JP2004262528A - Method and device for inert gas substitution - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform effective inert gas substitution up to a corner part and a shoulder part inside a container with a simple configuration without disposing a complicated structural body in an upper part of the container, to obtain the high gas substitution ratio even in a high-speed line, and to reduce possible mixture of foreign matter in the container. <P>SOLUTION: A cover plate 9 is disposed above a carrying passage to carry a container to a sealing part from a filling device with a predetermined space from the container under carriage, substitution gas nozzle bodies 2 having slit-shaped nozzles 12 to horizontally blow inert gas above an opening part of the container in the direction of the container carrying center line are disposed on both sides of the carrying passage, and inert gas is blown from the slit-shaped nozzles 12 facing each other on both sides of the carrying passage along a lower side of the cover plate, and collided with each other in a vicinity of the container carrying center line to form a flow toward a head space of the container. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method and an apparatus for purging gas in a headspace portion of a container.
[0002]
[Prior art]
2. Description of the Related Art Various means for replacing oxygen in a head space portion of a container with an inert gas such as nitrogen gas and sealing the same in order to prevent deterioration of the quality of the contents in the production of canned foods and other packaged foods have been proposed. For example, in the case of canning, a method in which an inert gas is blown directly or through a filter from above and from the side of the can body in a can body conveying path to the winding device to replace the can body (for example, see Patent Documents 1 to 4), A method in which an inert gas is blown into the container obliquely from above with respect to the horizontal direction, and at the same time or immediately before, the air inside the container is suctioned from obliquely above and replaced (see Patent Document 5) In the method of blowing an inert gas immediately before the can and the lid are fitted, that is, in the “undercover gassing (nozzle gassing with a gas turret) method”, an inert gas is filled in the gap between the can lid and the can body. (See Patent Documents 6 and 7). In addition, as a gas replacement method for cup-packed foods, there is a method in which the lid is sucked and held and the inert gas is blown from both sides toward the gap between the lid and the container (Patent Document 8) or an inert gas outlet is provided. A plate has been proposed in which an inert gas is blown into a container head space by providing a plate close to the upper surface of the container so as to cover the upper portion of the container opening (Patent Document 9).
[0003]
[Patent Document 1]
JP 2002-46709 A [Patent Document 2]
JP-A-63-125118 [Patent Document 3]
Japanese Utility Model Publication No. 50-16816 [Patent Document 4]
JP 2001-58609 A [Patent Document 5]
JP-A-11-157507 [Patent Document 6]
Japanese Patent Publication No. 2-18057 [Patent Document 7]
JP-A-3-56217 [Patent Document 8]
Japanese Utility Model Publication No. 7-39766 [Patent Document 9]
Japanese Patent Application Laid-Open No. Sho 62-182015
[Problems to be solved by the invention]
Each of the conventional methods proposed above has advantages and disadvantages.However, the method of blowing an inert gas from the side or obliquely upward of the container transport path requires the use of an inert gas since the head space is depressed from the container opening end. Has the drawback that the gas is not sufficiently blown into the head space and gas replacement in the head space is not sufficiently achieved. In particular, air was easily trapped at the corner between the liquid level in the container and the wall of the container body, which was a hindrance to increasing the replacement efficiency. And, in the case of a container having a shoulder portion, gas cannot be replaced in the shoulder portion by this method, so that the method cannot be applied to gas replacement of such a container. The method of arranging an inert gas nozzle directly above the container transport path and blowing the inert gas into the container requires disposing a complicated structure such as a nozzle body for blowing the inert gas into the upper part of the container. In addition, there is a problem that steam and splashed liquid from the filling contents adhere to these structures and may fall into the container, which makes maintenance difficult. Further, in the case of undercover gassing performed by a seamer, gas replacement can be performed only in an instant when the can body and the lid are fitted, so that sufficient gas replacement is achieved particularly in recent high-speed seamers. It is difficult. Further, the conventional gas replacement method has a problem that even when the gas replacement of the container head space temporarily obtains a high replacement rate, external air is caught by the time of sealing, thereby lowering the replacement rate at the time of sealing. Existing.
[0005]
The present invention provides a method for performing gas replacement in the head space of a container and / or a lid when the container is sealed (hereinafter, the container and the lid are simply referred to as a “container” unless the container and the lid are separately listed). With no simple structure, inert gas can be effectively replaced even in corners and shoulders where gas replacement inside the container is difficult with a simple configuration, and a high gas replacement rate can be achieved even in high-speed lines. Provided is a method and an apparatus for replacing an inert gas in a container which can be obtained, is free from the possibility of foreign matter being mixed in the container, is easy to maintain, can easily maintain sterility, and can be applied to aseptic filling. The purpose is to:
[0006]
[Means for Solving the Problems]
The inert gas replacement method of the present invention that solves the above-mentioned problem is that, in the inert gas replacement packaging line, at least the upper part of the container and / or the container being transported from both sides below the cover plate of the lid transport path and / or By blowing the inert gas toward the center line in the transport direction above the lid, an inert gas flow toward the head space of the container and / or the lid being transported is formed, and the inert gas blown into the head space is formed. Convection from the center in the container transport direction to both sides to replace the inert gas in the container head space.
[0007]
The inert gas replacement is desirably performed in a transport path from the content filling device to the sealing section. The flow toward the head space of the container may be caused by the collision of the inert gas flow blown from both sides near the center line of the transfer path, or the flow of the inert gas blown from both sides near the center line of the transfer path. Can be formed by colliding with a shielding plate provided along. Then, a tunnel is formed by covering the container transfer path with a semi-enclosed cover, and an inert gas is blown from a side toward the vicinity of the container opening being transferred into the tunnel at a substantially uniform velocity distribution. By keeping the inside of the tunnel in a low oxygen atmosphere, the inflow of outside air into the tunnel can be prevented, and the gas can be sealed while maintaining a high gas replacement rate.
[0008]
Further, in the inert gas replacement device of the present invention, in the inert gas replacement packaging line, the cover plate is disposed above the transfer path for transferring the container or the cover with a predetermined gap from the container or the cover being transferred. Along with, a replacement gas nozzle body having a slit for blowing an inert gas in the direction of the transport center line of the container or the lid is disposed on both sides of the transport path, and is opposed from both sides of the transport path along the lower surface of the cover plate from the slit. The inert gas is blown in the direction of the transport center line of the container or the lid.
[0009]
It is desirable that the inert gas replacement device is disposed in a transport path from the content filling device to the sealing section. As means for forming a flow toward the head space of the container, an inert gas flow blown from both sides is caused to collide near the center line of the conveyance path, or is formed along the center line of the container conveyance path at the center of the lower surface of the cover plate. It is desirable to employ any of the means for providing a shield plate extending to collide with the shield plate. And, in order to prevent the outside air from being caught in the container, an atmosphere gas nozzle body that blows out an inert gas from the side toward the transfer path is arranged along the can transfer path below the replacement gas nozzle body, It is desirable to arrange a porous diffuser tube inside the nozzle body.
[0010]
The “head space” in the above description is not limited to the space after filling the contents of the container, but also means the space of the container or the lid. The term “above the container and / or the lid” or “above the transport path” means above the opening side of the container or the lid. Similarly, the terms “below the cover plate” and “the lower surface of the cover plate” mean the side of the cover plate facing the opening of the container or the lid. Further, “both sides of the transport path” includes “both sides in the transport area”. The “container” is not limited to a can, but includes a plastic bottle, a cup, a tray, a bag, a tube, and the like.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the embodiment shown in FIG.
This embodiment shows a case where the present invention is applied to a can transport line between a filer and a seamer in a canned beverage production line. As shown in FIG. 2, a can body 20 filled with contents is filled with a filler by a transport conveyor 23. The gas in the head space of the can body which is conveyed and sent to the seamer 25 is replaced. In the present embodiment, a case is shown in which a low oxygen atmosphere control tunnel 30 for maintaining the container transport path in a low oxygen atmosphere is disposed following the inert gas replacement apparatus 1. Can be arranged until immediately before the Cima. In FIG. 2, reference numeral 31 denotes a can turret, 32 denotes a discharge turret, and 33 denotes a discharge conveyor. In the present embodiment, an inert gas nozzle body 34 having the same configuration as an atmosphere gas nozzle body described later is arranged facing the lid transporting section of the candy turret 31, and the lid is closed to the intake portion where the lid 24 covers the can body. By passing through the low oxygen concentration atmosphere, oxygen is prevented from being introduced by the lid when the can body is sealed.
[0012]
FIG. 1 is a cross-sectional view taken along the line AA in FIG. 2 and shows a cross-sectional view of the inert gas replacement device 1 of the present embodiment. The inert gas replacement device 1 of the present embodiment is constituted by a combination of an atmosphere gas nozzle body 2 and a replacement gas nozzle body 3. The atmosphere gas nozzle body 2 extends along the conveying path of the can over a range of at least 20 mm or more, desirably at least 40 mm or more above the opening and below the opening of the can of the can body 20 being conveyed as shown in the figure. They are arranged to blow out inert gas from both sides. The atmosphere gas nozzle bodies 2 and 2 are each formed of a rectangular parallelepiped frame body, three sides of which are closed, and a side plate facing the can transport path is formed of a nozzle plate 5 having a slit or a hole. The semi-closed tunnel 10 is formed by covering the ceiling portions of the atmosphere gas nozzle bodies 2 and 2 on both sides with a cover plate 9 which constitutes a part of the replacement gas nozzle body described later.
[0013]
Since the nozzle bodies 2 and 2 are elongated along the can conveyance path, if the nozzle body is directly supplied from the inert gas supply source via a pipe, the inert gas concentration inside the nozzle body becomes non-uniform, and the nozzle plate 5, the flow velocity distribution of the inert gas blown into the tunnel 10 becomes uneven. As a result, there is a problem that a convection of the inert gas occurs and a phenomenon of entrainment of external air in the tunnel occurs. In the present embodiment, in order to solve the problem, as a means for making the blowing of the inert gas from the nozzle plate surface uniform over the entire longitudinal direction of the nozzle body, a porous gas is provided inside the atmosphere gas nozzle body 2. The air diffuser 6 is arranged to have a double nozzle structure. The porous diffuser tube 6 is a tube made of a material having a void such as a sponge, and the material is not particularly limited, but can be favorably formed by a sintered pipe. By supplying the inert gas into the inside of the nozzle body through the minute gap of the air diffuser, it is possible to perform uniform blowing over the entire length in the longitudinal direction even with an elongated nozzle body. In the figure, reference numeral 7 denotes a socket for connecting an inert gas supply pipe to the air diffuser 6, which is provided at the center in the longitudinal direction of the air diffuser.
[0014]
The replacement gas nozzle body 2 has a rectangular gas chamber 11 extending along both sides above the can transfer path, and has a rectangular gas chamber 11 extending along the can transfer direction at the center, and has a lower part of the gas chamber from both sides of the container transfer path. A slit-shaped nozzle 12 that blows out inert gas in a slit shape toward the center in the transport direction is formed. In the present embodiment, the gas chamber 11 is formed by opening the lower end of the nozzle body 13, and the lower end surface of the nozzle body is formed from the opening of the chamber 11. The bottom surface 14 on the conveyance path side is formed shallower than the bottom surface 15 on the opposite side, a step is formed between the bottom surface 14 and the bottom surface 15, and the cover plate 9 is arranged between the bottom surfaces 14 of the nozzle bodies arranged on both sides of the conveyance path. In addition, by disposing a gas guide plate 8 extending at least to the open end or above the inside of the opening of the can body 20 passing through the can transport path on the other bottom surface 15, a slit-shaped nozzle is provided between the gas guide plate 8 and the cover plate 9. 12 are formed. In this embodiment, the gas guide plate 8 extends to about 10 to 30% in the radial direction of the opening of the can to be conveyed, and is bent downward such that the tip 16 is directed inward of the can as shown in the present embodiment. The slant is directed so that the inert gas stream blown out from the slit-shaped nozzle can easily enter the can. Further, the gas guide plate 8 is disposed so that a predetermined gap is formed between the open end 21 of the can body 20 to be conveyed and the lower surface of the gas guide plate, and the lower surface of the gas guide plate 8 extends from the gap to the gas existing in the can. Has a function of guiding the gas to escape to the outside by being pushed by the inert gas supplied to the head space.
[0015]
A shielding plate 19 is provided at the center of the cover plate 9 so as to hang down in the longitudinal direction so as to be located on the center line of the container transport path. Although the shielding plate 19 is not particularly required in the present embodiment, by providing the shielding plate, the inert gas ejected from the slit-shaped nozzles on both sides strikes the shielding plate 19 and causes the inert gas flow. It can be efficiently directed into the can.
[0016]
The configuration of the low oxygen atmosphere control tunnel 30 is substantially the same as the configuration of the semi-closed type tunnel 27 of the inert gas replacement device as shown in FIG. Detailed description for use will be omitted. The low oxygen atmosphere control tunnel 30 is different from the tunnel 27 in that a top plate 35 is formed by a flat plate instead of a gas guide plate at the top of the atmosphere gas nozzle body 2 disposed on both sides of the transport path. Connected to cover the top of the tunnel.
[0017]
The inert gas replacement device of the present embodiment is configured as described above, and during the operation of the line, as indicated by an arrow 27 from the entire surface of the nozzle plate of the atmospheric gas nozzle body 2 toward the container transfer path, as shown by an arrow 27, in the transfer direction in the tunnel. Inert gas is injected across the tunnel, thereby keeping the tunnel in a low oxygen atmosphere. Since the nozzle body 2 has a diffuser pipe 6 formed of a porous material such as a sintered body disposed therein, the inert gas is injected into the nozzle body as a fine jet flow from the entire circumference. Therefore, the inert gas concentration in the nozzle body becomes substantially uniform over the entire length in the axial direction. As a result, the inert gas is blown from the nozzle plate 5 into the tunnel at a substantially uniform flow rate over the axial length. Therefore, the phenomenon of entrainment of air into the tunnel due to the blowing of the inert gas is small, and the inside of the semi-enclosed tunnel 10 can be maintained at a low oxygen concentration.
[0018]
On the other hand, in the replacement gas nozzle bodies 3 on both sides disposed above the atmospheric gas nozzle body 2, the inert gas supplied to the chamber 11 via the inert gas supply pipe 17 passes from the slit nozzle 12 to the center line of the transport path. Is jetted in the form of a slit toward the lower surface of the cover plate 9 and collides near the center line of the transport path, so that the flow becomes downward. Therefore, a downward flow of the inert gas is generated in the tunnel substantially along the center line in the transport direction under the inert gas atmosphere.
[0019]
In this state, the can body 20 filled with the contents is conveyed by the conveyor 21 and passes through the tunnel, so that the downward flow of the inert gas blown out by the replacement gas nozzle body 3 flows along the center line in the conveyance direction. Blows into the headspace of the can, displacing the air present in the headspace. At this time, the inert gas is dripped and blown into the container head space being conveyed so as to traverse the central portion in the traveling direction, as shown by the arrow 28, hits the liquid level 22 and spreads at the corner of the can. As a result, an upward flow is generated, hits the gas guide plate 8, and flows out of the can through the gap between the lower surface of the gas guide plate 8 and the opening edge 21 of the can. The flow rate of the inert gas blown out from the slit nozzle 12 is set to be higher than the flow rate of the inert gas blown out from the nozzle plate 5.
[0020]
Therefore, according to the present invention, according to the conventional gas replacement method, gas replacement can be performed up to the corner between the liquid surface and the container wall portion where air can easily accumulate, and the gas replacement rate can be increased as compared with the related art. Moreover, in the present embodiment, since the atmosphere gas nozzle body having the air diffuser inside is disposed on the side surface of the tunnel, it is possible to prevent air from being trapped inside the tunnel as described above, and to reduce the oxygen content in the tunnel. The can body can be conveyed to the seamer winding position while being maintained in the atmosphere, and can be tightened, and can be sealed while maintaining a high gas replacement ratio. Further, since the inert gas replacement device of the present invention does not face the nozzle surface or the complicated structure directly on the upper part of the opening of the container as shown in the figure, the steam or liquid jumps from the filling contents. In addition, the content does not adhere to and accumulate on the nozzle surface or the complicated structure, and the content does not drop into the container.
[0021]
The can body that has been gas-replaced by passing through the inert gas replacement device passes through the low-oxygen atmosphere control tunnel 30, and is conveyed to the intake section of the seamer. Inert gas is blown into the low oxygen atmosphere control tunnel 30 from the nozzle plates 5 of the atmospheric gas nozzle bodies 2 and 2 at both sides at a uniform velocity distribution. Can be kept. Therefore, the can body whose head space has been gas-replaced in the previous step can be transported to the seamer while maintaining a low oxygen concentration, and a can with a high gas replacement rate can be obtained.
[0022]
Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various design changes can be made within the scope of the technical idea. For example, in the above embodiment, the replacement gas nozzle body 3 is provided only in a part of the can transport path from the filler to the seamer, and thereafter, only the atmosphere gas nozzle body is provided up to the seamer. May be provided continuously up to the intake portion of the seamer. Also, in the above embodiment, the case of the canned production line was described, but the present invention is not limited to cans, but can be used for containers such as bottles, cups, trays, bags, tubes, drinks, foods, seasonings, cosmetics, chemicals, and the like. This is effective when filling and sealing contents that deteriorate in quality due to oxidation.
[0023]
【The invention's effect】
As described above, according to the present invention, when performing gas replacement of the head space of a container filled with contents, without disposing a complicated structure on the upper portion of the container, it is difficult to perform gas replacement with a corner portion of a head space or The inert gas can be effectively replaced up to the shoulder, and a high gas replacement rate can be obtained even in a high-speed line. It is highly sterile and can be applied to aseptic filling. In addition, by arranging a porous diffuser tube inside the atmospheric gas nozzle body, the flow velocity distribution of the inert gas blown into the tunnel becomes uniform, so that the air is less trapped in the tunnel and the inside of the tunnel is kept low. The container is transported to the sealed position while maintaining the oxygen atmosphere, and the container can be sealed while maintaining the high gas replacement ratio.
[Brief description of the drawings]
FIG. 1 shows an inert gas replacement device according to an embodiment of the present invention, and is a cross-sectional view taken along line AA of FIG.
FIG. 2 is a layout view of a canned production line to which an inert gas replacement device according to an embodiment of the present invention is applied.
FIG. 3 is a sectional view taken along line BB of FIG. 2;
[Explanation of symbols]
REFERENCE SIGNS LIST 1 inert gas replacement device 2 atmosphere gas nozzle body 3 replacement gas nozzle body 5 nozzle plate 6 diffuser tube 7 socket 8 gas guide plate 10 semi-closed tunnel 11 chamber 12 slit nozzle 13 nozzle body 14, 15 nozzle body bottom face 16 gas guide plate Tip 19 Shielding plate 20 Can body 24 Lid 25 Seamer 30 Low oxygen atmosphere control tunnel 34 Inert gas nozzle body 35 Top plate

Claims (9)

In the inert gas replacement packaging line, at least the container and / or the lid being transported from both sides below the cover plate of the transport path of the container and / or the lid which is being transported toward the center of the transport direction above the container and / or the lid. By blowing, an inert gas flow toward the head space of the container and / or the lid being transported is formed, and the inert gas blown into the head space is convected to both sides from the center portion of the container in the transport direction, and the container head space is formed. A method for replacing an inert gas with a gas. The inert gas replacement method according to claim 1, wherein the transport path is a transport path from a content filling device to a sealing unit. 3. The inert gas replacement method according to claim 1, wherein the inert gas flow blown from both sides is collided near the center line of the transport path to form an inert gas flow toward the head space of the container. 4. The flow toward the head space of the container is formed by colliding an inert gas flow blown from both sides with a shielding plate provided along the transport path center line near the center line of the transport path. Inert gas replacement method according to the above. By forming a tunnel by covering the container transport path with a semi-hermetic type cover, and blowing out an inert gas from the side at a substantially uniform velocity distribution toward the vicinity of the container opening being transported in the tunnel, The gas replacement method according to any one of claims 1 to 4, wherein the inside of the tunnel is maintained in a low oxygen atmosphere. In the inert gas replacement packaging line, a cover plate is provided above the transfer path for transferring containers or lids with a predetermined gap from the container or lid being transported, and the cover plate is placed in the direction of the transport center line of the containers or lids. Displacement gas nozzles having slits for blowing active gas are arranged on both sides of the transport path, and are inactive in the direction of the transport center line of the container or lid from both sides of the transport path along the lower surface of the cover plate from the slits. An inert gas replacement device characterized by blowing a gas. The said conveyance path is a conveyance path from a content filling apparatus to a sealing part, The inert gas replacement apparatus of Claim 6 characterized by the above-mentioned. The inert gas replacement device according to any one of claims 6 to 7, wherein a shielding plate extending along a center line of the container transport path is provided at a central portion of a lower surface of the cover plate. An atmosphere gas nozzle body that blows out an inert gas from the side toward the transfer path along the can transfer path below the replacement gas nozzle body, and a porous diffuser tube is disposed inside the nozzle body. Item 10. An inert gas replacement device according to any one of Items 6 to 8.

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