Dosing device and dosing method for liquids

Abstract

The invention relates to a dosing device having an inlet for a liquid to be delivered to a container as a dose, in particular a beverage. The device comprises a valve seat, a sealing element interacting with the valve seat and an outlet for the dose of the liquid. In order to reduce foam build-up upon delivering the liquid into the container, according to the invention the sealing element can be moved to a first and a second opening position, wherein, in the second opening position, the flow cross-section area between the valve seat and the sealing element is larger than in the first opening position. In addition, the invention relates to a dosing method comprising the supplying of a liquid to a valve which is moved to a first and second opening position.

Claims

1. A liquid flow control device configured to conduct a filling operation for filling a metered quantity of liquid into a package, comprising: an inlet and an outlet; a valve seat; a sealing element cooperating with the valve seat, the sealing element being movable to a first open position and a second open position, a flow cross section between the valve seat and the sealing element in the second open position being larger than the flow cross section between the valve seat and the sealing element in the first open position, the sealing element comprising a first part and a second part that encircles at least a portion of the first part, the second part having an inner surface facing an outer surface of the first part; an outflow piece disposed at the outlet and having a plurality of passages arranged next to each other, an end surface of the outflow piece facing the sealing element forming at least part of said valve seat, wherein the first and second parts of the sealing element can be respectively positioned on orifices of said passages to close all passages of said plurality of passages in a closed position of the sealing element, and the first and second parts being configured so that passages closable by the first part are open and passages closable by the second part are closed in the first open position and passages closable by both the first and second parts are open in the second open position, the sealing element allowing a filling liquid to flow through the outflow piece and form a filling jet for the filling operation when the sealing element is not in the closed position, wherein a gap formed between the outer surface of the first part and the inner surface of the second part defines the flow cross section when the sealing element is moved from the closed position to the first open position, and a size of the flow cross section defined by the gap increases as the first part is moved toward the first open position; a sleeve connecting the first part to the second part, the sleeve being connected at an upper portion of the inner surface of the second part that forms the gap and having a first sleeve portion that extends from the upper portion of the inner surface of the second part toward the outer surface of the first part and a second sleeve portion that extends upward from the first sleeve portion along the outer surface of the first part, wherein an upper end of the second sleeve portion has a stop that cooperates with a shoulder that extends around a circumference of the first part, and the sleeve has a plurality of sleeve passages around a circumference thereof, the sleeve passages allowing the filling liquid to flow from an outer side to an inner side of the sleeve and through the gap between the first part and the second part; and a force-transmission device connected to the first part for opening the sealing element.

2. The liquid flow control device of claim 1, wherein the gap is a ring-shaped gap.

3. The liquid flow device of claim 1, wherein the force-transmission device is connected to the first part for opening the sealing element, wherein the first part is connected to the second part such that the second part rests on the valve seat until the first opening position is reached.

4. The liquid flow device of claim 1, wherein the first part is a driver and the outer surface is a cylindrical outer surface extending vertically, the second part is a valve body and the inner surface is a frustum-like surface, and the frustum-like surface forms an acute angle with the cylindrical outer surface.

5. The liquid flow device of claim 1, further comprising a linear drive controlling a velocity of the force-transmission device when moving the sealing element from the closed position to the first open position to create a pressure profile for the filling jet, the pressure profile being adapted to the filling liquid to be dispensed to minimize an impact of the liquid on a bottom of the package at a beginning of the filling operation.

6. The liquid flow device of claim 1, wherein each of the sleeve passages extends through both the first sleeve portion and the second sleeve portion.

7. The liquid flow device of claim 1, wherein the device comprises a housing defining the inlet and the outlet, and a membrane is connected between the housing and at least one of the force-transmission device and the first part of the sealing element to prevent the intrusion of dirt and escape of liquid, the membrane having a first end connected to the at least one of the force-transmission device and the first part of the sealing element and a second end connected to the housing, the first end being movable relative to the housing with a movement of the first part of the sealing element.

8. A liquid flow control method for conducting a filling operation for filling a metered quantity of liquid into a package, comprising: feeding a liquid to a valve having an outflow piece with a plurality of passages, wherein all passages of the plurality of passages are closed by a first part and a second part of the valve in a closed position, the second part having an inner surface facing an outer surface of the first part, the first part being connected to the second part by a sleeve that is connected at an upper portion of the inner surface of the second part, the sleeve having a first sleeve portion that extends from the upper portion of the inner surface of the second part toward the outer surface of the first part and a second portion that extends upward from the second part along the outer surface of the first part, wherein an upper end of the second sleeve portion has a stop that cooperates with a shoulder that extends around a circumference of the first part, the sleeve allowing relative movement between the first part and the second part; opening the valve from the closed position to a first open position in which passages closable by the first part are opened and passages closable by the second part are closed, wherein a gap formed between the outer surface of the first part and the inner surface of the second part defines a flow cross section between the valve and the outflow piece, a size of the flow cross section defined by the gap increasing as the first part is moved toward the first open position, and wherein the sleeve has a plurality of sleeve passages around a circumference thereof, the sleeve passages allowing the filling liquid to flow from an outer side to an inner side of the sleeve and through the gap between the first part and the second part; opening the valve from the first open position to a second open position in which passages closable by the first part and the second part are opened, the flow cross section of the valve in the second open position being larger than the flow cross section of the valve in the first open position, whereby the valve allows a filling liquid to flow through the outflow piece and form a filling jet for the filling operation when the valve is not in the closed position, wherein the flow cross section of the valve in the first open position is encircled by an additional flow cross section of the valve in the second open position.

9. The liquid flow control method of claim 8, further comprising the step of controlling a velocity of the valve when moving the valve from the closed position to the first open position to create a pressure profile for the filling jet, the pressure profile being adapted to the filling liquid to be dispensed to minimize an impact of the liquid on the bottom of the package at the beginning of the filling operation.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention is explained in greater detail below on the basis of an exemplary embodiment of an inventive metering device:

(2) FIG. 1 shows a cross-sectional side view of an inventive metering device; and

(3) FIGS. 2-5 shows the metering device according to FIG. 1 with the two-part sealing element in different positions.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(4) A metering device 1 comprises, in part, a valve housing 2, which is arranged on a cover plate 3 of a filling chamber. In the filling chamber (not shown), containers, especially packages of laminated material, are filled with a liquid such as juice. The outlet 4 of the metering device 1 is aligned with a passage 5 in the cover plate 3 corresponding to the cross section of the outlet. Underneath the cover plate 3, a cylindrical outflow piece 6 is arranged concentrically to the outlet 4 of the metering device. The outflow piece 6 could also, of course, be fastened indirectly to the metering device 1.

(5) The outflow piece 6 is divided functionally into a central outflow section 7 and a peripheral outflow section 8 surrounding the central one. Both the central outflow section 7 and the peripheral outflow section 8 are formed by several cylindrical, preferably circular-cylindrical, passages 9 arranged next to each other in the axial direction of the outflow piece 6.

(6) A two-part sealing element with freedom to move up and down is provided in the valve housing 2; this element comprises a central plunger 10 as its first part and a ring-shaped valve body 11, surrounding the plunger 10, as its second part.

(7) The plunger 10 has a central sealing plate 12 on its end surface, and the valve body 11 has a ring-shaped sealing plate 13 on its end surface; in the closed state of the sealing element, these plates rest jointly on the top surface 14 of the outflow piece 6 with a sealing action. The top surface 14 thus forms at the same time the valve seat for the sealing element. Of course, the valve seat could also be designed as a component of the valve housing 2, such as a circumferential, inward-pointing web extending around the outlet 4, on which the outer edge of the ring-shaped sealing plate 13 is seated.

(8) The central plunger 10 is connected to a control rod 15 for opening and closing the sealed element. The control rod 15 is connected to a linear drive 34. The ring-shaped valve body 11 is connected to the plunger 10.

(9) Above the central sealing plate 12, the plunger 10 comprises a section designed as a driver 16; the transition of this section to the section of the plunger 10 of smaller diameter located above it forms a circumferential shoulder 17.

(10) Around its central opening 18, the ring-shaped valve body 11 comprises a driver sleeve 19 extending upward and around the plunger 10; at its upper end, this sleeve comprises a stop 20, which cooperates with the shoulder 17. In this way, the driver sleeve 19 connects the valve body 11 to the plunger 10. The driver sleeve 19 is provided with several passages 21 around its circumference.

(11) An upward-pointing, diverging, preferably frustum-like surface 23 of the valve body 11 is located opposite the essentially vertical, cylindrical, preferably circular-cylindrical surface of the driver 16 on the plunger 10. Between the essentially vertical surface of the driver 16 on the plunger 10 and the opposing, slanted surface 23 of the valve body 11, an acute angle is formed, so that, when the plunger 10 is opened, a small ring-shaped gap 24 is created between the plunger 10 and the valve body 11. In addition, in the second open position of the metering device, which is shown in FIG. 1, a larger ring-shaped gap 25 is created between the ring-shaped sealing plate 13 of the valve body 11 and the top surface 14 of the outflow piece 6.

(12) So that the plunger 10 and the valve body 11 are in defined positions with respect to each other in every position of the sealing element, and so that the ring-shaped sealing plate 13 adequately seals the passages 9 in the outflow piece 6, a compression spring 26 is provided, one end of which is supported on the top surface of the valve body 11, whereas the other end is supported on a spring plate 27 arranged on the upper section of the plunger 10.

(13) Finally, the valve space formed by the valve housing 2 is provided with an inlet 28 for the liquid to be dispensed; the inlet is connected to a supply tank (not shown).

(14) To actuate the plunger 10 and the valve body 11 attached to it, the plunger 10 is connected to the control rod 15, which is guided through a housing cover 29 with a slide guide 30. To prevent the intrusion of dirt and the escape of liquid through the slide guide 30, a membrane 31, which ensures a hermetic seal of the valve space against the slide guide 30, extends between the valve housing 2 and the plunger 10.

(15) The way in which the metering device 1 operates is illustrated in FIGS. 2-5.

(16) In FIG. 2, the metering device 1 is closed. The plunger 10 and the valve body 11 are both in their lower, closed positions, and thus they and their sealing plates 12, 13 form a sealing unit, which covers both the central and the peripheral outflow sections 7, 8. The liquid present in the valve space cannot flow into the container to be filled.

(17) In FIG. 3, the plunger 10 is raised. Now a first, small quantity of liquid, which has been waiting at the passages 21 through the driver sleeve 19 on the plunger 10, can flow through the small ring-shaped gap 24 and then through the central outflow section 7 into the container.

(18) The velocity at which the plunger 10 is raised into the first open position of the sealing element shown in FIG. 4 and then lowered back down again into the closed position is preferably variable, as a result of which, in conjunction with the slanted surface 23 of the valve body 11, which forms the angle (), it is possible to open the outflow channels in a controlled manner and thus to reduce the pressure. This achieves the goal of minimizing the impact of the liquid on the bottom of the container at the beginning of the filling operation.

(19) By the time the first open position is reached, the container bottom is covered with a first layer of liquid, and the shoulder 17 of the driver 16 of the plunger 10 has run up against the stop 20 on the driver sleeve 19 of the valve body 11.

(20) During the further course of the upward movement, the shoulder 17 of the plunger 10 carries the valve body 11 up along with it from the lower closed position into the second open position of the sealing element, shown in FIG. 5. As a result, the entire top surface 14 of the outflow piece 6 is released, so that now the intensity of the liquid flow can increase gradually to its maximum as the liquid flows through both the small ring-shaped gap 24 and the large ring-shaped gap 25 into the container. This continues until the control rod 15 moves the plunger 10 back down again.

(21) During this downward movement, the valve body 11 by means of the compression spring 26 is pressed first onto the top surface 14 of the outflow piece 6 (FIG. 4), as a result of which the filling jet is decreased in a manner which is the reverse of that in which it was increased. During the following further downward movement of the plunger 10 into the closed position (FIG. 2), the flow rate of the liquid is continuously reduced by the plunger 10 as it moves into the central opening 18, because, as the plunger 10 moves down, the surface 23 of the small ring-shaped gap 24, which forms the boundary of the central opening 18 and is slanted at the angle (), becomes continuously smaller. As a result, the filling operation is completed gently and without splashing.

(22) Thus, while there have shown and described and pointed out fundamental novel features of the invention as applied to a preferred embodiment thereof, it will be understood that various omissions and substitutions and changes in the form and details of the devices illustrated, and in their operation, may be made by those skilled in the art without departing from the spirit of the invention. For example, it is expressly intended that all combinations of those elements and/or method steps which perform substantially the same function in substantially the same way to achieve the same results are within the scope of the invention. Moreover, it should be recognized that structures and/or elements and/or method steps shown and/or described in connection with any disclosed form or embodiment of the invention may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design choice. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.