Patent Publication Number: US-11639288-B2

Title: Apparatus and method for filling containers with liquid contents

Description:
RELATED APPLICATIONS 
     This is the national stage of PCT application PCT/EP2019/072929, filed on Aug. 28, 2019, which claims the benefit of the Sep. 11, 2018 priority date of German application DE 102018122062.6, the contents of which are incorporated herein by reference. 
     FIELD OF INVENTION 
     The invention relates to an apparatus for filling containers with a liquid or filling product and to a method for filling containers. 
     BACKGROUND 
     Container handling machines in the beverage industry are expected to process upwards of 10,000 containers per hour. Some machines have capacities of more than 50,000 containers per hour. Of particular importance are filling machines. 
     A known method of filling, sometimes called “lightning filling,” is to drive liquid under pressure into a container filled with steam with positive overpressure in the source of the product and negative pressure in the container. In this case, the steam condenses into water as a result of contact with the product. This makes determining the filling level imprecise. 
     Another known way to fill rapidly is a form-fill process. In such a process, one drives the product into a pre-form, thus bypassing the step of blow-molding the pre-form with gas. The volume of product that enters is measured by a flow meter. However, because of the high flow velocity, the measurement process is prone to inaccuracy. 
     SUMMARY 
     An object of the invention is to provide a device for filling containers with a liquid product that avoids the disadvantages of the prior art referred to heretofore, and with which the containers filled in particular by free-jet filling, lightning filling, or form-fill processes, the containers can be filled with the nominal or reference volumes required for them, and that therefore allows for reliable and precise measurement accuracy of the filled product in the containers. 
     According to a first aspect, the invention relates to a device for filling containers with liquid contents. Such a device includes at least one filling element for filling the container, a product feed-line for filling the container, at least one switching valve for switching the stream of contents to the at least one filling element, and at least one control valve, which is arranged upstream of the switching valve for controlling the stream of contents flowing through the switching valve. It is understood that the device according to the invention is a part of the system or, more precisely, is a part of a filling system. 
     The device according to the invention comprises at least one filling vessel arranged between the switching valve and the control valve and at least one volume-measuring device arranged between the switching valve and the control valve. In this situation the filling vessel provides a filling quantity of the product which has been pre-metered by means of the volume-measuring device per volume measurement for discharge to the filling element via the switching valve. In other words, the quantity filled into the container that is to be filled is already measured and provided separately or simply held in intermediate storage before the actual filling. This has the advantage that, while the container to be filled is being prepared, by evacuation, pre-stressing, closure, transfer for the filling, etc., an adequately long period of time is available for providing and measuring the filling contents. As a result, the pre-metered filling quantity from the filling vessel can be filled into the container with the nominal or reference volume conveyed to the container, and, in particular, advantageously at a very high speed. 
     In some embodiments, a first control circuit is assigned to the product-feed line. The first control circuit comprises a first pressure sensor for detecting the pressure in the product-feed line, at least one first regulating and control valve, and a first regulating and control unit. 
     To avoid confusion, it is noted that the term “circuit” is used in its older pre-electronic sense of indicating a loop or closed path. As such, the term “circuit” implies the existence of a closed control loop or feedback loop. However, the term “circuit” is not intended to be restricted to an electronic circuit in which the closed path is one traversed by charge. 
     In other embodiments, a distribution device, or distributor, is arranged downstream of the first regulating circuit. The distributor ultimately conveys the filling product to the at least one filling element. Accordingly, the filling speed, i.e. the flow speed, at which the filling product flows to the distribution device during the filling of the filling vessel, is regulated by making use of the first control circuit. 
     Preferably, the distribution device is configured as a filling product tank, which during the filling operation is partially filled with the liquid filling product, and specifically with the formation of a lower liquid space and an upper gas space, which is filled with a pre-stressing gas which is under filling pressure. The pre-stressing gas, which is preferably configured as CO2 gas, can be conveyed to the filling product tank by means, for example, of a feed line, not explained in any greater detail. 
     In other embodiments, the filling vessel is configured as a header vessel or a measuring and/or metering vessel, which, by means of the volume-measuring device, or volumeter, provides the pre-metered filling quantity per volume measurement to be discharged via the switching valve to the filling element. 
     Particularly advantageously, the volume-measuring device is arranged upstream of a header vessel and is configured as a flow-meter. As the flow-meter, use can be made for the invention of any flow measurement devices known from the prior art, such as, for example, volume flow-meters or mass flow-meters. Preferably, in this case a magnetic-inductive flow-meter (MIF) is configured as a volume measurement device, which undertakes the volume measurement for the pre-metering of the filling product for the at least one header vessel, i.e. determines the throughflow quantity of the filling product. 
     In other embodiments, assigned to the at least one header vessel is a second regulating circuit, which comprises at least one second pressure sensor for detecting the pressure in the at least one header vessel, at least one second regulating and control valve, and a second regulating and control unit. 
     For particular preference, a pressure regulating device, for the controlled and/or regulated conveying of a pre-stressing gas to the at least one header vessel, is assigned to the second regulating circuit. The second regulating circuit can therefore be configured, for example, as a pressure regulating circuit. 
     According to another advantageous embodiment variant of the device according to the invention, the device comprises a plurality of header vessels. In this situation, in each case, a corresponding number of regulating circuits are assigned to each header vessel, and, moreover, slide valves are provided between the switching valve and the control valve, by means of which the filling product flow into and out of the respective header vessels can be switched by means of the slide valves. 
     Particularly advantageously, the device according to the invention is configured as a filling machine of a circulating type, with a plurality of filling elements on a rotor which can be driven such as to rotate about a vertical machine axis, wherein the filling product for the filling elements is provided in the filling tank, likewise provided on the rotor and partially filled with the filling product, wherein, however, all other structural types of filling machines known from the prior art can likewise be used with the invention, without thereby departing from the concept of the invention. 
     According to another advantageous embodiment variant of the device according to the invention, the at least one measurement and/or metering vessel itself functions as a volume-measuring device. Particularly advantageously, for the filling of the at least one measurement and/or metering vessel, a piston-cylinder system is provided, which is driven by a controlled drive unit. In this situation, the drive unit is advantageously configured as a linear drive. With such measurement and/or metering vessels, the volume, i.e. the filling product quantity, is predetermined by the geometry of the piston-cylinder pair and the stroke travel of the piston in the cylinder. Accordingly, with such measurement and/or metering devices, the piston-cylinder pair serves both as a pump as well as a measuring device. 
     According to another advantageous embodiment variant of the device according to the invention, a cross-section of a product discharge line downstream of the at least one switching valve is greater than a cross-section of the product supply line, such that the filling product can thereby be discharged even more rapidly from the at least one filling vessel into the container. 
     According to another advantageous embodiment variant of the device according to the invention, the device is designed and configured in such a way that the supply of the filling product into the at least one filling vessel takes place at a first filling speed, measured as volume per time, and the discharge of the filling product from the at least one filling vessel, via the switching valve and filling element into the container, takes place at a second filling speed, measured as volume per time, wherein the second speed is greater than the first speed. Like the preceding embodiment variant, this embodiment variant also makes it possible, by imposing the second filling speed in relation to the first filling speed, to achieve a rapid discharge of the filling product from the at least one filling vessel into the container. The imposition of the speed is achieved, for example, by an imposition of pressure on the filling product in the product discharge line. Moreover, a combination of both embodiment variants is conceivable, namely a greater cross-section of the product discharge line as well as a second higher filling speed, such that a rapid filling, if not even a “lightning fast” filling of the container is possible. 
     According to a further aspect, the present invention also relates to a method for the filling of containers with a liquid filling product. In this situation, the filling product is conveyed via a product supply line to at least one switching valve, for switching the filling product stream to the at least one filling element, and at least one control valve, upstream of the switching valve, for controlling the filling product stream flowing through the switching valve, to at least one filling element for the filling of the container. The present invention is further characterized in that provision is made for a filling vessel arranged between the switching valve and the control valve, and for a volume-measuring device arranged between the switching valve and the control valve. By means of the at least one filling vessel, a pre-metered filling product quantity of the filling product is then supplied by means of the volume-measuring device, per volume measurement, for discharge via the switching valve to the filling element. 
     The core of the concept underlying the invention can essentially be seen in the fact that, by the pre-metering of the filling product quantity and by the providing of a pre-metered filling product quantity of the filling product in the at least one filling vessel, a reliable and precise measurement precision of the filling product filled into the containers can be achieved. Specifically, by this pre-metering by means of the at least one filling vessel, substantially more time is available for the measurement of the filling product, which is precisely what allows for these accuracies of measurement. The invention is therefore also particularly well-suited for devices and methods with which the filling product is filled rapidly into the containers, and in particular with which the filling product is accelerated during the filling to a maximum speed, as is the case with “lighting” filling or form-fill filling. Here too, by the pre-metering of the filling product quantity, the nominal or reference volume of the filling product conveyed to the containers can be precisely determined, and the filling at a substantially higher speed can be ensured. 
     The expression “essentially” or “approximately” in the meaning of the invention signifies deviations from the respective exact value by +/−10%, preferably by +/−5%, and/or deviations in the form of changes which are not of significance for the function. 
     Further embodiments, advantages, and possible applications of the invention are also derived from the following description of exemplary embodiments and from the Figures. In this situation, all the features described and/or represented in the Figures are in principle the object of the invention, individually or in any desired combination, regardless of their arrangement in the claims or reference to them. The contents of the claims are also made a constituent part of the description. As used herein, “regulating” refers to the use of a closed loop or feedback loop. A regulating system involves a measured variable, a manipulated variable, and a set point. In general, the regulating system attempts to minimize an error between the measured variable and the set point by varying the manipulated variable in a manner that depends on the observed error. Accordingly, the broadest reasonable interpretation of regulating and cognates thereof is not to be construed to cover any and all types of control that are possible. 
     Although some aspects have been described in connection with a device, it is understood that these aspects also represent a description of the corresponding method, such that a block element or a structural element of a device is also to be understood as a corresponding method step or as a feature of a method step. By analogy with this, aspects which have been described in connection with a method step or as a method step also represent a description of a corresponding block or detail or feature of a corresponding device. Some or all of the method steps can be carried out by a hardware apparatus (or with the use of a hardware apparatus), such as, for example, a microprocessor, a programmable computer, or an electronic circuit. With some exemplary embodiments, some or many of the most important method steps can be carried out by such an apparatus. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The method is described hereinafter in greater detail on the basis of the Figures relating to exemplary embodiments. These show: 
         FIG.  1    shows an embodiment of a device for the filling of containers with a liquid filling product; 
         FIG.  2    shows another embodiment of a device for filling containers. 
         FIG.  3    shows yet another embodiment of a device for filling containers. 
         FIG.  4    shows another embodiment of a device for filling containers. 
     
    
    
     Identical reference numbers are used in the Figures for elements of the invention which are the same or have the same effect. Moreover, for the sake of easier overview, only those reference numbers are represented in the individual Figures which are required for the description of the respective Figure. The invention is also represented in the Figures only in schematic views to explain the mode of operation. In particular, the representations in the Figures serve only to explain the underlying principle of the invention. 
     DETAILED DESCRIPTION 
       FIGS.  1 - 4    shows a device  1  for carrying out free-jet filling of containers  2  with a liquid filling-product  3 . 
     The device  1  comprises a filling-and-closing device  23  having a filling element  22  that fills the container  2  with liquid filling-product  3  that is fed from a product-feed line  4 . The device  1  also includes a switching valve  6  and a control valve  7  upstream of the switching valve  6 . The control valve  7  controls the stream of product  3  that flows towards the switching valve  22 . The switching valve  22  switches the stream of product  3  towards the filling-and-closing device  23 . Some embodiments include more than one filling element  22 , switching valve  6 , and control valve  7 . 
     The device  1  also includes at least one filling vessel  8  and, in some embodiments, two filling vessels  8 ,  9 . The filling vessels  8 ,  9  are arranged between the switching valve  6  and the control valve  7  along the path taken by the product  3 . The device  1  also includes a volumeter  5  between the switching valve  6  and the control valve  7 . Alternative embodiments include those with more than two filling vessels  8 ,  9  and those with more than one volumeter  5 . 
     The volumeter  5  pre-meters a quantity  10  of product  3 , which is held in the filling vessel  8 ,  9 . This volume  10  is to be discharged, via the switching valve  6 , to the filling element  22 . This pre-metering is able to take place while the container  2  is being prepared for filling, for example by evacuation, pre-stressing, while the container  2  is being transferred, or while the previously-filled container  2  is being closed. This provides ample time for pre-metering. As a result of pre-metering, it becomes possible for a precise volume of liquid to be filled from the filling vessel  8 ,  9  or the filling vessels  8 ,  9 . This is particularly useful for cases in which the container is to be filled rapidly. The invention is therefore also well-suited in particular for devices  1  and methods with which the filling product  3  must be filled rapidly for example, with lightning filling or form-fill filling. 
     To promote more rapid filling from the vessel  8 ,  9 , it is useful for to have a discharge line  20  having a cross-section that is greater than that of the feed line  4 . The discharge line  20  extends downstream of the switching valve  6 . 
     In some embodiments, product  3  travels through the feed line  4  at a first volume rate-of-flow V 1  and discharges into the filling element  22  at a second volume rate-of flow V 2  that exceeds the first. In some cases, the second flow rate V 2  is between about half a liter per second and two liters per second, or on the average at one liter per second or one and a half liters per second. The first flow rate V 1  can be less than one liter per second or even less than half a liter per second. This permits volume to be measured more precisely. 
     The embodiment shown in  FIG.  2    includes a header vessel  8  that supplies the quantity  10  of product  3 , which has been pre-metered by the volumeter  5 . In the embodiment shown, the volumeter  5  is a flow meter  5 , such as a magnetic-inductive flow meter. 
     The embodiment of  FIG.  2    also includes a first regulator RK 1  that includes a first pressure sensor  13 , a first regulating valve  11 , and a first controller  12 . The first pressure sensor  13  detects pressure in the feed line  4  and provides it to the first controller  12 , which thus carries out closed loop feedback control of the regulating valve  11 . 
     The embodiment of  FIG.  2    also includes a distributor  24  arranged downstream of the first regulator RK 1 . The distributor  24  conveys the filling product  3  towards the header vessel  8 . The first regulator RK 1  thus regulates the rate at which the product  3  flows to the distributor  24  during the filling of the header vessel  8 . 
     In  FIG.  3   , the distributor  24  comprises a tank  24 . During filling, the tank  24  is partially filled with the liquid filling product  3 . This results in a lower liquid space  24 . 1  and an upper gas space  24 . 2 . A pre-stressing gas, which is maintained at a filling pressure, fills the upper gas space  24 . 2 . The pre-stressing gas, which is preferably carbon dioxide, is conveyed to the tank  24  using a line that has been omitted for clarity. 
     The device  1  also includes a second regulator RK 2 . The second regulator RK 2  includes a second pressure sensor  18 , a second regulating valve  15 , and a second controller  17 . The second pressure sensor  18  detects pressure in the header vessel  8 . 
     In a preferred embodiment, the second regulator RK 2  includes a pressure regulating device  14  together with a second switching valve  16  for controlling or regulating the conveyance of a pre-stressing gas to the header vessel  8 . The second regulator RK 2  is therefore a pressure regulator. 
     The second regulator RK 2  regulates the pressure in the container  2  so that it remains below the pressure of the gas space  24 . 2 . This suppresses foaming due to any dissolved carbon dioxide in the product  3 . The second regulator RK 2  carries out such regulation during the pre-stressing phase, and at least before the beginning of the subsequent filling of the pre-metered filling product quantity  10  into the container  2 . 
       FIG.  3    shows a further embodiment of the device  1  that differs as a result of having not one but two filling vessels in the form of header vessels  8 . It is also conceivable, however, that other embodiments have more than two vessels  8 . 
     The embodiment shown in  FIG.  3    includes both the second regulator RK 2  and a third regulator RK 3  that together have regulating valves  15 ,  16 ,  25 ,  26 , pressure sensors  18 ,  28 , and controllers  17 ,  27 . Each regulator RK 2 , RK 3  is assigned to its own vessel  8 . 
     The embodiment shown also includes corresponding slide valves  19  between the switching valve  6  and the control valve  7  for switching the product stream into and out of the respective header vessels  8 . 
     The embodiment shown in  FIG.  3    is particularly useful for lightning filling and for form-fill processes because of the demand for high speed. Such methods aspire to fill a half liter container in about three hundred milliseconds. With such speeds expected, it is possible that the flow meter  5  will not be able to measure volume with enough precision even with the use of a header vessel  8 . However, having two header vessels  8  for each container  2  is to be filled enables the header vessels  8  to cooperate. As an example, while a container  2  is being filled with filling product  3  with a predefined filling product quantity  10  from one header vessel  8 , the other header vessel  8  can be filled with the desired filling product quantity  10 . Thus, the header vessels  8  alternate so that one can be filled while the other is being used for filling the container. 
     The embodiment shown in  FIG.  4    has a filling vessel that is configured as a measuring and/or metering vessel  9  that supplies the filling product quantity  10  of the filling product  3 , which has been pre-metered by the volumeter  5 , per volume measurement, for discharging via the switching valve  6  to the filling element  22 . 
     In this embodiment variant shown, the measuring and/or metering vessel  9  itself functions as a volumeter  5 . In this embodiments, a drive  21  drives a piston  9 . 2  of piston-cylinder system  9 . 1  through a cylinder  9 . 3  to fill the vessel  9 . Preferably, the drive is a linear drive  21  that controls the quantity  10  and the flow rate. In this embodiment, the geometry of the piston-cylinder system  9 . 1  and the piston&#39;s stroke controls the quantity  10 . 
     The invention has been described heretofore by way of exemplary embodiments. It is understood that numerous modifications and derivations are possible, without thereby departing from the inventive concept underlying the invention.