EP0422669A1 - Method and apparatus for the creation and preservation of aseptical conditions in a tank park - Google Patents

Abstract

The invention relates to a method and apparatus for creation and preservation of aseptical conditions in a tank park for the storage of foods in preserved, pumpable form, at least one storage tank being cleaned, sterilised, filled with inert gas, filled under aseptical conditions with the product to be stored and under aseptical conditions at least partially emptied. In order to be able to automate all these processes and on the one hand to improve operational safety and on the other hand to prevent any recontamination of the sterilised products to be stored, it is proposed according to the invention that all mass flows, which are supplied to each storage tank (1 ... 80), and the stored product, which is removed from each storage tank, are conducted by at least one mobile device (W1, W2, W3) which is connected detachably on the one hand to stationary supply and removal lines (105) and on the other hand detachably to at least one storage tank (1 ... 80), and that the at least one mobile device has means for measuring, controlling and regulating the throughput, the pressure and for controlling the temperature and means for sterilising the masses flowing through it. The invention allows computer-controlled automatically monitored process management. <IMAGE>

Description

The invention relates to a method and a device for generating and maintaining aseptic conditions in a tank system for the storage of food in a preserved, pumpable form. In the method, at least one storage tank is cleaned, sterilized, filled with sterile gas, filled with the product to be stored under aseptic conditions and at least partially emptied under aseptic conditions. The device has at least one storage tank and stationary supply and disposal lines for the supply and discharge of stored or stored product as well as for the supply of steam, inert gas, compressed air, water and possibly liquid sterilizing agents.

Such methods and devices are known, for example, from US Pat. Nos. 4,287,821 and 4,325,296. The ones described there However, methods and devices have the disadvantage that each individual aseptic tank is connected directly to fixed pipelines through which cleaning and sterilizing agents, steam, inert gas and the product to be stored are supplied to the individual tanks and through which the tanks are emptied. Since the gases required for generating and maintaining aseptic conditions, such as steam, inert gas and sterilized compressed air, are fed to the aseptic tanks under low pressure via sometimes very long lines into the tanks, and since almost exclusively manual valves are used, the known methods and devices both exist the risk of the tanks imploding due to vacuum formation as well as the risk of exploding because of insufficient control of the flow rate, the pressure and the temperature of the masses flowing into or withdrawn from the tanks.

Since the masses supplied to the aseptic tanks are preserved in the known methods and devices before they are fed into the fixed pipeline network, there is also the risk that the sterilized gases or products will be recontaminated with germs due to leaks within the pipeline network and the fittings they reach the aseptic tank.

The tank systems of the type described here are used in particular for the storage of fruit and fruit juices and fruit and fruit purees, for example peach, apricot, apple, pear and tomato products, these products being stored until they gradually after can be further processed to produce finished products. The individual aseptic storage tanks usually have a capacity of between 25,000 and 75,000 liters, and tank farms with farm capacities of several million liters are formed from a large number of such storage tanks. The aseptic tanks are usually welded together from stainless steel sheets, the tanks being about 6 to 10 m high to reach. These large tanks are usually only pressure-resistant up to a maximum pressure of 1.5 x 10⁵ Pa (1.5 bar).

To create and maintain aseptic conditions in a tank system of the type mentioned for the storage of food in a preserved, pumpable form, the procedure has hitherto generally been as follows:

The tanks were first cleaned by hand using pressure pumps and gimbal cleaning heads with cold or hot water and suitable cleaning agents and then sterilized with steam, the steam temperature and the duration of the steaming being empirically determined and manually monitored. After steaming and stripping the condensate, nitrogen was blown into the tanks. When the atmosphere in the tanks of steam and inert gas cooled, there was a risk of imploding due to the formation of negative pressure if the pressure or the quantity of the inert gas supplied were insufficient. Additional risks resulted from the use of manual valves and manual switching and the lack of monitoring of the respective valve positions. Another disadvantage was the uncontrolled blowing of a cold stream of inert gas onto the hot inner surfaces of the tank, which often led to the destruction or damage of the tanks if the operating personnel reacted too slowly.

The inert gas-filled tanks were generally left to stand for a few weeks before they were loaded with the product to be stored in order to be able to check the pressure resistance and tightness.

Immediately before the tanks were filled, the supply lines between the pasteurization and / or sterilization system upstream of the tank system and the aseptic storage tanks were sterilized with steam, the temperature and sterilization duration again being monitored manually. Forming Kon condensate had to be completely removed in order to achieve at all critical points, the "SIP" temperature ( "S terilisation- I n P lace"). Immediately after the sterilization of the supply lines "on site", the filling of the tanks was started, since cooling after the SIP had ended would lead to negative pressure in the pipelines, which in turn would lead to recontamination due to germs entering from outside. To fill with the product to be stored, the gas escape valves of the tanks had to be opened in order to avoid compressing the inert gas contained in the tanks above a pressure of maximum 1.2 x 10⁵ Pa. The fill level had to be observed on the viewing panes in the upper part of the tanks, and when the target level was reached the product inlet valve was closed and either the pump was switched off or the supply line to another aseptic tank was opened. At the same time, the gas escape valves had to be closed to prevent the ingress of air and therefore germs. Above the product stored in the tanks was a small expansion space filled with inert gas, which should be kept under an overpressure of approximately 0.5 x 10⁵ Pa.

The stored juices and purees, which separate relatively quickly as the solid pulp content sinks, are emptied either non-sterile after cooling to 0 ° C in tanker trucks, or aseptically sterile in a sterile transport tank truck or container or in a filling system using a pasteurization system and normal cooling . The loading of the aseptic chamber of a filling system and the aseptic filling as such was carried out, for example, using devices and methods as are known from EP-B-0 180 540.

With the known method described above, the contents of various aseptic storage tanks were mixed under aseptic conditions, the aseptic partial removal with simultaneous mixing of the entire tank contents, sterile pumping from one tank to the next, sterile metering of similar or different products or additives with simultaneous mixing of the tank contents under aseptic conditions and a fully automatic, computer-controlled process control not possible.

The invention is therefore based on the object of improving and developing a method and a device of the type mentioned at the outset in such a way that the entire process control can be controlled in an automated and computer-controlled manner and that the risk of implosion or explosion of the storage tanks and the risk of recontamination of the tanks and the stored products are reduced and the operational safety of the entire system is improved. The method and the device are further to be improved and developed in such a way that they mix the contents of different aseptic storage tanks under aseptic conditions, the aseptic partial removal with simultaneous mixing of the entire tank contents, the sterile pumping from one tank to the other, the sterile metering of one Allow sterilized product or additive while mixing with the tank contents.

This object is achieved in the method of the type mentioned at the outset in that all mass flows which are fed to each storage tank and the stored product which is removed from each storage tank are guided by at least one mobile device which, on the one hand, has a fixed supply and Disposal lines and on the other hand is detachably connected to at least one storage tank, and that the at least one mobile device has means for measuring, controlling and regulating the flow rate, the pressure and for controlling the temperature, and means for sterilizing the gaseous masses flowing through it.

In connection with the invention, the term "mass flows" is to be understood to mean all fluids which are fed to the aseptic tanks, that is to say all gases such as steam, inert gases, including them preferably carbon dioxide and nitrogen, sterilized compressed air, liquids such as water, fruit juices, vegetable juices or other liquid foods, possibly liquid sterilizing agents, as well as pumpable food products, the liquid and solid components, such as fruit and vegetable purees, and optionally gaseous components, e.g. CO₂ and cell gases.

The products to be stored in the aseptic tanks must have been pasteurized and / or sterilized in a manner known per se before they are fed into the stationary supply lines. The methods and devices used for this are not the subject of the invention. The foodstuffs to be stored preferably contain no preservatives, stabilizers or other substances that are added after the fruits have been harvested.

By using at least one mobile device, which is preferably designed as a movable carriage, the constructional and equipment outlay required for the construction of such a tank system or tank farm is considerably reduced. The permanently installed supply and disposal lines no longer need to be routed to each individual aseptic tank and firmly connected to the inlet and outlet valves of the individual tanks, but it is sufficient to place the fixed supply and disposal lines only at one or a few locations in the To run tank farm. The few transfer points of the stationary line system formed by shut-off devices serve as connection points for detachable, flexible connections, for example pressure hoses, to the respective mobile device, which can be guided or driven to the storage tank or to a group of storage tanks, on which or at which an operation is about to be performed. The mobile device is then also connected to the via releasable, flexible or fixed connections, preferably pressure hose or pipe connections processing storage tank or the group of storage tanks to be processed.

The decisive advantage achieved by the invention is that the mobile device itself has both means for measuring, controlling and regulating the flow rate, the pressure and for controlling the temperature of the gases, liquids and other masses flowing through the mobile device, as well as means for Containing sterile all masses flowing through the mobile device. These means of course also include all the pumps and fittings required to control and regulate the flow rate and pressure of all fluids flowing through the mobile device and to control the temperature of these fluids. All of these agents are known per se to the person skilled in the art.

By combining the means for measuring, controlling and regulating the flow rate, the pressure and for controlling the temperature and the means for sterilizing the mass flows supplied to or removed from the storage tanks within the mobile device, such operations can also be carried out with comparatively little expenditure on equipment Carry out under aseptic conditions that have hitherto been difficult or impossible to carry out under aseptic conditions, namely, for example, mixing the contents of different tanks, removing aseptically only part of the contents of a tank while mixing the entire contents of the tank, and pumping sterile from one Tank to another or the sterile dosing of products while mixing the tank contents. In this case, only a single mobile device can be used for a certain number of aseptic tanks for all operations to be carried out, or several mobile devices can be used for a certain group of tanks, which then each take on different tasks. For example, a first mobile device can be used through which only gaseous mass flows and are thereby sterilized, regardless of whether they flow from the fixed pipeline network into the tanks or vice versa from the tanks to the stationary pipeline network or whether they are taken from just one or more tanks, flow through the mobile device and be returned to one or more tanks from here. A second mobile device can only be used to take the product to be stored, for example fruit juice or tomato puree, from the fixed pipeline network and to pump it into the aseptic tanks or vice versa from the aseptic tanks to the fixed pipeline network or from one or more specific ones Take over tanks and pump them back into one or more tanks (mixing, homogenizing, pumping over). Finally, a third mobile device can be used as a mobile intermediate station for water, cleaning agents and liquid sterilizing agents, which are taken over by the fixed pipeline network and fed to one or more storage tanks for the purpose of cleaning and sterilizing the tanks. Whether only one mobile device or several mobile devices are used for a certain number of tanks depends on the special circumstances of the respective tank system, the type of products to be stored and the individual wishes of the operators of the respective system.

In an advantageous embodiment of the method according to the invention, the stored product is mixed or homogenized under aseptic conditions by removing it from at least one storage tank, guiding it through the at least one mobile device and pumping it back into at least one storage tank. Each of the mobile devices is designed so that the stored product either from one tank to several tanks, from several tanks to one tank, from one tank to the same tank, from several tanks to the same tanks, from one tank to another Tank or multiple tanks can be pumped into several other tanks. The detachable connections between the tanks and the mobile device make all conceivable combinations possible.

According to another advantageous embodiment of the method according to the invention, the stored product is mixed with aseptic conditions and mixed with at least one other sterile product by the first product to be stored flowing through the at least one mobile device either during the filling of the at least one storage tank or during the mixing , Homogenizing or pumping the first product within the mobile device, the at least one other sterile product being metered in under aseptic conditions. The product to be metered in is located in a special container inside or outside the tank system and is fed to the mobile device via a detachable connection, preferably a hose connection, and is fed there into the flow path of the product to be stored by means of devices known per se.

The filling and complete or partial emptying of the at least one storage tank and the mixing, homogenizing, pumping and metering in of the product (s) to be stored is preferably carried out under a sterilized protective gas atmosphere, with CO₂, N₂ and inert gas mixtures being preferred as inert gases.

In a further advantageous embodiment of the method according to the invention, the cleaning, sterilizing, filling with inert gas, filling with the product to be stored and the at least partial emptying of the at least one storage tank, mixing, homogenizing, pumping over and metering in the product (s) to be stored ) and the maintenance of a sterile protective gas atmosphere by a process computer or an electronic data processing system controlled or monitored semi or fully automatically, the means for measurement, control and regulation as well as for sterilizing contained in the at least one mobile device are likewise computer-controlled and monitored.

All computer-controlled processes are preferably recorded digitally and / or analogously and the process data obtained in this way is stored electronically.

The object on which the invention is based is achieved in the establishment of the type mentioned at the outset for the generation and maintenance of aseptic conditions in a tank system for the storage of food in preserved, pumpable form by at least one mobile device which, on the one hand, is connected to the fixed supply and disposal lines and on the other hand is detachably connected to at least one storage tank and has the means for measuring, controlling and regulating the flow rate, the pressure and for controlling the temperature and means for sterilizing the gaseous masses flowing through it.

As already mentioned, the use of a mobile device according to the invention, which can be detachably connected to one or more different storage tanks, preferably via hose connections, not only reduces the outlay on equipment for the entire tank system, but also reduces it improves the accessibility of the individual tanks and the monitoring options for all operations to be carried out. Above all, however, the risk of recontamination of sterilized equipment and already sterilized products is reduced in that all mass flows from and to the aseptic tanks are first led through the mobile device, which, thanks to their mobility, can be brought into the immediate vicinity of each individual tank. Since the mobile device contains means for sterilizing all the gases flowing through it, these are inevitably sterilized each time they pass through the mobile device. As a result, not only the aseptic Be conditions are maintained in an almost ideal way, but thanks to the optimally short distances between the mobile device and aseptic tanks, the risk of recontamination due to germs entering from outside is drastically reduced.

The mobile device is preferably designed to be movable. For example, the mobile device can be a frame or a trolley provided with rollers or wheels, in which said means for measuring, controlling and regulating the flow rate, pressure and temperature as well as the means for sterilizing the masses flowing through, including all associated fittings, Pumps, measuring instruments, switching elements, sensors, etc. are mounted. The mobile device in the form of a carriage can be moved manually or driven by a motor. It can also be a rail vehicle that can be controlled and moved manually, semi-automatically or fully automatically. Not only systems moving on the floor, but also systems hanging on rails are conceivable, which can be moved floating above the individual storage tanks.

In order to be able to reach as many storage tanks of a tank farm as possible with the smallest possible number of mobile devices, it is advantageous if the fixed supply and disposal lines have several connection points for the connections between the respective mobile device and the fixed line network, which at the same time has the required length of connections is reduced.

The stationary supply and disposal lines are particularly advantageously designed as ring lines which enclose the tank system or tank farm. A separate ring line can be provided for each individual product or each flowing medium, but preferably only a single ring line with stub lines is arranged for the gaseous fluids, namely steam, inert gas and compressed air. through which one of these gases is extracted one after the other as required.

If the tank system is a tank farm with a multiplicity of aseptic storage tanks, the individual tanks are preferably arranged in groups such that each tank is freely accessible for the at least one mobile device.

• Fig. 1 ist ein Grundriß einer Tankfarm mit insgesamt 80 Aseptik-Lagertanks;
• Fig. 2 zeigt schematisch einen Teilbereich der Tankfarm ge­mäß Figur 1, wobei Tank Nr. 15 gereinigt wird und die Tanks Nr. 7 und 8 sterilisiert, mit Inertgas gefüllt und schließlich unter aseptischen Bedingungen mit dem einzulagernden Produkt befüllt und entleert werden.
• Fig. 3 zeigt schematisch denselben Teilbereich der Tankfarm gemäß Fig. 1, jedoch in anderer Funktion, wobei die Tankpaare 6+8 und 16+28 sterilisiert und mit Steril­gas befüllt werden.

The invention is further explained below using exemplary embodiments in conjunction with the drawing:

• Fig. 1 is a plan of a tank farm with a total of 80 aseptic storage tanks;
• 2 schematically shows a portion of the tank farm according to FIG. 1, tank No. 15 being cleaned and tanks No. 7 and 8 being sterilized, filled with inert gas and finally being filled and emptied with the product to be stored under aseptic conditions.
• 3 shows schematically the same section of the tank farm according to FIG. 1, but in a different function, the tank pairs 6 + 8 and 16 + 28 being sterilized and filled with sterile gas.

The tank farm 100 (FIG. 1) comprises 80 aseptic storage tanks (1 ... 80), which are arranged in rows of 10 or double rows of 20. The rows of tanks are so far away from the walls or surrounding walls 101 of the tank farm 100 that passages 102, 103 of several meters in width remain free on all sides. Corresponding gears 104 are also between the rows or double rows of tanks 1 ... 80. All these gears are dimensioned so that they can be easily driven on with the mobile units W₁, W₂, W₃. At least three fixed ring lines 105 are installed along the walls 101 for the supply and discharge of the goods to be stored or loaded arranged product as well as for the supply of steam, inert gas, compressed air and water and, if necessary, liquid sterilizing agents. All ring lines 105 begin or end in a central operating station 106, in which steam, inert gas, preferably CO₂ or N₂, compressed air, water, optionally liquid sterilizing agent, the pre-pasteurized and / or pre-sterilized product to be stored, for example tomato puree, are fed into the respective ring lines , in which the stored product removed from the tanks either arrives or is removed for further processing or for forwarding to a bottling plant and in which there is preferably an electronic data processing system in the form of a computer, through which all process parameters and all operational processes required for generation and Maintaining aseptic conditions at every stage of the treatment of the food to be stored is required to be monitored and controlled. The ring lines 105 have a number of connection points 107, preferably in the form of aseptic valves, which can be detachably connected to connecting lines 108. The pressure lines 108 lead to a mobile device W₁ ... W₃, with which they are also releasably connected.

The mobile devices W₁ ... W₃ are on wheels or rollers, rail-bound or non-rail-bound, movable in the aisles 102, 103, 104 and they contain means for measuring, controlling and regulating the flow rate, the pressure and for controlling the temperature and Means for sterilizing the gaseous masses flowing through them. The mobile devices W₁ ... W₃ are also releasably connected to one or more of the aseptic storage tanks 1 ... 80 by means of pressure lines 109.

The method according to the invention and its application and the device according to the invention will now be described in more detail with reference to FIG. 2, namely during cleaning, sterilization and filling of the tanks with inert gas, during loading filling with the product to be stored as well as during the mixing or homogenization of the stored product, during the transfer pumping of the stored product from one tank into the other and during the complete or partial emptying of a tank.

The aseptic storage tanks are first cleaned with cold or hot water and suitable cleaning agents. In the illustrated embodiment, the water is taken from one of the three fixed ring lines 105 at the connection point 107a, fed via the connecting line 118 to the mobile unit W₃ and from there via the pressure line 119 into the storage tank 15, which, like the other storage tanks, does not consist of stainless steel and has a capacity of between 25,000 and 75,000 liters.

The tanks 7 and 8, which have already been cleaned in the manner described above using the mobile device W₃, are sterilized using the mobile device W and filled with inert gas or the desired atmosphere. For this purpose, the mobile device W 1 is connected via the pressure hose 128 at the connection point 107 to the fixed ring line 105 through which steam (superheated steam) flows under high pressure. The steam passes within the mobile device W 1, the means installed therein for measuring, controlling and regulating the flow rate, the pressure and for controlling the temperature of the steam and at least one sterile filter and is then through the pressure hoses 129, 129 'in the storage tanks 7 and 8 guided. The pressure and temperature and the duration of the damping are controlled and monitored by the process computer in the central station 106. The electronic means, switching means, sensors, etc. required for this are known per se to the person skilled in the art and do not require any further explanation here. After the automatically controlled termination of the steaming, inert gas, preferably CO₂ or N₂, is automatically blown into the tanks 7, 8 via the same lines 129, 129 '. The Inert gas is taken from one of the ring lines 105 at the connection point 107 and supplied via the pressure hose 128 to the mobile unit W 1. The tanks filled with inert gas remain after cooling for some time before the condensate is drawn off and they are filled with the product to be stored in order to check the pressure resistance and tightness of the tanks. Before filling the aseptic storage tanks 7, 8, the stationary product line 105 from the pasteurization system and the entire supply line (connection point 107, supply line 138, mobile device W2, supply lines 139) are steam-sterilized under control of the program of the mobile device W1 and then cooled with inert gas, and simultaneously with the pressure lines 129, 129 'and the tank fittings. Then and for filling the aseptic storage tanks 7, 8 with the product to be stored, the latter is withdrawn from the fixed ring line 105 at the connection point 107 and supplied via the flexible hose line 138 to the mobile device W 2. There the product to be stored passes through the means for measuring, controlling and regulating the flow rate, the pressure and for controlling the temperature of the product and then passes into the flexible hose line 139, via which it is fed to the tanks 7 and 8 simultaneously or in succession. At the same time, the nitrogen or other inert gas pressure is maintained via the lines 129, 129 'during the filling of the tanks via the mobile device W 1, so that the entire filling process takes place while maintaining aseptic conditions.

Since the stored fruit and vegetable products separate very easily during storage in the tanks, because pulp and other solid components settle on the bottom of the tanks, the stored product is mixed sterile when necessary, either with the contents of a single tank themselves or the contents of different tanks among themselves. For the purpose of sterile mixing of the contents of the tank No. 7, the tank content is supplied via the flexible hose line 131 to the mobile device W₂ and via the Pumped line 139 back into tank No. 7. To mix the contents of the two tanks No. 7 and No. 8, depending on the filling level of the two tanks, the product from tank No. 8 is fed via line 130 to the mobile device W₂ and from there via line 131 into the Pumped No. 7 tank or it is the tank content of tank No. 7 reversed supplied via line 131 to the mobile device W₂ and pumped via line 130 into tank No. 8. For the purpose of mixing or homogenizing the contents of the tanks 7, 8, this process can be repeated as often as desired in both directions. All process parameters are also automatically controlled and monitored by the process computer in the central station 106.

To completely pump the contents of, for example, the tank No. 8 into the tank No. 7, the tank content of the tank 8 is pumped via the hose line 139 into the mobile device W₂, from where it reaches the tank 7 via the hose line 131. Conversely, the contents of the tank 7 can be pumped into the tank 8 via the hose line 139 and the mobile device W 2 and the hose line 130. During the entire process, the inert gas pressure in the tanks 7, 8 is kept constant via the mobile device W 1 and the lines 129, 129 '.

For complete or partial emptying of a tank, in the illustrated embodiment of the tank 7, the tank content is pumped via the flexible line 139 into the mobile device W₂ and passes via line 138 into the stationary product ring line 105, through which it is sterile to the central station 106 is supplied. Here too, aseptic conditions are constantly maintained by simultaneous injection of inert gas into the tank 7 via the mobile device W 1 and the line 129, 129 'and continuously controlled and monitored via the central process computer in the central station 106.

If the product to be stored is in the process of being filled Tanks another sterile product, which may be the same or different from the first product to be stored, should be metered in under aseptic conditions, the first product is, as described above, removed from the fixed ring line 105 and via the hose line 138 of the mobile device W₂ fed. The mobile device W₂ at the same time the pre-pasteurized and / or pre-sterilized product to be metered in, for example an aroma, ascorbic acid or the like, is fed from a separate storage container via a hose line as a second sterile product. At least the second product is re-sterilized in the mobile device W₂ by means of the sterilizing agent therein, for example a sterile filter, during its passage through the mobile device W₂ and at the same time mixed homogeneously with the first product. The mixture thus formed is then pumped through the hose line 139 into the tanks 7, 8 simultaneously or successively. During these operations, a protective gas atmosphere is maintained in the tanks 7, 8 by blowing in an inert gas via the mobile device W 1 and the hose lines 129, 129 '. All of these processes are automatically controlled and monitored by the process computer in the central station 106.

In all of the processes described, the computer-controlled process control and monitoring ensures that no damage can occur in the aseptic tanks and all fittings, lines and units due to negative pressure (risk of implosion) or excess pressure (risk of explosion). The process computer also ensures the maintenance of the required inert atmosphere, for the automatic filling of the tanks with predetermined amounts of products to be stored by level control, for the automatic sterile removal by controlling and monitoring the flow rates, etc. All processes are logged and the process data obtained electronically saved.

The by the inventive method and the fiction Adequate set-up enables sterile mixing of the sterilized product in the aseptic storage tanks is important in order to obtain a homogeneous mass, since the processed products (fruits, fruits, vegetables) are not of a constant nature, but rather in the degree of ripeness, sugar and Acidity, differentiate by defects of various kinds. The homogeneity of the stored product is also important, for example, when analyzing the total content of a storage tank with a capacity of 50,000 liters. Without sterile mixing, stratifications occur within the tank filling, which either make the analysis of the tank content completely impossible or falsify it. For the same reasons, it is necessary to mix the tank contents under sterile, aseptic conditions at the time the product is removed, and for the first time sterile is possible with the aid of the method and the device according to the invention.

Even the sterile pumping from one tank to another only makes sense if the contents of each tank have been mixed and homogenized beforehand, because it is only possible to analyze the tank contents and to have the knowledge required to blend the contents of different tanks win. This also applies in a corresponding manner to the sterile partial removal from the storage tanks and to the sterile metering and mixing with an additive or a second product.

The invention also enables the automatically monitored, sterile filling of the aseptic storage tanks with quantity preselection and / or probe switching, the quantity preselection being very important during filling, partial removal or emptying. This results in considerable personnel savings, seamless control of all process steps and facilities, as well as constant control and monitoring of the inventory. The preselected quantities are checked by means of an overfill protection device, namely by a prewarning signal, which is triggered by an appropriate probe or a measuring sensor It is released shortly before the preselected fill level is reached, while the quantity supply is automatically stopped by a second signal, the "full signal".

Another advantage achieved according to the invention is that the stationary supply and disposal lines can be operated under high pressure and the pressure can only be reduced in the respective mobile device, that is to say close to the respective storage tank. Among other things, this leads to a reduction in the risk of recontamination. The risk of recontamination is also reduced by the fact that not only the inflowing gases, but also the outflowing gases, including air and water vapor, can be subjected to sterile filtration in the respective mobile device.

The invention also offers the possibility of saving inert gas (for example nitrogen). For this purpose, after steam sterilization, the sterile tank is filled with sterile-filtered air and kept under pressure until it is filled. The sterile air is displaced by the inflowing product. It escapes via the mobile unit W1 and the sterile filter installed on it. After filling the tank with product, sterile inert gas is introduced into the product under pressure via the mobile unit W2 and the product line 139 from the mobile device W1 via a sterile connecting line. This sterile gas rises through the tank contents to the free expansion space in the upper part of the product tank and displaces the sterile air, which escapes from the W1 through the sterile filter and pressure regulators. Pressure and quantity are preselected and are automatically controlled by the mobile unit W1. This method is particularly suitable for products that are not very sensitive to oxidation or for short storage times. The savings in inert gas are very significant. The venting effect in the product when using nitrogen for blow-by (sparging) is known and is used in this process.

The blowing process can take place during the filling, also e.g. only in the last third or tenth of the tank capacity, depending on the selected program.

Another advantage of using sterile air for tank pressure (pre-filling) is that in the event of a leak that requires the tank to be opened, the entire inert gas filling is not uselessly lost, but only the sterile air needs to be replaced.

For large tank farms with numerous sterile tanks, there is the need to automatically sterilize several tanks at the same time and fill them with sterile gas, without any personnel expenditure, e.g. over night. This can be accomplished via special devices and controls with the mobile unit W1, as will be described in more detail below in connection with FIG. 3, in which the same parts are provided with the same reference numbers as in FIG. 2:

Tanks 6 + 8 and 16 + 28 must be sterilized and filled with sterile gas. The mobile unit W1 is connected to the ring line 105 for gas and steam, the tanks 6 + 8 via a line 229 to an expansion vessel E1 and the tanks 16 + 28 via a line 229 'to a second expansion vessel E2. The tank gas valves are opened on all tanks. The product valves (bottom valves) are also opened and the tanks 6 + 8 and 16 + 28 connected to each other via product lines 239, 239 '. This product lines 239, 239 'contain for each pair of tanks an automatically controlled by W1 valve AV, which is closed in the idle state.

If the gas and steam pressure have the desired value or have been set, the computer-controlled automatic program is triggered. Steam initially flows through W1 and via the expansion vessel E1 in a uniform volume flow via lines 229 into tanks 6 + 8.

The automatically controlled bottom valve for the connected tanks 6 + 8 opens until the air has escaped from the tanks, then it almost closes, only condensate and a small amount of steam escape continuously during the entire SIP process. The tank internal pressure and thus also the temperature increase until the predetermined temperature or the predetermined pressure is reached at the beginning of the SIP program. After the SIP time has elapsed, the steam flow changes from tanks 6 + 8 to tanks 16 + 28, where the same process (SIP program) now takes place. The tanks 6 + 8, on the other hand, are already filled with sterile gas, the automatic floor valve is completely closed and the pressure is continuously monitored. After the SIP program in tanks 16 + 28 has expired, these are also automatically filled with sterile gas.

The only work of the personnel consists in closing the tank valves (after cooling) and loosening the connecting lines. The SIP can be checked at any time by recording the program duration, temperature, pressure and flow.

If this work is carried out at night, the mobile unit is available for filling, emptying, etc. during the day. Any number of tanks can be sterilized simultaneously, as long as sufficient sterile gas and steam are available.

The use of the expansion vessels E1, E2 enables an even steam distribution.

Until now, it was only possible for the operating personnel to manually sterilize a maximum of 2 tanks next to one another and to fill them with sterile gas, the pressure constantly having to be monitored and the manual valves having to be readjusted. A SIP, gas filling and cooling program takes 4 to 6 hours for a 50,000 l tank. Carelessness could lead to the implosion or rupture of a rupture disc. The personnel expenditure was huge and the sterility of the tanks was solely dependent on the staff; Time, temperature and pressure were only monitored with the watch and optically, without any recording. The same was true for filling and emptying the tanks. All these disadvantages are eliminated according to the invention.

Claims (14)

1.Procedure for creating and maintaining aseptic conditions in a tank system for the storage of food in preserved, pumpable form, in which at least one storage tank is cleaned, sterilized, filled with sterile gas, filled with the product to be stored under aseptic conditions and at least under aseptic conditions is partially emptied, characterized in that all mass flows that are supplied to each storage tank and the stored product that is removed from each storage tank are passed through at least one mobile device, which on the one hand has stationary supply and disposal lines and on the other hand has at least one storage tank is detachably connected, and that the at least one mobile device means for measuring, controlling and regulating the flow rate, the pressure and for controlling the temperature as well as means for sterilizing the gaseous masses flowing through it a points out. 2. The method according to claim 1, characterized in that the stored product mixes under aseptic conditions or is homogenized by removing it from at least one storage tank, guiding it through the at least one mobile device and pumping it back into at least one storage tank. 3. The method according to claim 1 or 2, characterized in that the stored product is mixed and mixed under aseptic conditions with at least one other sterile product by the first product to be stored flowing through the at least one mobile device either during the filling of the at least one Storage tanks or during the mixing, homogenizing or pumping the first product within the mobile device, the at least one other sterile product is metered in under aseptic conditions. 4. The method according to any one of claims 1 to 3, characterized in that the filling and at least partially emptying of the at least one storage tank and the mixing, homogenizing, pumping and metering of the product (s) to be stored (s) are carried out under a sterilized protective gas atmosphere. 5. The method according to any one of claims 1 to 4, characterized in that the at least one storage tank to be supplied or removed, preserved product by a first mobile device, gaseous substances such as steam, inert gas, sterilized compressed air by a second mobile device and liquid cleaning and sterilizing agents as well as water are led through a third mobile device. 6. The method according to any one of claims 1 to 5, characterized in that the cleaning, sterilizing, filling with inert gas, filling and at least partially emptying the at least one storage tank, mixing, homogenizing, pumping over and metering in the product (s) to be stored ( s) and the maintenance of a sterile protective gas atmosphere computer-controlled semi or fully automatic and that the means contained in the at least one mobile device for measurement, control and regulation and for sterilization are also computer-controlled. 7. The method according to claim 6, characterized in that all computer-controlled processes are recorded digitally and / or analogously and the process data obtained in the process are stored electronically. 8. Device for generating and maintaining aseptic conditions in a tank system for the storage of food in preserved, pumpable form, in particular for performing the method according to one of claims 1 to 7, with at least one storage tank (1 ... 80) and stationary Installed supply and disposal lines (105) for the supply and discharge of stored or stored product and for the supply of steam, inert gas, compressed air, water and possibly liquid cleaning and sterilizing agents, characterized by at least one mobile device (W₁; W₂ ; W₃), on the one hand with the stationary supply and disposal lines (105) and on the other hand with at least one storage tank (1 ... 80) is detachably connected and the means for measuring, controlling and regulating the flow rate, the pressure and for checking the Temperature and means for sterilizing the ga flowing through them has s-shaped masses. 9. Device according to claim 8, characterized in that the mobile device (W₁; W₂; W₃) is movable. 10. Device according to claim 8 or 9, characterized in that the releasable connections are hose connections or pipes (108, 109; 118, 119; 128, 129, 129 '; 130, 131; 138, 139). 11. Device according to one of claims 8 to 10, characterized in that the fixed supply and disposal lines (105) have a plurality of connection points (107, 107a) for the at least one mobile device (W₁; W₂; W₃). 12. The device according to claim 11, characterized in that the tank system is a tank farm (100) and that the fixed supply and disposal lines (105) as ring lines which enclose the tank farm (100), or as spur lines. 13. The device according to claim 12, characterized in that it has only a single stationary ring line (105) with branch lines for the supply of steam, inert gas and compressed air. 14. Device according to claim 12 or 13, characterized in that the individual storage tanks (1 ... 80) of the tank farm (100) are arranged in groups such that each storage tank for the at least one mobile device (W₁; W₂; W₃) is freely accessible.

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