阅读说明：本技术 具有离子交换装置的巴氏消毒设备和用于运行巴氏消毒设备的方法 (Pasteurization installation with ion exchange device and method for operating a pasteurization installation ) 是由 C·林德雷尔 R·孔钦 G·德穆兰 于 2017-10-27 设计创作，主要内容包括：本发明涉及一种巴氏消毒设备和一种用于运行巴氏消毒设备的方法。在巴氏消毒设备的运行中,在一个或多个处理区中,将经调温的处理液体,在处理区中将施加到填装有食品的容器外侧上。在至少一个循环回路中,将至少一部分处理液体又引回到处理区中,以便再利用。这里,处理液体的每单位时间经由所述至少一个循环回路引导的体积流的至少一个部分量被分流出来,以形成至少一个部分流,将所述部分流引导通过净化装置,接着将其重新引回到循环回路或处理区中。所述至少一个净化装置包括膜过滤装置和离子交换装置。(The invention relates to a pasteurization installation and to a method for operating a pasteurization installation. In operation of the pasteurization device, the tempered treatment liquid is applied to the outside of the containers filled with food in one or more treatment zones. In at least one circulation loop, at least a part of the treatment liquid is returned to the treatment zone for reuse. At least one partial flow of the volume flow of the treatment liquid guided per unit time via the at least one circulation circuit is branched off to form at least one partial flow, which is guided through the purification device and then returned into the circulation circuit or the treatment zone. The at least one purification device comprises a membrane filtration device and an ion exchange device.)

1. Method for operating a pasteurization installation (1), comprising: conveying the food-filled and closed containers (6) through one or more treatment zones (2), treating the containers (6) in the treatment zones (2) with a tempered, aqueous treatment liquid (4) by applying the treatment liquid (4) to the outer sides (5) of the containers (6),

wherein at least a part of the treatment liquid (4) from the treatment zone (2) is returned to the treatment zone (2) in at least one circulation circuit (11) for reuse,

at least one partial quantity of the volume flow of the treatment liquid (4) conducted per unit time via the at least one circulation circuit (11) is branched off to form at least one partial flow (19), the at least one partial flow (19) is filtered by means of a membrane filtration device (23) having a membrane with pores having a pore diameter of between 0.01 μm and 0.5 μm, whereby the membrane filtration device is suitable for carrying out microfiltration or ultrafiltration,

it is characterized in that the preparation method is characterized in that,

then removing dissolved ions from the at least one partial stream (19) by means of an ion exchange device (24) having at least one strongly acidic cation exchanger (32),

the at least one partial stream (19) is then returned to the circulation circuit (11) or the treatment zone (2).

2. Method according to claim 1, characterized in that the pH of the partial stream (19) is influenced with respect to the desired pH level by means of the at least one strongly acidic cation exchanger (32).

3. Method according to claim 1 or 2, characterized in that the at least one strongly acidic cation exchanger (32) is regenerated as a function of the change in the pH value of the partial stream (19).

4. The method as claimed in claim 1, characterized in that anions are removed from the partial stream (19) by means of at least one strongly basic anion exchanger (33).

5. Method according to claim 4, characterized in that the pH value of the partial stream (19) is influenced with respect to the desired pH value level by means of the at least one strongly basic anion exchanger (33).

6. A method according to claim 4 or 5, characterized in that the at least one strongly basic anion exchanger (33) is regenerated in dependence of the change in the pH value of the partial stream (19).

7. Method according to claim 1, characterized in that the content of dissolved ions in the partial stream (19) is monitored with a sensor before and after the ion exchange device (24), respectively.

8. Method according to claim 7, characterized in that the content of dissolved ions in the partial stream (19) is monitored before and after removal of ions by means of the ion exchange device (24), respectively, by measuring the pH value of the partial stream (19).

9. Method according to claim 1, characterized in that the partial quantity of the treatment liquid (4) which is branched off from the at least one circulation circuit (11) for forming the partial flow (19) is adjusted by means of a flow-rate adjustment device (35).

10. Method according to claim 1, characterized in that at least a part of the treatment liquid (4) is extracted from the partial stream (19) by means of at least one flow regulating means (38), guided through the ion exchange device (24) and then guided back again into the partial stream (19).

11. Method according to claim 10, characterized in that for each ion exchanger (32, 33) of the ion exchange device (24) the flow of the treatment liquid (4) through the ion exchanger (32, 33) is individually regulated by means of a flow regulating mechanism (38).

12. Method according to claim 1, characterized in that the partial stream (19) is additionally conducted through a liquid treatment device (42) comprising metal particles or metal braids containing copper and/or zinc before removing dissolved ions.

13. Method according to claim 1, characterized in that after removal of dissolved ions additional dissolved substances are removed from the partial stream (19) by means of an adsorption device (43).

14. Method according to claim 13, characterized in that the dissolved substances are removed from the partial stream (19) by means of an activated carbon filter.

15. Method according to claim 1, characterized in that the food in the container (6) is heated in one treatment zone (2) or gradually heated in a plurality of treatment zones (2), whereupon the food in the container is pasteurized in one treatment zone (2) or in a plurality of treatment zones (2), and thereafter the food in the container is cooled in one treatment zone (2) or gradually cooled in a plurality of treatment zones (2).

16. A method according to claim 1, characterized in that, if necessary, a partial volume flow of the treatment liquid (4) is conducted through a heat exchanger (46) of an air-cooled cooling tower (43).

17. Method according to claim 1, characterized in that the containers (6) with the metallic material are at least temporarily treated by means of the pasteurization device (1).

18. Method according to claim 1, characterized in that containers (6) with aluminium material are treated at least temporarily by means of the pasteurization device (1).

19. Pasteurization device (1) having:

one or more treatment zones (2) having a supply means (3) for applying a tempered treatment liquid (4) onto the outside (5) of the container (6),

a conveying device (7) for conveying the containers (6) through the treatment zone (2), and

at least one circulation circuit (11) for conducting the treatment liquid (4) out of the treatment zone (2) and for conducting at least a part of the conducted treatment liquid (4) back into the treatment zone (2),

at least one purification device (16) is provided, wherein the at least one purification device (16) is connected to a flow-technical line by means of a removal device (17) for removing a partial flow (19) of the treatment liquid (4) from the at least one circulation circuit (11), and wherein the at least one purification device (16) is connected to a flow-technical line by means of a return device (18) for returning the partial flow (19) into the circulation circuit (11) or the treatment zone (2),

the at least one purification device (16) comprises a membrane filtration device (23) for filtering the partial stream (19), the membrane filtration device having a membrane with pores having a pore diameter of between 0.01 μm and 0.5 μm, whereby the membrane filtration device is adapted for performing microfiltration or ultrafiltration,

characterized in that the at least one purification device (16) comprises, in terms of flow technology, an ion exchange device (24) downstream of the membrane filtration device (23), which has at least one strongly acidic cation exchanger (32).

20. Pasteurization plant according to claim 19, characterized in that the ion exchange device (24) has at least one strongly basic anion exchanger (33).

21. Pasteurization plant according to claim 19 or 20, characterized in that the ion exchange device (24) is flow-technically line-connected with a regeneration means (40, 41) for regenerating the ion exchanger (32, 33).

22. Pasteurization device according to claim 19, characterized in that sensor means for monitoring the content of dissolved ions in the partial flow (19) are provided in each case upstream and downstream of the ion exchange device (24) in terms of flow technology.

23. Pasteurization installation according to claim 22, characterized in that a pH sensor (34) is arranged in flow-technical fashion before and after the ion exchange device (24).

24. A pasteurization plant according to claim 20, characterized in that the ratio of the total ion exchange capacity of all existing strongly acidic cation exchangers (32) to the total ion exchange capacity of all existing strongly basic anion exchangers (33) is selected as required taking into account the desired pH value of the partial stream (19) or the treatment liquid (4).

25. Pasteurization plant according to claim 19, characterized in that the at least one purification device (16) is provided with a flow-rate regulation device (35).

26. Pasteurization device according to claim 19, characterized in that the ion exchange device (24) is arranged in the at least one purification device (16) in parallel to a throughflow line (39) for the partial flow (19) in terms of flow through at least one flow rate regulation means (38).

27. Pasteurization plant according to claim 26, characterized in that each ion exchanger (32, 33) of the ion exchange device (24) is assigned a flow rate regulating means (38).

28. Pasteurization plant according to claim 19, characterized in that the at least one purification device (16) comprises a further liquid treatment device (42) with metal particles or metal braids containing copper and/or zinc, which liquid treatment device (42) is arranged flow-technically between the membrane filtration device (23) and the ion exchange device (24).

29. Pasteurization plant according to claim 19, characterized in that the at least one purification device (16) comprises an adsorption device (43), which adsorption device (43) is arranged flow-technically after the ion exchange device (24).

30. Pasteurization plant according to claim 29, characterized in that the adsorption device (43) has an activated carbon filter (44).

31. A pasteurization plant according to claim 19, characterized in that the pasteurization plant comprises an air-cooled cooling tower (45) having a heat exchanger (46) through which the treatment liquid (4) can flow as required.

Technical Field

The invention relates to a pasteurization installation for foodstuffs filled in closed containers and to a method for operating a pasteurization installation.

Background

Pasteurization devices are used to allow long-term storage of food products by targeted tempering of the food products. The food product is typically heated to a higher temperature level and maintained at this higher temperature level for a certain duration of time in order to kill the surviving microorganisms. In many cases, the food is filled into containers and the containers are closed before pasteurization, and a tempered or heated treatment liquid is applied to the outside of the containers for tempering or pasteurization of the food. In this way, products that are ready for storage or sale can be provided.

So-called tunnel pasteurizers are generally used, in which containers that have already been filled with food and are closed are guided through one or more treatment zones and are sprinkled or sprayed with a tempered treatment liquid in the respective treatment zone. Aqueous treatment liquids are generally used, which are at least partially guided in a circulation around the treatment zone for reuse. This serves on the one hand to reduce the amount of fresh treatment liquid or fresh water that has to be supplied. On the other hand, the energy consumption required for tempering the treatment liquid can also be reduced in this way.

When the treatment liquid is conducted in a circulating manner in this way, in particular continuously or continuously, it is inevitable that impurities can enter the aqueous treatment liquid over time during operation of the installation. The source of such impurities may be, for example, ambient air, a cooling tower for cooling the treatment liquid as required, an operator, or, for example, a container or the contents of a container. For example, during the manufacture of the container, impurities, for example due to machining steps or the like, may remain on the outside of the container. It may also happen that, due to the slightly unsealed container, the food components enter the treatment liquid during the operation of the pasteurization device. Here, the leaktightness usually occurs in the region of the closure of the container, for example at a screw closure of a beverage bottle or at the closure of a beverage can.

In the past, measures have been proposed for removing impurities from the circulation-guided treatment liquid of a pasteurization installation. Measures for purification are proposed primarily with the aim of removing filterable and/or depositable particles. These measures are mainly related to the filtration of large particles, or the separation of large particles by sedimentation by gravity, see for example EP 2722089 a 1.

Furthermore, measures have already been proposed with which even fine to very fine particles, including microorganisms, can be removed from the treatment liquid guided in the circuit. Good results can be achieved in this respect, for example, by means of the measures proposed in WO 2016/100996 a1 based on the applicant. By the measures disclosed in WO 2016/100996 a1, it is possible in principle to obtain a haze-free, at least substantially sterile, treatment liquid.

However, if the treatment liquid is continuously or continuously circulated in the pasteurization installation, the incoming substances may be present in the form of dissolved ions or the incoming impurities may be dissolved over time from the treatment liquid into the form of ions. This is correlated to the corresponding chemical composition and other parameters of the treatment liquid. As a result, the dissolution of substances or impurities or the presence of dissolved ions may be exacerbated, for example, by an increase in temperature or by a corresponding pH value of the treatment liquid.

Many ions in the treatment liquid of a pasteurization apparatus are in principle undesirable. Examples include dissolved aluminum ions or ions of aluminum compounds, which can cause health damage in medical treatment. The same applies to other metal cations, for example heavy metal cations, but also to other substances present in ionic form. Such ions may increase in concentration in the treatment liquid over time while the treatment liquid is continuously, mainly guided in a circulation. Aluminum ions or aluminum compounds, for example, are frequently present because containers with aluminum, such as beverage cans with aluminum closures or made of aluminum, are treated several times in a pasteurization system.

In addition to health concerns, ions dissolved in the treatment liquid can also cause complications in the pasteurization process itself during the treatment of containers for the purpose of pasteurizing food products. Dissolved ions can only be removed conditionally or substantially not by membrane filtration alone. Until now, it has been preferred to use chemicals for adjusting and stabilizing the chemical composition of the treatment liquid or for removing undesired substances from the treatment liquid, such as, for example, corrosion inhibitors, water softeners or pH regulators, but also, of course, disinfectants or antimicrobial actives. This, however, leads in many cases to an equally undesirable introduction of said chemicals in large quantities into the treatment liquid, and these conditioning chemicals also lead to undesirable interactions, for example with the treated container itself. Furthermore, the continuous use of large amounts of chemicals is very expensive and measures for detecting the necessity of using such conditioning chemicals have to be provided.

There is therefore a need for further improvements in pasteurization plants with regard to the continuous purification of the treatment liquid which is conducted in a circuit or continuously reused.

Disclosure of Invention

The object of the present invention is to provide a method for operating a pasteurization installation and a pasteurization installation by means of which, during operation of the pasteurization installation, a treatment liquid can be provided which is as free as possible of impurities or undesired substances.

This object is achieved by the method and the pasteurization device according to the invention.

The method for operating a pasteurization installation comprises: the method comprises the steps of conveying the food-filled and closed containers through one or more treatment zones, and treating the containers in the treatment zones with a tempered, aqueous treatment liquid by applying said treatment liquid onto the outside of the containers. In this case, at least a part of the treatment liquid, preferably the majority of the treatment liquid or all of the treatment liquid from the treatment zone is returned to the treatment zone or one of the treatment zones in at least one circulation circuit for reuse. In this case, for example, it is possible to set: a volumetric flow of treatment liquid is introduced from one treatment zone into the other treatment zone via the circulation loop.

In the method, at least one partial flow of the respective volume flow of the treatment liquid, which is conducted per unit time via the at least one circulation circuit, is continuously branched off in order to form at least one partial flow of the treatment liquid. That is to say at least one partial flow branches off from at least one of the entire volumetric flows of the treatment liquid which are conducted via the circulation circuit or one of the circulation circuits.

Filtering the partial flow of the at least one partial flow by means of a membrane filtration device. Subsequently or subsequently, the dissolved ions are removed or exchanged from the at least one partial stream by means of an ion exchange device having at least one strongly acidic cation exchanger. After this, the at least one partial stream is again conducted back into the circulation circuit or the treatment zone. Preferably, the at least one branched partial stream is in turn introduced into the treatment liquid of the same circulation loop from which the partial stream branches off. This is in particular because the temperature level of the at least one partial stream corresponds at least substantially to the temperature level of the treatment liquid conducted in the circulation circuit, so that possible additional temperature regulation of the treatment liquid stream introduced into a treatment zone can be dispensed with.

It is thus possible to set: a partial stream is branched off from the circulation loop or one of the circulation loops. However, it is also possible to branch off a partial quantity of the volume flow of the treatment liquid per unit time which is conducted through the plurality of circulation circuits from each of the plurality of circulation circuits in order to form a plurality of partial flows. The individual circulation circuits can in this case be connected, for example, to the treatment zones by lines, so that a volume flow of treatment liquid is conducted from one treatment zone to the other via one circulation circuit.

By means of the method presented, undesired substances are continuously or constantly removed from the treatment liquid in the continuous operation of the pasteurization installation. This makes it possible, on the one hand, to provide as clean and sterile a treatment liquid as possible for the continuous operation of the pasteurization installation. Additionally, the concentration of undesirable ions can be kept as small as possible, or the concentration of undesirable ions (e.g., metal cations such as aluminum ions, or aluminum compounds present in ionic form) can be inhibited from continuously increasing as the treatment liquid is directed or reused on a continuous cycle. The metal cations can be removed effectively from the partial stream or streams, in particular by means of at least one strongly acidic cation exchanger of the ion exchange device. Advantageously, in this case it is further possible to at least significantly reduce the amount of chemicals used to adjust or stabilize the treatment liquid which is continuously reused or is conducted in the circuit. By continuously withdrawing and purifying the partial stream, it is furthermore possible, if appropriate, to dispense with further means for purifying the treatment liquid, such as settling devices or filter devices for separating large particles.

Furthermore, a favorable synergistic effect can be achieved by combined purification of the branched partial streams by means of the membrane filtration device and the ion exchange device. Dissolved nutrients for the microorganisms can be removed from the treatment liquid, for example by means of an ion exchange device, so that in this case at least the growth of the microorganisms can be limited. Further, this may have a positive effect on the membrane filtration. For example, the formation of biofilms on the filter membranes of the membrane filtration device or the occurrence of so-called biofouling of the filter membranes can be at least significantly reduced. In this case, the necessary membrane filtration capacity can in turn be reduced, or the time interval between possibly necessary cleaning or backwashing operations for the filtration membrane can be increased.

However, it is also possible, on the contrary, to provide the ion exchange device with a partial flow of the treatment liquid, which is at least largely freed of turbidity or coagulated particulate matter, by means of an upstream membrane filtration device. Only in this case is it possible to carry out the removal operation as smoothly and efficiently as possible by means of the ion exchange device. In this connection, it is particularly advantageous to filter out fine and very fine particles from the partial flow of the treatment liquid, since in this case potential blockages of the ion exchangers of the ion exchange device by the substances present in the form of small particles can be prevented and thus an effective throughflow of the treatment liquid through the ion exchange device can be achieved. In summary, it has been demonstrated that: the filtration by means of the membrane filtration device and the removal of ions by means of the ion exchange device complement each other excellently in terms of effective purification of the process liquid or of the branched-off partial stream.

It is also possible, in particular, to effectively remove metal cations from the partial stream of the treatment liquid by using at least one strongly acidic cation exchanger, instead of replacing them with other metal cations. Instead, the removed cations or metal cations may be replaced by H + ions, which are present in the aqueous treatment liquid solvated by water molecules according to common knowledge and are commonly referred to as oxonium ions or hydronium ions. Strongly acidic cation exchangers can, for example, comprise ion exchange matrices or ion exchange resins with (protonated) sulfonated acid groups as active exchanger groups.

In summary, undesired coagulated or particulate matter, including microorganisms as well as undesired dissolved ions, can be continuously removed from the treatment liquid by the proposed measures. It is further possible, in particular by removing ions by means of an ion exchange device, to also prevent undesired interactions of the treatment liquid or of ions dissolved therein with the treated container. For example, it has been demonstrated that: by the proposed measures, the occurrence of so-called black rust in the treatment of containers containing aluminum material can be effectively prevented. The formation of deposits, for example on the outside of the treated vessel, can likewise be suppressed by filtration and removal of dissolved ionic species.

In this way, the treatment liquid can be supplied to the treatment tank in a particularly simple manner, and the treatment liquid can be supplied to the treatment tank in a particularly simple manner, for example by means of a pump or a pump. Such mixing is effective, for example, in particular in pasteurization installations in which a volumetric flow of the treatment liquid is drawn off from the treatment zone and is again introduced into the respective other treatment zone via a circulation circuit. In other words, in this case, the individual volume flows of the treatment liquid are guided through the alternating circuit or are introduced into and removed from the alternating treatment zone over time in continuous operation, so that finally over time all the treatment liquid is guided through the purification device.

As has already been demonstrated, it is therefore generally not necessary to branch off a partial flow from the respective volume flow of each circulation circuit and to purify it, but rather a branching off and purification of a partial flow from a subset of the circulation circuits is sufficient to effectively purify the entire amount of treatment liquid in the pasteurization device. In many cases it is also entirely sufficient to branch off and purge a single partial flow from the single circulation circuit.

In a preferred embodiment of the method, further provision can be made for: the pH of at least one partial stream is influenced with respect to the desired pH level by means of at least one strongly acidic cation exchanger.

This can be achieved, for example, depending on the respective available ion exchange capacity of the strongly acidic cation exchanger. For example, it is possible to set: in order to influence the pH value of the partial stream, the flow through the at least one strongly acidic cation exchanger is adjusted or controlled. This will also be explained below. Cations, mostly metal cations, are continuously removed or removed from the partial stream by means of at least one strongly acidic cation exchanger during passage, and instead H + ions in the form of a solvent are output into the partial stream. In this case, the multiply charged cation (e.g., the solvent type Al3+ ion) is replaced by an H + ion equal in number to the charge of the cation. In summary, it is possible to reduce the partial flow and thus the pH of the entire treatment liquid as desired when a specific amount of treatment liquid per time unit flows through the at least one strongly acidic cation exchanger. Advantageously, the use of pH adjusting chemicals, such as acids or bases, to influence the pH of the treatment liquid can thereby be at least significantly reduced. During the trial it can be determined that: it may be advantageous for the aqueous treatment liquid of the pasteurization apparatus to be slightly acidic, for example with a pH value between 4 and 7. In this case, for example, the formation of so-called black rust on the aluminum material of the treated container can be prevented. Most generally, the pH of the treatment liquid may play a significant role in interacting with the correspondingly treated outer side of the container. Influencing the pH by means of an ion exchange device at the desired pH level of the treatment liquid may therefore be particularly advantageous for the present process.

In this connection, it can also be advantageous for the at least one strongly acidic cation exchanger to be regenerated as a function of the change in the pH value of the at least one partial stream or treatment liquid.

If it is determined, for example by pH measurement of the partial stream, that the pH can no longer be significantly reduced when the treatment liquid flows through the at least one cation exchanger, the at least one strongly acidic cation exchanger can be regenerated. In order to adjust or stabilize the pH value to the desired level, the treatment liquid may add a pH adjusting agent, such as an acid, as necessary as a substitute during regeneration of the at least one cation exchanger. If the lithium ion exchanger has a plurality of strongly acidic cation exchangers or if a plurality of ion exchangers is present, the addition of a pH regulator as an alternative can be dispensed with if necessary. By regeneration, it is now possible to provide sufficient ion exchange capacity for the cation exchanger.

In an embodiment, it is also possible to provide: the anions are removed or exchanged from the at least one partial stream by means of at least one strongly basic anion exchanger.

In this way, undesired anions can also be removed or removed from at least one partial stream of the treatment liquid.

In this case, it is also possible to further set: the pH of the at least one partial stream is influenced with respect to the desired pH level by means of the at least one strongly basic anion exchanger.

For example, it is again possible to set: in order to influence the pH value of the partial stream, the flow rate through the at least one strongly basic anion exchanger is adjusted or controlled. In principle, the respective numbers and exchange capacities of the strongly acidic cation exchangers and of the strongly basic anion exchangers can be selected or adjusted according to the respective desired pH level of the treatment liquid, as will also be explained. As has been shown, in the case of aqueous treatment liquids for pasteurization installations, a pH value of less than 8, in particular between 4 and 7, can be advantageous, for example, in order to suppress the formation of so-called black rust on the aluminum material of the treated container. On the other hand, by influencing the pH level of the treatment liquid by means of at least one cation exchanger and/or at least one anion exchanger, for example, an excessive decrease in pH can be prevented. In this case, for example, the aluminum material of the container can be prevented from being solvated or solubilized by the treatment liquid.

Embodiments which may also be advantageous in this respect are the following: regenerating the at least one strongly basic anion exchanger in dependence on a change in the pH value of the at least one partial stream.

The regeneration of the at least one strongly basic anion exchanger can be carried out, for example, in the following cases: the pH of the partial stream is significantly or excessively reduced during the flow through the ion exchange device, as determined on the basis of the measurement of the pH of the at least one partial stream. This may indicate that the anion exchanger has insufficient capacity of the ion exchanger. By regeneration, the strongly basic anion exchanger can in turn be provided with sufficient available ion exchange capacity.

In an embodiment, it can be provided that: the content of dissolved ions in the partial stream is monitored with sensors before and after the ion exchange device, respectively.

In this way, on the one hand, the ion exchange process can be monitored. However, the purity or quality of the aqueous treatment liquid can in principle also be monitored by monitoring the content of dissolved ions in the partial stream by means of sensors. For monitoring the ion content with a sensor, for example, conductivity sensors which are arranged in flow technology before and after the ion exchanger can be used.

However, it may also be expedient to monitor the content or concentration of dissolved ions in the at least one partial stream by measuring the pH of the at least one partial stream before and after the removal of ions by means of the ion exchange device, respectively.

In this case, the content of dissolved ions in the treatment liquid can also be deduced, since the pH of the partial stream after passing through the ion exchange device is directly related to the amount of dissolved ions in the treatment liquid. This applies in particular if the respective currently available ion exchange capacities of all existing strongly acidic cation exchangers and strongly basic anion exchangers of the ion exchange unit or of one of the ion exchange units are at least approximately known. Particularly advantageous possibilities in this case are: the ion content or mass of the aqueous treatment liquid can be deduced by means of a similar simple pH measurement. This measure can of course be used effectively in particular if: the respective available ion exchange capacity of all existing strongly acidic cation exchangers is not equal to the respective available ion exchange capacity of all existing strongly basic anion exchangers, or the ion exchange unit has for example no strongly basic anion exchanger at all. In principle, the following applies in this case: the more ions are dissolved in the treatment liquid, the more significantly the pH can be influenced or changed by means of the ion exchange device.

In general, one advantageous embodiment of the method may be: at least one partial quantity of the treatment liquid branched off for forming the at least one partial stream is regulated by means of a flow regulator.

This measure makes it possible to specifically influence or determine the amount of treatment liquid which branches off from the circuit in order to form the at least one partial flow. In this case, the respective partial amount of the treatment liquid can be adapted to the degree of contamination of the treatment liquid. This relates both to filterable, granular or coagulated substances and to undesirable ions which have dissolved in the treatment liquid. Furthermore, a control possibility is also provided in this case in order to influence the pH value of the partial flow or thus also the pH value of the treatment liquid towards the respective desired level. This is related to the ratio of the respective available ion exchange capacities of the existing strongly acidic cation exchangers and strongly basic anion exchangers. If the partial stream branched off from the circulation circuit is conducted, for example, through an ion exchange device having a strongly acidic cation exchange capacity which is higher than the strongly basic anion exchange capacity, the pH level of the partial stream or of the treatment liquid can be further reduced by increasing the number of the partial streams branched off to form the partial stream, i.e. increasing the volume flow of the partial stream.

However, it may also be advantageous to remove a portion of the treatment liquid from the at least one branched partial stream by means of at least one flow rate regulating device, to guide it through the ion exchange device and then to guide it back again into the at least one partial stream.

In this case, in particular, a further control possibility is provided for influencing the amount of dissolved ions removed from the partial stream. Furthermore, the pH of the partial stream can also be influenced in a targeted manner with regard to the desired pH level of the partial stream or of the treatment liquid by this measure.

It may furthermore also be expedient for the flow rate of the treatment liquid to be adjusted individually for each ion exchanger of the ion exchange unit by means of a corresponding flow rate adjustment mechanism.

The possibility of controlling the ion exchanger can be improved even further by this measure. In particular, the pH of the partial stream can be influenced more precisely in view of the desired level by this measure, since the release of solvated H + ions and/or hydronium ions can be specifically set or controlled.

In a further development of the method, it can be provided that: the at least one partial stream is additionally conducted through a liquid treatment device having metal particles or metal braids containing copper and/or zinc before the dissolved ions are removed.

With such a liquid treatment device, spontaneous oxidation reactions and/or reduction reactions of specific substances dissolved in the treatment liquid can be triggered. This depends on the respective standard potential of the dissolved substance, compared to the standard potential of copper or zinc at the respective given parameter, such as the pH value of the treated liquid. In this way, precious metal cations, such as heavy metal ions, iron ions, etc., can be separated from the partial flow with relatively simple and cost-effective liquid treatment devices (e.g., in comparison with copper and/or zinc). This is advantageous in turn for the efficiency of the downstream ion exchange device, since the ions which have been removed or separated off by means of the liquid treatment device no longer have to be removed from the partial stream by means of the ion exchange device or do not compete in ion exchange with other dissolved ions in the partial stream. The available ion exchange capacity of the ion exchanger of the ion exchange device may thus provide for the removal or removal of otherwise undesired, easily soluble ions, such as aluminum ions or ions of aluminum compounds, which are not removable by means of the liquid treatment device. In this case the efficiency of the purification of the partial stream can be improved even further. Furthermore, substances which inhibit the growth of microorganisms can be formed in the partial stream by spontaneous redox reactions in the liquid treatment apparatus.

However, it may also be expedient to remove additional dissolved substances from the at least one partial stream by means of an adsorption device after removal of the dissolved ions.

For example, it may be advantageous to remove dissolved substances from the at least one partial stream by means of an activated carbon filter.

By this measure, in addition to undesired dissolved ions, further undesired, in particular uncharged or non-ionized, substances can be removed from the at least one partial stream.

In principle, an advantageous embodiment of the method can consist in heating the food in the container in one treatment zone or gradually in a plurality of treatment zones, in subsequently pasteurizing the food in the container in one treatment zone or in a plurality of treatment zones and then in cooling the food in the container in one treatment zone or gradually in a plurality of treatment zones.

In this way, a particularly protected pasteurization process can be provided for the food product, since large temperature jumps can be avoided by the tempered treatment liquid. Furthermore, a uniform tempering of the food in the respective container can be provided in this way.

A further advantageous embodiment of the method can consist in that, as required, part of the volume flow of the treatment liquid is conducted through a heat exchanger of an air-cooled cooling tower.

The efficiency of the purification of the treatment liquid can be further increased by this measure as well. This is particularly because impurities can be prevented from being brought into the process liquid by or in the air-cooled cooling tower. Such air-cooled cooling towers are often required to cool a portion of the process liquid, which in turn may be used to cool the vessel, for example after pasteurization.

Since in most cases a cooling tower with a large cooling capacity is required, impurities are introduced in very large quantities in conventional cooling towers without heat exchangers.

Finally, it is also possible to set: containers with metallic material, in particular containers with aluminum material, are treated at least temporarily or temporarily by means of the pasteurization device.

In this case, the variety of containers to be treated by means of the pasteurization device can be further increased. In particular, it may be a very thin-walled container whose properties based on aluminum or aluminum alloys are still very suitable for preserving or warehousing food products which can be preserved for a long time. Containers with aluminum materials are challenging in many respects in the pasteurization process. On the one hand, aluminum components may undesirably enter the treatment liquid during the pasteurization treatment and may be dissolved by the treatment liquid. Furthermore, containers with aluminum are particularly susceptible to attack by surface chemical and/or physical changes that may be caused by the treatment liquid itself. This relates, for example, to the black rust already mentioned. Aluminum materials, for example, are commonly found in container closures. However, most containers are also made of predominantly aluminum, for example cans for holding food products which can be stored for a long time or, for example, beverage cans.

The object of the present invention is also achieved by providing a pasteurization apparatus for food products filled in closed containers.

The pasteurization apparatus has: one or more treatment zones having a guide mechanism for applying a tempered treatment liquid onto the outside of the container; and a transport device for transporting the containers through the treatment zone. Furthermore, the pasteurization device has at least one circulation circuit for removing the treatment liquid from the treatment zone and returning at least a part of the removed treatment liquid into the treatment zone or one of the treatment zones.

At least one purification device is provided, which is connected to the extraction means for extracting a partial flow of the treatment liquid from the at least one circulation circuit and which is connected to the return means for returning the partial flow into the circulation circuit or the treatment zone in a flow-technical manner. The at least one purification device comprises a membrane filtration device for filtering the withdrawn partial stream. Furthermore, the at least one purification device comprises, in terms of flow technology, an ion exchange device downstream of the membrane filtration device, which ion exchange device has at least one strongly acidic cation exchanger.

In order to flow the extracted fraction through the membrane filtration device and the ion exchange device, the at least one purification device comprises a guiding mechanism. The at least one purification device can preferably be configured selectively with respect to the circulation circuit such as to be blockable or flowable through via at least one blocking mechanism. The membrane filtration device can, for example, comprise one or more filtration modules or filtration units which, in the operation of the pasteurization installation, are used for the extracted or branched partial stream or a part of the branched partial stream to pass through.

By means of the features given, a pasteurization device can be provided for food products filled in closed containers, in which as large a portion as possible of the aqueous treatment liquid can be continuously reused. In particular, with the features given, means are provided for effectively cleaning the treatment liquid guided in the circulation circuit or circuits. The membrane filtration device allows for efficient removal of coagulated or particulate matter from the process liquid in such a situation. Undesired dissolved ions, for example solvated aluminum ions or ionically present aluminum compounds, can be removed or removed from the treatment liquid by means of the ion exchange device. In this case, the ion exchanger can also be prevented from becoming clogged with particulate matter in a cooperative manner by a membrane filter device which is arranged upstream of the ion exchanger in terms of flow technology. In addition, on the basis of the specified features, additional means for purifying the treatment liquid, such as settling devices or filter devices for separating large particles, can be dispensed with during operation of the pasteurization device.

The at least one purification device is fluidically connected to the circulation circuit line via an extraction means. The extraction mechanism can in principle have a simple distribution element, for example a T-piece, which can divert a partial flow from the circulation circuit. After this, a guide element, for example a line, can be provided for the partial flow of the treatment liquid branching off from the circuit to flow through the at least one purification device, i.e. through the membrane filtration device and then through the ion exchange device. The branched and purified partial stream can then be returned via a return means, for example a line, into the circulation circuit or into the treatment zone. Further advantageous elements, in particular means for regulating the amount of treatment liquid withdrawn from the circulation circuit, will be described further on. In principle, it is also possible to connect a plurality of purification devices via the extraction means in each case in flow-technical line connection with one circulation circuit or one of a plurality of circulation circuits of the pasteurization installation.

Furthermore, by using at least one strongly acidic cation exchanger, specific metal cations can be removed efficiently from the branched partial streams of the treatment liquid during operation of the pasteurization device, rather than being replaced by other metal cations. Alternatively, the removed cation or metal cation may be replaced by solvated H + ions. The strongly acidic cation exchanger may include, for example, an ion exchange matrix or an ion exchange resin having a sulfonic acid group as an active group. Furthermore, it is also possible to influence the pH of the branched partial stream with respect to the desired pH level of the partial stream by means of the at least one strongly acidic cation exchanger of the ion exchange device. It is advantageous here that the use of pH-adjusting chemicals, such as acids or bases, for influencing the pH of the treatment liquid can be at least significantly reduced.

Other advantages which are achieved by the features of the pasteurization installation given are already mentioned in the description of the method for operating the installation. Therefore, a repetitive description will be omitted herein.

It can furthermore be provided that the ion exchange device comprises at least one strongly basic anion exchanger.

By means of this feature, undesirable anions can also be removed or stripped from the branched partial flow of the treatment liquid during operation of the pasteurization device. In addition, the pH of the branched partial stream can also be influenced with respect to the desired pH level by means of the at least one strongly basic anion exchanger. Strongly basic anion exchangers can, for example, comprise ion exchange matrices or ion exchange resins having quaternary ammonium groups as active groups.

In an advantageous embodiment, it can be provided that the ion exchanger device is fluidically connected to at least one regeneration device for regenerating the ion exchanger.

In this way, both the at least one strongly acidic cation exchanger and the at least one strongly basic anion exchanger can be regenerated as required in order to be able to provide a sufficient usable ion exchange capacity or in order to be able to influence the pH of the branched partial stream accordingly with respect to the desired pH level by means of the ion exchange device.

In a further embodiment, it can be advantageous if sensor devices for monitoring the content of dissolved ions in the partial flow are arranged in each case fluidically upstream and downstream of the ion exchange device.

In this way, on the one hand, the ion exchange process can be monitored. However, the purity or quality of the aqueous process fluid can also be monitored in principle by means of sensor-based monitoring of the content of dissolved ions in the partial flow. For monitoring the ion content, for example, conductivity sensors can be arranged in each case fluidically upstream and downstream of the ion exchanger.

In a preferred embodiment, it can be provided that a pH sensor is provided in each case upstream and downstream of the ion exchanger in terms of flow.

By means of these pH sensors, changes in the pH of the branched partial flow of the treatment liquid due to the ion exchange device can be detected during operation of the pasteurization device. It is advantageous here that the purity or the content of the ions dissolved in the treatment liquid can be inferred further on the basis of the monitoring of the pH value.

Further, an embodiment of the pasteurization device in which the ratio/relationship of the total ion exchange capacity of all strongly acidic cation exchangers present to the total ion exchange capacity of all strongly basic anion exchangers present is selected as desired with regard to the desired pH value of the treatment liquid may also be suitable.

In this way, an effective measure for influencing the pH of the branched partial stream with respect to the respectively desired pH level can be provided during operation of the pasteurization device. Further, it is advantageously possible to at least significantly reduce the amount of pH adjusting chemicals based on the influence on the pH by means of the ion exchange device. It has been proven in practice that weak acid levels of the treatment liquid, for example an average pH value between 4 and 7, may be advantageous for the treatment of the outside of the container. This may be suitable, for example, in order to prevent the formation of so-called black rust on the aluminum material on the container to be treated. Accordingly, the total ion exchange capacity of all strongly acidic cation exchangers present is selected to be greater than the total ion exchange capacity of all strongly basic anion exchangers present.

In a further development of the pasteurization device, it can be provided that the at least one cleaning device is assigned a flow rate control device.

By means of this feature, means can be provided for the targeted control of the withdrawal of the partial flow from the volume flow of the treatment liquid guided in the circulation circuit for the operation of the pasteurization device. In this way, the respective branched-off, at least partial quantity of the treatment liquid is adapted, for example, to the respective degree of contamination of the treatment liquid. This is not only a filterable single or coagulated substance, but also undesirable, dissolved ions in the process liquid. Furthermore, a control possibility is also thereby achieved in order to influence the pH value of the partial flow or thus of the treatment liquid, respectively, also in the desired horizontal direction. This is related to the ratio of the respectively available ion exchange capacities of the strongly acidic cation exchanger and of the strongly basic anion exchanger present. The flow regulating device may, for example, comprise a flow regulating means in fluidic engineering, for example a continuously or steplessly adjustable flow valve.

A further development can also be advantageous in which the ion exchange device is arranged in the at least one cleaning device by means of at least one flow rate regulating means in parallel with the throughflow line for the partial flow in terms of flow.

In this way, a further control possibility is provided for the operation of the pasteurization device, in particular for influencing the amount of dissolved ions removed from the partial flow. In addition, the pH of the partial flow can be influenced in a targeted manner in respect of the desired pH level of the partial flow or of the treatment liquid by means of the device during operation. The flow control mechanism can in turn be formed, for example, by a manually or automatically controlled flow control device in fluidic technology.

However, it is also possible to provide a flow rate control device for each ion exchanger of the exemplary exchange device.

Thereby, the flow rate can be individually controlled or adjusted by each ion exchanger of the ion exchange device. In particular, this feature provides a means for influencing the pH value of the partial stream even more precisely at the desired level, since the release of solvent H + ions and/or hydroxide ions can be set or controlled in a targeted and efficient manner during operation of the pasteurization device.

Furthermore, an embodiment of the pasteurization device can be advantageous, wherein the at least one cleaning device comprises a further liquid treatment device comprising a metal braid or metal particles with copper and/or zinc, which is fluidically arranged between the membrane filtration device and the ion exchange device.

With such a liquid treatment device, a defined spontaneous redox reaction of the substances dissolved in the treatment liquid can be triggered during operation of the pasteurization installation. Thereby, noble metal cations, such as heavy metal ions, iron ions, etc., are separated from the extracted partial stream, for example in comparison to copper and/or zinc. This is advantageous in turn for the efficiency of the following ion exchange device, since the ions which have already been removed or separated by means of the liquid treatment device do not have to be removed from the partial stream by means of the ion exchange device or, with regard to ion exchange, do not compete with other dissolved ions in the partial stream. The available ion exchange capacity of the ion exchanger of the ion exchange device is thus advantageously provided for removing or removing other undesired dissolved ions, such as aluminum ions or ions of aluminum compounds, which cannot be removed by means of the liquid treatment device.

Furthermore, it can be provided that the at least one cleaning device has an adsorption device which is arranged fluidically downstream of the ion exchange device.

It can then be provided that the adsorption device has an activated carbon filter.

In this way, means are provided by which, in addition to undesired, dissolved ions, also other undesired, in particular uncharged or non-ionized, substances can be removed from the partial flow of the treatment fluid or the partial flow withdrawn from the circulation circuit.

In order to further improve the pasteurization installation, it can finally also be provided that the pasteurization installation has an air-cooled cooling tower with a heat exchanger which can be selectively blocked or selectively passed through by the treatment liquid with respect to a guide element provided for guiding the treatment liquid.

Also by this feature, the cleaning efficiency of the treatment liquid can be further improved. This is because, in particular, during operation of the pasteurization installation, contaminants can be prevented from entering the treatment liquid via or in the air-cooled cooling tower. Such air-cooled cooling towers are often required in pasteurization plants for cooling a part of the process liquid, which cooled process liquid can be used, for example, in turn for cooling the containers after pasteurization has been completed. Due to the high cooling capacity of such cooling towers, which is generally required here, the ingress of contaminants can be very large in conventional cooling towers without heat exchangers.

Drawings

For a better understanding of the invention, it is explained in detail with the aid of the following figures.

In each case in a clearly simplified schematic representation:

FIG. 1 shows a schematic view of an embodiment of a pasteurization apparatus;

FIG. 2 shows a schematic view of an embodiment of a purification device of a pasteurization installation;

fig. 3 shows a schematic view of a further embodiment of a pasteurization device in part.

Detailed Description

It is first pointed out that in the differently described embodiments identical parts are provided with the same reference numerals or the same component names, wherein the disclosure contained in the entire description can be reasonably transferred to identical parts having the same reference numerals or the same component names. The positional references selected in the description, such as upper, lower, lateral, etc., also relate to the currently described and illustrated figures and can also be transferred to new positions in the event of a change in position.

Fig. 1 schematically shows an embodiment of a pasteurization device 1. The pasteurization device 1 comprises one or more treatment zones 2 with a supply device 3 for applying a treatment liquid 4 onto the outer side 5 of a container 6. In the exemplary embodiment according to fig. 1, 5 treatment zones 2 are shown by way of example, wherein it is per se understood that more or fewer treatment zones 2 can also be provided according to the specific requirements and design of the pasteurization device 1.

In operation of the pasteurization device 1, the pasteurization of the food product is carried out in that the container 6 is filled with the food product beforehand and the container 6 is closed. The treatment of the containers 6 filled with food and closed is carried out in the respective treatment zones 2 by applying an aqueous treatment liquid 4 onto the outside of the containers 6 by means of said supply means 3. The supply means 3 of the respective treatment zone 2 can be formed, for example, by spray means of the spray head or nozzle type or, in general, by means for distributing the treatment liquid in the respective treatment zone 2. In this way, the tempered aqueous treatment liquid 4 is applied to the outside 5 of the container 6, as a result of which the container 6 and thus the food product filled into the container 6 can be tempered and pasteurized in a targeted manner. In principle, it can be provided here that containers 6 with metallic material, in particular containers 6 with aluminum material, are treated at least temporarily by means of the pasteurization device 1.

A conveying device 7 is provided for conveying the containers 6 through the treatment zone 2. In the embodiment shown in fig. 1, the conveying device 7 comprises two driven conveyor belts 8, by means of which the containers 6 filled with food and closed are conveyed in two layers through the treatment zone 2 in operation of the pasteurization device 1. This can take place, for example, from left to right in the transport direction 9 indicated by an arrow in fig. 1.

In the operation of the pasteurization device 1, it can be provided, for example, that the food in the containers 6 is first heated in one treatment zone 2 or in a plurality of treatment zones 2. In the exemplary embodiment shown in fig. 1, the food or containers 6 can be heated gradually, for example, in two treatment zones 2 shown on the left. After heating, the food products can be pasteurized in the treatment zone 2 or in a plurality of treatment zones 2, for example by supplying a tempered treatment liquid 4 suitable for pasteurization into the treatment zone 2 shown in the middle of fig. 1. After this, the food or containers 6 can be cooled again in the treatment zone 2 or in a plurality of treatment zones 2. The gradual cooling by supplying the treatment liquid 4 with a temperature which is respectively suitable for cooling the container 6 can be carried out, for example, in two treatment zones 2 shown on the right in fig. 1.

That is to say, it can be provided, for example, that the food is heated in the treatment zone 2 which is arranged first in the conveying direction 9 and that the food is further heated in the treatment zone 2 which is arranged subsequently in the conveying direction 9. In the treatment zones 2 arranged subsequently in the conveying direction 9, the food can then be pasteurized by applying a treatment liquid 4 having a particularly high temperature level, for example between 70 ℃ and 110 ℃, onto the outer side 5 of the container 6. In the two treatment zones 2 arranged downstream in the transport direction 9, the food products or containers 6 can be cooled in a targeted manner again by means of the correspondingly tempered, relatively cold treatment liquid 4. This is advantageous, mainly because it is thereby possible to pasteurize the food as protected as possible, in particular because the food is not damaged by the tempering itself.

After the tempered treatment liquid 4 has been applied to the outer side 5 of the container 6 in the treatment zones 2, it can be collected in the lower bottom region 10 of the respective treatment zone 2 and again conducted out of the respective treatment zone 2. In order to remove the treatment liquid 4 from the treatment region 2 and to return at least a portion of the removed treatment liquid 4 to one of the treatment regions 2 or one of the treatment regions 2, the pasteurization device 1 comprises at least one recirculation circuit 11. In operation of the pasteurization device 1, at least a part of the treatment liquid 4, preferably a majority of the treatment liquid 4 or the entire treatment liquid 4, is then returned from the treatment zone 2 for reuse in the at least one circulation circuit 11 into a treatment zone 2.

As can be seen from the exemplary embodiment shown in fig. 1, it can be provided, for example, that the treatment liquid 4 is withdrawn from one treatment zone 2 via a circulation circuit 11 and is supplied to the other treatment zone 2. In the embodiment shown, the treatment liquid 4 can be supplied, for example, from the treatment zone 2 shown on the far left to the treatment zone 2 shown on the far right via a circulation circuit 11. Conversely, the treatment liquid 4 can be supplied, for example, from the treatment zone 2 shown on the far right to the treatment zone 2 shown on the far left for heating the containers 6 or the food products via a circulation circuit 11. This may be desirable primarily because the treatment liquid 4 is cooled or heated during application or application to the container 6, respectively. By means of said cooling or heating, the treatment liquid 4 from the respective one treatment zone 2 can thus have a temperature level which is favorable for the other treatment zone 2. On the other hand, however, it may be expedient for the treatment liquid 4 from a treatment zone 2 to be returned via a circulation circuit 11 into the same treatment zone 2, as is shown with respect to the treatment zone 2 shown in the middle in fig. 1, which is provided for pasteurizing the food products.

In order to convey or to conduct a corresponding volume flow of the treatment liquid 4 in the one or more circulation circuits 11, a conveying device 12, for example a pump, can be provided in each case, as is shown in fig. 1. Furthermore, it is also possible for the pasteurization device 1 to have a device 13 for removing a portion of the treatment liquid 4 from the circulation circuit 11, for example for taking samples, and also a device 14 for supplying substances, for example fresh treatment liquid 4, for example fresh water or chemicals. Such means 13, 14 can be formed, for example, by lines which are provided for supplying and discharging the treatment liquid 4 into and out of a collector or the like, or the means 13, 14 can be fluidically connected in line for the purpose of tempering the treatment liquid by means of a heating and/or cooling device. Fig. 1 shows, by way of example, a heating device 15, for example a steam heater or a heat pump, which heating device 15 is fluidically connected by means of a line 13, 14 to the circulation circuit 11 for returning the treatment liquid 4 into the treatment zone 2 shown in the middle. In this way, the treatment liquid for the circulation circuit 11 can be heated to a temperature level which is correspondingly required for the pasteurization of the food product.

In operation of the pasteurization device 1, impurities or undesired substances can enter the aqueous treatment liquid over time as a result of the treatment liquid 4 being continuously conducted through the circulation circuit 11 or the treatment liquid 4 being continuously reused. In order to continuously remove the undesired substances or contaminants from the treatment liquid 4, at least one purification device 16 is provided. The at least one purification device 16 is fluidically connected to an extraction means 17 for extracting a partial stream 19 of the treatment liquid 4 from the at least one circulation circuit 11. Furthermore, the at least one purification device 16 is fluidically connected to a return device 18 for returning the extracted partial stream 19 into the circulation circuit 11 or into the treatment zone 2. In operation of the pasteurization device 1, at least one partial quantity of the volume flow of the treatment liquid 4 guided per unit time through the at least one circulation circuit 11 is thus diverted to form at least one partial flow 19, as is illustrated in fig. 1 by the arrows.

In the exemplary embodiment shown in fig. 1, two purification devices 16 are shown by way of example, which purification devices 16 are each fluidically connected to a different circulation circuit 11. Of course, only one purification device 16 can be provided or the pasteurization device 1 can also comprise more than two purification devices 16. The number of purification devices 16 and the purification capacity can be selected and determined here in each case, in particular taking into account the specifications and the processing capacity of the respective pasteurization installation 1. In addition, it is possible in any case for a plurality of purification devices 16 to be fluidically connected to one circulation circuit 11 or to one of a plurality of circulation circuits 11 via an extraction means 17.

The extraction device 17 can in principle have a simple distribution element, for example a T-piece 20, which effects a diversion of the partial flow 19 from the circulation circuit 11, as is schematically illustrated in fig. 1. The return device 18 can, for example, have a conduit line, via which the purified partial stream 19 can be supplied to the treatment zone 2, as is shown, for example, in fig. 1. In the case of a pressure loss at the at least one purification device 16 being taken into account or compensated for, it is also possible, instead of the embodiment shown in fig. 1, to return the partial flow 19 into the line of the circuit 11, for example via a further T-piece. In addition, further elements, such as a control device 21 and/or a shut-off mechanism 22, can be provided in order to be able to influence or adjust the partial quantity of the treatment liquid 4, which is diverted, for example, to form the partial flow 19 or is withdrawn from the volume flow in the circulation circuit 11, and/or in order to be able to shut off the purification device 16 as required relative to the circulation circuit. Examples of such further elements are further elucidated with the aid of fig. 2.

As also shown in fig. 1, the at least one purification device 16 comprises a membrane filtration device 23 for filtering the extracted partial stream 19. Furthermore, the at least one purification device 16 comprises, downstream of the membrane filtration device 23 in terms of flow technology, an ion exchange device 24, which ion exchange device 24 has at least one strongly acidic cation exchanger. A guide device 25 is provided for guiding the at least one branched or extracted partial stream 19 through the at least one purification device 16.

In this way, during operation of the pasteurization installation 1, the at least one partial stream 19 extracted or diverted from the circulation circuit 11 can be filtered by means of the membrane filtration device 23, and the dissolved ions can then be removed from the at least one partial stream 19 by means of the ion exchange device 24 having at least one strongly acidic cation exchanger. The at least one partial stream 19 thus purified is then fed back to the recirculation circuit 11 or the treatment zone 2 via the return device 18. The at least one branched partial stream 19 is preferably fed back to the treatment liquid 4 of the circuit 11 from which it is extracted, as is also shown in fig. 1. This is therefore particularly advantageous, since the temperature level of the at least one partial stream 19 corresponds at least substantially to the temperature level of the treatment liquid 4 conducted in the circulation circuit 11.

In this way, during operation of the pasteurization device 1, undesired substances can be continuously or continuously removed from the treatment liquid 4. On the one hand, therefore, as far as possible no turbid and sterile process liquid 4 can be provided for continuous operation of the pasteurization device 1. Additionally, the concentration of undesired ions, for example metal cations such as aluminum ions or aluminum compounds present in ionic form, can be kept as low as possible.

Furthermore, it can be provided that, during operation of the pasteurization device 1, the PH of the partial stream is influenced by at least one strongly acidic cation exchanger of the ion exchange device 24 in respect of the desired PH level, since the cations removed from the partial stream 19 pass through the H of the solvent⁺And (4) ion replacement.

Fig. 2 shows a further advantageous embodiment of the pasteurization installation 1 or an embodiment of the method. In fig. 2, the same reference numerals or component numerals as in fig. 1 above are used for the same components. To avoid unnecessary repetition, reference is made to or referred to the detailed description above in fig. 1.

As shown in fig. 2, the partial flow 19 of the treatment liquid branched off from the circulation circuit 11 is first guided or guided through a membrane filtration device 23. The membrane filter device 23 of the purification device 16 can have a plurality of filter modules 26, four filter modules 26 being shown purely by way of example in fig. 2. The number of filter modules 26 and the filter capacity of the filter modules 26 can each be selected in accordance with the desired degree of contamination and/or in adaptation to the volume of the treatment liquid which is generally conducted through the pasteurization device 1 during operation. In principle, the filter modules 26 of the membrane filter arrangement 23 can be arranged in the membrane filter arrangement 23 in any desired manner, for example in series one behind the other in terms of flow. In the exemplary embodiment shown in fig. 2, the filter modules 26 are arranged fluidically in parallel to one another, so that a partial quantity of the partial flow 19 can be conducted through or past the filter modules 26.

The design of the individual filter modules 26 can in principle also be selected at will, provided that the tempered aqueous treatment liquid can be filtered thereby. The filtration module 26 may, for example, have a plurality of hollow fiber membranes, which may be arranged in the retentate space 27 on the supply side. The hollow fiber membrane may have pores with a pore diameter of between 0.01 μm and 0.5 μm, for example, so as to be suitable for microfiltration or ultrafiltration. The respective open ends of the hollow fiber membranes of the filter module 26 can be inserted into a sealing device 28, so that the open ends or the inner cavities of the hollow fibers open into a filtrate or permeate space 29 of the filter module 26. The sealing means 28 can here sealingly separate the retentate space 27 from the permeate space 29, so that the at least one partial stream 19 of the aqueous treatment liquid can only pass from the retentate space 27 of the filtration module 26 into the permeate space 27 by passing through the hollow fiber membrane walls from outside the hollow fiber membranes into the hollow fiber lumens. The at least one partial stream 19 is now filtered and the particulate or coagulated impurities are retained on the retentate side.

As further shown in fig. 2, the filter modules 26 of the membrane filtration device 23 can be connected, as required, to a feed line for the backwash liquid 30 on the permeate or filtrate side and to a discharge line 31 on the retentate or supply side, respectively, so as to be blockable or able to flow through. This makes it possible to flush the filter modules 26 of the membrane filter device 23 with a counter current while reversing the direction of flow through the filter modules 26 in order to clean the filter membranes, for example hollow fiber membranes. The filter residue can be removed from the filter membrane on the retentate side, for example, in this way. In this case, for example, it can be provided that all filter modules 26 of the membrane filter arrangement 23 are cleaned together. Alternatively, it is also possible to connect the filter module groups or even each filter module 26 individually selectively in a blockable or flow-through manner to the upstream flushing liquid source 30 and the outflow opening 31, as is also shown in fig. 2. As the counter-current flushing liquid, for example, clean fresh water can be used, to which a chemical cleaning agent can be added if necessary. Additionally, the filter membrane can also be purged with a gas around the retentate side in order to assist the purification in the case of a back-flushing or to prevent the formation of filter residues.

As shown in fig. 2, an ion exchanger 24 is fluidically provided in the purification device 16 downstream of the membrane filtration device 23. The ion exchange device 24 has at least one strongly acidic cation exchanger 32. In the exemplary embodiment according to fig. 2, the ion exchange device 24 has two cation exchangers 32. As already described, the pH of the partial stream 19 is influenced in the desired pH level by means of the cation exchanger 32 during operation of the pasteurization device 1. The strongly acidic cation exchanger 32 can, for example, comprise an ion exchange matrix or an ion exchange resin having sulfonic acid groups as active groups.

As also shown in fig. 2, however, it is also possible for the ion exchanger device 24 to have at least one strongly basic anion exchanger 33. In operation of the pasteurization device 1, undesired anions can thus also be removed from the at least one diverted partial stream 19 by means of the at least one strongly basic anion exchanger 33. Strongly basic anion exchangers can, for example, comprise ion exchange matrices or ion exchange resins having quaternary ammonium groups as active groups. In operation of the pasteurization device 1, the pH of the at least one partial stream 19 can be influenced with respect to a desired pH level by means of at least one strongly basic anion exchanger. The influence on the pH value of at least one partial stream 19 can be achieved, for example, by adjusting the flow rate of the treatment liquid through the ion exchangers 32, 33 and/or through the entire ion exchange device 24, as will be explained in more detail below.

In principle, the ratio/relationship of the total ion exchange capacity of all strong-acid cation exchangers 32 present to the total ion exchange capacity of all strong-base anion exchangers 33 present can be selected as required with regard to the desired pH value of the at least one partial stream 19 or of the treatment liquid, in order to set it specifically to influence the pH value of the at least one partial stream 19. The pH of the at least one partial stream 19 is preferably influenced in the direction of or at a low acidity level. For example, an average pH value of between 4 and 7 of the treatment liquid during operation of the pasteurization device 1 can be advantageous for the treatment of the outside of the container. This is for example the case for preventing the formation of so-called black rust on aluminium material on the treated containerMay be suitable. Accordingly, the total ion exchange capacity of all strongly acidic cation exchangers 32 present is selected to be greater than the total ion exchange capacity of all strongly basic anion exchangers 33 present. This is of course a choice given to a sufficient total ion exchange capacity for the effective removal of undesired dissolved ions from the at least one partial stream 19.

In an advantageous method embodiment, it is suitable for the content of dissolved ions in the partial stream 19 to be monitored with sensors before and after the ion exchange device 24, respectively. For this purpose, sensor devices for monitoring the content of dissolved ions in the partial stream 19 can be provided in each case upstream and downstream of the ion exchange device 24 in terms of flow. Such a sensor device may be formed, for example, by a conductivity sensor or other suitable measuring device which allows conclusions to be drawn about the content of ions.

As shown by way of example in fig. 2, a pH sensor 34 can be arranged fluidically before and after the ion exchanger device 24. In this way, during operation of the pasteurization device 1, the content of dissolved ions in the at least one partial stream 19 can be monitored by measuring the pH of the at least one partial stream 19 before and after the removal of ions by means of the ion exchange device 24, respectively.

This makes it possible, for example, to detect a sudden increase in the concentration of dissolved ions in the partial flow 19 or in the treatment liquid as a whole by providing the pH sensor 34. For example, a sudden increase in the concentration of metal cations in the treatment liquid can be detected, since the metal cations are solvated with H by the at least one strongly acidic cation exchanger 32⁺And (4) ion replacement. This can in turn be detected by means of the pH sensor 34 directly by a sudden drop in the pH of the at least one partial stream 19 after it has passed through the at least one cation exchanger 32 of the ion exchange device 24. If necessary, countermeasures are then taken in order to prevent further contamination of the treatment liquid by the undesired dissolved ions. By providing the pH sensor 34, it is even possible to detect errors in the execution of the pasteurization process or unplanned and undesired effects on the process (for example due to an unsealed or metal or aluminum dust-contaminated container). Such a system of pH sensors 34 is on the other hand also suitable as a reference device or measuring device for influencing the pH value of the at least one partial stream 19 towards a desired pH value level.

The pH value of the at least one branched partial stream 19 can be influenced by means of the ion exchanger 24, for example, by adjusting the flow rate of the treatment liquid through the ion exchanger 24. For this purpose, for example, a flow rate control device 35 is assigned to the at least one purification device 16 as a control device 21 for adjusting or setting a defined volume flow of the at least one partial flow 19, as is shown in fig. 1 and also in fig. 2. The flow regulating device 35 may comprise a flow regulating means 36, such as a flow regulating valve or an adjustable flap, or other suitably adjustable regulating mechanism. Furthermore, the flow rate regulating device 35 comprises a flow rate sensor device 37 for measuring the respective flow rate of the treatment liquid through the purification device 16 or the volumetric flow of the at least one partial flow 19 through the purification device. In operation of the pasteurization device 1, the partial quantity of the treatment liquid 4 diverted from the at least one circulation circuit 11 to form the at least one partial stream 19 can therefore be set by means of the flow rate setting device 35. The pH value of the at least one partial stream 19 can thereby be influenced again, since depending on the flow rate or depending on the volume flow of the at least one partial stream 19, more or less dissolved ions are exchanged by means of the strongly acidic cation exchanger 32 and, if appropriate, by means of the strongly basic anion exchanger 33. As schematically shown in fig. 2, an additional delivery device 12, for example a pump, preferably with a rotational speed that is regulated, can also be used for regulating the flow rate of the treatment liquid through the purification device 16.

In principle, the ion exchange device 24 can be arranged in the at least one purification device 16 in such a way that the entire partial flow 19 of the treatment liquid 4 diverted or withdrawn from the at least one recirculation circuit 11 is conducted through the ion exchange device 24, as is schematically illustrated in fig. 1. However, it is also suitable for the ion exchange device 24 to be arranged in the at least one purification device 16 via at least one flow rate control device 38 in parallel fluidically with a through-flow line 39 for the partial flow 19, as is shown in connection with the exemplary embodiment according to fig. 2. In operation of the pasteurization device 1, at least a part of the treatment liquid is thus extracted from the partial stream 19 by means of at least one flow rate control structure 38, for example also the flow rate control means 36, conducted through the ion exchange device 24 and then back into the partial stream 19 again. In principle, the flow rate of the treatment liquid through the ion exchange device 24 can thereby be set independently of the other elements of the at least one purification device 16, and the amount of dissolved ions exchanged per unit time can thus be influenced in a targeted manner. In particular, the influence on the pH value of the at least one partial stream 19 can be effected independently of the other elements of the at least one purification device 16. As shown in fig. 2, an additional delivery device 12, for example a pump, preferably with a rotational speed that is set, can also be used for setting the flow rate of the treatment liquid through the ion exchange device 24.

Alternatively or additionally, however, it may also be advantageous to provide each ion exchanger 32, 33 of the ion exchange device 24 with a flow rate control device 38. In operation of the pasteurization device 1, the flow rate of the treatment liquid through the respective ion exchanger 32, 33 can thus be adjusted individually by means of a respective flow rate adjustment device 38 for the ion exchanger 32, 33 of the ion exchange device 24, as can be seen from fig. 2. In this way, the removal of dissolved ions from the at least one partial stream 19 can also be regulated or controlled more precisely and a further improved or more precise influencing of the pH value of the at least one partial stream 19 can additionally take place.

As also shown in fig. 2, the ion exchanger device 24 can be fluidically connected to at least one regeneration means 40, 41 for regenerating the ion exchangers 32, 33. Here, it is naturally possible to provide the regeneration mechanism 40 with the regeneration liquid for the cation exchanger 32 and the regeneration mechanism 41 with the regeneration liquid for the anion exchanger 33. In this case, during operation of the pasteurization device 1, the ion exchangers 32, 33 can be regenerated as required. In particular, it can be provided that the at least one strongly acidic cation exchanger 32 is regenerated as a function of the change in the pH of the partial stream 10. It can also be provided that the at least one strongly basic anion exchanger 33 is regenerated as a function of the change in the pH value of the partial stream 19. For this purpose, as already described, pH sensors 34 can be provided before and after the ion exchange device 24, respectively. The used regeneration liquid can again be conducted out through the outflow opening 31.

In order to further improve the purification efficiency for the treated liquid, the at least one purification device 16 comprises a further liquid treatment device 42 comprising a metal braid or metal particles with copper and/or zinc. The liquid treatment device 42 can be arranged fluidically between the membrane filtration device 23 and the ion exchange device 24 in the at least one purification device 16. The liquid treatment device 42 can optionally be blocked or flowed through, and a through-flow line 39, which is fluidically connected in parallel to the partial flow 19, is provided in the at least one purification device 16, as is shown in fig. 2. In operation of the pasteurization device 1, the at least one partial flow can then additionally be conducted through a liquid treatment device comprising metal particles or metal braids with copper and/or zinc before the dissolved ions are removed.

With such a liquid treatment device 42, it is possible to trigger a spontaneous oxidation and/or reduction reaction of some substances dissolved in the treatment liquid during operation of the pasteurization device 1. Thereby, noble metal cations, such as heavy metal ions, iron ions, etc., are separated from the diverted partial stream 19, for example in comparison to zinc and/or copper. This is advantageous in turn for the efficiency of the subsequent ion exchange device 24, since the ions which have already been removed by means of the liquid treatment device 42 no longer have to be removed from the at least one partial stream 19 by means of the ion exchange device 24 or do not compete in ion exchange with other dissolved ions in the partial stream 19. The available ion exchange capacity of the ion exchangers 32, 33 of the ion exchange device 24 is thus advantageously provided for extracting or removing other undesired dissolved ions, for example aluminum ions or ions of aluminum compounds, which cannot be removed by means of the liquid treatment device 42.

Furthermore, it can be provided that the at least one purification device 16 has an adsorption device 43, which adsorption device 43 is arranged fluidically downstream of the ion exchange device 24. The adsorption device 43 can have, for example, an activated carbon filter 44. In this way, in operation of the pasteurization device 1, dissolved substances can be removed from the at least one partial stream 19 additionally by means of the adsorption device 43, for example by means of the activated carbon filter 44, after removal of the dissolved ions by means of the ion exchange device 24.

It would basically be expedient for the at least one purification device 16 to be arranged on the circulation circuit 11 or to be connected in line with the circulation circuit 11, in which, in the operation of the pasteurization device 1, the treatment liquid 4 having a lower temperature is conducted, as is also shown in fig. 1. In this way, the individual devices 23, 26, 42, 43 of the at least one purification device 16 are operated in particular as protected as possible. Nevertheless, an efficient continuous purification of the treatment liquid 4 is achieved, since in the pasteurization device 1, due to the flow or forced transport of the treatment liquid through the one or more circulation circuits 11, a continuous mixing of the individual volume elements of the treatment liquid 4 is achieved. In these cases, the individual volume elements of the treatment liquid 4 are therefore guided in continuous operation over time through the switched circuit 11 or are supplied to and removed from the switched treatment zone 2. It is thereby also possible in the following to influence the pH level of the entire treatment liquid by exchanging the dissolved ions of the at least one partial stream 19 by means of the ion exchange device 24 of the at least one purification device 16.

Finally, fig. 3 shows, in part, a further exemplary embodiment of a pasteurization device 1, which can be advantageous for the continuous reuse and cleaning of the treatment liquid 4. The same reference numerals or component numerals as in the previous fig. 1 and 2 are used in fig. 3 for the same components. To avoid unnecessary repetition, reference is made to or otherwise detailed description in the foregoing fig. 1 and 2.

As can be seen from the exemplary embodiment of the pasteurization device 1 shown partially in fig. 3, it can be provided that the pasteurization device 1 comprises an air-cooled cooling tower 45 with a heat exchanger 46 through which the treatment liquid 4 can flow as required. In this way, a partial volumetric flow of the treatment liquid 4 can be guided as required through the heat exchanger 46 of the air-cooled cooling tower 45.

An air-cooled cooling tower is usually required in a pasteurization installation for cooling a portion of the treatment liquid 4, which cooled treatment liquid 4 can be used, for example, in turn for cooling containers after pasteurization. Due to the high cooling capacity of the cooling tower, which is usually required, a large amount of impurities can enter the conventional cooling tower without a heat exchanger. By providing the heat exchanger 46, impurities can be effectively prevented from entering the process liquid 4 through the air-cooled cooling tower 45 or in the air-cooled cooling tower 36.

As shown in fig. 3, it can be provided, for example, for cooling a partial quantity of the treatment liquid 4, if necessary for transferring the partial quantity of the treatment liquid 4 from the circulation circuit 11 by means of the conveying device 12 into a treatment liquid reservoir 38, for example a collecting container or the like. The treatment liquid 4 can then be pumped, if required, from the treatment liquid reservoir 47, by means of a further conveying device 12, through the heat exchanger 46 of the cooling tower 45, cooled there by cooling air, and returned again into the treatment liquid reservoir 47. The cooled treatment liquid 4 from the treatment liquid reservoir 47 can now be supplied to the circulation circuit 11 which is shown by way of example in fig. 3.

The examples show possible embodiment variants, wherein it is to be noted here that the invention is not limited to the specifically illustrated embodiments of the invention, but that different combinations of the individual embodiments with one another are also possible and that such variant possibilities are within the reach of a person skilled in the art on the basis of the teaching of the invention for technical treatment.

The scope of protection is determined by the claims. The specification and drawings may be used to interpret the claims. Individual features or combinations of features of the different embodiments shown and described may constitute independent inventive solutions. The purpose of these separate inventive solutions can be derived from the description.

In the present description, all statements made with respect to numerical ranges are to be understood such that they include any and all subranges therein at the same time, for example statements 1 to 10 are to be understood such that all subranges based on a lower limit of 1 and an upper limit of 10 are included at the same time, i.e. all subranges beginning with a lower limit of 1 or more and ending with an upper limit of 10 or less, for example 1 to 1.7, or 3.2 to 8.1, or 5.5 to 10.

For compliance with the regulations, it is finally pointed out that the elements are in part not shown to scale and/or are shown exaggerated and/or reduced in size for a better understanding of the construction.

List of reference numerals

1 pasteurization installation

2 treatment zone

3 supply mechanism

4 treating liquids

5 outer side

6 container

7 conveying device

8 conveyer belt

9 direction of conveyance

10 bottom zone

11 circulation loop

12 conveying mechanism

13 mechanism

14 mechanism

15 heating device

16 purification device

17 extraction mechanism

18 return mechanism

19 part stream

20T-shaped piece

21 control device

22 blocking mechanism

23 Membrane filtration device

24 ion exchange device

25 guide mechanism

26 Filter Module

27 retentate space

28 sealing mechanism

29 permeate space

30 source of counter-current flushing liquid

31 outflow opening

32 cation exchanger

33 anion exchanger

34 pH value sensor

35 flow regulating device

36 flow regulating device

37 flow sensor device

38 flow regulating mechanism

39 through-flow line

40 regenerative mechanism

41 regeneration mechanism

42 liquid treatment device

43 adsorption device

44 activated carbon filter

45 cooling tower

46 heat exchanger

47 reservoir for treatment liquid