The invention relates to a device for filling liquid or flowable contents into packaging, comprising: a tank for the contents to be filled, a filling device with a filling valve, wherein the filling valve has a variable flow cross-section and is adjustable between an open position and a fully closed position; a line connecting the tank to the filling device; a throttle valve arranged in the line between the tank and the filling device, wherein the throttle valve has a variable flow cross-section and is adjustable between a first open position and a second open position; and a control device for controlling the filling valve and the throttle valve.
The invention also relates to a method for filling liquid or flowable contents into packaging, comprising the following steps: a) providing a device for filling liquid contents into packaging having a filling valve and having a throttle valve, b) opening the filling valve, c) enlarging the flow cross-section of the throttle valve from a first cross-sectional area to a second cross-sectional area, d) reducing the flow cross-section of the throttle valve from a second cross-sectional area to a first cross-sectional area, and e) closing the filling valve.
The filling of liquid contents into packaging is a problem that arises in the field of packaging technology, for example in regard to foodstuffs. There are therefore numerous possibilities known for filling liquid or flowable products into the designated packaging.
The liquid or flowable products may be, for example, foodstuffs such as milk, fruit juice, sauces or yoghurt. As packaging, for example, composite packaging with several thin layers of paper, cardboard, plastic or metal can be used.
The filling is often carried out by a device having a tank for the contents to be filled and a filling device with a filling valve. A line connects the tank to the filling device. Often the tank is located higher than the filling device, so that the line is inclined, and gravity can be used for filling. When the filling valve is opened, contents from the filling device can flow into the packaging until the filling valve is closed again. The filling valve should be completely closable so that a good seal is achieved, and no contents accidentally flow out of the filling device. In particular, for reasons of hygiene, it must be ensured that, when the packaging to be filled is changed, no contents flow out of the filling device and thereby contaminate the filling system.
In addition to the filling valve, further valves are provided in many known devices, such as throttle valves. Throttle valves are used in particular to set and adjust the flow rate. Such a device is known from EP 2 199 249 B1. With regard to the throttle valve, the aforementioned patent proposes that the throttle valve (in the aforementioned patent: “second valve device”) completely interrupts the fluid flow during a filling process at least temporarily.
An important step in the filling of the packaging is to fill the flowable or liquid products as quickly as possible into the packaging in order that fast timing and thus high volumes can be achieved. Despite the high flow rate, however, the filling should be done largely without spattering and foaming in order to meet the hygienic requirements and to avoid contamination on the packaging or the filling machine. Although the method proposed in EP 2 199 249 B1 makes it possible to achieve a clean stall without dripping when closing the filling valve, in practice it has proved disadvantageous for other reasons. This is because the complete shut-off of the throttle valve with the filling valve still open leads to air inclusions in the product stream. This is due, on the one hand, to the fact that the product stream flowing out of the filling device causes a negative pressure in the section between the blocked throttle valve and the open filling valve, which causes air to be drawn into the device through the filling valve. The air flows counter to the flow direction of the product stream and into the device and therefore causes undesirable air inclusions in the product stream. This leads to stalls and to increased formation of splashes when filling the contents in the packaging. The negative pressure also causes air to leach out (“outgassing”) of the contents to be filled (e.g. milk), leading to further air inclusions. Hygienic disadvantages are one consequence of this, for example the contamination of the filling system. The high hygienic requirements, which are to be complied with in particular with the sterile filling of foodstuffs, can hardly be fulfilled in this way.
The invention is therefore based on the problem of redesigning and further developing the aforementioned device previously described in more detail, such that even at high fill rates, a filling is largely possible without splashing and foaming.
This problem is solved by a device according to the preamble of Claim 1 in that the control device and/or the throttle valve are configured such that the throttle valve is at least partially open throughout the entire filling time.
The device is a device for filling liquid or flowable contents into packaging. The liquid or flowable contents may be, for example, foodstuffs such as milk, fruit juice, sauces or yoghurt. As packaging, for example, composite packaging with several thin layers of paper, cardboard, plastic or metal can be used. The device initially comprises a tank for the contents to be filled and a filling device with a filling valve. The tank is preferably arranged at least 10 cm above the filling device. The filling valve has a variable flow cross-section and is adjustable between an open position and a fully closed position. The flow cross-section of the filling valve can thus be reduced to “zero”. The apparatus further comprises a line connecting the tank to the filling device and a throttle valve arranged in the line between the tank and the filling device. The contents to be filled must therefore flow through a throttle valve on their way from the tank to the filling device and to the filling valve. It can be provided that the throttle valve is the only valve between the tank and the filling valve or alternatively that further valves are provided. The throttle valve has a variable flow cross-section and is adjustable between a first open position and a second open position. It can be provided that the throttle valve is not completely closable. The device finally comprises a control device for controlling the filling valve and the throttle valve. For this purpose, the control device is preferably connected to the filling valve and to the throttle valve.
According to the invention, it is provided that the control device and/or the throttle valve are configured such that the throttle valve is at least partially open throughout the entire filling time. The filling time refers to the period in which the liquid contents can exit from the filling valve, i.e. the period between the opening of the filling valve and the closing of the filling valve. According to the invention, no complete shut-off of the throttle valve should take place within this period. The flow cross-section of the throttle valve should therefore be at least partially open during the entire filling time. This can be achieved in different ways:
One advantage of the throttle valve being at least partially open during the entire filling time is that the pressure surge when opening and closing the filling valve is reduced. This reduces the risk of air inclusions due to air intake and/or outgassing and also reduces the risk of stalls. In addition, the pressure surge can expand against the tank, so that a definable state can be set in the product located in front of the filling valve and exactly the same starting conditions can be set before each filling cycle in the pipe space in front of the filling valve.
It can be provided that the control device and/or the throttle valve are configured such that the throttle valve is at least partially open continuously even outside the filling time.
According to one embodiment of the device, it is provided that the flow cross-section of the throttle valve is at least 3 mm2, in particular at least 10 mm2 throughout the entire filling time. By establishing a minimum size for the flow-through flow cross-section of the throttle valve, it is also possible to ensure that the throttle valve does not completely interrupt the flow, thus avoiding the associated disadvantages, even in the case of contents to be filled having a high viscosity and/or lumpy constituents (for example fruit pulp). In addition, the outgassing of the contents to be filled can be ruled out.
A development of the device provides a shut-off valve, which is arranged in the line between the tank and the filling device. By providing a shut-off valve in the line in addition to the throttle valve, the filling of the packaging can be controlled even more flexibly. In addition, a stepwise and particularly strong throttling can be achieved by the additional valve without stalling.
For this development, it is further proposed that the control device and/or the shut-off valve are configured such that the shut-off valve is at least partially open throughout the entire filling time. As has already been explained for the throttle valve, according to this further embodiment no complete shut-off of the shut-off valve should take place during the filling time. The flow cross-section of the shut-off valve should therefore be at least partially open during the entire filling time. This can be achieved in different ways:
It can be provided that the control device and/or the shut-off valve are configured in such a way that the shut-off valve is at least partially open continuously even outside the filling time.
According to a development of the device, it is provided that the flow cross-section of the shut-off valve is at least 1 mm2, in particular at least 3 mm2, throughout the entire filling time. By establishing a minimum size for the flow-through flow cross-section of the shut-off valve, it is also possible to ensure that the shut-off valve does not completely interrupt the flow, thus avoiding the associated disadvantages, even in the case of contents to be filled having a high viscosity and/or lumpy constituents (for example fruit pulp).
The device can be supplemented according to a further embodiment by a flow meter, which is arranged in the line between the tank and the filling device. The flow meter is used to measure the volume flow. The collected data may be used to control the filling valve and other components (e.g. the throttle valve). In particular, the flow meter allows the filling of different filling volumes on the same filling machine. The flow meter may be, for example, a mechanical flow meter, a magnetic-inductive flowmeter, or a mass flow meter (e.g. Coriolis mass flowmeter).
According to a further embodiment of the device, it is provided that the throttle valve and/or the shut-off valve has an actuator for setting the flow cross-section. The actuator serves to vary the valve position and may include, for example, an actuation unit (e.g. pneumatic) and a membrane (e.g. plastic).
For this purpose, it is further proposed that the throttle valve and/or the shut-off valve have a channel whose flow cross-section can be varied by the actuator, in particular can be completely shut off. The variability of the cross-sectional area of the flow cross-section can be achieved, for example, by the fact that the geometry of a channel wall is variable, for example, by a membrane or by another displaceable closure member.
Alternatively or additionally, it can be provided that the throttle valve and/or the shut-off valve have a passage opening whose flow cross-section through the actuator is not variable, in particular cannot be completely shut off. This can be achieved in that the passage opening is arranged outside the range of the movable parts of the actuator. The passage opening can therefore be regarded as a “bypass”, which bridges the areas of the valve that can be shut off.
According to a further embodiment of the device it is provided that the filling valve is segmentless or segmented. A segmentless filling valve is understood to mean a valve which forms only a single filling jet, while a segmented filling valve is understood to mean a valve which divides the filling jet into a plurality of partial flows (e.g. to change the jet shape). For segmentless filling valves, special attention must be paid to a clean start-up and closure (shut off) of the filling jet, which is achieved in a particularly suitable manner by the device described above.
The problem described above is also solved by a method for filling liquid or flowable contents into packaging. The method comprises the following steps: a) providing a device for filling liquid contents into packaging having a filling valve and with a throttle valve, b) opening the filling valve, c) enlarging the flow cross-section of the throttle valve from a first cross-sectional area to a second cross-sectional area, d) reducing the flow cross-section of the throttle valve from a second cross-sectional area to a first cross-sectional area; and e) closing the filling valve.
The method is characterised in that the throttle valve is at least partially open throughout the entire filling time. As has already been described in connection with the device, no complete shut-off of the throttle valve should take place within the filling time. This results in that the contents to be filled can and, if there are no other obstacles, will flow through the throttle valve throughout the entire filling time. The flow cross-section of the throttle valve should therefore be at least partially open during the entire filling time. This can be achieved, for example, in the two manners already described above (“control technology solution”; “mechanical solution”). It can be provided that the control device and/or the throttle valve are configured such that the throttle valve is at least partially open continuously even outside the filling time.
According to one embodiment of the method, it is provided that in step a) a device according to any one of Claims 1 to 10 is provided. By means of the above-described configuration of the control device and/or of the throttle valve, the device described above is suitable in all the illustrated embodiments for carrying out the method in a particular way.
According to a further embodiment the method, it is provided that steps b) to e) take place in the sequence b-c-d-e. It can therefore be provided that initially an opening of the filling valve takes place (step b), before the flow cross-section of the throttle valve increases (step c) and is reduced again (step d). Only then should the filling valve be closed again (step e). In this way, the filling time is divided into several phases with different fill rates: At the beginning of the filling time a low fill rate is used for filling (flow cross-section of the throttle valve small), later an increased fill rate is used for filling (flow cross-section of the throttle valve larger) and in the last phase a filling time is used with a low fill rate for filling again (flow cross-section of the throttle valve small). The reduction of the fill rate at the beginning of the filling time has the advantage that the filling jet starts more effectively and smoothly, and generates less momentum, in particular less foam, in the packaging. The reduction of the fill rate towards the end of the filling time has the advantage that fewer spatters occur.
According to a further embodiment of the method, the method can be supplemented by the following steps: f) enlarging the flow cross-section of the shut-off valve from a first cross-sectional area to a second cross-sectional area, and g) reducing the flow cross-section of the shut-off valve from a second cross-sectional area to a first cross-sectional area, wherein the shut-off valve is at least partially open throughout the entire filling time. As has already been described in connection with the throttle valve, the shut-off valve can also enable changing flow cross-sections and fill rates.
For this purpose, it is further proposed that step f) takes place before steps b) to e). In other words, the opening of the shut-off valve should in particular already take place before the opening of the filling valve. This has the effect that the filling can take place directly when the filling valve opens with the fill rate made possible by the throttle valve. Another advantage is that possibly trapped air bubbles can rise and thus venting is achieved.
Alternatively or additionally, it is finally provided that step g) takes place after step d) and before step e). The flow cross-section of the shut-off valve should therefore be reduced before the filling valve is completely closed again. This results in a reduction in the filling rate in the last phase of the filling time. Another advantage is that a smooth closing and good shut-off of the filling jet is achieved.
The invention will subsequently be explained in more detail with reference to a drawing showing only a preferred design example. In the drawings:
The time profiles shown in
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In the first valve position (
The valve 13 shown in
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Number | Date | Country | Kind |
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10 2017 000 970.8 | Feb 2017 | DE | national |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2018/051195 | 1/18/2018 | WO | 00 |