JP2004123217A - Deoxidization method and device for can in can making line - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance a gas replacement efficiency without conducting undercover gassing and sufficiently reduce an amount of remaining oxygen in a can even by a high speed seamer. <P>SOLUTION: A tunnel-like cover is mounted in the area from a portion a little toward the seamer of a can transferring route reaching the seamer to the vicinity of an in-take portion of the seamer to form a tunnel 5. The oxygen scavenging means comprises a gas replacement zone 1 in the predetermined range of the inside of the tunnel, a low oxygen content can transferring zone 2 from the gas replacement zone 1 to the vicinity of the in-take portion of the seamer and a low oxygen content lid transferring zone 3 outward of a lid transferring portion by a can feed turret 13. The air of a head space is replaced with an inner gas in the gas replacement zone 1, and then the inner gas is blown from the low oxygen content can transferring zone 2, the low oxygen content transferring zone 3 and the side surface of the tunnel of the low oxygen content in-take zone to the center of the tunnel to keep the oxygen content in the tunnel zone of not more than 2%. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method and an apparatus for deoxidizing cans in a can production line for reducing the amount of oxygen remaining in the can by replacing air in the head space of the can with an inert gas during can production.
[0002]
[Prior art]
Conventionally, air in the head space is replaced with an inert gas such as nitrogen gas (hereinafter simply referred to as gas replacement) in order to prevent oxidation or deterioration of the contents during canning. It is widely practiced to reduce the amount of oxygen. The mainstream of the conventional gas replacement method is that an inert gas blowing nozzle is provided on a Cima feeder turret (gas turret) and an inert gas is supplied between the opening of the can and the inner surface of the lid when the lid is fitted to the can. (See Patent Document 1). Although this method has the advantage of performing gas replacement immediately before tightening in the seamer, it is performed in a very short time due to time restrictions due to the structure of the seamer itself. However, the amount of oxygen remaining in the can was not sufficiently reduced.
[0003]
Therefore, as a method of improving the gas replacement ratio, for example, in addition to the undercover gassing, the upper part of the conveying path of the filled cans fed from the filler to the seamer is covered with a U-shaped cross section or a hood with a perforated plate. Inert gas can be blown out from the upper part and blown directly into the head space of the can being conveyed, or the gas inside the can can be suctioned at the same time or immediately before the inert gas is blown to perform preliminary gassing. It has been proposed (for example, see Patent Documents 1 and 2). However, the conventional preliminary gassing method has a limit in reducing the amount of oxygen remaining in the can, and particularly in high-speed seamers, it has not been possible to sufficiently reduce the amount of oxygen remaining in the can. In order to solve this problem, the present inventors enclose a seam-side portion of the can conveying path from the filler to the seamer with a replacement frame, and provide a top wall vacuum suction port and a side wall near an inlet of the replacement frame. A vacuum suction port is provided, and air around the can body brought into the replacement frame by the can body is sucked out from the replacement frame side wall and the replacement frame top wall, and the replacement frame top wall and the replacement frame side wall are removed. Blowing an inert gas into the replacement frame by the amount corresponding to the amount of air carried into the replacement frame by high-speed transport of the filled can toward the inside of the replacement frame, the air in the head space of the filled can is turned into an inert gas. It has been previously proposed to perform substitution to reduce the amount of oxygen remaining in the can (see Patent Document 4).
[0004]
[Patent Document 1]
JP 2001-58609 A
[Patent Document 2]
JP-A-63-125118
[Patent Document 3]
JP-A-11-157507
[Patent Document 4]
JP-A-2002-46709
[0005]
[Problems to be solved by the invention]
The proposed method for reducing the amount of residual oxygen in the can can sufficiently reduce the amount of residual oxygen in the can even on a high-speed production line, and has provided an excellent effect. Then, by combining with undercover gassing, the residual oxygen is further reduced. However, undercover gassing has a disadvantage in that the gas replacement time is very short due to its structure, and the higher the line speed, the shorter the time for blowing the inert gas, thus lowering the replacement rate. are doing. To compensate for this, it is necessary to increase the flow rate of the inert gas to be blown. However, according to experiments performed by the present inventor, it has been found that when the flow rate of the inert gas exceeds a certain amount, air is entrapped on the contrary, and the residual oxygen amount in the canned head space may increase. Was. Further, there is also a problem that when the flow rate of the gas increases, the content liquid blows off and contaminates the inside of the seamer. Further, in the case of the combination with the liquid nitrogen filling method, the liquid nitrogen added to the head space of the can is blown off, so that the can pressure can be reduced so that the commercial value is lost, and the defective rate increases. The point is inherent. Therefore, there is a demand for a gas replacement method that can sufficiently reduce the residual oxygen in the can even without gas replacement by undercover gassing.
[0006]
Therefore, the present invention is intended to meet the above-mentioned demands by further improving the above-mentioned proposal. Provided is a method and an apparatus for deoxidizing cans in a canned production line, which can sufficiently reduce the amount of oxygen remaining in the can and can be easily applied without expanding a conventional production line. The purpose is to do.
[0007]
[Means for Solving the Problems]
According to the method for deoxidizing cans in a canned production line of the present invention which solves the above problems, a lid conveyed from a candy turret merges with a can conveyed by gas replacement and is fitted to the can. The section up to this is covered with a semi-hermetic cover to form a low oxygen concentration intake zone, and the lid is fitted to the can in an atmosphere in which the low oxygen concentration intake zone is maintained at an oxygen concentration of 2% or less. It is characterized in that it is wound with a seamer, whereby the conventional undercover gassing can be omitted.
[0008]
The transport path of the cans which are transported to the low oxygen concentration intake zone after being replaced by gas is covered with a semi-enclosed tunnel-like cover to form a tunnel, and a predetermined range of the inside of the tunnel near the filler side is replaced by gas. A zone, and a zone from the gas replacement zone to the low oxygen concentration intake zone is defined as a low oxygen concentration can transfer zone.In the gas replacement zone, an inert gas is supplied from above the can to a head space portion of the can being transferred. The air in the head space is blown to replace the inert gas with an inert gas, and then the inert gas is blown into the tunnel in the low-oxygen-concentration can transfer zone, and the oxygen concentration in the space through at least the can opening in the tunnel is reduced. The low oxygen concentration can is maintained at 2% or less, and the can filled with the contents and purged with an inert gas passes through the low oxygen concentration can transport zone to pass the low oxygen concentration intake. By to be over down transport, it is possible to convey the cans while maintaining the state of being gas replacement in the gas exchange zone effective to lower the oxygen concentration the intake zone.
[0009]
A semi-enclosed tunnel-like cover is provided around the outer periphery of the lid transport portion by the candy turret to form a low oxygen concentration lid transport zone, and the oxygen concentration in the low oxygen concentration lid transport zone is reduced to 2% or less. By maintaining and transporting the lid through the lid transport zone to the low oxygen concentration intake zone, it is possible to prevent air from being brought in by the lid and the candy turret, thereby more efficiently deoxidizing the can. Can be planned. Then, following the low oxygen concentration can transport zone and / or the low oxygen concentration lid transport zone, the transported lid transported from the tangential circular direction by the candy turret merges onto the can that is transported straight. A low oxygen concentration intake zone is formed by covering with a semi-hermetic cover until the low oxygen concentration intake zone is maintained at an oxygen concentration of 2% or less until the can is fitted to the can. Winding can be performed while maintaining the oxygen concentration, and undercover gassing can be omitted. By providing an inert gas curtain at the entrance of the gas replacement zone, it is possible to prevent the air introduced by the can from entering at the tunnel entrance. The flow rate of the inert gas blown into the head space of the can in the gas replacement zone is preferably in the range of 0.5 m / s to 10 m / s. If the flow rate of the inert gas is 0.5 m / s or less, the gas exchange rate of the head space is poor, and if it is 10 m / s or more, there is a problem that the contents are blown off.
[0010]
The deoxygenating apparatus for a can in the canning production line of the present invention for carrying out the above method is such that a lid conveyed from a tangential circular direction by a can feed turret merges with a can that is gas-displaced and straightly conveyed. Inert gas blowing means for forming a low oxygen concentration intake zone by covering a section until it fits into the can with a semi-hermetic cover, and blowing an inert gas laterally from the side into the low oxygen concentration intake zone. Is provided.
[0011]
Further, a semi-hermetic tunnel-shaped cover is provided to form a tunnel from a portion near the seamer of the can conveyance path which is conveyed after being replaced with gas to the low oxygen concentration intake zone, and a tunnel is formed near the filler side inside the tunnel. An inert gas blowing means for blowing an inert gas into a head space portion of the can being transported above the transport path in a predetermined range of the position is provided as a gas replacement zone, and from the gas replacement zone to the low oxygen concentration intake zone. By providing an inert gas blowing means that blows the inert gas toward the inside of the tunnel until it reaches, the can is transported to the low oxygen concentration intake zone while effectively maintaining the gas replaced state in the gas replacement zone It is possible to do. It is desirable that the inert gas blowing means in the low oxygen concentration can transport zone blows the inert gas into the side surface of the tunnel toward the center of the tunnel.
[0012]
Furthermore, a semi-hermetic tunnel-shaped cover is installed around the outside of the lid transporting portion by the candy turret to form a low oxygen concentration lid transport tunnel, and an inert gas is supplied from the side into the low oxygen concentration lid transport tunnel. By providing the inert gas blowing means for blowing in, air can be prevented from being brought in by the lid and the candy turret, and the can can be more efficiently deoxygenated. Further, following the low oxygen concentration can transport zone and / or the low oxygen concentration lid transport zone, the lid transported from the tangential circular direction by the candy turret onto the can that is transported straight ahead merges into the can. By covering the section until fitting with a semi-hermetic type cover to form a low oxygen concentration intake zone, and providing the inert gas blowing means for blowing inert gas laterally from the side in the low oxygen concentration intake zone. In addition, it is possible to perform winding while maintaining a low oxygen concentration in the can, and to eliminate undercover gassing. Furthermore, by providing an inert gas curtain portion at the entrance of the gas replacement zone, it is possible to reduce carry-in of can air into the gas replacement portion. In addition, the inert gas blowing means of the low oxygen concentration can transport zone and the low oxygen concentration intake zone is configured to blow the inert gas into a range of at least 20 mm width above the opening of the can and below the opening. It is desirable to arrange. Furthermore, by monitoring the oxygen concentration by arranging an oxygen concentration sensor for measuring the oxygen concentration in the tunnel in each or one of the gas transfer zone, the low oxygen concentration can transfer zone and the low oxygen concentration lid transfer zone can transfer, The amount of oxygen remaining in the can can be managed in real time.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail.
FIG. 1 is a schematic plan view showing an arrangement of a deoxidizer for cans in a canned production line according to an embodiment of the present invention, and FIGS. The deoxygenating apparatus of the present embodiment includes a can-conveying portion from a filler in a canned production line, a can-conveying portion between seamers, a lid-conveying portion by a candy turret, and an intake portion, which is a portion where the can and the lid merge and the can is covered with the lid. , And the portion is covered with a semi-closed tunnel-like cover to form a tunnel 5. The can transport portion is divided into a gas replacement zone 1 and a low oxygen concentration can transport zone 2 in order from the upstream side near the filler, the lid transport portion is a low oxygen concentration lid transport zone 3, and the low oxygen concentration The low oxygen concentration intake zone 4 is from the point where the can transport zone and the low oxygen concentration lid transport zone merge to the point where the lid is put on the can body and winding is started. In FIG. 1, reference numeral 10 denotes a can transport conveyor, 11 denotes a seamer (more specifically, a seamer half mode turret), 13 denotes a can feed turret, 14 denotes a discharge turret, and 15 denotes a discharge conveyor. Reference numeral 12 indicated by an imaginary line denotes a liquid nitrogen filling device which is provided when applied to a positive pressure canned production line for filling liquid nitrogen.
[0014]
As shown in cross sections in FIGS. 2 and 3, a portion constituting the gas replacement zone 1 of the tunnel 5 is provided along both sides of the can transport conveyor 10, and is supported by supporting posts 17 via brackets 18 as appropriate. Constitutes an inert gas blowing chamber 20 whose height can be adjusted according to the height of the can, and is arranged at a predetermined distance from the opening of the can being transported so as not to hinder the transport of the can. The bottom plate 21 is provided with a large number of outlets or multiple rows of fins at appropriate densities so that the inert gas supplied to the chamber is continuously blown downward. Reference numeral 22 denotes a socket for connecting an inert gas supply pipe for supplying an inert gas to the inert gas blowing chamber. A pair of left and right hanging walls 23 is provided below the inert gas blowing chamber 20 so as to cover both sides of the can being transported by about 30 mm downward from the opening of the can being transported. Extend over the gas displacement zone 1. The hanging wall 23 may extend to the bottom of the can height to form a completely closed tunnel shape completely surrounding the can transport path. However, as shown in FIG. If it is covered, substantially the same replacement efficiency can be achieved, so that it is not necessary to use a completely closed type, and a U-shape may be used so as to cover the upper part of the opening of the can and the upper part of the side wall of the can body. The semi-enclosed tunnel-shaped cover has an open section at the entrance of the can and the lid, and a gap is provided so as not to interfere with a driving section such as a conveyor or a candy turret of the can transport section. Although it is a closed type, it may be a closed type as long as it does not interfere with the drive unit. Therefore, the “semi-sealed tunnel-shaped cover” described in the claims is not necessarily limited to only the semi-sealed type as in the present embodiment, and a tunnel in which the hanging wall extends to near the bottom of the can. It should be construed to include a hermetically sealed version covered by a cover.
Further, in the present embodiment, the support posts 17 are provided upright on the can transport guides 16 provided along both sides of the can transport path. However, the support posts 17 are not necessarily based on the structure. The transport guide may be formed to have a narrow width, and the support post 17 may be provided directly on the fixed frame.
[0015]
The gas replacement zone 1 is configured as described above, and blows an inert gas into the head space portion of the can at a predetermined flow rate from the upper inert gas blowing chamber 20 toward the can brought into the gas replacement zone, Replace the air in the headspace of the can. Since the flow rate of the inert gas blown into the can head space affects the gas replacement rate of the can, the flow rate must be appropriate. The relationship between the flow rate of the inert gas and the replacement rate in the gas replacement zone 1 was examined by changing the flow rate of the inert gas. FIG. 6 shows the result. As shown in FIG. 6, when the flow rate is low, the replacement rate is poor, and as the flow rate increases, the replacement rate increases. At about 0.5 m / s, the replacement rate reaches 95%, and thereafter, the flow rate increases until about 2 m / sec. However, the replacement rate reaches about 99% at 2 m / sec. After that, even if the flow rate is increased, the replacement rate does not improve any more, and the replacement gas is wasted and 10 m / sec. If the temperature exceeds the limit, the phenomenon of liquid blow-off from the inside of the can occurs, causing inconvenience. Therefore, it was found that in the gas replacement zone, the flow rate of the inert gas blown out from the blowout chamber 16 is preferably in the range of about 0.5 to 10 m / s, more preferably in the range of 1 to 3 m / s.
Although not shown, it is desirable to provide an inert gas curtain for blowing down an inert gas in a film form at the entrance of the gas replacement zone 1 in order to prevent the air introduced by the can from entering.
[0016]
The low-oxygen-concentration-can transport zone 2 is provided continuously to the gas-replacement zone 1, and is configured as shown in cross sections in FIGS. In the low oxygen concentration can transfer zone 2, outside air enters the can head space while the can that has been gas-replaced in the gas replacement zone 1 is transported to the intake portion (the portion where the can and the lid are fitted) inside the seamer. In order to prevent an increase in the amount of oxygen, the inside of the tunnel is filled with a purge gas to shut off the outside air and maintain the inside of the tunnel at a low level of oxygen concentration. From the center of the transport path. In the present embodiment, the configuration of the low oxygen concentration can transport zone 2 of the tunnel 5 is substantially the same as that of the gas replacement zone. Zone 2 is different in that the zone 2 includes inert gas blowing chambers 24, 24. The ceiling is provided so as to be located slightly above the opening of the can, and may be constituted entirely by a blind plate. However, if necessary, the ceiling is not used as a purge gas or a replacement gas even from above the can. In the present embodiment, an inert gas blowing chamber 26 is provided so that the active gas can be blown out, similarly to the gas replacement zone.
[0017]
Inert gas blowing chambers 24, 24 as inert gas blowing means are provided in inert gas blowing frames 27, 27 provided along both sides of the can conveying path, and side plates facing the can conveying path. Is formed by a gas blowing plate having a slit or a porosity, and is configured so that a purge gas composed of an inert gas supplied into the chamber is blown laterally toward the center of the tunnel. In order to prevent air from entering or being caught in the head space of the can being transported, what is the range (nozzle width h) of the inert gas ejected toward the can being transported in the height direction? In order to check whether the above is most efficient, the relationship with the replacement ratio was examined by variously changing the width of the gas blowing plate of the purge gas blowing chambers 24, 24. As a result, a result as shown in FIG. 7 was obtained. According to this, the replacement ratio was higher as the nozzle width was larger above the opening of the can and below the opening, and the replacement ratio was maintained at about 95% for a 20 mm width and 98% for a 40 mm width. Therefore, in the present embodiment, the nozzle width h is maintained at least 20 mm width above the opening of the can and below the opening, preferably at least 40 mm width, so that the inert gas blowing chamber 24, 24 side plates 25 were configured. It is effective to blow the inert gas laterally from the side of the tunnel toward the center of the tunnel, but it is also possible to blow the inert gas from the left and right chambers simultaneously or from only one chamber.
[0018]
As shown in FIG. 5, the low oxygen concentration lid transport zone 3 is configured by covering the outer periphery of the candy turret from the lid stack portion to the intake portion of the candy turret 13 with a semi-enclosed cover 30, and comprises a candy turret. An inert gas blowing chamber 34 serving as inert gas blowing means for blowing an inert gas into a bottom space of the lid being transported under the lid transport guide 33 which transports and guides the lid in cooperation with the outer peripheral edge of the pocket 31 of the thirteen. Is arranged. The inert gas from the inert gas blowing chamber is blown laterally from the side to the center. As a result, a portion where the oxygen concentration inside the semi-enclosed cover is maintained at a low level is formed, and when the lid passes through the portion, the oxygen concentration around the lid and the pocket 31 can be reduced. By fitting into the can and winding in that state, it is possible to prevent air from being brought into the can by the lid and the candy turret. As a result, as shown in the graph of FIG. 7 described later, the gas replacement ratio can be further increased.
[0019]
In addition, the blowing of the inert gas to the lid conveyance section is not limited to the conveyance guide side, but also a blowing nozzle is provided on the candy turret 13 as schematically indicated by an arrow 35 to move from the turret side to the peripheral portion. You may make it blow in the horizontal direction. Or you may make it blow in from both a guide side and a turret side. The oxygen concentration in the low oxygen concentration lid transfer zone 3 is maintained at 2% or less, desirably 0.1% or less, similarly to the low oxygen concentration can transfer zone 2 for the reason described later.
[0020]
The low oxygen concentration intake zone 4 is conveyed from the tangential circular direction by the can feed turret 13 onto the can 7 which is conveyed straight ahead, following the low oxygen concentration can conveyance zone 2 and the low oxygen concentration lid conveyance zone 3. The semi-enclosed cover covers the space from when the coming lid 8 joins and fits into the can, and blows out an inert gas to one side of the side of the can conveying path that continues from the low oxygen concentration can conveying zone 2. A frame 27 is provided in the inside of which a chamber that blows out an inert gas from the lateral direction toward the center of the tunnel is disposed in the same manner as in the low oxygen concentration can transport zone 2 to reduce the oxygen concentration in the tunnel to 2%. In the following, the low level is desirably maintained at 0.1% or less. As described above, in the low oxygen concentration intake zone 4, the inert gas is not directly blown into the inside of the can with a nozzle as in the conventional undercover gassing, but the inert gas is injected around the can and the lid. By doing so, the surrounding area is maintained at a low oxygen concentration and the gas replacement rate in the can is maintained at a high rate, so that the content liquid is not blown off and the seamer is not contaminated, and undercover gassing is performed. And the high substitution rate can be achieved. In the case of the liquid nitrogen filling line, since the liquid nitrogen is not blown off by undercover gassing, a stable internal pressure of the can is obtained.
[0021]
In order to examine the relationship between the oxygen concentration and the gas replacement rate in the low oxygen concentration can transfer zone, the low oxygen concentration lid transfer zone, and the low oxygen concentration intake zone, the replacement rate was measured while changing the oxygen concentration. FIG. 8 shows the result. In FIG. 8, when the tunnel is not provided in the lid transport section but is provided in the can transport zone and the intake zone to form only the low oxygen concentration can transport zone and the low oxygen concentration intake zone (diagram a), the can transport zone In the case where a low oxygen concentration can transport zone, a low oxygen concentration lid transport zone and a low oxygen concentration intake zone were formed in the lid transport zone and the intake zone (diagram b), the measurement was performed separately. As a result, in both cases, if the oxygen concentration in the tunnel is within 2%, only the gas replacement is performed at the tunnel entrance without undercover gassing, and the final replacement rate is 95% or more. It turns out that it can be achieved. However, when the oxygen concentration is 2% or more, the substitution rate decreases, and a desired high substitution rate cannot be achieved. Therefore, the oxygen concentration in the tunnel is set to 2% or less, preferably 1% or less.
[0022]
As can be seen from the graph of FIG. 8, when the low oxygen concentration can transport zone, the low oxygen concentration lid transport zone and the low oxygen concentration intake zone are formed, only the low oxygen concentration can transport zone and the low oxygen concentration intake zone are formed. As compared to the case, a higher gas replacement rate can be achieved. Therefore, it is desirable that the lid transport zone is also provided with a tunnel to have a low oxygen concentration zone, but if the contents are not very susceptible to oxygen, only a low oxygen concentration can transport zone and a low oxygen concentration intake zone are provided. Can achieve the purpose.
[0023]
As described above, the embodiments of the present invention have been described in detail. However, the present invention is not limited to the above embodiments, and various design changes can be made within the technical scope. For example, the configuration of the tunnel of the gas replacement zone, the low oxygen concentration can transport zone, the low oxygen concentration lid transport zone, and the low oxygen concentration intake zone, and the configuration of the inert gas blowing means are not limited to the above-described structures, and may be appropriately changed. Design changes are possible. In addition, although the present invention generally uses nitrogen gas as the inert gas, by using carbon dioxide gas instead of nitrogen gas, the present invention can also be applied to the case where the contents are beer or carbonated beverage. Furthermore, although not shown in the above embodiment, an oxygen concentration sensor for measuring the oxygen concentration in the tunnel is arranged at each or one of the gas replacement zone, the low oxygen concentration can transport zone and the low oxygen concentration lid transport zone. By monitoring the oxygen concentration, the amount of oxygen remaining in the can can be managed in real time. As a result, if an abnormal operation of the system occurs, it can be detected at an early stage, so that an accident that generates a large amount of defective cans can be prevented.
[0024]
【Example】
In order to confirm the effects of the method and apparatus for deoxidizing cans in a canned production line according to the present invention, a headspace volume was set to 21 ml for a 200 ml-sized can in a canned production line equipped with the apparatus shown in the embodiment. After filling with water at normal temperature, gas replacement was carried out by the method of the present invention, and the gas replacement ratio of the cans which were hermetically sealed and wound was measured. Further, as Comparative Example 1, when a can under the same conditions as in the example was filled with water at room temperature under the same conditions, and gas replacement was performed only by the conventional undercover gassing, and as Comparative Example 2, Cima Inert gas was blown into the opening of the can on the can conveyor to perform gas replacement, and the gas replacement ratio was measured when undercover gassing was performed. The result is shown in FIG. FIG. 9 shows the average value of the results obtained for 15 cans.
[0025]
As a result, in Example (Graph C) of the present invention, the residual oxygen amount in the head space in the can was 0.1 ml / can, and the gas replacement ratio was 98%. On the other hand, in Comparative Example 1 (Graph A), the residual oxygen amount was 0.7 ml / can and the gas replacement rate was 85%. In Comparative Example 2 (Graph B), the residual oxygen amount was 0.3 ml / can and the gas replacement rate was 93%. there were. As is clear from the results, the gas exchange rate in the example is particularly improved as compared with the comparative example, and the method and apparatus for deoxidizing cans in the canned production line of the present invention are different from the comparative example. It was confirmed that the rate was effective.
[0026]
【The invention's effect】
As described above, according to the first to eleventh aspects of the present invention, a method is used in which the tunnel passing through the gas replacement unit to the intake unit is surrounded by a tunnel to reduce the oxygen concentration inside the tunnel. In addition, the residual oxygen in the head space of the can can be efficiently replaced with an inert gas, and is less affected by the line speed. Therefore, gas replacement can be performed with high efficiency even in a high-speed line. In addition, since the conventional undercover gassing is not used, the inside of the seamer is not contaminated by blowing out the content liquid. Since undercover gassing is not used, liquid nitrogen is not blown off even in a high-speed line in combination with the liquid nitrogen filling method, a stable internal pressure of the can is obtained, and the defective rate can be reduced. Further, the can deoxidizing apparatus of the present invention has an effect of having a function of a cover for preventing foreign matter from being mixed in a portion where cans are transported from a filler to a seamer in a canning production line.
[0027]
According to the second and seventh aspects of the present invention, the can can be transported to the low oxygen concentration intake zone while maintaining the gas-replaced state, and the lid can be tightened with the high-replacement rate maintained. it can. Furthermore, according to the third and eighth aspects of the present invention, air can be prevented from being brought in by the lid, and the can can be more efficiently deoxygenated. Further, according to the inventions of claims 4 and 9, it is possible to prevent the air brought in by the can at the entrance of the tunnel from entering, and it is possible to further improve the gas replacement efficiency. Further, according to the invention of claim 11, the oxygen concentration in the gas transfer zone, the low oxygen concentration can transfer zone and the low oxygen concentration lid transfer zone can transfer can be monitored, and the amount of oxygen remaining in the can is managed in real time. be able to.
[Brief description of the drawings]
FIG. 1 is a plan layout view showing a main part of a canned production line to which a can deoxidizer according to an embodiment of the present invention is applied.
FIG. 2 is a view taken in the direction of arrows AA in FIG. 1;
FIG. 3 is a view taken in the direction of arrows BB in FIG. 1;
FIG. 4 is a view taken in the direction of arrows CC in FIG. 1;
FIG. 5 is a view as seen in the direction of arrows DD in FIG. 1;
FIG. 6 is a diagram showing a relationship between a flow rate of an inert gas and a gas replacement rate in a gas replacement section.
FIG. 7 is a diagram illustrating a relationship between an inert gas blowing nozzle width and a replacement rate in a low oxygen concentration can transport zone.
FIG. 8 is a graph showing a relationship between an oxygen concentration and a gas replacement ratio in a low oxygen concentration can transport zone.
FIG. 9 is a graph showing a comparison of gas replacement rates in Examples and Comparative Examples.
[Explanation of symbols]
1 Gas replacement zone 2 Low oxygen concentration can transport zone
3 Low oxygen concentration lid transfer zone 4 Low oxygen concentration intake zone
5 tunnels 7 cans
8 Lid 10 Can conveyor
11 Cima 13 Can feed turret
16 Can transport guide 17 Support post
18 Bracket
20, 24, 26, 34 Inert gas blowing chamber
21 Bottom wall 23 Hanging wall
30 Semi-hermetic cover 31 Pocket
33 Lid transport guide

Claims (11)

A method for deoxidizing cans in a canned production line in which a gas in a can head space after filling with contents is replaced with an inert gas and tightly sealed by sealing, wherein a can feed is performed on a can which is gas-replaced and conveyed. The section until the lid conveyed from the turret merges and fits into the can is covered with a semi-hermetic cover to form a low oxygen concentration intake zone, and the low oxygen concentration intake zone is reduced to an oxygen concentration of 2% or less. A deoxygenating method for a can in a canning production line, wherein a lid is fitted to the can in a maintained atmosphere, and the can is wound with a seamer in that state. The transport path of the cans which are transported to the low oxygen concentration intake zone after being replaced by gas is covered with a semi-enclosed tunnel-like cover to form a tunnel, and a predetermined range of the inside of the tunnel near the filler side is replaced by gas. A zone, and a zone from the gas replacement zone to the low oxygen concentration intake zone is defined as a low oxygen concentration can transfer zone.In the gas replacement zone, an inert gas is supplied from above the can to a head space portion of the can being transferred. The air in the head space is blown to replace the inert gas with an inert gas, and then the inert gas is blown into the tunnel in the low-oxygen-concentration can transfer zone, and the oxygen concentration in the space through at least the can opening in the tunnel is reduced. The low oxygen concentration can is maintained at 2% or less. Deoxidation method can in canning line according to claim 1 comprising as the over down conveyor. A semi-enclosed tunnel-like cover is provided around the outer periphery of the lid transport portion by the candy turret to form a low oxygen concentration lid transport zone, and the oxygen concentration in the low oxygen concentration lid transport zone is reduced to 2% or less. 3. The method for deoxidizing cans in a canned production line according to claim 1, wherein the lid is transported to the low oxygen concentration intake zone through the lid transporting zone while maintaining. 3. The method for deoxidizing cans according to claim 2, wherein an inert gas curtain portion is provided at an entrance of the gas replacement zone to prevent entry of air brought into the can at a tunnel entrance. The method for deoxidizing a can according to any one of claims 1 to 4, wherein an inert gas is blown into the head space portion of the can at a flow rate of 0.5 m / s to 10 m / s in the gas replacement zone. A can deoxygenation device in a can manufacturing line that replaces the gas in the head space of the can after filling with inert gas with an inert gas and tightly seals the can. The section until the lid conveyed from the tangential circular direction by the candy turret merges and fits into the can is covered with a semi-hermetic cover to form a low oxygen concentration intake zone. An apparatus for deoxidizing cans in a canned production line, comprising an inert gas blowing means for blowing out inert gas laterally from the side. From the portion near the seamer of the can transfer path that is transferred by gas replacement to the low oxygen concentration intake zone, a tunnel is formed by providing a semi-enclosed tunnel-shaped cover, and a position near the filler side inside the tunnel is provided. A gas replacement zone is provided by providing an inert gas blowing means for blowing an inert gas into a head space portion of the can being transported above the transport path in a predetermined range to form a gas replacement zone, and from the gas replacement zone to the low oxygen concentration intake zone. 2. The can deoxidizing apparatus according to claim 1, wherein an inert gas blowing means for blowing an inert gas toward the inside of the tunnel is provided to form a low oxygen concentration can transport zone. A semi-hermetic tunnel-shaped cover is provided around the outside of the lid transporting portion by the candy turret to form a low oxygen concentration lid transport tunnel, and an inert gas is blown from the side into the inside of the low oxygen concentration lid transport tunnel. The can deoxidizer according to claim 6 or 7, further comprising an active gas blowing means. The deoxygenating device for a can according to any one of claims 6 to 8, wherein an inert gas curtain portion is provided at an inlet of the gas replacement zone. The inert gas blowing means of the low oxygen concentration can transport zone and the low oxygen concentration intake zone are arranged so as to blow the inert gas into a range of at least 20 mm width above the opening of the can and below the opening. The can deoxidizer according to any one of claims 6 to 9, wherein An oxygen concentration sensor for measuring the oxygen concentration in the tunnel is arranged at each or one of the gas replacement zone, the low oxygen concentration can transfer zone and the low oxygen concentration cover transfer zone, and the oxygen concentration is monitored. The can deoxidizer according to any one of claims 6 to 10.

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