EP2748104B2 - Vacuum device for plants for the processing of containers, and method for controlling a vacuum device - Google Patents

Description

The invention relates to a vacuum device according to the preamble of patent claim 1, to a system for treating containers according to the preamble 7 and to a method for controlling a vacuum device of the claim according to the preamble of claim 8. The preamble of claims 1, 7 and 8 is for example from the EP 1 595 794 A1 known.

For example, in plants for filling containers with a liquid product, e.g. in Behälterabfüllanlagen, in certain filling process vacuum or vacuum is required and used to remove ambient air and associated with the oxygen in the ambient air from the containers to be filled, in one of the actual filling phase preceding single or multi-stage pre-treatment phase.

Known, in particular also used in the beverage industry vacuum devices have in common that they are always equipped with a vacuum source formed by a single vacuum source, the vacuum pump in question in terms of their vacuum performance and their electrical power, etc. to those for the respective system in normal operation or but also in maximum operation required vacuum or suction power is adjusted. Changes or fluctuations in the currently required vacuum or suction power can then be considered by changing the speed of the vacuum pump only within certain limits.

This procedure has the consequence that the manufacturers of such systems for different vacuum devices of different vacuum power provide different, adapted to the respective required vacuum power vacuum pumps.

The disadvantage is u.a. an increased effort for storage and stockpiling of different vacuum pumps and their spare parts, associated increased costs and the fact that a change in the vacuum and suction power of the vacuum device in question only to a limited extent and then only possible that in certain operating conditions only an inadequate efficiency for the single vacuum pump is accepted.

The object of the invention is to provide a vacuum device which avoids the aforementioned disadvantages and allows for high reliability adjustment of the vacuum device provided or ready to be provided vacuum or suction in a wide range and while maintaining the best possible efficiency.

To solve this problem, a vacuum device according to the patent claim 1 is formed. A system for treating containers is the subject of claim 7. A method for controlling a vacuum device is the subject of claim 8.

According to a first aspect of the invention, the vacuum device consists of at least two vacuum pumps designed for parallel operation, preferably of more than two vacuum pumps designed for parallel operation, these vacuum pumps preferably being of identical construction and power. Another aspect of the invention is that the total vacuum or suction power of the vacuum device is controlled by the speed and the number of activated vacuum pumps.

• verminderter Energie- und Stromverbrauch,
• Reduzierung der Lagerhaltung und Lagerhaltungskosten, insbesondere auch von Ersatzteilen,
• kürzere Lieferzeit von Ersatzteilen,
• teilredundante Systeme,
• vereinfachte Wartung, sowie
• Wasserersparnis durch gemeinsame Sperrwasseraufbereitung für sämtliche Vakuumpumpen.

Major advantages of the invention include

• reduced energy and electricity consumption,
• Reduction of warehousing and storage costs, especially of spare parts,
• shorter delivery time for spare parts,
• partially redundant systems,
• simplified maintenance, as well
• Water savings through joint water treatment for all vacuum pumps.

Furthermore, the invention offers the possibility to convert existing vacuum devices accordingly.

The expression "essentially" or "approximately" in the sense of the invention means deviations from the exact value by +/- 10%, preferably by +/- 5% and / or deviations in the form of changes that are insignificant for the function.

Further developments, advantages and applications of the invention will become apparent from the following description of exemplary embodiments and from the figures.

"Bulk performance" in the sense of the invention means e.g. Capacity of the container filling machine per unit of time measured in liters.

"Container" are in the context of the invention in particular cans, bottles, tubes, pouches, each made of metal, glass and / or plastic, but also other packaging materials that are suitable for filling liquid or viscous products.

Fig. 1

in einem Funktions- bzw. Blockdiagramm eine Behälterbehandlungsmaschine zusammen mit einer Vakuumeinrichtung;

Fig. 2

in einem Diagramm die elektrische Leistung der Vakuumeinrichtung in Abhängigkeit von der Saugleistung bei einem vorgegebenen Unterdruck.

The invention will be explained in more detail below with reference to the figures of an embodiment. Show it:

Fig. 1

in a functional block diagram, a container treatment machine together with a vacuum device;

Fig. 2

in a diagram, the electrical power of the vacuum device as a function of the suction power at a predetermined negative pressure.

In the FIG. 1 1 is a plant for treating containers 2, for example in the form of bottles. The plant 1 comprises at least one device or machine, for example a filling machine, in which the containers 2 and / or device areas are subjected to a vacuum or to a negative pressure, for example with a negative pressure in the range from 80 mbar to 100 mbar. The containers 2 are fed to the system 1 at a container inlet 1.1 and discharged from the system 1 at a container outlet 1.2.

In order to generate the necessary negative pressure or vacuum, a central vacuum device 3 is provided for the system 1, which has a multiplicity of electrically operated vacuum pumps 4.1-4.3. In the illustrated embodiment, the vacuum device 3 has a total of three vacuum pumps 4.1 - 4.3, the vacuum or suction power can be individually controlled within certain limits by changing the pump speed or regulated. For this purpose, the electrical control of the drive motor of the respective vacuum pump 4.1 - 4.3 is frequency-controlled via a frequency control device, for example in a frequency range between 40 Hz and 60 Hz.

With 5 is in the FIG. 1 a control and regulating electronics or a machine control referred to, for example, is formed by the process computer of Appendix 1 or provided in addition to this process computer and, among other things, depending on process parameters in the manner described in more detail below, the circuit and control or regulation the vacuum pump 4.1 - 4.3 takes place.

The process parameters can for example be retrievable from a memory of the control and regulating electronics and / or be input via an input 6 in the control electronics.

In a system for filling the containers 2, wherein the containers, for example, before the actual filling one or more times applied with vacuum and then with an inert gas, such as CO2 gas, rinsed, it may be in the process parameters to product-specific parameters, the container size, the filling temperature, etc. act.

With these process parameters, the required number of pumps is for example tabulated and entered or read at the beginning of production in the machine control 5 for a special treatment method and for a temperature for the closed circuit of the vacuum pumps 4.1 - 4.3, so that with this number of pumps (start condition) the production Appendix 1 can be started.

In the tables below, the number of required vacuum pumps 4.1-4.3 depending on the suction power in m ³ / h are reproduced for three different treatment methods carried out with the system 1, ie for three different filling methods and for different temperatures of the sealing water of the vacuum pumps.

As mentioned above, the suction power of the vacuum pumps 4.1 - 4.3 is controlled or regulated by their speed. In this case, it is necessary, depending on the type of pump used, to set the speed of the vacuum pump 4.1-4.3 so that it makes economic sense, i. can be operated with the best possible efficiency. Taking into account the frequency of the operating or supply voltage, the power consumption, the mechanical efficiency, the hydraulic efficiency and the electrical efficiency, a pump characteristic can be determined for each type of pump, which reproduces the electrical connection power, ie the electrical power requirement as a function of the vacuum or suction power , In the event that other parameters, such as the barrier water temperature have a significant influence on the electrical power requirement of the respective vacuum pump 4.1 - 4.3, these are also taken into account in the pump characteristic or parameter-specific pump characteristics are determined.

In the applicant's home, different specific power requirements were determined during tests on a vacuum pump at different operating states, these values ranging from 27 m ³ / kW up to 40 m ³ / kW. These values make it clear that there is considerable potential for optimization here.

Taking into account the pump characteristic, preferably also taking into account the overall efficiency of the vacuum device 3 and the vacuum-leading portion of the system 1, which is in the FIG. 2 represented overall characteristic curve 7, which at a predetermined, generated by the vacuum device 3 constant negative pressure, ie in the illustrated embodiment at a negative pressure of 80 mbar the electrical power requirement in kW as a function of the suction power in m ³ / h. With this overall characteristic curve 7, which is stored in the memory of the machine control 5, the further regulation and control of the vacuum device 3 then take place during the ongoing operation of the system 1, for example on the basis of the start condition defined on the basis of the above table.

An essential part of the overall characteristic curve 7 are the switching points specified there with SP1 and SP2, at which the switching of the number of vacuum pumps 4.1-4.3 to a higher or lower number of vacuum pumps, for example switching from a vacuum pump to two parallel-operated vacuum pumps at the switching point SP1 or switching from two parallel operated vacuum pumps to three parallel operated vacuum pumps at the switching point SP2 and vice versa. As a criterion for the switching by the machine control 5, for example, the electric power supplied to the vacuum device, which is monitored by the machine control.

Like the diagram of FIG. 2 It can be seen, there would be the possibility in principle with only a single vacuum pump 4.1 - 4.2 to achieve beyond the switching point SP1 higher suction power, but with a significant deterioration in efficiency and thus with an increased electrical power consumption, as shown in the diagram with the operating point 7.1 is indicated. In this case, the operating point is a possible operating point in the operation of a single vacuum pump 4.1-4.3, wherein also for this operating point of a single vacuum pump suction power and associated power consumption are known. Like from the FIG. 2 can be seen, is at the, associated with the operating point 7.1 suction power of the power requirement of a single vacuum pump significantly above the power demand of two parallel operated vacuum pumps.

In an analogous manner, with only two vacuum pumps operated in parallel, the suction power could be increased beyond the suction point SP2, but again with a significantly reduced efficiency and with a significant increase in the electrical power requirement, as indicated in the diagram with the operating points 7.2.

Like in the FIG. 2 Furthermore, the pumps are operated in the different operating states with different frequencies and thus with different pump speeds, namely in the operating state with only one activated vacuum pump 4.1 - 4.3 with a frequency between 40 and 58 Hz, in the operating state with two activated vacuum pumps 4.1 - 4.3 with a frequency between 40 and 52 Hz and in the operating state with three activated pumps with a frequency between 40 and 60 Hz.

The in the FIG. 2 reproduced overall characteristic takes into account a sealing water temperature of the vacuum pump 4.1 - 4.3, for example, 25 ° C. If the trap water temperature has a greater influence on the pump characteristic or on the efficiency of the vacuum pumps 4.1 - 4.3, this results for each trap water temperature different overall characteristics 7, which are then taken into account for the control and regulation of the vacuum pumps 4.1 - 4.3 during the ongoing process.

For this purpose, the barrier water temperature is preferably continuously measured during operation of the system 1 and transmitted to the machine control 5, the machine controller 5 depending on the measured barrier water temperature, the respective associated overall characteristic curve 7 is used to control or regulate the system.

The overall characteristic curve 7 shown as an example also assumes that the vacuum pumps 4.1-4.3 operating in parallel are each operated at the same frequency of the supply voltage. Although this is an easy-to-implement solution, operation of the vacuum pumps 4.1 - 4.3 operating in parallel with the same frequency of the supply voltage is generally not mandatory. In the context of the present invention, it is likewise provided that the individual, parallel-operated vacuum pumps 4.1-4.3 are also operated with different mains frequencies, which opens up the possibility of increasing the efficiency of the overall system, at least for some vacuum powers.

In order to ensure a proper supply of the plant 1 with the vacuum and in particular also a proper vacuum treatment of the container 2, it is necessary that in the corresponding, vacuum lines and / or connections a predetermined desired negative pressure, for example the negative pressure of 80 mbar - 100 mbar, which is then identical to the negative pressure at the suction side of the activated vacuum pumps 4.1 - 4.3. To monitor the negative pressure is in the FIG. 1 a pressure sensor 8 in a vacuum line between the vacuum device 3 and the system 1 play. Depending on the electrical measurement signal generated by the pressure sensor 8, at least the vacuum power of one of the activated vacuum pumps 4.1-4.3 is changed via appropriate adjustment of the frequency and thus the pump speed via the machine controller 5 so that the negative pressure provided by the vacuum device 3 is the target negative pressure equivalent.

If, for example, the next upper switching point SP1 or SP2 is reached in this regulation of the pump speed, then the machine control 5 switches according to the overall characteristic curve 7 to the next higher number of parallel-operated vacuum pumps 4.1-4.3. Conversely, if a reduction of the suction power of the vacuum unit 3 and thus a reduction of the pump speed is required, then the machine control 5 switches to the next lower number of activated vacuum pumps 4.1 - 4.3 when reaching the switching point SP1 or SP2.

With 9 is in the FIG. 1 a common for all vacuum pumps 4.1 - 4.3 of the vacuum device 3 means for providing and / or treatment of sealing water, which is part of a through the vacuum pumps 4.1 - 4.3 water cycle and including a device for cooling the sealing water and connections for venting, for supplying Has fresh water and for discharging wastewater.

Taking into account the power consumption of the vacuum unit 3 and the overall characteristic curve 7, a functional and fault monitoring of the overall system is furthermore possible. It is known to the machine control 5 which number of vacuum pumps 4.1-4.3 must be operated at a given operating state of the system with a predetermined frequency of the supply voltage or which desired energy consumption results from the respective operating state. The corresponding values, ie the number of activated vacuum pumps 4.1 - 4.3, the frequency of the supply voltage for these pumps and thus also the energy consumption for maintaining the desired negative pressure by more than a specific amount, which is defined by a predetermined permissible tolerance range, deviate from From the setpoint values, there is a defect in the vacuum device 3 or in the system 1, for example in the form of a larger leak. In this case, a warning or warning signal or a warning or information message is issued by the machine control 5 or by another monitoring unit. In the case of significant deviations from the setpoint values, the machine control unit causes, for example, a shutdown and stopping of the system 1.

Only in a few operating states of the system 1 it is necessary that all vacuum pumps 4.1 - 4.3 of the vacuum device 3 are activated simultaneously. Rather, during a large part of the operating time of the vacuum system 3, only a subset of the existing vacuum pumps 4.1 - 4.3 in use. To the operating times and thus u.a. the intervals for inspections, maintenance, repairs, etc. for all vacuum pumps 4.1 - 4.3 to keep as equal as possible, the machine control 5 is further designed to record the respective operating time or operating hours of each vacuum pump 4.1 - 4.3 and to store the corresponding data. This results in different methods for maintaining the same operating times for all vacuum pumps 4.1 - 4.3.

According to a first method, both at the beginning of the process and during the ongoing process of the machine controller 5 always those vacuum 4.1 - 4.3 preferably activated, currently have the lowest operating times, so that a uniform use of all vacuum pumps 4.1 - 4.3 takes place and for all vacuum pumps the respective Maintenance is due at the same time.

According to another method, the vacuum pumps 4.1-4.3 to be activated are each selected so that the maintenance for a subset of the vacuum pumps 4.1-4.3 is then incurred, even if the plant 1 and / or its components must be maintained, so that inter alia, the number of production interruptions and / or inserts for maintenance personnel and thus also the associated costs are significantly reduced.

After a further operating method that vacuum pump 4.1 - 4.3 is blocked, in which, for example, due to their operating hours and / or their condition maintenance is mandatory. The operation of the vacuum device 3 is then carried out exclusively with the remaining, not locked vacuum pumps 4.1 - 4.3. The maintenance and / or repair of the locked vacuum pump are carried out during operation.

Of course, the aforementioned operating methods for the operation of the vacuum pumps 4.1 - 4.3 can also be combined.

The invention has been described above by means of exemplary embodiments. It is understood that changes and modifications are possible without thereby departing from the scope of the invention as defined by the following claims. Thus, it was assumed above that the vacuum device 3 has a total of three vacuum pumps 4.1 - 4.3. The number of these pumps may also differ, but in any case is greater than one.

LIST OF REFERENCE NUMBERS

1

Plant for the treatment of containers

1.1

container inlet

1.2

container outlet

2

container

3

vacuum equipment

4.1 - 4.3

vacuum pump

5

machine control

6

Input of the machine control 5

7

Overall characteristic

7.1, 7.2

working

8th

pressure sensor

9

Device for providing and / or treating blocked water

SP1, SP2

switching point

Claims (14)

1. Vacuum device for creating negative pressure in plants for the processing of containers (2), in particular in systems for the filling of containers (2) with a liquid filling product, with a vacuum source, of which the vacuum capacity and/or suction capacity is controllable and/or regulatable, wherein the vacuum source of the vacuum device (3) is formed by at least two electrically driven vacuum pumps (4.1 - 4.3), configured for parallel operation, and wherein the total vacuum capacity or suction capacity of the vacuum device (3) is controllable by the number of vacuum pumps (4.1 - 4.3) activated in each case, by means of a controlling and regulating unit (5), characterised in that the controlling and regulating unit (5) is configured for controlling and/or regulating the vacuum capacity and/or suction capacity of the vacuum pumps (4.1 - 4.3) and for switching the vacuum pumps (4.1 - 4.3) on and off, taking into account a total characteristic curve (7) of the vacuum device (3), which reproduces the electrical power for the drive of the vacuum pumps (4.1 - 4.3) which is required for a total vacuum capacity and/or suction capacity of the vacuum device (3), and specifically by taking account of the pump characteristic curves of the vacuum pumps (4.1 - 4.3) and of an optimum degree of efficiency for the vacuum pumps (4.1 - 4.3), deriving in each case from their pump characteristic curve, wherein the pump characteristic curves of the vacuum pumps (4.1 - 4.3) reproduce their vacuum capacity and suction capacity as a function of the electrical power requirement.
2. Vacuum device according to claim 1, characterised in that the vacuum capacity or suction capacity of each vacuum pump (4.1 - 4.3) can be controlled or regulated, preferably by changing the frequency of the supply voltage driving the vacuum pumps (4.1 - 4.3), for example by a change of the frequency in a frequency range between 40 and 60 Hz.
3. Vacuum device according to claim 1 or 2, characterised in that the control and regulating unit (5) is configured for a controlling and/or regulating of the total vacuum capacity or suction capacity of the vacuum device (3) as a function of process parameters of the plant (1) for the processing of the containers (2), wherein the process parameters take account, for example, of the type of the processing method carried out by the plant (1) and/or the container sizes and/or container shapes and/or the filling capacity of the plant (1) and/or of a container filling machine.
4. Vacuum device according to one of the preceding claims, characterised in that the total characteristic curve (7) comprises switching points (SP1, SP2), at which switchover of the vacuum device (3) takes place from a number of activated vacuum pumps (4.1 - 4.3) to a next higher or lower number of activated vacuum pumps (4.1 - 4.3).
5. Vacuum device according to one of the preceding claims, characterised in that the vacuum pumps (4.1 - 4.3) are in each case of the same structural design.
6. Vacuum device according to one of the preceding claims, characterised in that for all the vacuum pumps (4.1 - 4.3) a common device (9) is provided for the preparation and/or provision of seal water.
7. Plant for the processing of containers (2), in particular for the filling of containers (2) with a liquid filling product, with a vacuum device (3) for imposing a vacuum or negative pressure on the containers (2) and/or areas of the plant (1), characterised in that the vacuum device (3) is configured in accordance with one of the preceding claims.
8. Method for controlling a vacuum device (3) for plants (1) for the processing of containers (2), in particular for plants for the filling of containers (2) with a liquid filling product, wherein a total vacuum capacity or suction capacity of the vacuum device (3) is controllable or regulatable, wherein the vacuum device (3) comprises at least two vacuum pumps (4.1 - 4.3) configured for parallel operation, and wherein, for the controlling and/or regulating of the total vacuum capacity or suction capacity of the vacuum device (3), the vacuum capacity or suction capacity of the vacuum pumps (4.1 - 4.3) is controlled and/or regulated, and/or the number of the activated vacuum pumps (4.1 - 4.3) is changed by switching the vacuum pumps (4.1 - 4.3) on and off, characterised in that the controlling and/or regulating of the vacuum capacity or suction capacity of the vacuum pumps (4.1 - 4.3) and the switching on and off of vacuum pumps (4.1 - 4.3) takes place by taking account of a total characteristic curve (7) of the vacuum device (3), which reproduces the electrical power required for the drive of the vacuum pumps (4.1 - 4.3) required for a total vacuum capacity or suction capacity of the vacuum device (3), and specifically by taking account of the pump characteristic curves of the vacuum pumps (4.1 - 4.3) and of an optimum degree of efficiency for the vacuum pumps (4.1 - 4.3), deriving in each case from their pump characteristic curve, wherein the pump characteristic curves of the vacuum pumps (4.1 - 4.3) reproduce their vacuum capacity and suction capacity as a function of the electrical power requirement.
9. Method according to claim 8, characterised in that, at the beginning of a method carried out with the plant (1) for the processing of the containers (2), taking account at least of the processing method and the total vacuum capacity or suction capacity of the vacuum device (3) thereby required, the number of the vacuum pumps (4.1 - 4.3) to be activated is determined, and these are activated.
10. Method according to one of claims 8 or 9, characterised in that the controlling and/or regulating of the total vacuum capacity or suction capacity of the vacuum device (3) is carried out as a function of process parameters of the plant (1) for the processing of the containers (2), wherein the process parameters take account, for example, of the type of the processing method carried out by the plant (1) and/or the container sizes and/or container shapes and/or the filling capacity of the plant (1) and/or of a container filling machine.
11. Method according to one of claims 8 to 10, characterised in that the switchover of the vacuum device (3) from a number of activated vacuum pumps (4.1 - 4.3) to a next higher or lower number of activated vacuum pumps (4.1 - 4.3) takes place at switching points (SP1, SP2) of the total characteristic curve (7).
12. Method according to one of claims 8 to 11, characterised in that, in order to obtain equal processing times or essentially equal processing times, those vacuum pumps (4.1 - 4.3) are activated which currently present the lowest operating times.
13. Method according to one of claims 8 to 12, characterised in that the vacuum pumps (4.1 - 4.3) are in each case selected in such a way that the maintenance of a part quantity of the vacuum pumps (4.1 - 4.3) takes place when the plant (1) or components of this plant must be maintained.
14. Method according to one of claims 8 to 13, characterised in that the maintenance and/or repair of a vacuum pump (4.1 - 4.3) is carried out after it has been stopped while the other vacuum pumps (4.1 -4.3) in the vacuum unit (3) are still running.

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