Method and device for filling with a filling product

Abstract

A method for filling with a filling product, for example for filling with a beverage in a beverage filling plant by the free jet method, includes supplying a flow of filling product through a filling product supply line by opening a filling valve disposed in the filling product supply line and opening an associated regulating valve for regulating a volume flow, and closing the regulating valve and the filling valve in order to end the flow of filling product at the end of filling. The closing of the regulating valve and the filling valve are synchronized. A corresponding device is also described.

Claims

1. A method for filling with a filling product, comprising: supplying a flow of the filling product through a filling product supply line by opening a filling valve disposed in the filling product supply line and opening a regulating valve configured to regulate a volume flow of the filling product; closing the regulating valve and the filling valve to end the flow of filling product at an end of filling, wherein the closing of the regulating valve and the filling valve are synchronized such that the regulating valve and the filling valve reach a closed position at the same time; and controlling the regulating valve and the filling valve with a time delay equal to a time offset.

2. The method of claim 1, further comprising providing a plurality of pairs of the regulating valve and the filling valve, and determining the time offset for each pair of the plurality of pairs.

3. The method of claim 1, wherein the closing of the regulating valve is initiated by a first control command and the closing of the filling valve is initiated by a second control command, and the second control command is initiated with a time delay from the first control command equal to the time offset.

4. The method of claim 3, further comprising determining the time offset from a difference between a closing time of the regulating valve and a closing time of the filling valve.

5. The method of claim 4, further comprising determining the time offset based on a flow measurement in the filling product supply line and determining the closing time of the filling valve using the flow measurement.

6. The method of claim 5, wherein the flow measurement comprises a change over time in a flow in the filling product supply line.

7. The method of claim 6, wherein the closing time of the filling valve is determined with respect to a minimum in the change over time in the flow and subsequent to an initiation of the second control command.

8. The method of claim 7, wherein the closing time of the filling valve is defined as a length of time between the initiation of the second control command and a time point at which the minimum occurs.

9. The method of claim 1, further comprising switching the regulating valve between at least two different volume flows for regulating the volume flow.

10. The method of claim 9, wherein the switching is stepless and adjusts the volume flow proportionally.

11. A device for filling with a filling product, comprising: a filling valve disposed at an end of a filling product supply line and configured to open and close the filling product supply line; a regulating valve disposed upstream of the filling valve and configured to regulate a volume flow of the filling product to the filling valve; and a control system configured: to close the regulating valve and the filling valve in a synchronized manner such that the regulating valve and the filling valve reach a closed position at the same time, and to actuate the regulating valve and the filling valve with a time delay equal to a time offset.

12. The device of claim 11, wherein the control system is further configured to issue a first control command to close the regulating valve and, with a time delay from the first control command equal to the time offset, to issue a second control command to close the filling valve.

13. The device of claim 12, wherein the control system is further configured to determine the time offset, and the time offset is determined from a difference between a closing time of the regulating valve and a closing time of the filling valve.

14. The device of claim 13, further comprising a flow meter associated with the filling valve and the regulating valve, wherein the control system is further configured to determine the time offset based on a flow measurement, and the closing time of the filling valve is determined using the flow measurement.

15. The device of claim 14, wherein the flow measurement comprises a change over time in a flow in the filling product supply line.

16. The device of claim 15, wherein the control system is further configured to determine the closing time of the filling valve with respect to a minimum in the change over time in the flow subsequent to initiation of the second control command, and the closing time of the filling valve is defined as a length of time between the initiation of the second control command and a point in time at which the minimum occurs.

17. The device of claim 11, wherein the regulating valve is configured to switch between at least two different volume flows for regulating the volume flow.

18. The device of claim 11, wherein the regulating valve comprises a proportional valve.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) Further embodiments and aspects of the present invention are more fully explained by the description below of the figures.

(2) FIG. 1 is a schematic side view of a device for filling with a filling product;

(3) FIG. 2 is a schematic plan view of the device from FIG. 1;

(4) FIG. 3 is a schematic switching diagram of a portion of a method for controlling the device from FIGS. 1 and 2;

(5) FIG. 4 is a schematic graphical representation of a flow over time; and

(6) FIG. 5 is a schematic graphical representation of the flow from FIG. 4 and its derivative over time.

DETAILED DESCRIPTION

(7) Examples of embodiments are described below with the aid of the figures. In the figures, elements which are identical or similar, or have identical effects, are designated with identical reference signs, and repeated description of these elements is in part dispensed with in order to avoid redundancy.

(8) FIG. 1 shows a schematic side view of a device 1 for filling with a filling product. The device 1 shown here can be used in particular for filling with a beverage in a beverage filling plant by the free jet method. The device 1 has a filling valve 3, disposed at the end of a filling product supply line 5, for opening and closing the filling product supply line 5, and a regulating valve 2 upstream of the filling valve 3 for regulating a volume flow of the filling product to the filling valve 3. In addition, a flow meter 4 is provided on the filling product supply line 5 for determining a flow rate or volume flow of filling product through the filling product supply line 5.

(9) In the example embodiment that is shown, the filling valve 3 is in the form of a pneumatically operated filling valve 3. To drive the pneumatically operated filling valve 3, tubing 6 is provided, by means of which pneumatic air can be supplied to the filling valve 3, in order to achieve a switching of the filling valve 3.

(10) The flow meter 4 is disposed upstream of the regulating valve 2. In other words, the regulating valve 2 is disposed between the flow meter 4 and the filling valve 3.

(11) At the end of the filling product supply line 5, i.e. the filling valve 3, a filling product outlet 10 is provided, from which a free jet of the filling product that is to be filled can discharge.

(12) The filling valve 3 and its associated regulating valve 2 together form a pair 7 including filling valve 3 and regulating valve 2. Each pair 7 can have its own flow meter 4 associated with it.

(13) In the example embodiment that is shown, the regulating valve 2 is designed such that it can switch steplessly. The regulating valve 2 is here designed as a proportional valve.

(14) In an alternative embodiment, the regulating valve 2 for regulating the volume flow can only switch between at least two different volume flows. For example, the regulating valve 2 can switch between a higher and a lower volume flow, or between a volume flow and no volume flow. In other words, the regulating valve 2 can also be designed as a simple switching valve.

(15) Generally, however, the regulating valve 2 for regulating the volume flow switches between more than two different volume flows.

(16) FIG. 2 shows a schematic overall plan view of a filler carousel of the device 1 from FIG. 1. On the periphery of the filler carousel are disposed a plurality of filling valve 3 and regulating valve 2 pairs 7, such as shown in FIG. 1, in order in this manner to produce a continual stream of filled containers.

(17) The device 1 further has a control system 8, which is in communication via connecting elements 9 with each individual filling valve 3 and regulating valve 2 pair 7. The control system 8 is configured to close the regulating valve 2 and the filling valve 3 of each pair 7, in each case in a synchronized manner.

(18) In the following part of this description, a method for filling with a filling product is described with reference to the device according to FIGS. 1 and 2. The method described here can be used in particular for filling with a beverage in a beverage filling plant by the free jet method. The method is here illustrated by means of FIGS. 3 to 5.

(19) FIG. 3 is a schematically shown switching diagram of a portion of the method for controlling the device 1 from FIGS. 1 and 2. FIG. 3 shows a regulating valve lift curve 12, a first control signal 13 for setting the lift 12 of the regulating valve 2, a valve cone lift curve 14 of a valve cone of the filling valve 3, and a second control signal 16 for setting the switching of the valve cone of the filling valve 3, over time.

(20) The filling valve 3 is generally embodied in the form of a simple switching valve, which can be designed for example as a seat valve. The filling valve 3 is displaced by means of a suitable actuator, for example a pneumatic actuator, from a fully closed position to a fully open position, and vice versa. Intermediate positions are, however, not possible.

(21) The regulating valve 2 is typically a proportional valve, which can be positioned in a controlled manner by means of a suitable control system. In other words, the control system can specify a particular lift position of the proportional valve, which then adopts this lift position in a defined and reliable manner. A proportional valve can for example have a stepper motor as actuator, in order to enable precise and reproducible controlled adoption of a desired lift position.

(22) Reference sign 120 indicates an open position of the regulating valve 2. In the open position 120 of the regulating valve 2, a maximum possible volume flow of the filling product that is to be filled can flow in the direction of the filling valve 3. In the closed position, which is indicated by the reference sign 122, the volume flow to the filling valve 3 is shut off. Reference sign 130 indicates an “open” signal setting specified by the control system 8, by means of which a specified lift of the regulating valve 2 can be regulated or set, and the reference sign 132 indicates a “closed” signal setting of the first control signal 13.

(23) Thus in the regulating valve 2, the controlled adoption of intermediate positions between the open position 120 and the closed position 122 is also possible. The position of the regulating valve between the open position 120 and the closed position 122 accordingly follows the ramp function of the first control signal 13. The indicated ramp function of the position and the ramp function of the control signal 13 are synchronous.

(24) As can be seen from FIG. 3, the control signal 13 is initiated by the control system 8 at a point in time T1, and effects a closing of the regulating valve 2. Due to this the regulating valve 2 progressively moves along the ramp function from the open position 120 to the closed position 122, which it reaches at time point T3. The regulating valve 2 thus has a closing time of tR, which corresponds to the length of time between time point T1 and time point T3. This closing time depends on the control system, and cannot be accelerated without limit due to the design of the regulating valve 2. In other words, the closing time is known to the control system.

(25) An open position of the filling valve 3 is also shown, indicated by reference sign 140. In the open position 140, the valve cone of the filling valve 3 is in a lifted position, so that the flow cross-section in the filling valve 3 is at a maximum. In the closed position indicated by the reference sign 142, the volume flow is shut off by the filling valve 3. Reference sign 160 indicates an “open” signal setting specified by the control system 8, and reference sign 162 indicates a “closed” signal setting of the second control signal 16. The filling valve 3 can adopt only the open or the closed position; intermediate positions are not possible due to the structure of the filling valve 3.

(26) If, as indicated by reference sign 16′, the second control signal is initiated simultaneously with the first control signal 13, the valve cone of the filling valve 3 traverses the curve indicated by the reference sign 14′ to reach the closed position 142. To reach the closed position 142 from the open position 140, the filling valve requires the closing time tF. Because the closing time tF of the filling valve 3 is shorter than the closing time tR of the regulating valve 2, the filling valve 3 reaches the closed position 142 while the regulating valve 2 is not yet closed. Due to this, pressure surges in the filling product supply line 5, induced by the closing of the filling valve 3, can occur, leading to oscillations of the filling product in the filling product supply line 5, which can be incorrectly interpreted by the flow meter 4 as additional flow.

(27) These pressure surges can be prevented if, as indicated by the reference sign 16″, the second control signal is initiated at the time point T3, after the regulating valve 2 has reached the closed position 122. Accordingly, only then does the filling valve 3 begin to move to the closed position 142, as indicated by the reference sign 14″. As a result, however, because at this time the filling valve 3 is open and the regulating valve 2 is closed and can provide no counter pressure of filling product, air from the surroundings can enter the filling product supply line 5.

(28) In order to remedy this behavior, the regulating valve 2 and the filling valve 3 are closed simultaneously. Accordingly, in the present example embodiment the filling valve 3 and the regulating valve 2 reach their closed positions, 122 and 142 respectively, at substantially the same time point T3. To achieve this, the valve cone of the filling valve 3 must traverse the curve that is indicated by means of the reference sign 14. The control signal 16 is consequently initiated at the time point indicated here by the reference sign T2, which is in advance of the time point T3 by a period equal to the closing time tF. In other words, the regulating valve 2 and the filling valve 3 are controlled to operate with a time offset tV, wherein the closing of the regulating valve 2 is initiated by the first control command 13 at time point T1, and the closing of the filling valve 3 is initiated by the second control command 16 at time point T2, and wherein the second control command 16 is initiated after a time delay equal to the time offset tV relative to the first control command 13.

(29) In the present case, the filling valve 3 is switched by a control system between the open position 140 and the closed position 142. The speed, and consequently the closing time tF, is therefore not controlled by the control system. In addition, the closing times of the individual pairs 7 of the device 1 differ.

(30) In order to be able to provide synchronized closing in accordance with reference signs 12 and 14 of each pair 7, the time offset tV is determined for each pair. In the present case, the time offset tV is determined from the difference between the closing time tR of the regulating valve 2 and the closing time tF of the filling valve 3. To achieve this, the closing time tF of the filling valve 3 is determined using the flow measurement.

(31) For this purpose, the control system 8 determines a change over time in the flow through the filling product supply line 5 as measured by the flow meter 4. To do this, the flow is determined during a closing process of the filling valve 3 that takes place prior to the actual filling with the filling product in normal operation, in which containers that are to be filled are filled with filling product.

(32) FIG. 4 shows schematically and by way of example a graphical representation of the measured flow 18 in ml/s of the filling product, against time in seconds, for one of the filling valves 3 of the device 1, as determined by the control system 8. Over the entire measuring period shown, the regulating valve 2 is maintained in a predetermined open switching position.

(33) Reference sign 16 again indicates the second control signal, which controls the filling valve 3. In the initial portion of the measuring period that is shown, the filling valve 3 is maintained in the open position, as indicated with reference sign 160. The flow 18 corresponds here to the flow in a filling phase 180. At the time point TS, the second control command 16 for switching the filling valve 3 to the closed position 162 is issued. As is immediately evident in FIG. 4, the reaction, in the sense of a change in the flow 18, is time-delayed, by approximately 0.4 seconds in this exemplary embodiment. This is referred to as the closing phase, indicated here by the reference sign 182. This time lag is due to the intrinsic inertia of the actuator of the filling valve 3 and of the media that are used for filling.

(34) Following the closing phase 182, a decreasing, oscillating volume flow takes place, which is substantially produced due to the oscillations in the filling product created by the closing of the filling valve 3, and is interpreted by the flow meter 4 as flow 18. Thus the transition 186 from the closing phase 182 to the oscillation phase 184 represents the time point TG at which the closed position is reached.

(35) FIG. 5 shows schematically the graphical representation of the flow 18 from FIG. 4 and its derivative 20 over time (as calculated in the control system 8). As is immediately evident from FIG. 5, just before the closing time point TG is reached, a clear, characteristic minimum 22 of the derivative 20 arises. This clear minimum 22 of the derivative 20 is recorded by the control system 8 and designated by the control system 8 as time point TM, the point in time at which the minimum 22 occurs.

(36) The closing time tF of the filling valve 3, which the filling valve 3 requires after the initiation of the control command 16 in order to reach the closed position, is now determined with respect to this minimum 22 of the time derivative 20 of the flow 18 after the initiation of the second control command 16. The closing time tF is thereby defined as the length of time from the initiation of the second control command 16, at the time point TS, to the time point TM at which the first minimum 22 of the derivative of the flow 18 occurs.

(37) Consequently, the determined and defined closing time tF is an approximation to the actual closing time, which is equal to the interval between the time points TS and TG.

(38) The time offset tV, by which the initiation of the second control command 16 is delayed with respect to the first control command 13, is determined by the control system 8 from the difference between the closing time tR of the regulating valve 2, and the closing time tF of the filling valve 3 as determined and defined by the control system 8, i.e. as tV=tR−tF.

(39) In order to determine the closing time tF of every filling valve 3 in the device 1, i.e. the time offset tV of every filling valve 3 and regulating valve 2 pair 7 in the device 1, the above-mentioned method is carried out for each individual filling valve 3 and regulating valve 2 pair 7 of the plurality of pairs 7 that are provided. In order to reduce the time required for this as far as possible, the determination by the control system 8 can be carried out at least in part in parallel. This determination can also be made for each filling product, with its individual viscosity and temperature.

(40) To the extent applicable, all features described in the individual example embodiments can be combined with each other and/or exchanged, without departing from the field of the invention.