JP7106089B2 - Microbubble sterilization system and method for sterilizing seafood, beverages and foods - Google Patents

Description

TECHNICAL FIELD The present invention relates to a sterilization system using ultrasonic waves to crush microbubbles, and a method for sterilizing seafood, beverages, and foods using ultrasonic waves to crush microbubbles.

Conventionally, liquids containing ultra-fine bubbles are expected to have bactericidal effects, cleansing effects, growth-promoting effects of organisms, and the like. As a method for producing a liquid containing ultra-fine bubbles, in addition to a swirling flow method, a pressurized dissolution method, a micropore method, etc., an ultrasonic method in which fine bubbles are converted into ultra-fine bubbles by ultrasonic shock waves is known. .

For example, in the nanobubble generating device described in Prior Art Document 1, a liquid containing fine bubbles is stored in a storage section, and ultrasonic waves are applied to the storage section to convert the microbubbles into nanobubbles, whereby the ultrafine bubble-containing liquid is manufactured.

The ultra-fine bubble-containing liquid generated by this nanobubble generator is temporarily stored in a storage section, and then taken out from the storage section as needed and applied to an object. In Prior Art Document 1, for example, it is reported that disease damage and mold damage were suppressed by applying (dispersing) grapes in a vineyard as an object to be sterilized.

JP 2017-47419 A

However, in anticipation of the sterilization effect of the ultra-fine bubbles themselves of the ultra-fine bubble-containing liquid, even if the ultra-fine bubble-containing liquid generated by the generation device is applied to the object to be sterilized, the expected sterilization effect cannot be obtained. Sometimes I couldn't. For example, bacteria, viruses, bacteria, etc. accumulated inside fish and shellfish cannot be sufficiently sterilized, and a clear sterilization effect on beverages has not been proven.

That is, the mechanism of sterilization by ultra-fine bubble-containing liquids has not been elucidated, and the sterilization effect of ultra-fine bubbles itself is often limited. Furthermore, the adsorption/desorption action of ultra-fine bubbles and the sterilization action using ultrasonic crushing energy when generating ultra-fine bubbles by ultrasonic crushing have not been known.

The present invention has been made in view of such problems, and by using ultrasonic waves for generating ultrafine bubbles for sterilization, it is possible to efficiently sterilize an object to be sterilized.

(1) A first microbubble sterilization system according to the present invention includes a microbubble generating unit that generates microbubbles in a liquid, a storage unit that stores the liquid, and the microbubble generating unit and the storage unit. a passageway; and an ultrasonic irradiation unit provided in the passageway for irradiating the liquid containing the microbubbles and passing through the passageway with ultrasonic waves to crush the microbubbles to generate ultrafine bubbles, A microbubble sterilization system in which a circulation path for circulating the liquid is formed by the reservoir, the microbubble generator, and the passage, wherein the reservoir is introduced with an object to be sterilized. .

According to this microbubble sterilization system, the liquid passing through the passage connecting the reservoir and the microbubble generator is irradiated with ultrasonic waves from the ultrasonic wave irradiation section. In addition, the object to be sterilized is introduced into the storage section that stores the liquid containing the ultrafine bubbles, and the liquid stored in the storage section is returned to the microbubble generation section through the circulation path.

Since there are no obstacles such as objects to be sterilized in the passage where ultrasonic waves are irradiated, a strong ultrasonic crushing field is formed in the passage, effectively crushing fine bubbles in the liquid, Can generate bubbles. Then, a liquid containing microbubbles and ultrafine bubbles is supplied to the reservoir.

Viruses, bacteria, etc., are desorbed from the object to be sterilized introduced into the storage unit to which the liquid is supplied, and the liquid containing the desorbed viruses, bacteria, etc. and passes through a passageway that is irradiated with ultrasound. A strong ultrasonic crushing field is formed in the passageway, crushing microbubbles to generate ultrafine bubbles, and efficiently sterilizing viruses, bacteria, etc. in the liquid by ultrasonic crushing energy.

Therefore, in this microbubble sterilization system, viruses and bacteria accumulated in the object to be sterilized are adsorbed and desorbed, and when the liquid containing the desorbed virus circulates through the circulation path and passes through the passage, ultrasonic waves are generated. Therefore, it is possible to efficiently sterilize viruses, bacteria, etc. that have accumulated or adhered to the object to be sterilized, which has been difficult to sterilize in the past.

(2) The second microbubble sterilization system according to the present invention includes a microbubble generation unit that generates microbubbles in a liquid, and a microbubble generation unit that is connected to the microbubble generation unit and contains microbubbles from the microbubble generation unit. a reservoir for storing a liquid introduced therein; and a superfine bubble provided in the reservoir for irradiating the liquid containing the microbubbles and introduced into the reservoir with ultrasonic waves to crush the microbubbles. and an ultrasonic irradiation unit that generates a microbubble sterilization system, wherein an object to be sterilized is introduced into the storage unit.

According to this microbubble sterilization system, the storage section is irradiated with ultrasonic waves from the ultrasonic wave irradiation section. In addition, the object to be sterilized is introduced into the storage section that stores the liquid containing the ultrafine bubbles. As a result, viruses, bacteria, etc., are adsorbed and desorbed from the object to be sterilized introduced into the reservoir, and the desorbed virus, bacteria, etc. directly sterilized by

Therefore, ultrafine bubbles can be generated and efficient sterilization can be performed by ultrasonic crushing energy, so viruses and bacteria attached to the object to be sterilized, which were difficult to sterilize in the past, can be efficiently removed. can do.

(3) A third microbubble sterilization system according to the present invention includes a microbubble generation unit that generates microbubbles in a liquid, a storage unit that stores the liquid, and intervenes between the microbubble generation unit and the storage unit. a passageway; and a first ultrasonic wave irradiation unit provided in the passageway for irradiating the liquid containing the microbubbles and passing through the passageway with ultrasonic waves to crush the microbubbles to generate ultrafine bubbles. a second ultrasonic irradiation unit provided in the reservoir for irradiating the liquid containing the microbubbles and introduced into the reservoir with ultrasonic waves to crush the microbubbles to generate ultrafine bubbles; and forming a circulation path for circulating the liquid by the reservoir, the microbubble generator, and the passage, wherein the reservoir is introduced with an object to be sterilized. It is characterized by

According to this microbubble sterilization system, the liquid passing through the passage connecting the storage section and the microbubble generation section is irradiated with ultrasonic waves from the ultrasonic wave irradiation section, and the storage section is also irradiated with ultrasonic waves from the ultrasonic wave irradiation section. be. In addition, the object to be sterilized is introduced into the storage section that stores the liquid containing the ultrafine bubbles, and the liquid stored in the storage section is returned to the microbubble generation section through the circulation path.

Since there are no obstacles such as objects to be sterilized in the passage where ultrasonic waves are irradiated, a powerful ultrasonic crushing field is formed in the passage, effectively crushing fine bubbles in the liquid into ultra-fine bubbles. can. Then, the liquid can be circulated while generating ultrafine bubbles, and the object to be sterilized can be introduced into the reservoir that stores the liquid containing the ultrafine bubbles and sterilized. As a result, ultrafine bubbles can be efficiently generated in the passage irradiated with ultrasonic waves, and efficient sterilization can be performed by ultrasonic crushing energy.

In addition, viruses, bacteria, etc., are detached from the object to be sterilized introduced into the reservoir by ultrafine bubbles, and the desorbed virus, bacteria, etc. are directly emitted by ultrasonic waves irradiated to the reservoir. Sterilized. As a result, in the reservoir, ultrafine bubbles can be efficiently generated, and efficient sterilization can be performed by ultrasonic crushing energy. and bacteria can be efficiently sterilized.

In other words, viruses, bacteria, etc. are detached from the object to be sterilized introduced into the storage part by ultrafine bubbles, and while the liquid containing the desorbed viruses, bacteria, etc. circulates in the system, the passage and the storage part Ultrasonic waves are irradiated from the ultrasonic wave irradiation unit to crush the microbubbles to generate ultrafine bubbles, and viruses, bacteria, etc. in the liquid are sterilized by the ultrasonic crushing energy. As a result, it is possible to efficiently remove viruses, bacteria, etc. adhering to the object to be sterilized, which has conventionally been difficult to sterilize.

(4) The liquid and the object to be sterilized may be beverages. By doing so, the beverage can be directly sterilized by ultrasonic waves, so that effective sterilization can be performed without heating.

(5) In the microbubble sterilization system described above, the reservoir includes a reservoir that stores the liquid and a holding member that holds the object to be sterilized, and the microbubbles or ultrafine bubbles are Viruses or bacteria may be detached from the object to be sterilized.

According to such a microbubble sterilization system, the position of the object to be sterilized in the reservoir can be adjusted by arranging the holding member that holds the object to be sterilized in the reservoir of the reservoir. Thereby, for example, when forming the ultrasonically crushing portion in the reservoir, the object to be sterilized can be held in the ultrasonically crushing field, or the object to be sterilized can be held at a position different from the ultrasonically crushing field. can be done.

If the object to be sterilized is held in the vicinity of the ultrasonic crushing field, the object to be sterilized directly receives ultrasonic waves and is directly sterilized, thereby improving the sterilization efficiency. On the other hand, if the object to be sterilized is held at a position away from the ultrasonic crushing field, the object to be sterilized does not become an obstacle to the transmission of ultrasonic waves, and the crushing field is efficiently formed. Improves bubble generation efficiency.

In addition, since ultrafine bubbles tend to cluster downward as the particle size decreases, by holding the object to be sterilized at a position where the ultrafine bubbles of the desired particle size are concentrated, Viruses and bacteria can be selectively desorbed and sterilized efficiently.

(6) The storage unit includes a storage tank for storing the liquid, and the storage tank includes a bottom and an outlet formed substantially in the center of the bottom for discharging the liquid stored in the storage tank. and a side peripheral portion on which a plurality of the ultrasonic irradiation units are attached and which continues upward from the bottom portion, and the storage tank is arranged to extend to the bottom portion centering on the discharge port by discharging the liquid from the outlet port. A vortex that rotates toward the target is formed, and the plurality of ultrasonic wave irradiation units irradiate ultrasonic waves toward the center of the vortex, and the microbubbles or ultrafine bubbles desorb viruses or bacteria from the object to be sterilized. good too.

In such a microbubble sterilization system, an ultrasonic collapsing field is formed in the center of the vortex formed in the reservoir of the reservoir. As a result, high-concentration ultra-fine bubbles are generated from the fine bubbles in the center of the storage tank, and spread to the surroundings in a whirlpool. As a result, the microbubbles and ultrafine bubbles can effectively circulate throughout the reservoir and contact the object to be sterilized introduced into the reservoir. Therefore, fine bubbles and ultrafine bubbles, particularly ultrafine bubbles having a particle size of 100 μm or less, can be effectively acted on the object to be sterilized introduced into the storage tank.

(7) The storage tank may further include an opening serving as an upper end of the side peripheral portion, and the liquid may be introduced in the circumferential direction from the periphery of the opening.

In such a microbubble sterilization system, by introducing liquid in the circumferential direction from the opening at the upper end of the side circumference, the vortex formed in the storage tank spreads to the side circumference and collapses at the center of the vortex. The ultrafine bubbles generated by can effectively diffuse into the reservoir.

(8) A fourth microbubble sterilization system according to the present invention includes introducing an object to be sterilized into a liquid, generating microbubbles in the liquid, irradiating ultrasonic waves, and ultrasonically crushing the liquid into the liquid. forming a field; crushing the microbubbles by the ultrasonic crushing field to generate ultramicrobubbles, wherein the ultrasonic crushing field crushes the microbubbles to create hydroxyl radicals in the liquid; It is characterized by sterilizing viruses or bacteria in liquid by generating, producing ultraviolet rays, and causing cavitation.

According to this microbubble sterilization system, a liquid containing microbubbles is irradiated with ultrasonic waves to form an ultrasonic crushing field, thereby crushing the microbubbles and generating ultrafine bubbles. At this time, the microbubbles are crushed to generate hydroxyl radicals, and UV light emission and cavitation are generated, which act on viruses or bacteria.

In addition, since the microbubbles and ultrafine bubbles in the liquid selectively adsorb and desorb viruses and bacteria from the object to be sterilized, the viruses or bacteria attached to or accumulated on the object to be sterilized are discharged into the liquid, Can be sterilized. As a result, it is possible to efficiently sterilize viruses, bacteria, and the like attached to or accumulated on the object to be sterilized, which has conventionally been difficult to sterilize.

(9) A method for sterilizing seafood according to the present invention includes a preparation step of preparing seawater in a reservoir, an introduction step of introducing seafood into the reservoir, and fine bubbles of oxygen gas or carbon dioxide gas in the seawater. and an ultrasonic crushing step of irradiating seawater containing the microbubbles with ultrasonic waves to crush them, and in the ultrasonic crushing step, the microbubbles are crushed by ultrasonic waves. It is characterized by generating ultrafine air bubbles and sterilizing the seawater.

According to this seafood sterilization method, the seawater prepared in the reservoir contains microbubbles and is crushed by ultrasonic waves to generate ultrafine bubbles. At this time, fish and shellfish are introduced into the reservoir where seawater is prepared, and viruses, bacteria, etc. accumulated on the surface and inside the fish and shellfish are desorbed by microbubbles and ultrafine bubbles of the seawater. This desorption selectively desorbs viruses and bacteria having a size close to the particle size of the microbubbles or ultrafine bubbles, depending on the particle size.

Then, the seawater containing detached viruses, bacteria, etc. is sterilized by being irradiated with ultrasonic waves. That is, according to this sterilization method for seafood, ultrafine bubbles that desorb viruses, bacteria, etc. can be efficiently generated, and efficient sterilization can be performed by ultrasonic crushing energy. It is possible to efficiently remove viruses, bacteria, etc. attached to the object to be sterilized, which were difficult to remove.

(10) In the preparation step, seawater containing microbubbles is prepared in the storage section in the microbubble generation step, and in the ultrasonic crushing step, seawater stored in the storage section is irradiated with ultrasonic waves. good too.

According to such a sterilization method for seafood, since the seawater in the storage part is directly irradiated with ultrasonic waves, viruses and bacteria that are desorbed and discharged into the liquid are sterilized immediately after discharge. , can prevent viruses and bacteria from accumulating again in seafood.

(11) A beverage sterilization method according to the present invention includes a preparation step of preparing a beverage in a reservoir, a microbubble generation step of causing the beverage stored in the reservoir to contain microbubbles, and containing the microbubbles. and an ultrasonic crushing step of crushing the beverage by irradiating it with ultrasonic waves, wherein the ultrasonic crushing step sterilizes the beverage.

According to this beverage sterilization method, the beverage prepared in the reservoir contains microbubbles and is crushed by ultrasonic waves to generate ultrafine bubbles. At this time, viruses, bacteria, and the like are sterilized by ultrasonic waves in the reservoir where the beverage is prepared. In addition, the ultrafine bubbles generated by ultrasonic waves have an antibacterial effect on the beverage, and the beverage is maintained in a sterilized and safe state.

(12) In the preparation step, the beverage containing microbubbles is prepared in the storage section in the microbubble generation step, and in the ultrasonic crushing step, the beverage stored in the storage section is irradiated with ultrasonic waves. may

According to such a beverage sterilization method, the beverage in the reservoir is directly irradiated with ultrasonic waves, so viruses and bacteria in the beverage are directly sterilized, so the beverage can be sterilized efficiently. can.

(13) A food sterilization method according to the present invention includes a preparation step of preparing a liquid in a reservoir, an introduction step of introducing food into the reservoir, and a microbubble containing fine bubbles of carbon dioxide gas in the beverage. and an ultrasonic crushing step of applying ultrasonic waves to the liquid containing the microbubbles to crush them. In the ultrasonic crushing step, the microbubbles are crushed by ultrasonic waves to form ultrafine bubbles. It is characterized by generating and sterilizing the liquid.

According to this food sterilization method, the position of the food in the reservoir can be adjusted by arranging the holding member that holds the object to be sterilized in the reservoir of the reservoir. As a result, for example, when the ultrasonically crushing portion is formed in the storage portion, the food can be held in the ultrasonically crushing field, or the food can be held in a position different from the ultrasonically crushing field.

By doing so, when the food is held near the ultrasonic crushing field, the food is directly subjected to ultrasonic waves and directly sterilized, thereby improving the sterilization efficiency. On the other hand, if the food is held away from the ultrasonic crushing field, the food will not interfere with the transmission of the ultrasonic waves, and the crushing field will be formed efficiently, improving the efficiency of generating ultrafine bubbles. do.

INDUSTRIAL APPLICABILITY The present invention can efficiently sterilize an object to be sterilized by using ultrasonic waves for generating ultrafine bubbles for sterilization.

1 shows a functional block diagram of a microbubble sterilization system according to a first embodiment of the present invention; FIG. The schematic of the passage crushing part in FIG. 1 is shown, FIG.2(A) is a side view of a passage crushing part, FIG.2(B) shows the front view of a passage crushing part. 1, FIG. 3(A) shows a plan view of the reservoir, and FIG. 3(B) shows a cross-sectional view taken along line 3B-3B of FIG. 3(A). Fig. 2 shows a schematic perspective view of a reservoir to illustrate the ultrasonic collapse and eddy currents that occur within the reservoir; It is a diagram showing the results of observing ultrafine bubbles using a PLL-mica substrate, FIG. 5(A) is an observation photograph, and FIG. 5(B) is a graph of the height above the white line in FIG. 5(A). . It is a diagram showing the results of observing ultrafine bubbles using a PLL-mica substrate, FIG. 6(A) is an observation photograph, and FIG. 6(B) is a graph of the height above the white line in FIG. 6(A). . It is a diagram showing the results of observing ultrafine bubbles using an APTES-mica substrate, FIG. 7(A) is an observation photograph, and FIG. 7(B) is a graph of the height above the white line in FIG. 7(A). . It is a diagram showing the results of observing ultrafine bubbles using an APTES-mica substrate, FIG. 8(A) is an observation photograph, and FIG. 8(B) is a graph of the height above the white line in FIG. 8(A). . FIG. 4 shows a functional block diagram of a microbubble sterilization system according to a second embodiment of the present invention; 9A and 9B are schematic diagrams of the storage portion, FIG. 10A is a plan view of the storage portion, and FIG. 10B is a cross-sectional view taken along line 10B-10B of FIG. FIG. 11 shows a functional block diagram of a microbubble sterilization system according to a third embodiment of the present invention; Figure 12 shows a schematic side sectional view of the reservoir in Figure 11;

[First Embodiment]

A microbubble sterilization system 100 according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 4. FIG. The microbubble sterilization system 100 uses microbubbles or ultrafine bubbles to sterilize an object to be sterilized, and in this embodiment, a system using seafood as the sterilization object will be described.

FIG. 1 shows a functional block diagram of a microbubble sterilization system 100. As shown in FIG. The microbubble sterilization system 100, as shown in FIG. a microbubble generation unit 120 for generating microbubbles in a liquid that is in contact with the microbubble generation unit 120; and a passage crushing portion 130 for generating microbubbles. The passage crushing portion 130 is connected to the storing portion 110 on the side opposite to the side connected to the microbubble generating portion 120 , and the ultrafine bubble-containing liquid that has passed through the passage crushing portion 130 is stored in the storing portion 110 .

In this embodiment, in order to promote the growth of cultured fish and shellfish, seawater is used as the liquid of the ultrafine bubble-containing liquid, and oxygen is used as the gas, but the types of the liquid and the gas can be changed as appropriate. For example, even when fish are the object to be sterilized, carbon dioxide may be applied to the gas to have an anesthetic effect (for example, see Japanese Patent Application Laid-Open No. 2014-39514). Further, for example, tap water may be used as the liquid and nitrogen may be used as the gas in food sterilization. Further, for example, beverages may be used as the liquid and carbon dioxide or nitrogen may be used as the gas.

The reservoir 110, the microbubble generator 120, and the passage crusher 130 are interconnected to form a circulation path R1 for circulating the liquid. A first pump 140 is arranged between the reservoir 110 and the microbubble generator 120 to supply liquid from the reservoir 110 to the microbubble generator 120 . A filtration section 150 is provided between the storage section 110 and the first pump 140 to filter the liquid supplied to the first pump 140 . The microbubble generator 120 is connected to the gas supply unit 160 and supplied with gas from the gas supply unit 160 .

The microbubble sterilization system 100 also includes a seawater introduction/outlet path D1 for introducing liquid from the sea area S into the storage section 110 or for discharging liquid from the storage section 110 to the sea area S. The seawater introduction/outlet path D1 includes a discharge path crushing section 170 . The discharge passage crushing unit 170 includes an introduction/discharge passage 171 and an ultrasonic irradiation unit 173, and ultrasonically crushes gas contained in passing seawater. A valve 180 is provided between the storage section 110 and the discharge passage crushing section 170 .

A second pump 190 is arranged between the discharge passage crushing section 170 and the sea area S, and by switching the discharge direction of the second pump 190, the liquid discharged from the discharge passage crushing section 170 is discharged to the sea area S. Liquid can be drained or pumped from the sea area S to the drain crush 170 . The microbubble sterilization system 100 may include at least one path of a supply section that supplies a predetermined liquid to the storage section 110 and a discharge section that discharges the predetermined liquid instead of the seawater introduction/outlet path D1.

The microbubble sterilization system 100 is centrally managed by the controller 1 . In FIG. 1, connections between the control unit 1 and each unit managed by the control unit 1 are indicated by dashed lines. The control unit 1 may control the microbubble sterilization system 100 in cooperation with an external control device or the like. Also, each part of the microbubble sterilization system 100 may be controlled by another control device or the like.

[Micro bubble generator]

The microbubble sterilization system 100 includes a conventionally well-known nozzle-type fine bubble generator as the microbubble generator 120 (see, for example, Japanese Patent No. 5002480). Such a nozzle-type fine bubble generator introduces a gas and a liquid into a stirring and mixing chamber, stirs and mixes the liquid and the gas by a loop-shaped flow, and forms a mixed fluid. The gas-liquid loop flow stirring and mixing chamber includes a liquid supply hole for supplying pressurized liquid to the gas-liquid loop flow stirring and mixing chamber, a gas inlet port for inflow of gas, and a gas-liquid loop stirring and mixing chamber. and a jet hole for jetting from the mixing chamber.

In this nozzle type fine bubble generator, the liquid supply hole is connected to the reservoir 110 via the first pump 140, and the pressurized liquid can be introduced into the stirring and mixing chamber. The gas supply hole is connected to the gas supply 160 to allow gas to be introduced into the agitation mixing chamber. The ejection hole is connected to the passage crushing portion 130 by a pipe, and injects the microbubble-containing liquid containing gas that has been agitated by the loop flow and turned into microbubbles toward the passage crushing portion 130 .

In the fine bubble generator, the particle size of the generated fine bubbles can be controlled by the pressure of the liquid supplied from the liquid supply hole, the pressure of the gas supplied from the gas supply hole, and the size of the ejection hole.

[passage collapse part]

2A and 2B are schematic diagrams of the passage crushing portion 130 shown in FIG. 1, where (A) shows a side view and (B) shows a front view. The passage crushing section 130 includes a conventionally well-known ultrafine bubble generator (see, for example, Japanese Patent No. 6123013). The passage crushing unit 130 is connected to the microbubble generating unit 120 on one side, and includes a passage 131 through which the microbubble-containing liquid produced by the microbubble generating unit 120 passes, and an exterior body 132 that covers the passage 131. , a two-layer structure having an intermediate space 130s between the passage 131 and the exterior body 132. As shown in FIG. Passage crushing portion 130 is connected to storage portion 110 on the other side, and arranged so that passage 131 extends in the horizontal direction.

A plurality of ultrasonic transducers 133 are provided in the exterior body 132 , and each ultrasonic transducer 133 functions as an ultrasonic wave irradiation unit that irradiates ultrasonic waves toward the passage 131 . An intermediate space 130 s between the passage 131 and the exterior body 132 is filled with a transmitting liquid, and the ultrasonic waves emitted from the ultrasonic transducer 133 are propagated into the passage 131 through the transmitting liquid. The fine bubbles of the bubble-containing liquid flowing inside are crushed.

The medium liquid is cooling water supplied from a cooling water supply unit (not shown) such as a chiller. It is drawn out from the provided propagating liquid outlet 135 . In the passage crushing portion 130, the intermediate space 130s is filled with the medium liquid (cooling water) and flows, and the ultrasonic wave irradiation by the ultrasonic transducer 133 is propagated to the medium liquid, and the liquid passing through the passage 131 is heated. . Here, since the propagation liquid also has the effect of cooling the passage crushing portion 130, the temperature of the bubble-containing liquid passing through the passage 131 can be adjusted by adjusting the flow rate of the propagation liquid flowing through the intermediate space 130s.

The passage 131 is formed of a pipe made of a material such as fluororesin such as PFA (polytetrafluoroethylene-perfluoroalkyl vinyl ether copolymer) or PVC (polyvinyl chloride). Thus, the passage 131 has a circular cross section and extends in a columnar shape with the same diameter, forming a uniform flow path in the flow direction of the bubble-containing liquid. The passage 131 is connected to the micro-bubble generating section 120 and the storage section 110 so as to intervene therebetween, and the micro-containing liquid supplied from the micro-bubble generating section 120 fills the interior of the passage 131 and flows into the storage section 110 . flowed towards

The exterior body 132 is made of stainless steel and is composed of a side peripheral member 136 extending in a hexagonal prism shape having a regular hexagonal cross section and a pair of disk-shaped planar members 137 sandwiching the side peripheral member 136 from both sides in the extending direction. . Both plane members 137 have the passage 131 fitted in the center of the plane, and the passage 131 is fixed so that the passage 131 extends on the central axis of the regular hexagonal column formed by the side circumferential members 136 . Thereby, an intermediate space 130 s is formed by the outer surface of the passage 131 and the inner surface of the side peripheral member 136 of the exterior body 132 .

The exterior body 132 has an ultrasonic transducer 133 attached to each surface of the hexagonal column formed by the side circumferential member 136 . The ultrasonic transducers 133 are divided into front and rear two stages in the extending direction of the passage 131, and the ultrasonic transducers 133 in the front stage are on the microbubble generating section 120 side, and the ultrasonic transducers in the rear stage are on the storage section 110 side. A vibrator 133 group is used.

A group of ultrasonic transducers 133 in each stage consists of six ultrasonic transducers 133 radially provided from the central axis of the passage 131 . Each ultrasonic transducer 133 is arranged to face each other, and the frequency and output of the generated ultrasonic waves can be adjusted by the control unit 1 . In this embodiment, the twelve ultrasonic transducers 133 irradiate ultrasonic waves with the same frequency and the same output.

Each of the ultrasonic transducers 133 in each stage irradiates ultrasonic waves toward one point in the center of the passage 131 . Therefore, an ultrasonic crushing field is formed in the center of the passage 131, and microbubbles of the microbubble-containing liquid passing through the passage 131 are crushed to generate ultrafine bubbles. In the passage crushing section 130, ultrasonic waves are irradiated from a plurality of directions, and an ultrasonic crushing field is formed at a place where the ultrasonic waves concentrate.

Therefore, in this embodiment, each stage of the ultrasonic transducer 133 group forms an ultrasonic crushing field in the passage 131 . By changing the frequency and output of the ultrasonic oscillator, it is possible to control the particle shape and concentration of ultrafine bubbles generated by crushing the fine bubbles.

[Reservoir]

3 shows a schematic diagram of the reservoir 110 shown in FIG. 1, FIG. 3(A) shows a schematic plan view of the reservoir 110, and FIG. 3(B) is a schematic cross-sectional view of 3B-3B in (A). indicates The storage section 110 is incorporated in the circulation path R1 by being introduced with the liquid containing ultrafine bubbles from the passage crushing section 130 and being connected to the filtration section 150 .

The storage unit 110 includes a storage tank 111 that stores liquid and has a capacity capable of cultivating fish and shellfish, and a plurality of liquid introduction pipes 112 that are connected to the passage crushing unit 130 and introduce liquid containing ultrafine bubbles into the storage tank 111. and an ultrasonic irradiation device 113 for applying ultrasonic waves to the liquid stored in the storage tank 111 . In this embodiment, the reservoir 110 has four liquid introduction tubes 112 .

The storage tank 111 has a side peripheral portion 111a and a bottom portion 111b so as to form a substantially cylindrical storage space 111s, and has an opening 111o that opens upward. A bottom portion 111b of the storage tank 111 is circular in plan view and is formed in a mortar shape that is slightly downwardly inclined in the radial direction toward the center, and foreign matter in the storage tank 111 gathers at the center. In addition, the storage tank 111 has an outlet port 114 at the center of the bottom portion 111b for leading out the stored liquid toward the circulation route R1, and an outlet port 115 at the bottom portion for discharging the stored liquid to the seawater inlet/outlet route D1. provided on the side of 111b.

The outlet port 114 functions as a bottom valve and is connected to the first pump 140 via the filtration section 150. The liquid in the storage tank 111 is sent to the first pump 140, and the liquid is added by the first pump. The pressurized liquid is supplied to the microbubble generator 120 . A detection unit 116 for detecting the dissolved gas concentration is provided near the outlet port 114 . The circumference of the outlet port 114 is formed as a concave portion 114a that is recessed downward. The concave portion 114 a acts to prevent the outlet port 114 from being clogged with impurities generated in the storage tank 111 .

Further, the discharge port 115 functions as a bottom valve and is connected to a second pump 190 via a discharge path crushing section 170. The liquid in the storage tank 111 is sent to the second pump 190, and the liquid is discharged. It is discharged to the sea area S via the second pump 190 . The periphery of the discharge port 115 is formed as a recess 115a recessed downward. The concave portion 115a prevents the impurities generated in the storage tank 111 from clogging the discharge port 115. As shown in FIG.

A liquid introduction pipe 112 of the reservoir 110 is provided around the opening of the reservoir 111 that opens upward. Each liquid introduction pipe 112 is mainly composed of a cylindrical pipe and is connected to the passage crushing portion 130 to introduce the microbubble-containing liquid containing ultrafine bubbles generated in the passage crushing portion into the storage tank 111 .

As shown in FIG. 4, in the storage part 110, the ultrafine bubble-containing liquid is discharged from the liquid introduction pipe 112 in a plan view clockwise (in the direction of the arrow r in FIG. By discharging the stored liquid from the outlet port 114 provided in the storage tank 111, the storage tank 111 forms a vortex T that rotates clockwise in the circumferential direction of the storage tank 111 from above to below.

A plurality of ultrasonic irradiation devices 113 are arranged on the side peripheral portion 111 a of the storage tank 111 . In this embodiment, four ultrasonic transducers 133 are attached to the storage tank 111 which is circular in plan view. These ultrasonic irradiation devices 113 are arranged facing each other so as to horizontally oscillate ultrasonic waves toward the center of the storage tank 111 . Each ultrasonic irradiation device 113 can adjust the frequency and output of the generated ultrasonic waves by the control unit 1 . In this embodiment, the four ultrasonic irradiation devices 113 all irradiate ultrasonic waves with the same frequency and the same output.

Since each ultrasonic irradiation device 113 irradiates ultrasonic waves toward the center of the storage tank 111, an ultrasonic collapse field W is formed in the center of the storage tank 111 (see FIG. 4). A high concentration of ultrafine bubbles is produced. A vortex T is formed around the central portion of the reservoir 111, and the generated ultrafine bubbles ride on the vortex T and are diffused throughout the reservoir 111 (in the direction of arrow d in FIG. 4). .

As a result, the ultrafine bubbles efficiently circulate throughout the storage tank 111 and come into contact with the object to be sterilized introduced into the storage section 110 . Therefore, in the storage tank 111 , ultrafine bubbles, particularly ultrafine bubbles with a particle size of 100 μm or less, can be directly acted on the object to be sterilized introduced into the storage tank 111 .

In addition, in the fish and shellfish cultured in the reservoir 110, ultrafine air bubbles contained in the liquid selectively adsorb viruses and the like in the body, desorb them from the body, and discharge them to the outside of the body. That is, it is sterilized by ultra-fine liquid bubbles. The sterilization of seafood will be described later.

The filtering unit 150 includes a conventionally well-known filter-type filtering device, and can collect impurities from the liquid circulating through the circulation route R1 and remove the impurities from the circulation route R1.

[Exhaust channel ultrasonic crushing part]
The discharge passage crushing section 170 is connected to the storage section 110 via a valve 180 , and a second pump 190 is connected to the opposite side of the valve 180 . Since the discharge path crushing section 170 has the same configuration as the passage crushing section 130, a detailed description of the configuration will be omitted.

The discharge path crushing section 170 opens the valve 180 between the storage section 110 and the storage section 110 as necessary to introduce and discharge the liquid. The valve 180 is closed when liquid is not introduced or discharged.

When the liquid, which is seawater, is introduced from the storage unit 110 to the discharge channel crushing unit 170, the discharge channel crushing unit 170 irradiates the introduced seawater with ultrasonic waves to kill germs, viruses, etc. remaining in the seawater. After that, the seawater is discharged to the sea area S by the second pump 190 . Since the discharged seawater is irradiated with ultrasonic waves to kill germs, viruses, and the like, it is possible to suppress the burden on the environment of the sea area S and adverse effects.

When the liquid, which is seawater, is drawn from the discharge passage crushing section 170 to the storage section 110 , the seawater pumped up from the sea area S by the second pump 190 is irradiated with ultrasonic waves and then drawn to the storage section 110 . The seawater led out to the reservoir 110 is irradiated with ultrasonic waves to kill germs, viruses, etc., so that it is possible to suppress the load and adverse effects on the seafood held in the reservoir 110.

In the microbubble sterilization system 100 according to the present embodiment, the reservoir 110, the microbubble generator 120, and the passage crusher 130 are incorporated in the circulation route R1, and the reservoir 110 is arranged in order from the upstream side in the liquid flow direction. The pump 140 is connected to the microbubble generating section 120 , the passage crushing section 130 is connected to the microbubble generating section 120 , and the storage section 110 is connected to the passage crushing section 130 . Further, a discharge path crushing section 170 is connected to the storage section 110 via a valve 180 , and the discharge path crushing section 170 is connected to the sea area S via a second pump 190 .

That is, in the circulation route R1, the liquid introduced from the sea area S through the second pump 190, the discharge passage crushing section 170 and the valve 180 into the storage section 110 passes through the microbubble generating section 120 and the passage crushing section 130. It is formed so as to return to the storage section 110 again. Since the liquid containing ultrafine bubbles returns, the content of ultrafine bubbles in the liquid retained in the reservoir 110 can be maintained high compared to the case where all the liquid is newly introduced from the sea area S.

[Control section]

Each part of the microbubble sterilization system 100 according to the present embodiment is controlled by the controller 1 . As shown in FIG. 1, the control unit 1 is connected to a microbubble generating unit 120, a passage crushing unit 130, a storage unit 110, a first pump 140, a second pump 190, a detecting unit 116, etc., and controls these units. Control.

The control unit 1 mainly controls the vibration output and vibration frequency of each ultrasonic transducer 133 for the passage crushing unit 130 . Further, the control unit 1 mainly controls the vibration output and vibration frequency of each ultrasonic irradiation device 113 with respect to the storage unit 110 . Furthermore, the controller 1 controls the discharge amounts of the first and second pumps 140 and 190 .

The control unit 1 also includes a target value setting unit (not shown), and can set a target value for the dissolved gas concentration of the liquid containing ultrafine bubbles stored in the storage unit. Further, the control unit 1 can detect, from the detection unit 116 , the measured value of the dissolved gas concentration of the ultrafine bubble-containing liquid stored in the storage unit 110 . Then, the control unit 1 adjusts the gas supply amount so that the target value and the measured value of the dissolved gas concentration of the ultrafine bubble-containing liquid stored in the storage unit 110 match. Specifically, the control unit 1 adjusts the gas supply amount by controlling a proportional control valve (not shown) provided in the gas supply unit.

The control unit 1 controls the measured value of the dissolved concentration of gas in the liquid containing microbubbles in the storage unit 110 detected by the detection unit 116 to be the concentration of the gas in the liquid containing microbubbles in the storage unit 110 set by the target value setting unit. Control the proportional control valve to match the dissolved concentration target. The control unit 1 adjusts the amount of gas supplied to the microbubble generating unit by so-called PID control using a proportional element, an integral element, and a differential element with respect to the gas supply amount adjustment unit. Further, the control unit 1 is set with constants of a proportional element, an integral element, and a differential element by a well-known auto-tuning function.

In the present embodiment, the passage 131 of the passage crushing portion 130 is formed of a pipe made of a fluororesin such as PFA or a PVC pipe, but it may be made of other resins. A metal that poses no problem in the above may be used as the material. Further, the passage crushing portion 130 has a two-layer structure consisting of the passage 131 and the exterior body 132, but may have another structure as long as it can crush microbubbles by irradiating ultrasonic waves. For example, a tubular member having a single-layer structure is formed from a metal such as titanium, which does not pose a problem in terms of hygiene and corrosion even when a liquid is passed through, and the ultrasonic transducer 133 is placed directly around the tubular member. The bubble-containing liquid may be passed through the inside of the cylindrical member.

In this embodiment, the liquid discharge pipe is arranged clockwise around the reservoir 111 to discharge the liquid containing ultra-fine bubbles. However, the liquid introduction tube 112 may be arranged to discharge liquid in any manner, for example, it may be arranged to discharge liquid counterclockwise, or it may be arranged to discharge liquid radially. You may make it Moreover, the shape of the storage tank may be a prismatic shape such as a substantially quadrangular prism or a substantially hexagonal prism.

In this embodiment, an ultrasonic crushing field is formed in the passage crushing section 130 and the storage section 110 to crush microbubbles contained in the liquid and convert them into ultrafine bubbles. The ultrasonic collapsing field is formed by continuously irradiating ultrasonic waves, and ultraviolet rays are generated in the ultrasonic collapsing field by the so-called sonoluminescence phenomenon. Therefore, the liquid passing through the ultrasonic crushing field can be sterilized by the ultraviolet rays.

Furthermore, in the passage crushing portion 130 and the storage portion 110, the liquid is irradiated with ultrasonic waves that form an ultrasonic crushing field, and a large number of vacuum bubbles are generated in the liquid by cavitation. When these vacuum bubbles repeatedly collapse and expand, a reaction field of ultra-high temperature and high pressure is formed. In this reaction field, the bursting of the vacuum bubbles destroys the cell walls of bacteria, resulting in the effect of killing viruses such as norovirus in addition to general viable bacteria, Legionella bacteria, Escherichia coli, and the like.

In particular, in the passage crushing section 130, there is no obstacle that obstructs the propagation of ultrasonic waves in the passage 131, and an ultrasonic crushing field is efficiently formed. As a result, since there are no obstacles such as objects to be sterilized in the passage where ultrasonic waves are irradiated, a strong ultrasonic crushing field is formed in the passage, and microbubbles in the liquid are effectively converted into ultrafine bubbles. can be crushed. Then, the liquid can be circulated while generating ultrafine bubbles, and the object to be sterilized can be introduced into the reservoir that stores the liquid containing the ultrafine bubbles and sterilized. As a result, ultrafine bubbles can be efficiently generated, and efficient sterilization can be performed by ultrasonic crushing energy.

On the other hand, in the reservoir 110, viruses, bacteria, etc. are detached from the fish and shellfish introduced into the reservoir 110 by ultrafine bubbles, and the liquid containing the desorbed viruses, bacteria, etc. is irradiated to the reservoir. Directly sterilized by ultrasound. As a result, detached viruses, bacteria, etc. can be prevented from returning to the fish and shellfish, and viruses, bacteria, etc. adhering to the object to be sterilized, which have been difficult to sterilize in the past, can be efficiently removed. .

[Example of method for sterilizing seafood]
Next, a method for sterilizing fish and shellfish according to an embodiment of the present invention will be described. In this sterilization method, the microbubble sterilization system 100 is used to sterilize seafood.

In the seafood sterilization method according to the embodiment of the present invention, seafood is cultured in seawater stored in the reservoir 110 of the microbubble sterilization system 100 . The seawater contains microbubbles and ultrafine bubbles of oxygen gas due to the operation of the reservoir 110, the microbubble generator 120, and the passage crusher 130 of the microbubble sterilization system 100, and the ultrafine bubbles are bubbles with a diameter of less than 100 nm. including.

In the sterilization method according to the present invention, seawater is first prepared in the reservoir 110 . Specifically, the second pump 190 operates to introduce seawater in the sea area into the reservoir 110 . At this time, bacteria and viruses in the seawater are killed by the operation of the discharge path crushing section 170 .

Next, seafood is introduced into the seawater stored in the storage unit 110 . Specifically, fish and shellfish are discharged from the opening 110o of the storage section 110 in which seawater is stored.

Next, the seawater stored in the storage part 110 is made to contain bubbles of oxygen gas. Specifically, the seawater stored in the storage unit 110 is supplied to the microbubble generation unit 120 by the operation of the first pump 140, and the seawater in which oxygen gas microbubbles are generated by the microbubble generation unit 120 passes through the passage. The seawater supplied to the crushing section 130 and converted from microbubbles to ultrafine bubbles in the passage crushing section 130 is returned to the storage section 110 .

The seawater stored in the storage unit 110 via the circulation path R1 contains oxygen gas bubbles with a particle size of less than 100 nm. Ordinarily, oxygen is simply dissolved in seawater by bubbling, but oxygen gas-containing seawater can be efficiently produced by incorporating the oxygen gas into the seawater as ultrafine bubbles. Seawater containing oxygen gas bubbles promotes the growth of fish and shellfish.

Next, the seawater stored in the storage part 110 is irradiated with ultrasonic waves to generate ultrafine bubbles. Specifically, the ultrafine bubble-containing liquid crushed by the passage crushing section 130 contains, in addition to the ultrafine bubbles, microbubbles that have not been crushed into ultrafine bubbles, and further crushes the ultrafine bubbles. , crushing the microbubbles into ultrafine bubbles.

By irradiating the reservoir 110 with ultrasonic waves, an ultrasonic crushing field is formed in the center of the reservoir, and the microbubbles contained in the seawater are crushed and converted into ultrafine bubbles, and the ultrasonic crushing field is continuous. Ultraviolet rays are generated in the ultrasonic collapsing field by the so-called sonoluminescence phenomenon. Therefore, the liquid itself stored in the storage part 110 can be sterilized by the ultraviolet rays.

Furthermore, in the storage part 110, the liquid is irradiated with ultrasonic waves that form an ultrasonic collapsing field, and a large number of vacuum bubbles are generated in the liquid by cavitation. When these vacuum bubbles repeatedly collapse and expand, a reaction field of ultra-high temperature and high pressure is formed. In this reaction field, the bursting of the vacuum bubbles destroys the cell walls of bacteria, resulting in the effect of killing viruses such as norovirus in addition to general viable bacteria, Legionella bacteria, Escherichia coli, and the like.

After the seafood is introduced into the reservoir 110, the seawater stored in the reservoir 110 is made to contain oxygen gas bubbles, and the seawater stored in the reservoir 110 is irradiated with ultrasonic waves to form ultrafine bubbles. The step of generating may be performed simultaneously or alternately.

In the microbubble sterilization system 100 according to the embodiment of the present invention, viruses accumulated in the bodies of fish and shellfish are selectively adsorbed and desorbed by ultrafine bubbles, and discharged from the bodies of fish and shellfish, that is, bacteria are eliminated. Then, the discharged virus is killed by ultrasonic waves in the ultrasonic crushing unit. Conventional chemical sterilization using hypochlorous acid or the like can kill bacteria and viruses by mixing chemical solutions into seawater, but it also adversely affects seafood. However, like the microbubble sterilization system 100 for fish and shellfish according to the embodiment of the present invention, physical sterilization using ultrasonic waves does not affect fish and shellfish.

In this way, the fish and shellfish cultured in the reservoir 110 excrete the viruses in the body to the outside by the selective adsorption and desorption action of the ultrafine bubbles in the process. Viruses and bacteria are sterilized by ultrasonic irradiation in the storage part 110 and the passage crushing part 130, so that the seafood can be reliably sterilized and shipped to the market in a safe state.

[Observation results of ultrafine bubbles]
Next, the results of observing ultrafine bubbles generated by the passage crushing section 130 according to the embodiment of the present invention will be described. A high-speed atomic force microscope (high-speed AFM) was used to observe the ultrafine bubbles.

Observation conditions are as follows.
Equipment: High-speed atomic force microscope NanoExplorer
Observation environment: Room temperature (21°C)
Cantilever: BL-AC10DS-A2 (Olympus, Japan)
Resolution: 200 x 200 pixels Observation image: AC mode shape image in liquid Nanobubbles are generally known to have a negative charge, and substrates with a positive charge (PLL-mica substrate and APTES-mica substrate) are used. and observed.

5 and 6 show the observation results of ultrafine bubbles observed using the PLL-mica substrate, each figure (A) shows an observation photograph, and each figure (B) is on the white line in (A) Shows a height graph. The position of the triangular mark on the white line shown in (A) of each figure corresponds to the position of the triangular mark on the graph of (B). Here, PLL (Poly-L-Lysine) is an amino acid lysine polymer. Lysine has an amino group and has a positive charge. Therefore, by covering negatively charged mica with a PLL, the mica surface can be given a positive charge.

FIG. 5A shows an observation photograph under the condition that the scanning range is 500 nm, and FIG. 6A shows an observation photograph under the condition that the scanning range is 200 nm. According to FIG. 5(B), FIG. 5(A) shows that particles with a height of 20.9 nm and a length in the white line direction of 75.4 nm were observed, and according to FIG. 6(B) FIG. 6A shows that particles with a height of 23.0 nm and a length in the white line direction of 59.5 nm were observed. In this observation using the PLL-mica substrate, the height of the particles is considered to be the particle size, and as a whole, about one particle with a particle size of about 20 nm was observed in the range of 500 nm×500 nm.

7 and 8 show the observation results of ultrafine bubbles observed using the APTES-mica substrate, each figure (A) shows an observation photograph, and each figure (B) is on the white line in (A) Shows a height graph. The position of the triangular mark on the white line shown in (A) of each figure corresponds to the position of the triangular mark on the graph of (B). Here, APTES (3-aminopropyl triethoxy silane) exposes amino groups on the substrate surface by bonding ethoxy groups to hydroxyl groups on mica. This allows the mica surface to have a positive charge.

FIGS. 7A and 8A show observation photographs under the condition that the scanning range is 500 nm. According to FIG. 7(B), FIG. 7(A) shows that particles with a height of 15.7 nm and a length in the white line direction of 75.4 nm were observed, and FIG. 8(B) shows that , FIG. 8(A) shows that particles with a height of 8.57 nm and particles with a height of 4.53 nm were observed. In this observation using the APTES-mica substrate, the particle size is considered to be the height of the particles, and as a whole, a plurality of particles with a particle size of 20 nm or less and different particle sizes were observed within a range of 500 nm×500 nm.

From the above observation results, particles with a particle size of several nm to several tens of nm were observed. Since nanobubbles have been observed on similar positively charged substrates in the past, the observed particles are considered to be nanobubbles. It can be seen that the above nanobubbles are generated in the liquid.

[Second embodiment]

A microbubble sterilization system 200 according to a second embodiment according to an embodiment of the present invention will be described with reference to FIGS. 9 and 10. FIG. The microbubble sterilization system 200 uses microbubbles or ultrafine bubbles to sterilize an object to be sterilized, and in this embodiment, a system in which the object to be sterilized is a beverage will be described.

FIG. 9 shows a functional block diagram of the microbubble sterilization system 200. As shown in FIG. As shown in FIG. 9, the microbubble sterilization system 200 includes a storage unit 210 that stores liquid, and a microbubble generation unit 220 that is connected to the storage unit 210 and generates microbubbles in the liquid supplied from the storage unit 210. Prepare. In this embodiment, the microbubble sterilization system 200 does not include the passage crushing section 130 and the filtering section 150 of the microbubble sterilization system 100 .

In this embodiment, a beverage is used as the liquid and carbon dioxide is used as the gas, but the types of liquid and gas can be changed as appropriate. For example, even when the object to be sterilized is a beverage, nitrogen may be applied to the gas to have the effect of maintaining the flavor.

The reservoir 210 and the microbubble generator 220 are connected to each other to form a circulation path R2 for circulating the liquid. A first pump 240 is arranged between the reservoir 210 and the microbubble generator 220 to supply liquid from the reservoir 210 to the microbubble generator 220 . The first pump 240 is connected to the gas supply unit 260, mixes the gas supplied from the gas supply unit 260 with the liquid, and supplies the liquid to the microbubble generator.

The microbubble sterilization system 200 includes an undiluted liquid supply section 290 for introducing an undiluted liquid, a pressurizing section 280 for pressurizing the storage section 210, and an outlet section 270 for extracting the liquid. The undiluted solution supply unit 290 is connected to, for example, a tank storing milk before sterilization, and can supply the milk to the microbubble sterilization system 200 . The pressurizing unit 280 can be connected to a pressurizing device such as a compressor to pressurize the storage unit 210 .

Also, the lead-out portion 270 is connected to the lead-out port 214 of the storage portion 210 and can be used when taking out the beverage. The outlet part 270 and the microbubble generator 220 are connected to the outlet port 214 of the storage part 210 via a switching valve (not shown). Therefore, the liquid stored in the storage section 210 is controlled by the switching valve between the state of circulating through the circulation route R2 and the state of being taken out from the lead-out section 270 . The switching valve is connected to the control unit 1 and controlled to switch.

Like the microbubble sterilization system 100, the microbubble sterilization system 200 is centrally managed by the controller 1. FIG. In FIG. 9, connections between the control unit 1 and each unit managed by the control unit 1 are indicated by dashed lines. The control unit 1 may control the microbubble sterilization system 200 in cooperation with an external control device or the like. Also, each part of the microbubble sterilization system 200 may be controlled by another control device or the like.

[Micro bubble generator]

The microbubble sterilization system 200 includes a conventionally well-known swirling flow type fine bubble generator as the microbubble generator 220 (see, for example, Japanese Patent No. 6123013). The microbubble generating section 220 includes a swirling section (not shown), a projection crushing section (not shown), a breeding section (not shown), and a foaming section (not shown).

The microbubble generating unit 220 applies the functions of swirling, crushing, feeding, and foaming (pressurization and decompression) to the gas-mixed liquid supplied from the first pump 240 to generate microbubbles. . In such a swirling flow type fine bubble generator, the pressure of the liquid supplied from the first pump 240, the pressure applied in the livestock section, and the particle size of the microbubbles generated by the structure of the foaming section are controlled. can do.

[Reservoir]

10 shows a schematic diagram of the storage section 210 shown in FIG. 9, FIG. 10A shows a schematic plan view of the storage section 210, and FIG. 10B is a schematic cross-sectional view taken along 10B-10B in (A) indicates Reservoir 210 is incorporated in circulation route R2. Therefore, the storage part 210 receives the liquid from the microbubble generating part 220 and discharges the liquid to the microbubble generating part 220 through the outlet 214 .

The storage unit 210 stores liquid and is connected to a storage tank 211 having a predetermined capacity, an outer tank 217 covering the storage tank 211, and a microbubble generating unit 220 to introduce the microbubble-containing liquid into the storage tank 211. It includes a liquid inlet 212 , an ultrasonic irradiation device 213 for applying ultrasonic waves to the liquid stored in the storage tank 211 , and an outlet 214 for leading out the liquid stored in the storage section 210 .

The storage tank 211 includes a side peripheral portion 211a and a bottom portion 211b so as to form a substantially cylindrical housing space 211s. A bottom portion 211b of the storage tank 211 has a circular shape in a plan view and is slightly inclined downward in the radial direction toward the center, so that foreign substances in the storage tank 211 gather at the center. In addition, the storage tank 211 has an outlet port 214 at the center of the bottom portion 211b for leading out the stored liquid toward the circulation route R2. The outlet port 214 is also connected to the outlet part 270, and can also lead the liquid to the outside. The outlet port 214 functions as a bottom valve, sends the liquid in the storage tank 211 to the first pump 240 , and supplies the liquid pressurized by the first pump 240 to the fine bubble generator 220 .

The storage tank 211 is covered with an outer tank 217, and has a two-layer structure with an intermediate space 217s between the storage tank 211 and the outer tank 217. As shown in FIG. A plurality of ultrasonic wave irradiation devices 213 are provided in the outer tank 217, and the ultrasonic wave irradiation devices 213 are arranged facing each other and emit ultrasonic waves toward the center of the storage tank 211. Functions as an irradiation unit.

An intermediate space 217s between the storage tank 211 and the outer tank 217 is filled with a transmitting liquid, and ultrasonic waves emitted from the ultrasonic irradiation device 213 are propagated into the storage tank 211 via the transmitting liquid, and are stored. A crushing field is formed in the liquid stored inside the tank 211 to crush the microbubbles. In this embodiment, eight ultrasonic irradiation devices 213 are attached to the side of the outer tank 217 at regular intervals.

The medium liquid is cooling water supplied from a cooling water supply unit (not shown) such as a chiller, and introduced into the intermediate space 217s from a medium liquid inlet 217a provided at the bottom of the outer tank 217. is led out from a propagating liquid lead-out port 217b provided at the upper end of the side portion of the . In the storage tank 211, the intermediate space 217s is filled with the medium liquid (cooling water), and the ultrasonic wave irradiation from the ultrasonic wave irradiation device 213 is propagated to the medium liquid, and the liquid stored in the storage tank 211 is heated. be.

Here, since the medium also has the effect of cooling the storage tank 211, the temperature of the liquid stored in the storage tank 211 can be adjusted by adjusting the flow rate of the medium flowing through the intermediate space 217s. The storage tank 211 and the outer tank 217 are made of stainless steel or the like.

Further, the reservoir 210 has an openable and closable upper lid 219, and the reservoir 211 is hermetically sealed when the upper lid 219 is closed. The upper lid 219 has a pressurizing port 219a connected to the pressurizing section, a gas exhaust port 219b connected to the vent filter, and a liquid inlet 219c connected to the liquid supplying section. The storage tank 211 has a sealed structure by closing the upper lid, is pressurized through a pressurization port 219a attached to the upper lid, and is adjusted in pressure through a gas discharge port 219b connected to a vent filter. The liquid stock solution is supplied to the stock solution inlet 219c.

Furthermore, the storage unit 210 includes a stirrer 218 that stirs the liquid stored in the storage tank 211 . The stirrer 218 includes a motor 218a attached to the top cover 219, a shaft 218b connected to the motor 218a, and stirring blades 218c attached to the shaft 218b. The motor 218a is connected to the control unit 1, and the timing of driving is controlled.

[Example of beverage sterilization method]

Next, a beverage sterilization method according to an embodiment of the present invention will be described. In this sterilization method, the microbubble sterilization system 200 is used to sterilize the beverage.

In the beverage sterilization method according to the embodiment of the present invention, the beverage stored in the reservoir 210 of the microbubble sterilization system 200 is sterilized. The beverage contains microbubbles and ultrafine bubbles of carbon dioxide gas due to the operation of the reservoir 210 and microbubble generator 220 of the microbubble sterilization system 200, and the ultrafine bubbles include bubbles with a diameter of less than 100 nm.

In the sterilization method according to the present invention, first, a beverage is prepared in the reservoir 210 . Specifically, the beverage is introduced into the storage section 210 from the concentrate supply source via the concentrate supply section 290 .

Next, the beverage stored in the storage part 210 is made to contain bubbles of oxygen gas. Specifically, the beverage stored in the storage unit 210 is supplied to the fine bubble generation unit 220 by the operation of the first pump 240, and the fine bubbles of oxygen gas are generated in the fine bubble generation unit 220. Return to reservoir 210 . The beverage thereby contains microbubbles.

Next, the beverage stored in the storage part 210 is irradiated with ultrasonic waves to generate ultrafine bubbles. Specifically, by irradiating the reservoir 210 with ultrasonic waves, an ultrasonic crushing field is formed in the center of the reservoir 211, and microbubbles contained in the beverage are crushed and converted into ultrafine bubbles. Thereby the beverage contains microbubbles and ultrafine bubbles. The ultrasonic collapsing field is formed by continuously irradiating ultrasonic waves, and ultraviolet rays are generated in the ultrasonic collapsing field by the so-called sonoluminescence phenomenon. Therefore, the ultraviolet sterilization effect can be obtained for the liquid itself stored in the storage part 210 .

Furthermore, in the storage part 210, the liquid is irradiated with ultrasonic waves that form an ultrasonic collapsing field, and a large number of vacuum bubbles are generated in the liquid by cavitation. When these vacuum bubbles repeatedly collapse and expand, a reaction field of ultra-high temperature and high pressure is formed. In this reaction field, the bursting of the vacuum bubbles destroys the cell walls of bacteria, resulting in the effect of killing common viable bacteria, Legionella, Escherichia coli, and viruses such as norovirus.

After the beverage is introduced into the storage unit 210, the beverage stored in the storage unit 210 is made to contain carbon dioxide gas bubbles, and the beverage stored in the storage unit 210 is irradiated with ultrasonic waves to form ultrafine bubbles. The step of generating may be performed simultaneously or alternately. Further, the stirrer 218 can be driven to stir the liquid in the reservoir 210 both when the beverage is introduced into the reservoir 210 and after the beverage is introduced.

Conventional heat sterilization has adverse effects on beverages, such as deterioration of the flavor of beverages. However, as in the beverage microbubble sterilization system 200 according to the embodiment of the present invention, non-heating physical sterilization using ultrasonic waves does not adversely affect beverages. Further, by selecting the type of gas of fine bubbles or ultrafine bubbles, it is possible to further suppress the deterioration of the flavor of the beverage.

[Third Embodiment]

A microbubble sterilization system 300 according to a third embodiment according to an embodiment of the present invention will be described with reference to FIGS. 11 and 12. FIG. The microbubble sterilization system 300 uses microbubbles or ultrafine bubbles to sterilize objects to be sterilized, and in this embodiment, a system in which food is the object to be sterilized will be described. The microbubble sterilization system 300 can sterilize foods such as vegetables, meat, eggs, sesame seeds, and adzuki beans.

FIG. 11 shows a functional block diagram of the microbubble sterilization system 300. As shown in FIG. As shown in FIG. 11, the microbubble sterilization system 300 includes a storage section 310 that stores liquid, and a microbubble generation section 320 that is connected to the storage section 310 and generates microbubbles in the liquid supplied from the storage section 310. , a passage crushing part 330 connected to the microbubble generating part 320 and irradiating ultrasonic waves while allowing the microbubble-containing liquid containing microbubbles to pass therethrough to crush the microbubbles and generate ultra-microbubbles. In this embodiment, the microbubble sterilization system 300 does not include the filtering section 150 of the microbubble sterilization system 100 .

In this embodiment, tap water is used as liquid and carbon dioxide is used as gas, but the types of liquid and gas can be changed as appropriate. For example, even when food is an object to be sterilized, nitrogen may be applied to the gas to have the effect of maintaining flavor.

The reservoir 310, the microbubble generator 320, and the passage crusher 330 are interconnected to form a circulation path R3 for circulating the liquid. A first pump 340 is arranged between the reservoir 310 and the microbubble generator 320 to supply liquid from the reservoir 310 to the microbubble generator 320 . The first pump 340 is connected to the gas supply unit 360, mixes the gas supplied from the gas supply unit 360 with the liquid, and supplies the liquid to the microbubble generator.

The microbubble sterilization system 300 includes a stock solution supply part 390 for introducing a stock solution of liquid and a lead-out part 370 for drawing out the liquid. The stock solution supply 390 is connected to, for example, a conventional well-known water supply device, and can supply water to the microbubble sterilization system 300 .

Also, the lead-out portion 370 is connected to the lead-out port 314 of the storage portion 310 and can be used to take out the liquid. The lead-out part 370 and the microbubble generator 320 are connected to the lead-out port 314 of the storage part 310 via a switching valve (not shown). Therefore, the liquid stored in the storage section 310 is controlled by the switching valve between the state of circulating through the circulation path R3 and the state of being taken out from the lead-out section 370 . The switching valve is connected to the control unit 1 and controlled to switch.

Like the microbubble sterilization system 300, the microbubble sterilization system 300 is centrally managed by the controller 1. FIG. In FIG. 11, connections between the control unit 1 and each unit managed by the control unit 1 are indicated by dashed lines. The control unit 1 may control the microbubble sterilization system 300 in cooperation with an external control device or the like. Also, each part of the microbubble sterilization system 300 may be controlled by another control device or the like.

The microbubble sterilization system 300 includes a nozzle-type fine bubble generator similar to the microbubble generator 320 according to the first embodiment, and a passage crusher 330 similar to the passage crusher 330 according to the first embodiment. Prepare. Since these configurations are the same as those of the first embodiment, description thereof is omitted.

[Reservoir]

FIG. 12 shows a schematic cross-sectional side view of the reservoir 310 shown in FIG. Reservoir 310 is incorporated in circulation route R3. Therefore, the reservoir 310 receives the liquid from the microbubble generator 320 via the passage crushing section 330 and discharges the liquid to the microbubble generator 320 through the outlet 314 .

The storage unit 310 stores a liquid and includes a storage tank 311 having a predetermined capacity, a liquid introduction pipe 312 connected to the microbubble generation unit 320 and introducing the microbubble-containing liquid into the storage tank 311, and the storage unit 310. and an outlet port 314 for leading out the stored liquid. Unlike the storage units 110 and 210 according to the first and second embodiments, the storage unit 310 according to this embodiment does not include an ultrasonic irradiation unit.

However, the storage part 310 may be provided with an ultrasonic irradiation part similar to the storage part 210 according to the second embodiment. Then, an ultrasonic wave can be applied by the ultrasonic wave applying unit to form an ultrasonic collapsing field in the storage tank 311 . In that case, the position of holding the food may be adjusted so that the food is positioned near the ultrasonic crushing field, or the food may be positioned away from the ultrasonic crushing field. For example, by changing the depth of the holding portion 319, the position at which the food is held can be adjusted.

The storage tank 311 has a side peripheral portion 311a and a bottom portion 311b so as to form a substantially cylindrical storage space 311s, and has an opening 311o that opens upward. A bottom portion 311b of the storage tank 311 is circular in plan view and is formed so as to be slightly downwardly inclined in the radial direction toward the center, so that foreign matter in the storage tank 311 gathers at the center. In addition, the storage tank 311 has an outlet port 314 at the center of the bottom portion 311b for leading out the stored liquid toward the circulation route R3. The outlet port 314 is also connected to the outlet portion 370 and can also lead the liquid to the outside.

The outlet port 314 functions as a bottom valve, sends the liquid in the storage tank 311 to the first pump 340 , and supplies the liquid pressurized by the first pump 340 to the fine bubble generator 320 .

The storage tank 311 is covered with an outer tank 317 and has a two-layer structure with an intermediate space 317s between the storage tank 311 and the outer tank 317 . An intermediate space 317s between the storage tank 311 and the outer tank 317 is filled with the propagating liquid. The medium liquid is cooling water supplied from a cooling water supply unit (not shown) such as a chiller, and is introduced into the intermediate space 317s from a medium liquid introduction port 317a provided at the bottom of the outer tank 317. is led out from a propagating liquid lead-out port 317b provided at the upper end of the side portion of the . In the storage tank 311, the intermediate space 317s is filled with the medium liquid (cooling water) and flows.

Here, since the medium also has the effect of cooling the storage tank 311, the temperature of the liquid stored in the storage tank 311 can be adjusted by adjusting the flow rate of the medium flowing through the intermediate space 317s. The storage tank 311 and the outer tank 317 are made of stainless steel or the like.

The storage part 310 further includes a holding member 319 arranged within the storage space 311 s of the storage tank 311 . The holding member 319 is a so-called mesh-like (not shown) basket with a plurality of holes formed on the entire surface, and holds the object to be sterilized in the storage tank 311 . The holding member 319 is made of stainless steel.

The holding member 319 includes a bottom portion 319a having substantially the same shape as the opening 311o of the storage tank 311, and a side circumference portion 319b extending upward from the side circumference of the bottom portion 319a. A side peripheral portion 319b of the holding portion 319 has a folded portion 319c whose upper end is folded outward.

In this embodiment, the object to be sterilized can be held by the holding member 319 and introduced into the reservoir 311 . By adjusting the length of the side peripheral portion 319b of the holding member 319, the height of the bottom portion 319a inside the storage tank is changed. be able to. Note that the holding member may have another configuration as long as it can hold the object to be sterilized.

[Example of food sterilization method]

In the food sterilization method according to the embodiment of the present invention, the food is held in the liquid stored in the reservoir 310 of the microbubble sterilization system 300 . The liquid contains microbubbles and ultrafine bubbles of carbon dioxide gas due to the operation of the reservoir 310, the microbubble generator 320, and the passage crusher 330 of the microbubble sterilization system 300, and the ultrafine bubbles are less than 100 nm in diameter. Contains air bubbles.

In the sterilization method according to the present invention, liquid is first prepared in the reservoir 310 . More specifically, the liquid is introduced into the storage section 310 from the raw liquid supply through the raw liquid supply section 390 .

Next, food is introduced into the liquid stored in storage part 310 . Specifically, the holding member 319 holding the food is introduced from above, which is open to the storage section 310 in which the liquid is stored.

Next, the liquid stored in the storage part 310 is made to contain bubbles of carbon dioxide gas. Specifically, the liquid stored in the storage unit 310 is supplied to the fine bubble generation unit 320 by the operation of the first pump 340, and the liquid in which fine bubbles of carbon dioxide gas are generated in the fine bubble generation unit 320 is The liquid supplied to the passage crushing section 330 and converted from microbubbles to ultrafine bubbles in the passage crushing section 330 is returned to the storage section 310 .

After the food is introduced into the storage part 310, the liquid stored in the storage part 310 is made to contain oxygen gas bubbles, and the liquid stored in the storage part 310 is irradiated with ultrasonic waves to generate ultrafine bubbles. may be performed simultaneously or alternately.

In the microbubble sterilization system 300 according to the embodiment of the present invention, viruses and bacteria adhering to food are selectively adsorbed and detached by microbubbles or ultra-microbubbles, and removed from the food, that is, sterilized. Then, the eliminated virus is killed by ultrasonic waves in the ultrasonic crushing section. In the conventional chemical sterilization using hypochlorous acid or the like, it is possible to kill various bacteria and viruses by mixing a liquid with a chemical solution, but at the same time, it also adversely affects food. However, physical sterilization using ultrasonic waves, like the food microbubble sterilization system 300 according to the embodiment of the present invention, does not affect the food.

In this way, the food held in the storage part 310 is freed from viruses in the body by the selective adsorption/desorption action of the ultrafine bubbles in the process. Viruses and bacteria are sterilized by ultrasonic irradiation in the storage part 310 and the passage crushing part 330, so that the food can be reliably sterilized and shipped to the market in a safe state.

Viruses and bacteria that are sterilized by the microbubble sterilization system and sterilization method according to the embodiment of the present invention differ in shape and size depending on the type. For example, iridovirus is a coccus with a diameter of about 200 nm and inhabits inside sea bream, yellowtail, etc., Vibrio parahaemolyticus is a bacillus with a diameter of about 1 μm and inhabits commonly in fish, and norovirus is a coccus with a diameter of about 30 nm and lives in oysters. Inhabits bivalves such as scallops, E. coli is a rod-shaped bacterium with a long diameter of around 2 μm to 4 μm and inhabits vegetables, beverages such as milk, grains, etc. Salmorella is a rod-shaped bacterium with a diameter of around 2 μm and lives in meat and eggs of livestock. Campylobacter is a spiral-shaped bacillus with a diameter of about 2 μm and inhabits livestock meat. Staphylococcus aureus is a coccus with a diameter of about 1 μm and inhabits vegetables, fruits, and milk. , known to inhabit milk and others.

According to the microbubble sterilization system and sterilization method according to the embodiment of the present invention, the generation of microbubbles and ultrafine bubbles that easily adsorb and desorb viruses and bacteria can be controlled depending on the shape and size of viruses and bacteria. That is, it is possible to effectively desorb viruses and bacteria from the object to be sterilized by controlling the particle size of the microbubbles and ultrafine bubbles according to the viruses and bacteria contained in the object to be sterilized. In addition, it is effective not only for viruses and bacteria, but also for organisms such as parasites.

It should be noted that the configurations shown in the above embodiments are specific examples of constituent elements, and each configuration, shape, or mounting mode is limited to those shown as embodiments unless they deviate from the gist of the present invention. Various modifications and changes are possible.

INDUSTRIAL APPLICABILITY The present invention can be used for ultrasonic sterilization systems and sterilization methods.

100 microbubble sterilization system 110 storage unit 112 liquid introduction pipe 113 ultrasonic irradiation device (ultrasonic irradiation unit)
114 Outlet 120 Microbubble generating section 130 Passage crushing section 133 Ultrasonic vibrator (ultrasonic irradiation section)
160 supply unit 200 microbubble sterilization system 210 storage unit 212 liquid inlet 213 ultrasonic irradiation device (ultrasonic irradiation unit)
220 Microbubble generation unit 260 Gas supply unit 270 Derivation unit 300 Microbubble sterilization system 310 Storage unit 312 Liquid introduction pipe 319 Holding member 320 Microbubble generation unit 330 Passage crushing unit 360 Gas supply unit 370 Derivation unit R1 Circulation path R2 Circulation path R3 circulation path

Claims (6)

a microbubble generating unit that generates microbubbles in a liquid;
a storage unit that stores the liquid;
a passage interposed between the microbubble generating portion and the storing portion;
a first ultrasonic wave irradiation unit provided in the passage for irradiating the liquid containing the microbubbles and passing through the passage with ultrasonic waves to crush the microbubbles to generate ultrafine bubbles;
a second ultrasonic wave irradiation unit provided in the reservoir for irradiating the liquid containing the microbubbles and introduced into the reservoir with ultrasonic waves to crush the microbubbles to generate ultrafine bubbles; with
A microbubble sterilization system in which a circulation path for circulating the liquid is formed by the reservoir, the microbubble generator, and the passage,
The storage unit is introduced with seafood as an object to be sterilized, and includes a storage tank for storing the liquid and a holding member for holding the object to be sterilized,
A microbubble sterilization system, characterized in that microbubbles or ultrafine bubbles desorb viruses or bacteria from the object to be sterilized. a microbubble generating unit that generates microbubbles in a liquid;
a storage unit that stores the liquid;
a passage interposed between the microbubble generating portion and the storing portion;
a first ultrasonic wave irradiation unit provided in the passage for irradiating the liquid containing the microbubbles and passing through the passage with ultrasonic waves to crush the microbubbles to generate ultrafine bubbles;
a second ultrasonic wave irradiating unit provided in the reservoir for irradiating the liquid containing the microbubbles and introduced into the reservoir with ultrasonic waves to crush the microbubbles to generate ultrafine bubbles; with
A microbubble sterilization system in which a circulation path for circulating the liquid is formed by the reservoir, the microbubble generator, and the passage,
The storage unit is introduced with food as an object to be sterilized, and includes a storage tank for storing the liquid and a holding member for holding the object to be sterilized,
A microbubble sterilization system, characterized in that microbubbles or ultrafine bubbles desorb viruses or bacteria from the object to be sterilized. The storage unit includes a storage tank that stores the liquid,
The storage tank is provided with a bottom, an outlet formed substantially in the center of the bottom for discharging the liquid stored in the storage tank, and a plurality of the ultrasonic irradiation units, which continue upward from the bottom. and a side perimeter;
The storage tank forms a vortex that rotates toward the bottom part around the outlet by discharging the liquid from the outlet,
The plurality of ultrasonic irradiation units irradiate ultrasonic waves toward the center of the vortex,
3. The microbubble sterilization system according to claim 1, wherein the microbubbles or ultrafine bubbles desorb viruses or bacteria from the object to be sterilized. The storage tank further comprises an opening that serves as the upper end of the side circumference,
4. The microbubble sterilization system according to claim 3, wherein the liquid is introduced in the circumferential direction from the periphery of the opening. a preparation step of preparing a liquid in the reservoir;
an introduction step of holding the food held by the holding member in the holding portion of the storage portion;
a microbubble generating step of causing the liquid to contain microbubbles of carbon dioxide gas;
An ultrasonic crushing step of irradiating the liquid containing the microbubbles and the food with ultrasonic waves,
In the ultrasonic crushing step, the microbubbles are crushed by ultrasonic waves to generate ultrafine bubbles, and the food is sterilized,
A method for sterilizing food, characterized in that microbubbles or ultrafine bubbles desorb viruses or bacteria from the object to be sterilized. a preparation step of preparing a liquid in the reservoir;
an introduction step of holding the seafood held by the holding member in the holding portion of the storage portion;
a microbubble generating step of causing the liquid to contain microbubbles of carbon dioxide gas;
An ultrasonic crushing step of irradiating the liquid containing the microbubbles and the food with ultrasonic waves,
In the ultrasonic crushing step, the microbubbles are crushed by ultrasonic waves to generate ultrafine bubbles, and the seafood is sterilized,
A method for sterilizing fish and shellfish, characterized in that microbubbles or ultrafine bubbles desorb viruses or bacteria from the object to be sterilized.

Images