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The present invention relates to a filling head for filling containers with pourable products, in particular carbonated liquids, such as sparkling water, soft drinks and beer, which the following description will refer to, although this is in no way intended to limit the scope of protection as defined by the accompanying claims.
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The present invention may be also used to particular advantage for any type of container, such as containers or bottles made of glass, plastics, aluminum, steel and composites, and for any type of pourable product, such as non-carbonated liquids (including still water, juices, teas, sport drinks, liquid cleaners, wine, etc), emulsions, suspensions, high viscosity liquids and beverages containing pulps.
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As known, container filling machines typically comprise conveying means to deliver a succession of empty containers to a filling unit or a plurality of filling units, where such containers are filled with a pourable product. After filling, the filled containers are removed from the filling units and are conveyed towards further processing stations in order to be closed and to be prepared for being finally delivered to sales outlets.
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A typical realization of such a container filling machine comprises a plurality of conveying carousels each adapted to rotate continuously about a respective longitudinal axis.
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A first conveying carousel is configured to act as an input star wheel for conveying the succession of empty containers towards a second conveying carousel.
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The second conveying carousel is configured to act as a filling conveyor comprising a plurality of filling units and adapted to fill the empty bottles with the pourable product.
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Each filling unit of the filling conveyor is configured to receive one respective empty container at a first transfer position from the first conveying carousel. The filling unit is also configured to keep the respective container in an essentially upright position.
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Further, each container kept in upright position by the respective filling unit is conveyed along a path from the first transfer position to a second transfer position and, thereby, is filled with a given volume of the pourable product. The filled container is transferred at the second transfer position to a third conveying carousel acting as an outlet star wheel which is configured to convey the containers towards further processing stations.
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Each filling unit comprises a filling head adapted to fill the respective empty container with the pourable product during advancement along the path from the first transfer position to the second transfer position.
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The filling carousel further comprises supply means configured to direct the pourable product from a product reservoir to the plurality of filling units and, accordingly, to the respective filling heads.
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Each filling head comprises an inlet conduit, adapted to receive the pourable product from the supply means, and a filling tube connected to the inlet conduit and adapted to feed the pourable product into the respective container. Generally, each inlet conduit cooperates with a respective valve configured to selectively allow or prevent flow of the pourable product towards the container to be filled.
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Each filling tube typically has a cylindrical configuration and crosses, with radial play, an outlet mouth of the relative filling head, adapted to close a pouring/inlet opening of the container during filling thereof.
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A common problem posed in respect of known filling machines is the formation of foam during, and at the end of, the operation of filling each container.
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This problem is mainly caused by the fact that, for reasons of economy, commercial containers are not such larger than the volume required for accommodating of the contents. Thus, during filling operations, which have to be carried out at high speed, it is common for some amount of liquid in the form of foam to bubble over the top of the container prior to the container being capped or sealed. The product loss can be as high as ten percent, which translates into higher cost for the consumer or lower profitability for the bottler, or both.
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To reduce this product loss, some filling machines include a dwell station that allows for the product foam in a recently filled container to settle prior to capping.
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Other filling machines include a short suction pipe adapted to be introduced into the container to be sealed, and a suction system whereby the foam over the top surface of the liquid is removed and optionally recycled into the product reservoir.
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Some filling machines may also use blast nozzles for blowing any drops and residual foam from the surfaces to be sealed or capped.
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Some filling machines reduce the temperature of the liquid to reduce foaming.
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In certain cases, the containers are purposefully overfilled to compensate for lost product in the form of foam and thereby achieve the desired net fill volume, which results in undesirable product loss.
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Other possible solutions are based on the use of ultrasonic waves for collapsing the foam; in practice, the portion of liquid forming the foam again becomes part of the liquid content of the container rather than being wasted.
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In general, in order to circumvent as much as possible foaming of the pourable product, the processing speed of the filling process must be reduced.
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It is therefore an object of the present invention to provide a filling head which allows to achieve high processing speeds and, at the same time, is capable of reducing formation of foam at the end of the filling process.
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According to the present invention, there is provided a filling head as claimed in claim 1.
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A preferred, non-limiting embodiment of the present invention will be described by way of example with reference to the accompanying drawings, in which:
- Figure 1 shows a schematic top plan view, with parts removed for clarity, of a container filling machine including a plurality of filling heads according to the present invention;
- Figure 2 shows a larger-scale sectional view of one filling head of the filling machine of Figure 1, with parts removed for clarity;
- Figure 3 shows a larger-scale axial section of a filling tube of the filling head of Figure 3; and
- Figure 4 shows a larger-scale detail of the filling tube of Figure 3.
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Number 1 in Figure 1 indicates as a whole a machine for filling containers, in particular bottles 2, with pourable products, in the example shown carbonated liquids, such as sparkling water or carbonated beverages, including soft drinks and beer.
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As previously indicated, machine 1 may be also used for any type of pourable product, including non-carbonated liquids (such as still water, juices, teas, sport drinks, liquid cleaners, wine, etc), emulsions, suspensions, high viscosity liquids and beverages containing pulps.
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As visible in Figure 2, each bottle 2 has a longitudinal axis A and comprises a hollow main body 3 bounded by a bottom wall 4 substantially perpendicular to axis A and by a top neck 5 substantially coaxial with the axis A; neck 5 delimits a pouring/inlet opening 6 of bottle 2 opposite to bottom wall 4.
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In the example shown, the bottles 2 filled by machine 1 are made of plastics; however, machine 1 may be also used for other types of containers, such as containers made of glass, aluminum, steel and composites.
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With reference to Figure 1, machine 1 comprises a conveying device 7 that serves to advance a succession of bottles 2 along a path P and to fill them while they are moving along such path.
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In the preferred embodiment illustrated in Figure 1, the conveying device 7 comprises a filling carousel 8, which is mounted to rotate continuously (anticlockwise in Figure 1) about a vertical axis B perpendicular to the Figure 1 plane.
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Carousel 8 receives a succession of empty bottles 2 from an inlet star wheel 9, which is connected to the carousel 8 itself at a first transfer station 8a and is mounted to rotate continuously (clockwise in Figure 1) about a respective longitudinal axis C parallel to axis B.
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Carousel 8 releases a succession of filled bottles 2 to an outlet star wheel 10, which is connected to the carousel 8 itself at a second transfer station 8b and is mounted to rotate continuously (clockwise in Figure 1) about a respective longitudinal axis D parallel to axes B and C.
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Machine 1 further comprises a plurality of filling units 11, which are equally spaced angularly about axis B, are mounted along a peripheral portion 8c of carousel 8, and are moved by the carousel 8 itself along path P extending about axis B from transfer station 8a to transfer station 8b.
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With reference to Figure 2, each filling unit 11 comprises a support plate 12 adapted to receive and retain a relative bottle 2 in a vertical position, in which such bottle 2 has its axis A parallel to the axis B of carousel 8, and a filling head 13 for feeding the pourable product into a relative bottle 2 as the support plate 12 travels along path P.
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Each filling head 13 is conveniently arranged above the bottle 2 to be filled.
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In particular, when received in a relative filling unit 13, each bottle 2 rests with its bottom wall 4 on the relative support plate 12 and extends vertically from the latter.
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Support plate 12 is conveniently supported by peripheral portion 8c of carousel 8.
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Each filling head 13 comprises a support block 14 secured, in a manner known per se and not shown, to the peripheral portion 8c of carousel 8; and a hollow body 15 suspended from support block 14 , facing support plate 12 and defining a central through opening 16 of axis E parallel to axes B, C and D.
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As filling heads 13 are identical to each other, only one of them will be described in detail hereafter for the sake of clarity and simplicity.
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In particular, hollow body 15 of filling head 13 terminates towards the relative support plate 12 with an outlet mouth 19 configured to close pouring/inlet opening 6 of the respective bottle 2 during filling thereof.
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Filling head 13 further comprises a filling tube 17 coaxially mounted through a bottom part of opening 16 of main body 15 and crossing with radial play outlet mouth 19 to feed the pourable product into the relative bottle 2.
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More specifically, filling tube 17 protrudes from outlet mouth 19 towards support plate 12 so as to extend in use within bottle 2.
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Outlet mouth 19 and filling tube 17 define an annular gap 23 therebetween, whose function will be explained later on.
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In the preferred embodiment shown in Figure 2, outlet mouth 19 of filling head 13 is adapted to contact in use an upper annular edge 5a of top neck 5 of the relative bottle 2.
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Filling tube 17 receives the pourable product from a reservoir R through an inlet conduit 20. In the example shown, the terminal part of inlet conduit 20 is defined by an upper portion of opening 16 of hollow body 15 communicating at the bottom with filling tube 17.
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A valve 18 is conveniently arranged within the terminal part of inlet conduit 20 and is selectively set in an open and a closed position, in which it respectively allows or prevents flow of the pourable product through the filling tube 17.
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Additionally, filling head 13 comprises means (not shown and known as such) to pressurize the bottles 2 with a pressurizing gas prior to filling, and a depressurizing circuit 25 for discharging the gas escaping from the relative bottle 2 during filling.
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In particular, the annular gap 23 between outlet mouth 19 and filling tube 17 defines an intake portion of depressurizing circuit 25. As schematically shown in Figure 2, depressurizing circuit 25 further comprises a gas reservoir G and fluidic connecting means 27 adapted to fluidically connect the annular gap 23 with the gas reservoir G.
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With reference to Figures 3 and 4, filling tube 17 comprises:
- an inlet portion 28 configured to receive the pourable product from product reservoir R;
- an outlet portion 29 adapted to release the pourable product; and
- an intermediate portion 30 adapted to convey the pourable product from the inlet portion 28 to the outlet portion 29.
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In particular, intermediate portion 30 of filling tube 17 presents an essentially cylindrical-like shape delimited by an inner and an outer cylindrical surface 31, 32. More specifically , intermediate portion 30 has an inner diameter ID1 and an outer diameter OD1.
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Outlet portion 29 of filling tube 17 presents a cylinder-like shape delimited by an inner and an outer cylindrical surface 33, 34. More specifically, outlet portion 29 has an inner diameter ID2 and an outer diameter OD2.
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Furthermore, inner cylindrical surface 31 of intermediate portion 30 and inner cylindrical surface 33 of outlet portion 29 are connected by an inner transition surface 35 having a truncated-cone shape.
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Outer cylindrical surface 32 of intermediate portion 30 and outer cylindrical surface 34 of outlet portion 29 are connected by an outer transition surface 36, also having a truncated-cone shape.
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Intermediate portion 30 and outlet portion 29 are advantageously configured so that inner diameter ID2 is larger than inner diameter ID1.
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In practice, the outlet portion 29 is internally expanded with respect to the intermediate portion 30.
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Further, outer diameter OD2 is also larger than outer diameter OD1.
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Hence, outlet portion 29 is also externally expanded with respect to the intermediate portion 30.
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In other words, filling tube 17 has a radially widened outlet portion 29.
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In the example shown, inner diameter ID2 is equal to outer diameter OD1.
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In practice, filling tube 17, and in particular intermediate portion 30 and outlet portion 29 thereof, are configured so that, in use, the flow speed of the pourable product decreases by proceeding towards the relative bottle 2. The flow rate of the pourable product moving through the filling tube 17 is maintained constant at the various sections thereof.
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Clearly, changes may be made to filling head 13 and filling machine 1 as described herein without, however, departing from the scope of protection as defined in the accompanying claims.
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In particular, the filling tube 17 with a radially expanded outlet portion 29 may be also used for filling containers or bottles 2 without contact between the latter and the relative filling head 13.
