EP1056980B1 - Method for drying a hollow body and implementing device - Google Patents

Abstract

The invention concerns a method and a device for drying a hollow body (2), such as containers, container preforms, tubes or various conduits. The invention is characterized in that it consists in guiding (9) a drying agent (heat, dessicant, dry air . . . ) towards the assembly of surfaces to be dried, using means enabling said agent to pass entirely over all said surfaces.

Description

The invention relates to a method for drying bodies. hollow. It is particularly applicable, although not exclusively for drying containers between their manufacturing and filling, or even drying preforms or blanks for containers during processes container manufacturing. It still concerns a device for implementing the method.

By drying, within the meaning of the present invention, it is necessary hear a procedure for the disappearance of traces or a small volume of liquid remaining at inside or on the walls of a hollow body. Drying is therefore an operation which can follow for example draining or emptying a hollow body after a rinse cleaning or sterilization operation, having required the prior filling of the hollow body; he may also be to remove residues or traces of a sterilizing agent or any other processing agent previously deposited on the external or internal walls of the hollow body.

• le séchage de récipients ayant subi l'un des traitements susmentionnés entre leur fabrication et leur remplissage, tels que, par exemple, un nettoyage, un rinçage, une stérilisation entre la sortie de la chaíne de fabrication et l'entrée de la chaíne de remplissage, ou bien encore un nettoyage, un rinçage ou une stérilisation après une première utilisation, en vue d'une utilisation ultérieure;
• le séchage de préformes de récipients en matière plastique (PET, PEN,...) immédiatement avant leur introduction dans une machine de fabrication de récipients stériles;
• le séchage de tubes ou conduits divers.

Very particular applications of the invention are:

• the drying of containers having undergone one of the abovementioned treatments between their manufacture and their filling, such as, for example, cleaning, rinsing, sterilization between the outlet of the production line and the inlet of the filling chain , or alternatively a cleaning, rinsing or sterilization after a first use, with a view to later use;
• drying preforms of plastic containers (PET, PEN, ...) immediately before their introduction into a machine for manufacturing sterile containers;
• drying of various tubes or conduits.

Of course, the examples mentioned above are not restrictive, but simply give an overview of the field possible application of the invention.

Drying processes and corresponding devices previously known are not suitable in the sense that they do not not allow a distribution of the agent drying over the entire internal surface, again called inner wall, of the hollow body when it's basically that surface that needs to be dried; through elsewhere, the known devices are not "universal" in the sense that they don't allow body treatment hollow having distinct shapes from each other, or although still they are not suitable for the treatment of any type of material.

A known solution for drying hollow bodies consists in heat these to evaporate the remaining liquid found there.

This is the case of the solution described in document GB-A-1 396,565, which relates to a process of the type described in the preamble of claim 1 and which consists in heating the hollow body, in order to dry, thanks to a flame injected by a burner.

This solution is not suitable for drying containers in thermosensitive material, such as containers or their plastic plastic preforms (PET, PEN, ...) because the temperature required to achieve evaporation is likely to cause deterioration (deformation, modification of the physico-chemical properties) of containers.

In addition, it is not suitable for high rates treatment.

Another solution is to blow hot air into hollow bodies.

This solution does not allow correct drying with strong cadences, on the one hand; it is not suitable to certain forms of hollow bodies, on the other hand.

Indeed, it is not possible to obtain drying correct and fast, because the blowing of hot air leads the appearance of compression knots and bellies in the hollow body with, as a consequence, phenomena turbulent opposing a correct sweep, therefore a correct drying, inside the hollow body. In consequence, the hot air flow must be applied for a significant period of time so that all of the surfaces to be dried have been swept. This solution is therefore difficult to apply to certain types of materials heat sensitive since some areas will be exposed for a significant time to the hot air flow, which may cause deterioration.

This solution is not suitable for drying hollow bodies having particular shapes such as bottles or the bottles.

Indeed, the flow of hot air is blown in through the opening (the neck) of the hollow body which is small in diameter by compared to the other parts of the hollow body. Phenomenons above (knots and compression bellies) are amplified and it is very difficult to dry the inside of the shoulder of these hollow bodies, that is to say the part widening between the neck and the body.

The subject of the invention is therefore a method and a device which do not have one or the other disadvantages mentioned above, namely which allow: drying of the whole surface; a possibility of application, without significant modification of the device, in the event of change of hollow body to dry; an application to everything type of hollow body (bottles, jars, flasks, basins, tubes ...); an application to any type of material.

According to the invention, a method for drying hollow bodies, in particular containers or container preforms, in which a drying agent consists of a flame which is injected by a burner and is put into contact with the surfaces to be dried, is characterized in that that it includes the features of claim 1.

Thus, by training, that is to say by guiding the agent on surfaces, we get a correct distribution unlike devices where one projects or breathes the agent inside. A simple agent training, after its introduction, makes the process usable with any type of material; as will be explained later, the process can be implemented with a device relatively simple to use for any type of body hollow whatever their shape or size, and without the need to modify it significantly when the shape and / or dimensions of the body are changed.

Another advantage is that the agent training by a gas entrainment current allows drying to be carried out whatever the arrangement of the hollow body, that is to say whatever the position of its opening (top, bottom or other).

• la figure 1 est un schéma de principe d'un dispositif pour sécher des corps creux conformément à l'invention;
• la figure 2 est un schéma de principe d'un dispositif préféré;
• la figure 3 est un schéma d'une variante des dispositifs des figures 1 et 2 applicable au séchage de tubes ou de conduits.

Other advantages of the invention will appear on reading the description which follows, given with reference to the appended figures, in which:

• Figure 1 is a block diagram of a device for drying hollow bodies according to the invention;
• Figure 2 is a block diagram of a preferred device;
• Figure 3 is a diagram of a variant of the devices of Figures 1 and 2 applicable to the drying of tubes or conduits.

The device shown in Figure 1 includes a drying agent generator 1.

The drying agent can be a dry or hot gas, such as air, or any other suitable agent (desiccant by example).

In one implementation, where the agent is hot air, the generator 1 is a high heat generator temperature.

In a preferred embodiment, the drying agent is a flame and the generator 1 is then a burner.

As illustrated in Figure 1, the generator 1 is arranged outside the hollow body 2 (here a preform of container), near the opening of the latter, and the generator output is oriented so that the agent can be directed towards the inside of the hollow body.

In accordance with the example illustrated in FIG. 1 where the hollow body 2 is of the type open to only one of its ends (container, container preform for example), a tube 3 is introduced into the hollow body by its opening 4. One end 5 of the tube is near a area of the hollow body distal to the opening (the bottom area in the case of a container); the other end of the tube is located outside the container and is connected either directly, either through a conduit 6 to a suction source 7.

Preferably, as illustrated in the figure, the axis longitudinal of the tube 3 is aligned with that of the hollow body.

Furthermore, the outer section of the tube is significantly less than the inner section of the opening of the hollow body so that the drying agent can enter the hollow body through space device remaining between the tube and the opening of the hollow body.

For placing or removing the hollow body 2 relative to the device, means are provided allowing relative axial movement between the body hollow 2 and at least the tube 3.

Thus, in one implementation, at least the tube 3 is sliding in the axial direction (double arrow 8) to allow the establishment or removal of the hollow body 2 relative to the device. Thus, the hollow body 2 can be brought next to the device by simple translation lateral by erasing the tube from the body supply path hollow. It is thus possible to use, to ensure the installation of the hollow body, transfer systems known per se, such as gripper mechanisms transfer, mounted on articulated arms, or wheeled mechanisms or transfer trays comprising notches or cavities for guiding the hollow bodies.

Alternatively, it is envisaged that the establishment of the hollow body is made by subjecting it to a translation axial, the tube 3 remaining fixed.

In a variant, only the tube 3 is sliding. he therefore slides relative to the hollow body, and to the generator 1 when placing or removing the hollow body.

In a variant, it is the tube 3 and the generator 1 which are axially translated during placement or removal of the hollow body 2.

The opening 4 of the hollow body 2 is placed opposite the output of generator 1, without however coming into contact with it.

Preferably, when the drying takes place during a sterilization process, the device is kept in an atmosphere of sterile overpressure to prevent additional particles or dust do not penetrate in the hollow bodies to be sterilized. For this, means known are used, such as an isolation chamber under laminar flow of sterile air in which the device.

After the device (tube 3, generator 1) and the body hollows 2 have been put in correct relative position one by compared to each other, drying agent is generated by the generator 1. The aspiration generated by the means 7 suction through the tube 3 opening (at 5) to proximity to the bottom of the hollow body 2 creates a current of the drying agent which is then directed to inside the hollow body (arrows 9) and dries the internal surface of the hollow body.

As already mentioned, the drying agent used can be dry gas, desiccant, or heat.

The advantage of suction is that it not only allows agent training on all walls, but that it also allows its withdrawal when it is a desiccant.

Preferably, however, drying takes place in using heat: this is particularly advantageous when drying occurs during a process sterilization.

In this case, generator 1 is a heat generator: it can be constituted by a hot air nozzle with high temperature or by a burner. The heat or the flame is directed to port 4 and simultaneously suction is created in the hollow body to channel the flame or heat to the walls.

The use of a flame or a hot air generator is not not contraindicated for drying hollow bodies in heat-sensitive material, such as containers or container preforms of thermoplastic material.

Indeed, the time of exposure to heat is very low. Given the thermal inertia of the material, the directed hot air has only a purge function or for drying the hollow body.

However, when the hollow body to be dried is made of material thermosensitive, it is preferable to provide means to prevent a direct transfer between the output of the heat generator 1 (nozzle or burner) and the hollow body 2.

FIG. 2 illustrates a possible embodiment of a device with means for preventing transfer direct.

The means comprise a casing 10, made of material resistant to heat, cylindrical in the example illustrated, and open at one of its ends. The open end of the housing 10 is opposite the opening of the hollow body 2, here a container such as a bottle, without coming to its contact, on the one hand, to avoid a deterioration of the hollow body when made of heat-sensitive material and, on the other hand, allow good circulation of the heat. Tests have shown that a gap included between 0.1 mm and 5 mm allowed to obtain good results.

Furthermore, an orifice 11 is formed in the wall of the casing 10, and the output of generator 1 is directed to this orifice.

As shown in this figure 2, the tube 3 is straight and passes through a wall of the casing 10, for example the opposite one at the opening opposite the hollow body.

Alternatively, the tube could be bent and pass through the cylindrical wall.

When the device is in operation, the heat is directed towards the hollow body, not directly, but in passing through the housing 10.

Tests have also shown that the use of a device in accordance with that of FIG. 2, performs better than that of Figure 1 where the agent (heat or other) is directed directly to the hollow body.

Indeed, the casing 10 contributes to causing an effect directive on the agent.

This variant therefore constitutes an embodiment prefer.

In addition, when the agent is heat, it is desirable to provide additional means of protection of the opening of the hollow body, such as a protection plate 12 for the opening of the hollow body at least partially surrounding the casing 11 and disposed between the orifice 11 for passage of the hot air or the flame and the opening of the casing 10 on the hollow body side 2, as shown in this figure 2.

Preferably, as illustrated, the plate is extended by a peripheral rim more broadly covering the opening of the hollow body.

Preferably, the drying phase of the hollow body is carried out in two stages: a first where the drying (flame, or hot air, or other), is directed to the hollow body, the suction being active; and a second where the suction continues while the agent is no longer applied, so that all product residue wetting agent, whether gas, heat, or of desiccant, be removed as well as possible.

As an indication, we manage to dry out preforms of thermoplastic containers by applying a flame for 1 to 3 seconds at port 11 and continuing the suction between 2 and 6 seconds.

In FIG. 3, a diagram of the principle of the invention, when applied to body drying hollows open at two of their ends. This is for example the case of various tubes or conduits.

In this case, aspiration is carried out not using of a tube passing through the hollow body 13, and emerging at the end 14 of the hollow body opposite to that 15 near which is the generator 1 and, preferably, the casing 10,11,12, as shown: it is made at using a tube 16 located at the open end 14 of the body hollow opposite to that 13 near which the generator 1 and the casing 10. The tube 16 is connected to suction means 17.

The devices described in Figures 1, 2, 3 can make part of a larger treatment facility. They can be for example downstream or upstream of a machine for manufacturing hollow bodies such as tubes or containers that should be dried for example after cleaning or sterilization operation, either of body hollow after their manufacture, either preforms or blanks of hollow bodies before their manufacture.

They can still be present upstream of installations filling, or manufacturing / filling facilities, when The hollow bodies are containers.

Claims (12)

1. Method for drying hollow bodies (9) that includes at least one opening, of the kind consisting in bringing a flame injected via a burner into contact with the surfaces to be dried, characterized in that it consists in injecting the flame outside the hollow body near the said opening, and in causing, using suction means that act in the hollow body, in a region remote from the said opening, a gas stream driving the flame towards the inside of the hollow body so as to distribute the flame over all of the surfaces to be dried.
2. Method according to Claim 1, characterized in that the drying comprises two steps, namely a first step in which the flame is directed towards the hollow body, the suction being active, and a second step in which the suction continues although the flame is no longer applied.
3. Method according to Claim 2, characterized in that the flame is applied for 1 to 3 seconds.
4. Method according to either of Claims 2 and 3, characterized in that the suction continues for 2 to 6 seconds.
5. Device for implementing the method according to one of Claims 1 to 4, characterized in that it comprises means (1) for generating a flame outside the hollow body, means (3, 6, 7; 16, 17) for causing a gas stream driving the flame towards the internal surfaces of the hollow body (2; 13) when the latter is in place relative to the device, the said means for causing the gas stream consisting of suction means that act in the hollow body in a region remote from said opening.
6. Device according to Claim 5, characterized in that it includes a casing (10) placed on the outside of the hollow body (2; 13) near the opening of the latter, and provided: with an opening (11) facing the outlet of means (1) for generating the flame; with an open end having a shape and internal dimensions corresponding approximately to those of the internal opening of the hollow body.
7. Device according to either of Claims 5 and 6, characterized in that the means for causing the gas stream consist of a tube (3; 16) connected to a suction source (7; 17).
8. Device according to Claim 7, characterized in that, when the hollow body is in the form of a container, that is to say open at one of its ends and closed at the other, the tube (3) is introduced via the opening of the hollow body; the tube possesses one end that emerges near the bottom of the hollow body and its second end, outside the hollow body, is connected to the suction source (7).
9. Device according to Claim 8, characterized in that the tube (3) passes through a wall of the casing (10).
10. Device according to Claim 7, characterized in that, when the hollow body (13) is a tube or a pipe open at its two opposed ends, the suction is carried out by placing the suction tube (16) at the opposite end (14) of the hollow body from the end (15) where the flame is introduced.
11. Device according to one of Claims 5 to 10, characterized in that it is placed in a laminar flow of sterile gas, such as air.
12. Plant for manufacturing and/or for filling hollow bodies, characterized in that it includes a device according to one of Claims 5 to 11.

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