PASTEURIZING DEVICE AND METHOD FOR OPERATING A PASTEURIZING DEVICE

Abstract

A method operates a pasteurizing device and a pasteurizing device pasteurizes foodstuff in sealed containers. The pasteurizing device includes a treatment area configured for temperature treatment of the foodstuff in the containers with at least one heating zone, a conveying system for conveying the sealed containers filled with foodstuff through the treatment area and an irrigation device configured for dispensing a temperature-controlled process liquid into the at least one heating zone. The pasteurizing device further includes at least one feed device configured for introducing at least one treatment chemical for container-treatment in gaseous or aerosolized state into the treatment area.

Claims

1. A method for operating a pasteurizing device comprising a first operating condition, wherein in the first operating condition sealed containers filled with foodstuff are conveyed through a treatment area comprising at least one heating zone, the foodstuff is heated and pasteurized in the at least one heating zone by dispensing a temperature-controlled process liquid onto the containers, wherein at least a major part of the process liquid from the treatment area is returned to the treatment area in a closed-loop circuit for reuse, wherein based on demand at least one treatment chemical for container-treatment is introduced into the treatment area in a gaseous or aerosolized state by means of a feed device in any operating condition of the pasteurizing device.

2. The method according to claim 1, wherein the at least one treatment chemical is introduced into the treatment area by means of a carrier gas flow.

3. The method according to claim 1, wherein the at least one treatment chemical is vaporized prior to introduction into the treatment area.

4. The method according to claim 3, wherein the at least one treatment chemical is evaporated into a carrier gas prior to introduction into the treatment area, and subsequently is introduced into the treatment area by means of the carrier gas.

5. The method according to claim 3, wherein the vaporizing is conducted or supported by means of a heating device.

6. The method according to claim 3, wherein the vaporizing is conducted or supported by means of applying a vacuum.

7. The method according to claim 1, wherein the at least one treatment chemical is nebulized into the treatment area, or wherein the at least one treatment chemical is nebulized prior to introduction into the treatment area by means of an aerosolizing device.

8. The method according to claim 1, wherein an amount of the at least one treatment chemical introduced into the treatment area is controlled by means of at least one metering device.

9. The method according to claim 1, wherein the at least one treatment chemical is introduced into the treatment area during a second operating condition, wherein in the second operating condition the conveying of the containers and the dispensing of temperature-controlled liquid onto the containers is or has stopped.

10. The method according to claim 1, wherein in the first operating condition sealed containers comprising a metal material on an exterior of the containers are conveyed through the treatment area.

11. The method according to claim 10, wherein containers comprising aluminum on the exterior are conveyed through the treatment area.

12. The method according to claim 10, wherein the at least one treatment chemical introduced into the treatment area comprises a volatile carboxylic acid.

13. The method according to claim 12, wherein the at least one treatment chemical introduced into the treatment area comprises formic acid or acetic acid.

14. The method according to claim 1, wherein at least in the first operating condition a partial quantity of the process liquid is continuously taken out of the closed-loop circuit per time unit, and is purified by means of a membrane filtration device and subsequently by means of an ion exchanger device and/or by means of an adsorption device, and the purified process liquid is returned into the treatment area.

15. Pasteurizing device for pasteurizing foodstuff in sealed containers, comprising a treatment area configured for temperature treatment of the foodstuff in the containers with at least one heating zone, a conveying system for conveying the sealed containers filled with foodstuff through the treatment area, irrigation means configured for dispensing a temperature-controlled process liquid into the at least one heating zone, a closed-loop circuit configured for returning process liquid from the treatment area back into the treatment area for reuse, wherein the pasteurizing device comprises at least one feed device configured for introducing at least one treatment chemical for container-treatment in gaseous or aerosolized state into the treatment area.

16. The pasteurizing device according to claim 15, wherein the feed device comprises a means for generating a carrier gas flow, and wherein the feed device is configured for transporting the at least one treatment chemical into the treatment area by means of the carrier gas flow.

17. The pasteurizing device according to claim 16, wherein the feed device is configured for guiding the carrier gas through an evaporating space containing the at least one treatment chemical, and subsequently into the treatment area.

18. The pasteurizing device according to claim 15, wherein the feed device comprises a heating device configured for vaporizing the at least one treatment chemical or for supporting vaporization of the treatment chemical.

19. The pasteurizing device according to claim 15, wherein the feed device comprises a vacuum device configured for vaporizing the at least one treatment chemical or for supporting vaporization of the at least one treatment chemical.

20. The pasteurizing device according to claim 15, wherein the feed device comprises at least one aerosolizing means configured for nebulizing the at least one treatment chemical into the treatment area.

21. The pasteurizing device according to claim 15, wherein the feed device comprises an aerosolizing device configured for nebulizing the at least one treatment chemical prior to introduction into the treatment area.

22. The pasteurizing device according to claim 15, wherein the feed device comprises at least one metering device configured for controlling an amount of treatment chemical introduced into the treatment area.

23. The pasteurizing device according to claim 15, wherein the feed device comprises feed orifices arranged at or in different temperature treatment zones of the treatment area.

24. The pasteurizing device according to claim 23, wherein at least one shut-off device is associated with a feed orifice, or with a group of feed orifices.

25. The pasteurizing device according to claim 15, comprising at least one removing means configured for removal of a partial quantity of the process liquid from the closed-loop circuit per time unit, and a purification device comprising a membrane filtration device and an ion exchanger device and/or an adsorption device downstream of the membrane filtration device configured for cleaning the removed partial quantity of the process liquid, and at least one returning means configured for returning the purified process liquid back into the treatment area.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Other objects and features of the invention will become apparent from the following detailed description considered in connection with the accompanying drawings. It is to be understood, however, that the drawings are designed as an illustration only and not as a definition of the limits of the invention.

[0047] In the drawings, which are higly simplified, schematic drawings:

[0048] FIG. 1 shows an exemplary embodiment of a pasteurizing device;

[0049] FIG. 2 shows an exemplary embodiment of a feed device con figured for introducing at least one treatment chemical in gaseous state into a treatment are of a pasteurizing device;

[0050] FIG. 3 shows another exemplary embodiment of a feed device configured for introducing at least one treatment chemical in gaseous state into a treatment are of a pasteurizing device;

[0051] FIG. 4 shows another exemplary embodiment of a feed device configured for introducing at least one treatment chemical in gaseous state into a treatment are of a pasteurizing device;

[0052] FIG. 5 shows another exemplary embodiment of a feed device comprising an aerosolizing means;

[0053] FIG. 6 shows another exemplary embodiment of a feed device comprising an aerosolizing means.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0054] Introductory, it should be pointed out, that the same parts described in the different embodiments are denoted by the same reference numbers and the same component names and the disclosures made throughout the description can be transposed in terms of meaning to same parts bearing the same reference numbers or same component names. Furthermore, the positions chosen for the purposes of the description, such as top, bottom, side, etc., relate to the drawing specifically being described and can be transposed in terms of meaning to a new position when another position is being described.

[0055] FIG. 1 schematically shows an exemplary embodiment of a pasteurizing device 1 for pasteurizing foodstuff in sealed containers 2. The pasteurizing device 1 is configured as so-called tunnel pasteurizer, and comprises a treatment area 3 configured for temperature treatment of the containers with at least one heating zone 4. The treatment area 3 of the pasteurizing device 1 shown in FIG. 1 as example comprises a second heating zone 5 for further heating up the foodstuff, two heating zones 6, 7 for pasteurizing the foodstuff in the containers 2, and two cooling zones 8, 9 for cooling down the foodstuff. Depending on need or purpose, it is of course possible for a pasteurizing device 1 to comprise more or fewer zones 3, 4, 5, 6, 7, 8, 9 as compared to the exemplary embodiment shown in FIG. 1. It is likewise possible for further treatment zones to be provided in the treatment area 3. For example, a zone for drying the outer side of the containers 2 could be provided after the last cooling zone 9. For reasons of clarity, such alternative designs of pasteurizing devices are not described. A person skilled in the art will appreciate, that the present invention implies such alternative designs of pasteurizing devices or treatment areas, respectively.

[0056] The example for a pasteurizing device 1 shown in FIG. 1 comprises a conveying system 10 for conveying the sealed containers 2 filled with foodstuff through the treatment area 3 in a transport direction 11. The conveying system may for example comprise a conveyor belt, which is pervious liquids and gases. The pasteurizing device 1 further comprises irrigation means 12 configured for dispensing a temperature-controlled process liquid into the temperature treatment zones 4, 5, 6, 7, 8, 9 of the treatment area 3. The irrigation means 12 may for example be sprinkler or shower devices known in the art, configured for dispensing the respective temperature-controlled process liquid onto the containers 2.

[0057] In a first or normal operation condition of the exemplary pasteurizing device 1 shown in FIG. 1, sealed containers 2 filled with foodstuff are conveyed through the treatment area 3 comprising the heating zones 4, 5, 6, 7 and the cooling zones 8, 9. In the example shown in FIG. 1 the foodstuff is heated and pasteurized in two heating zones 6, 7 by dispensing a temperature-controlled process liquid onto the containers 2. For the purpose of pasteurizing the foodstuff, a temperature of the process liquid dispensed onto the containers 2 in heating zones 6, 7 is selected high enough for pasteurization. These heating zones 6, 7 may also be referred to as pasteurizing zones 6, 7. In the exemplary embodiment of the pasteurizing device 1 shown in FIG. 1, the foodstuff in the containers 2 is heated up in a controlled manner in the heating zones 4, 5, prior to pasteurization in heating zones 6, 7. Typically a temperature of the process liquid dispensed into these pre-heating zones 4, 5 will be growing from heating zone 4 to heating zone 5. After having been temperature-treated in the heating zones 4, 5, 6, 7, the foodstuff in the containers 2, is then cooled down in a controlled manner by dispensing process liquid with a temperature low enough for cooling the containers 2 in cooling zones 8, 9.

[0058] After having crossed the respective temperature treatment zones 4, 5, 6, 7, 8, 9 the process liquid may be collected at bottom areas 13 of the treatment zones 4, 5, 6, 7, 8, 9, wherein at least a major part of the process liquid from the treatment area 3 is returned to the treatment area 3 for reuse. For this purpose, the pasteurizing device 1 comprises a closed-loop circuit 14 configured for returning process liquid from the treatment area 3 back into the treatment area 3 for reuse. For reusing the process liquid, the pasteurizing device 1 may comprise recuperation lines 54, arranged for transporting process liquid collected in the bottom areas 13 of temperature treatment zones 4, 5, 8, 9 directly back into different temperature treatment zones 4, 5, 8, 9, as can be depicted from the example for a pasteurizing device 1 shown in FIG. 1. In the first operating condition, at least a portion of the process liquid from the bottom area 13 of the last cooling zone 9 may for example be transferred to the first heating zone 4, and vice versa. Such recuperation of process liquid is particularly meaningful with the pasteurizing device 1 shown as example in FIG. 1, as the temperature of the process liquid falls upon heating up the containers 2 in the heating zones 4, 5, and rises upon cooling down the containers 2 in the cooling zones 8, 9. Circulation devices 15, for example circulation pumps may be used to convey the process liquid in the closed-loop circuit 14, as is shown in FIG. 1.

[0059] Portions of process liquid with comparatively high temperature level collected at the bottom areas 13, may be transferred to a hot collection tank 16 of the pasteurizing device 1 for example. Portions of process liquid with comparatively low temperature level collected at the bottom areas 13, may be transferred to a cold collection tank 17. The process liquids in the hot and cold collection tanks 16, 17 may be used to set or adjust respective temperatures for process liquid to be fed into the individual temperature treatment zones 4, 5, 6, 7, 8, 9. For this purpose, each of the circulation devices 15 on an input side may be connected with the hot and cold collection tanks 16, 17 via metering valves 18, as shown in the embodiment according to FIG. 1. In this way, process liquid from the hot collection tank 16 and the cold collection tank 17 may be used in the closed-loop circuit 14 for temperature-adjustment of process liquid flows to be fed into one of the individual, respective temperature treatment zones 4, 5, 6, 7, 8, 9 of the pasteurizing device 1, by adding certain amounts of process liquid from the hot and cold collection tanks 16, 17 in a controlled manner.

[0060] For heating up the process liquid in the pasteurizing device 1, a heating means 19 may be provided, for cooling the process liquid a cooling means 20 may be provided. The heating means 19 and the cooling means 20 may both for example be heat exchangers, wherein a primary side of the heat exchangers 19, 20 may be connected with a heating device (not shown) and a cooling device (not shown) respectively. A water steam generator may be used as heating device for example, an air- or water-cooled cooling tower may be used as cooling device. Alternatively or in addition, it may be expedient to use a heat pump as heating and cooling device.

[0061] As is shown in FIG. 1, the pasteurizing device 1 comprises at least one feed device 21 configured for introducing at least one treatment chemical for container-treatment in gaseous or aerosolized state into the treatment area 3. By means of the feed device 21, at least one treatment chemical for container-treatment can be introduced into the treatment area 3 in a gaseous or aerosolized state. The introduction of the treatment chemical into the treatment area 3 can be conducted based on demand and in any operating condition of the pasteurizing device 1, as the introduction is independent from whether process liquid is dispensed into the treatment area 3, respectively the temperature-treatment zones 4, 5, 6, 7, 8, 9, or not.

[0062] The feed device 21 may for example comprise reservoirs 22 containing treatment chemicals. A treatment chemical may be a gas under standard temperature and pressure (STP) conditions. In such case, a gaseous treatment chemical may be introduced into the treatment area 3 directly from the corresponding reservoir 22, for example in pure form or diluted in a carrier gas. In many cases, suitable treatment chemicals are not gaseous under STP conditions however, so that the feed device 21 may comprise means for vaporizing or aerosolizing such treatment chemicals. Some embodiments of the feed device 21 comprising such means for vaporizing or aerosolizing treatment chemicals will be described in the following with reference to the figures.

[0063] Irrespective therefrom, the feed device 21 may comprise feed orifices 23 arranged at or in different temperature treatment zones 4, 5, 6, 7, 8, 9 of the treatment area 3, and feed lines 24 for supplying the at least one treatment chemical to the feed orifices 23 for introduction of the at least one treatment chemical into the treatment area 3, respectively the temperature-treatment zones 4, 5, 6, 7, 8, 9. Furthermore, at least one shut-off device 25 may be associated with a feed orifice 23, or with a group of feed orifices 23, such that the at least one treatment chemical may be introduced into only specific temperature-treatment zones 4, 5, 6, 7, 8, 9 of the pasteurizing device 1 for example. A shut-off device 25 as shown in FIG. 1 may for example be an open/close valve, or a metering valve.

[0064] In the example shown in FIG. 1, feed orifices 23 are arranged in or at all of the temperature treatment zones 4, 5, 6, 7, 8, 9, such that the whole treatment area 3 can be supplied with treatment chemical(s). In alternative embodiments, feed orifices 23 may be arranged in or at specific temperature treatment zones 4, 5, 6, 7, 8, 9 only. The feed orifices 23 may for example be arranged in the treatment area 3 underneath the pervious conveyor belt 10 for introducing the gaseous or aerosolized treatment chemical to an area below the containers 2. Other arrangements of the feed orifices 23 are also possible, for example an arrangement which allows for applying the at least one treatment chemical from multiple sides onto the containers 2.

[0065] FIG. 2 shows a schematic view of an embodiment of a feed device 21 for introducing at least one treatment chemical in gaseous state into the treatment area 3, in more detail. The same reference numbers and component names are used in FIG. 2 to denote parts that are the same as those described above in connection with FIG. 1. To avoid unnecessary repetition, reference may be made to the more detailed description of FIG. 1 given above. As can be depicted from FIG. 2, the feed device 21 may comprise a means 26 for generating a carrier gas flow. In the exemplary embodiment shown in FIG. 2 the feed device 21 is configured for transporting the at least one treatment chemical into the treatment area 3 by means of the carrier gas flow.

[0066] The means 26 for generating the carrier gas flow, may for example be a pressure vessel 27 filled with the carrier gas, and equipped with a throttle valve 28. The carrier gas within the pressure vessel may be air or an inert gas like nitrogen or argon for example. Alternatively, a small-sized, driven fan 29 or any other airflow generating means may be used the generate the carrier gas flow, as indicated with dashed lines in FIG. 2. With the features of the exemplary embodiment of the feed device 21 shown in FIG. 2, the at least one treatment chemical can be introduced into the treatment area 3 by means of the carrier gas flow.

[0067] In case the at least one treatment chemical is not gaseous under STP conditions, the at least one treatment chemical may be vaporized prior to introduction into the treatment area 3. For example, the at least one treatment chemical may be evaporated into the carrier gas prior to introduction into the treatment area 3, and subsequently may be introduced into the treatment area 3 by means of the carrier gas. The embodiment of the feed device 21 shown in FIG. 2 is configured for guiding the carrier gas through an evaporating space 30 containing the at least one treatment chemical, and subsequently into the treatment area 3.

[0068] For this purpose, the at least one treatment chemical may for example be pumped from a reservoir 22 into an evaporating space 30 of an evaporator 31 by means of a liquid pump 32. The feed device 21 may be configured to guide the carrier gas through the liquid treatment chemical, such that the evaporator 31 is configured as throughflow evaporator in this case. Alternatively the feed device 21 may be configured to guide the carrier gas through a gas space over the liquid treatment chemical, such that the evaporator 31 is configured as surface evaporator. As is shown in FIG. 2, the feed device 21 may comprise a heating device 33 for supporting the evaporation of the at least one chemical into the carrier gas.

[0069] In an alternative embodiment shown in dashed lines in FIG. 2, the feed device 21 may be configured for guiding the carrier gas directly through an evaporating space 30 of the reservoir 22 containing the treatment chemical. In such case the reservoir 21 is configured as evaporator 31 itself. Either way, the carrier gas may be guided through an evaporating space 30, wherein the at least one treatment chemical is evaporated into the carrier gas, and the carrier gas saturated with the treatment chemical is then introduced into the treatment area 3 via the feed line 24 and feed orifices 23.

[0070] With the exemplary embodiment of the feed device 21 shown in FIG. 2, the amount of treatment chemical introduced into the treatment area 3 can in principle be controlled manually or automatically by engaging liquid pump 32 and/or engaging the carrier gas flow for a certain time period. Preferably, the amount or quantity of treatment chemical introduced into the treatment area 3 is controlled automatically by at least one metering device 34. The feed device 21 shown as example in FIG. 2 comprises at least one metering device 34 configured for controlling the amount of treatment chemical introduced into the treatment area 3.

[0071] In the exemplary embodiment shown in FIG. 2, the at least one metering device 34 may be a mass or volumetric gas flow controller 35 for example. In this case, the concentration of treatment chemical in the carrier gas flow after having passed through the evaporating space 30 can in principle be measured by suitable measuring devices, or can be calculated in advance by using the known temperature and the known throughput rate of the carrier gas through the evaporator 31. By means of such gas flow controller 35, the amount or quantity of treatment chemical introduced into the treatment area 3 can then be controlled by means of the amount of carrier gas introduced into the treatment area 3.

[0072] FIG. 3 shows another example of a feed device 21 configured for introducing at least one treatment chemical for container-treatment in gaseous state into the treatment area 3. The same reference numbers and component names are used in FIG. 3 to denote parts that are the same as those described above in connection with FIG. 1 and FIG. 2. To avoid unnecessary repetition, reference may be made to the more detailed description of FIG. 1 and FIG. 2 given above.

[0073] The example shown in FIG. 3 also comprises a reservoir 22 and a means 26 for generating a carrier gas flow. The exemplary feed device 21 shown in FIG. 3 comprises a vaporizer 36 for vaporizing the at least one treatment chemical. In case of the example shown in FIG. 3, a limited amount or quantity of liquid treatment chemical may be fed into the vaporizer 36 from the reservoir 22 by means of a metering device 34. The metering device 34 may be a liquid metering pump 37, like a small piston metering pump, or a peristaltic pump for example. The liquid treatment chemical may then for example vaporized in the vaporizer 36 by means of a heating device 33 prior to introduction into the treatment area 3 by means of the carrier gas flow, or the heating means 33 may be used to support evaporation of the treatment chemical into the carrier gas flow within the vaporizer 36.

[0074] As shown in FIG. 3, the feed device 21 may comprise a vacuum device 38 configured for vaporizing the at least one treatment chemical or for supporting vaporization of the at least one treatment chemical. The vaporizing of the at least one treatment chemical may be conducted or supported by means of applying a vacuum in this way. The feed device 21 may comprise shut-off devices 25, for allowing or prohibiting the carrier gas from flowing through the vaporizer 36. As can be depicted from FIG. 3, the vaporizer 36 can be shut off from the means 26 for generating the carrier gas flow, as well as from the treatment area 3. In closed position of the shut-off means 25, a certain amount of liquid treatment chemical can be introduced into the vaporizer 36 from the reservoir 21. The liquid treatment chemical may then be vaporized in the vaporizer 36 by means of the vacuum device 38, or by means of the heating device 33, or by means of both the vacuum device 38 and the heating device 33.

[0075] After vaporizing the treatment chemical, the shut-off devices 25 can then be opened, to allow carrier gas to flow through the vaporizer 36, and carry the vaporized treatment chemical into the treatment area 3. The shut-off devices 25 may also be configured as gas flow controllers 35, in order to provide a means for controlling the amount of carrier gas and treatment chemical introduced into the treatment area 3 per time unit.

[0076] In FIG. 4, another example of a feed device 21 configured for introducing at least one treatment chemical for container-treatment in gaseous state into the treatment area 3 is shown. The same reference numbers and component names are used in FIG. 4 to denote parts that are the same as those described above in connection with FIG. 1 to FIG. 3. To avoid unnecessary repetition, reference may be made to the more detailed description of FIG. 1 to FIG. 3 given above.

[0077] FIG. 4 shows an embodiment, which is especially suited for introducing relatively high amounts of treatment chemical in gaseous state into the treatment area 3, per time unit. The feed device 21 comprises a reservoir 22 for a liquid treatment chemical and vaporizer 36 with a heating device 33 for vaporizing the liquid treatment chemical. In case of the example shown in FIG. 4, no carrier gas flow is used to introduce the treatment chemical into the treatment area 3. The treatment chemical is directly vaporized in the vaporizers 36, and enters the treatment area 3 in gaseous state due to the higher pressure generated in the vaporizer 36.

[0078] FIG. 5 shows an example of a feed device 21 configured for introducing the at least one treatment chemical for container-treatment in aerosolized state into the treatment area 3. The same reference numbers and component names are used in FIG. 5 to denote parts that are the same as those described above in connection with FIG. 1 to FIG. 4. To avoid unnecessary repetition, reference may be made to the more detailed description of FIG. 1 to FIG. 4 given above.

[0079] As shown in FIG. 5, the feed device 21 may comprise at least one aerosolizing means 39 configured for nebulizing the at least one treatment chemical into the treatment area 3. The aerosolizing means 39, may comprise atomizing or spraying nozzles 40. A controlled amount of treatment chemical may for example be pumped from a reservoir 22 into a buffer storage 41, by means of a metering device 34, for example a liquid metering pump 37. The treatment chemical may then for example be fed through the atomizing or spraying nozzles 40 by means of a high pressure pump 42, and be nebulized into the treatment area 3. Alternatively or in addition, the spraying nozzles 40 may be connected with a source of pressurized gas or air, like the compressor 43 shown in FIG. 5. The aerosolizing may then be accomplished or supported by the pressurized gas or air. With the design of the feed device 21 shown in FIG. 5, the at least one treatment chemical may be nebulized into the treatment area 3.

[0080] As also shown in FIG. 5, the feed device 21 may also comprise a reservoir 44 for an auxiliary substance for supporting nebulizing of the treatment chemical. In this case, the buffer storage 41 may be configured as mixing unit 45 for mixing the treatment chemical with the auxiliary substance, and then nebulizing the mixture into the treatment area 3 by means of the atomizing or spraying nozzles 40. The auxiliary substance may for example be water.

[0081] FIG. 6 shows another example of a feed device 21 configured for introducing the at least one treatment chemical for container-treatment in aerosolized state into the treatment area 3. The same reference numbers and component names are used in FIG. 6 to denote parts that are the same as those described above in connection with FIG. 1 to FIG. 5. To avoid unnecessary repetition, reference may be made to the more detailed description of FIG. 1 to FIG. 5 given above.

[0082] As shown in FIG. 6, the feed device 21 may comprise an aerosolizing device 46 configured for nebulizing the at least one treatment chemical prior to introduction into the treatment area 3. Liquid treatment chemical from the reservoir 22 may be pumped into the aerosolizing device 46 by means of a metering device 34, for example the liquid metering pump 37 shown in FIG. 6. The treatment chemical may then be aerosolized in the aerosolizing device 46, and be introduced in the aerosolized state into the treatment area 3, for example by means of a carrier gas flow generated by the carrier gas flow generating means 26. An aerosolizing device 46 may for example be of vibrational or rotational type, or an ultrasonic atomizer. With the design of the feed device 21 shown in FIG. 6, the at least one treatment chemical may be nebulized prior to introduction into the treatment area 3 by means of the aerosolizing device 46.

[0083] Independent of the structural and technical design of the feed device 21, the at least one treatment chemical may be introduced into the treatment area 3 during a second operating condition. The second operating condition may be a condition, in which the conveying of the containers 2 and the dispensing of temperature-controlled liquid onto the containers 2 is or has stopped. In such second operation condition, the containers 2, the containers may have a long residence time in the treatment area 3, which may cause unwanted changes to the containers 2. This may be due to the long time of exposure of the containers 2 to vapors and condensate of the process liquid.

[0084] In a reservoir 22, the at least one treatment chemical may be provided dissolved in a solvent, or in pure form. In principle, a treatment chemical may be provided in dilute or concentrated solutions in a reservoir 22. Based on the type of treatment chemical, different solvents may be used. The solvent may be water for example, such that an aqueous solution of the treatment chemical may be provided in a reservoir 22. If the treatment chemical is provided dissolved in a solvent, at least part of the solvent may also be introduced into the treatment area 3 in gaseous or aerosolized state. Preferably, the at least one treatment chemical is provided in pure form, or in concentrated solution in a reservoir 22.

[0085] In the first operating condition sealed containers 2 comprising a metal material on an exterior of the containers 2 may be conveyed through the treatment area 3 for example. In particular, containers 2 comprising aluminum on the exterior may be conveyed through the treatment area 3. In such cases, discoloration or stain on the outside of the containers 2 is likely to occur, when the conveying of such containers 2 through the treatment area 3 is or has stopped in the second operating condition. The conveying of the containers 2 may for example have stopped due to a failure of the conveying system 10.

[0086] In order to impede such discoloration of metal surfaces, it may be expedient, that the at least one treatment chemical introduced into the treatment area 3 comprises a volatile carboxylic acid. Such volatile organic acid may be introduced into the treatment area 3 in a gaseous or aerosolized state by means of a feed device 21 according to the embodiments shown in FIG. 2 to FIG. 6, and described above. For impeding discoloration of metal surfaces, the at least one treatment chemical introduced into the treatment area 3 may comprise formic acid or acetic acid, as these treatment chemicals have proven to be effective for this purpose.

[0087] In FIG. 1, another embodiment of the invention is shown. As can be depicted from FIG. 1, the pasteurizing device 1 may comprise at least one removing means 47 configured for removal of a partial quantity of the process liquid from the closed-loop circuit 14 per time unit. Such removing means 47 may for example comprise a T-connection and a liquid flow control valve 48, as can be depicted from FIG. 1. As is further shown in FIG. 1, the pasteurizing device 1 may comprise a purification device 49 comprising a membrane filtration device 50 and an ion exchanger device 51 and/or an adsorption device 52 downstream of the membrane filtration device 50, configured for cleaning the removed partial quantity of the process liquid. The pasteurizing device 1 may further comprise at least one returning means 53 configured for returning the purified process liquid back into the treatment area 3, which returning means 53 may for example be a simple returning line leading into one of the temperature treatment zones 4, 5, 6, 7, 8, 9 of the treatment area 3.

[0088] With such design of the pasteurizing device 1, at least in the first operating condition a partial quantity of the process liquid may be continuously taken out of the closed-loop circuit 14 per time unit, and can be purified by means of the membrane filtration device 50 and subsequently by means of an ion exchanger device 51 and/or by means of an adsorption device 52, and then the purified process liquid can be returned into the treatment area 3. Preferably the purified process liquid is returned into a temperature treatment zone 4, 5, 6, 7, 8, 9, in which the temperature of the process liquid at least roughly matches the temperature of the purified process liquid.

[0089] In this way, the amount of particles, microorganisms and soluble chemicals in the process liquid can be kept low, thereby protecting the containers 2 as well as components of the pasteurizing device 1. As the method includes introducing treatment chemicals into the treatment area 3 in a gaseous or aerosolized state by means of the feed device 21, the removal of soluble chemicals does not interfere with the addition of the treatment chemicals. The removed soluble chemicals may include treatment chemicals dissolved into the process liquid after container-treatment, which dissolving may occur especially in temperature treatment zones 4, 5, 6, 7, 8, 9 with relatively low temperature of the process liquid. Advantageously, the removing of particles prior to the removal of soluble chemicals protects the ion exchanger device 51 and/or the adsorption device 52 from getting polluted with particles.

[0090] The embodiments illustrated as examples represent possible variants and it should be pointed out at this stage that the invention is not specifically limited to the variants specifically illustrated, and instead the individual variants may be used in different combinations with one another and these possible variations lie within the reach of the person skilled in this technical field given the disclosed technical teaching.

[0091] The protective scope is defined by the claims. However, reference may be made to the description and drawings with a view to interpreting the claims. Individual features or combinations of features from the different examples of embodiments described and illustrated may also be construed as independent embodiments of the solutions proposed by the invention. The objective underlying the individual solutions proposed by the invention may be found in the description.

[0092] For the sake of good order, finally, it should be pointed out that, in order to provide a clearer understanding of the structure, elements are illustrated to a certain extent out of scale and/or on an enlarged scale and/or on a reduced scale.

LIST OF REFERENCE NUMBERS

[0093] 1 Pasteurizing device [0094] 2 Container [0095] 3 Treatment area [0096] 4 Heating zone [0097] 5 Heating zone [0098] 6 Pasteurizing zone [0099] 7 Pasteurizing zone [0100] 8 Cooling zone [0101] 9 Cooling zone [0102] 10 Conveying system [0103] 11 Transport direction [0104] 12 Irrigation means [0105] 13 Bottom area [0106] 14 Closed-loop circuit [0107] 15 Circulation device [0108] 16 Hot collection tank [0109] 17 Cold collection tank [0110] 18 Metering valve [0111] 19 Heating means [0112] 20 Cooling means [0113] 21 Feed device [0114] 22 Reservoir [0115] 23 Feed orifice [0116] 24 Feed line [0117] 25 Shut-off device [0118] 26 Means [0119] 27 Pressure vessel [0120] 28 Throttle valve [0121] 29 Fan [0122] 30 Evaporating space [0123] 31 Evaporator [0124] 32 Liquid pump [0125] 33 Heating device [0126] 34 Metering device [0127] 35 Gas flow controller [0128] 36 Vaporizer [0129] 37 Liquid metering pump [0130] 38 Vacuum device [0131] 39 Aerosolizing means [0132] 40 Nozzle [0133] 41 Buffer storage [0134] 42 High pressure pump [0135] 43 Compressor [0136] 44 Reservoir [0137] 45 Mixing unit [0138] 46 Aerosolizing device [0139] 47 Removing means [0140] 48 Flow control valve [0141] 49 Purification device [0142] 50 Membrane filtration device [0143] 51 Ion exchanger device [0144] 52 Adsorption device [0145] 53 Returning means [0146] 54 Recuperation line