JP4838364B2 - Steam plasma generator and sterilizer - Google Patents

Description

  The present invention includes, for example, a water vapor plasma generation apparatus that generates a water vapor plasma for sterilizing or sterilizing microorganisms, pests, and the like present in an object to be processed such as food, food, feed, and pharmaceuticals, and a sterilization / sterilization water vapor plasma generation apparatus. It relates to sterilization equipment.

  As an example of a sterilization / sterilization apparatus for food or the like, for example, as shown in Patent Document 1, one using heated steam is known. Specifically, jet water is introduced from one of the cylindrical bodies filled with the heated body composed of a plurality of spheres, and the heated body is induction-induced through an excitation coil wound around the outer circumference of the cylindrical body. By heating, heating steam is ejected from the other side of the cylindrical body. An apparatus for sterilizing and sterilizing by injecting this heated steam onto food or the like is described.

International Publication No. 2004/068033 Pamphlet

  However, in the above-described sterilization / sterilization apparatus using heated steam, sufficient sterilization and sterilization effects may not be obtained because the temperature of the heated steam is unstable. In addition, in order to forcibly obtain a sterilizing / sterilizing effect, when a high-temperature heating steam is sprayed on an object to be processed such as food over time, there is a problem that nutritional components such as food are denatured and decomposed. .

  The present invention has been made in view of the above circumstances, and can sterilize and sterilize a large amount of workpieces in a short time, and can generate water vapor plasma excellent in sterilization and sterilization ability. It is an object of the present invention to provide a water vapor plasma generation apparatus and a sterilization / sterilization apparatus including the sterilization / sterilization water vapor plasma generation apparatus.

  The present inventors have repeated research to obtain a stable plasma generation apparatus, and found that a water vapor plasma can be stably generated by an apparatus including a plurality of heated members having a specific configuration, thereby completing the present invention. I let you.

That is, the present invention is as follows.
Water vapor plasma comprising: a heated body that flows out the flowing water vapor as water vapor plasma, and has conductivity; and a coil that is wound around the heated body and that is supplied with a high frequency and electromagnetically heats the heated body. A generating device,
The heated body is composed of a plurality of heated members integrally connected from the water vapor inflow side to the water vapor plasma outflow side,
The plurality of heated members include a through-hole whose number is gradually reduced from the inflow side of the water vapor to the outflow side of the water vapor plasma, and the water vapor together with the through hole on at least one of the surfaces facing each other. And a recess that constitutes the passband of
The coil has a hollow tube at the center of its linear body, and the hollow tube is a water vapor plasma generator, which is a flow path through which a coolant flows.

  Moreover, this invention is a preferable aspect that the said to-be-heated member is on a disk.

  Moreover, this invention is a preferable aspect that the recessed part of the said to-be-heated member is a groove | channel.

  Moreover, this invention is a preferable aspect that the temperature of the said outflowing water vapor plasma is 250 degreeC or more.

  Moreover, this invention is a preferable aspect that the output of the said high frequency is 30 kW or more.

According to the present invention, there is provided a water vapor plasma generating apparatus for sterilization / sterilization capable of generating a water vapor plasma excellent in sterilization / sterilization ability, capable of sterilizing / sterilizing a large amount of objects to be processed in a short time and at a stable high temperature. The sterilization / sterilization apparatus provided with this sterilization / sterilization water vapor plasma generator can be provided.
According to the present invention, water vapor plasma can be generated stably. By irradiating water vapor plasma to an object to be processed such as food, it is possible to easily sterilize and destroy nutrients in food. Sterilization can be performed. As a result, the state of preservation of foods and the like in a high temperature and high humidity region can be kept good.

It is a schematic explanatory drawing showing the whole structure of the sterilization and sterilization apparatus which concerns on embodiment of this invention. (A) is a side view of an example of a heated disk member positioned at the extreme end on the side where water vapor flows from the steam boiler, and (B) is a front view of the heated disk member shown in FIG. It is. (A) is a side view of an example of a heated disk member located at the extreme end on the side from which water vapor plasma flows out, and (B) is a front view of the heated disk member shown in FIG. 3 (A). . It is an example of the sterilization and sterilization processing apparatus (sterilization and sterilization processing room) in the case of processing a liquid.

  The water vapor plasma generator of the present invention includes a heated object and a coil for electromagnetically heating the heated object. The water vapor that has flowed into the heated body is heated in the heated body, becomes ionized, and flows out as water vapor plasma.

  The heated object for heating water vapor is wound around a coil for electromagnetic induction heating. The heated object is heated by electromagnetic induction by supplying high frequency to the coil. Since the member to be heated is heated by electromagnetic induction, it needs to be a member having conductivity. Moreover, although mentioned later, it is preferable that the water vapor plasma of this invention is 250 to 850 degreeC. For this reason, the member to be heated is preferably made of a material having stability even at a temperature of 850 ° C. Specific examples include iron, stainless steel, and copper. The flowing water vapor is heated by the heated body, but is preferably heated to 250 ° C. or higher. This is because the water vapor plasma is stably generated when the temperature is 250 ° C. or higher. At this time, the high-frequency output is preferably 30 kW or more. This is because water vapor plasma can be generated stably.

  The member to be heated is composed of a plurality of members to be heated integrally connected from the water vapor inflow side to the water vapor plasma outflow side. In addition, the plurality of heated members include a through-hole whose number is gradually reduced from the inflow side of the water vapor to the outflow side of the water vapor plasma, and the through hole on at least one of the surfaces facing each other. A recess that forms a water vapor passage area is formed.

By having such a configuration, the water vapor that has flowed into the heated body is heated by the electromagnetic induction heated heated body, and the number of through holes and water vapor that gradually decreases toward the outflow side. It passes through the recesses that make up the zone. At this time, since the heated member is gradually restricted in the passage area toward the outflow side, the steam gradually expands while colliding with the heated disk member, and the force passing through the through hole gradually increases. As a result, it becomes ionized and flows out as water vapor plasma.

  In order to stabilize the temperature of the fluid passing through the heated body and to prevent the coil itself from generating heat, the coil wound around the heated body has a hollow tube at the center of the wire. It is necessary to flow a coolant through the hollow tube. The type of the coolant is not particularly limited, but it is preferable from the viewpoint of cost to use water. The temperature of the coolant is not particularly limited, but when cooling water is used, it may be about 10 to 40 ° C. close to normal temperature.

  A plasma generation apparatus according to an embodiment of the present invention will be described below with reference to the drawings.

  The sterilization / sterilization apparatus 1 is a water vapor generated by the water vapor plasma generator 10 to generate microorganisms such as general living bacteria, coliform bacteria, and spore bacteria, pests, etc. present on the surface of the object to be processed such as food, food, data, and pharmaceuticals. It is a device that sterilizes and sterilizes with plasma.

  As shown in FIG. 1, the sterilization / sterilization apparatus 1 includes a water vapor plasma generation apparatus 10, a sterilization / sterilization treatment chamber 20, an inverter 30, a steam boiler 40, and a coolant tank 50.

  The water vapor plasma generation apparatus 10 is an apparatus that generates water vapor plasma that irradiates an object to be processed such as food. The water vapor plasma generator 10 includes a heated body 11, a coil 12 for electromagnetically heating the heated body 11, a heat insulating material 13 that covers and heats the heated body 11, and a steam boiler 40 on the heated body 11. In order to inject the water vapor plasma 71 into the sterilization / sterilization treatment chamber 20, the water vapor plasma outflow portion 71 for flowing out the water vapor plasma generated from the heated object 11, and the water vapor plasma into the sterilization / sterilization treatment chamber 20. The injection nozzle 73 is provided. The water vapor plasma generator 10 is protected by a plastic insulating cover (not shown).

  The heated object 11 is heated by electromagnetic induction by the coil 12 to which the high frequency current from the inverter 30 is supplied. The heated body 11 is preferably composed of a plurality of heated disk members 11a having conductivity. The object to be heated is not necessarily a disk member, but a disk shape is preferable in view of the efficiency of electromagnetic induction heating of the object to be heated by a coil. For the heated disk member 11a, a conductive material is used, for example, a metal such as iron, stainless steel, nickel, titanium, or a conductive ceramic material such as carbon ceramic.

  As shown in FIG. 1, the plurality of heated disk members 11 a are integrally connected from the steam boiler 40 side to the steam plasma flow side to the steam plasma flow side. Further, as shown in FIGS. 2 and 3, the heated disk member 11a is formed with a plurality of through holes 111a, and a plurality of grooves 112a are formed on the front and back surfaces of the heated disk member 11a. . FIG. 2 shows a heated disk member 11a positioned at the extreme end on the side where water vapor flows from the steam boiler 40, and FIG. 3 shows a heated disk member 11a positioned at the extreme end on the side where water vapor plasma flows out. Show.

The through-holes 111a formed in the heated disk member 11a are formed so that the number thereof gradually decreases from the steam boiler 40 flowing side toward the water vapor plasma flowing side. As an example, the number of through-holes 111a formed in the heated disk member 11a disposed at the extreme end on the side where water vapor flows from the steam boiler 40 is, for example, 100, one on the side where water vapor plasma flows out. The number of through holes 111a formed in the heated disk member 11a disposed at the end is, for example, ten. There is no particular limitation on the number of members to be heated integrally provided, and the number is determined according to the output of the high frequency, the frequency, the type and amount of the object to be processed, and the like.

  Since the groove 112a of the heated disk member 11a is irregularly formed, a space 113a (FIG. 1) is formed between the plurality of heated disk members 11a. The range in which water vapor that has flowed into the heated body 11 can pass only into the space 113a and the through-hole 111a is limited, and the number of through-holes 111a decreases toward the side that flows out as water vapor plasma, so that it can pass through. The range is gradually limited.

  The water vapor flowing into the heated body 11 is heated to a temperature of 250 ° C. or higher by the heated body 11 heated by electromagnetic induction, and gradually decreases in number toward the outflow side and in the space 113a. Passing through only, the passage area is gradually limited toward the outflow side. For this reason, the water vapor gradually expands while colliding with the heated disk member 11a, and the force passing through the through hole 111a gradually increases. As a result, the water vapor becomes ionized and flows out as water vapor plasma. In addition, although the passage area is gradually restricted toward the outflow side, the inflowing water vapor does not flow backward. Moreover, although the water vapor | steam which flowed into the to-be-heated body 11 is electromagnetic induction heating, when the water vapor | steam heated is lower than 250 degreeC, it exists in the tendency for water vapor | steam plasma not to be produced | generated stably.

  In the outflowed water vapor plasma, positive and negative charged particles fly at a high speed, and a large Coulomb force works between the charged particles, so that the particles have more than electric neutral gas such as superheated steam. Kinetic energy is much higher. The water vapor plasma is high due to the presence of highly active neutral atoms and molecules such as hydrogen atoms, oxygen atoms, and OH radicals in the water vapor that are disconnected by the high energy particles. Has sterilization and sterilization power.

  To manufacture the object to be heated 11, first, through holes 111a and grooves 112a are formed in a plurality of square plates. Then, each square plate is joined by welding. A plurality of joined square plates can be used as they are to be heated as they are to be heated, and can also be made to be heated by forming them into a disk shape with a lathe.

  The coil 12 has a hollow tube at the center of the wire body, and prevents the coil 12 itself from generating heat by flowing a cooling liquid from the inflow hose 51 to the hollow tube, and the fluid that passes through the heated body 11. The temperature can be stabilized. If the coolant is not supplied to the coil 12, the temperature of the fluid passing through the heated object 11 becomes unstable, and water vapor plasma cannot be generated.

The inverter 30 is a device that applies high-frequency induction heating to the heated object 11 via the coil 12. The inverter 30 is a high-frequency inverter, and the high-frequency output is preferably about 30 to 500 kW, and the frequency is preferably 10 to 20 kHz. Note that the inverter 30 is electrically connected to the coil 12 by a conductive wire 31.
When the high frequency output is 30 kW or more, the water vapor plasma generation apparatus 10 can stably generate the water vapor plasma. An inflow hose 51 for cooling liquid from the cooling water tank 50 also passes through the inverter 30 to remove heat from the semiconductor elements and the like disposed inside.

  The steam boiler 40 is connected to the water vapor plasma generation apparatus 10 via a water vapor inflow portion 71 by a conduit 60. The conduit 60 is provided with an on-off valve 61 and a check valve 62 for steam generated by the steam boiler 40.

  The coolant tank 50 allows the coolant to flow into one end of the wire body of the coil 12 and also removes the inside of the inverter 30 from the inflow hose 51 and causes the coolant to flow out from the other end of the wire body of the coil 12. And an outflow hose 52.

  The sterilization / sterilization chamber 20 includes a cylindrical main body 21, a workpiece input port 22 disposed above the main body, a workpiece input adjusting unit 23, and water vapor plasma irradiation formed on the side wall of the main body 21. An opening 24 and an installation base 25 that supports the main body 21 are provided. A water vapor plasma introduction tube 74 is connected to the water vapor plasma irradiation opening 24. Since the main body 21 is formed in a cylindrical shape, the atmosphere does not flow from the upper workpiece input port 22, the inside of the main body 21 is in a vacuum state, the temperature of the irradiated water vapor plasma is stabilized, and Improves sterilization and sterilization effect of processed products. The vacuum state means a state where the pressure is lower than the atmospheric pressure.

  The temperature of the water vapor plasma in the main body 21 is a stable temperature between 250 ° C. and 850 ° C. The temperature of the water vapor plasma can be appropriately set according to the type of the object to be processed.

  In a state where the water vapor plasma injected from the injection nozzle 73 of the water vapor plasma generation apparatus 10 is injected from the water vapor plasma irradiation opening 24 via the water vapor plasma introduction pipe 74, the object to be processed is supplied from the object input port 22. When charged, water vapor plasma is irradiated to the workpiece. Thereby, plasma irradiation processing is performed.

  The design of the sterilization / sterilization chamber 20 can be changed as appropriate according to the type of the object to be processed. In FIG. 1, the workpiece is introduced from above the processing chamber, and the water vapor plasma is instantaneously irradiated while dropping due to gravity. However, the processing chamber is designed to be long in the horizontal direction, By using it, it is possible to design it so that plasma can be irradiated for a relatively long time.

Further, when sterilizing / sterilizing a liquid, it is preferable to use the sterilization / sterilization treatment chamber shown in FIG. The main body 21 uses a cylindrical member, and allows the liquid to flow from the workpiece input port 22 toward the outlet with an inclination of about 10 to 40 degrees, preferably 15 to 30 degrees. At this time, the liquid can be sterilized and sterilized by connecting the water vapor plasma introduction pipe 74 to the main body 21 and injecting the water vapor plasma into the liquid in a portion of the main body 21 close to the workpiece input port. The cylinder may not be a perfect circle in cross section, and may be an ellipse or a semicircle, for example. Further, the liquid injected into the main body preferably has a liquid filling rate of 50% or less, more preferably 30% or less, in order to enhance the effect of sterilization and sterilization by plasma. More preferably, it is 20% or less. By installing a liquid tray at the outlet of the main body 21, the sterilized and sterilized liquid is collected. As the tray, a tank having an appropriate size can be used according to the amount of liquid to be charged.
The liquid that can be treated in the sterilization / sterilization treatment chamber shown in FIG. 4 is not particularly limited, and examples thereof include water, beverages such as juice, processed foods such as soup, and oily substances such as vegetable oil and animal oil.

  As described above, in the water vapor plasma generation apparatus of the present embodiment, the structure of the heated object 11 is configured such that the passage region of the flowed water vapor is gradually limited toward the outflow side, and the wire body of the coil 12 is By supplying a coolant and stabilizing the temperature of the water vapor passing through the heated object 11, high-frequency inverter 30 can supply high frequency. As a result, stable water vapor plasma can be generated.

In the sterilization / sterilization apparatus according to the present embodiment, the water vapor plasma generated by the water vapor plasma generation apparatus 10 is injected into the main body 21 of the cylindrical sterilization / sterilization treatment chamber 20 in which the inflow of air is prevented, and the object to be processed is charged. Since an object to be processed such as food dropped from the mouth 22 is dropped, a large amount of object to be processed can be sterilized and sterilized in a short time (instantaneous) by a stable high-temperature steam plasma.

  While the present invention has been described with reference to the embodiment, the present invention is not limited to the above embodiment, and various modifications can be made. For example, in the present embodiment, an example in which the heated object 11 is configured by the heated disk member 11a has been described. However, as long as the fluid passage area is gradually narrowed from the inflow side to the outflow side, For example, the member to be heated may be in the shape of a square, a sphere, an indeterminate block, or the like. The number of non-heated disk members 11a is determined according to the output of the high frequency, the frequency, the type and amount of the non-processed object, and the like.

  In the present embodiment, the example in which the number of through-holes 111a formed in the heated disk member 11a is gradually reduced from 100 to 10 toward the outflow side has been described. The method of reducing the sheath is determined according to the number and size of the heated disk member 11a itself, the output of the high frequency, the frequency, the type and amount of the object to be processed, and the like.

  Further, in the present embodiment, the example in which the groove 112a is formed in the heated disk member 11a to form the space 113a has been described. However, any concave portion that can form the space 113a may be used. It is also possible to form a heated disk member to form.

  Further, in the present embodiment, the example in which the grooves 112a are formed on both surfaces of the heated disk member 11a has been described. However, the heated disk members 11a may be formed only on one of the opposed surfaces. Further, depending on the position where the heated disk member 11a is disposed, there is a case where the groove 112a is not formed.

  Further, in the present embodiment, an example in which the steam boiler 40 is used to generate water vapor that flows into the heated object 11 has been described. However, any device that generates water vapor may be used. For example, water is stored in a tank. The water flowing out may be heated electrically to generate water vapor.

  By irradiating the food or the like with the water vapor plasma generated by the water vapor plasma generator, the food or the like can be sterilized. As described above, the configuration of the processing chamber 20 can be appropriately changed depending on the type of the object to be processed. For example, when a drop type such as the processing chamber 20 is used, the time during which the object to be processed is irradiated with the water vapor plasma is short, and thus it is particularly suitable for sterilization / sterilization processing of foods with small grains such as wheat.

  On the other hand, when used for sterilization and sterilization of foods to which highly resistant bacteria such as spore bacteria detected from soybeans are attached, or for roasting coffee beans, nuts and seeds, for example, a belt conveyor It is preferable to use a processing chamber having a configuration such as a type.

  When sterilization and sterilization are performed by irradiating the object to be processed with the water vapor plasma of the present invention, sterilization and sterilization is performed in a very short time. For example, when the object to be processed is a food such as wheat, protein It can be sterilized and sterilized without denaturing or degrading nutrients such as vitamins and minerals. In the present invention, the object to be treated is not particularly limited, but in particular, in the case of food, it can be applied to various foods such as soybeans, wheat, red beans, coffee, and noodles. Further, the present invention can be similarly applied to feed for livestock and agricultural products, such as waste food.

Irradiation with water vapor plasma can sterilize and sterilize microorganisms such as general live bacteria, coliform bacteria, Escherichia coli, and spore bacteria present on the surface of the object to be treated, especially in high-temperature and high-humidity conditions where bacteria can easily propagate. Very useful for food preservation. Moreover, in the sterilization / sterilization method using the water vapor plasma of the present invention, the sterilization / sterilization effect is produced by irradiating the object to be processed within 30 seconds. Depending on the type of the object to be processed, the effect can be exhibited even by irradiation for a shorter time, and the irradiation time can be appropriately set according to the type of the object to be processed.

  Hereinafter, the present invention will be described in more detail with reference to examples, but it goes without saying that the present invention is not limited to such examples.

  The sterilization / sterilization treatment chamber of the water vapor plasma generator shown in FIG. 1 was used as a drop type, the high frequency output was 30 kW, the frequency was 20 kHz, wheat was introduced into the sterilization / sterilization treatment chamber, and water vapor plasma was irradiated. The presence of bacteria before and after irradiation with water vapor plasma was confirmed. As a comparative example, sterilization and sterilization treatment using heating steam, which has been conventionally used, was performed. The results are shown in Table 1.

  As shown in Table 1, when using water vapor plasma, it can be understood that the number of general viable bacteria and the coliform group are significantly reduced as compared with the case where heated steam is used.

  The water vapor plasma generated by the water vapor plasma generator of the present invention has a sterilization / sterilization action. By the sterilization / sterilization method of the present invention, sterilization / sterilization can be performed by a simple method without destroying the ingredients of the food. In addition, for foods that are difficult to store for a long time due to the presence of microorganisms and products that have a limited expiration date due to the progress of oxidation, the shelf life and the expiration date for consumption will be significantly increased, which is useful for industry. The nature is extremely large.

DESCRIPTION OF SYMBOLS 1 Sterilization / sterilization apparatus 10 Water vapor generation apparatus 11 Heated object 11a Heated disk member 12 Coil 13 Heat insulating material 20 Sterilization / sterilization processing chamber 21 Processing chamber main body 22 Processed object inlet 23 Processed object input adjustment part 24 Water vapor plasma Irradiation opening 25 Installation base 30 Inverter 31 Conductor wire 40 Steam boiler 50 Cooling water tank 51 Inflow hose 52 Outflow hose 60 Conduit 61 On-off valve 62 Check valve 71 Steam inflow part 72 Steam plasma discharge part 73 Injection nozzle 74 Steam plasma introduction pipe 111a Through hole 112a Groove 113a Space

Claims (6)

Water vapor plasma comprising: a heated body that flows out the flowing water vapor as water vapor plasma, and has conductivity; and a coil that is wound around the heated body and that is supplied with a high frequency and electromagnetically heats the heated body. A generating device,
The heated body is composed of a plurality of heated members integrally connected from the water vapor inflow side to the water vapor plasma outflow side,
The plurality of heated members include a through-hole whose number is gradually reduced from the inflow side of the water vapor to the outflow side of the water vapor plasma, and the water vapor together with the through hole on at least one of the surfaces facing each other. And a recess that constitutes the passband of
The said coil has a hollow tube in the center of the linear body, The said hollow tube is a water vapor | steam plasma generation apparatus which is a flow path through which a cooling fluid flows.   The water vapor plasma generation apparatus according to claim 1, wherein the member to be heated has a disk shape.   The water vapor plasma generation apparatus according to claim 1, wherein the concave portion of the member to be heated is a groove.   4. The water vapor plasma generation apparatus according to claim 1, wherein a temperature of the water vapor plasma flowing out is 250 ° C. or more. 5.   The water vapor plasma generation apparatus according to any one of claims 1 to 4, wherein the high-frequency output is 30 kW or more. Water vapor plasma comprising: a heated body that flows out the flowing water vapor as water vapor plasma, and has conductivity; and a coil that is wound around the heated body and that is supplied with a high frequency and electromagnetically heats the heated body. A sterilization / sterilization apparatus comprising a generation apparatus and a sterilization / sterilization treatment chamber for irradiating a workpiece with water vapor plasma generated by the water vapor plasma generation apparatus,
The heated body is composed of a plurality of heated members integrally connected from the water vapor inflow side to the water vapor plasma outflow side,
The plurality of heated members include a through-hole whose number is gradually reduced from the inflow side of the water vapor to the outflow side of the water vapor plasma, and the water vapor together with the through hole on at least one of the surfaces facing each other. And a recess that constitutes the passband of
The coil has a hollow tube at the center of the wire, and the hollow tube is a flow path through which a coolant flows.
The sterilization / sterilization chamber includes a cylindrical main body having an opening formed on a side wall for irradiating the processed water vapor plasma to the processing object, and a processing object inlet disposed above the main body. A sterilization / sterilization apparatus comprising:

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