EP1693172A1

EP1693172A1 - Cork impregnation procedure and installation for putting it into practice

Info

Publication number: EP1693172A1
Application number: EP06075358A
Authority: EP
Inventors: José Luis Godoy Varo
Original assignee: Individual
Current assignee: Individual
Priority date: 2005-02-17
Filing date: 2006-02-16
Publication date: 2006-08-23
Anticipated expiration: 2026-02-16
Also published as: EP1693172B1; ES2355371T3; ATE485143T1; ES2259546A1; DE602006017610D1; PT1693172E; ES2259546B1

Abstract

The procedure includes one o more cycles, each comprising at least one of the following steps:

placing the cork inside a container (6) with walls having perforations or apertures, said container (6) being located inside a sealable tank (1);
closing said tank (1) and generating a controlled vacuum environment therein;
rotating said container (6); and
providing a liquid by spraying it on said cork from a pipe (36) having spraying nozzles (37) under a controlled jet pressure.

The installation comprises a tank (1) housing said container (6), means for rotating the container (6) I a controlled manner, means for generating a vacuum in the tank (1), means for providing heat energy and means for providing a liquid on the cork.

Description

Scope of the invention

This invention relates to a cork impregnation procedure.
The procedure is applicable to cork impregnation with chemical products for coating porosity and orifices of said cork. A second field of application consists in humidifying the cork, especially after decontamining and drying process.
The invention also describes an installation for putting the procedure into practice, in accordance with a possible exemplary embodiment.

Background

Cork impregnation methods have been known for many years.
Thus, British patent GB-A-10737 describes a method for impregnating cork with a heating or cooling stage during which the cork is deposited inside a rotating drum.
Patent ES-A-2006879 describes an apparatus for washing, bleaching and drying cork stoppers in a single cycle, describing an internal perforated drum for receiving corks to be treated, a plurality of pipes with fixed spray-nozzles spraying oxygenated water to wash the corks, together with fixed hot air impellers located underneath the rotating drum.
Patent ES-A-2067089 relates to an inert non-toxic surface coating for hot and cold lubrication and plastification of cork stoppers, in which stopper processing is carried out in normal open or closed drums.
Patent W02004/076607 describes a method for forming a film on articles susceptible to come into contact with beverages. Among these film-application processes, spraying is described.
The purpose of this invention is to provide an alternative procedure to those referred to in the cited background and which offers better adaptation to the characteristics of the product to be applied in relation to the cork.

Brief description of the invention

The invention consists of a cork impregnation procedure.
As is previously explained, said procedure is particularly suitable for providing a coating that forms a barrier against contamination contained in the cork, in order to carry out the washing, dyeing, lubricating or plastificating of the cork, or to humidify it with chemical products that do not permit the proliferation of bacteria, fungi or microorganisms, etc.
Said procedure is essentially comprised of the following stages:

placing the cork inside a container or drum with walls having perforations or apertures, said container being located inside a sealable tank or autoclave;
closing said tank and generating a controlled vacuum environment therein;
rotating said container; and
providing a liquid by spraying it on said cork under a controlled jet pressure.

It will be understood that the term "sprayed" in this descriptive specification covers any pneumatic, hydraulic, spray or atomisation aspersion system of a liquid with air.
Preferably, the liquid is provided by hydraulic atomisation operating under pressure values of about 20 bar or higher to ensure that the dissolved product deeply penetrates inside the cork porosity.
Alternatively, the product may be applied by air atomisation.
In accordance with common practice, at the start of the liquid provision the tank or autoclave connection to a pump or other vacuum-producing generator will be interrupted. However, in general, during the atomisation of the liquid inside the tank, a sub-atmospheric pressure value is still maintained in the inner environment. Alternatively, it is envisaged the liquid atomisation at a decreasing vacuum, which will increase contact with the impregnating material.
Said controlled vacuum environment provides pressure values inside the tank from 500 to 10 mbar, although pressure values inside the tank from 200 to 10 mbar have also been tested with satisfactory results.
Preferably, after completing a cycle, a forced pressurisation phase is carried out during which a pressure of less than six atmospheres (depending on application time) is attained inside the tank. In this way, improved penetration of the liquid or liquid containing dissolved substances into the cork mass is achieved.
For impregnation with chemical products, said liquid will contain the cited chemical products in solution or dispersion.
In accordance with the principles of this invention, the cork environment temperature is controlled during the process, by providing energy from the walls of the rotating container.
In accordance with a first exemplary embodiment, this energy is provided by radiation from a heat-transfer fluid.
Alternatively, the heat energy supply can be obtained by blowing a hot fluid towards the cork mass located inside the cited rotating container.
Moreover, in another alternative exemplary embodiment, the two previously described methods of providing heat energy are combined.
The possibility of an additional heat energy supply from an inner area of the cited container is also considered.
In order to enhance the results of the procedure being described, temperature control of the liquid containing the cited chemical products supplied from an outer tank is also contemplated.
It is therefore possible to supply said liquid with the chemical products in solution at a temperature equivalent to that of the environment of the cork inside the cited container, or above or below the same, by a predetermined magnitude.
After finalising one or more cycles of the proposed procedure, an additional drying stage is also envisaged (for example, thermal vacuum drying, providing hot air through a conduit associated with the cited container) for the cork inside said container, which characteristics will depend on the chemical product to be supplied. The purpose of this additional drying stage is to achieve better product fixing.
The installation for putting the referred procedure into practice will be explained in detail in the following description of an exemplary embodiment with reference to the accompanying drawings, which are merely illustrative and non-limitative.

Brief description of the drawings

Fig. 1 is a schematic elevation view in cross section of a tank with an open wall container for the treatment of cork in accordance with the principles of this invention.
Fig. 2 is a similarly schematic view in longitudinal elevation and section of the previous tank.

Detailed description of an exemplary embodiment

Referring to Figs. 1 and 2, these refer to an installation for cork impregnation consisting of an autoclave tank 1, with a substantially cylindrical shape, set in a horizontal position (other orientations, such as vertical are also possible). The cited autoclave tank 1 has an opening at one end and a cover or door 2 is mounted in such a movable manner that it can adopt an open position (not illustrated), in which the cover 2 is separated from the autoclave tank 1 opening in order to provide an access to the same, and a closed position (Fig.2), in which the cover 2 is coupled to the autoclave tank 1, sealing it hermetically. In order to mechanically perform autoclave tank 1 opening and closing operations, the cover is fixed to a motor 3 coupled to a cog 4 that meshed with a stationary rack 5. Operating motor 3 in one or the other directions will drive the cover 2 between the open and closed positions.
Attached to the cover 2 is a basket or container 6, with at least one loading and unloading door fitted with a moving panel that may be open for placing cork in the mentioned container 6 and to remove it, and closed to retain the cork inside the container 6. The container 6 including a loading/unloading door (not shown) is provided with an exterior wall with orifices or apertures that allow the liquid and/or steam to pass through. One end of the container 6 remote from the cover 2 is supported on wheels 9 designed to run along guides 8 installed inside along the length of the autoclave 1. Thus, when the motor 3 is operated to move the cover 2 in the autoclave tank 1 opening and closing operations, the container 6 is moved with the cover 2 so that it can be moved into and out of the autoclave tank 1. When the cover 2 is in the open position, the container 6 is completely outside the autoclave tank 1 and when the cover 2 is in the closed position (Fig.2), the container 6 is completely inside autoclave tank 1, which is then hermetically sealed.
Moreover, the ends of container 6 are mounted on bearings on the cover 2 and on a structure carrying the wheels 9 so that the container 6 is able to rotate with respect to a substantially horizontal shaft that is aligned with a central axis of the autoclave tank 1. A motor 10 is installed on an exterior part of the cover 2 and coupled to rotate the container 6 in both directions inside the autoclave tank 1.
Secured to an outer (or inner) side of the container 6 wall is a pipe 11 1 which forms a serpentine through which a heat-transfer fluid circulates. Ends of the mentioned pipe 11 are connected to a double-path rotating joint 12 mounted on the inner end of the container 6 shaft and said rotating joint 12, in turn, is connected via piping to inlet and outlet ports fixed to an exterior part of the cover 2.
Alternatively, (in an example not shown in the drawings) said basket or container can have one or more hoops welded to its perimeter, the purpose of which is that they fit into and are supported on freely rotating wheel coupled to a structure that bears the same container. In this way, said container possesses support points while it rotates and this provides greater rigidity, which is an especially significant aspect in the case of long containers.
In another exemplary embodiment, the walls of said container are at least partly made of said serpentine pipe 11, with suitably spaced sections.
As shown in Fig. 2, the installation includes a heat-transfer fluid tank 14, connected via a pipe to a boiler 15. Means of heating, for example, electric heating elements, are installed inside of said boiler 15. The boiler 15 has an inlet and an outlet that are connected via respective pipes to the mentioned inlet and outlet ports 13 on cover 2. One of said pipes includes a pump 16 to circulate the heat-transfer fluid from the tank 15 through the inlet door 13 and the rotating joint 12 towards the pipe 11, which forms a serpentine on the wall of container 6 and again through the rotating joint 12 and the outlet door 13 to the boiler 15 for reheating. The mentioned pipes that connect the boiler 15 to the inlet and outlet ports 13 have flexible or extendable portions 17 accommodating the movement of the cover 2.
In an upper area of the autoclave tank 1, there are several inlet and outlet ports 26 through which fluids can be added to the interior of the autoclave tank 1 or steam removed. As shown in Fig. 2, an outlet port 26a of said inlet and outlet ports 26 is connected via a pipe 40 to a vacuum pump 27 (preferably a liquid ring with or without a gas injector, to achieve vacuum pressure values inside within the range of the previously indicated values) driven by a motor 28 to produce a relatively low pressure inside the autoclave tank 1. A condenser 29 is installed at the vacuum pump 27 inlet to prevent steam coming from inside the autoclave tank 1 from entering the vacuum pump 27. The cited condenser 29 is not required if a liquid ring pump is employed given its characteristics, since such a pump would allow the handling of steam and gases without affecting its mechanism, although the maximum vacuum levels provided by these pumps are around 33 mbar, except when a gas injector is used, in which case lower values may be attained.
As can be seen in the figures, the spray device is installed in a fixed position inside container 6 for better spraying efficiency (in general consisting in atomisation under controlled pressure) of the cork contained therein. To this end, the motor 10 that rotates the container 6 is coupled to the shaft at one end of the container 6 by means of a belt transmission 34 in order to leave this end of the shaft free for the installation of a coupling 35 connected to a stationary pipe 36 fitted longitudinally in the upper section of the inside of container 6. The ends of container 6 are installed using bearings so that it rotates around said stationary pipe 36, which is fitted with a plurality of spray nozzles 37 distributed along the same. In the example shown in Fig.2, the coupling 35 of the stationary pipe 36 is connected by means of a pipe fitted with a flexible or extendable portion 38 to a spray liquid tank 39. Although not shown in the figure, the tank 39 is associated with means to regulate the temperature of the spray fluid or liquid in order to adjust it to the inner environmental conditions of the container 6 inside the tank 1. Pumping means associated with tank 39 for pumping the liquid into tank 1 will be also included when necessary.
In an alternative exemplary embodiment of the invention, in addition to pipe 11, which forms a heater serpentine 11, a second pipe (not shown in the figures) is also included in serpentine form and in this case with pass-through orifices that are preferably orientated towards the inside of the container and through which a fluid can be supplied, such as steam or pressurised hot air etc. A second rotating joint, similar to the already mentioned rotating joint 12, will be employed for this purpose. This second serpentine may eventually replace the first one or be used in combination with it.

Claims

A procedure for cork impregnation, characterised in that it comprises one or more cycles, each of which comprising at least one of the following steps:
- placing the cork inside a container or drum (6) with walls having perforations or apertures, said container (6) being located inside a sealable tank (1) or autoclave.

- closing said tank (1) and generating a controlled vacuum environment therein;

- rotating said container (6); and

- providing a liquid by spraying it on said cork under a controlled jet pressure.
A procedure in accordance with claim 1, characterised in that said provided liquid contains chemical products in solution or dispersion and in that a control of the provided liquid temperature is performed.
A procedure in accordance with claim 1, characterised in that during its execution a control of the temperature of the cork environment is performed by providing energy from the walls of the rotating container, said energy provision being performed by blowing a hot fluid.
A method in accordance with claim 3, characterised in that additional thermal energy is provided from an interior area of said container.
A procedure in accordance with claim 1, characterised in that said liquid provided by spraying is supplied at an temperature equivalent to or having a predetermined differential with respect to that of the environment of the cork loaded inside the container (6).
A procedure in accordance with claim 1, characterised in that said vacuum environment provides pressure values inside the tank (1) of between 500 and 10 mbar.
A procedure in accordance with claim 1, characterised in that after completing a cycle, a forced pressurisation phase is carried out reaching a pressure inside the tank (1) of less that six atmospheres, depending on the application time, while maintaining said tank (1) closed.
A procedure in accordance with claim 1, characterised in that during the provision of the liquid, the vacuum generation in tank (1) is interrupted.
A procedure in accordance with claim 1, characterised in that the provision of the liquid is carried out during a decreasing vacuum phase.
A procedure in accordance with claim 1, characterised in that it includes an additional cork drying stage inside said container (6).
A cork impregnation installation comprising:
- a sealed tank (1) or autoclave.

- a container or drum (6) with perforated walls for containing the cork, having at least one opening and a loading/unloading door able to retain the cork, and allowing fluids to pass through, the container (6) being supported in such a way that is able to rotate and oscillate in a controlled fashion inside said tank (1);

- means to provide a liquid by spraying it inside said container (6); and

- means for introducing and extracting said container (6) into and out of the tank (1),
characterised in that means for providing thermal energy are included, said means being associated with at least the walls of said container (6), and in that said sealed tank (1) is associated with a pipe (40) connected to at least one vacuum-generating pump (27) or other vacuum-generating device.
An installation in accordance with claim 11, characterised in that said energy providing means consist of a pipe (11) in the form of a serpentine extending along the wall of said container (6) through which a heat-transfer fluid is circulated, said heat-transfer fluid being externally heated and passed through a rotating joint (12) installed in one of the rotating supports of container (6).
An installation in accordance with claim 11, characterised in that said energy providing means consist of a pipe in the form of a serpentine extending along the wall of said container (6) through which a heat-transfer fluid is circulating, said heat-transfer fluid being externally heated and passed through a rotating joint installed in one of the rotating supports of container (6), with said pipe having a plurality of pass-through orifices orientated towards the inside of container (6).
An installation in accordance with claim 12 or 13, characterised in that it also includes a second pipe in the form of a serpentine with pass-through orifices orientated towards the inside of the container and externally connected to a source of heated fluid.
An installation in accordance with claim 12, characterised in that the walls of said container (6) are at least in part made of said pipe (11) with suitably spaced sections.
An installation in accordance with claim 11, characterised in that it comprises of a plurality of spray heads (37) defined along the length of a tubular pipe (36) orientated in such a manner that it extends longitudinally to the container (6) and is secured at its two ends by means of corresponding rotating joint arrangements that guarantee its immobility.
An installation in accordance with claim 11, characterised in that the rotating container (6) that contains the cork is coupled to a door (2) that closes the autoclave and in that a motor (10) is provided to rotate the container (6), said motor (10) being located on the outer part of said door (2), and in that the container (6) is provided with several outer reinforcement hoops associated with rolling elements for providing support inside the tank (1) walls.
An installation in accordance with claim 11, characterised in that a condenser (29) is fitted to the inlet pipe (40) of the vacuum pump (27) before the suction section thereof.