JP2766211B2 - UV sterilizer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultraviolet sterilizer for sterilizing an object to be sterilized such as raw meat.

[0002]

2. Description of the Related Art In recent years, in a wholesale factory for producing raw meat such as livestock meat or animal meat, in order to save labor at the retail stage, there is a tendency that raw meat is divided into appropriate sizes and then supplied to the retail stage. In addition, in such a production wholesale factory, usually, a small portion of raw meat is vacuum-packaged with a transparent wrap film and then sterilized using an ultraviolet sterilizer.

As described in Japanese Utility Model Laid-Open Publication No. 1-2604 or Japanese Utility Model Laid-Open Publication No. 1-94208, for example, a conventional general ultraviolet sterilizing apparatus includes an ultraviolet irradiation chamber and vacuum-packed raw meat (hereinafter referred to as “packaging”). And a drive roller conveyor for carrying meat from the carry-in port of the ultraviolet irradiation chamber and carrying it out of the carry-out port. Ultraviolet lamps are installed in the side and top surfaces of the ultraviolet sterilizing chamber and between the rollers of the driving roller conveyor, and the ultraviolet light emitted from the ultraviolet lamp sterilizes the surface of the conveyed raw meat. ing.

[0004]

The temperature of the workplace at the production and wholesale factory is adjusted to 18 ° C. or less in order to suppress the propagation of various bacteria, and the temperature of the packaged meat is adjusted to about 4 ° C. Under such a low-temperature environment, the fats and oils of the raw meat are solidified. However, since raw meat containing oils and fats is always handled, even if the raw meats are vacuum-packaged, the oils and fats gradually adhere to the roller surface of the drive roller conveyor in the ultraviolet sterilizer.

In the above-mentioned conventional ultraviolet sterilizer, since the roller surface of the drive roller conveyor has a smooth cylindrical surface, if oil or fat adheres to the roller surface, slippage occurs between the packaging meat and the roller. The package meat may stay on the drive roller conveyor, and this tendency is more remarkable as the weight of the package meat is smaller. In addition, the temperature inside the ultraviolet irradiation chamber is higher than the ambient temperature due to the heat from the ultraviolet lamp, and the viscosity of the oils and fats attached to the rollers is reduced. Larger than outside the irradiation room.

[0006] When the packaged meat stays in the ultraviolet irradiation chamber, the surface temperature of the raw meat rises as the protein is denatured by the heat from the ultraviolet lamp, and the meat becomes discolored and its commercial value is reduced. Or many separate. In addition, since the wrap film, which is a packaging material, is also discolored by heat, the commercial value of raw meat in a packaged state is reduced.

For this reason, it is conceivable to provide a large number of projections having a needle-like cross section extending in the outer peripheral axis direction on the outer peripheral surface of each roller of the drive roller conveyor. Holes may open. In addition, if the intervals between the projections are short and many, it is troublesome to remove the deposits deposited between the projections, and it is unsanitary (Japanese Utility Model Laid-Open No. 5-82930).

Here, the wrap film is a single-layer or multi-layer packaging film. When utilizing contraction and adhesion by heat, the stretched film is used, and when utilizing adhesion by static electricity or adhesion, the unstretched film is used. As the form of the film, the bag-like film is preferably used for automation of the lapping operation by a machine, and the bag-like film or the roll-wound film is used for the manual lapping operation.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an ultraviolet sterilizer having a drive roller conveyor capable of preventing accumulation of an object to be sterilized such as packaged meat. is there.

[0010]

In order to achieve the above object, the present invention provides an ultraviolet irradiation chamber in which a predetermined ultraviolet irradiation area is formed, and an object to be sterilized is conveyed across the ultraviolet irradiation area. In an ultraviolet sterilizer having a driving roller conveyor provided so as to penetrate an ultraviolet irradiation chamber, a roller of a driving roller conveyor, a so-called driving roller, a roller having a plurality of plate-shaped protrusions protruding from an outer peripheral surface. It is characterized by being used. The plate-like projections extend along the longitudinal axis of the roller and are arranged on the outer peripheral surface of the roller at equal intervals in the circumferential direction. Further, the center-to-center arc length (arc length L in FIG. 3) of the adjacent plate-like projections along the roller surface is set to 15 mm to 90 mm.

It is effective that the protruding height of the plate-like projections with respect to the outer peripheral surface of the roller of the driving roller conveyor is 1 mm to 2 mm, and the number of the plate-like projections provided on the roller is two to four.
It should be a book.

Further, since the plate-like projection is made of metal and has a surface finished, high reflectance is expected.

Further, by chamfering the corners of the plate-like projections, it is expected that the film of the packaging meat is prevented from being broken.

[0014] Further, in order to prevent ultraviolet rays from leaking from the carry-in portion and carry-out portion of the object to be sterilized in the ultraviolet irradiation room, sub-chambers are provided adjacent to the carry-in portion and the carry-out portion of the ultraviolet irradiation room, respectively. A drive roller conveyor may extend into each of the sub-chambers. In this case, as a roller of the drive roller conveyor located in the sub-chamber, instead of a roller with a projection,
A roller having a polygonal prism shape having a cross section of a regular pentagon or a regular octagon can also be used.

When the sub-chamber is provided, it is desirable to install a light-shielding curtain at each of the carry-in portion and the carry-out portion of the ultraviolet irradiation chamber in order to further suppress the leakage of ultraviolet rays.

[0016]

As described above, by using a roller with a plate-like projection or a polygonal pillar-shaped roller as a roller of the drive roller conveyor, the plate-like projection or the polygonal pillar-shaped roller is formed on the surface of an object to be sterilized such as packaging meat. The corners of the rollers bite into each other to prevent slippage, and the object to be sterilized can be pushed out in the transport direction.

In the case of rollers having a polygonal column shape, the up-and-down movement of the packaged meat is made possible, and the frequency of irradiation of ultraviolet rays from multiple directions on the uneven meat surface increases the sterilization of the surface.

In a roller having a plate-like projection,
When the projection height of the plate-like projections is 1 mm to 2 mm and the number of the plate-like projections is 2 to 4, this pushing action is effectively exerted.

The distance between the plate-like protrusions arranged at equal intervals in the circumferential direction of the roller, that is, the length of the center-to-center arc along the roller surface connecting the centers of the adjacent plate-like protrusions is preferably 15 mm to 90 mm. If the center-to-center arc length exceeds 90 mm, the extruding action is small when the weight of the packaged meat is small, and the package meat tends to stay. The center-to-center arc length is 15 m.
If it is less than m, it takes time to remove the deposits accumulated between the plate-like projections, and it is unsanitary. More preferably, the center-to-center arc length is 25 mm to 76 mm in view of the balance between the extruding action and the removal of accumulated deposits. In the drive roller conveyor, since any two of the plate-like projections of the roller appear on the conveying surface, an efficient pushing action can be expected, and the height of the plate-like projection required for the action is 1 mm to 2 mm. Got enough. The size of the center-to-center arc length is particularly effective for a roller having an outer diameter of 48 mm, but the roller diameter is not limited to 48 mm.

Further, in the case where the plate-like projections are made of metal and surface-finished, ultraviolet rays can be irregularly reflected with the rotation of the rollers.

[0021]

1 and 2 show an ultraviolet sterilizer 1 according to the present invention for sterilizing raw meat (packed meat) M vacuum-packaged.
0 shows one embodiment. In these figures, reference numeral 12 indicates its housing. The housing 12 has a horizontally elongated box structure, in which a drive roller conveyor 14 is disposed. The drive roller conveyor 14 extends from one end plate 16 to the other end plate 18 of the housing 12 along the longitudinal direction of the housing 12.

The drive roller conveyor 14 includes the housing 1
2 and a pair of side frames 20, 21 extending in the longitudinal direction of the housing 12, and a number of rollers 2 rotatably supported between the side frames 20, 21.
2 and 24, and driving means for rotating these rollers 22 and 24. Various types of driving means are conceivable. In the illustrated embodiment, a driving force from an electric motor 26 serving as a driving source is transmitted to each of the rollers 22 and 24 by an endless chain 28, and this type is rotated. Has been adopted. The rollers 22, 24 used in the drive roller conveyor 14
Has a special shape, not a simple cylindrical shape,
This will be described later.

The space inside the housing 12 that is located above the conveying surface of the driving roller conveyor 14 (the surface defined by the upper common tangent line of the rollers 22 and 24) is the longitudinal direction of the housing 12. Are divided into three areas. The central part of the space functions as an ultraviolet irradiation chamber 30 for irradiating the packaging meat M conveyed by the drive roller conveyor 14 with ultraviolet light to sterilize the package meat M, and the space parts on both sides thereof are separated from the ultraviolet irradiation chamber 30 respectively. It functions as sub-chambers 32 and 34 for preventing leakage of ultraviolet rays.

A plurality of ultraviolet lamps 36 are arranged inside the ultraviolet irradiation chamber 30 so that the packaging meat M conveyed by the driving roller conveyor 14 can be irradiated with ultraviolet light. In the illustrated embodiment, the ultraviolet lamp 36 is a straight tube, and the upper plate 38 and the side plates 40,
41 are arranged along the inner surface. The ultraviolet lamp 36 is also arranged between the adjacent rollers 24 so as to enable ultraviolet irradiation from below. In FIG.
Is a reflection plate, which reflects the ultraviolet rays radiated outside the housing 12 inward to increase the irradiation rate to the package meat M. The size of the ultraviolet irradiation area surrounded by the ultraviolet lamps 36, the amount of ultraviolet irradiation of each ultraviolet lamp 36, and the wavelength of the ultraviolet light in this manner are determined based on the transport speed of the driving roller conveyor 14 and the handling of the ultraviolet light. It is appropriately determined according to the required irradiation dose and the like for the packaged meat M to be prepared.

At the boundary between the ultraviolet irradiation chamber 30 and the sub-chamber 32 (load-in section) and at the boundary between the ultraviolet irradiation chamber 30 and the sub-chamber 34 (export section), ultraviolet rays from the ultraviolet irradiation chamber 30 are provided. In order to prevent leakage of light, a light-shielding curtain 44 for blocking ultraviolet rays is attached. This shading curtain 44
Is formed by hanging a plurality of strips like a curtain so as not to hinder the movement of the packaged meat M from the sub chamber 32 to the ultraviolet irradiation chamber 30 or from the ultraviolet irradiation chamber 30 to the sub chamber 34. The end plates 16, 18 of the housing 12 adjacent to the sub-chambers 32, 34 respectively have an entrance 46 for the packaged meat M.
And a carry-out port 48 are formed, and the carry-in port 46 and the carry-out port 48 are also provided with a curtain-like light-shielding curtain 50 similar to the light-shielding curtain 44.

FIG. 3 is an enlarged view showing the rollers 24 of the driving roller conveyor 14 located in the ultraviolet irradiation chamber 30. As can be understood from this figure, two or more, in the illustrated embodiment, four plate-like projections 52 are provided on the outer peripheral surface of each roller 24.
Is provided. These plate-like projections 52 are
The roller 24 extends over the entire length of the roller 24 in parallel with the longitudinal axis of the roller 4 and is arranged at equal intervals in the circumferential direction. The outermost surface 54 of the plate-like projection 52 is a substantially flat surface. The side surface 56 of the plate-like projection 52 is substantially perpendicular to the outermost surface 54.
Is preferably chamfered so as not to damage the wrap film (not shown) of the package meat M. Further, like the roller 24, the plate-like projection 52 is made of stainless steel (SUS304), and is preferably surface-finished so as to reflect ultraviolet rays with high reflectance. As a means for forming the plate-like projections 52, a method is preferable in which a groove extending in the longitudinal direction is formed on the outer peripheral surface of a normal cylindrical roller, and a plate-like member is fitted and joined to the groove.

On the other hand, the roller 22 of the driving roller conveyor 14 located in the sub-chambers 32 and 34 has a polygonal column shape, and a cross section perpendicular to the longitudinal axis of the roller 22 has a regular polygonal shape, preferably a regular pentagonal shape. It is a regular hexagon, regular heptagon or regular octagon. As clearly shown in FIG. 4, in this embodiment, the rollers 22 in the sub chambers 32 and 34 have a hexagonal column shape. The adjacent surface 58 and surface 5 of the roller 22
8 is chamfered so as not to damage the wrap film of the package meat M. The rollers 22 in the sub-chambers 32 and 34 are attached to the side frames 20 and 21 such that the circumferential directions thereof are alternately different. That is, as shown in FIG.
When one of the surfaces 58 is at the uppermost position, the roller 22b adjacent thereto is positioned so that the corner 60 is at the uppermost position.
Preferably, a roller 22 is provided.

Next, with respect to such a configuration, the operation of the ultraviolet sterilizer 10 of the present invention will be described in detail.

First, when a switch (not shown) is turned on to start the ultraviolet sterilizer 10, the driving roller conveyor 1 is turned on.
4 drives all the rollers 22, 24 in the same direction (the direction of the arrow in FIGS. 3 and 4),
The ultraviolet lamp 36 in the ultraviolet irradiation chamber 30 is turned on. In this state, the packaged meat M in the chilled state is
2 through a carry-in port 46 formed in one end plate 16 of the sub-chamber 3.
2, the packaged meat M is conveyed toward the ultraviolet irradiation chamber 30 by the hexagonal column-shaped roller 22 which is driven to rotate.

At this time, since the roller 22 has a hexagonal column shape, when it is rotated, its corner 60 pushes up the packaging meat M and bites into the packaging meat M appropriately. When the roller 22 is further rotated, the package meat M is pushed out in the transport direction. Therefore, even if some fats and oils adhere to the outer peripheral surface of the roller 22, slippage between the package meat M and the roller 22 is suppressed, and the conveyance can be performed. More specifically, the circumferential direction of the adjacent rollers 22 is staggered in the same direction as the transport direction of the package meat, so that the package meat M is prevented from jumping and repelling on the rollers 22.

Although the cross-sectional shape of the roller 22 is not limited to the hexagonal shape as described above, if the cross-sectional shape of the roller 22 is square or triangular, for example, in the case of the packaging meat M which is relatively small and divided into about 100 g, The movement in the up-down direction is large, and may jump and repel on the roller 22 and fall off the conveyance surface. Further, the roller 22 whose cross-sectional shape exceeds the octagon
In this case, since the angle of the corner becomes large, the amount of bite into the packaged meat M is reduced, and a desired pushing force is not obtained, so that there is a possibility of stagnation. Therefore, the cross-sectional shape of the roller 22 is
It is preferably a regular pentagon, regular hexagon, regular heptagon or regular octagon.

In this manner, the packaged meat M is transported in the sub-chamber 32, and is then transported through the light shielding curtain 44 into the ultraviolet irradiation chamber 30. In the ultraviolet irradiation chamber 30,
The packaged meat M receives the ultraviolet rays from the ultraviolet lamp 36, and the surface of the raw meat is sterilized. In the ultraviolet irradiation chamber 30, the plate-shaped projections 52 of the rollers 24 bite into the wrapped meat M in a chilled state, and push the wrapped meat M in the transport direction. Therefore, as in the case of the hexagonal-pillar-shaped roller 22, even if some fats and oils adhere to the surface of the roller 24, the package meat M is transported. However, the surface of the roller 24 provided with the plate-like projections 52 can be regarded as an uneven surface, and the slip prevention effect is higher than that of the hexagonal columnar roller 22, so that the package meat M is transported reliably.

In this embodiment, since the plate-like projection 52 is made of stainless steel and has a smooth surface finish, the ultraviolet lamp 36, especially the ultraviolet light disposed between the rollers 24, is rotated with the rotation of the roller 24. Ultraviolet rays from the lamp 36 are irregularly reflected, so that it is possible to reduce uneven irradiation of the package meat M.

The dimensions of each part of the plate-like projection 52 are appropriately determined according to various conditions such as the chilled state of the package meat M, the internal temperature of the ultraviolet sterilizer 10, and the thickness of the wrap film. For the SUS304 roller 24 having an outer diameter D of 48 mm, the protruding height h of the plate-shaped projection 52 is set to 1 mm to 2 mm, the width W is set to about 4 mm to 6 mm, and the corner between the surface 54 and the surface 56 is formed. 0.5mm chamfer
(Cut to 45 degrees at a position driven by 0.5 mm). By the end of the equipment's useful life of seven years, the chamfering of this corner due to abrasion has been reduced to 1 at the time of delivery inspection.
It may be about a percentage larger. Experiments have shown that under this dimensional condition, even about 100 g of packaged meat M, which has been stagnated by a conventional cylindrical roller, is conveyed without stagnating. Further, under the dimensional conditions of the protruding height and width of the surface-finished plate-like projection 52, there is also an effect that the ultraviolet rays are more likely to be irregularly reflected with the rotation of the plate-like projection.

In the illustrated embodiment, the number of the plate-like projections 52 is four, but the number is not particularly limited.
However, it should be noted that if the number is five or more, oils and fats easily adhere and accumulate between the plate-like projections 52, and it takes time for cleaning.

The packaged meat M transported in the ultraviolet irradiation chamber 30
Is sterilized by irradiation with ultraviolet light, passes through the light-shielding curtain 46, and is introduced into the other sub-chamber 34. In the sub-chamber 34, similarly to the sub-chamber 32, the package meat M is transported to a position short of the end plate 18 by the hexagonal column-shaped roller 22. When the package meat M reaches the end of the drive roller conveyor 14 on the side of the end plate 18 in this way, the package meat M is taken out from the carry-out port 48 formed in the end plate 18 and the sterilization operation is completed.

Although the preferred embodiments of the present invention have been described in detail above, it is needless to say that the present invention is not limited to the above embodiments.

For example, although the hexagonal column-shaped roller 22 is used as the roller in the sub-chambers 32 and 34, a roller with a plate-like projection similar to the roller 24 in the ultraviolet irradiation chamber 30 may be used.

In the above embodiment, the ultraviolet irradiation chamber 30
Although all of the rollers inside are rollers 24 with plate-like protrusions, plate-like protrusions 52 may be provided only on some of the rollers. For example, a roller with a plate-like projection may be arranged only in a portion where the retention is likely to occur. In this case, in order to sufficiently exhibit the stagnation prevention effect, it is desirable to arrange at least four continuous rollers with plate-like projections.

Further, the rollers 22, 24 and the plate-like projections 52
The material of is not limited to those of the above embodiment, and
In order to increase the ultraviolet reflectance of the plate-like projections, it is also possible to use means such as surface plating.

The material to be sterilized by the ultraviolet sterilizer according to the present invention is not limited to raw meat, but may be processed meat containing oils and fats, marine products including oils and fats, processed fishery products, and dried fish. Good.

[0042]

As described above, according to the present invention, the roller of the drive roller conveyor in the ultraviolet sterilizer has a plate-like projection or a polygonal column shape. Objects to be sterilized, such as raw meat, can be transported without stagnation. Therefore, problems such as discoloration of the object to be sterilized that occurs when the object to be sterilized stays in the ultraviolet irradiation chamber are solved.

Although the plate-like projections provided on the roller make a line contact with the object to be sterilized instantaneously, they are substantially in surface contact, so that the packaging material of the object to be sterilized may be damaged. Nor.

Further, since there is an effect of preventing stagnation even if the number of plate-like projections is four or less, cleaning of the roller can be performed extremely easily if the number of plate-like projections is two to four.

Further, when the plate-like projection is made of metal,
Since the ultraviolet rays from the ultraviolet lamp are irregularly reflected, irradiation unevenness can be reduced and sterilization efficiency can be increased. This effect is particularly remarkable when the ultraviolet lamp is disposed below the conveying surface of the drive roller conveyor.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view along an conveyance direction showing an embodiment of an ultraviolet sterilizer according to the present invention.

FIG. 2 is a schematic sectional view taken along line II-II of FIG.

FIG. 3 is an enlarged sectional view showing a shape of a driving roller conveyor, particularly a roller, in an ultraviolet irradiation chamber of the ultraviolet sterilizer of FIG.

FIG. 4 is an enlarged sectional view showing a shape of a driving roller conveyor, particularly a roller, in a sub-chamber of the ultraviolet sterilizer of FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... ultraviolet sterilizer, 12 ... housing, 14 ... drive roller conveyor, 22 ... roller in subchamber, 24 ... roller in ultraviolet irradiation chamber, 30 ... ultraviolet irradiation chamber, 36 ... ultraviolet lamp, 52 ... plate-shaped projection.

Claims (8)

(57) [Claims] 1. An ultraviolet irradiation chamber in which a predetermined ultraviolet irradiation area is formed, and a drive roller conveyor provided through the ultraviolet irradiation chamber so that an object to be sterilized is conveyed across the ultraviolet irradiation area. In the ultraviolet sterilization apparatus comprising: the drive roller conveyor is provided with a roller driven by a drive source and having a plurality of plate-shaped protrusions protruding on an outer peripheral surface,
The plate-like protrusions extend along the longitudinal axis of the roller and are arranged at equal intervals in the circumferential direction on the outer peripheral surface of the roller, and the center-to-center arc length of the adjacent plate-like protrusions along the roller surface Is 15 mm to 90 mm. 2. The ultraviolet sterilizer according to claim 1, wherein a height of the plate-like projection from the outer peripheral surface of the roller is 1 mm to 2 mm. 3. The ultraviolet sterilizer according to claim 1, wherein two to four plate-like projections are provided on the roller. 4. The ultraviolet irradiation chamber is disposed adjacent to the carry-in section and the carry-out section of the ultraviolet irradiation chamber to prevent ultraviolet leakage from the carry-in section and the carry-out section of the object to be sterilized in the ultraviolet irradiation chamber. The ultraviolet sterilizer according to any one of claims 1 to 3, further comprising a subchamber, wherein the drive roller conveyor extends to each of the subchambers. 5. The driving roller conveyor located in the sub-chamber includes a polygonal pillar-shaped roller having a regular pentagonal to regular octagonal cross-section instead of the roller having the plate-like projection. The ultraviolet sterilizer according to claim 4, wherein: 6. The ultraviolet sterilizer according to claim 4, wherein a light-shielding curtain composed of a plurality of belts is disposed at each of the carry-out portion and the carry-out portion of the ultraviolet irradiation chamber. 7. The object to be sterilized is raw meat vacuum-packaged with a wrap film.
The ultraviolet sterilizer according to any one of items 6 to 6. 8. The object to be sterilized is processed meat containing fats and oils, fresh fish containing fats and oils and processed fishery products containing fats and oils, and is vacuum-packaged with a wrap film. 7. The ultraviolet sterilizer according to any one of items 1 to 6.