Patent Application
20140144543
This application claims priority from German Patent Application No. 10 2012 111 552.4, filed on Nov. 28, 2012 in the German Patent and Trademark Office, the disclosure of which is incorporated herein by reference in its entirety.
1. Technical Field
The present invention relates to a filling element for filling a container with a fill product, such as a piston filler, a free-jet filler or a dosing unit for filling viscous, paste-like or fluid food products, such as for filling beverages.
2. Related Art
Various filling elements are known for filling with fill products, particularly fluid or paste-like fill products or fill products which have high viscosity. For example, so-called free jet fillers are often used for filling dairy products and juices, in which the fill product flows into the container to be filled from a fill product outlet of the applicable filling element in free fall, i.e. without the influence of any conveying devices. The flow of the applicable fill product through such a free-jet filler is usually controlled by a valve, which comprises a valve cone accommodated in a valve seat which is formed to be complementary to the valve cone. The filling process is started by lifting the valve cone out of the valve seat, and the filling process is ended by subsequently lowering the valve cone onto the valve seat. During filling, the fill product flows around the valve cone, with the result that after completion of the filling process, fill product can adhere to the underside of the valve cone, and subsequently drip through the fill product outlet in an uncontrolled manner.
It is further known, in order to fill paste-like fill products or fill products with high viscosity, for example ketchup, syrup, baby food, apple puree or similar, to use piston fillers, in which the applicable fill product is pushed out by the use of a suitable dosing piston. Piston fillers usually comprise a fill product outlet in the form of a drilled discharge aperture which, at the end of a filling cycle, is emptied by the pushing of an appropriately operated plunger, which is usually formed as a cylindrical rod. When such a plunger is used to empty fully the drilled discharge aperture, it can occur that residues of the fill product adhere to the front surface of the plunger, and again drip subsequently in an uncontrolled manner.
When containers are filled with fill products, and in particular filled with food products and beverages, it is essential that the applicable filling devices are operated hygienically. It is therefore necessary to prevent the fill product from dripping after filling, for example onto containers that are yet to be filled and/or containers that are already filled, in order to avoid subsequent formation of germs or mold, for example on the outside of the filled containers or in the area of their screw caps.
Furthermore, it is also essential for the subsequent closure of filled containers, in some closure processes, for the mouth area of the filled container also to be completely clean and free of fill product. This is in particular the case when, for example, a hygienic seal in the form of a foil lid is to be affixed by adhesive to the periphery of the mouth, as is usual for example in the field of filling dairy products or food products for infants.
From U.S. Pat. No. 7,743,798 B2, a filling nozzle is known wherein a net is disposed below the discharge port for the product to be filled. The fluid is dispensed though this net. After the filling process is completed, the filling piston is pulled back a little, so that the fill product is sucked back such that subsequent dripping is reduced and the fill fluid is retained at the net. In other words, an attempt is made to avoid dripping after filling by sucking the fill product back.
From U.S. Pat. No. 7,011,117 B1, a filling valve with a plunger mechanism is known.
Proceeding from the above-mentioned background, a filling element for filling containers with a fill product is provided, in which uncontrolled subsequent dripping is further reduced.
According to one embodiment, a filling element for filling a container with a fill product is proposed, such as a free-jet filler valve, a dosing unit or a piston filler in a filling plant for fluid, paste-like or viscous food products, wherein the filling element has a fill product outlet and an operating element disposed in direct contact with the fill product outlet for influencing the discharge of the fill product from the fill product outlet. An ejection device may be provided on the operating element for ejecting a fill product residue in the direction of discharge.
By providing, on the operating element, the ejection device, which is provided for ejecting a residue of fill product in the direction of discharge when the filling is finished, such as immediately after the filling is finished, it is possible to eject in a controlled manner in the direction of discharge any fill product that still adheres to the operating element, i.e., for example to the plunger of a piston filler or the valve cone of a filling valve. Accordingly, fill product residues which still adhere to the operating element after the filling process is finished are ejected directly into the container to be filled, with the result that the tendency for subsequent dripping can be effectively reduced, or subsequent dripping can even be prevented completely.
The phrase “eject in the direction of discharge” used herein is understood to mean not only ejection of the fill product residue in the direction of the axis of the filling element, but in general the ejection of the fill product residue in the direction of the container which has been or is to be filled.
In the manner described above, it is possible to eject the fill product residue which still adheres to the operating element after completion of the actual filling process, i.e., for example after the closing of the filling valve of a filling element. Advantageously, this takes place at exactly the moment when the end of the stream of fill product leaves the filling element.
Furthermore, for example in the case of a dosing unit or a piston filler, it can be achieved that, after the fill product is pushed out of the applicable drilled discharge aperture by means of the plunger, any residues of fill product that still adhere to the front of the plunger can also be ejected in the direction of discharge by means of the ejection device, with the result that the residues of fill product can be received in the filled container, and in this manner subsequent dripping can be prevented.
The ejection by means of the ejection device may take place such that no splashing occurs and the fill product residues that are ejected in the direction of discharge by means of the ejection device do not lead to contamination of the container which has already been filled. This can be achieved by the ejection device and/or the ejection forces that are applied being symmetrical in form in one embodiment.
In one embodiment, the operating element is the valve cone of a filling valve, which may be accommodated in a valve seat formed to be complementary to it.
In a further example embodiment, the operating element is a plunger of a dosing unit, wherein the ejection device is preferably disposed on the front surface of the plunger facing the direction of discharge.
The ejection device may comprise a gas-permeable membrane for applying a stream of gas in the direction of discharge. For this, a gas path may be disposed in the operating element itself for applying the stream of gas to the membrane, and through the membrane in the direction of discharge. The gas-permeable membrane may be formed to be permeable to the stream of gas but impermeable to the fill product itself. It is thus impermeable to fluid and particularly impermeable to water. As a material for the membrane, a PTFE material can for example be used, resulting in a membrane which, while gas-permeable, is fluid-impermeable.
The stream of gas may be configured such that it is applied at the end of each filling process, thus for example after the full lowering of a valve cone into its valve seat to stop the stream of fill product, or after the full advance of the plunger in a drilled discharge aperture of a piston filler or a dosing system when the front surface of the plunger reaches the lower dead center, so that residues of fill product still adhering to the valve cone or plunger are flushed away or pushed out by the gas stream.
In order to eject the residues as evenly as possible, a suitable diffuser or flow straightener may be provided in the gas stream before the membrane in order to equalize, to a large extent, the gas stream over the entire surface of the membrane. In this manner an even ejection of the fill product residues can be achieved, so that splashing of the residues of the fill product can be reduced or prevented completely.
As diffusers or flow straighteners for the gas stream before the gas-permeable membrane, it is possible to use for example screens, screen packs, porous fillings or straighteners.
When such an ejection device, comprising a gas-permeable membrane to apply a stream of gas in the direction of discharge, is used in a dosing unit with a plunger, the plunger shaft may be hollow in form. This hollow form of the plunger shaft is actually contrary to the usual design of such plunger shafts known from the state of the art, since conventional plunger shafts need a closed front surface in order to perform their function. By means of the hollow plunger, however, it is possible to convey the stream of gas to the gas-permeable membrane.
In one embodiment, when using an ejection device comprising a gas-permeable membrane, to use a sterile gas, such as an inert gas, to provide the stream of gas. This enables the stream of gas to apply gas at the same time to the head area of the filled container, such that the inert gas in the head area displaces gas which contains oxygen, in order to improve the storage life of the fill product in the container. It can thus be achieved by the application of gas to the head area that the fill product does not react with oxygen, and accordingly retains its original properties. Examples of the inert gas include N2, CO2, argon or a similar gas which can serve to rinse the head area of the filled container.
In another embodiment, the ejection device comprises a vibration means for vibrating an area of the operating element that can be brought into contact with the fill product. Accordingly, the application of suitable vibration of the applicable contact area of the operating element can achieve the ejection in the direction of discharge of any residues of fill products that may be present, after the filling process is completed, and particularly after a plunger shaft has reached its lower dead center or a valve cone is received in its valve seat.
In another embodiment, the ejection device comprises a membrane that is expandable in the direction of discharge, which can be expanded by means of pressurization or by means of a suitably drivable mechanical expansion element. The membrane may be pre-stressed in the initial non-expanded state, so that the membrane returns to the initial state when for example the effect of the pressure or of a mechanical expansion element ceases.
By the use of such a membrane which is expandable in the direction of discharge, it is again possible to eject residues of fill product that adhere to the operating element, for example to a valve cone or the front surface of a plunger, by means of a suitably sudden expansion of the expandable membrane in the direction of discharge, in such a manner that, after completion of the filling process, the residue of fill product is also introduced into the filled container and subsequent dripping can be avoided.
A hollow plunger shaft or a hollow valve shaft thereby may serve as the accommodation for the means of operation of the ejection device.
Further embodiments and aspects of the present invention are more fully explained by the description below of the figures. The figures show:
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 the description below, in order to avoid redundancy.
An operating element 2, in the form of a plunger shaft 26 for pushing out the residues of fill product after completion of the filling process, is displaceably disposed in the drilled discharge aperture 20. Accordingly, following the actual dispensing process carried out by the lowering of the dosing piston 3, the fill product that is still in the drilled discharge aperture 20 is ejected in the direction of discharge A by means of the lowering of the plunger shaft 26. When this takes place, however, a residue of fill product often remains on the front surface 24 of the plunger shaft 26, said residue adhering to the front surface 24 of the plunger shaft 26. Subsequent uncontrolled dripping can consequently occur if the residues of fill product that remain on the front surface 24 of the plunger fall off after the filling process ends.
In the example embodiment shown, the dosing piston 3 is mechanically operated via a roller 30, which is driven by a positive cam which is not shown. In the example embodiment shown, the plunger shaft 26 is also controlled by means of a roller 22 driven mechanically by a positive cam. A control valve 4 is further provided, which is configured to convey the fill product to the dosing piston 3 again after the latter has been fully lowered. By subsequent raising of the dosing piston 3, with a corresponding valve position of the control valve 4, fill product is again drawn into the dosing cylinder 32. The valve 4 is then switched back to the direction of ejection, so that the filling process can again be performed, and in particular so that the fill product in the dosing cylinder 32 can again, by the lowering of the dosing piston 3, be ejected through the drilled discharge aperture 20, and can be dispensed into the container that is to be filled.
The ejection device 5 is in the form of a gas-permeable membrane 50, which is only schematically indicated here. The plunger 2 or the plunger shaft 26 is hollow in form, and has a gas path 28, through which a gas can be applied under pressure to the gas-permeable membrane 50. By supplying the gas via the gas path 28, a stream of gas is applied in the direction of discharge A to the ejecting device 5. The stream of gas passes through the membrane 50 and thereby provides a stream of gas leaving the membrane 50 in the direction of discharge A. By means of the stream of gas, residues of fill product which adhere to the front surface 24 and in particular to the membrane 50 of the plunger 2 are pushed off of the membrane in the direction of discharge A. Because the stream of gas can be applied to the membrane 50 at any desired time, the residue of fill product which adheres to the front surface 24 of the plunger 2 can also be ejected in a controlled manner at a predetermined and/or controlled time.
In one embodiment, the gas stream is applied at exactly the moment when the filling process is completed, the plunger 2 is at its lower dead center, and the filled container is still under the fill product outlet 200. In this manner it is possible to eject the fill product adhering to the operating element in the form of the plunger shaft 26 into the filled container underneath. It is thereby possible to ensure that the fill product does not subsequently drip in an uncontrolled manner, or else it is thereby possible to reduce the tendency of the fill product to drip subsequently, since residues of fill product adhering to the plunger have been ejected.
By this means it can be achieved that the container that is yet to be filled, or is already filled, is not subject to contamination of its outside or its mouth area, with the result that the subsequent closure can be performed reliably. In this manner it is possible to prevent the formation of germs or mold on the outside of a container or in a mouth area of the container. Furthermore, the application for example of a foil closure to the periphery of the mouth can be performed reliably.
The gas that is passed through the gas path 28 of the plunger 2, i.e., in particular the hollow plunger shaft 26, is an inert gas in one embodiment, which can also be used at the same time to rinse the head area of the filled container. As inert gases, it is possible to use for example N2, CO2 or argon.
The membrane 50 may be formed to be gas-permeable, but impermeable to the actual fill product. Accordingly, the downward movement of the plunger 2 at the end of the filling process can push the fill product out of the drilled discharge aperture 20 without problems, but the fill product is unable to pass through the membrane 50 into the hollow space behind, in particular into the gas path 28 of the plunger 2. Such a membrane which is gas-permeable but impermeable to the fill product, for example a high-viscosity fluid, can be manufactured for example from PTFE.
In order to prevent the splashing and/or non-symmetrical ejection of the fill product residues, or at least to reduce the tendency for such a non-symmetrical ejection, a suitable diffuser or flow straightener 6 is provided before the membrane 50 in the example embodiment shown in
In other words, the proposed ejection device does not achieve the prevention of subsequent dripping by the means known in the state of the art of retaining or sucking back fill product residues; on the contrary, it achieves this by active and controlled ejection of the fill product residues.
To end the filling process, the valve cone 72 is lowered again such that it comes into contact with the valve seat 70 and closes the channel for the fill product. As is immediately clear from
An ejection device 5 is therefore provided on the valve cone 72, wherein the ejection device 5 is provided in the form of a membrane 50 which has approximately the same characteristics as the membrane 50 from
In order to enable the ejection of fill product residues in the direction of discharge A, the valve shaft 74 is formed with a gas path 76, through which a gas under pressure can be applied to the membrane 50 such that it flows through the membrane 50. By means of the stream of gas flowing through the membrane 50, adhering fill product residues are ejected in the direction of discharge A.
In this case, the filling process takes place in that the valve cone 72 is initially lifted out of the valve seat 70, with the result that the fill product can flow out through the fill product outlet 200 in the direction of discharge A into the container that is to be filled. After the filling process is completed, the valve cone 72 is correspondingly lowered back onto the valve seat 70, so that the stream of fill product is interrupted.
After the valve cone 72 is fully lowered into the valve seat 70, a gas is conveyed via the gas path 76 through the membrane 50, ejecting any fill product residues that may adhere to the membrane 50 into the already filled container disposed beneath.
In this manner, reliable active support for the draining and ejection of the fill product residues is again achieved. Contamination of the outside and mouth area of the container can thereby be reduced or completely prevented.
In the example embodiment shown in
After the plunger 2 of a piston filler reaches its lower dead center, and after the fill product residues have been pushed out, the vibration means 52 is operated such that any fill product residues that may adhere to the attachment 54, particularly in the area of the front surface 24, are ejected by the vibration in the direction of discharge A.
In a further example embodiment, which is shown schematically in
When such an expansion, preferably a sudden expansion, is carried out in the direction of discharge A, any fill product residues that may still adhere to the membrane 56 receive an impulse in the direction of discharge A, and are accordingly ejected. If the expandable membrane 56 is to be pressurized by a gas, it may be formed to be gas-tight, in order to enable the membrane to expand.
The membrane 56 may be pre-stressed in the initial position, i.e., the non-expanded position. Accordingly, it returns to the initial position after the cessation of the gas pressurization or the mechanical energy from the mechanical expansion element 58, in order to be fully ready for use after the next filling cycle.
To the extent applicable, all individual features described in the individual example embodiments can be combined with each other and/or exchanged, without departing from the field of the invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2012 111 552.4 | Nov 2012 | DE | national |
