JP2021090687A - Plasma sterilizer - Google Patents

Abstract

To provide a plasma sterilizer that can continuously and stably performs plasma sterilization in a mild condition without causing quality deterioration, for a small object such as a granular (granule-like) or powdery agricultural product, an object having not only a simple spherical shape, but also a complicated shape such as a flat shape, a confetti shape and a spindle shape, and objects of various sizes.SOLUTION: A plasma sterilizer for sterilizing an object by plasma generated by voltage impression between electrodes under a raw material gas atmosphere comprises: counter electrodes comprising a plate-like upper electrode and lower electrode opposed at an interval in a vertical direction; and a housing part having a bottom face formed from a plate-like insulation material or the lower electrode, and having a partition wall body in the outer periphery. The housing part includes: housing means arranged between the counter electrodes and pivotally supported in a state of housing the object in the housing part; supply means of supplying the object to the interval; and control means of controlling residence and discharge in the housing means of the object by changing a shaft center pivotally supporting the housing means.SELECTED DRAWING: Figure 1

Description

The present invention relates to a plasma sterilizer that sterilizes using plasma, and in particular, small objects such as granules and powders, and not only simple spherical shapes but also flat shapes, gold flat sugar shapes, and spindle shapes. The present invention relates to a plasma sterilizer that can reliably sterilize objects having a complicated shape and objects of various sizes.

Plasma sterilization, which sterilizes an object using plasma, has a wide range of applications, and its application fields are steadily expanding. One of the expected fields of application is sterilization of agricultural products in the agricultural field.

Agricultural products are often transported over long distances, and microbial propagation is a problem at that time. This is because various bacteria, filamentous fungi, etc. derived from soil and growing environment are attached to agricultural products, and these have a great influence on the deterioration of agricultural products.

Such agricultural products include seeds in particular. Seeds have not only simple spherical shapes but also many complex shapes such as flat seeds such as carrots and tomatoes. When such seeds are sown with bacteria, filamentous fungi, viruses, etc. attached to the surface, they proliferate after sowing and adversely affect the growth, causing stunted growth and withering. In addition to seeds, granular (granular) or powdery agricultural products such as grains used as food materials also cause deterioration of products due to adhering contaminated microorganisms being mixed into products by food processing. ..

As a technique for dealing with such a problem, so far, hot water sterilization, dry heat sterilization, and chemical sterilization have been mainly performed for the purpose of sterilizing and disinfecting microorganisms attached to seeds.

For example, in hot water sterilization, seeds are sterilized by immersing the seeds in hot water at about 50-60 ° C for several tens of minutes. In dry heat sterilization, seeds are placed in a dry air atmosphere of about 70 to 80 ° C for several days for sterilization. In chemical sterilization, sterilization is performed by adding and spraying a chemical that is compatible with fungi and the like existing on the surface of the object.

However, in the above-mentioned hot water sterilization, the seeds are soaked in hot water for about several tens of minutes, so that the seeds may be deteriorated and the germination rate may be lowered due to high temperature and moisture.

Further, in the above-mentioned dry heat sterilization, the seeds are exposed to a high temperature dry air atmosphere for several days, so that the seeds are deteriorated and germinated by being exposed to a high temperature environment for a long time as in the case of hot water sterilization. It may cause a decrease in the rate.

Further, in sterilization using the above-mentioned chemicals, deterioration due to high temperature can be avoided, but it is necessary to select a chemical suitable for the fungus to be sterilized. In addition, if the same drug is used for a long period of time, drug-resistant bacteria are generated, which contaminate the seeds, and there is a risk that the drug will not be effective in disinfecting the seeds.

Similar to seeds, heat sterilization and steam sterilization are mainly used for granular and powdered agricultural products other than seeds. However, there is a demerit that sterilization inevitably deteriorates agricultural products such as color, taste, and texture due to temperature and moisture. In addition, since many agricultural products dislike water, the sterilization techniques that can be used are limited. Further, when such an agricultural product is sterilized by using a chemical, in addition to deterioration of color, taste, texture and the like due to the chemical, a problem of residual chemical in the agricultural product also occurs. Also, the types of drugs that can be used are limited to those approved as food additives.

Under such circumstances, as a sterilization method that can achieve both safety and sterilization even for granular and powdered agricultural products, sterilization using plasma that does not directly wet the object with water or the like and does not require chemicals is performed. Realization is desired.

As a conventional plasma sterilizer capable of sterilizing such granular and powdery agricultural products, for example, a powder or granular material having a low water content orbiting in a cyclone is sterilized or modified at a low temperature by atmospheric plasma. There is one (see Patent Document 1). Further, although different from the purpose of sterilizing agricultural products, there is a fine particle treatment method for the purpose of surface-modifying fine particles (fine powder). For example, a step of supplying gas to a plasma treatment apparatus and plasma treatment of the gas. The step of supplying particles to the supply path to the device and supplying the particles into the plasma processing device together with the gas flow, and between the pair of electrodes arranged so as to face the outlet in the plasma processing device of the supply path. There is also a fine particle treatment method including a step of generating plasma so as to surround the outlet (see Patent Document 2).

Further, a counter electrode composed of an upper electrode and a lower electrode facing each other with a gap in the vertical direction, a supply means for supplying the object from the center of the upper or lower electrode toward the gap, and the lower portion. There is also a plasma sterilizer provided with a discharge means for discharging the object to the outside from the center of the electrode along the outer periphery (see Patent Document 3).

Japanese Unexamined Patent Publication No. 2014-68 Japanese Unexamined Patent Publication No. 2006-68589 International release WO2016 / 190436

However, in the conventional plasma sterilizer, for example, in Patent Document 1, since the powder or granular material which is the object is irradiated with plasma in a situation where it orbits randomly in the cyclone, it is probabilistically There is a problem that the object that is actually irradiated with plasma and the object that is not irradiated coexist, the degree of plasma irradiation is biased, and uniform and sufficient sterilization cannot be stably performed for all objects. It was.

Further, for example, in Patent Document 2, although the purpose is different from the purpose of sterilizing agricultural products, the outlet is surrounded between a pair of electrodes arranged so as to face the outlet in the plasma processing apparatus of the supply path. Plasma is generated in the surface to modify the surface of fine particles (fine powder), that is, plasma is locally generated only at both ends of the outlet between the pair of electrodes to generate fine particles (fine powder). Since the surface is modified, even if the crop is used as fine particles, the local plasma may cause some crops to be sterilized and some not to be sterilized, resulting in sparse sterilization of the crop. Therefore, there is a problem that the sterilization is uneven and insufficient.

Further, for example, in Patent Document 3, the purpose is to sterilize small agricultural products such as seeds, but especially for flat-shaped seeds, the movement of seeds becomes irregular, so that plasma is used. Some crops are sterilized and some are not sterilized, resulting in sparsely sterilized crops, resulting in uneven and inadequate sterilization.

Among the agricultural products to be sterilized, especially seeds, there are many not only simple spherical shapes but also complicated shapes such as flat shape, konpeito shape, and spindle shape, and those of various sizes. In particular, the current technology for uniformly and uniformly sterilizing seeds of various sizes and complex shapes such as flat shape, konpeito shape, and spindle shape is currently available. Not known.

The present invention has been made to solve the above problems, and is not limited to small objects such as granular (granular) and powdery agricultural products, and also simple spherical shapes, as well as flat shapes, konpeito shapes, and konpeito shapes. The purpose is to provide a plasma sterilizer that can continuously and stably perform plasma sterilization under mild conditions without degrading the quality even for complicated shapes such as spindle shapes and those of various sizes. To do.

The plasma sterilizer disclosed in the present application is a plasma sterilizer that sterilizes an object by plasma generated by applying a voltage between electrodes in a raw material gas atmosphere, and is a plate-shaped upper electrode facing each other with a gap in the vertical direction. It is composed of a counter electrode composed of a lower electrode and a storage portion having a bottom surface formed of a plate-shaped insulating material or the lower electrode and having a partition body on the outer periphery, and the storage portion is arranged between the counter electrodes. The storage means that is pivotally supported with the object stored in the storage portion, the supply means that supplies the object toward the gap, and the axial center that pivotally supports the storage means are changed. It is provided with a control means for controlling retention and discharge of an object in the storage means.

As described above, the plasma sterilizer disclosed in the present application is formed of a counter electrode composed of a plate-shaped upper electrode and a lower electrode facing each other with a gap in the vertical direction, and a plate-shaped insulating material or the lower electrode on the bottom surface. , A storage unit including a partition body provided on the outer periphery, the storage unit is arranged between the counter electrodes, and is axially supported in a state where an object is stored in the storage unit, and in the gap. Toward this, a supply means for supplying the object and a control means for controlling the retention and discharge of the object in the storage means by changing the axis supporting the storage means are provided. By the control means, the object is maintained at a constant residence time in the storage means, and after being sufficiently sterilized by plasma sterilization, discharge to the outside is promoted, and the object is in the form of powder or the like. Even if it is a fine one, not only a simple spherical shape but also a complicated shape such as a flat shape, a sterilized sugar shape, and a spindle shape, and a shape of various sizes are all. Plasma sterilization can be continuously and stably performed on the object under mild conditions without deteriorating the quality.

In the plasma sterilizer disclosed in the present application, if necessary, the storage means includes guide fins radially placed as the partition wall, and the storage means swings with respect to the counter electrode. The control means changes the axis to control the traveling direction of the swing. In this way, the storage means includes guide fins radially placed as the partition wall, the storage means swings with respect to the counter electrode, and the control means changes the axis. By controlling the traveling direction of the swing, the guide fin functions as a barrier in one traveling direction by controlling the traveling direction of the swing by the control means, and the object is moved from the storage means. In addition to exhibiting the action of staying without being discharged, the guide fin functions as an opening in another traveling direction, and the object exhibits the action of discharging from the storage means, so that the object is fine such as powder. Even if it is a simple shape, not only a simple spherical shape but also a complicated shape such as a flat shape or a cube shape can be relaxed with respect to all the above-mentioned objects by a simple configuration. Plasma sterilization can be performed continuously and stably without deteriorating the quality under the conditions.

Further, in the plasma sterilizer disclosed in the present application, if necessary, the storage means is opened in a frame body portion where the storage means is arranged at the outer end portion of the insulating material as the partition wall body and a part of the frame body portion. The control means is provided with a shape-shaped discharge port, and the control means changes the axis to control the inclination angle of the storage means. As described above, the storage means includes a frame body portion arranged at the outer end portion of the insulating material as the partition wall body, and an opening-shaped discharge port in a part of the frame body portion, and the control means Since the tilt angle of the storage means is controlled by changing the axis, one axial state in which the axis is changed by the control means, for example, the storage means is not tilted in the horizontal direction. When maintained, the object exhibits an action of staying in the frame portion, and when another axial state, for example, the storage means is tilted from the horizontal direction, the object becomes said. It has the effect of discharging from the discharge port, and even if the object is a fine object such as a powder, it can be formed into a complex shape such as a flat shape or a cube shape as well as a simple spherical shape. On the other hand, with a simple structure, it is possible to continuously and stably perform plasma sterilization on all the objects under mild conditions without deteriorating the quality.

Further, in the plasma sterilizer disclosed in the present application, the supply means supplies the raw material gas together with the object, if necessary. In this way, the concentration of the raw material gas supplied by the supply means is increased between the upper and lower electrodes in which the object is present, so that all the objects pass through the high-concentration plasma generation region. Therefore, even if the object is a fine object such as powder, not only a simple spherical shape but also a complicated shape such as a flat shape or a cube shape can be applied to all objects. On the other hand, with a simple structure, sterilization can be performed reliably.

Further, the plasma sterilizer disclosed in the present application includes a discharge position control unit formed by sealing a liquid dielectric between the counter electrodes, if necessary. In this way, the dielectric constant decreases at the position where plasma is generated between the counter electrodes due to the action of the liquid dielectric material, and the next plasma generation position sequentially shifts to other adjacent positions with high dielectric constant. Since the discharge is controlled in this way, the generation of arc discharge is suppressed, stable and gentle discharge is continuously generated between the counter electrodes, and the gentle discharge is such that the object is not damaged. Plasma sterilization can be maintained in the state.

The block diagram of the plasma sterilizer which concerns on 1st Embodiment of this invention is shown. The block diagram of the plasma sterilizer which concerns on 1st Embodiment of this invention is shown. An explanatory diagram of the swinging operation of the plasma sterilizer according to the first embodiment of the present invention is shown. The block diagram of the plasma sterilizer which concerns on 1st Embodiment of this invention is shown. The block diagram including the mesh electrode of the plasma sterilizer which concerns on 1st Embodiment of this invention is shown. The block diagram including the mesh electrode of the plasma sterilizer which concerns on 1st Embodiment of this invention is shown. The block diagram of the storage means of the plasma sterilizer which concerns on 2nd Embodiment of this invention is shown. An explanatory diagram of the swinging operation of the plasma sterilizer according to the second embodiment of the present invention is shown. An explanatory diagram of the swinging operation of the plasma sterilizer according to the second embodiment of the present invention is shown. The block diagram of the laminated stack type of the plasma sterilizer which concerns on 2nd Embodiment of this invention is shown. The block diagram of the plasma sterilizer which concerns on 3rd Embodiment of this invention is shown.

(First Embodiment)
Hereinafter, the plasma sterilizer according to the first embodiment will be described with reference to FIGS. 1 to 6.

As shown in FIG. 1, the plasma sterilizer according to the present embodiment is a plasma sterilizer that sterilizes an object 100 by plasma generated by applying a voltage between electrodes in a raw material gas atmosphere, and is a plasma sterilizer that sterilizes an object 100 in the vertical direction. A counter electrode 1 composed of a plate-shaped upper electrode 11 and a lower electrode 12 facing each other across a gap A, and a bottom surface 21 formed of a plate-shaped insulating material or a lower electrode 12, and a partition body 22 provided on the outer periphery. The storage unit 23 is composed of a storage unit 23, and the storage unit 23 is arranged between the counter electrodes 1 and is axially supported with the object 100 stored in the storage unit 23 toward the storage means 2 and the gap A. The supply means 3 for supplying the object 100 and the control means 4 for controlling the retention and discharge of the object 100 in the storage means 2 by changing the axial center 41 supporting the storage means 2 are provided. It is a composition. Further, as a means for applying an AC voltage to the counter electrode 1, an AC power supply 200 and a collection unit 300 for accumulating and collecting the object 100 discharged from the storage means 2 at the lower portion of the lower electrode 12 are provided. Is.

The shapes of the upper electrode 11 and the lower electrode 12 constituting the counter electrode 1 are not particularly limited as long as they are plate-shaped, and may be, for example, a disk shape or a polygonal shape. The material of the counter electrode 1 is not particularly limited as long as it is a commonly used metal electrode, and for example, an aluminum electrode can be used.

The AC power supply 200 that supplies power to the counter electrode 1 is not particularly limited as long as the applied voltage is AC, and a low frequency power supply or a high frequency power supply (RF) can be used. For example, an AC power supply having a frequency band of several tens of Hz to several hundreds of MHz and a voltage of 1 to 10 kV can be used. Further, as the collection unit 300, a saucer such as a plastic tray made of resin can be used, and the object 100 such as seeds can be stored and collected without being damaged.

The storage means 2 may have the same size as the counter electrode 1 or may have a different size. That is, the surface area may be smaller or larger than that of the counter electrode 1. The arrangement position of the storage means 2 is not particularly limited, but as shown in FIG. 1A, it can be placed on the lower electrode 12. In addition to this, as shown in FIG. 1B, the upper electrode 11 and the lower electrode 12 can be installed between the electrodes without contacting each other.

The bottom surface 21 of the storage unit 23 constituting the storage means 2 can be formed of a plate-shaped insulating material. The shape of this plate-shaped insulating material is not particularly limited, but a mesh sheet can be used. By using this mesh sheet, it is possible to mesh even complicated shapes such as flat shape, konpeito shape, and spindle shape, which are difficult to irradiate plasma uniformly, and objects 100 of various sizes. Plasma irradiation from the upper electrode 11 and the lower electrode 12 can be efficiently provided by the voids arranged on the ground.

In addition to forming the bottom surface 21 of the bottom surface 21 with the plate-shaped insulating material shown in FIG. 1, the storage portion 23 constituting the storage means 2 is formed of the plate-shaped insulating material as shown in FIG. 2 (a). It is also possible to form it as the upper surface portion of the lower electrode 12 without using an insulating material, and a simpler configuration can be made depending on the application.

The supply means 3 supplies the object 100 toward the gap A, and the supply method thereof is not particularly limited, but the object is, for example, using pressurization by various injectors or pumps. The object 100 can be supplied toward the gap A.

In addition to this, the supply means 3 can also supply the object 100 from the gap in the mesh of the upper electrode 11 toward the gap A by the configuration in which the upper electrode 11 has a mesh structure. Further, the supply means 3 has a structure in which the upper electrode 11 is formed in a tapered shape having a recessed center, and by providing a gap in the central portion thereof, the gap A is formed from the gap in the central portion of the upper electrode 11. The object 100 can also be supplied toward.

The control means 4 controls the retention and discharge of the object 100 in the storage means 2 by changing the axis 41 that pivotally supports the storage means 2. The mode for changing the axis 41 is not particularly limited, but for example, the accommodating means 2 swings with respect to the counter electrode 11 and the traveling direction of the swing is changed by changing the axis 41. Can be controlled.

For example, as shown in FIG. 2B, the storage means 2 includes guide fins 22a radially placed as the partition wall 22, and the storage means 2 swings with respect to the counter electrode 11. At the same time, the control means 4 changes the axis 41 to control the forward direction and the reverse direction, which is the traveling direction of the swing.

The storage means 2 swings with respect to the counter electrode 11, but the storage means 2 swings in a different movement or direction from the counter electrode 11, and the counter electrode It includes swinging in the same movement and direction as in 11.

As shown in FIG. 3A, the guide fins 22a are radially placed as the partition wall 22, and the material thereof is damaged when the seeds of the agricultural product as the object 100 collide with each other. A resin or the like that does not become is suitable.

Further, the center B'of the storage means 2 (circular center if it is circular) is eccentrically configured with the center B (circular center if it is circular) of the lower electrode 12 (upper electrode 11).

The storage means 2 vibrates in two directions (xy direction, vertical and horizontal directions) on a plane as a swinging operation performed on the counter electrode 1, and the control means 4 has the 2. Controls the phase of vibration in the direction. The vibration in these two directions may be a vibration operation that is not rotation, or may be a vibration operation that is rotation, and is not particularly limited as long as the vibration occurs in two directions on the plane. For example, as shown in FIG. 3A, the storage means 2 can rotate with the center B of the lower electrode 12 (upper electrode 11) as the center of rotation. That is, the locus of the center B'of the storage means 2 is formed along a concentric circle centered on the center B of the lower electrode 12 (upper electrode 11).

Further, when the storage means 2 rotates, the control means 4 changes the rotation direction by the axis 41 so as to be either a forward direction or a reverse direction to control the traveling direction of the swing. can do.

For example, as shown in FIG. 3B, the control means 4 controls the storage means 2 to rotate in the forward direction R, so that the guide fins 22a have an elevation angle with respect to the rotation direction. Therefore, the gap between the guide fins 22a cannot be seen from the inside of the storage means 2, the outer periphery of the storage means 2 is shielded, the discharge of the object 100 is suppressed, and the object 100 is stored in the storage means 2. The action of pushing the object 100 works inside, and the object 100 is scraped up inside the storage means 2, and uniform sterilization can be performed with a sufficient plasma irradiation time.

Further, as shown in FIG. 3C, the control means 4 controls the storage means 2 to rotate in the reverse direction L, so that the guide fins 22a have a depression angle with respect to the rotation direction. Therefore, the gap between the guide fins 22a can be seen from the inside of the storage means 2, the outer periphery of the storage means 2 is opened, the discharge of the object 100 is promoted, and the object 100 is stored in the storage means 2. The action of discharging to the outside works, and the object 100 can be discharged to the outside after being uniformly sterilized inside the storage means 2 for a sufficient plasma irradiation time as described above.

As described above, the control means 4 controls the storage means 2 to rotate in the forward direction R by the above-mentioned series of control operations, so that the control means 4 is located around the center B between the electrodes of the upper electrode 11 and the lower electrode 12. Uniform sterilization is performed by assembling the objects 100 and intensively performing uniform sterilization under a sufficient plasma irradiation time, and then performing control to rotate the storage means 2 in the reverse direction L. The object 100 is discharged to the outside.

The control performed by the control means 4 is not limited to the control direction related to the forward direction R and the reverse direction L described above, and the control direction is freely designed according to the shape and size of the object 100. It is possible. For example, depending on the type of the object 100, whether the object 100 is rotated in the forward direction R or in the reverse direction L first depending on whether the object 100 is a spherical seed or a flat seed. It is possible to set to.

By the control of the control means 4, the guide fin 22a has both an action of temporarily storing the object 100 in the storage means 2 and an action of discharging the object 100 to the outside from the storage means 2, and is in the form of granules or powder. Not only small objects such as 100, and even simple spherical shapes, but also complex shapes such as flat shape, konpeito shape, and spindle shape, and objects of various sizes, regardless of their shape. Regardless of the above, it is possible to reliably sterilize every corner of the object 100 by a simple operation.

By controlling the traveling direction of the swing of the storage means 2 by the control means 4, the guide fin 22a functions as a barrier in one traveling direction (forward direction R), and the object 100 is discharged from the storage means 2. The object 100 is sufficiently plasma-irradiated during the residence period to perform uniform sterilization, and the guide fin 22a opens in another traveling direction (reverse direction L). The object 100 exhibits an action of discharging from the storage means 2, and even if the object 100 is a fine object such as a powder, it is not only a simple spherical shape but also flat. Even for complex shapes such as shapes, konpeito shapes, and spindle shapes, and for shapes of various sizes, the quality of all 100 objects deteriorates under mild conditions due to the simple configuration. Plasma sterilization can be performed continuously and stably without causing it.

Further, as shown in FIG. 4, a plurality of counter electrodes 1 can be arranged in series as a configuration (stacked stack type) in which the above-mentioned counter electrodes 1 are arranged in a plurality of stages and are connected to one axis 41 in a plurality of stages. is there. Due to this laminated stack type configuration, the object 100 is sequentially supplied from the uppermost counter electrode 1 and continuously moves between the counter electrode 1 and each stage of the storage means 2, resulting in substantial sterilization. It is possible to secure the processing time and perform sterilization quickly and efficiently.

Further, as shown in FIG. 5A, an upper mesh electrode 11a facing the upper electrode 11 is arranged between the upper electrode 11 and the lower electrode 12, and between the upper electrode 11 and the upper mesh electrode 11a. An upper AC power source 200a for applying a voltage to the power supply 200a can be arranged.

Similarly, as shown in FIG. 5A, a lower mesh electrode 12a facing the lower electrode 12 is arranged between the electrodes of the upper electrode 11 and the lower electrode 12, and the electrodes of the lower electrode 12 and the lower mesh electrode 12a are arranged. A lower AC power supply 200b to which a voltage is applied can be arranged between them.

The presence or absence of grounding of the upper mesh electrode 11a and the lower mesh electrode 12a is not particularly limited, but each or one of them may be grounded.

As shown in FIG. 5A, the storage means 2 is arranged between the electrodes of the upper mesh electrode 11a and the lower mesh electrode 12a. In this configuration, it is preferable to use a mesh sheet formed of the above-mentioned plate-shaped insulating material for the bottom surface 21 of the storage means 2.

By applying a voltage to the upper AC power supply 200a, a discharge is generated between the upper electrode 11 and the upper mesh electrode 11a, and plasma P is generated. Further, by applying a voltage to the lower AC power supply 200b, a discharge is generated between the lower electrode 12 and the lower mesh electrode 12a, and plasma P is generated.

As shown in FIG. 5B, the plasma P generated in the vicinity of the upper electrode 11 passes so as to leak out from the mesh gap of the mesh of the upper mesh electrode 11a, and passes through the upper surface of the bottom surface 21 of the storage means 2. Flow toward. Further, as shown in FIG. 5B, the plasma P generated in the vicinity of the lower electrode 12 passes so as to leak out from the mesh gap of the mesh of the lower mesh electrode 12a, and passes through the lower surface of the storage means 2. Further, since the bottom surface 21 of the storage means 2 is composed of a mesh sheet formed of a plate-shaped insulating material, the bottom surface 21 of the storage means 2 also leaks from the mesh gap of the mesh of the bottom surface 21 of the storage means 2. Pass through and rise.

In this way, the plasma P generated in the vicinity of each of the upper electrode 11 and the lower electrode 12 passes so as to leak out from the mesh gap of the mesh of the upper mesh electrode 11a and the lower mesh electrode 12a, and the storage means 2 It will flow from the vertical direction toward the upper surface of the bottom surface 21. As a result, as shown in FIG. 5C, the plasma P reliably irradiates the object 100 rolling into the storage means 2 from the vertical direction, and the object 100 reliably irradiates the object 100 with the storage means 2. After uniform sterilization is performed inside the plasma for a sufficient plasma irradiation time, it can be discharged to the outside.

In particular, when the size of the object 100 is large, the gap A, which is the distance between the upper electrode 11 and the lower electrode 12, is set long in order to secure a space for accommodating the object 100, and the upper electrode 11 and the lower portion Even when the discharge distance between the electrodes 12 is long, the upper mesh electrode 11a and the lower mesh electrode 12a can stably generate plasma P in the vicinity of the upper electrode 11 and the lower electrode 12. Even when the gap A, which is the distance between the upper electrode 11 and the lower electrode 12, is long, it can be discharged to the outside after uniform sterilization is performed inside the storage means 2 for a sufficient plasma irradiation time. ..

Further, a voltage can be further applied between the electrodes of the upper mesh electrode 11a and the lower mesh electrode 12a described above.

For example, as shown in FIG. 6A, a central power supply 200c for applying a voltage can be arranged between the electrodes of the upper mesh electrode 11a and the lower mesh electrode 12a described above. The central power supply 200c is a power supply that applies a voltage in which direct current, alternating current, or both are superimposed. In FIG. 6, for convenience of explanation, the central power supply 200c is described as an AC power supply as an example. The applied voltage of the central power supply 200c is not particularly limited, but it is desirable to set it lower than the applied voltage of the upper AC power supply 200a and the lower AC power supply 200b so that the voltage does not cause discharge. As a result, damage to the object 100 during the sterilization process can be further suppressed, and higher quality sterilization can be performed.

With this configuration, as shown in FIG. 6A, by applying a voltage to the upper AC power supply 200a, a discharge is generated between the upper electrode 11 and the upper mesh electrode 11a, and plasma P is generated. Further, by applying a voltage to the lower AC power supply 200b, a discharge is generated between the lower electrode 12 and the lower mesh electrode 12a, and plasma P is generated.

Further, as shown in FIG. 6B, the plasma P generated in the vicinity of each of the upper electrode 11 and the lower electrode 12 is formed by applying a voltage to the central power supply 200c to form the upper mesh electrode 11a and the lower mesh electrode 12a. It is promoted to pass through the gaps of the mesh of the mesh so as to leak out, and flow from the vertical direction at a high density toward the upper surface of the bottom surface 21 of the storage means 2.

As a result, as shown in FIG. 6C, the plasma P irradiates the object 100 rolling into the storage means 2 at a high density from the vertical direction, and the object 100 is the storage means. After performing high-density and uniform sterilization inside 2 with a sufficient plasma irradiation time, it can be discharged to the outside.

The type of the object 100 to be sterilized by the plasma sterilizer according to the first embodiment is not particularly limited, and is not only a simple spherical shape but also a complicated shape such as a flat shape, a konpeito shape, and a spindle shape. It is possible to target objects of various sizes. Further examples of such complex shapes include bell shape, ship shape, arm shape, curved ball shape, cylindrical shape, elliptical shape, human heart shape, convex lens shape, line shape, rod shape, crystal shape, and spherical shape. , Low cone shape, papilla shape, plaque shape, prickle shape, direct prickle shape, peeling shape, pit shape / low hill shape, egg shape, kidney shape, circular kidney shape, spiral shape, square shape, distorted sphere shape (The diameter is almost the same everywhere, but the shape is uneven) and the like.

From each of the above configurations, in the plasma sterilizer according to the first embodiment, the control means 4 allows the object 100 to maintain a constant residence time in the storage means 2, and plasma irradiation is sufficient. After being sterilized, the discharge to the outside is promoted, and even if the object 100 is a fine substance such as powder, not only a simple spherical shape but also a flat shape, a konpeito shape, etc. And for complex shapes such as spindle shapes and for all objects of various sizes, continuous and stable plasma sterilization under mild conditions without degrading quality. It can be performed.

Further, in the present plasma sterilizer, the supply means 3 can supply the raw material gas together with the supply of the object 100. In this case, since the concentration of the raw material gas supplied by the supply means 3 is filled between the upper electrode 11 and the lower electrode 12 in which the object 100 is present, all the objects 100 are more reliable. Even if the object 100 is fine, such as powder, it will pass through a high-concentration plasma generation region, and not only a simple spherical shape, but also a flat shape, a konpeito shape, a spindle shape, etc. It is possible to reliably sterilize all objects 100 with a simple structure, even for objects having a complicated shape or various sizes.

That is, since the concentration of the raw material gas supplied by the supply means 2 is locally increased between the central portions of the upper electrode 11 and the lower electrode 12, all the objects 100 have a high concentration of plasma. It passes through the generation region, and even if the object 100 is a fine object such as powder, all the objects 100 can be reliably sterilized regardless of the shape.

It is also possible for the supply means 3 to supply cold air or fine ice together with the supply of the object 100. In this case, the object 100 can suppress the thermal stress received from the plasma discharge during sterilization as much as possible, and it becomes possible to obtain a higher quality object 100 after sterilization.

(Second embodiment)
Hereinafter, the plasma sterilizer according to the second embodiment will be described with reference to FIGS. 7 to 10.

The second embodiment includes the counter electrode 1, the accommodating means 2, the supply means 3, and the control means 4, as in the first embodiment described above, and is further shown in FIG. 7. As described above, the storage means 2 includes a frame body portion 22b arranged at the outer end portion of the insulating material as the partition wall body 22, and an opening-shaped discharge port 22c in a part of the frame body portion 22b. The control means 4 has a configuration in which the axis 41 is changed to control the inclination angle of the storage means 2.

The change of the axis 41 is not particularly limited as long as the storage means 2 is tilted. For example, the axis 41 may be tilted as it is, or the axis 41 may be vibrated or expanded / contracted. You may let it.

As shown in FIG. 7, the storage means 2 includes a frame body portion 22b arranged at the outer end portion of the insulating material. The shape of the frame body portion 22b is not particularly limited as long as it is arranged at the outer end portion of the storage means 2. For example, as shown in FIG. 7, when the bottom portion 21 of the storage means 2 is formed of a rectangle or a square, the frame body portion 22b is on the outer edge of the rectangle or square at the outer end of the storage means 2. Is arranged in. In addition to this, as shown in FIG. 8A, when the bottom portion 21 of the storage means 2 is formed in a circular shape or an elliptical shape, the frame body portion 22b is outside the storage means 2. It is arranged on a circular or elliptical outer circle at the end.

The position of the discharge port 22c is not particularly limited as long as it is arranged in a part of the frame body portion 22b. As shown in FIG. 8A, the bottom portion 21 of the storage means 2 may be formed in a circular shape, a rectangular shape, or a square shape, and the upper electrode 11 may have a mesh structure. The object 100 can be supplied between the electrodes of the upper electrode 11 and the lower electrode 12 through the gap of the mesh of the upper electrode 11.

The control means 4 swings the storage means 2 to sterilize the object 100 with plasma for a certain period of time. This swing may be a vibration operation in the vertical and horizontal directions, or may be a rotational operation. Then, after performing plasma sterilization for a certain period of time, the control means 4 controls to incline the axis 41 as shown in FIG. 8B, and externally removes the object 100 from the discharge port 22c. Discharge to.

As described above, the storage means 2 includes a frame body portion 22c arranged at the outer end portion of the insulating material as the partition wall body 22, and an opening-shaped discharge port 22c in a part of the frame body portion 22c. Since this control means changes the axis and controls the inclination angle of the storage means 2, one axis state in which the axis is changed by this control means, for example, the storage means. When 2 is maintained in the horizontal direction without inclination, the object 100 exhibits an action of staying in the frame body portion 22c, and another axial state, for example, the storage means 2 is inclined from the horizontal direction. When this is done, the object 100 exhibits an action of discharging from the discharge port 22c, and even if the object 100 is a fine object such as a powder, it is not only a simple spherical shape but also a simple spherical shape. , Flat shape, golden flat sugar shape, and spindle shape, as well as those of various sizes, with a simple configuration, quality under mild conditions for all 100 objects. Plasma sterilization can be performed continuously and stably without deteriorating.

In the above configuration, the supply means 3 supplies the object 100 between the electrodes of the upper electrode 11 and the lower electrode 12 through the gaps in the mesh of the upper electrode 11, but the present invention is not limited to this, for example. As shown in FIG. 9, similarly to the first embodiment, the supply means 3 can directly supply the object 100 between the electrodes without passing through the mesh gap of the upper electrode 11. Is.

As shown in FIG. 9B, the control means 4 controls its inclination direction (forward direction R and reverse direction L), so that plasma sterilization is concentrated in the horizontal position fixed by the reverse direction L. At the position inclined by the forward direction R, the object 100 after sterilization is discharged.

Further, as shown in FIG. 10, a plurality of counter electrodes 1 can be arranged in series as a configuration (stacked stack type) in which the above-mentioned counter electrodes 1 are arranged in a plurality of stages and are connected to one axis 41 in a plurality of stages. is there. As shown in FIG. 10, it is also possible to accommodate the entire plasma sterilizer according to the present embodiment in a cylindrical container, and the supply means 3 can be arranged on the outer peripheral portion of each stage.

As described above, in the plasma sterilizer according to the present embodiment, the object 100 is sequentially supplied from the counter electrode 1 in the uppermost stage and sterilized in the upper stage due to the multi-stage laminated stack type configuration. The object 100 moves to the continuous lower counter electrode 11, and sterilization and discharge are repeated in the same manner, and the object 100 continuously moves between the counter electrode 1 and the storage means 2. It is possible to secure a substantial sterilization processing time and easily perform quick and efficient sterilization.

(Third Embodiment)
Hereinafter, the plasma sterilizer according to the third embodiment will be described with reference to FIG.

The third embodiment includes the counter electrode 1, the accommodating means 2, the supply means 3, and the control means 4, as in the first embodiment described above, and is further shown in FIG. As described above, a liquid liquid dielectric C is formed by being sealed with a derivative case formed of a dielectric material (for example, glass) between the counter electrode 1 composed of the upper electrode 11 and the lower electrode 12. It is configured to include the discharge position control unit 5 to be generated.

The liquid constituting the liquid dielectric C is not particularly limited, but it is preferable to use a polarizing liquid such as water, nitrobenzene, methyl alcohol, or acetone from the viewpoint of good temperature-dependent characteristics of the solvent dielectric constant. In particular, it is more preferable to use water because it is easy to handle.

Further, the liquid liquid dielectric C is preferably filled in the derivative case without gaps from the viewpoint of more efficiently obtaining the effect of suppressing the generation of arc discharge described later.

In this way, due to the action of the discharge position control unit 5, the dielectric constant decreases at the position where plasma is generated between the counter electrodes 1, and the next plasma generation position sequentially shifts to another adjacent position having a high dielectric constant. As a result, the generation of arc discharge is suppressed, and stable and gentle discharge is continuously generated between the counter electrodes 1 (between the upper electrode 11 and the lower electrode 12), which damages the object 100. Plasma sterilization can be maintained in a gentle discharge state that does not give.

That is, by the configuration including the discharge position control unit 5, plasma generation can be made uniform even in a non-uniform electric field distribution in which an object 100 treated as a foreign substance from the viewpoint of discharge exists between the electrodes. It can be stabilized.

The discharge position control unit 5 configured in this embodiment can also be applied to the plasma sterilizer according to the first and second embodiments.

1 Opposite electrode 11 Upper electrode 11a Upper mesh electrode 12 Lower electrode 12a Lower mesh electrode 2 Storage means 21 Bottom surface 22 Partition body 22a Guide fin 22b Frame body 22c Outlet 23 Storage 3 Supply means 4 Control means 41 Axis 5 Discharge position Control unit 100 Object 200 AC power supply 200a Upper AC power supply 200b Lower AC power supply 200c Central power supply 300 Recovery unit

Claims (5)

In a plasma sterilizer that sterilizes an object by plasma generated by applying a voltage between electrodes in a raw material gas atmosphere.
A counter electrode consisting of a plate-shaped upper electrode and a lower electrode facing each other with a gap in the vertical direction,
The bottom surface is formed of a plate-shaped insulating material or the lower electrode, and is composed of a storage portion provided with a partition wall on the outer periphery. The storage portion is arranged between the counter electrodes, and an object is stored in the storage portion. The storage means that is pivotally supported in the state of being
A supply means for supplying the object toward the gap, and
A control means for controlling the retention and discharge of the object in the storage means by changing the axis supporting the storage means.
A plasma sterilizer characterized by being equipped with. In the plasma sterilizer according to claim 1,
The storage means includes guide fins radially placed as the partition wall.
The accommodating means swings with respect to the counter electrode and
A plasma sterilizer in which the control means changes the axis to control the traveling direction of the swing. In the plasma sterilizer according to claim 1,
The storage means includes a frame body portion arranged at the outer end portion of the insulating material as the partition wall body, and an opening-shaped discharge port in a part of the frame body portion.
A plasma sterilizer, wherein the control means changes the axis to control an inclination angle of the storage means. In the plasma sterilizer according to any one of claims 1 to 3.
A plasma sterilizer in which the supply means supplies the raw material gas together with the object. In the plasma sterilizer according to any one of claims 1 to 4.
A plasma sterilizer comprising a discharge position control unit formed by sealing a liquid dielectric between the counter electrodes.

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