JP5442241B2 - Container gas replacement method and apparatus - Google Patents

Description

  The present invention relates to a gas replacement method and apparatus for injecting an inert gas into a head space of a content-filled container such as a beverage can to replace residual gas in the head space.

  Conventionally, a gas that replaces a residual gas in a head space of a container filled with contents (hereinafter, a case of a can as a typical container) with a replacement gas (typically an inert gas such as nitrogen gas). As a replacement method, as shown in FIG. 7, the replacement is performed from the horizontal direction between the lid and the can opening immediately before the lid 33 covers the can 30 between the gas turret 1 and the seaming turret 2 immediately before the lid is tightened. There is known a method (so-called undercover gassing method) in which a gas is blown in for replacement. Since the replacement gas in the undercover gassing is injected in a horizontal direction from the inner peripheral surface of the arc-shaped recess (pocket) 3 of the gas turret 1 toward the gap between the can opening and the lid, most of the replacement gas is There is a problem that the replacement efficiency is poor because it passes between the can and the lid without entering the inside of the can. Conventionally, the gas replacement is performed by directing the replacement gas blown in the horizontal direction as much as possible in the can and the bottom of the lid. Various ideas have been proposed, such as increasing efficiency.

  For example, a large replacement gas flow path to the replacement nozzle is formed (provided with a so-called buffer), and a group of blowout holes of the nozzle is blown toward the flange of the can lid. The second gas jet holes that blow out into the space under the lid in the perpendicular direction and the third gas jet holes that blow out to the wall part below the can mouth edge are provided in three stages in the vertical direction (patents) Reference 1), by providing a branch body that branches the gas flow left and right at the center of the replacement gas injection flow path and forming nozzles on the left and right, the replacement gas injected from the pair of nozzles is centered in the upper space in the can By causing collision, the replacement gas is directed toward the liquid level of the head space of the can (see Patent Document 2), a guide plate is provided in the replacement gas injection flow path, and the replacement gas flow blown out from the injection port is Swirling flow in the upper space of the can Proposed (see Patent Document 3), and those in which the replacement gas blown out from the pair of left and right outlets collides in a substantially linear collision area (see Patent Documents 4 and 5). ing.

Japanese Patent Publication No.49-28627 JP-A-8-324513 JP 2000-219213 A JP 2004-59016 A JP 2005-59885 A

  In the gas replacement method for containers, the most ideal gas replacement method is to reduce the amount of residual oxygen in the container, the amount of consumption of the replacement gas, and the amount of liquid spillage from the container at the time of replacement. All of these methods are aimed at achieving this ideal technical challenge, but these challenges are technically conflicting and if one requirement is met, the other requirement must be sacrificed, It is difficult to achieve three quantities at the same time, and a satisfactory one has not yet been obtained. For example, according to the method of Patent Document 1 described above, if the replacement gas flow rate is increased, a reduction in the amount of residual oxygen (that is, an improvement in the replacement rate) can be obtained, but there is a problem that a large amount of replacement gas is consumed. is there. On the other hand, in the methods shown in Patent Documents 2 to 5, the replacement gas flow is made to collide with the liquid surface by forming a swirl flow in the container or colliding the jet flow along the center or the center line, and in the vicinity of the liquid surface. However, since it is necessary to increase the speed of the replacement gas jet in order to increase the replacement efficiency, the liquid is affected by the impact of the replacement gas flow that collides with the liquid surface. There is a problem that spillage is likely to occur. Undercover gassing is performed in an unstable place that changes from a straight track to a circular track, and in recent years, high-speed production of 1000 to 2000 cans per minute has been carried out, so there is a problem that liquid spillage is likely to occur even with a slight impact. However, the proposed method has not yet reduced the amount of liquid spilling satisfactorily.

  Accordingly, the present invention provides a gas replacement method capable of simultaneously reducing the above-mentioned problems that could not be achieved, that is, the remaining oxygen amount, the consumption amount of the replacement gas, and the amount of liquid spillage from the can at the time of replacement, and its The object is to provide an apparatus.

In order to achieve the above-mentioned problems, the present inventor has conducted intensive research on the causes of the above-mentioned problems that cannot be satisfactorily achieved in the conventional gas replacement method.
(1) The collision of the gas flow ejected from the nozzle toward the opening of the container at the center deflects the replacement gas flow in the vertical direction so that the replacement gas flow strikes the liquid surface and the residual air existing in the vicinity of the liquid surface. Although it is effective for expelling and replacing with the replacement gas, blowing the replacement gas into the head space at a high flow rate increases the impact of the replacement gas hitting the liquid surface, resulting in liquid spillage. In order to reduce this, it is conceivable to reduce the flow rate of the replacement gas, but in order to inject a predetermined amount of replacement gas from the limited opening area (range) of the nozzle at a predetermined time, a predetermined flow rate is required. It is necessary to ensure.
(2) Under cover gassing, as shown in FIG. 5 in the prior art, vortex 6 is generated in the vicinity of both ends of the can head space in the can traveling direction (in front of both end portions of the nozzles) S, which becomes a stagnation and improves the replacement efficiency. It is decreasing.
(3) When the replacement gas is blown into the head space, the replacement gas is entrained by the air existing on the outer peripheral surface of the can neck portion, which is detrimental to improving the head space replacement rate.

  As a result of further research to solve the above causes, in order not to cause liquid spillage, a main gas jet flow that goes straight outward from the nozzle through the center of the container is formed and symmetrically from both sides. It has been found that by making the sub-gas injection flow having a predetermined angle collide, the flow velocity of the replacement gas flow descending to the liquid surface side is weakened and the impact colliding with the liquid surface can be mitigated. In addition, it has been found that the cause of (2) can be solved by making the circumferential nozzle opening range wider than before to eliminate the occurrence of vortices to the location. Furthermore, it has been found that the cause of (3) can be reduced by setting the length in the opening height direction of the nozzle within a predetermined range. Further, by adopting the means (2) and (3), the jet gas flow becomes slower than the conventional one, and the entrainment of air at the time of inflow is reduced and the amount of residual oxygen is reduced within a predetermined time. It was found that the amount of liquid spillage can be further reduced in combination with the means (1).

The present invention has been achieved on the basis of the above knowledge, and includes the following components.
That is, the gas replacement method for a container according to the present invention that achieves the above object is a gas replacement method in which a replacement gas is blown into the head space of a content-filled container to replace the residual gas in the head space. A main gas jet flow that blows outward from the edge of the container opening through the center of the opening, and a secondary gas that blows symmetrically across the main gas injection flow at a predetermined angle with respect to the center of the container opening. A gas injection flow is formed, gas replacement is performed by colliding the main gas injection flow and the sub gas injection flow, and the sub gas injection flow blown symmetrically at a predetermined angle with respect to the main gas injection flow The injection angle is between 100 ° and 130 ° .

In addition, the gas replacement device for a container according to the present invention that achieves the above replacement method is the gas replacement device that blows the replacement gas into the head space of the content-filled container and replaces the remaining gas with the center of the opening from the container opening edge. A main gas injection passage for blowing the replacement gas through the outside and a replacement gas symmetrically with respect to the main gas injection flow having a predetermined angle with respect to the center of the container opening and sandwiching the main gas injection passage An opening of the main gas injection channel and the auxiliary gas injection channel has a predetermined length in the height direction so as to inject gas into the upper part of the container opening and the upper part of the container , In addition, the angle formed by the direction in which the opposing replacement gas blows out from the sub-gas injection channel is 100 ° to 130 ° .

In the gas replacement method and apparatus for the container, it is preferable that the injection angle between the sub gas injection flows that are blown symmetrically at a predetermined angle with respect to the main gas injection flow is 100 ° to 130 °. By increasing the ejection angle in this way, it is possible to prevent gas stagnation in the head space. If the spray angle is smaller than 100 °, it becomes the same as the conventional replacement nozzle body, and the effect of suppressing the head space vortex generation is small. A larger angle is desirable for the upper limit, but it is difficult to set it to 130 ° or more because of structural limitations of the gas turret. The gas replacement method and apparatus can be suitably applied to an undercover gassing method and apparatus for a can winder, in which case the replacement gas flow blown from the replacement nozzle is adjusted to the height of the can lid and the length of the can neck. It is desirable to blow out from a nozzle having an opening in the height direction longer than the sum of 1/3.
And, in the under cover gassing device of the can winder, the gas replacement device has a pair of fingers provided on both sides of the gas turret pocket of the under cover gassing device, and the upper surface of the sub gas injection flow path of the nozzle body By devising it so as to be provided at the position, it is possible to widen the injection opening of the nozzle body facing the pocket and to make the angle of the auxiliary gas injection flow path 110 ° or more.

According to the first and third aspects of the present invention, the main gas jet collides with the chuck wall of the can lid by colliding the main gas jet with the sub gas jet having a predetermined angle symmetrically from both sides. As a result, the flow velocity of the replacement gas flow that descends to the liquid surface side by colliding with the descending replacement gas flow or the sub-gas injection flow can be reduced, the impact that collides with the liquid surface can be mitigated, and gas replacement is effectively performed. In addition, liquid spillage from the head space can be reduced. Therefore, according to the present invention, it is possible to reduce both the residual oxygen amount and the liquid spillage amount with the same use amount of the replacement gas as compared with the conventional comb-shaped nozzle.
Further, it is possible to prevent gas stagnation in the head space by increasing the injection angle between the sub gas injection flows which are blown symmetrically at a predetermined angle with respect to the main gas injection flow to 100 ° to 130 °. , The replacement rate can be increased. Further, since the replacement nozzle range is expanded, it is possible to reduce the flow velocity in order to blow a predetermined amount of replacement gas into the head space, which is effective in suppressing liquid spillage.

Further, according to the inventions of claims 2 and 4 , the outer peripheral surface of the can neck portion can be made into a replacement gas atmosphere, and when the replacement gas is blown into the head space, air is entrained from the outer peripheral surface of the can neck portion. This is effective in improving the head space replacement rate.
Further, with the configuration of the fifth aspect , it is structurally possible to make the opening angle in the circumferential direction of the replacement nozzle (injection angle with respect to the central portion) larger than in the past.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a plan sectional view of an essential part of an undercover gassing device according to an embodiment of the gas replacement device of the present invention, and is provided so as to face an arcuate recess (pocket) 3 of a gas turret 1 shown in FIG. It is done. As shown in FIG. 2, the nozzle body 11 is fixed to the upper surface of the gas turret body 10 of the gas turret 1, and the replacement gas flow path 12 communicating with each arcuate recess 3 is formed inside the nozzle body.
In the present embodiment, the replacement gas flow path 12 leading to the replacement gas supply port 14 is formed in a straight having a substantially equal height, as shown in FIG. It is not done. The replacement gas flow path 12 is partitioned at the tip by a plurality of wind direction adjusting plates 13 and faces the arcuate recess 3 to form a plurality of replacement gas injection flow paths. The injection flow path of the present embodiment is a main gas injection flow path 15 through which the replacement gas is jetted so that the replacement gas advances straight and passes through the center of the can opening to the opposite side. The auxiliary gas injection flow path 16 is formed symmetrically with a predetermined angle with respect to the center of the container opening with the flow path 15 interposed therebetween. The auxiliary gas injection channel 16 is formed at least near the outermost part of the arc recess, and in this embodiment, a plurality of sub gas injection channels 16 and the main gas injection channel 15 on the center are further provided. Although the intermediate sub-gas injection channel 17 is formed, the intermediate sub-gas injection channel 17 is not necessarily formed.

Then, in the present embodiment, the sub-gas injection passage 16 may be a replacement gas blowout angle theta ₁ are to 120 ° greater relative arcuate recess center, the largest different in comparison with the conventional apparatus It is in place. That is, the blowing angle of the nozzle in which the ejection flow paths are conventionally arranged radially is within 100 ° at the maximum. As shown in FIG. 5, the present inventor has found that in the conventional under cover gassing method, a vortex 6 is generated in the container opening at the nozzle outlet base outer side position S, and gas stagnation occurs in that portion, resulting in gas replacement. As a means to solve the problem that the spillage is not performed well and the liquid spillage that occurs at the time of gas replacement, it has been found that these problems can be solved by increasing the opening area (blowing angle) of the blowing port. It was. However, in the conventional gas turret 1, as shown in FIGS. 5 and 6, the can lids 33 placed on the outer peripheral edge of the pocket are positioned in the pockets at both ends of the arc-shaped recess 3 of the gas turret body 10 and conveyed. Since the finger 4 is provided on the nozzle 4 and the nozzle body 5 is provided between them, the installation range of the ejection nozzle arranged on the peripheral surface of the pocket is naturally limited, and it can be installed only within a maximum of 100 °, usually 80 °. It is formed only to the extent.

  Therefore, in the present invention, in order to widen the installation range of the replacement nozzle, the conventional finger 4 is removed from the turret body 10 and the range of the replacement nozzle is expanded to the position where the conventional fingers 4 and 4 are located. A nozzle body was formed, and fingers 4 and 4 were provided on the nozzle body 11 as shown in FIGS. As a result, the range of the replacement nozzle could be expanded to 120 °, and the sub-gas injection flow channel 16 could be formed so that the facing angle became 120 ° toward the center. As a result, it was possible to increase the area of the injection flow path and to reduce the entrainment of air by slowing the flow velocity when injecting the replacement gas with the same flow rate, and to suppress the occurrence of vortex in the head space.

  Further, in the present invention, when the replacement gas is blown from the replacement nozzle, the vicinity of the outer surface of the neck portion 31 is replaced with a replacement gas in order to reduce the amount of air that is located on the outer periphery of the neck portion of the can body as shown in FIG. In order to form an atmosphere, the replacement gas has a higher nozzle outlet height than a conventional comb-type nozzle. The height h of the gas injection flow path, that is, the length h in the height direction of the gas flow path is a + b / 3 ≦ h ≦ a + b, where the lid height is a and the can shoulder portion dimension is b as shown in FIG. A range satisfying the relationship of /1.5 is desirable. If the length h in the height direction of the gas flow path is lower than the above range, the injection flow rate becomes faster, liquid spillage is likely to occur, and the amount of outside air entrainment increases, making it difficult to improve the replacement rate. On the contrary, if it is higher (larger) than the above range, the replacement gas consumption will increase, so the above range is desirable.

As described above, the gas replacement device of the present embodiment is configured as described above, and the angle formed by the direction of replacement gas ejection from the auxiliary gas injection flow path 16 is 120 °, which is particularly wide compared to the conventional case. Thus, the generation of vortices in the vicinity S of the nozzle outer end is eliminated, and there is no stagnation of the flow in the vicinity of the nozzle, so that the replacement can be performed efficiently with a small amount of replacement gas. Further, since the opening area of the nozzle could be increased by increasing the opening angle of the nozzle, the average flow velocity of the replacement gas flow was reduced, and the amount of liquid spillage was reduced. In addition, since the average flow velocity of the replacement gas flow is reduced, the replacement gas also reduces external air entrainment, which is effective in reducing the amount of residual oxygen.
As the replacement gas, an inert gas such as nitrogen or carbon gas is usually used.

More specifically, the gas replacement in the present embodiment can be more effectively performed by the following mechanism.
As shown in FIG. 4, the main injection gas flow injected from the main gas injection flow passage 15 pushes the gas in the head space out of the can and exits out of the can while proceeding substantially straight in the center in the height direction. At the same time, the auxiliary gas injection flow 21 injected from the left and right auxiliary gas injection flow paths 16 collides at a substantially central portion of the can and becomes a downward flow, spreads to the liquid surface and strikes the liquid surface, but does not radiate without the conventional straight flow in the center. Compared with the case of only the flow, the collision impact of the secondary gas injection flow is mitigated by the main gas injection flow by colliding with the main gas injection flow 20, and the main gas injection flow collides with the chuck wall of the can lid. The descending replacement gas flow is relaxed by the side gas flow that is blown symmetrically from both sides, so that the impact of hitting the liquid surface is weak and liquid splashes and spills can be reduced.
Further, in the present invention, the height direction length h of the injection flow path is formed to be higher than 1/3 of the can lid height a and the can neck portion length b, as shown in FIG. The gas flow injected from the upper part of the nozzle opening of both the main gas injection flow 20 and the sub gas injection flow 21 enters the head space after hitting the chuck wall 34 of the can lid 33 and hits the liquid surface. Since the nozzle opening area is large as described above, the flow velocity is slow by that amount, so that the impact of hitting the liquid surface is small, and gas replacement in the vicinity of the liquid surface and the inner peripheral surface of the can is efficiently performed without causing liquid spillage. It can be carried out. On the other hand, the gas flow from the lower part of the nozzle opening hits the outer peripheral surface of the neck part 31 of the can, and by making the vicinity a replacement gas atmosphere, it is possible to prevent the outside air from being sucked into the can.

  In order to confirm the effect of the present invention, when performing under cover gassing with the can winding device shown in the above embodiment under the following setting conditions, and when performing with a conventional comb-shaped nozzle as a comparative example, In addition, the nozzle body in which the buffer is provided by the comb-tooth nozzle was evaluated by analyzing the changes in the remaining air amount and liquid spillage amount with respect to the replacement gas injection time by numerical analysis.

Example:
(1) Gas displacement device Angle of a pair of sub gas injection flow paths 16: 120 ° Height of gas flow path: h = 12 mm
(2) Gas replacement conditions Can shape: trunk diameter 66mm, opening diameter 60mm, can shoulder height 18mm
Can lid shape: 7mm lid height
Type and amount of inner solution: 350 g of deaerated water,
Headspace volume: 19.2 ml
Replacement gas type: Carbon dioxide
(3) Measurement method Residual air amount: Calculated from the carbon dioxide concentration per unit time of the head space as the initial air of the head space. Liquid spillage amount: Accumulate the flow rate of the passing liquid by creating a surface in the can flange did.

  The results are shown in FIGS. FIG. 8 shows changes in the remaining air amount and liquid spillage in the head space when the replacement gas flow rate is changed to 450 Nl / min, 600 Nl / min, and 900 Nl / min. FIG. 9 shows the amount of liquid spillage and the amount of remaining air (ml) in the headspace when the replacement gas flow rate is 900 Nl / min.

Comparative example:
As a comparative example, the same conditions and the same method as in the example are used for the case where the conventional comb-tooth nozzle is used (Comparative Example 1) and the case where the comb-shaped nozzle is used for the nozzle body provided with a buffer (Comparative Example 2) Thus, the changes in the amount of remaining air and the amount of liquid spillage with respect to the replacement gas injection time were evaluated by numerical analysis. The results are shown in the graphs of FIGS. 8 and 9 together with the examples. FIG. 8 shows changes in the remaining air amount and liquid spillage in the head space when the nozzle body of Comparative Example 2 is changed to 600 Nl / min, 900 Nl / min, and 1200 Nl / min. FIG. 9 shows the amount of liquid spillage and the amount of air remaining in the head space (ml) when Comparative Example 1 is performed at a replacement gas flow rate of 900 Nl / min, and when Comparative Example 2 is at a replacement gas flow rate of 900 Nl / min and 1200 Nl / min. Indicates.

In the graph of FIG. 8, ▲ indicates an example, ● indicates a comparative example 2, △ indicates an example, ◯ indicates a comparative example 2 (900 Nl / min), and ● indicates a comparative example 2 (1200 Nl / min). ) And ■ show the case of Comparative Example 1, respectively.
As is apparent from the graph of FIG. 8, in the case of the example, the remaining air and the liquid spillage amount are significantly reduced at the flow rate of 600 Nl / min compared to the injection flow rate of 900 Nl / min in the comparative example 2. Similarly, in the case of 900 Nl / min injection in the example, both the remaining air amount and the liquid spillage amount are reduced compared to the case of 1200 Nl / min injection in the comparative example, and the residual air amount equivalent to the example in Comparative example 2 It can be seen that in order to reduce the amount, the amount of substitution gas increased by about 30% from the embodiment must be used.

  On the other hand, in the graph of FIG. 9, when gas replacement is performed with the same amount of replacement gas as the replacement gas injection amount 900 Nl / min in both the example and the comparative example, the residual air amount and liquid spillage amount are the same as in the example. It can be seen that both the amount of liquid spillage and the amount of residual air are significantly reduced as compared with Comparative Examples 1 and 2. From the above analysis, the usefulness of the gas replacement method and apparatus according to the present invention was confirmed in comparison with the conventional gas replacement method and apparatus.

  INDUSTRIAL APPLICABILITY The present invention can be used as a gas replacement method and apparatus for replacing the residual gas by blowing a replacement gas into the head space of the contents-filled container, and particularly as a canned undercover gassing device, the amount of replacement gas, the amount of liquid spillage, the residual It is effective for reducing the amount of oxygen, but is not limited to gas replacement of can containers, but can also be applied as a gas replacement apparatus just before sealing a bottle-shaped container lid or a gas replacement apparatus before heat-sealing a cup-shaped container lid. It is.

It is a plane schematic diagram of the gas substitution apparatus concerning the embodiment of the present invention, and the substitution gas channel part is showing the plane section except for the finger part. It is the AA arrow line view. It is nozzle body sectional drawing which shows the relationship between the can body and can lid of the gas displacement apparatus which concerns on embodiment of this invention. It is a schematic diagram which shows the flow of the replacement gas at the time of gas replacement of the gas replacement apparatus which concerns on embodiment of this invention. FIG. 2 is a view corresponding to FIG. 1 in the case of a comb-shaped nozzle of a comparative example. It is a BB arrow line view of FIG. It is the schematic which shows the planar arrangement | positioning of the undercover gassing apparatus in a can winding apparatus. It is a graph which shows the relationship between the amount of residual air with respect to the displacement gas flow rate in an Example and the comparative example 2, and the amount of liquid spills. It is a graph which shows the relationship between the amount of residual air and the amount of liquid spills when the replacement gas flow rate in Examples and Comparative Examples 1 and 2 is constant.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Gas turret 2 Seaming turret 3 Arc-shaped recessed part (pocket) 4 Finger 5 Nozzle body 6 Vortex 10 Gas turret main body 11 Nozzle body 12 Replacement gas flow path 13 Wind direction adjusting plate 14 Replacement gas supply port 15 Main gas injection flow path 16 Sub Gas injection flow path 17 Intermediate sub gas injection flow path 20 Main gas injection flow 21 Sub gas injection flow 30 Can 31 Neck portion 33 Can lid 34 Chuck wall

Claims (5)

In a gas replacement method in which replacement gas is blown into the head space of a content-filled container to replace the remaining gas in the head space, the replacement gas flow blown from the replacement nozzle is directed outward from the container opening edge through the center of the opening. A main gas injection flow and a sub gas injection flow having a predetermined angle with respect to the center of the container opening and blowing symmetrically across the main gas injection flow. The gas is replaced by colliding the flow ,
A gas replacement method for a container, characterized in that an injection angle between sub gas injection flows which are blown symmetrically at a predetermined angle with respect to the main gas injection flow is 100 ° to 130 ° .   The gas replacement method is an undercover gassing method of a can winder, and the replacement gas flow has an opening in a height direction that is longer than the sum of the height of the can lid and 1/3 of the length of the can neck. The gas replacement method according to claim 1, wherein the gas is discharged from a replacement nozzle. In a gas replacement apparatus for replacing a residual gas by blowing a replacement gas into a head space of a content filling container, a main gas injection flow channel for blowing the replacement gas from the opening edge of the container to the outside through the center of the opening, and the container A sub-gas injection channel that blows replacement gas symmetrically with respect to the main gas injection flow with a predetermined angle with respect to the center of the opening and sandwiching the main gas injection channel; The opening of the gas injection channel has a predetermined length in the height direction so as to inject gas into the upper part of the container opening and the upper part of the container ,
The container gas replacement apparatus is characterized in that an angle formed by a direction in which the replacement gas opposed to the sub-gas injection flow path is formed is 100 ° to 130 ° . The gas displacement device is an undercover gassing device of a can winder, and the length of the displacement gas channel in the height direction is longer than the sum of the height of the can lid and the length of the can neck portion. The gas replacement device according to claim 3 . 5. The gas replacement according to claim 4 , wherein a pair of fingers provided on both sides of a pocket of the gas turret of the under cover gassing device is provided at an upper surface position of the sub gas injection flow path of the nozzle body. apparatus.

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