Patent Application
20190010039
This invention relates to filling systems, and in particular, filling of beverage containers.
In a typical filling system, filling material fills a filling-material tank up to some level. This level varies over time as containers are filled and new filling material is added. The hydrostatic pressure, or filling pressure, is thus constantly changing.
The flow velocity at which the filling material flows into is determined at least in part by the filling pressure, and hence by the filling-material level in the tank. Thus, the flow velocity is also constantly changing.
In pressure filling systems, a container is sealed against a filling element. In such filling systems, a throttle valve adjusts the flow velocity. This throttle valve reduces the flow velocity to some value that is below the maximum value that could be attained given the current filling-material level. However, as the filling-material level is constantly changing, the pressure and hence flow velocity is constantly changing.
During pressure filling, it is fill a container with an inert gas at some relatively high preloading pressure. A difficulty that arises is that the preloading pressure and the filling pressure are independent of each other. This means that the preloading pressure must very accurately track the filling pressure so as to maintain a desired flow velocity. This makes it difficult to control flow velocity and volumetric flow rate.
It is an object of the invention to provide a method and apparatus for filling containers in which the filling speed is independent of the difference between the level of the filling material surface in a filling material tank and the level of the filling-material delivery opening at the filling point, and in particular also independent of pressure in a filling-material feed.
In the embodiments described herein, a control circuit controls the filling speed, i.e. the flow velocity at which the filling material flows to the container during filling. The pressure of the filling material in the product feed or product supply line, or a pressure difference between the pressure of the filling material in the product feed or product supply line and the pressure in the container, i.e. the filling pressure or preloading pressure, has essentially no influence on the control function. The pressure of the filling material in the product feed or product supply line is reduced to a filling pressure in the container, which is independent of the pressure and/or which is freely selectable and so which can be optimally selected preferably depending on the particular filling method and/or depending on the nature of the filling material and/or containers. The height difference is thus irrelevant or essentially irrelevant for the filling speed.
The control circuit comprises a volumetric-flow-rate control element through which filling material flows towards at least one filling point. This flow can be continuous or incremental. The volumetric-flow-rate control element facilitates regulating the volumetric flow rate. An electric or electronic governor can thus modify the volumetric flow rate of the filling material, i.e. the quantity of filling material flowing through the volumetric-flow-rate control element per unit of time.
The control circuit also comprises a sensor device to detect the volumetric flow rate of the filling material that is actually being fed to the filling point and to transmit, to the governor, a corresponding sensor signal as a measured value of the filling speed. The setting of the volumetric-flow-rate control element and hence the regulating of the volumetric flow rate are then effected by way of processing, for example by comparing the particular measured value with at least one target value of the filling speed. The measured value, i.e. the actual flow velocity of the filling material, can be calculated from the data supplied by the sensor device. Alternatively, the data supplied by the sensor device already indicates the velocity of the filling material, i.e. the measured value.
The target value preferably takes account of the nature of the particular filling material one or more factors singly or in combination. These factors include the type of container to be filled, the container's capacity, its size, and its shape. These factors also include the type of filling process. Examples of such types of filling processes include pressure-filling, pressureless filling, open-jet filling, filling methods that use long-tube filling systems, and filling methods in which filling material is introduced into the container as a flow film over the container's inner wall. Additional factors that can be taken into account include product-specific factors. The target value is therefore a product-specific, container-specific, and/or method-specific profile.
As used herein, a “target value” does not necessarily mean a single number. A “target value” can mean a time-varying function in which different flow rates occur at different times. This will also be referred to as a “profile” or “target profile,” a “time characteristic,” or a “time profile.” For example, it may be useful to have a slow flow rate at first followed by a faster flow rate later.
The desired or required filling speed can be maintained with great precision by regulating the flow using the control circuit. In particular, a significant improvement in the number of containers filled per unit of time can also be achieved by taking account of the nature of the filling material, the containers, and/or of the filling method. Through dynamic regulation as described herein, it is possible to compensate in real time for any changes of pressure, either in the filling material and/or in the preloading gas. As a result, these changes will not significantly affect filling speed. Instead, the control circuit regulates flow to compensate for these changes.
In the apparatus described herein, the flow velocity of the filling material flowing to the container, and hence the filling speed, results from the pressure difference between the pressure of the supplied filling material and the pressure inside the container.
Examples of a volumetric-flow-rate control element include a controllable throttle valve or a flow control valve. Examples of a sensor device that detects the volumetric flow rate include a flow meter through which the filling material flows. Examples of flow meters include a magnetic-inductive flow meter (MID) and a mass flow meter.
One advantage of the invention is that, with the filling system, despite it exactly maintaining a specified or desired filling speed, a filling material tank and in particular a partly filled filling-material tank can be dispensed with altogether, it being instead possible to feed the filling material under pressure to the individual filling points, or to the filling devices or filling blocks which form these filling points, through a common product supply line or a common product supply channel without the presence of a gas volume or gas buffer in this supply line or supply channel. Among other advantages, the fact that the invention obviates the need for a filling-material tank results in a design simplification and cost saving for the filling system, and in particular eliminates the risk of the filling material being contaminated by bacteria, especially on an exposed filling-material surface.
To enable regulating with a sufficiently wide regulating range, the pressure of the supplied filling material is preferably set so that it lies above the filling pressure, for example 0.5-3.0 bar above the filling pressure, at which the filling material is delivered into the container at the particular filling point. The preloading pressure or filling pressure of a preloading gas that is used when pressure-filling the containers is less than the pressure of the supplied filling material.
As pressure fluctuations are compensated by the regulating function and so basically do not affect the filling speed, there is no need for pressure sensors for monitoring and/or regulating the filling pressure and/or preloading pressure, in particular, at the filling devices or filling blocks within the control circuit that form the individual filling points.
In a preferred embodiment of the filling system, a liquid valve, which is configured for example as an open/close valve and which opens at the start of the filling phase and closes at the end of the filling phase, i.e. after the desired filling material height or filling material quantity in the container is attained, namely for example in response to a signal from a probe that reaches into the container during filling and/or from a weighing device that detects the weight of the containers and/or from a flow meter that in this case for example is the flow meter of the control circuit as well, is located in the direction of flow of the filling material upstream of the mouth or of at least one filling-material delivery opening of each filling point. To start the filling phase the liquid valve associated with the particular filling point is now opened and simultaneously or with a slight delay, for example with a delay of 25-80 milliseconds or with a delay of 25-50 milliseconds, the volumetric-flow-rate control element arranged upstream of the liquid valve when viewed in the direction of flow of the filling material is also opened if before the start of the filling phase it was in a state blocking the filling material. However it is also possible to use the respective liquid valve as a volumetric-flow-rate control element and for this purpose to configure it as a flow control valve that again enables the volumetric flow rate to be regulated continuously or incrementally.
The control circuit or the elements forming it are for example provided discretely for each filling point or in common for a plurality of filling points, and so form filling devices or filling blocks, e.g. having additional controllable gas-paths that are also provided discretely for each filling point or in common for a plurality of filling points. These can then be mounted and/or exchanged as fully functioning assemblies on the filling system, e.g. on a rotating rotor. An economical and compact design can be achieved especially where these filling devices are configured as multiple filling devices, i.e. as filling devices each having at least two filling points per multiple filling device and in which the elements of the control circuit are at least in part used in common for all filling points of a multiple filling device.
As used herein, the term “containers” includes cans and bottles made from metal, glass and/or plastic, and other packages suitable for filling liquid or viscous products.
As used herein, the expression “container located in sealed position against the filling point” means that the particular container to be filled lies with its container mouth pressed tightly against the filling point or against a local seal surrounding at least one delivery opening of the filling point.
As used herein, “open-jet filling” is understood to be a method in which the filling material flows to the container to be filled in a free stream with the container either being pressed with its mouth against the filling point separated from the filling point by a gap across which it flows.
As used herein, the expressions “essentially”, “in essence” or “around” mean variations from the respective exact value by ±10%, preferably by ±5% and/or variations in the form of changes insignificant for the function.
Further embodiments, advantages and possible applications of the invention arise out of the following description of embodiments and out of the figures. All of the described and/or pictorially represented attributes whether alone or in any desired combination are fundamentally the subject matter of the invention independently of their synopsis in the claims or a retroactive application thereof. The content of the claims is also made an integral part of the description.
The invention is described in greater detail below by reference to
Each filling point 4 has a product channel 6 that extends between a supply line 7 and the filling point's delivery opening. The supply line 7 is common to and supplies filling material to all the filling blocks 3. In the illustrated embodiment, the supply line 7 extends between the delivery opening and the filling tube 5.
A regulating valve 8 and a flow meter 9, both of which lie along the product channel 6, cooperate to regulate the volumetric flow of filling material through the product channel 6 either continuously or incrementally. In doing so, the flow meter 9 detects the quantity of filling material flowing through the channel 6 per unit time and supplies a corresponding electrical signal to an electronic controller or governor 18. In response, the governor 18 regulates the flow through the regulating valve 8.
A liquid valve 10 downstream of the flow meter 9 functions as an on/off valve that permits delivery of filling material when open and blocks its delivery when closed.
The regulating valve 8 thus functions as a controlled or regulated throttle that is part of a control circuit. For a given volumetric flow-rate of the filling material, a pressure difference is present at the regulating valve 8 between the pressure in the container 2 and the pressure upstream, for example in the supply line 7 or any other element of the filling system that feeds or supplies the filling material.
The first filling-system 1 includes first, second, and third controlled gas-paths 11, 12, 13 that, when the container 2 is located in sealed position against the filling point 4, are also connected to the container's interior and are also associated with each filling device 3 or each filling point 4.
A first control-valve 11.1 connects the first gas-path 11 to a first annular-channel 14. A second control-valve 12.1 connects the second gas-path 12 to a second annular-channel 15. In addition, the second gas-path 12 includes a throttle valve 17 along it. A third control-valve 13.1 connects the third gas-path 13 to a third annular-channel 16. The first, second, and third annular-channels 14, 15, 16 are provided for all the filling devices 3 and the filling points 4 in common.
A pressure regulator 7.1 connects the supply line 7 to a source of filling material. The source supplies the filling material under pressure so that a constant or essentially constant filling pressure is present in the supply line 7 during the filling operation.
During the filling operation, a vacuum pump 14.1 maintains the first annular-channel 14 at a vacuum or negative pressure. The second annular-channel 15 vents to the environment, as a result of which it carries ambient or atmospheric pressure. The third annular-channel 16 carries a preloading gas maintained at a pressure by a pressure regulator 16.1 that connects to a gas source. The preloading gas is typically an inert gas such as carbon dioxide at a preloading pressure that is slightly below the filling pressure.
The filling-material source, the gas source, and the vacuum pump are outside the rotor and do not rotate with it. The corresponding connections to the first, second, and third annular-channels 14, 15, 16 therefore extend through a rotary joint 21 between the rotor and a machine frame.
At each filling point 4, the first filling-system 1 makes possible a filling process that comprises the typical process steps described below. During the process, the container 2 that is being filled is sealed against the filling point 4. Unless otherwise indicated as open, all valves are closed.
A process controller controls the opening and closing of the first, second, and third control-valves 11.1, 12.1, 13.1 during a filling process.
The filling process begins with opening the first control-valve 11.1 to connect the container's interior to the first annular-channel 15 via the first gas-path. Since the first annular-channel 14 carries a vacuum, this evacuates the container 2.
The next step is to open the third control-valve 13.1 to connect the container's interior with the third annular-channel 16. This preloads the container's interior with the preloading gas and applies the preloading pressure to the container's interior. The steps of evacuating and purging the container can be carried out multiple times.
With the third control-valve 13.1 remaining open, the next step is to open the liquid valve 10 and, at the same time or shortly thereafter, to open the regulating valve 8. As a result of opening the liquid valve 10, the preloading pressure in the container 2 becomes present in the product line 6. This begins the filling process. During filling, the governor 18 regulates the flow through the regulating valve 8 so that it matches a pre-stored profile that is specific to the liquid filling material, the container, and the filling method. The profile is stored, for example, in the governor 18 or in a process control computer of the first filling-system 1 that interacts with the governor 18. As filling material enters the container, it displaces preloading gas from the container's interior through the still-open third control-valve 13.1. The displaced preloading gas thus returns to the third annular-channel 16.
When the flow meter 9 indicates that the required amount of filling material has entered the container 2, it sends a signal to the governor 18 to halt filling.
In a subsequent calming and relieving step, the liquid valve 10 and/or the third control-valve 13.1 remain closed so as to calm the filling material that has flowed to the container 2. After the end of a given calming period, the second control-valve 12.1 opens. This relieves pressure in the container 2 so that it matches that in the second annular-channel 15.
A common regulating valve 8 lies along the main section 6.1 between the branch sections 6.2 and the supply line 7. The regulating valve 8 is again part of a control circuit which comprises two flow meters 9, one for each branch section 6.2, as well as a governor 18, which controls the regulating valve 8 as a function of the target value of the filling speed and an averaged measured value calculated from the output signals of the two flow meters 9. The governor 18 controls the regulating valve 8 in the same way to achieve a target filling profile.
The process steps for using the second filling-system 1a are the same as those discussed in connection with the first filling-system 1. These process steps are carried out simultaneously for both the filling points 4.
Like the first filling-system 1, the second filling-system 1a is also configured for volumetric filling of containers 2, i.e. the liquid valves 10 are each closed as a function of the signal from the flow meter 9 that is associated with the respective filling point 4.
In the third filling-system 1b, the liquid valves 10 of the two filling points 4 are both provided in the branch sections 6.2 of the product channel 6, while a common flow meter 9 for both filling points 4 and a common regulating valve 8 for both filling points 4 are provided in main section 6.1. Together with the flow meter 9 and the governor 18, the regulating valve 8 again forms part of a control circuit that regulates the rate at which filing material flows into containers 2. It does so by comparing a measured value supplied by the flow meter 9 with a target value of the filling speed and controlling the regulating valve 8 to so that the actual flow rate tracks a pre-determined filling speed characteristic or profile.
The third filling-system 1b uses the same process steps described for the first filling-system 1 by appropriate operation of the first, second, and third control-valves 11.1, 12.1, 13.1, which are again common to both filling points 4 of this dual filling element. Except for the final closing of the liquid valves 10, which is effected for both filling points 4 individually as a function of the signal from the filling height probe 19, the other process steps again take place simultaneously.
Thus the essential core of the above described filling systems 1,1a and 1b and/or of the methods performed with these systems lies in the fact that, during the filling process, a control circuit monitors and regulates the filling speed so that at any time during the filling phase the desired filling speed is exactly maintained even though the filling material is fed under pressure to the individual filling points 4 not from a partly-filled filling-material tank but from a supply line 7 or from a tank or annular channel that is completely filled with the filling material, and that the pressure in the supply line 7 is reduced to an independent and/or freely selectable filling pressure in the container 2.
Filling systems have so far been described for filling the containers 2 that during the filling process, and in particular during the filling phase as well, are sealed against the filling point 4. However the active regulation of filling speed is also suitable for pressureless filling of containers and for open jet filling in particular. The filling points 4 of such a filling system comprise the same configuration as has been described for the first, second, and third filling-systems 1, 1a, 1b. However, the first, second, and third controlled gas-paths 11, 12, 13 and their associated first, second, and third control-valves 11.1, 12.1, 13.1 are omitted, as these are not needed for open-jet filling.
It has also been assumed above that, with the first and second filling-systems 1, 1a which are configured for volumetric filling, the flow meters 9 that are part of the control circuit for regulating the filling speed also supply the signal for the final closing of the filling point 4 or liquid valve 10.
In an alternative embodiment, an additional sensor system detects the quantity of filling material flowing to the container 2 for deciding when to terminate the filling phase. Examples of an additional sensor system include an additional flow meter or other measurement system, such as a weighing system.
Some embodiments feature a throttle section 20, as shown in
When used in conjunction with open jet filling this can significantly reduce any ingress of micro-bubbles into the container to be filled when bottling carbonated drinks. The dosing of such bubbles and micro-bubble ingress into the already bottled filling material also makes it possible to significantly reduce the filling pressure towards atmospheric pressure.
Another advantage is also offered by the fact that it is possible to further reduce the weight of containers or bottles made from PET and so significantly reduce the cost of a filling plant or filling line and of any necessary cooling of the container base. Glass breakage is reduced when containers made from plastic are being filled. The consumption of preloading gas can also be reduced.
Pressure sensors with which the pressure is monitored and/or set and/or regulated to a target value are also preferably provided in the product channels 6 and/or in the product supply channel 7 and/or in the annular channels 14 and 16 and/or in the gas paths connected to these annular channels.
| Number | Date | Country | Kind |
|---|---|---|---|
| 102015111536.0 | Jul 2015 | EP | regional |
This application is the national stage under 35 USC 371 of international application PCT/EP2016/065741, filed on Jul. 4, 2016, which claims the benefit of the Jul. 16, 2015 priority date of German application DE 10-2015-111-536.0, the contents of which are herein incorporated by reference.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2016/065741 | 7/4/2016 | WO | 00 |
