SE541975C2 - Apparatus and method for producing oxygen-sensitive beverages - Google Patents

Abstract

Apparatus and method for producing oxygen -sensitive beveragesThe present invention provides an apparatus for producing oxygen-sensitive products, comprising a deaerator (100) with an inlet (2) for a product to be deaerated and a device (140) arranged downstream of the deaerator for thermal treatment of the at least partially deaerated product with a heater (142), a heat holder (144) and a cooler (146), where the deaerator (100) has a stripping gas feed line (5) for directly introducing stripping gas into an interior of the deaerator.

Description

Apparatus and method for producing oxygen-sensitive beverages Field of the invention The present invention relates to an apparatus and a method for producing oxygen-sensitive products, in particular fruit juices and carbonated soft drinks (CSD).

Background of the invention The beverage-processing industry and the food industry produce a plurality of oxygen-sensitive products, in particular liquid or semi-liquid beverages and suspensions. Examples of oxygensensitive liquids are fruit juices, fruit beverages and milk. Nowadays, a plurality of fruit juices is also offered with pieces of fruit, so-called slurries or smoothies. Other oxygen-sensitive products are flavored water, compotes and jam.

All these products have in common that the oxygen naturally contained therein has a negative effect on the product quality during the production of the product and afterwards. For example, the oxygen oxidizes the product and thereby destroys the vitamin C contained in fruit juices. Furthermore, the residual oxygen in the product shortens the minimum shelf life period of the product. Due to the oxidation, the oxygen content also influences the product quality during thermal treatment of the product. In addition, it affects the filling performance of a downstream filler due to the release of gas bubbles.

Oxygen-sensitive products are presently and hereinafter understood to be also carbonated beverages, such as beer, fruit spritzers, sodas, etc. In such carbonated beverages, the ability of the dissolved carbon dioxide to remain stable in solution is highly dependent on the oxygen content of the beverage. In particular, the residual oxygen acts as a "germ", due to its solubility that is lower than carbon dioxide, which provokes forced deaeration of the carbon dioxide, which impairs the filling process.

In order to lower the residual oxygen content in oxygen-sensitive products, the products are typically subjected to a so-called vacuum deaeration at a temperature of about 60° C prior to the filling process. Due to their high foaming potential, however, many products can not be deaerated at low vacuum pressures which would be required for filling them without problems.

The present invention is therefore based on the object of providing an apparatus and a method producing oxygen-sensitive products which in an effectively and energy-saving manner reduce the residual oxygen content of the products produced. Furthermore, the present invention is based on the object of providing an apparatus and a method for efficient carbonation of beverages.

Description of the invention The above-mentioned objects are satisfied by an apparatus for producing oxygen-sensitive products comprising a deaerator with an inlet for a product to be deaerated and a device arranged downstream of the deaerator for thermal treatment of the at least partially deaerated product with a heater, a heat holder and a cooler, where the deaerator has a stripping gas feed line for direct introduction of stripping gas into an interior of the deaerator.

According to the invention, the oxygen-sensitive products are at least partially freed from the gases contained in the products in a deaerator, in particular oxygen, and are only subsequently subjected to thermal treatment. Deaerating in the deaerator can be adapted, for example, by setting the partial pressures described farther below, by the quantity of stripping gas used and/or by the residence time of the product to be deaerated in the deaerator so as to reduce the residual oxygen and/or other residual gases below a predetermined concentration.

For this purpose, the deaerator comprises an inlet for the product to be deaerated, through which the product can be introduced into a container, for example a tank or a column, of the deaerator. The product can either be introduced continuously into the deaerator or the container can be filled with a predetermined quantity of product within the meaning of batch processing, which is subsequently deaerated. However, unlike known in prior art, deaeration does not take place solely by reducing the pressure in the deaerator to a vacuum pressure but by introducing stripping gas via a stripping gas feed line of the deaerator into an interior of the deaerator. The stripping gas is also not or not only added to the product to be deaerated prior to the introduction of the product into the deaerator. Instead, the stripping gas is introduced directly into the interior of the deaerator. In other words, the stripping gas feed line leads into the interior of the deaerator. For this purpose, the deaerator, and in particular an interior of the container or of the column, can be configured in such a manner that a well-defined atmosphere can be established in the container or the column, i.e. in particular an atmosphere with a well-defined pressure and/or composition. Since the stripping gas is introduced directly into the interior of the deaerator, the quantity of stripping gas required can be reduced in comparison with the common design in which the stripping gas is dissolved in the product to be deaerated upstream of the deaerator.

The stripping gas can be, in particular, pure hydrogen or a gas containing hydrogen, carbon dioxide or a gas containing carbon dioxide, inert gas, for example nitrogen, or other suitable gas, as well as a combination of the abovementioned gases, as shall be described farther below. Preferably, the stripping gas is sterile and free of water vapor.

According to the Henry Dalton law, the quantity of gas dissolved in a liquid depends upon the partial pressure of the gas component as well as a specific absorption coefficient which depends on the nature of the liquid and the temperature. As a consequence, the composition of a gas mixture in the liquid is different from that in the gas space that is in contact with the liquid. This means that a different partial pressure can be associated with the gas components dissolved in the liquid than with the free gas components. The partial pressure of the gases dissolved in the liquid is respectively proportional to the partial pressure of the gases present in the gas space above the liquid. By introducing the stripping gas into the gas space in the interior of the deaerator above the product to be deaerated, the partial pressure of the oxygen in the gas space that is formed by oxygen gassing out can be reduced while the total pressure of the atmosphere in the gas space is constant. Accordingly, the partial pressure of the oxygen remaining in the at least partially deaerated product can also be reduced by way of the stripping gas. In particular an devices, for example a pump, can be provided for this purpose, by use of which the total pressure of the atmosphere in the gas space can be maintained at a constant pressure, in particular below the ambient pressure. A corresponding pressure sensor, as well as a control unit, can be provided as part of the apparatus according to the invention.

The stripping gas introduced into the deaerator therefore displaces the oxygen both in the atmosphere above the product to be deaerated and also in the product to be deaerated. The stripping gas can there be respectively selected such that the abovementioned drawbacks of oxygen can be avoided, in particular, the deterioration of the product quality. When carbon dioxide or a gas containing carbon dioxide is used as the stripping gas, then the displacement of the oxygen in the deaerator also serves to carbonate the final product. Furthermore, a stripping gas having a higher solubility than oxygen can be selected, which impairs the subsequent filling process less.

According to the invention, a device for thermal treatment of the at least partially deaerated product is disposed in terms of processing downstream of the deaerator, and comprises a heater, a heat holder and a cooler. The device for thermal treatment can there in particular be configured to pasteurize the at least partially deaerated product. For example, the heater can be configured to heat the at least partially deaerated product to a temperature above 60° C, preferably to a temperature above 70° C. For this purpose, the heater can be designed having a heat ing device, for example, in the form of a heat exchanger or an electric heating device. The heat holder can be configured to maintain the heated produced at a predetermined constant temperature for a predetermined period of time, for example for pasteurization. For example, the heat holder can be configured to maintain the heated produced at the abovementioned temperature for 10, 20, 60 or 90 seconds, but preferably at least for 30 seconds For this purpose, the heat holder can be configured with correspondingly insulated lines and/or a correspondingly insulated tank, which allows the respective product quantities to be received.

Finally, the cooler can be configured to cool the heated product to a temperature suitable for storage and/or filling, for example below 25° C, preferably below 20° C. The cooler can be correspondingly connected to a heat exchanger and a suitable cooling circuit.

Since the solubility of oxygen decreases as the temperature increases, and the exchange of substances increases as the product viscosity decreases with increasing temperature, the deaerator can be integrated into the process of pasteurization. Accordingly, a device for preheating the product to be deaerated can also be provided upstream of the deaerator. By use of the device for preheating, the product to be deaerated can be heated to a predetermined temperature prior to entering the deaerator, for example between 40° C and 70° C. In the production of CSD beverages, however, the preheater can be dispensed with, firstly, for the reason that the viscosity is already quite low from the very beginning, pasteurization is not necessary due to the product properties and their microbiologically stabilizing effect, and in order to obtain improved precarbonation of the beverage in the deaerator due to the better solubility of C02at lower temperatures.

According to one development, the apparatus according to the invention can also comprise a source of pure hydrogen or a gas containing hydrogen for use as stripping gas and/or a source of carbon dioxide or a gas containing carbon dioxide for use as stripping gas. In particular, a source of a gas containing carbon dioxide can be provided which, in addition to the carbon dioxide, can also contain hydrogen and/or an inert gas, e.g. nitrogen. The respective source can in particular be a storage container, for example, a tank, for the respective gas. The source can be connected to the stripping gas feed line via respective lines and to a control valve for adjusting the desired flow of stripping gas. The quantity of stripping gas introduced into the deaerator per unit of time can be controlled by way of a control unit, in particular in dependence of the quantity of product to be deaerated that is introduced into the deaerator per unit of time. The ratio of the quantity of stripping gas [m<3>/h] relative to the product flow [m<3>/h] introduced into the deaerator can be between 0.01:1 and 1:1, preferably between 0.05:1 and 0.5:1, particularly preferably between 0.08:1 and 0.15:1.

When using pure hydrogen or a gas containing hydrogen as stripping gas, the residual content of oxygen present after deaeration is further reduced by reduction to water. The reduction effect of the hydrogen occurs, in particular, during thermal treatment of the at least partially deaerated product For example, a mixture of nitrogen and hydrogen can be used as a gas containing hydrogen in which the proportion of hydrogen is between 1% and 100%, in particular between 50% and 100%.

When using a source of carbon dioxide or a gas containing carbon dioxide as a stripping gas, in particular pre-carbonation of CSD beverages can be achieved by use of the deaerator described. For example, about 1 m<3>of carbon dioxide can be introduced into the deaerator per 10 m<3>of product. The pressure in the deaerator can be, for example, between 0.1 and 1 bar absolute, in particular between 0.2 and 0.6 bar absolute. Under these conditions, pre-carbonation is obtained based on the target content of from 0.3 to 30%, preferably from 1 to 10%, particularly preferably from 2 to 4%. According to the present invention, simultaneous and particularly efficient aerating and deaerating of the product is possible therewith. As a source of carbon dioxide or the gas containing carbon dioxide, the atmosphere above the product to be carbonated in a tank of the carbonation device can also be used, from which the gas charged with carbon dioxide is pumped off by use of a pump, in particular a controllable pump. In particular, the pressure difference between the carbonation device and the deaerator can be utilized in order to introduce the carbon dioxide or a gas containing carbon dioxide into the deaerator without any additional pump. Precise control of the quantity of stripping gas can then be effected, for example, by use of a check valve.

A device for withdrawing oxygen from a gas atmosphere can also serve as a source of pure hydrogen or a gas containing hydrogen and/or for carbon dioxide or a gas containing carbon dioxide. This can be effected, for example, by way of molecular sieves, by distillation according to the Linde method, or by catalytic combustion with hydrogen, for example on platinum-coated alumina beads. As a result, the stripping gas contaminated with the deaerated oxygen is again purified and can again be fed into the deaerator. If required, lacking stripping gas can be replenished from a storage tank.

According to one special development, the apparatus can further comprise a carbonator for the final deaerated product downstream of the device for thermal treatment of the at least partially deaerated product, where the carbonator is connected to the source of carbon dioxide or a gas containing carbon dioxide via a supply line. The carbonator is there designed to carbonate the product with the deaeration completed by adding carbon dioxide or the gas containing carbon dioxide. For example, the carbonator can be designed as a container, for example as a tank, into which the product with the deaeration completed is introduced via a feed line, where the carbon dioxide or the gas containing carbon dioxide is fed via a further feed line into a gas space above the product or directly into the product, for example, by way of a bubble-generating device. Alternatively, the carbonator can also be designed in the form of a mixing valve, by use of which the carbon dioxide or the gas containing carbon dioxide can be introduced into the product with the deaeration completed. The term "product with the deaeration completed" shall presently and hereinafter denote the product after having passed through the device for thermal treatment, i.e. after a possible reduction process has also substantially been terminated. In contrast, the term "at least partially deaerated product" shall denote the product prior to passing through the device for thermal treatment, i.e. prior to a possible reduction process. The residual oxygen content in the "product with the deaeration completed" has therefore reached its minimum, generally differing from zero.

According to this embodiment, the same source of carbon dioxide or a gas containing carbon dioxide therefore serves both as a source for the stripping gas and as a source for the carbon dioxide required for carbonation. In particular, a portion of the carbon dioxide or a gas containing carbon dioxide used for carbonation in the carbonator can be branched off as stripping gas for use in the deaerator. For this purpose, a three-way valve can be provided in the line from the source and can be regulated, in particular, by way of the control unit. In this case, the carbon dioxide or the gas containing carbon dioxide is then delivered at least in sections through a feed line common to the deaerator and the carbonator. In this manner, an extremely compact and efficient system for deaerating and carbonating beverages can be formed.

According to one development, the stripping gas feed line can be arranged in a base region of the deaerator, in which the product collects up to a filling level, such that an opening of the stripping gas feed line is disposed below the filling level. The filling level can be defined, for example, by way of the position of a discharge line for the at least partially deaerated product or an inflow and outflow control device. The container of the deaerator can comprise a base, the diameter of which decreases downwardly and is preferably formed conically and/or comprises a sensor for filling level control. According to this development, the one or more openings of the stripping gas feed line are arranged such that they are disposed below the filling level, so that the stripping gas introduced into the deaerator is introduced directly into the product and rises in the product in the form of bubbles. This ensures particularly favorable intermixing of the stripping gas and the product, which accelerates the dissolving process of the stripping gas in the product. As mentioned above, a device for the formation of bubble can also be provided at the end of the stripping gas feed line.

According to one alternative embodiment, the stripping gas feed line can open into the deaerator such that the stripping gas enters the deaerator above a filling level of product collecting in a base region of the deaerator, in particular, through a downwardly facing opening of the stripping gas feed line. According to this development, the stripping gas entering the deaerator then directly impacts the surface level of the product to be deaerated. With a suitable configuration of the deaerator, for example, in the form of the trickling film deaerator described below, the stripping gas initially strikes the surface of the product which collects at the base of the deaerator, and then rises in countercurrent to the product which is trickling down. A particularly high flow over the surface of the product to be deaerated is obtained in this manner.

As mentioned, the deaerator can be designed as a film deaerator, in particular as a trickling film deaerator. For this purpose, the deaerator can comprise a distributor device for producing a trickling film, where the inlet for the product to be deaerated is arranged in the upper region of the deaerator.

Various distributor devices can be provided for producing the trickling film. It is possible to provide, for example, a swirl inlet nozzle at the inlet for the product to be deaerated which rotates the product such that the product flows from an upper region of the container of the deaerator as a trickling film down the inner wall of the container. However, it is also possible to provide a guide screen, in particular a double screen, which injects a thin film of product in the direction of the container inner wall so that a trickling film runs down along the container inner wall. Finally, it is also possible to provide a ring line in the upper region of the container which has either several openings disposed on the circumference or an annular gap which guide the product to the inner wall of the container in such a way that the product can run as a falling film or trickling film down the inner wall of the container. It is likewise possible to fill the deaerator chamber with a packing material and to distribute the product evenly over the cross-section of the packing material by way of suitable fluid distributors. In comparison to the trickling film on the inner wall of the container, this creates a particularly high surface for gas exchange.

Such a deaerator creates a particularly large surface area of the product to be deaerated so that the diffusion of oxygen from the product and stripping gas into the product can take place particularly efficiently.

According to one development, the deaerator can further comprise a drain for the at least partially deaerated product and a stripping gas discharge line and can be configured such that the stripping gas is guided in countercurrent to the product to be deaerated. As mentioned, for this purpose, the inlet for the product can be arranged in the upper region of the container of the deaerator, whereas the drain is arranged in a lower region of the container and defines e.g. the filling level of the product collecting at the base. While the stripping gas feed line is also arranged in the lower region of the container, the stripping gas discharge line is arranged in the upper region of the container, so that a countercurrent of stripping gas forms with respect to the product trickling down in the container. Like in the heat exchanger, the countercurrent principle causes maximum deaeration of the oxygen contained in the product, because the product is always in contact with pure stripping gas at the end of the deaeration process.

According to one further development, the apparatus can further comprise a vacuum pump which is configured to reduce a total pressure within the interior of the deaerator to a pressure below the ambient pressure. For this purpose, the vacuum pump can be regulated, in particular, by the control unit, where a pressure sensor can be provided in the vacuum tank of the deaerator, the data of which is transmitted to the control unit. The control unit and/or the vacuum pump can be configured such that the total pressure in the gas space of the deaerator is reduced to a predetermined vacuum pressure, which makes it possible to deaerate the product at a distance from a boiling point to be set. The magnitude of the distance to the boiling point is mainly dependent on the foaming behavior of the product. If the product foams strongly, a great distance is required (for example, up to 21° C at 60° C deaeration temperature and 500 mbar absolute deaeration pressure). The distance to the boiling point is 2 - 30° C, preferably 3 - 10° C, particularly preferably at 4 - 6° C, for products insensitive to foaming, and preferably 10 - 25° C for products sensitive to foaming. As described above, reducing the total pressure to the predetermined vacuum pressure continuously removes oxygen deaerating from the gas space while stripping gas is continuously supplied so that the partial pressure of the oxygen in the gas space is kept as low as possible. The gas discharged via the vacuum pump can be purified as described above and be reused as stripping gas. In order to maintain a total pressure below the ambient pressure, the deaerator can be formed with a vacuum container, as mentioned above. By adjusting the total pressure, for example, via a controllable vacuum pump, the residual oxygen content in the at least partially deaerated product can additionally be directly influenced. Finally, a throttle device can be provided at the inlet for the product to be deaerated in order to obtain strong expansion of the product upon entry into the deaerator, as a result of which the deaeration of oxygen is accelerated. Such a throttle device can be configured as a screen or a nozzle.

The above objects are also satisfied by a method for producing oxygen-sensitive products, comprising the steps of: feeding product to be deaerated into a deaerator; feeding stripping gas into the deaerator; and withdrawing at least partially deaerated product from the deaerator and successively heating, maintaining heated and cooling the product withdrawn, where the stripping gas is fed directly into an internal space of the deaerator such that the stripping gas contacts the product to be deaerated.

The same variations and developments described above in the context of the apparatus according to the invention for producing oxygen-sensitive products can also be employed for the method of producing oxygen-sensitive products. In particular, the oxygen-sensitive products can be liquid or semi-liquid beverages and suspensions, where in particular fruit juices, fruit beverages, milk, fruit juices with pieces of fruit, flavored water, compotes and jam are comprised.

The successive heating, maintaining hot, and cooling of the at least partially deaerated product can comprise, for example, heating the product withdrawn to a temperature above 60° C, preferably to a temperature above 70° C. Maintaining the heat can comprise holding the heated product at a predetermined constant temperature for a predetermined period of time, for example, for pasteurization. For example, the heated product can be held at the abovementioned temperature for 10, 20, 60 or 90 seconds, preferably at least for 30 seconds. After the phase of maintaining the heat, the product can be cooled to a temperature suitable for carbonation and/or storage and/or filling, for example below 25° C, preferably below 20° C.

The method can further comprise preheating the product to be deaerated to a predetermined temperature, for example, between 40° C and 70° C. In the production of CSD beverages, preheating can be dispensed with in order to obtain improved precarbonation of the beverage in the deaerator.

As described above, the stripping gas can be pure hydrogen or a gas containing hydrogen or carbon dioxide or a gas containing carbon dioxide. A mixture of nitrogen and hydrogen can also be used as stripping gas, in which the proportion of hydrogen is between 1% and 100%, in particular between 50% and 100%. When using carbon dioxide or a gas containing carbon dioxide as stripping gas, pre-carbonation of CSD beverages can be obtained by use of the deaerator. For example, about 1 m<3>of carbon dioxide can be introduced into the deaerator per 10 m<3>of product. The supply of product to be deaerated into the deaerator can be effected continuously with the method according to the invention. Alternatively, the deaerator can be operated in batch mode, whereby a predetermined quantity of product is initially introduced into the deaerator, and is at least partially deaerated by feeding stripping gas. As described above, in particular the oxygen dissolved in the product is replaced with the stripping gas.

According to one special development, the product with the deaeration completed can be carbonated in a carbonator after cooling, where some of the stripping gas is branched off prior to being fed into the deaerator for carbonation. As described above, stripping gas and carbon dioxide or a gas containing carbon dioxide for carbonation, respectively, can originate from the same source. In particular, the stripping gas mixed with oxygen and removed from the deaerator can have the oxygen withdrawn by use of a suitable device, by use of molecular sieves, by distillation according to the Linde method, or by catalytic combustion with hydrogen, for example, on platinum-coated alumina beads. The purified stripping gas can then be fed back to the source and/or the deaerator or the carbonator.

As described above, when using hydrogen or a gas containing hydrogen as stripping gas, the thermal treatment consisting of heating, maintaining the heat and cooling the product withdrawn from the deaerator can comprise a reduction process which further reduces the residual oxygen content in the "at least partially deaerated product", until the "product with the deaeration completed" is present.

According to one development, the deaerator can be evacuated to a pressure below the ambient pressure by continuously withdrawing gas. The pressure in the deaerator can be, for example, between 0.1 and 1 bar absolute, in particular between 0.2 and 0.6 bar absolute. For this purpose, in particular a controllable vacuum pump can be used, as described above. Due to the continuous withdrawal of gas, the partial pressure of oxygen in the gas space above the product in the deaerator is continuously kept low. This allows for a considerable reduction in the residual oxygen content in the product even without great reduction in the total pressure in the gas space. The stripping gas withdrawn and charged with oxygen can be purified as described above.

According to one development, a quantity of stripping gas supplied can be regulated in dependence of a quantity of product supplied and to be deaerated and optionally of a temperature of the product to be deaerated. This can be effected by way of a control unit which adjusts the quantity of stripping gas supplied and product supplied by actuating respective controllable valves and/or controllable pumps. For example, the ratio of the quantity of stripping gas [m<3>/h] relative to the product flow [m<3>/h] introduced into the deaerator can be between 0.01:1 and 1:1, preferably between 0.05:1 and 0.5:1, particularly preferably between 0.08:1 and 0.15:1.

According to one development, the stripping gas can be blown into the product collecting in a base region of the deaerator. The stripping gas is blown in below the filling level of the product, where a device for producing bubbles can be arranged in particular at the end of the feed line for the stripping gas, as described above. By corresponding arrangement of the feed line, the stripping gas can alternatively be blown directly onto the surface of the product collecting in the base region of the deaerator. If the stripping gas is withdrawn via a stripping gas discharge line in the upper region of the deaerator, then the stripping gas is guided in countercurrent to the product, in particular to a trickle film of the product in the deaerator. When the stripping gas is guided in countercurrent to the product trickling down, a particularly large surface area of the product is exposed to the low partial pressure of oxygen in the stripping gas so that the diffusion of oxygen from the product and of stripping gas into the product can take place particularly efficiently.

Further features and exemplary embodiments as well as advantages of the present invention are illustrated below using the figures. It is understood that the embodiments do not exhaust the scope of the present invention. It is further understood that some or all features described hereafter can also be combined with each other in different ways.

Figure 1 shows a principle diagram of an embodiment of an apparatus for producing oxygen-sensitive beverages according to the present invention.

Figure 2 schematically shows a deaerator according to a first embodiment of the present invention.

Figure 3 schematically shows a deaerator according to a further embodiment of the present invention.

Figure 4 schematically shows the connection of a deaerator to an apparatus for producing oxygen-sensitive beverages according to the present invention.

In the figures described hereinafter, like reference numerals denote like elements. For reasons of clarity, like elements are described only upon their first appearance. It is understood, however, that the variants and embodiments of an element described with reference to one of the figures can also be applied to the corresponding elements in the other figures.

Figure 1 shows a principle diagram of an embodiment of an apparatus for producing oxygensensitive beverages according to the present invention. The apparatus presently shown is used, in particular, for the production of fruit juices, CSD beverages, flavored water and similar beverages. However, it is to be understood that the present invention can also be applied to other oxygen-sensitive products, in particular the ones previously mentioned. Respectively needed system components, such as, for example, gently operating displacement pumps for transporting fruit pieces, would be added by the person skilled in the art on account of his expertise.

As indicated by the arrows on the left-hand side in Figure 1, water 102, syrup 104 and flavors 106 are first fed, according to a recipe that depends on the beverage, into a buffer 110 in which the individual components can be, for example, intermixed. In addition to the components added, the mixture generally also contains gas components, in particular oxygen, which can adversely affect the quality of the end product, as described above.

From buffer 110, the mixture is first fed into a preheater 120, in which it is preheated, prior to entering deaerator 100, to a temperature which accelerates the deaeration of oxygen and other undesired components from the product to be deaerated. In the production of CSD beverages, however, preheating can be dispensed with in order to achieve better pre-carbonation of the beverage in the deaerator, as already mentioned.

The product to be deaerated is fed via a line 9 from preheater 120 to an inlet of deaerator 100. The at least partially deaerated product is then discharged from deaerator 100 via a further line 15 which is connected to a drain of the deaerator, and fed to the device for thermal treatment. According to the invention, device 140 for thermal treatment comprises a heater 142, a heat holder 144, and a cooler 146, which successively heat the at least partially deaerated product to a predetermined temperature, maintain it at that temperature for a predetermined period of time and subsequently cool it to a temperature which is suitable, in particular, for carbonation. Heating to a predetermined temperature can be such that pasteurization of the product takes place in device 140 for thermal treatment. Furthermore, by using hydrogen or a gas containing hydrogen as stripping gas, as described above, further reduction of the residual oxygen content in the at least partially deaerated product can be effected by reduction of the oxygen.

The product with the deaeration completed is therefore present at the outlet of device 140 for thermal treatment and is fed via a line 32 to a carbonator 150. Carbon dioxide or a gas containing carbon dioxide, which is dissolved in the product cooled by cooler 146, is fed via a line 30 to the product with the deaeration completed in carbonator 150, which can be designed as a tank. It is understood that carbonator 150 can be dispensed with or bypassed by a bypass line in the case of still beverages. After carbonation in carbonator 150, the now finished beverage is fed to a filling device 160 which fills the beverage into containers, for example, bottles.

For performing the deaeration process in deaerator 100, stripping gas is introduced, in addition to the product to be deaerated, via a line 14 into deaerator 100. A controllable valve 11 can there be provided with which the quantity of stripping gas introduced can be controlled. After replacing the stripping gas with the gases dissolved in the product to be deaerated, the gas mixture present in the gas space of deaerator 100, which contains in particular oxygen, is withdrawn from deaerator 100 via a line 13. A controllable vacuum pump 7 is provided in line 13, by way of which a predetermined total pressure can be set below the ambient pressure in the gas space of deaerator 100.

The gas mixture withdrawn from the deaerator can subsequently be passed either as gas 108 into the ambient air or into a storage container, as indicated by way of three-way valve 25, or supplied to a device 130 for the purification of the gas mixture. In this device 130, oxygen can be extracted, in particular, from the gas mixture, where molecular sieves, a distillation device according to the Linde method, or a device for catalytic combustion with hydrogen can be employed. After withdrawal of the oxygen, the gas mixture can be fed back from device 130 via a valve 26 into stripping gas feed Iine14 or fed via a valve 27 to a source 170 for stripping gas.

According to one development of the present invention, a common source 170 for carbon dioxide or a gas containing carbon dioxide as stripping gas is provided in an apparatus for producing oxygen-sensitive CSD beverages. From this common source 170, the stripping gas is first passed via a common line 31 to a 4-way valve 16 shown by way of example. A portion of the stripping gas is branched off at this valve 16 in order to introduce it into the deaerator via stripping gas feed Iine14. The remainder of the stripping gas is introduced into carbonator 150 via line 30 and/or is blown via line 29 and a valve 28 directly into line 32 toward carbonator 150. It us understood that valves 16 and 28 can be configured according to the respective design of the carbonator, where additional (controllable) pumps can be provided in lines 14, 29 and 30. The use of a common source 170 for the deaeration of the beverage in deaerator 100 and the carbonation of the beverage with the deaeration completed reduces the complexity of the entire system and also saves installation and operating costs.

Instead of carbon dioxide or a gas containing carbon dioxide, pure hydrogen or a gas containing hydrogen can also be used as stripping gas. Alternatively, an inert gas, for example nitrogen, can be used as stripping gas. The alternatives mentioned can be used both in the production of still beverages and also as an additive to the carbon dioxide in the production of CSD beverages. The hydrogen in the stripping gas acts as a reducing agent for the residual oxygen in the at least partially deaerated product during the heating and maintaining-heat phase in device 140 for thermal treatment.

The finished beverage can be passed from device 140 for thermal treatment or from carbonator 150 directly to a filling device 160 or alternatively to a storage tank 160 in which the finished beverage is stored in an inert gas atmosphere.

Figure 2 very schematically shows a deaerator according to a first embodiment of the present invention. Deaerator 100 comprises a container 1, in particular a vacuum container, which comprises a lower region with a base, the diameter of which decreases downwardly. As shown in the figure, the base region can be designed substantially conically. The container can have a volume, for example, from 1 m<3>to 5 m<3>. Provided in the upper region of container 1 is an inlet 2 for the product to be deaerated, via which the product can be introduced into the container.

According to this embodiment, inlet 2 is provided with a distributor device 4 which is designed such that it produces a trickling film 19 of product to be deaerated on a container inner surface. A trickling film is presently understood to be a falling film which flows downwards on a container inner wall in the direction of drain 3. The trickling film is formed below distributor device 4, preferably rotationally symmetrically to the center axis M of container 1. The trickling film can terminate, for example, in a liquid reservoir 42 in the lower region of container 1. The trickling film thickness can be, for example, in a range of 0.1 mm to 1 mm. The trickling film has a particularly large surface to gas space 40 of container 1, via which gas exchange with the stripping gas can be obtained in a particularly effective manner.

In the embodiment shown, a swirl inlet nozzle 4 is provided as a distributor device 4 and is designed to set the incoming product to perform a rotary motion. This results in a thin turbulent trickling film 19 which flows downwardly over the entire inner surface of the container. However, a double screen or a throttle device can also be used as distributor device 4 instead of the swirl inlet nozzle. Alternatively, it is also possible to provide in the upper region of container 1 a ring line which has either several openings disposed on the circumference or an annular gap which guide the product to the inner wall of the container in such a way that the product can run as a falling film or a trickling film down the inner wall of the container.

In addition to inlet 2 and drain 3 for the product, deaerator 100 also comprises a stripping gas feed line 5a in the lower region of the container and a stripping gas drain 6, preferably in the upper region of the container. A counterflow 21 of stripping gas can be produced by the stripping gas feed and drain lines. As is apparent from Figure 2, a gas line 5a projects from the lower part of container 1 into the container. In this embodiment, the opening of gas line 5a, which is closed with a screen or filter 35 for producing bubbles, is arranged at a height which is below a surface level 41, i.e. below the filling level, of product 42 accumulating in the base region of the deaerator The maximum filling level 41 can be determined and adjusted by use of a filling level control device. Stripping gas 21 can enter the product via screen 35 and then into gas space 40 of the container.

The embodiment shown in Figure 3 corresponds to the embodiment shown in Figure 2, with the exception that opening 36 of stripping gas feed line 5b above surface 41 projects downwardly, i.e. toward surface 41 of product 42 collecting in the base region of container 1. Opening 36 is preferably located in the region of the center axis M of the container. When the stripping gas is introduced into gas space 40 via a downwardly oriented inflow opening, the advantage arises that also surface level 41 of the product is "blown off' in the lower region of the container, as a result of which oxygen can be increasingly deaerated. In the variant shown in Figure 2, the formation of bubbles of stripping gas rising in liquid 42 promotes the dissolution of stripping gas in the product and thus also the deaeration of oxygen.

The stripping gas can be introduced into container 1 at ambient temperature or expansion temperature, but generally not cooled. This facilitates the previously described recycling of stripping gas by way of device 130 for the withdrawal of oxygen. The volumetric flow of stripping gas can be regulated in dependence of a temperature of the product to be deaerated, the initial content of oxygen, the product and/or the vacuum in container 1.

Figure 4 schematically shows the connection of a deaerator 100 to an apparatus for producing oxygen-sensitive beverages according to the present invention. As already mentioned, the stripping gas is introduced the container 1 of deaerator 100 via a line 14, a controllable valve 11, and stripping gas feed line 5, and is withdrawn from container 1 via controllable vacuum pump 7, through stripping gas discharge line 6 and line 13. The stripping gas withdrawn and charged with oxygen can be fed to the above-mentioned device 130 for the withdrawal of oxygen.

The product to be deaerated is delivered via a line 9 and a controllable valve 10 to inlet 2 and distributor device 4. The trickling film trickling down on the inner wall of the container collects in lower region 3 of container 1, where a pressure sensor 33 is provided in this region according to the present embodiment, by use of which the filling level of the product can be determined. The pressure measured is then passed to a regulator 45 which actuates control valve 10 in line 9 and thus sets a desired volumetric flow of product to be deaerated. The at least partly deaerated product is drained via a drain valve 22 in a drain line 15 by use of a controllable pump 18. Control valve 22 can also be adjusted in dependence on the pressure measured by pressure sensor 33 in such a way that a certain filling level is set. With a controlled filling level, the product to be deaerated is then continuously fed and drained. Arranged in line 15 can be a further control valve 46 via which liquid from the container (for example, cleaning liquid) can be discarded via channel 23.

The quantity of product withdrawn can also be effected by controlling pump 18, where a control unit 24 is provided which controls the pumping capacity of pump 18. Control unit 24 can also perform filling level control or actuation of control valve 10 and actuation of vacuum pump 7. Control unit 24 receives as input data the temperature of the incoming product measured by temperature sensor 8 in line 9 and/or the total pressure measured with pressure sensor 34 in the gas space of container 1. Depending on the temperature measured and/or the total pressure measured, control unit 24 can control the inflow of stripping gas and product to be deaerated, in particular, by regulating control valve 11 and the control valve 10, in such a way that optimum deaeration of oxygen from the trickling film is obtained., Vacuum pump 7 can be controlled by control unit 24 in such a way that the partial pressure of oxygen in the atmosphere in the gas space of container 1 is always so low that a predetermined residual oxygen content is always undershot in the product withdrawn via drain line 15. Control unit 24 can regulate control valves 10 and 11 as well as pumps 7 and 18 by way of empirical measurement curves, which guarantee a residual oxygen content below a predetermined threshold value.

According to the embodiment shown, provided in the upper region of container 1 are also a condensate return flow protection 50 and a condensate line 12 via which any condensate possibly arising can be discharged via a drain 23. Finally, Figure 4 shows a bypass valve 17 for bypassing deaerator 100, if required.

The devices shown allow the oxygen content to be reduced considerably, in particular for highly foaming CSD beverages, even without large vacuum capacities, so that the filling capacity can be respectively increased. The use of a common source of carbon dioxide or a gas containing carbon dioxide allows for a particularly simple and compact structure of the system as well as a reduction in the installation and operating costs of the system.

Claims (13)

1. Apparatus for producing oxygen-sensitive products comprising: a deaerator (100) with an inlet (2) for a product to be deaerated; a device (140) disposed downstream of said deaerator for the thermal treatment of the at least partially deaerated product, comprising a heater (142), a heat holder (144), and a cooler (146); a source (170) of carbon dioxide or a gas containing carbon dioxide for use as stripping gas; and a carbonator (150) for the product with the deaeration completed, downstream of said device (140) for the thermal treatment of the at least partially deaerated product; where said deaerator (100) comprises a stripping gas feed line (5) for introducing said stripping gas directly into an interior of said deaerator; and where said carbonator (150) and said stripping gas feed line (5) are connected to said source (170) of carbon dioxide or a gas containing carbon dioxide via feed lines (14, 30, 31).

2. Apparatus according to claim 1, where said source (170), in addition to carbon dioxide, also provides hydrogen or a gas containing hydrogen for use as stripping gas.

3. Apparatus according to claim 1 or 2, where said stripping gas feed line (5a) is arranged in a base region of said deaerator (100), in which said product (42) collects up to a filling level (41), such that an opening (35) of said stripping gas feed line (5a) is below said filling level (41).

4. Apparatus according to claim 1 or 2, where said stripping gas feed line (5b) opens into said deaerator (100) such that said stripping gas enters said deaerator above a filling level (41) of product (42) collecting in a base region of said deaerator through a downwardly facing opening (36) of said stripping gas feed line (5b) located in a region of a center axis of the deaerator (100).

5. Apparatus according to one of the preceding claims, where said deaerator (100) is configured as a film deaerator, in particular as a trickling film deaerator.

6. Apparatus according to one of the preceding claims, where said deaerator (100) further comprises a drain (3) for said at least partially deaerated product and a stripping gas discharge line (6) and is further configured such that said stripping gas is guided in countercurrent (21) to said product to be deaerated.

7. Apparatus according to one of the preceding claims, further comprising a vacuum pump (7) which is configured to reduce a total pressure within the interior of said deaerator (100) to a pressure below the ambient pressure.

8. Method for producing oxygen-sensitive products, comprising the steps of: feeding product to be deaerated into a deaerator (100); feeding stripping gas into said deaerator (100); and withdrawing at least partially deaerated product from said deaerator (100) and successively heating, maintaining heated, and cooling said product withdrawn; where said stripping gas is fed directly into an internal space of said deaerator such that said stripping gas contacts said product to be deaerated; where said product with the deaeration completed is carbonated in a carbonator (150) after cooling; where a portion of said stripping gas is branched off prior to being fed into said deaerator (100) for carbonation of said product with the deaeration completed in said carbonator (150); and where said stripping gas is carbon dioxide ora gas containing carbon dioxide, in particular in combination with hydrogen.

9. Method according to claim 8, where said product to be deaerated is preheated prior to being fed into said deaerator (100).

10. Method according to claim 8 or 9, where said deaerator (100) is evacuated by a continuous withdrawal of gas to a pressure below the ambient pressure.

11. Method according to one of the claims 8 to 10, where a quantity of stripping gas supplied is regulated in dependence of a quantity of product supplied and to be deaerated, and optionally of a temperature of said product supplied and to be deaerated.

12. Method according to claim 11, where the volumetric flow ratio of the quantity of stripping gas supplied relative to the quantity of product supplied and to be deaerated is between 0.01:1 and 1:1, preferably between 0.05:1 and 0.5:1, particularly preferably between 0.08:1 and 0.15:1.

13. Method according to one of the claims 8 to 12, where said stripping gas is introduced into a gas space (40) of said deaerator (100) via a downwardly oriented inflow opening (36) such that the introduced stripping gas directly impacts a surface level of said product (42) collecting in a base region of said deaerator (100).