, and various modifications are possible without departing from the spirit of the present disclosure.

[0053] (1) In the above embodiment, a culture medium is used as the object to be treated, but a liquid other than a culture medium can be used as the object to be treated. Furthermore, the present disclosure can be applied not only to the medical field but also to various fields such as the industrial field.

[0054] (2) In the above embodiment, the liquid reservoir 151 is made entirely of a transparent material, but this is not limiting and the liquid reservoir 151 may be made of a partially transparent material. Furthermore, the material may be flexible or rigid.

[0055] (3) In the above embodiment, the liquid reservoir 151 has been described as storing the liquid to be treated (including the plasma-treated liquid) that has leaked from the irradiation block 180 for some reason, but the liquid reservoir 151 is not limited to the liquid to be treated that has leaked from the irradiation block 180. For example, the liquid reservoir 151 can also store the liquid to be treated that has evaporated into gas and then condensed back into liquid. In other words, the liquid reservoir 151 can store any type of liquid that flows into it. [Explanation of symbols]

[0056] 10...atmospheric pressure plasma irradiation device, 20...plasma generator, 22...cover housing, 26...stage, 28...lifting device, 38...control device, 72...spout, 120...liquid supply tube, 122...discharge tube, 132...purge gas supply device, 150...L-shaped piping, 150a...opening, 151...liquid reservoir, 151a...plug, 160...duct opening, 166...ozone filter, 180...irradiation block, 184...storage section, 186...discharge section.

Claims

1. a cover housing that defines a predetermined space; a plasma generating device that ejects plasma toward the inside of the cover housing; a gas supply device that supplies gas to the inside of the cover housing; a holding portion provided inside the cover housing and holding the liquid to be treated; a duct port provided in a lower portion of the cover housing for discharging gas from inside the cover housing; a liquid reservoir portion provided below the duct opening and configured to collect liquid; Equipped with The liquid reservoir is formed in a tubular shape. Plasma irradiation device.

2. The liquid pooled in the liquid pool contains a portion of the liquid to be treated that has leaked from the holding section. The plasma irradiation device according to claim 1 .

3. The tubular liquid reservoir is formed in a state of extending vertically. The plasma irradiation device according to claim 1 or 2.

4. At least a part of the liquid reservoir is made of a transparent member so that a part of the liquid to be treated accumulated in the liquid reservoir can be observed from the outside. The plasma irradiation device according to any one of claims 1 to 3.

5. a moving device that moves the holding part and arbitrarily changes the distance between the holding part and a plasma nozzle for ejecting plasma into the cover housing of the plasma generating device; The plasma irradiation device according to any one of claims 1 to 4, further comprising:

6. A method for producing a plasma-treated liquid, comprising: a cover housing that partitions a predetermined space; a plasma generating device that sprays plasma toward the inside of the cover housing; a gas supply device that supplies gas into the inside of the cover housing; a holding section that is provided inside the cover housing and holds the liquid to be treated; a duct opening that is provided at the bottom of the cover housing and exhausts gas from the inside of the cover housing; and a liquid reservoir section that is provided below the duct opening and collects liquid, wherein the liquid reservoir section produces a plasma-treated liquid by irradiating plasma onto the liquid to be treated held inside the cover housing using a plasma irradiation device formed in a tubular shape.

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