JP7724304B2 - Plasma irradiation device and method for producing plasma-treated liquid - Google Patents

Description

This disclosure relates to a technology for irradiating plasma onto a liquid to be treated.

Patent Document 1 describes an apparatus for plasma-treating a liquid (culture fluid) held inside a cover housing. Specifically, an inert gas is supplied to the inside of the cover housing, and when the oxygen concentration inside the cover housing falls below a predetermined value, a plasma generator sprays plasma into the inside of the cover housing. This plasma-treats the liquid, but because the inert gas continues to be supplied to the inside of 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 the pipe is equipped with an ozone filter. 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.

International Publication No. WO2018/016014 A1

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 may reach the piping through the duct opening and come into contact with the ozone filter, causing the ozone filter to lose its function.

The purpose of this disclosure is to provide a technology that makes it possible to capture leaked treated liquid near the duct opening when the treated liquid leaks from a container holding the treated liquid.

In order to achieve the above object, the plasma irradiation device of the present disclosure comprises 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 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 at the bottom of the cover housing and exhausts gas from the inside of the cover housing, and a liquid reservoir that is provided below the duct opening and accumulates the liquid , and the liquid reservoir is formed in a tubular shape .

According to the present disclosure, if the liquid to be treated leaks from the container in which it is held, it is possible to capture the leaked liquid to be treated near the duct opening.

FIG. 1 is a perspective view of an atmospheric pressure plasma irradiation device. FIG. 2 is an exploded view of the plasma generating device. FIG. 2 is an exploded view of the plasma generating device. FIG. 2 is a cross-sectional view of a plasma generating device. FIG. 1 is a perspective view of an atmospheric pressure plasma irradiation device. FIG. 1 is a side view of an atmospheric pressure plasma irradiation device. FIG. 1 is a side view of an atmospheric pressure plasma irradiation device. FIG. 1 is a perspective view of an atmospheric pressure plasma irradiation device. 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. FIG. 2 is a cross-sectional view taken along line AA in FIG. 1 . FIG. 2 is a block diagram of a control device.

The following describes in detail an embodiment of the present disclosure based on the drawings.

Figure 1 shows an atmospheric pressure plasma irradiation device 10 according to one embodiment of the present disclosure. The atmospheric pressure plasma irradiation device 10 is an apparatus for irradiating plasma to a culture solution (an example of a "liquid to be treated") 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 Figure 5), a concentration detection mechanism 34, an exhaust mechanism 36, and a control device 38 (see Figure 11). The width direction of the atmospheric pressure plasma irradiation device 10 is referred to as the X direction, the depth direction of the atmospheric pressure plasma irradiation device 10 is referred to as the Y direction, and the direction perpendicular to the X and Y directions, i.e., the up-down direction, is referred to as the Z direction.

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, with the upper block 52 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 underside of the upper block 52.

The lower block 54 is also generally rectangular and molded from ceramic. A recess 62 is formed in the upper surface of the lower block 54, and 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 underside of the upper block 52 while protruding from the lower end of the cover 50, and the cylindrical recess 60 of the upper block 52 and the cylindrical recess 66 of the lower block 54 are connected. 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 underside of the lower block 54.

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 diameter of the cylindrical recesses 60, 66. The nozzle block 58 is generally flat and is fixed to the underside of the lower block 54. The nozzle block 58 has an ejection port 72 formed therein 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.

The plasma generator 20 further includes a process gas supply device 74 (see Figure 11). The process gas supply device 74 supplies a process gas that is a mixture of an active gas such as oxygen and an inert gas such as nitrogen in any ratio, and is connected via piping (not shown) to the cylindrical space defined by the cylindrical recesses 60, 66 and to the upper part of the connecting recess 68. This allows the process gas to be supplied into the recess 62 from the gap between the electrode 56 and the cylindrical recess 66 and the upper part of the connecting recess 68.

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 to the interior of 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.

As shown in FIG. 5, the cover housing 22 also 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) shaped to fit 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 position to the lid of the upper cover 76 so as to cover the through-hole. As a result, the lower block 54 and nozzle block 58 of the plasma generator 20 protrude in the Z direction toward the interior 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 interior of the upper cover 76.

In addition, three roughly rectangular through-holes (not shown) are formed at equally spaced positions on the side of the upper cover 76, and transparent glass plates 80 are arranged to cover the through-holes. This makes it possible to see the inside of the upper cover 76 through the glass plates 80.

The lower cover 78 of the cover housing 22 is generally disk-shaped and is fixed to the housing (not shown) of the mounting portion on which the atmospheric pressure plasma irradiation device 10 is placed. The outer diameter of the lower cover 78 is larger than the outer diameter of the upper cover 76, and an annular gasket 82 of 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, sealing the interior of the cover housing 22.

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 is generally cylindrical 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.

The air cylinder 88 includes a rod 100, a piston (not shown), and a cylinder 102. The rod 100 is arranged to extend in the Z direction and is fixed at its upper end 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 within the cylinder 102. The cylinder 102 is fixed at its lower end to the housing of the mounting section, and a predetermined amount of air is sealed inside the cylinder 102.

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 compressible 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 its own weight. The upper cover 76 then tightly contacts the gasket 82 of the lower cover 78, sealing the interior of the cover housing 22 between the upper cover 76 and the lower cover 78, as shown in Figure 8.

When the operator lifts the upper cover 76, the interior of the cover housing 22 is opened. A magnet 106 (see Figure 1) is fixed to the top surface of the upper cover 76, and when the upper cover 76 is lifted, the magnet 106 attaches to the housing of the placement unit. In this way, by attracting the magnet 106 to the housing of the placement unit, the upper cover 76 is maintained in a lifted state, i.e., the cover housing 22 is maintained in an open state.

The stage 26 is generally disk-shaped, and the 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.

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

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

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

The irradiation block 180 is made of ceramic and consists of an irradiation block main body 181 that is generally rectangular. The long side of the irradiation block 180 is the X direction, and the short side is the Y direction. The irradiation block main body 181 is formed with a groove portion 183 and a storage portion 184, the surface of which facing the plasma generator 20 is open when the irradiation block 180 is installed in the cover housing 22.

The groove 183 has a U-shape in the YZ cross section that opens upward. The bottom surface 183a that forms the groove 183 is curved. The YZ cross section of this groove 183 is slightly narrower than the cross-sectional shape of the liquid delivery tube 120 (see Figure 1), and the flexible liquid delivery tube 120 is fixed in place by fitting it into the groove 183.

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 positioned 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 plasma irradiating the liquid to be treated 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.

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

The base 186a is the portion of the outer peripheral surface of the discharge section 186 that is continuous with the underside 181a of the irradiation block main body 181. The diameter of the outer periphery of the discharge locking section 186c, which is formed below the base 186a and sandwiches the flange section 186b, is larger than the diameter of the drainage tube 122 (see FIG. 1). The outer diameter of the upper section 186c1 of the discharge locking section 186c is smaller than the outer diameter of the discharge locking section 186c. As a result, when the flexible drainage tube 122 is inserted up to the upper section 186c1, the drainage tube 122 deforms along the outer periphery of the discharge locking section 186c, thereby securing the drainage tube 122. The base 186a is fitted into the notch 26a of the stage 26 (see FIG. 1), securing the irradiation block 180 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 .

As shown in Figure 7, the lifting device 28 includes a support rod 112, a rack 114, a pinion 116, and an electromagnetic motor 117 (see Figure 11). A through-hole (not shown) that penetrates in the vertical direction is formed in the lower cover 78, and the support rod 112 is inserted into this 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., the Z direction. The underside of the stage 26 is fixed to the upper end of the support rod 112.

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 the drive of the electromagnetic motor 117, the support rod 112 moves in the Z direction, and the stage 26 rises and falls. A measuring 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 measuring rod 118, and the scale makes it possible to visually check the height of the stage 26 in the Z direction, i.e., the amount of lift of the stage 26.

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 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 to the interior of the upper cover 76.

The concentration detection mechanism 34 includes an air joint 140, piping 142, and a detection sensor 144 (see Figure 11). A through-hole (not shown) is formed in the lower cover 78, connecting 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. The air joint 140 is connected to the opening of the through-hole on the side surface of the lower cover 78. The detection sensor 144 is a sensor that detects oxygen concentration, and is connected to the air joint 140 via piping 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.

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 top and bottom. The opening of the duct opening 160 on the top side of the lower cover 78 has 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 bottom side of the lower cover 78. The main pipe 154 is connected to the L-shaped pipe 150 via the connecting pipe 152. The portion of the connecting pipe 152 facing the L-shaped pipe 150 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.

As shown in Figure 10, an opening 150a is formed in the bottom surface of the L-shaped pipe 150, located directly below the opening on the underside 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, opposite the opening 150a. The liquid reservoir 151 is provided to collect the liquid to be treated (including 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 there and does not flow from the L-shaped pipe 150 to the connecting pipe 152. This prevents the liquid to be treated from contacting the ozone filter 166, which is provided in the main pipe 154 located downstream of the connecting pipe 152. This prevents the ozone filter 166 from losing its function due to the liquid to be treated contacting the ozone filter 166. Here, possible causes of the above include, for example, the liquid supply tube 120 or the liquid drainage tube 122 becoming 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 leaking 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.

As shown in FIG. 11, the control device 38 includes a controller 170 and multiple drive circuits 172. The multiple 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 is primarily a computer, including a CPU, ROM, RAM, etc., and is connected to the multiple drive circuits 172. This allows the operation of the plasma generation device 20, the lifting device 28, and the purge gas supply mechanism 32 to be controlled by the controller 170. The controller 170 is also connected to the detection sensor 144. This allows the controller 170 to obtain the detection result of the detection sensor 144, i.e., the oxygen concentration inside the cover housing 22.

Irradiating a culture medium with plasma activates the culture medium, and plasma is expected to be utilized in the medical field, such as in cancer treatment using plasma-irradiated culture medium. For this reason, plasma-irradiated culture medium is produced, and it is preferable that the culture medium be irradiated with plasma under controlled conditions. With the above-described configuration, the atmospheric pressure plasma irradiation device 10 can irradiate the culture medium with plasma under specified conditions by placing the irradiation block 180 on the stage 26 and sealing the cover housing 22. Below, a detailed description of the method for irradiating the culture medium with plasma under specified conditions is provided.

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

Next, the upper cover 76 is lowered to seal the cover housing 22. The purge gas supply mechanism 32 then 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 preset 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 while plasma is being applied. The liquid to be treated, adjusted to a constant flow rate, is then sent via the liquid delivery tube 120 to the reservoir 184 of the irradiation block 180. The liquid stored in the reservoir 184 is activated by irradiating it with plasma gas from the plasma generator 20. It has been shown that irradiating the liquid to be treated with plasma gas for a predetermined period of time can exert a therapeutic effect on the plasma-irradiated liquid. 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 treated as a homogeneous activated liquid that exhibits a therapeutic effect.

In this way, by supplying 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 plasma irradiation. Specifically, because plasma contains active radicals, when it reacts with oxygen it becomes ozone, reducing the effectiveness of plasma irradiation. Therefore, by adjusting the oxygen concentration inside the cover housing 22, it is possible to examine the effect of oxygen concentration on the effectiveness of plasma-irradiated culture solution. It also becomes possible to irradiate plasma to culture solution under the same conditions. This makes it possible to efficiently produce plasma-treated liquid.

Furthermore, as described above, in the atmospheric pressure plasma irradiation device 10, the distance between the plasma nozzle 72 and the culture solution can be set arbitrarily. This makes it possible to investigate the influence of irradiation distance on the effects of plasma-irradiated culture solution, and enables efficient production of plasma-treated liquid.

The lower cover 78 also has a duct opening 160. Therefore, when inert gas is supplied into the cover housing 22, positive pressure is created 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 also has 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.

After 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. After a predetermined time has elapsed since discharge of the plasma-treated liquid from the storage section 184 began, it is assumed 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. The next liquid to be treated with plasma is then flowed via the liquid supply tube 120 to the storage section 184 of the irradiation block 180. This plasma treatment process, which involves irradiating the liquid stored in the storage section 184 with plasma for a predetermined period of time, draining the plasma-treated liquid, supplying new liquid to the irradiation block 180, and irradiating the liquid with plasma, is then repeated until a predetermined amount of plasma-treated liquid is produced.

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 port 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 port 160 and collects a portion of the liquid to be treated that leaks from the stage 26.

In this way, in the atmospheric pressure plasma irradiation device 10 of this embodiment, the treated liquid 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, making it possible to retain the treated liquid leaking from the stage 26 near the duct opening. Therefore, in the atmospheric pressure plasma irradiation device 10 of this embodiment, where a main pipe 154 is provided downstream of the L-shaped pipe 150 in which the liquid reservoir 151 is provided and an ozone filter 166 is provided inside the main pipe 154, the treated liquid leaking from the stage 26 does not reach the ozone filter 166, and therefore it is possible to prevent the treated liquid leaking from the stage 26 from contacting the ozone filter 166 and causing the ozone filter 166 to lose its function.

Incidentally, 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 section." The portion of the liquid to be treated that leaks from the stage 26 is an example of a "liquid."

The liquid reservoir 151 is formed in a tube shape, and the tube-shaped liquid reservoir 151 is formed to extend vertically. This allows the liquid reservoir 151 to reliably catch and store the liquid to be treated that leaks from the stage 26.

In addition, at least a portion of the liquid reservoir 151 is made of a transparent material so that a portion of the liquid to be treated that has accumulated in the liquid reservoir 151 can be observed from the outside. This allows the operator to check from the outside whether or not the liquid to be treated has accumulated in the liquid reservoir 151.

In addition, the atmospheric pressure plasma irradiation device 10 of this embodiment further includes an elevator device 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 effects of plasma-irradiated culture fluid, enabling efficient production of plasma-treated liquid. Incidentally, the elevator device 28 is an example of a "moving device."

Note that this disclosure is not limited to the above embodiments, and various modifications are possible without departing from its spirit.

(1) In the above embodiment, a culture medium is used as the object to be treated, but it is possible to use a liquid other than a culture medium 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.

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

(3) In the above embodiment, the liquid reservoir 151 was described as storing the liquid to be treated (including plasma-treated liquid) that has leaked from the irradiation block 180 for some reason. However, 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 to be treated that has evaporated into a gas and then condensed back into a liquid can also be stored in the liquid reservoir 151. In other words, the liquid reservoir 151 can store any type of liquid that flows into it.

10...atmospheric pressure plasma irradiation device, 20...plasma generator, 22...cover housing, 26...stage, 28...lifting device, 38...control device, 72...nozzle, 120...liquid supply tube, 122...liquid drainage 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 (6)

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. 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 . The tubular liquid reservoir is formed in a state of extending vertically.
The plasma irradiation device according to claim 1 or 2 . 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 . The plasma irradiation device according to any one of claims 1 to 4 , further comprising a moving device that moves the holding part and arbitrarily changes the distance between the holding part and a plasma nozzle into the inside of the cover housing of the plasma generating device. 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.