Machine and process for closing containers

Automatic machine for closing containers, including an automatic corking unit, a conveyor including an inlet section for feeding containers to be corked towards the automatic corking unit and an outlet section for moving apart the corked containers from the corking unit, an injection unit arranged upstream of the corking unit, arranged for injecting inert gas in the head portions of the containers to be corked, a casing defining a chamber which contains the injection unit and the corking unit and a feeding system of inert gas for maintaining within said chamber an inert gas atmosphere.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims benefit of European Patent Application Number 05425810.8, filed Nov. 16, 2005, which is herein incorporated by reference.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a machine and a process for closing containers, in particular for the corking of bottles.

The present invention is applicable to closing systems using caps of any type, such as for example corks, crown caps, screw caps, etc.

The present invention has been particularly developed for corking bottles of sparkling wines. The invention, however, is not limited to this specific application field and can be generally used for corking bottles and containers containing any kind of product.

In the field of the corking of wines, there is the problem of the oxygen of the air existing in the head portion of the bottles. The oxygen which remains trapped to the top of the bottleneck after the application of the cork causes an oxidation process which involves a loss of the organoleptic characteristics of the wine. This oxidation process is especially harmful in case of wines particularly valuable which should preferably maintain intact their characteristics also for many years.

To the wines intended for the bottling, in order to reduce the problems resulting from the oxidations and the development of aerobic bacteria caused by the oxygen existing in the head space of the bottle, it is a current practice to add sulfur dioxide or other chemical additives. Recently, the effects on the human health by the use of these sulfur-based compounds have been especially discussed. The regulations of some countries impose to show on the label of the product the presence of sulfur derivatives, and a possible evolution of the regulation in defense of the consumer in the near future could foresee the obligation of showing the quantity of sulfur compounds existing in the wine.

In view of the above, the producers of high quality wines have a great interest in developing corking processes which allow to reduce the use of the above chemical additives.

Corking systems which foresee the suction of the air existing in the head portions of the bottles before the application of the cork are already known.

Such systems can not be used, however, for the corking of sparkling wines as the suction of the air from the bottle would inevitably cause a loss of effervescence, which is one of the most important qualities of a valuable sparkling wine.

Therefore, for the sparkling wines the suction of air before the corking is not carried out, but sometimes the injection of an inert gas, typically nitrogen, is used before the corking. The injection systems of inert gas of the known type have however a very reduced efficiency concerning the reduction of the oxygen contained in the bottles after the corking.

The poor efficiency of the injection systems of inert gas of the known type does not allow a substantial reduction of the quantity of sulfur-based additives which must be added on bottling.

SUMMARY OF THE INVENTION

The aim of the present invention is to provide a corking machine and a process which allow to overcome the drawbacks above stated. In particular, the aim of the present invention is to provide a corking machine and a process which allow to obtain a substantial reduction of the oxygen existing in the bottles and which, in the particular case of corking of sparkling wines, do not involve a loss of carbon dioxide and therefore of the effervescence.

According to the present invention, such aim is attained by a machine and a corking process having the features forming the object of the claims.

DETAILED DESCRIPTION

Referring toFIGS. 1 and 2, an automatic bottling machine according to the present invention is shown by10. The machine10includes an automatic corking unit12which can be of any commercially available type. In particular, the corking unit12could be of the type suitable for applying corks, crown caps, screw caps, etc. The corking unit12is preferably of the carousel type, with a plurality of corking heads carried by a structure14rotating around a vertical axis16, but can also be monohead.

The structure and the functioning of the automatic corking unit12are not described in detail since, as previously said, the corking unit can be of any known type and its features are well known to a skilled in the art.

The bottling machine10includes a conveyor having an inlet section18for the feeding of bottles to be corked20towards the corking unit12and an outlet section22for the exit of the corked bottles24. The conveyor18,22is of the belt-type, usually employed in the bottling sector, which transports continuous arrays of bottles20,24vertically oriented.

In correspondence with the end part of the inlet section18of the conveyor, a screw-conveyor device26is placed, which spaces apart the bottles to be corked20and feeds them to a first transfer wheel28(FIG. 2) rotatable around a vertical axis and equipped with seats30for gripping the bottles20. The wheel28is associated with a curved-shaped stationary guide32which defines a guide path for the bottles20.

The bottling machine10includes an injection unit34arranged upstream of the corking unit12. The injection unit34, which can also be mono-head, picks up the bottles to be corked20from the wheel28and, after an injection of inert gas, sends the bottles to be corked to the corking unit12through a second transfer wheel36.

Referring to theFIG. 3, the injection unit34includes a rotatable support38which is carried in a rotatable way around a vertical axis40by a stationary support plane42of the machine10. The rotating support38carries a rotating central hub44to which a plurality of injection heads46, spaced apart in the circumferential direction, are connected. The injection heads46are connected to the central hub44through a disk structure48.

The rotating support38carries a plurality of bottle supports50, each of which is placed in correspondence with a respective injection head46. Each bottle support50includes a small plate52vertically moving, on which, in use, a respective bottle to be corked20is abutting.

Always referring to theFIG. 3, the injection unit34includes a distribution manifold54arranged co-axially to the rotating hub44. The distribution manifold54is connected through a stationary tube56to a source of pressure inert gas, shown by58. The inert gas can be any gas which is inert to the product contained in the bottles20. A typical inert gas can be, for example, nitrogen. Otherwise, other gases or gas mixtures free of oxygen can be used. The inert gas, for example nitrogen, is contained in high pressure cylinders equipped with pressure-reducer valves. The distribution manifold54feeds the flow of inert gas to the single injection heads46in the way that will be described hereinafter.

Referring to theFIG. 5, each injection head46includes an outer body60fixed with respect to the structure48. Inside the body60a sleeve62is slidably mounted in the vertical direction, which carries at its lower end a centering element64including a plastic body66with a conical centering surface68which is intended for abutting with a seal contact against the head surface of a bottle20. The sleeve62is elastically urged downwards by a compression coil spring70.

Each injection head46includes an injection tube72fixed with respect to the outer body60and extending within the sliding sleeve62. The injection tube72has an upper end connected to a feeding tube74of inert gas. The injection tube72ends with a cannula76whose lower end fits into the head portion of a bottle20. The lower end of the cannula76, in use, is arranged at a distance of about 20 mm from the upper level of the liquid contained in the bottle20.

Always referring toFIG. 5, the sliding sleeve62has an inner cavity78which constitutes a conduit for exiting the return gas flow. The conduit78communicates on the top with a chamber80formed at the top of the outer body60and communicating with a vent tube82.

InFIG. 5, the arrows show the direction of the inert gas flow in each injection head46. The delivery of the inert gas flow starts when the head portion of the bottle20is pressed against the conical surface68of the centering element64. The spring70ensures a pressure contact between the surface68and the upper end of the bottle20. The inert gas flows from the lower end of the cannula76and produces a return flow shown by the arrows directed upwards. This return flow removes the air contained in the head portions of the bottles20. The air and the inert gas leave the head portion of the bottle20and reach the chamber80through the conduit78. The return flow is drawn from the injection head46through the conduit82. By mere way of example, the injection pressure of the inert gas (gage pressure) is set on values in the order of 2,5 bars, with an average flow rate per nozzle in the order of 15 NI/1′. The duration of the injection of inert gas could be, for example, in the order of about 4 seconds per bottle. For the normal bottles of wine, the injection cannula76has an outer diameter in the order of 11 mm and an inner diameter of about 8,5 mm.

The injection of inert gas in the head portion of the bottle causes a substantial removal of the air (and therefore the oxygen) present in the head portion of the bottle. At the same time, a reduction of the oxygen dissolved in the liquid contained in the bottle is obtained as well. It is estimated that in a bottle of sparkling wine of 750 ml, whose headspace is equal to 25 ml (total capacity of the bottle of 775 ml) the enrichment in the total oxygen after the corking is about 3,0 mg/l. After the injection of inert gas in the injection unit according to the present invention, the quantity of total oxygen existing in the bottle is reduced on average to about 0,5 mg/l.

FIG. 4shows the distribution of the gas flows within the distribution manifold54. The distribution manifold54includes an inner steady hub84having a central channel86. Two concentric elements88,90are fixed with respect to the steady hub84and form an annular channel92for the distribution of the inert gas flow to the tubes74which, in turn, feed the inert gas flow to the various injection heads46. The element90is connected to the tube56which feeds to the manifold54the inert gas flow coming from the source58(FIG. 3).

The distribution manifold54includes a rotating body94integral with the rotating structure48and to which the tubes74for the feeding of the gas flow to the distribution heads46and the tubes82for the return gas flow are connected. The annular channel92is connected to the various tubes74through a first annular manifold96defined between the rotating body94and the element90. The tubes82of the return flow are connected to a second annular manifold98. The second annular manifold98is connected to the conduit86formed within the steady hub84, which serves for the exit of the return flow. The conduit86is connected through a joint100to a tube102(FIGS. 1 and 3) for the discharge of the return flow.

Referring to theFIGS. 1 and 2, the bottling machine10includes a casing104which forms a chamber106containing the corking unit12and the injection unit34. The casing104includes two extensions108,110which contain the sections18and22of the conveyor. The casing104is equipped with openings112,114for the inlet of the bottles to be corked20and for the outlet of the corked bottles24, respectively. Preferably, the openings112,114are equipped with respective plastic flexible curtains susceptible of bending in order to allow the passage of the bottles through the openings112,114.

The casing104is associated with a feeding system of inert gas suitable for maintaining in the chamber106an inert gas atmosphere. In the example shown in the figures, the feeding system of inert gas includes a tube150extending within the casing104and which is connected to the source of inert gas58through a conduit152. Preferably, in the casing104a device for measuring the oxygen concentration154is arranged, which controls the flow rate of inert gas introduced in the casing104through a solenoid valve156.

A second meter of the oxygen concentration158is preferably placed outside the casing104. The second meter158is foreseen as a security for the workers and switches on an alarm if the oxygen concentration falls below a pre-established threshold.

Preferably, the casing104is associated with a thermoregulation unit160, for the regulation of the gas temperature contained in the chamber106. The thermoregulation unit communicates with the chamber106through openings formed in the upper wall of the casing104.

The thermoregulation unit160includes a heat exchanger (cooler)162and a plurality of fans164,166. In the example shown inFIG. 1, a first fan draws a gas flow from the upper part of the casing104. The gas is cooled down by the heat exchanger162and reintroduced in the casing104by a second fan166. It can be foreseen a separation wall168extending within the chamber106for allowing the flow of cooled gas to reach most of the chamber106, by avoiding a “short circuit” between the flow drawn and the flow emitted from the thermoregulation unit.

The inert gas flow is introduced in the cabin, through the tube150, at a pressure of about 300 mmH2O, with a varying flow rate, on average in the order of 50 m3/h.

In the chamber106there is therefore an inert gas atmosphere with a minimum oxygen residue which can vary from 4% to 7%. This allows that, between the outlet from the injection unit34and the time in which the corking in the corking unit12is performed, an inlet of oxygen in the bottles to be corked is prevented. At the time in which the corking is performed, in the head portions of the bottles there is an inert gas atmosphere substantially free of oxygen.

The operations of inert gas injection and corking occur without ever performing a suction within the bottles. Therefore, the system according the present invention is particularly suitable for the corking of bottles of sparkling wines, wherein the corking in depression conditions would be particularly harmful as it would cause the emission of foam with a consequent loss of CO2and reduction of the effervescence.

The system according to the present invention allows a considerable reduction of the oxygen content existing in the bottles after the corking until the value of 80% (from 3 mg/l to 0,5 mg/l). Thanks to this, it is possible to remarkably reduce or eliminate at all the addition of sulfur dioxide or other chemical additives during the bottling step. From the qualitative point of view, it has been shown that the wines with a lower addition of additives are more healthy and, thanks to the decreasing of the total oxygen content in the bottle, more long-lived and softer sparkling wines could be obtained for their lower content of compounds with a bitter taste (phenolic compounds resulting from the oxidation).

Referring toFIGS. 1 and 2, according to a further advantageous feature of the present invention, it is possible to foreseen an inert gas screen in correspondence with the openings112,114which serve for the inlet and the outlet of the bottles from the volume in which the inert gas atmosphere is maintained. The inert gas screens are produced by nozzles132fed by the inert gas flow which exits from the injection unit34through the conduit102.

In case the transport of caps is carried out through an aspirator (for example for corks or the like), as the corking unit12is placed in an environment saturated with inert gas, also the flow produced by the aspirator can be used for making the screens of inert gas in correspondence with the openings112,114. The exhaust flow of the aspirator (not shown) is sent through a conduit136to a fan138feeds the nozzles132through conduits170. In this case, the exhaust flow of the injection unit34is fed to one or both the nozzles132together with the exhaust flow of the aspirator.

In the variant shown inFIG. 6, it is foreseen a heat exchanger172(cooler) downstream the fan138, for cooling down the gas flow sent to the nozzles132. In this variant, the thermoregulation unit160can be replaced by a simple air unit174free of cooler, which has only the task of circulating the gas flow in the volume106. In the variant ofFIG. 6it is also shown the use of two auxiliary nozzles176for feeding of inert gas in the extensions108,110of the casing104. The auxiliary nozzles176could of course be used also in the version ofFIG. 1.