JP2014129143A - Filling machine, in particular, for filling container with pasteurized liquid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To purify, at a low cost, pressurized gas for filling a pasteurized liquid into a container.SOLUTION: A filling machine, in particular, for filling a container with a pasteurized liquid includes: a gas line 37; a liquid supply line 7 which is adjusted so as to be connected to a liquid tank 8; and at least one filling device 15 which is provided with an inlet communicating with the liquid supply line 7, a lower outlet, and a gas port communicating with the gas line 37. The filling machine further includes a differential pressure sensor 51 which is connected to the gas line 37 and the liquid supply line 7 to determine a feedback value defined by a pressure difference between the lines. The gas line 37 permanently communicates with a gas tank 41, which is separated from the liquid supply line 7 and connected to a pressurized gas source and an exhaust opening through valves 44 and 48, respectively, and the valves 44, 48 are controlled by an electronic control unit to adjust a pressure difference between the liquid supply line 7 and the gas line 37 to a set value according to the feedback value.

Description

  The present invention relates to a filling machine for filling containers with a particularly pasteurized liquid.

  As is generally known, a filling machine typically includes a filling station that is fed with an empty container and provides a container filled with liquid at its output.

  The filling station basically has a rotating conveyor that rotates around a vertical rotation axis and carries a plurality of filling devices, the plurality of filling devices being spaced radially from the rotation axis of the conveyor. Is done. More specifically, the conveyor arranges the mouth of the container under the respective filling device, and moves the container together with the respective filling device along an arc-shaped path around the rotation axis. A plurality of container supports are included.

  Each filling device has a filling head (filling) movable along a direction parallel to the axis of rotation of the conveyor to move from and to the filling chamber and the respective container mouth. head). Each filling device has a closed position to block liquid flow to the mouth of the respective container and an opening that allows the filling chamber to communicate with such mouth, thereby allowing liquid to flow into the container. It further includes a stopper that is movable within the filling chamber between positions.

  The filling machine further includes a supply system that connects the filling chamber to a main tank in which the liquid for filling the container is stored and pressurized. In some embodiments, particularly for pasteurized liquid, the supply system includes a supply line connecting the filling station to the main tank, a bottom in communication with the supply line, and a gas or carbon dioxide, A buffer tank having a top, which communicates with the line and pressurizes the liquid at the bottom, and is arranged along the supply line between the buffer tank and the filling station and without recirculation of the liquid to the main tank And a pump controlled to supply liquid from the bottom to the filling station.

  Before being filled with a liquid containing carbonic acid, each container has several preliminary steps, in particular a first evacuation step (in which air is drawn from the vessel using a vacuum system) and a flushing step. (In this, carbon dioxide is supplied into the container and mixed with the remaining air) and the second evacuation step (in which mixing of residual air and carbon dioxide is sucked using a vacuum system) And a pressurizing step (in which carbon dioxide is supplied into the container from the gas line described above to pressurize the container to a given pressure).

  After pressurization, the stopper is moved to the open position and the container is filled. In particular, the filling may include a fast first filling step followed by a slow second filling step. For the purpose of controlling the start and / or stop of the first and second filling steps, each filling device further comprises a sensing device (in particular a probe) for detecting the level of liquid inside the container.

  After filling the container with liquid, the carbon dioxide in the container neck is depressurized so that the pressure above the liquid level is equal to atmospheric pressure.

  During the filling process, carbon dioxide gradually flows out from each vessel towards the gas line and thus towards the top of the buffer tank. The pump, on the other hand, adjusts the pressure difference between the pressure of the pumped liquid and the pressure in the gas line in relation to the set point set according to the process and / or liquid type. Controlled by the control unit.

  The above types of filling machines are somewhat unsatisfactory, especially due to the cost and complexity of the supply system connecting the filling station to the main tank. In particular, the supply system described above requires the installation of relatively large buffer tanks and controlled pumps with corresponding valves and connections.

  Moreover, the gas used to pressurize the container prior to filling is not pure because it comes from the storage space, ie the top of the buffer tank where the gas is in contact with the liquid.

  The object of the present invention is to make it possible to overcome the above drawbacks in a direct and low-cost manner and to direct the liquid from the main tank's hydrostatic head to the filling station, in particular without compromising the overall control of the filling process. It is to provide a filling machine that allows a filling station to be connected directly to the main tank without a buffer tank for use as a pressure source for supply. In particular, the control of the filling process must be carried out promptly in response to changes in the hydrostatic head of the main tank.

  This object is achieved by a filling machine for filling containers with a particularly pasteurized liquid as defined in claim 1.

  Non-limiting embodiments of the present invention will now be described by way of example with reference to the accompanying drawings.

Figure 2 is a schematic cross-sectional view partially showing a filling machine for filling a container with a particularly pasteurized liquid according to the present invention. It is a perspective view which shows the detail of the machine of FIG.

  1 and 2, reference numeral 1 generally designates a machine (partially and schematically shown) for filling the container 2 with liquid.

  As shown in FIG. 2, each container 2 has, by way of example, a glass or plastic bottle and has a substantially vertical axis 3 bounded at the bottom by a bottom wall 4 substantially perpendicular to the axis 3. And has an upper neck 5 substantially coaxial with the shaft 3.

  Referring to FIG. 1, the filling machine 1 is equipped with a filling station or filling assembly 6 and a liquid supply line 7 (which is filled without any buffer tank or any pump between the liquid tank 8 and the filling station 6). Station 6 in communication with liquid tank 8).

  The liquid tank 8 contains the liquid to be filled in the container 2 and includes an upper part 9 connected to a pressurized gas source 10, in particular a carbon dioxide source for pressurizing the liquid. In particular, the liquid is defined by beer obtained using a pasteurization process. In general, the liquid tank 8 is not part of the machine 1 but is connected to the supply line 7 using a pipe joint (not shown). The supply line 7 may comprise a shut-off valve for optionally closing the liquid flow path towards the filling station 6.

  The filling station 6 has at least one support and filling unit 14 (which is a support 16, located below the filling device 15 and the device 15 and designed to support the bottom wall 4 of the respective container 2. Including). The unit 14 connects one of the device 15 and the support 16 to one of the device 15 and the support 16 in order to couple / separate the device 15 with the upper mouth of the container 2 received on the support 16. An actuator (not shown) is further included for moving along the vertical axis relative to the other.

  As shown in FIG. 2, the filling station 6 comprises a plurality of the above-described units 14 (which are conveyors 19 that form part of the filling machine 1 while the containers 2 are filled with the liquid supplied by the respective devices 15. (Partially shown) and transported along the path). The conveyor 19 is preferably mounted on the base structure so as to be continuously rotated about a substantially vertical axis 20 defined by a rotating conveyor. The conveyor 19 receives a series of empty containers 2 from an input wheel 21 (which is mounted to cooperate with the conveyor 19 at the transfer station 22 and to rotate about an axis parallel to the axis 20). . The conveyor 19 is connected to an output wheel 24 (which is mounted to cooperate with the conveyor 19 at the transfer station 25 and to rotate about an axis that is also parallel to the axis 20). To release. The rotation of the input wheel 21 and the output wheel 24 is continuous and is synchronized with the rotation of the rotary conveyor 19.

  Preferably, the units 14 are equally spaced from each other around the axis 20 and are equally spaced from the axis 20. Accordingly, the unit 14 is moved by the conveyor 19 through the stations 22 and 25 along a circular path and transports the respective containers 2 from the station 22 to the station 25 along the arc-shaped path.

  Referring to FIG. 1, the filling station 6 has an annular chamber 28 arranged around the shaft 20 and connected to the end of the supply line 7 and to all devices 15.

  Each device 15 includes a fastening body (not shown) coupled to a conveyor 19, an internal chamber (not shown) having a lower outlet 30, and an inlet 31 (which passes through the outlet 30 in the mouth of each container 2. In communication with the annular chamber 28 for receiving liquid that must be supplied to the Each device 15 further includes a stopper device (not shown) that is controlled to open / close the outlet 30 to allow / block liquid flow to the respective container mouth.

  The device 15 preferably includes a respective intake port 33 that is connected to a vacuum source 34 using an air line 35 to remove air from the container 2 before filling the container 2. In addition, the device 15 includes a respective gas port 36 that is in permanent communication with a gas line 37. Each gas port 36 is filled with a gas inlet or a container 2 for pressurizing each container 2 with a gas supplied by a gas line 37, in particular with carbon dioxide, before filling the container 2 with liquid. In this case, one of the gas outlets for allowing the gas flowing out from the container 2 to flow into the gas line 37 is defined. Thus, line 37 is the only gas conduit for supplying gas to device 15 and receiving gas from device 15.

  In addition, the filling machine 1 includes a liquid tank 8 and a known cleaning system 39 connected to the filling station 6.

  The gas line 37 includes a shut-off valve (not shown), defines a portion of the gas system 40, and further includes a gas tank or gas accumulator 41, which is connected to the end of the gas line 37 and is a filling station. 6 outside. The gas system 40 is separate and independent from the upper part 9 of the liquid tank 8, ie there is no fluid communication between the upper part 9 and the gas system 40.

  The gas tank 41 may include a pressure sensor, a level sensor, a drainage device, a safety valve, a filter, and the like, which are not shown in detail.

  The gas tank 41 is connected to a pressurized gas source 42 similar to the source 10 by means of a regulating valve 44, which electronically opens and closes the gas flow path between the source 42 and the line 37. It is automatically controlled by the control unit 45. When the valve 44 is opened to allow gas flow, the source 42 supplies gas into the gas tank 41, thus increasing the pressure within the entire gas system 40.

  The gas tank 41 is also connected to the discharge opening 46 by means of a regulator valve 48, which is also provided by the unit 45 to open / close the gas flow path between the line 37 and the external environment. Automatically controlled. When the valve 48 is opened to allow gas flow, gas is vented from the gas tank 41 to the atmosphere, thus reducing the pressure within the entire gas system 40. Preferably, the opening 46 includes a silencer (not shown) for reducing noise of gas flowing out from the gas tank 41. Preferably, the valves 44, 48 are connected to the gas tank 41 using a separate pipe from the gas line 37, or they are mounted directly on the gas tank 41.

  Before being filled with liquid, each container 2 performs several preliminary steps, in particular a first evacuation step (in which air is drawn from the container 2 using the vacuum source 34), and flushing. A process (in which gas is supplied from the gas port 36 into the container 2 and mixed with the remaining air) and a second exhaust process (in which mixing of residual air and gas is a vacuum source) And a pressurizing step (in which gas is supplied from the gas port 36 into the container 2 in order to pressurize the container 2).

  After pressurization, the stopper device is opened and the container 2 is filled. In particular, the filling may include a fast first filling step followed by a slow second filling step. For the purpose of controlling the start and / or stop of the first and second filling steps, each filling device further comprises a sensing device (in particular a probe) for detecting the level of liquid inside the container 2. .

  After filling the container 2 with liquid, the gas still present in the neck 5 is depressurized, so that the pressure above the liquid is equal to atmospheric pressure.

  During the filling process, gas flows out of the container 2 towards the gas line 37 and thus towards the gas tank 41. Thus, during filling, the gas back pressure in the container 2 is defined by the pressure in the gas line 37. On the other hand, the liquid supply pressure in the line 7 is defined only by the static head in the liquid tank 8.

  The unit 45 has a controller that controls the opening and closing of the valves 44 and 48 as a function of the feedback value defined by the pressure difference between the supply line 7 and the gas line 37. Preferably, this feedback value is detected by a differential pressure sensor 51, which receives the pressure fluid signal from both lines 7 and 37 and produces an electrical signal corresponding to the detected pressure difference, Send to unit 45. Alternatively (not shown), the feedback value may be calculated as the difference between two pressure values detected by respective pressure sensors located along lines 7 and 37. The unit 45 compares the feedback value with the set value S defined by a single value or range and turns the valves 44 and 48 so that the pressure difference between the lines 7 and 37 reaches the set value S. Control. The set value S may be derived from data stored in the memory of the unit 45 or may be set using a remote interface. In particular, the set value S is variable as a function of the type of filling process and / or as a function of the type of liquid. Preferably, the controller of unit 45 is a PID controller.

  As mentioned above, according to the present invention, the pressure in the gas system 40 is controlled so that the pressure difference between the lines 7 and 37 is maintained at a level defined by the setpoint S, With the control performed by the unit 45. In particular, as the liquid level in the liquid tank 8 decreases, the hydrostatic head gradually decreases, but the control performed by the unit 45 on the valve 48 corresponds to the pressure in the gas tank 41 (and hence line 37). Decrease with the technique. In other words, the unit 45 controls the opening of the valve 48 in order to discharge the gas from the gas tank 41 when the feedback value becomes lower than the set value S.

  On the other hand, when the feedback value becomes higher than the set value S, the unit 45 may control the opening of the valve 44 to recover the pressure in the gas system 40.

  In this way, since the pressure difference between the pressure of the supplied liquid and the back pressure in the container 2 is always maintained at a desired level that satisfies the requirements of the filling process, the hydrostatic head of the liquid tank 8 is Does not affect the filling process. On the other hand, the line 7 is directly connected to the liquid tank 8 between the filling station 6 and the liquid tank 8 without any buffer tank or any pump. In other words, the filling head, ie the pressure difference between lines 7 and 37, is no longer controlled by the pressure set by the feed pump, which is due to the pressure of the relatively small gas tank 41. Controlled and, in turn, controlled by two valves 44, 48.

  By way of example, the gas tank 41 has a volume of about 50-100 dm3, i.e. smaller than the usual buffer tank provided in the prior art and thus less bulky. At volumes less than about 50 dm3, the process is no longer controllable in a stable manner due to the limited response time of instruments and valves currently available on the market (in the future, by using more sensitive sensors and valves Such a minimum volume could be reduced). At volumes greater than about 100 dm 3, filling head control has a response time that is too fast for changes in the hydrostatic head in the liquid tank 8.

  Line 37 includes a tube connecting the filling station 6 to the gas tank 41 and having a length of less than about 10 meters. Furthermore, it is desirable to sense the gas pressure at a point close to the device 15.

  These last features make it possible to reach the desired back pressure in the container 2 and therefore the desired set point S with a maximum error of about 20 mbar during the transient phase of the filling process. is there. Under normal filling conditions, the maximum error is further reduced.

  On the other hand, the control of the system maintains the correct filling head with a response time of about 300 ms to changes in the hydrostatic head of the liquid tank 8.

  Moreover, the bottled liquid is more stable because it is not shaken by the pump before reaching the device 15.

  From the above-mentioned features, the supply line 7 has a simpler and cheaper solution compared to prior art solutions, since it does not require buffer tanks and / or pumps and corresponding connections. It is clear that this is possible.

  Since this solution is very simple, it is possible to easily adapt previously installed machines and / or new machine designs to provide new features.

  In addition, since there is no feed pump along line 7, less power is required to control the pressure difference between lines 7 and 37.

  Since there are no buffer tanks and pumps, less time and costs are required for maintenance and cleaning. In particular, for cleaning the filling machine 1, the consumption of chemicals and energy can be reduced by reducing the volume of the liquid supply system.

  Furthermore, the gas stored in the gas tank 41 is not contaminated because it is completely separated from the air and from the liquid stored in the liquid tank 8 and supplied by the line 7.

  Obviously, modifications may be made to the filling machine 1 described and illustrated herein without departing from the scope of protection defined in the appended claims.

  In particular, the valves 44 and 48 may be integrated into a single valve controlled by the unit 45 to seal the gas tank 41 or to selectively communicate the gas tank 41 with an external environment or a pressurized gas source. Well and / or the valves 44, 48 may be connected to the gas line 37 in the vicinity of the gas tank 41 instead of being connected directly to the gas tank 41 and / or the pressure of the line 37 is connected to the device 15. It may be sensed at a different point from the gas tank 41 (for example, it may be sensed at the conveyor 19 or at the gas tank 41).

  Finally, the filling machine 1 may advantageously be used not only for beer but also for carbonated soft drinks.

Claims (7)

A filling machine (1) for filling a container with a particularly pasteurized liquid,
A gas line (37);
A liquid supply line (7) adapted to be connected to a liquid tank (8);
At least one filling device (15),
a) an inlet in communication with the liquid supply line (7) for receiving liquid stored in the liquid tank;
b) a lower outlet for supplying the liquid into the container (2) during filling;
c) a gas port in communication with the gas line (37) and defining a gas outlet for flowing gas out of the vessel (2) towards the gas line (37) during filling; At least one filling device (15) comprising:
Connected to the gas line (37) and the liquid supply line (7) to determine a feedback value defined by the pressure difference between the liquid supply line (7) and the gas line (37) Pressure sensor means (51);
An electronic control unit configured to cause the pressure difference between the liquid supply line (7) and the gas line (37) to reach a set value (S) in accordance with the feedback value. ,
A gas tank (41) permanently in communication with the gas line (37) and separated from the liquid supply line (7);
The first valve means (44) for communicating the gas tank (41) with a pressurized gas source, and opening the first valve means (44) increases the pressure inside the gas tank (41). The first valve means controlled by the electronic control unit,
And a second valve means (48) arranged between the gas tank (41) and the exhaust opening, wherein the electronic control unit has the feedback value lower than the set value (S). A filling machine, characterized in that it is configured to open the second valve means (48) in order to exhaust gas from the gas tank (41).   The electronic control unit is configured to open the first valve means (44) to pressurize the gas tank (41) when the feedback value is higher than the set value (S). The filling machine according to claim 1, wherein:   The filling machine according to claim 1 or 2, characterized in that the gas tank (41) is external to the filling device (15) and is spaced from the filling device (15).   A filling station (6) having a conveyor (19) and a plurality of the filling devices (15) carried by the conveyor (19) is provided, and the gas tank (41) is located outside the filling station (6). 4. Filling machine according to claim 3, characterized in that it is spaced from the filling station (6).   5. The gas line (37) comprising a tube connecting the gas tank (41) to the filling station (6) and having a length of less than about 10 meters. Filling machine.   The pressure sensor means (51) is connected to the gas line (37) at a point located between the gas tank (41) and the filling device (15). The filling machine according to any one of 5.   7. The gas port according to claim 1, wherein the gas port further defines a gas inlet for pressurizing the container (2) with gas from the gas line (37) prior to filling. A filling machine according to claim 1.

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