JP2002045159A - Electron beam sterilization device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electron beam sterilization device which uses an air slide of a porous member as a carrying means, and irradiates granular food materials with electron beams on rotating the granular food material, to enhance the effect of the sterilization. SOLUTION: This electron beam sterilization device characterized by comprising a closed chamber 14, a porous member 15 obliquely disposed in the chamber to divide the chamber into the upper and lower portions, a fluid charged below the porous member 15, and an electron beam irradiation device 1 for irradiating electron beams 2 on the granular food material 5 carried on the porous member 15 along the slope with the fluid. The granular food material 5 is carried with the pressure of the fluid on the porous member 15, and the electron beams 2 are irradiated around the granular food material 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron beam sterilizer for sterilizing by irradiation with an electron beam while transporting food raw materials (granular food materials) such as grains, spices, and beans.

[0002]

2. Description of the Related Art In general, among foods used as raw materials for processed foods, in the case of dry food raw materials such as grains such as wheat, shelled buckwheat, brown rice, spices and beans, bacteria and the like are contained in the dried food raw materials. Microorganisms cannot penetrate, so that the microorganisms adhere only to the surface of the food raw material. These microorganisms often form spores, which are cells having high heat resistance, and have high resistance to heat treatment, bactericides, drying, and the like, so that complete sterilization was difficult.

[0003] For this reason, electron beam sterilization has been proposed as a non-heat sterilization technique that can surely sterilize microorganisms that contaminate the surface of food raw materials without deteriorating the quality of the food raw materials. In this electron beam sterilization, low energy electron beams (especially 30
0 keV or less), the electron beam rapidly loses energy on the surface of the food particles and does not reach the inside,
It is known that the effect on the internal quality of the food particles is minimized and that microorganisms on the surface of the food particles can be effectively killed.

FIG. 5 is a conceptual diagram showing an example of a conventional electron beam sterilizer for supplying food raw materials (granular food material) into a chamber and irradiating an electron beam while transporting the same to sterilize the granular food material. FIG. As shown in FIG. 5, a powdered food material 5 which is a powdered food raw material is charged into the supply hopper-4,
An appropriate amount of the granular food material 5 is continuously cut out from the supply hopper 4 by the cutting device 6 and sent to the inlet side of the chamber 3. In the chamber-3, the electron beam 2 is irradiated by the electron beam irradiating device 1 while the granular material 5 is conveyed from right to left in FIG. 5 by conveying means such as a belt conveyor. Thereby, the surface or the vicinity of the surface of the granular food material 5 is sterilized by the electron beam 2.

[0005] Then, the sterilized powdery and granular food material 7 is taken out from the chamber-3 outlet (left side in the figure) and sent to the next step.

[0006]

In the conventional electron beam sterilizing apparatus as described above, it is difficult to irradiate the whole surface of the granular material 5 with the electron beam while transporting the granular material 5 by the transport means. However, there is a problem that irradiation unevenness easily occurs partially. Further, as a conveying means, JP-A-11-109
Japanese Unexamined Patent Publication No. H11-100 discloses a conveying method using a belt conveyor, and Japanese Patent Laid-Open No. 11-101900 discloses a conveying method using a screw conveyor.
No. 100 discloses a method of dropping a thin film, etc., but it has been difficult to irradiate the entire surface of the granular material having a significant shape with an electron beam. For this reason, a sufficient sterilization effect may not be obtained due to irradiation unevenness.

According to the present invention, an air slide using a perforated plate is used as a conveying means, and an electron beam is irradiated on the entire surface of the granular food material while rotating the granular food material, thereby providing a high sterilizing effect. It is intended to provide an electron beam sterilizer.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a sealed chamber and a chamber.
And a porous body to which the powder is supplied on the upper surface, and the powder supplied to the lower side of the porous body and supplied to the upper surface of the porous body, is ejected from the holes of the porous body. A fluid to be conveyed along the inclined surface of the porous body by fluid pressure, and an electron beam irradiation device for irradiating the granular material conveyed on the upper surface side of the porous body with an electron beam, and air blown out of the perforated plate The powder or the like is levitated by a fluid such as described above, conveyed while rotating, and irradiated around the powder with a uniform electron beam to sterilize the powder or the particle. Further, the present invention provides a sealed chamber for performing electron beam irradiation treatment on the granular material,
A vibratory feeder for vibrating the granular material supplied into the chamber and diffusing it into a thin layer (single layer), and a perforated plate having a mesh-like opening hole inclined in the chamber. A blower for sending air below the perforated plate, a continuous cutting device provided at a supply port of the granular material to the chamber,
A continuous cutting device provided at a discharge port of the granular material from the chamber; and an electron beam irradiation device for irradiating the granular material being conveyed on the perforated plate with an electron beam. The powder or the like is diffused on the perforated plate by the fluid such as air to be blown out, floats on the perforated plate, transports it while rotating, and irradiates the periphery of the powder with the electron beam evenly around the perimeter. It is to sterilize microorganisms such as attached bacteria. Further, an ozone removing device for removing ozone generated in the chamber can be provided on the outlet side of the chamber. Still further, the chamber and the electron beam irradiation device
A fluid ejection nozzle that is directly connected via a window foil provided at the boundary portion and cools the window foil can be provided. Also, dry nitrogen gas can be used as the fluid sent into the chamber.

[0009]

Embodiments of the present invention will be described below in detail with reference to the drawings. Embodiment 1 of the present invention will be described with reference to FIGS. The same members as those in FIG. 5 described in the related art are denoted by the same reference numerals, and redundant description will be omitted. As shown in FIG. 1, a powdery or granular food material 5 which is a dry food material, such as grains such as wheat, buckwheat buckwheat, and brown rice, spices, and beans, is put into a supply hopper-4. A cut-out device 6 is provided at a lower end of the supply hopper-4,
An appropriate amount of the granular food material 5 is continuously cut out from the supply hopper 4 by the cutout device 6 and sent to the inlet side of the chamber 14 disposed below the cutout device 6.

In the first embodiment, a perforated plate 15 is provided in a closed chamber 14 as a porous body for partitioning the inside of the chamber 14 up and down, and drying is performed from below the perforated plate 15 through the holes of the perforated plate 15. By blowing air 18, the particulate food material 5 is lifted, conveyed while being rotated, and irradiated with the electron beam 2 to sterilize the entire surface of the particulate food material 5. is there.

On the upper surface of the chamber 14 on which the electron beam irradiating device 1 is provided, a thin window foil 11 made of titanium or aluminum for partitioning a boundary portion of the electron beam irradiating device 1 on the upper surface, that is, a joint portion is provided. The irradiation port of the electron beam irradiation device 1 is attached to the window foil 11.

In the vicinity of the window foil 11, a chamber 14 is provided.
Is provided with a cool air nozzle 12 for blowing cooling air from the inside of the chamber 14 toward the window foil 11, and the dry air 18 is supplied from outside the chamber 14. Is done. The chamber 14 is a sealed long cylindrical housing, and has an internal perforated plate 15 therein.
By blowing dry air 18 from underneath, the particulate food material 5 is lifted, conveyed while rotating, and irradiated with the electron beam 2 from the electron beam irradiation device 1 provided on the upper part of the window foil 11, to thereby produce the particulate food material. 5 is to be sterilized. The chamber 14 is arranged so as to be gradually lowered along the conveying direction of the granular material 5.

The perforated plate 15 is provided in the chamber 14 so as to be inclined in the longitudinal direction of the chamber 14.
The plate surface has a mesh-shaped opening hole. The above supply hopper
A continuous cutting device 16 is provided on the lower side of 4, and the continuous cutting device 16 continuously cuts the granular food material 5 in the supply hopper 4 into the chamber 14 by a constant amount, A continuous cutting device such as a rotary valve is used. A blower 17 feeds dry air 18 below the perforated plate 15 of the chamber 14.
Is provided on the upstream side in the transport direction of the granular material 5 in the chamber 14. A continuous cutting device 19 such as a rotary valve is provided downstream of the chamber 14 in the conveying direction of the granular material 5, and a continuous cutting device 19 is provided below the continuous cutting device 19. Hopper-2 for storing the sent-out sterilized powdery food material 7
0 is provided. Aseptic air 24 is fed into the hopper 20.

On the other hand, a filter 21 for removing dusts such as dust in the dry air 18 discharged from the chamber 14 is provided on the downstream side wall surface for discharging the dry air from the chamber 14. An ozone removing device 22 for removing ozone generated by electron beam irradiation is provided in a passage exhausted through the filter 21. An activated carbon filter or the like is used. The air purified by removing dust and ozone by the filter 21 and the ozone removing device 22 is supplied to an exhaust fan 23.
Is configured to be discharged outside the system. A vibration feeder 25 is provided on the entrance side (the right side in FIG. 1) in the chamber 14.
Numeral 5 is obtained by diffusing the granular food material 5 cut out from the continuous cutting device 16 while vibrating and supplying it to the perforated plate 15 as a thin layer (single layer).

According to the electron beam sterilizer configured as described above, the granular food material 5 stored in the supply hopper 4 is
A fixed amount is continuously cut out from the continuous cutting device 16 at the lower part of the supply hopper 4, and is dropped onto the vibrating feeder 25 in the chamber 14. The dropped granular food material 5 spreads in a thin layer (single layer) by the vibration of the vibration feeder 25 and is sent to the perforated plate 15 while sliding down the inclined surface of the vibration feeder 25. On the other hand, dry air 18 is sent to the lower side of the chamber 14 by the blower 17.

In this way, in the chamber 14, the powdered and granular food material 5 rises and rotates down the inclined surface of the perforated plate 15 by the dry air 18 blown from below the perforated plate 15, and is irradiated with the electron beam 2. Transported to a location. Then, for example, when the irradiation energy is 30
The electron beam 2 having a relatively low energy of 0 keV or less
Irradiate the powdered and granular food material 5 being conveyed. At this time, the dry air 18 is blown out from the cold air nozzle 12 toward the window foil 11 to cool the window foil 11.

Since the electron beam 2 is irradiated while the food material 5 being transported floats and rotates, the electron beam 2 is uniformly applied to the entire surface of the particle material. After passing through the irradiation position, the sterilized granular material 7 falls from the outlet side (the left side in the figure) and is stored in the hopper 20 through the continuous cutting device 19, and the sterilized air 24 is supplied to the hopper 20. Is constantly being sent in to prevent outside air from entering. Then, the sterilized powdery and granular food material 7 is taken out from the lower portion of the hopper 20,
It is transported to the next aseptic filling process. Dry air 18 in the chamber 14 is filtered by a filter 21 provided on the outlet side.
The dusts are removed by ozone, and the ozone is removed by the ozone removing device 22, and the purified air is discharged out of the system by the exhaust fan 23.

According to this embodiment, the closed chamber
By irradiating the electron beam while floating and rotating the powdered food material 5 in 14, the entire surface of the powdered food material 5 can be uniformly irradiated with the electron beam 2.
Germicidal effect can be further enhanced. Also,
The granular food material 5 is sterilized in the closed chamber 14 and stored in the hopper 20 in an aseptic state.
Can be prevented from being recontaminated. Further, the powdered food material 5 is conveyed and sterilized in the atmosphere of the dry air 18 in the chamber 14, so that the caking phenomena of the powdered food material 5 due to moisture (the powder sticks to the ball due to moisture). Phenomenon) can be suppressed, and a decrease in product quality of the granular food material 5 can be prevented. Furthermore, by using dry nitrogen gas 31 as a fluid for transporting the granular food material 5,
Ozone is not generated by the irradiation of the electron beam 2. For this reason, the installation of the ozone removing device 22 becomes unnecessary.

Next, another embodiment of the present invention will be described with reference to FIG.
This will be described below. The same members as those in FIGS. 1 to 3 described in the first embodiment are denoted by the same reference numerals, and redundant description will be omitted. In the first embodiment, the dry air 18 is used as the fluid to be fed into the chamber 14, and the ozone removing device 22 is provided at the outlet side of the chamber 14.
The dry nitrogen gas 31 is used as a fluid to be sent into the chamber 14, and the ozone removing device 22 is omitted.

As shown in FIG. 4, a dry nitrogen gas 31 is sent by a blower 17 below the perforated plate 15 of the chamber 14. Then, the dry nitrogen gas 31 is applied to the perforated plate 1.
The powdered food 5 is blown up from the opening hole of 5, and is conveyed while floating and rotating, and the electron beam 2 is transferred to the powdered food 5 being conveyed.
Is irradiated. Further, a dry nitrogen gas 31 is externally supplied to the cold air nozzle 12 to cool the window foil 11. The dry nitrogen gas 31 used for the conveyance is discharged out of the system by the blower 23 after dust is removed by the filter 21. Other configurations are the same as in the first embodiment.

According to the electron beam sterilizer configured as described above, when the granular food material 5 supplied into the chamber 14 is sent from the vibration feeder 25 to the perforated plate 15,
The dry nitrogen gas 31 is blown up from below the perforated plate 15 to lift and rotate the granular food material 5 and convey the inclined surface to the downstream side. Then, since the electron beam 2 is uniformly applied to the whole surface of the granular food material 5 toward the granular food material 5 being conveyed, the sterilizing effect can be enhanced.

As described above, according to the second embodiment, since the dry nitrogen gas 31 is used as the fluid for transporting the granular food material 5, no ozone is generated by the irradiation of the electron beam 2. For this reason, it becomes unnecessary to install an ozone removing device. In addition, the same operation and effect as those of the first embodiment can be obtained.

The present invention is not limited to the above-described embodiment. For example, as long as it can be sterilized by the electron beam 2, the present invention is not limited to the powdered food material 5, but can be applied to various powdered materials. Can be applied. Further, the porous body only needs to have a large number of holes, and is not limited to the porous plate 15, but may be a mesh-like one. Further, as the fluid, dry air,
Alternatively, it goes without saying that not only the dry nitrogen gas 31 but also various fluids can be used.

[0024]

As described above, according to the electron beam sterilizer according to the present invention, the direction of the powdered or granular food material is changed by irradiating the powdered or granular material with the electron beam while moving the powdered or granular material in the closed chamber by the fluid pressure. Since the entire surface can be uniformly irradiated with the electron beam by changing, the sterilizing effect can be further enhanced. In addition, by performing the electron beam irradiation, it is sterilized in the closed chamber and stored in the hopper in an aseptic state, so that re-contamination can be prevented. Furthermore, by carrying out the sterilization treatment by transporting the granular food material in an atmosphere of dry air in the chamber, the caking phenomenon due to the moisture of the granular material (the phenomenon of the powder sticking together due to the moisture) is suppressed. In addition, deterioration of product quality can be prevented. Furthermore, by using dry nitrogen gas as the fluid for transporting the granular material, ozone is not generated by electron beam irradiation. For this reason, it becomes unnecessary to install an ozone removing device.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing an electron beam sterilizer according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view taken along line II-II of FIG.

FIG. 3 is a perspective view of a perforated plate according to the present invention.

FIG. 4 is a conceptual diagram showing an electron beam sterilizer according to another embodiment of the present invention.

FIG. 5 is a conceptual diagram showing a conventional electron beam sterilizer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electron beam irradiation device 2 Electron beam 4 Supply hopper 5 Granular food material (Granular material) 6 Cutting device 7 Granular food material 11 Window foil 14 Chamber 15 Perforated plate (Porous body) 16 Continuous cutting device 17 Blower 18 Dry air (fluid) 19 Continuous cut-out device 20 Hopper 21 Filter 22 Ozone removal device 23 Exhaust air 24 Sterile air 25 Vibration feeder 31 Dry nitrogen gas (fluid)

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) G21K 5/04 G21K 5/04 E 5/10 5/10 FCF term (reference) 3F047 BA01 4B021 LA44 LP10 LT01 LW07 LW09 MC01 4C058 BB06 KK02 KK04 KK05 KK06 KK21

Claims (6)

[Claims] 1. A closed chamber, a porous body provided at an inclination in the chamber and supplied with powdery material on an upper surface, and a porous material fed into a lower portion of the porous material, and A fluid for conveying the supplied granular material along the inclined surface of the porous body by a fluid pressure ejected from a hole of the porous body,
An electron beam sterilizer, comprising: an electron beam irradiator that irradiates an electron beam to a powdery or granular material conveyed on the upper surface side of the porous body. 2. A closed chamber, a vibrating feeder for vibrating and dispersing the powder supplied in the chamber, and a slant so as to partition the inside of the chamber up and down. The porous body provided with the granular material sent from the vibrating feeder onto the plate surface, and the granular material delivered below the porous body and supplied to the upper surface of the porous body are formed into pores of the porous body. Fluid to be transported along the inclined surface of the porous body by the fluid pressure ejected from the chamber, a continuous cutting device provided at a supply port of the granular material to the chamber, and a discharge port of the granular material from the chamber And an electron beam irradiation device provided in the chamber and irradiating the moving granular material with an electron beam while floating on the upper surface of the perforated plate. Electron beam sterilizer. 3. The method according to claim 1, further comprising the step of:
3. The electron beam sterilizer according to claim 1, further comprising an ozone removing device for removing ozone generated in the inside. 4. The method according to claim 1, wherein the chamber and the electron beam irradiation device are directly connected via a window foil provided at a boundary portion.
The electron beam sterilizer according to any one of claims 1 to 3, wherein a fluid ejection nozzle for cooling the window foil is provided in the chamber. 5. The electron beam sterilizer according to claim 1, wherein the fluid sent into the chamber is air. 6. The method according to claim 1, wherein the fluid fed into the chamber is dry nitrogen gas.
The electron beam sterilizer according to any one of the above.