Method for operating a container treatment plant

Abstract

The invention relates to a method for operating a container treatment plant having a plurality of treatment modules (1) for treating containers (2) arranged within a common housing (7), wherein the treatment modules (1) each have a fluid supply (6) for introducing a treatment fluid into the containers (2), and wherein the fluid supplies (6) are connected to a common supply line (4). According to the invention, in a sterilization operation, a sterilization fluid is introduced into the housing (7) and, starting from the housing (7), flows through and sterilizes the fluid supplies (6), and wherein the sterilization fluid is withdrawn again via the common supply line (4).

Description

[0001] The present invention relates to a method for operating a container treatment plant which has a plurality of treatment modules for treating containers which are arranged within a common housing, wherein the treatment modules each have a fluid supply for introducing a treatment fluid into the containers and wherein the fluid supplies are connected to a common supply line.

[0002] The invention relates in particular to container treatment systems in the field of the food industry, in particular the beverage industry, wherein treatment means all activities that affect the containers in any way, provided that a treatment fluid is used for the treatment.

[0003] For example, the container treatment plant can be a filling plant in which the containers are filled with a product. This product can also be a liquid food, particularly a beverage, which is poured into the containers in the container treatment plant. In this case, the containers are, in particular, beverage bottles, e.g., made of glass or plastic, or beverage cans.

[0004] Alternatively, the container processing system can also be designed as a forming system, in which the containers are first formed into beverage bottles. This is typically done in blow molding or stretch blow molding systems, with the containers initially being in the form of so-called preforms.

[0005] Preforms are containers which are only finished in the area of ​​the container mouth with an external thread for receiving a closure cap and in which only the container body is then formed into a beverage bottle during blow forming or stretch blow forming. For this purpose, a treatment fluid, in particular a gaseous treatment fluid (e.g. compressed air), is introduced into the container, which applies internal pressure to it and presses the container body against a blow cavity. The blow cavity has the shape of the beverage bottle to be produced. In a stretch blow molding system, a so-called stretch rod is also provided, which causes the container body to be axially elongated along the container axis.

[0006] In order to enable such blow forming, the containers are usually made of a thermoplastic material, which is first heated within a heating device and softens in the process. The material is in particular polyethylene terephthalate (PET).

[0007] During blow forming or stretch blow forming, a liquid treatment fluid can also be introduced into the containers. This then primarily involves a filling material that is already intended for filling the containers. Accordingly, the containers are not only formed by introducing the treatment fluid but are also filled at the same time. Such a process is commonly referred to as a form-fill process. Regardless of the design of the container treatment system, it is customary to sterilize the fluid feeds and the shared feed line at certain intervals. In the context of the invention, sterilization is understood to mean a process that enables the destruction of germs and bacteria. Accordingly, the fluid feeds are not simply cleaned, which can only wash out germs or bacteria.Instead, a sterilization fluid is actively introduced, which is capable of killing the existing bacteria.

[0008] In order to be able to carry out appropriate sterilization, a distinction is made between a production operation and a sterilization operation, whereby no active treatment of the containers can take place during the sterilization operation, so that accordingly no containers are usually arranged within the container treatment plant.

[0009] From EP 2 388 126 B1, it is known that the common supply line in a blow molding system is connected to a sterilization device via a connecting line, through which a sterilization fluid is then introduced first into the common supply line and then, via a rotary union, into the individual fluid feeds. After sterilization, the common supply line can then be easily separated from the connecting line, so that a blow molding fluid can be introduced into the preforms again via the supply line when production begins.

[0010] Although such a design has proven particularly simple and effective, this type of process has the problem that only the piping system can be sterilized, while the outer surfaces of the blow molding modules must be sterilized separately. This particularly applies to surfaces of the blow molding modules that are in contact with the container. Even the outer surfaces of the fluid supply lines, which are relevant to production operations, are only exposed to a small amount of the sterilization fluid.

[0011] It should also be noted that the sterilization fluid is already largely consumed when it leaves the fluid supply lines, so that it can no longer be guaranteed that sufficient sterilization of the surfaces will be achieved after it leaves the fluid supply lines and enters the common enclosure.

[0012] Against this background, the object of the invention is to provide a method which enables a holistic sterilization of the treatment modules to a suitable extent during a sterilization operation.

[0013] The subject matter and solution of this problem is a method according to claim 1 and a container treatment plant according to claim 7.

[0014] According to the invention, it is therefore important that in a sterilization operation, instead of a sterilization fluid is introduced into the housing and, starting from the housing, flows through the fluid supplies and sterilizes it, and the sterilization fluid is withdrawn again via the common supply line.

[0015] In contrast to the method known from the prior art, the flow of the sterilization fluid is thus reversed, with a suitable amount of the sterilization fluid being first introduced into the housing and from there flowing first through the fluid inlets and only then through the supply line. This ensures that the sterilization fluid has a suitable concentration of an unused sterilizing agent, which can still effect sufficient sterilization within the housing and at the outlet of the fluid inlets. In principle, a combination of the two methods is also conceivable, with sterilization taking place against the flow direction of the treatment fluid in a first step according to the invention. Sterilization can then also take place in the flow direction of the treatment fluid.

[0016] According to a preferred embodiment, the container treatment plant is designed as a blow molding plant or stretch blow molding plant, in which containers in the form of preforms are formed into beverage bottles. The forming takes place either with a gaseous treatment fluid (e.g. compressed air) or with a liquid treatment fluid, which in this case is primarily a liquid filling material, in particular a foodstuff, e.g. a beverage (form-fill process). To enable such forming, the treatment modules each have a container receptacle designed as a blow mold. This blow mold usually consists of at least two blow mold halves, which are designed to be pivotable relative to one another and which together form a blow cavity corresponding to the shape of the beverage bottle to be produced.

[0017] When the blow cavity is open, a container in the form of a preform can be inserted, with the blow mold then being closed by pivoting the blow mold halves. A fluid supply is assigned to the container receptacle, through which, when the container is closed, the treatment fluid is introduced under pressure into the container to cause plastic deformation of the container. Typically, the fluid supply is formed on a valve device arranged above the container receptacle, so that the supply of the treatment fluid can be controlled accordingly via the valve device.

[0018] The at least one treatment module is usually arranged on a rotatably drivable carrier, so that the containers are treated as the carrier rotates. Such a configuration is also preferred for a filling system. In particular, a large number, e.g. 10 to 20 treatment modules, are arranged on the carrier, so that a large number of containers can be treated simultaneously. According to such a configuration, the treatment modules, including the fluid supplies and the container receptacle, are firmly mounted on the carrier, so that the treatment fluid is supplied to the containers in a rotating system. For this purpose, the fluid supplies are connected either directly or indirectly to a rotary feedthrough, which enables the treatment fluid to be transferred between a stationary line system and the rotating fluid supplies.According to such a design, the supply line is part of the fixed line system and connects to the rotary union at the end.

[0019] In order to enable a plastic deformation of the containers in a suitable manner in the first place, the container treatment plant can have a heating device which is arranged upstream of the at least one treatment module and in which the containers or the preforms are heated in order to soften the material, in particular PET.

[0020] Furthermore, the invention is particularly advantageous when not only the introduction of a sterile treatment fluid is desired, but also when the containers are already sterile during treatment or are sterilized during the treatment. In particular, the container treatment system can have a container sterilization device in which the containers are sterilized. Accordingly, a distinction must be made between a sterilization device according to the invention that sterilizes the line system, in particular the supply line and the fluid feeds, in a sterilization facility and a container sterilization device that sterilizes the containers in a production facility.

[0021] This container sterilization device is preferably arranged upstream of the at least one treatment module in the transport direction of the containers. In the case of a blow molding system, the container sterilization device can be arranged either upstream of the heating device or between the heating device and the at least one treatment module. Arranging it upstream of the heating device has the advantage that, in the case of sterilization using a container sterilization fluid, the container sterilization fluid is first introduced into the container sterilization device and then activated in the downstream heating device. The sterilizing agent is, in particular, hydrogen peroxide (H2O2), peracetic acid, steam, or mixtures thereof.Furthermore, it is also conceivable for the container sterilization device to be integrated into the heating device or into the treatment modules, so that sterilization occurs during heating or during blow molding, respectively. Instead of sterilization with a container sterilization fluid, sterilization of the containers by irradiation, particularly UV irradiation, is also possible.

[0022] A further development of the method provides that the supply line, at an end opposite the fluid supply, is subjected to a pressure that is lower than that of the housing. This naturally refers to the internal pressure of the housing. The housing is intended, in particular, to protect the containers during production. Accordingly, the housing is designed, in particular, in the form of a clean room and is suitably sealed against the environment. After the sterilization fluid has been introduced, the supply line can then be subjected to a reduced pressure or negative pressure, with the pressure difference between the housing and the end of the supply line being between 0.5 and 0.7 bar.

[0023] Furthermore, the enclosure preferably has an internal pressure between 0.9 bar and 1.5 bar, whereby this refers to an absolute pressure. Accordingly, the internal pressure in the enclosure essentially corresponds to atmospheric pressure or is at most slightly above atmospheric pressure to avoid placing unnecessary strain on the enclosure's structural integrity. Furthermore, the introduction of a comparatively large amount of sterilization fluid is necessary to achieve a sufficient concentration of the sterilizing agent within the enclosure.

[0024] In this context, it should be noted that the sterilization fluid is preferably a gaseous sterilization fluid, thus enabling good distribution within the enclosure. The sterilizing agent of the sterilization fluid can also be bound in gaseous form or in the form of an aerosol in the sterilization fluid. Accordingly, the sterilization fluid has a carrier fluid, into which the sterilizing agent is then admixed in the appropriate concentration ratio. The carrier fluid can, in particular, be compressed air. For example, it can be provided that during the sterilization operation, the sterilizing agent is present in the carrier fluid at a concentration between 300 ppm and 5000 ppm, preferably between 300 ppm and 4000 ppm, and in particular between 300 ppm and 1000 ppm. This information refers to the average concentration within the enclosure.

[0025] Assuming an internal pressure within the enclosure that is essentially in the range of atmospheric pressure, it becomes clear that the required pressure difference is preferably achieved by applying a negative pressure relative to atmospheric pressure at the end of the supply line. This can be achieved, for example, by a vacuum device, such as a suction pump. Alternatively, it is also possible to connect a vacuum reservoir to the supply line.

[0026] As previously explained, it is necessary to introduce a suitable amount of sterilization fluid into the enclosure. Based on typical enclosure sizes, the amount of sterilization fluid introduced is preferably between 0.5 and 20 Nm 3 / h. This refers to the previously mentioned concentrations of the sterilizing agent.

[0027] A further development of the invention provides that the sterilization fluid at least partially contains hydrogen peroxide (H2O2) or peracetic acid as a sterilizing agent. Hydrogen peroxide has proven particularly effective in achieving sterilization within a suitable timeframe. Alternatively, it is conceivable to use steam as the sterilizing fluid instead of hydrogen peroxide. In this case, the addition of a sterilizing agent would not be absolutely necessary. However, the handling of steam is complicated, especially within the scope of the method according to the invention, since the water can condense on the walls of the housing and on the system components, necessitating complex drying after sterilization. Furthermore, electronic components in particular can be damaged.

[0028] Furthermore, it is also known for the supply line to be connected to a filter device. This filter device serves to keep the treatment fluid as free of particles and germs as possible during production. However, this also means that the filter device must also be sterilized from time to time. The filter device is usually not mounted on the rotatable support but rather arranged upstream of the rotary feedthrough. The filter device can have one or more filter units arranged within a filter housing. During sterilization, these filter units must be flowed through with a sterilization fluid. The method according to the invention enables the sterilization fluid to flow through and sterilize not only the fluid supplies and the supply line but also at least one filter unit.The filter device is usually located between the supply line and the vacuum device or the vacuum reservoir.

[0029] The invention also relates to a container treatment system according to claim 7 for carrying out the method according to the invention, comprising a plurality of treatment modules for treating containers arranged within a common housing, wherein the treatment modules each have a fluid supply for introducing a treatment fluid into the containers, and wherein the fluid supplies are connected to a common supply line. The possible configurations of the container treatment system have already been explained in connection with the method according to the invention. Accordingly, the objective features already mentioned in the context of the method can also be readily transferred to the container treatment system itself, and vice versa.

[0030] According to the invention, the supply line is fluidically connected to a vacuum reservoir and / or to a vacuum generator at the end opposite the fluid supply.

[0031] The vacuum generator is, in particular, a suction pump. This can be driven, for example, by a simple electric motor.

[0032] A further development of the invention provides for a filter device to be arranged in a fluid-acting manner between the vacuum reservoir and / or the vacuum generator and the supply line. The filter device comprises, in particular, at least one filter unit arranged in a filter housing. The at least one filter unit can be designed as a sterile filter, a particle filter, or an activated carbon filter.

[0033] Furthermore, the treatment modules can be designed as blow molding modules or stretch blow molding modules, with the fluid feeds being provided for introducing a blow molding fluid into the containers for forming them into beverage bottles. In this case, the container treatment system is a blow molding system or stretch blow molding system.

[0034] The invention is explained in more detail below using an exemplary embodiment. The single figure shows a schematic representation of the container treatment plant according to the invention and the method according to the invention for operating this container treatment plant.

[0035] According to the figure, a container treatment system is provided, which is designed as a stretch blow molding system and accordingly has a plurality of treatment modules 1, which are designed as stretch blow molding modules. These treatment modules 1 have a blow molding cavity in which the containers 2 are received. The containers 2 used are so-called plastic preforms, which are formed into beverage bottles by introducing a blow molding fluid. Accordingly, these are containers 2 made of a thermoplastic material, in particular polyethylene terephthalate (PET).

[0036] For introducing the blowing fluid, a blowing device 3 is provided, which directs the blowing fluid in the form of compressed air via a supply line 4 to a rotary union 5, from which individual fluid supplies 6 branch off and which end in the individual treatment modules 1.

[0037] In addition, the individual treatment modules 1 and also the fluid feeds 6 are arranged at least in sections within a common housing 7, which is designed and constructed in the form of a clean room.

[0038] Typically, the container treatment system is sterilized weekly to reduce any germ or bacterial contamination within the piping system. This requires more than just simple cleaning. Actively destroying the bacteria is essential. This is achieved by using a sterilization fluid. This sterilization fluid is typically steam or a hydrogen peroxide-containing sterilization fluid, which must be passed through the piping system.

[0039] The present invention proposes that the sterilization fluid be introduced into the housing 7 from a sterilization device 8 and, from the housing 7, flow through the fluid supply lines 6 and be sterilized. The sterilization fluid is then withdrawn again via the common supply line 4.

[0040] In order to enable such a process, a vacuum device 9 in the form of a suction pump is connected to the feed line 4, wherein a switching valve 10 can be used to switch between a production operation in which the feed line 4 is connected to the blowing device 3 or a station operation by connection to the vacuum device 9.

[0041] By switching the switching valve 10 to the vacuum device 9, a vacuum is generated that is reduced compared to the internal pressure within the housing 7. In particular, this is a pressure difference of at least 0.5 bar. The internal pressure in the housing 7 is in particular between 0.9 and 1.5 bar and is thus within the range of or slightly above atmospheric pressure.

[0042] In addition, a filter device 11 is provided, which cleans the blowing fluid during production operation and which is also flowed through and sterilized by the sterilization fluid during sterilization operation.

[0043] The advantage of the procedure lies in the fact that not only the piping system can be sterilized but also external contact surfaces of the treatment modules 1.

[0044] At the same time, it is ensured that a sufficient concentration of unused sterilization fluid is still present, especially at the end of the fluid supply lines 6, which lead into the treatment modules 1, so that these areas can be sterilized in an adequate manner. List of reference symbols 1 treatment modules 2 containers 3 Blowing device 4 Supply line 5 Rotary union 6 fluid supplies 7 Enclosure 8 Sterilization device 9 Vacuum device 10 switching valve 11 Filter device QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] EP 2 388 126 B1

[0009]

Claims

[1] Method for operating a container treatment plant, which has a plurality of treatment modules (1) for treating containers (2) which are arranged within a common housing (7), wherein the treatment modules (1) each have a fluid supply (6) for introducing a treatment fluid into the containers (2) and wherein the fluid supplies (6) are connected to a common supply line (4), characterized by that in a sterilization operation, a sterilization fluid is introduced into the housing (7) and, starting from the housing (7), the fluid supplies (6) are flowed through and sterilized, and wherein the sterilization fluid is withdrawn again via the common supply line (4). [2] Method according to claim 1, characterized by that the supply line (4) is subjected to a pressure which is reduced compared to the housing (7) at an end opposite the fluid supplies (6). [3] Method according to one of the preceding claims, characterized by that the housing (7) has an internal pressure between 0.9 bar and 1.2 bar. [4] Method according to one of the preceding claims, characterized by that the sterilization fluid is present in an amount between 0.5 Nm 3 / h and 20 Nm 3 / h is introduced into the housing (7). [5] Method according to one of the preceding claims, characterized by that the sterilization medium is at least partially formed from hydrogen peroxide. [6] Method according to one of the preceding claims, characterized by that residues of the sterilization fluid are separated after withdrawal from the common supply line (4). [7] Container treatment plant for carrying out the method according to one of the preceding claims with a plurality of treatment modules (1) for treating containers (2), which are arranged within a common housing (7), wherein the treatment modules (1) each have a fluid supply (6) for introducing a treatment fluid into the containers (2) and wherein the fluid supplies (6) are connected to a common supply line (4), characterized by that the supply line (4) is fluidly connected to a vacuum reservoir and / or to a vacuum device (9) at the end opposite the fluid supplies (6). [8] Container treatment plant according to claim 7, characterized by that the treatment modules (1) are arranged on a movable, in particular rotatable, support, wherein the fluid feeds (6) are connected to the common feed line (4) via a rotary feedthrough (5). [9] Container treatment plant according to claim 7 or 8, characterized by that a filter device (11) is arranged in a fluid-acting manner between the vacuum reservoir and / or the vacuum device (9) and the supply line (4). [10] Container treatment plant according to one of claims 7 to 9, characterized by that the treatment modules (1) are designed as blow molding modules or stretch blow molding modules, wherein the fluid feeds (6) are provided to introduce a blow molding fluid into the containers (2) for forming into beverage bottles.

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