EP3609792B1 - Method for regulating the heat output of shrink-wrapping apparatuses and corresponding apparatus - Google Patents

Method for regulating the heat output of shrink-wrapping apparatuses and corresponding apparatus Download PDF

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Publication number
EP3609792B1
EP3609792B1 EP18717574.0A EP18717574A EP3609792B1 EP 3609792 B1 EP3609792 B1 EP 3609792B1 EP 18717574 A EP18717574 A EP 18717574A EP 3609792 B1 EP3609792 B1 EP 3609792B1
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EP
European Patent Office
Prior art keywords
heating
heating devices
operating mode
temperature
active
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Active
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EP18717574.0A
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German (de)
French (fr)
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EP3609792A1 (en
Inventor
Herbert Braam
Stefan Skodek
Heiko Bartholemy
Holger Kamps
Tobias Kersten
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KHS GmbH
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KHS GmbH
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65B—MACHINES, APPARATUS OR DEVICES FOR, OR METHODS OF, PACKAGING ARTICLES OR MATERIALS; UNPACKING
    • B65B53/00—Shrinking wrappers, containers, or container covers during or after packaging
    • B65B53/02—Shrinking wrappers, containers, or container covers during or after packaging by heat
    • B65B53/06—Shrinking wrappers, containers, or container covers during or after packaging by heat supplied by gases, e.g. hot-air jets
    • B65B53/063—Tunnels
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65B—MACHINES, APPARATUS OR DEVICES FOR, OR METHODS OF, PACKAGING ARTICLES OR MATERIALS; UNPACKING
    • B65B57/00—Automatic control, checking, warning, or safety devices
    • B65B57/10—Automatic control, checking, warning, or safety devices responsive to absence, presence, abnormal feed, or misplacement of articles or materials to be packaged
    • B65B57/16—Automatic control, checking, warning, or safety devices responsive to absence, presence, abnormal feed, or misplacement of articles or materials to be packaged and operating to stop, or to control the speed of, the machine as a whole

Definitions

  • the invention relates to a method and a device for shrinking a flat material onto a group of individual packagings to form bundles.
  • a shrinking device following the packaging machine, a solid or fixed packaging unit or a container is formed from each packaging group as it is conveyed through by shrinking the shrink film under the action of heat.
  • the heat within the shrinking device can be generated, for example, by electrical heating devices.
  • the shrinking device can, for example, comprise a plurality of heating zones following one another in the transport direction of the individual packs.
  • shrink devices with electrical heating devices which have a relatively low basic heating load, for example a basic heating load of 12-15 kW per heating zone.
  • a heating device is provided for each heating zone, which is preferably switched on and off together with the main switch of the shrink tunnel. This heating device providing the basic heating load is therefore constantly activated.
  • the pamphlet DE 10 2010 020 957 A1 discloses a shrink tunnel for applying shrink films to packaging material in order to thereby form a packaging unit or a bundle. There are several along one transport direction Tunnel zones formed, each of which is assigned its own heating means. The heating means can be controlled between a basic heating load and a maximum heating output.
  • the pamphlet US 6,394,796 B1 discloses an oven for curing paints or coatings.
  • the oven has one or more temperature sensors to measure the temperature of the object to be hardened.
  • US 3678244 A also discloses an apparatus according to the preamble of claim 15.
  • the temperature control to the target temperature of the shrink tunnel is carried out by the additional heating devices of the respective heating zones, which for example have an output of up to 60 kW per heating zone.
  • These additional heating devices can be switched on and off via switching units.
  • the further heating devices are each operated jointly, that is to say also switched on or off jointly.
  • the desired target temperature of the shrink tunnel is reached very quickly after switching on the heating devices, which means that the heating devices that have just been switched on have to be switched off again after a short time in order to reach the target temperature of the shrink tunnel not to be exceeded in an impermissible manner.
  • the further heating devices In comparison to the low output of the heating device providing the basic heating load, the further heating devices have a high output, which means that the further heating devices are switched with a high switching frequency.
  • This high switching frequency is a major disadvantage, especially since it can result in high switching currents (including current peaks due to the switching process) of up to 100 amperes per supply line and the heating devices are exposed to high mechanical stress due to constant heating and cooling. Furthermore, due to the high switching currents in the known shrinking device, network disturbances, in particular voltage fluctuations, often occur in turn cause so-called flicker effects, i.e. fluctuations in brightness in light sources.
  • the object of the invention is to specify a method for operating a shrinking device which leads to a lower switching frequency and thus to lower mains voltage fluctuations.
  • a shrinking device is the subject of the independent claim 15.
  • the main advantage of the method according to the invention is that in the first operating mode, in which the system is operated with the basic heating load, the heating output (basic heating output) is not rigidly specified, but rather the number of heating devices active in the first operating mode and thus the amount of heating Basic heating power is determined based on operating parameters, so that a suitable choice of the basic heating power results in a reduced frequency of switching on and off the heating devices and thus reduced mains voltage fluctuations and reduced thermal loads on the heating devices.
  • the number of active heating devices in the first operating mode is dependent on the setpoint temperature in the heating zone.
  • the target temperature within the respective heating zone largely determines the heat requirement and thus the heating output to be provided.
  • Further operating parameters that can influence the number of active heating devices in the first operating mode are, for example, the ambient temperature, the average power requirement of the heating zone or the entire heating devices in a previous period, for example the past n minutes, where n can be a rational number , etc. This means that the basic heating output can be adapted to the current operating situation.
  • the number of active heating devices in the first operating mode is equal to or greater than two. In other words, not just a single heating device is used to generate the basic heating output, but at least two.
  • a basic heating load of more than 15KW is preferably provided by the at least two active heating devices.
  • the number of active heating devices in the second operating mode is one greater than the number of active heating devices in the first operating mode.
  • only one additional heating device is intermittently switched on in order to increase the temperature in the heating zone to the setpoint temperature. This allows the through the switching operations caused changes in performance and thus the voltage fluctuations in the electrical network are significantly reduced.
  • the number of active heating devices in the first operating mode is calculated by a control device, taking into account at least one operating parameter.
  • the basic heating output can be adjusted automatically.
  • the basic heating output is set manually by the operating personnel depending on the operating parameters.
  • the number of heating devices active in the first operating mode is calculated continuously or intermittently during operation of the device based on operating parameters. This means that the basic heating output can be continuously adapted to changes in the operating situation.
  • the number of heating devices active in the first operating mode is determined taking into account the temperature changes in the respective heating zone caused by the activation and / or deactivation of the respective heating devices. For example, the time profile of the temperature change after activating or deactivating a certain heating device can be determined and derived therefrom whether or not this heating device should be activated to provide the basic heating output.
  • the heating devices assigned to the respective heating zone can each have the same heating output or different heating output.
  • that heating device can be activated to provide the basic heating power, which as precisely as possible covers the power requirement that causes reduced switching activities in a certain operating situation (e.g. target temperature, ambient temperature, etc.).
  • the number of heating devices active in the first operating mode is reduced by one if, in the second operating mode, the measured actual temperature in the area of the heating zone exceeds the setpoint temperature by a predetermined temperature difference value for a predetermined period of time. This is an indication that the basic heating output has been selected too high and that this causes a high level of switching activity in the heating devices that are switched on intermittently.
  • the temperature difference value is in the range between 1 ° C and 5 ° C, in particular at 2 ° C, 3 ° C or 4 ° C.
  • the predefined period of time is in the range between 30 seconds and 3 minutes and in particular is 1 minute, 1.5 minutes or 2 minutes or more.
  • the number of heating devices active in the first operating mode is reduced by one if the ratio of the time period in which the device is in the second operating mode to the time period in which the device is in the first operating mode falls below a threshold value.
  • the duration ratio is determined, which indicates how long the heating zone is operated with basic heating power.
  • the basic heating output is reduced if the duration ratio indicates that the heating zone is only operated very briefly with a heating output above the basic heating output.
  • the ratio of the periods of time is determined over a number of switching cycles. In this way, an average value of the time duration ratio can be calculated. A decision on reducing the basic heating output can then be made based on the duration ratio.
  • the heating devices are activated and deactivated by switching means, the switching means preferably also including the monitor electrical load switched by them. This makes it possible, based on the switching means, to control the state of the heating devices, for example to recognize a failure due to the interruption of a heating conductor or a short circuit.
  • the heating devices are activated and deactivated by at least one switching device which is designed to switch the heating devices according to the principle of vibration packet control.
  • the switching device is designed to activate or deactivate the heating devices in zero crossings of the current or voltage profile. This largely avoids current and voltage transients and thus harmonics.
  • the heating zone is heated by activating, in particular by activating all heating devices with a delay.
  • the change in load can be distributed over time and thus the effects on the electrical network can be reduced.
  • the invention also relates to a device for shrinking a flat material onto a group of individual packagings.
  • the device comprises at least one heating zone having a plurality of electrical heating devices and a temperature sensor for determining the actual temperature in the area of the heating zone, a control device being provided which is used to receive information relating to the actual temperature in the area of the heating zone and to initiate a switchover of the Device is designed from a first operating mode to a second operating mode.
  • switching means are provided which interact with the control device in such a way that a change is made to a first operating mode by reducing the number of active heating devices to a predefined number of heating devices when the actual temperature in the area of the heating zone has exceeded a setpoint temperature, with the predefined number of heating devices was determined taking into account at least one operating parameter.
  • the switching means interact with the control device in such a way that from the first operating mode into one The second operating mode is switched over by increasing the number of active heating devices for regulating the actual temperature in the area of the heating zone to the setpoint temperature.
  • the reference numeral 1 shows a device for shrinking a flat material onto a group of individual packages.
  • Such devices 1 are also referred to as shrinking devices.
  • the device 1 comprises a conveyor 5, on which grouped individual packagings, for example bottles, cans or other packaging materials, are fed as packaging material groups wrapped in a flat material to a shrink tunnel 6.
  • the flat material can in particular be a film made of a plastic material, which contracts under the action of heat and thus combines the individual packagings to form a container.
  • the shrink tunnel 6 has a plurality of heating zones I, II, in each of which a plurality of electrical heating devices HR are provided for generating the heat required for shrinking the flat material.
  • the electrical heating devices HR can be any heating devices operated by electrical current, in particular resistance heaters with at least one heating coil.
  • a temperature sensor is provided to control the temperature within the respective heating zone I, II.
  • each heating zone I, II has at least one temperature sensor, by means of which the actual temperature in the area of this heating zone I, II is recorded. Based on the information obtained by this temperature sensor, it is possible to control and / or regulate the actual temperature within the heating zone I, II in such a way that it is regulated in the range of a target temperature ST.
  • This target temperature ST depends in particular on the material enveloping the packaging group, the conveying speed of the conveyor 5 or the dwell time of a packaging group in the respective heating zone I, II, etc.. This can for example be in the range between 150 ° C and 250 ° C, in particular between 170 ° C and 200 ° C.
  • the target temperature ST can be selected to be different for the different heating zones I, II.
  • the device 1 also has a control device 3.
  • the control device 3 is designed in particular to control the temperature within the respective heating zone I, II. This control can take place in particular by switching on or off the heating devices HR of the respective heating zone I, II.
  • the control device 3 is preferably connected to the temperature sensor provided in the heating zone I, II and receives information therefrom regarding the actual temperature within the heating zone I, II.
  • the control device 3 is designed to measure the actual temperature within the heating zone I, II to compare with a setpoint temperature ST and, based on this comparison result, the control of the heating devices HR, ie the intermittent activation and deactivation of the heating devices HR in the respective heating zone I, II to be carried out.
  • the control device 3 described has the function of a regulating device, so that the terms control and regulation in the context of the present application are always to be interpreted taking into account the respective passages of the description.
  • the heating devices HR are activated or deactivated (switched on or switched off) by switching means 4.
  • each heating device HR is assigned an independent switching means 4, so that each heating device HR can be activated or deactivated independently of the other heating devices.
  • the switching means 4 can in particular be formed by a semiconductor contactor.
  • the control of the device 1 is subsequently carried out based on the illustration in FIG Figure 3 explained in more detail.
  • the interior of the shrink tunnel 6 is first heated by the heating devices HR.
  • all heating devices HR are activated, so that heating zones I, II are heated up with maximum heating power.
  • the actual temperature within the respective heating zone I, II is detected by the temperature sensor and the heating zones I, II are operated with maximum heating power until the actual temperature has reached or exceeded the target temperature ST.
  • the number of active, ie switched on, heating devices HR is then reduced so that the respective heating zone I, II is heated with a basic heating load that is generated by a Number of active heating devices HR in the respective heating zone I, II is defined.
  • the number of active heating devices HR per heating zone I, II with the basic heating load is preferably at least two heating devices HR per heating zone I, II.
  • the regulation of the heating power per heating zone I, II and thus also the regulation of the actual temperature within the respective heating zone I, II to the desired target temperature ST is carried out by the control device 3, which sends control signals to the switching means 4 in order to activate or Deactivating the heating devices to achieve HR.
  • the heating devices HR are preferably always operated with a fixed electrical power, the amount of which cannot be changed. The heating devices HR are therefore only switched digitally (on / off).
  • the number of active heating devices HR required for the basic heating load is determined in advance as a function of operating parameters of the device 1.
  • the number of active heating devices HR to achieve the basic heating load can be determined, for example, based on empirical values of the operating personnel and set manually or by means of appropriate inputs on the machine control.
  • the control device 3 or a control computer connected to it can calculate the active heating devices HR required to achieve the basic heating load and for this calculated value to be used to operate the device 1 during the basic heating load.
  • operating parameters such as the target temperature ST, the ambient temperature, information regarding switching operations carried out in the past, etc. can be used for this calculation.
  • the number of active heating devices HR for achieving or continuously providing the basic heating load is preferably selected in such a way that the heating output achieved by these heating devices HR is less than the heating output required to achieve the setpoint temperature ST. This achieves that after the previously described heating process, after reaching or exceeding the target temperature ST by operating the device 1 at the basic heating load by deactivating at least one heating device HR compared to the heating process, the actual temperature in the heating zone I, II drops. In other words, after the heating process of the respective heating zone I, II, this heating zone I, II is initially operated with the basic heating load.
  • the described switchover takes place shortly before the actual temperature reaches the setpoint temperature ST, with the result that the actual temperature is reliably prevented from overshooting the setpoint temperature ST.
  • the number of active heating devices is increased, preferably by a single heating device HR (for the respective heating zone I, II) so that the The heating output now provided in the heating zone I, II is greater than the heat loss, so that the actual temperature in the heating zone I, II rises again.
  • a single heating device HR for the respective heating zone I, II
  • only one heating device HR is switched on and off intermittently so that the variation in the electrical power required for heating is minimized compared to the prior art.
  • the embodiment shown has a heating zone I, II four heating devices HR1, HR2, HR3, HR4, which can be activated independently of one another.
  • the heating devices HR1, HR2, HR3, HR4 bring about a temperature in the heating zone I, II according to the temperature diagram in FIG Fig. 3 .
  • the heating zone would first be heated by activating all four heating devices HR1, HR2, HR3, HR4. After the heating zone has been heated up, the heating device HR4 would be deactivated and the heating devices HR1, HR2, HR3 would remain activated. Since the heating power of the remaining three heating devices HR1, HR2, HR3 is less than that of the If there is any heat loss at the desired setpoint temperature, the actual temperature (after possibly existing reheating effects) would initially drop. If the actual temperature has fallen below a certain lower threshold value, the heating device HR4 would be activated again, which leads to a renewed increase in the actual temperature. The temperature control would then take place by intermittent activation / deactivation of the heating device HR4 with constant operation of the heating devices HR1, HR2, HR3. As a result, the load fluctuations in the electrical power grid and the switching frequency can be reduced considerably.
  • the device 1, preferably the control device 3 of the device 1, is designed to detect the temporal temperature changes caused by activating / deactivating the heating devices HR and, based on this, the number of heating devices HR required to operate the heating zones I, II with the basic heating load in this heating zone I, II to be determined.
  • the gradient of the temperature rise over time to reach the target temperature and / or the gradient of the temperature drop over time can be determined.
  • the number of active heating devices HR used for the basic heating load can be changed over time in order to adapt the basic heating load to current conditions (for example, a changed ambient temperature).
  • the number of active heating devices HR used for the basic heating load can be reduced by one if, when the heating output is increased compared to the basic heating load by switching on a further heating device HR (second operating mode), the measured actual temperature in the area of heating zones I, II exceeds the target temperature ST exceeds a predetermined temperature difference value for a predetermined period of time.
  • the basic heating load can be reduced if an overshoot in terms of temperature or time is reached in the temperature control.
  • the basic heating load can be reduced if the temperature difference value is in the range between 1 ° C and 5 ° C, in particular 2 ° C, 3 ° C or 4 ° C and / or the specified period of time is in the range between 30 seconds and 3 minutes, in particular 1 minute, 1.5 minutes or 2 minutes or more.
  • the ratio of a first time period during which a heating zone is operated above the basic heating load to a second time period during which the heating zone is operated below the basic heating load can be used to change the number of heating devices HR active during the basic heating load.
  • a ratio of the first time period to the second time period can be determined by the control device 3 or a control computer connected to it and compared with a threshold value. In the event that the calculated value falls below the threshold value, the number of heating devices HR active during the basic heating load can be reduced, in particular by a single heating device HR.
  • the duration ratio can be averaged over a period of several switching cycles and this averaged value can be used to decide the change in the heating devices HR active during the basic heating load.
  • the switching means 4 can also be designed to monitor or monitor the respective heating devices HR connected to them.
  • the switching means 4 can be designed to monitor the electrical load or the electrical power consumption of the heating device HR connected to them. Because of this monitoring or monitoring capability, it can be recognized, for example, when the heating device HR provides no or only a low heating output, which leads to insufficient shrinkage output in the area of the shrink tunnel 6.
  • a monitoring or monitoring output of the switching means 4 can be coupled to the control device 3 and emit an error signal if no or only a low heating output of the heating device HR is detected.
  • the switching means 4 can be designed to permanently disconnect the heating device HR from the power supply system, for example in the event of an electrical short circuit.
  • the switching means 4 can be designed to control the heating device HR in accordance with the vibration packet control. As in Figure 4 shown, in contrast to the phase control, the heating device HR switched only in the zero crossings of the temporal current or voltage profile. In this way, current and voltage transients and thus harmonics can be largely avoided.
  • the switching means 4 can in particular be formed by a semiconductor contactor, for example a 2/3 phase semiconductor contactor (RGC2 / RGC3) from the manufacturer Carlo Gavazzi.
  • the semiconductor contactor has, for example, overvoltage protection, load monitoring means, an alarm output and, if necessary, further auxiliary contacts.
  • Fig. 5 shows the time profile of the electrical power consumption of a device 1 for heating the shrink tunnel 6 by means of the heating devices HR.
  • the jagged curve K1 which fluctuates strongly over time, shows the electrical power consumption of a device according to the prior art described above, in which the basic heating load is selected to be very low and all other heating devices are always switched on and off simultaneously to control the actual temperature.
  • the underlying curve K2 shows a significantly lower frequency of fluctuations over time, with the performance remaining longer at a certain performance level.
  • the amplitude of the change in power is significantly lower.
  • power fluctuations in the electrical power network but also the mechanical load on the heating devices due to frequent switching on and off, can be significantly reduced. It can also be seen that this can reduce the average electrical power consumed by the device 1, so that the energy efficiency of the device 1 is also increased.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Control Of Resistance Heating (AREA)

Description

Die Erfindung bezieht sich auf ein Verfahren und eine Vorrichtung zum Aufschrumpfen eines flächigen Materials auf eine Gruppe von Einzelverpackungen zur Bildung von Gebinden.The invention relates to a method and a device for shrinking a flat material onto a group of individual packagings to form bundles.

In Produktionsanlagen, insbesondere auch in solchen der Getränkeindustrie, ist es bekannt, Einzelverpackungen, beispielsweise Flaschen, Dosen oder dergleichen, die in vorausgehenden Anlagekomponenten oder -maschinen mit einem Produkt gefüllt und verschlossen wurden, einer nachgeordneten Verpackungsmaschine zuzuführen, in der die Einzelverpackungen jeweils zu Packmittelgruppen mit einer vorgegebenen Anzahl von Einzelverpackungen zusammengestellt und die so erzeugten Packmittelgruppen jeweils mit einer Schrumpffolie umhüllt werden. In einer der Verpackungsmaschine nachfolgenden Schrumpfvorrichtung wird aus jeder Packmittelgruppe beim Hindurchfördern derselben durch Aufschrumpfen der Schrumpffolie unter Hitzeeinwirkung jeweils eine feste oder fixierte Verpackungseinheit bzw. ein Gebinde gebildet. Die Wärme innerhalb der Schrumpfvorrichtung kann beispielsweise durch elektrische Heizvorrichtungen erzeugt werden. Die Schrumpfvorrichtung kann beispielsweise mehrere in Transportrichtung der Einzelverpackungen aufeinanderfolgende Heizzonen umfassen.In production plants, especially those in the beverage industry, it is known to feed individual packagings, for example bottles, cans or the like, which have been filled with a product and sealed in preceding plant components or machines, to a downstream packaging machine in which the individual packagings are each grouped into packaging material put together with a predetermined number of individual packagings and the packaging groups produced in this way are each wrapped in a shrink film. In a shrinking device following the packaging machine, a solid or fixed packaging unit or a container is formed from each packaging group as it is conveyed through by shrinking the shrink film under the action of heat. The heat within the shrinking device can be generated, for example, by electrical heating devices. The shrinking device can, for example, comprise a plurality of heating zones following one another in the transport direction of the individual packs.

Insbesondere sind Schrumpfvorrichtungen mit elektrischen Heizvorrichtungen bekannt, die eine relativ niedrige Grundheizlast, beispielsweise eine Grundheizlast von 12 - 15kW pro Heizzone aufweisen. Zur Bereitstellung dieser Grundheizlast ist je Heizzone eine Heizeinrichtung vorgesehen, welche bevorzugt gemeinsam mit dem Hauptschalter des Schrumpftunnels ein- und ausgeschaltet wird. Somit ist diese die Grundheizlast bereitstellende Heizeinrichtung ständig aktiviert.In particular, shrink devices with electrical heating devices are known which have a relatively low basic heating load, for example a basic heating load of 12-15 kW per heating zone. To provide this basic heating load, a heating device is provided for each heating zone, which is preferably switched on and off together with the main switch of the shrink tunnel. This heating device providing the basic heating load is therefore constantly activated.

Die Druckschrift DE 10 2010 020 957 A1 offenbart einen Schrumpftunnel zum Aufbringen von Schrumpffolien auf Packmittel, um dadurch eine Verpackungseinheit bzw. ein Gebinde zu bilden. Entlang einer Transportrichtung sind mehrere Tunnelzonen gebildet, denen jeweils eigene Heizmittel zugeordnet sind. Die Heizmittel können dabei zwischen einer Grundheizlast und einer maximalen Heizleistung gesteuert werden.The pamphlet DE 10 2010 020 957 A1 discloses a shrink tunnel for applying shrink films to packaging material in order to thereby form a packaging unit or a bundle. There are several along one transport direction Tunnel zones formed, each of which is assigned its own heating means. The heating means can be controlled between a basic heating load and a maximum heating output.

Die Druckschrift US 6,394,796 B1 offenbart einen Ofen zum Aushärten von Farben bzw. Beschichtungen. Der Ofen weist einen oder mehrere Temperatursensoren auf, um die Temperatur des zu härtenden Objekts zu messen. US 3678244 A offenbart auch eine Vorrichtung nach Oberbegriff des Anspruchs 15.The pamphlet US 6,394,796 B1 discloses an oven for curing paints or coatings. The oven has one or more temperature sensors to measure the temperature of the object to be hardened. US 3678244 A also discloses an apparatus according to the preamble of claim 15.

Die Temperaturregelung auf die Soll-Temperatur des Schrumpftunnels erfolgt durch die weiteren Heizeinrichtungen der jeweiligen Heizzonen, die beispielsweise eine Leistung von bis zu 60kW pro Heizzone aufweisen. Diese weiteren Heizeinrichtungen können über Schalteinheiten ein- und ausgeschaltet werden. Dabei werden die weiteren Heizeinrichtungen jeweils gemeinsam betrieben, also auch gemeinsam ein- oder ausgeschaltet.The temperature control to the target temperature of the shrink tunnel is carried out by the additional heating devices of the respective heating zones, which for example have an output of up to 60 kW per heating zone. These additional heating devices can be switched on and off via switching units. The further heating devices are each operated jointly, that is to say also switched on or off jointly.

Durch die hohe Heizleistung der weiteren Heizeinrichtungen wird die gewünschte Soll-Temperatur des Schrumpftunnels nach dem Einschalten der Heizeinrichtungen sehr schnell erreicht, was dazu führt, dass die gerade erste eingeschalteten Heizeinrichtungen bereits nach kurzer Zeit wieder ausgeschaltet werden müssen, um die Soll-Temperatur des Schrumpftunnels nicht in unzulässiger Weise zu überschreiten. Im Vergleich zu der niedrigen Leistung der, die Grundheizlast bereitstellenden Heizeinrichtung weisen die weiteren Heizeinrichtungen eine hohe Leistung auf, was dazu führt, dass die weiteren Heizeinrichtungen mit einer hohen Schaltfrequenzen geschaltet werden.Due to the high heating output of the additional heating devices, the desired target temperature of the shrink tunnel is reached very quickly after switching on the heating devices, which means that the heating devices that have just been switched on have to be switched off again after a short time in order to reach the target temperature of the shrink tunnel not to be exceeded in an impermissible manner. In comparison to the low output of the heating device providing the basic heating load, the further heating devices have a high output, which means that the further heating devices are switched with a high switching frequency.

Diese hohe Schaltfrequenz ist von großem Nachteil, insbesondere da dadurch hohe Schaltströme (incl. Stromspitzen durch den Schaltvorgang) von bis zu 100 Ampere pro Zuleitung auftreten können und die Heizeinrichtungen einer hohen mechanischen Belastung durch ständiges Erwärmen und Abkühlen ausgesetzt sind. Weiterhin treten bei der bekannten Schrumpfvorrichtung durch die hohen Schaltströme häufig Netzstörungen, insbesondere Spannungsschwankungen auf, die wiederum so genannte Flickereffekte, also Helligkeitsschwankungen bei Leuchtmitteln hervorrufen.This high switching frequency is a major disadvantage, especially since it can result in high switching currents (including current peaks due to the switching process) of up to 100 amperes per supply line and the heating devices are exposed to high mechanical stress due to constant heating and cooling. Furthermore, due to the high switching currents in the known shrinking device, network disturbances, in particular voltage fluctuations, often occur in turn cause so-called flicker effects, i.e. fluctuations in brightness in light sources.

Ausgehend hiervon ist es Aufgabe der Erfindung, ein Verfahren zum Betreiben einer Schrumpfvorrichtung anzugeben, das zu einer geringeren Schaltfrequenz und dadurch zu geringeren Netzspannungsschwankungen führt.On the basis of this, the object of the invention is to specify a method for operating a shrinking device which leads to a lower switching frequency and thus to lower mains voltage fluctuations.

Die Aufgabe wird durch ein Verfahren gemäß den Merkmalen des unabhängigen Patentanspruchs 1 gelöst. Eine Schrumpfvorrichtung ist Gegenstand des nebengeordneten Patentanspruchs 15.The object is achieved by a method according to the features of independent claim 1. A shrinking device is the subject of the independent claim 15.

Gemäß einem ersten Aspekt bezieht sich die Erfindung auf ein Verfahren zum Betreiben einer Vorrichtung zum Aufschrumpfen eines flächigen Materials auf eine Gruppe von Einzelverpackungen mit zumindest einer Heizzone mit mehreren elektrischen Heizeinrichtungen, wobei das Verfahren die folgenden Verfahrensschritte umfasst:

  • Erfassen der Ist-Temperatur im Bereich der Heizzone und Vergleichen der Ist-Temperatur im Bereich der Heizzone mit einer Solltemperatur;
  • Wechseln in einen ersten Betriebsmodus durch Reduzieren der Anzahl der aktiven Heizeinrichtungen in der Heizzone auf eine vordefinierte Anzahl von Heizeinrichtungen, wenn die Ist-Temperatur im Bereich der Heizzone die Solltemperatur überschritten hat, wobei die vordefinierte Anzahl von Heizeinrichtungen unter Berücksichtigung zumindest eines Betriebsparameters bestimmt wurde; und
  • Wechseln von dem ersten Betriebsmodus in einen zweiten Betriebsmodus durch Erhöhen der Anzahl der aktiven Heizeinrichtungen in der Heizzone zur Erhöhung der Ist-Temperatur im Bereich der Heizzone auf die Solltemperatur.
According to a first aspect, the invention relates to a method for operating a device for shrinking a flat material onto a group of individual packages with at least one heating zone with several electrical heating devices, the method comprising the following method steps:
  • Detecting the actual temperature in the area of the heating zone and comparing the actual temperature in the area of the heating zone with a target temperature;
  • Switching to a first operating mode by reducing the number of active heating devices in the heating zone to a predefined number of heating devices when the actual temperature in the area of the heating zone has exceeded the setpoint temperature, the predefined number of heating devices having been determined taking into account at least one operating parameter; and
  • Change from the first operating mode to a second operating mode by increasing the number of active heating devices in the heating zone to increase the actual temperature in the area of the heating zone to the target temperature.

Der wesentliche Vorteil des erfindungsgemäßen Verfahrens besteht darin, dass in dem ersten Betriebsmodus, in dem die Anlage mit der Grundheizlast betrieben wird, die Heizleistung (Grundheizleistung) nicht starr vorgegeben ist, sondern die im ersten Betriebsmodus aktive Anzahl von Heizeinrichtungen und damit die Höhe der Grundheizleistung basierend auf Betriebsparameter bestimmt wird, so dass durch eine geeignete Wahl der Grundheizleistung eine reduzierte Häufigkeit des An- bzw. Abschaltens der Heizeinrichtungen und damit reduzierte Netzspannungsschwankungen und reduzierte thermische Belastungen an den Heizeinrichtungen entstehen.The main advantage of the method according to the invention is that in the first operating mode, in which the system is operated with the basic heating load, the heating output (basic heating output) is not rigidly specified, but rather the number of heating devices active in the first operating mode and thus the amount of heating Basic heating power is determined based on operating parameters, so that a suitable choice of the basic heating power results in a reduced frequency of switching on and off the heating devices and thus reduced mains voltage fluctuations and reduced thermal loads on the heating devices.

Gemäß einem Ausführungsbeispiel ist die Anzahl der aktiven Heizeinrichtungen im ersten Betriebsmodus von der Solltemperatur in der Heizzone abhängig. Die Solltemperatur innerhalb der jeweiligen Heizzone bestimmt maßgeblich den Wärmebedarf und damit die bereitzustellende Heizleistung. Weitere Betriebsparameter, die Einfluss auf die Anzahl der aktiven Heizeinrichtungen im ersten Betriebsmodus nehmen können, sind beispielsweise die Umgebungstemperatur, der durchschnittliche Leistungsbedarf der Heizzone bzw. der gesamten Heizeinrichtungen in einem zurückliegenden Zeitraum, beispielsweise den vergangenen n Minuten, wobei n eine rationale Zahl sein kann, etc. Dadurch kann die Grundheizleistung an die aktuell vorherrschende Betriebssituation angepasst werden.According to one exemplary embodiment, the number of active heating devices in the first operating mode is dependent on the setpoint temperature in the heating zone. The target temperature within the respective heating zone largely determines the heat requirement and thus the heating output to be provided. Further operating parameters that can influence the number of active heating devices in the first operating mode are, for example, the ambient temperature, the average power requirement of the heating zone or the entire heating devices in a previous period, for example the past n minutes, where n can be a rational number , etc. This means that the basic heating output can be adapted to the current operating situation.

Gemäß einem Ausführungsbeispiel ist die Anzahl der aktiven Heizeinrichtungen im ersten Betriebsmodus gleich oder größer als zwei. In anderen Worten wird zur Erzeugung der Grundheizleistung nicht nur lediglich eine einzige Heizeinrichtung verwendet sondern mindestens zwei. Vorzugsweise wird durch die zumindest zwei aktiven Heizeinrichtungen eine Grundheizlast von mehr als 15KW bereitgestellt. Dadurch wird der dauerhaft betriebene Anteil der Heizeinrichtungen erhöht und der intermittierend zugeschaltete Anteil der Heizeinrichtungen verringert.According to one embodiment, the number of active heating devices in the first operating mode is equal to or greater than two. In other words, not just a single heating device is used to generate the basic heating output, but at least two. A basic heating load of more than 15KW is preferably provided by the at least two active heating devices. As a result, the permanently operated portion of the heating devices is increased and the intermittently connected portion of the heating devices is reduced.

Gemäß einem Ausführungsbeispiel ist die Anzahl der aktiven Heizeinrichtungen im zweiten Betriebsmodus um eins größer als die Anzahl der aktiven Heizeinrichtungen im ersten Betriebsmodus. In anderen Worten wird zusätzlich zu den die Grundheizleistung bereitstellenden Heizeinrichtungen intermittierend lediglich eine weitere Heizeinrichtung zugeschaltet, um die Temperatur in der Heizzone auf die Solltemperatur zu erhöhen. Dadurch können die durch die Schaltvorgänge hervorgerufenen Leistungsveränderungen und damit die Spannungsschwankungen im elektrischen Netz wesentlich reduziert werden.According to one embodiment, the number of active heating devices in the second operating mode is one greater than the number of active heating devices in the first operating mode. In other words, in addition to the heating devices providing the basic heating power, only one additional heating device is intermittently switched on in order to increase the temperature in the heating zone to the setpoint temperature. This allows the through the switching operations caused changes in performance and thus the voltage fluctuations in the electrical network are significantly reduced.

Gemäß einem Ausführungsbeispiel wird die Anzahl der aktiven Heizeinrichtungen im ersten Betriebsmodus durch eine Steuereinrichtung unter Berücksichtigung zumindest eines Betriebsparameters berechnet. Damit kann die Grundheizleistung automatisch angepasst werden. Alternativ ist es möglich, dass die Grundheizleistung durch das Bedienpersonal abhängig von Betriebsparametern manuell eingestellt wird.According to one embodiment, the number of active heating devices in the first operating mode is calculated by a control device, taking into account at least one operating parameter. This means that the basic heating output can be adjusted automatically. Alternatively, it is possible that the basic heating output is set manually by the operating personnel depending on the operating parameters.

Gemäß einem Ausführungsbeispiel wird die Anzahl der im ersten Betriebsmodus aktiven Heizeinrichtungen während des Betriebs der Vorrichtung fußend auf Betriebsparameter kontinuierlich oder intermittierend berechnet. Dadurch kann die Grundheizleistung fortlaufend an Veränderungen der Betriebssituation angepasst werden.According to one embodiment, the number of heating devices active in the first operating mode is calculated continuously or intermittently during operation of the device based on operating parameters. This means that the basic heating output can be continuously adapted to changes in the operating situation.

Gemäß einem Ausführungsbeispiel wird die Anzahl der im ersten Betriebsmodus aktiven Heizeinrichtungen unter Berücksichtigung der durch das Aktivieren und/oder Deaktivieren der jeweiligen Heizeinrichtungen hervorgerufenen Temperaturveränderungen in der jeweiligen Heizzone ermittelt. Beispielsweise kann der zeitliche Verlauf der Temperaturveränderung nach dem Aktivieren bzw. Deaktivieren einer gewissen Heizeinrichtung ermittelt und daraus abgeleitet werden, ob diese Heizeinrichtung zur Bereitstellung der Grundheizleistung aktiviert werden soll oder nicht.According to one embodiment, the number of heating devices active in the first operating mode is determined taking into account the temperature changes in the respective heating zone caused by the activation and / or deactivation of the respective heating devices. For example, the time profile of the temperature change after activating or deactivating a certain heating device can be determined and derived therefrom whether or not this heating device should be activated to provide the basic heating output.

Die der jeweiligen Heizzone zugeordneten Heizeinrichtungen können dabei jeweils die gleiche Heizleistung oder unterschiedliche Heizleistung aufweisen. Vorzugsweise kann bei Heizeinrichtungen mit unterschiedlicher Heizleistung diejenige Heizeinrichtung zur Bereitstellung der Grundheizleistung aktiviert werden, die möglichst genau den Leistungsbedarf abdeckt, der bei einer gewissen Betriebssituation (z.B. Solltemperatur, Umgebungstemperatur etc.) reduzierte Schaltaktivitäten hervorruft.The heating devices assigned to the respective heating zone can each have the same heating output or different heating output. Preferably, in heating devices with different heating power, that heating device can be activated to provide the basic heating power, which as precisely as possible covers the power requirement that causes reduced switching activities in a certain operating situation (e.g. target temperature, ambient temperature, etc.).

Gemäß einem Ausführungsbeispiel wird die Anzahl der im ersten Betriebsmodus aktiven Heizeinrichtungen um eins reduziert, wenn im zweiten Betriebsmodus die gemessene Ist-Temperatur im Bereich der Heizzone die Solltemperatur um einen vorgegebenen Temperaturdifferenzwert für eine vorgegebene Zeitdauer überschreitet. Dies ist ein Hinweis darauf, dass die Grundheizleistung zu hoch gewählt ist und dadurch eine hohe Schaltaktivität bei den intermittierend zugeschalteten Heizeinrichtungen hervorgerufen wird.According to one embodiment, the number of heating devices active in the first operating mode is reduced by one if, in the second operating mode, the measured actual temperature in the area of the heating zone exceeds the setpoint temperature by a predetermined temperature difference value for a predetermined period of time. This is an indication that the basic heating output has been selected too high and that this causes a high level of switching activity in the heating devices that are switched on intermittently.

Gemäß einem Ausführungsbeispiel liegt der Temperaturdifferenzwert im Bereich zwischen 1°C und 5°C, insbesondere bei 2°C, 3°C oder4°C.According to one embodiment, the temperature difference value is in the range between 1 ° C and 5 ° C, in particular at 2 ° C, 3 ° C or 4 ° C.

Gemäß einem Ausführungsbeispiel liegt die vorgegebene Zeitdauer im Bereich zwischen 30sec und 3min und insbesondere 1min, 1,5min oder 2min oder mehr beträgt.According to one exemplary embodiment, the predefined period of time is in the range between 30 seconds and 3 minutes and in particular is 1 minute, 1.5 minutes or 2 minutes or more.

Gemäß einem Ausführungsbeispiel wird die Anzahl der im ersten Betriebsmodus aktiven Heizeinrichtungen um eins reduziert, wenn das Verhältnis der Zeitdauer, in der sich die Vorrichtung im zweiten Betriebsmodus befindet, zu der Zeitdauer, in der sich die Vorrichtung im ersten Betriebsmodus befindet, einen Schwellwert unterschreitet. In anderen Worten wird das Zeitdauerverhältnis bestimmt, das angibt wie lange die Heizzone mit Grundheizleistung betrieben wird. Abhängig von diesem Wert wird die Grundheizleistung verringert, wenn das Zeitdauerverhältnis angibt, dass die Heizzone nur immer sehr kurz mit einer Heizleistung über der Grundheizleistung betrieben wird.According to one embodiment, the number of heating devices active in the first operating mode is reduced by one if the ratio of the time period in which the device is in the second operating mode to the time period in which the device is in the first operating mode falls below a threshold value. In other words, the duration ratio is determined, which indicates how long the heating zone is operated with basic heating power. Depending on this value, the basic heating output is reduced if the duration ratio indicates that the heating zone is only operated very briefly with a heating output above the basic heating output.

Gemäß einem Ausführungsbeispiel wird das Verhältnis der Zeitdauern über mehrere Schaltzyklen hinweg ermittelt. Dadurch kann ein Mittelwert des Zeitdauerverhältnisses errechnet werden. Basierend auf dem Zeitdauerverhältnis kann dann eine Entscheidung über die Reduzierung der Grundheizleistung getroffen werden.According to one embodiment, the ratio of the periods of time is determined over a number of switching cycles. In this way, an average value of the time duration ratio can be calculated. A decision on reducing the basic heating output can then be made based on the duration ratio.

Gemäß einem Ausführungsbeispiel erfolgt das Aktivieren und Deaktivieren der Heizeinrichtungen durch Schaltmittel, wobei die Schaltmittel vorzugsweise auch die, durch sie geschaltete elektrische Last überwachen. Dadurch ist es möglich, basierend auf den Schaltmitteln den Zustand der Heizeinrichtungen zu kontrollieren, beispielsweise einen Ausfall durch Unterbrechen eines Heizleiters oder einen Kurzschluss zu erkennen.According to an exemplary embodiment, the heating devices are activated and deactivated by switching means, the switching means preferably also including the monitor electrical load switched by them. This makes it possible, based on the switching means, to control the state of the heating devices, for example to recognize a failure due to the interruption of a heating conductor or a short circuit.

Gemäß einem Ausführungsbeispiel erfolgt das Aktivieren und Deaktivieren der Heizeinrichtungen durch zumindest eine Schalteinrichtung, die zum Schalten der Heizeinrichtungen nach dem Prinzip der Schwingungspaketsteuerung ausgebildet ist. Insbesondere ist die Schalteinrichtung dazu ausgebildet, die Heizeinrichtungen in Nulldurchgängen des Strom- bzw. Spannungsverlaufs zu aktivieren bzw. zu deaktivieren. Dadurch werden Strom- und Spannungs-Transienten und damit Oberschwingungen weitgehend vermieden.According to one exemplary embodiment, the heating devices are activated and deactivated by at least one switching device which is designed to switch the heating devices according to the principle of vibration packet control. In particular, the switching device is designed to activate or deactivate the heating devices in zero crossings of the current or voltage profile. This largely avoids current and voltage transients and thus harmonics.

Gemäß einem Ausführungsbeispiel erfolgt das Aufheizen der Heizzone durch Aktivieren, insbesondere zeitversetztes Aktivieren sämtlicher Heizeinrichtungen. Dadurch können die Lastveränderung zeitlich verteilt und damit die Auswirkungen auf das elektrische Netz reduziert werden.According to one exemplary embodiment, the heating zone is heated by activating, in particular by activating all heating devices with a delay. As a result, the change in load can be distributed over time and thus the effects on the electrical network can be reduced.

Des Weiteren bezieht sich die Erfindung auf eine Vorrichtung zum Aufschrumpfen eines flächigen Materials auf eine Gruppe von Einzelverpackungen. Die Vorrichtung umfasst zumindest eine mehrere elektrische Heizeinrichtungen aufweisende Heizzone und einen Temperatursensor zur Ermittlung der Ist-Temperatur im Bereich der Heizzone, wobei eine Steuereinrichtung vorgesehen ist, die zum Empfang von Informationen bezüglich der Ist-Temperatur im Bereich der Heizzone und zum Veranlassen eines Umschaltens der Vorrichtung von einem ersten Betriebsmodus in einen zweiten Betriebsmodus ausgebildet ist. Zudem sind Schaltmittel vorgesehen, die mit der Steuereinrichtung derart zusammenwirken, dass in einen ersten Betriebsmodus gewechselt wird, indem die Anzahl der aktiven Heizeinrichtungen auf eine vordefinierte Anzahl von Heizeinrichtungen reduziert wird, wenn die Ist-Temperatur im Bereich der Heizzone eine Solltemperatur überschritten hat, wobei die vordefinierte Anzahl von Heizeinrichtungen unter Berücksichtigung zumindest eines Betriebsparameters bestimmt wurde. Weiterhin wirken die Schaltmittel mit der Steuereinrichtung derart zusammen, dass von dem ersten Betriebsmodus in einen zweiten Betriebsmodus umgeschaltet wird, indem die Anzahl der aktiven Heizeinrichtungen zur Regelung der Ist-Temperatur im Bereich der Heizzone auf die Solltemperatur erhöht wird.The invention also relates to a device for shrinking a flat material onto a group of individual packagings. The device comprises at least one heating zone having a plurality of electrical heating devices and a temperature sensor for determining the actual temperature in the area of the heating zone, a control device being provided which is used to receive information relating to the actual temperature in the area of the heating zone and to initiate a switchover of the Device is designed from a first operating mode to a second operating mode. In addition, switching means are provided which interact with the control device in such a way that a change is made to a first operating mode by reducing the number of active heating devices to a predefined number of heating devices when the actual temperature in the area of the heating zone has exceeded a setpoint temperature, with the predefined number of heating devices was determined taking into account at least one operating parameter. Furthermore, the switching means interact with the control device in such a way that from the first operating mode into one The second operating mode is switched over by increasing the number of active heating devices for regulating the actual temperature in the area of the heating zone to the setpoint temperature.

Der Ausdruck "im Wesentlichen" bzw. "etwa" bedeutet im Sinne der Erfindung Abweichungen vom jeweils exakten Wert um +/- 10%, bevorzugt um +/- 5% und/oder Abweichungen in Form von für die Funktion unbedeutenden Änderungen.The expression “essentially” or “approximately” means deviations from the exact value in each case by +/- 10%, preferably by +/- 5% and / or deviations in the form of changes that are insignificant for the function.

Weiterbildungen, Vorteile und Anwendungsmöglichkeiten der Erfindung ergeben sich auch aus der nachfolgenden Beschreibung von Ausführungsbeispielen und aus den Figuren. Dabei sind alle beschriebenen und/oder bildlich dargestellten Merkmale für sich oder in beliebiger Kombination grundsätzlich Gegenstand der Erfindung, unabhängig von ihrer Zusammenfassung in den Ansprüchen oder deren Rückbeziehung. Auch wird der Inhalt der Ansprüche zu einem Bestandteil der Beschreibung gemacht.Developments, advantages and possible applications of the invention also emerge from the following description of exemplary embodiments and from the figures. In this case, all of the features described and / or shown in the figures, individually or in any combination, are fundamentally the subject matter of the invention, regardless of how they are summarized in the claims or their reference. The content of the claims is also made part of the description.

Die Erfindung wird im Folgenden anhand der Figuren an Ausführungsbeispielen näher erläutert. Es zeigen:

Fig. 1
beispielhaft und grob schematisch ein Ausführungsbeispiel einer Schrumpfvorrichtung mit mehreren Heizzonen in einer oberseitigen Ansicht;
Fig. 2
beispielhaft und grob schematisch eine Darstellung zweier Heizzonen mit Heizeinrichtungen und diesen zugeordneten Schaltmitteln;
Fig. 3
beispielhaft und grob schematisch ein Temperaturdiagramm, das das Zusammenwirken der Heizeinrichtungen zur Erzielung einer gewissen Temperatur in der Heizzone veranschaulicht;
Fig.4
beispielhaft und schematisch der zeitliche Strom- bzw. Spannungsverlauf in einem Wechselstromnetz, basierend auf dem ein Schalten der Heizeinrichtungen gemäß der Schwingungspaketsteuerung erfolgen kann; und
Fig. 5
beispielhaft und schematisch zwei zeitliche Verläufe der Leistungsaufnahme der Heizeinrichtungen einer oder mehrerer Heizzonen.
The invention is explained in more detail below with reference to the figures using exemplary embodiments. Show it:
Fig. 1
by way of example and roughly schematically an embodiment of a shrinking device with several heating zones in a top view;
Fig. 2
an example and roughly schematic representation of two heating zones with heating devices and switching means assigned to them;
Fig. 3
by way of example and roughly schematically a temperature diagram which illustrates the interaction of the heating devices to achieve a certain temperature in the heating zone;
Fig. 4
by way of example and schematically the temporal current or voltage profile in an alternating current network, based on which the heating devices can be switched according to the vibration packet control; and
Fig. 5
by way of example and schematically two time curves of the power consumption of the heating devices of one or more heating zones.

In Figur 1 ist mit dem Bezugszeichen 1 eine Vorrichtung zum Aufschrumpfen eines flächigen Materials auf eine Gruppe von Einzelverpackungen gezeigt. Derartige Vorrichtungen 1 werden auch als Schrumpfvorrichtung bezeichnet. Die Vorrichtung 1 umfasst einen Transporteur 5, auf dem gruppierte Einzelverpackungen, beispielsweise Flaschen, Dosen oder andere Packmittel, als Packmittelgruppen mit einem flächigen Material umhüllt einem Schrumpftunnel 6 zugeführt werden. Das flächige Material kann insbesondere eine aus einem Kunststoffmaterial bestehende Folie sein, die sich unter Hitzeeinwirkung zusammenzieht und damit die Einzelverpackungen zu einem Gebinde zusammenfasst.In Figure 1 the reference numeral 1 shows a device for shrinking a flat material onto a group of individual packages. Such devices 1 are also referred to as shrinking devices. The device 1 comprises a conveyor 5, on which grouped individual packagings, for example bottles, cans or other packaging materials, are fed as packaging material groups wrapped in a flat material to a shrink tunnel 6. The flat material can in particular be a film made of a plastic material, which contracts under the action of heat and thus combines the individual packagings to form a container.

Der Schrumpftunnel 6 weist im gezeigten Ausführungsbeispiel mehrere Heizzonen I, II auf, in denen jeweils mehrere elektrische Heizeinrichtungen HR zur Erzeugung der, für das Aufschrumpfen des flächigen Materials nötigen Wärme vorgesehen sind. Die elektrischen Heizeinrichtungen HR können jegliche durch elektrischen Strom betriebene Heizeinrichtungen sein, insbesondere Widerstandsheizungen mit zumindest einer Heizwendel.In the exemplary embodiment shown, the shrink tunnel 6 has a plurality of heating zones I, II, in each of which a plurality of electrical heating devices HR are provided for generating the heat required for shrinking the flat material. The electrical heating devices HR can be any heating devices operated by electrical current, in particular resistance heaters with at least one heating coil.

Zur Steuerung der Temperatur innerhalb der jeweiligen Heizzone I, II ist ein Temperatursensor vorgesehen. Insbesondere weist jede Heizzone I, II zumindest einen Temperatursensor auf, mittels dem die Ist-Temperatur im Bereich dieser Heizzone I, II erfasst wird. Basierend auf der, durch diesen Temperatursensor gewonnenen Informationen ist es möglich, die Ist-Temperatur innerhalb der Heizzone I, II derart zu steuern und/oder zu regeln, dass diese im Bereich einer Soll-Temperatur ST eingeregelt wird. Diese Soll-Temperatur ST hängt insbesondere von dem die Packmittelgruppe umhüllenden Material, der Fördergeschwindigkeit des Transporteurs 5 bzw. der Verweildauer einer Packmittelgruppe in der jeweiligen Heizzone I, II etc. ab. Diese kann beispielsweise im Bereich zwischen 150 °C und 250 °C, insbesondere zwischen 170 °C und 200 °C liegen. Die Soll-Temperatur ST kann für die unterschiedlichen Heizzonen I, II unterschiedlich hoch gewählt sein.A temperature sensor is provided to control the temperature within the respective heating zone I, II. In particular, each heating zone I, II has at least one temperature sensor, by means of which the actual temperature in the area of this heating zone I, II is recorded. Based on the information obtained by this temperature sensor, it is possible to control and / or regulate the actual temperature within the heating zone I, II in such a way that it is regulated in the range of a target temperature ST. This target temperature ST depends in particular on the material enveloping the packaging group, the conveying speed of the conveyor 5 or the dwell time of a packaging group in the respective heating zone I, II, etc.. This can for example be in the range between 150 ° C and 250 ° C, in particular between 170 ° C and 200 ° C. The target temperature ST can be selected to be different for the different heating zones I, II.

Die Vorrichtung 1 weist des Weiteren eine Steuereinrichtung 3 auf. Die Steuereinrichtung 3 ist insbesondere zur Steuerung der Temperatur innerhalb der jeweiligen Heizzone I, II ausgebildet. Diese Steuerung kann insbesondere durch Einschalten bzw. Ausschalten der Heizeinrichtungen HR der jeweiligen Heizzone I, II erfolgen. Die Steuereinrichtung 3 ist dabei vorzugsweise mit dem in der Heizzone I, II vorgesehenen Temperatursensor verbunden und erhält von diesem Informationen hinsichtlich der Ist-Temperatur innerhalb der Heizzone I, II. Die Steuereinrichtung 3 ist dazu ausgebildet, die Ist-Temperatur innerhalb der Heizzone I, II mit einer Solltemperatur ST zu vergleichen und basierend auf diesem Vergleichsergebnis die Ansteuerung der Heizeinrichtungen HR d.h. das intermittierende Aktivieren und Deaktivieren der Heizeinrichtungen HR in der jeweiligen Heizzone I, II vorzunehmen. Letztlich weist die beschriebene Steuereinrichtung 3 die Funktion einer Regeleinrichtung auf, so dass die Begriffe Steuerung und Regelung im Rahmen der vorliegenden Anmeldung stets unter Beachtung der jeweils zugehörigen Stellen der Beschreibung zu interpretieren sind.The device 1 also has a control device 3. The control device 3 is designed in particular to control the temperature within the respective heating zone I, II. This control can take place in particular by switching on or off the heating devices HR of the respective heating zone I, II. The control device 3 is preferably connected to the temperature sensor provided in the heating zone I, II and receives information therefrom regarding the actual temperature within the heating zone I, II. The control device 3 is designed to measure the actual temperature within the heating zone I, II to compare with a setpoint temperature ST and, based on this comparison result, the control of the heating devices HR, ie the intermittent activation and deactivation of the heating devices HR in the respective heating zone I, II to be carried out. Ultimately, the control device 3 described has the function of a regulating device, so that the terms control and regulation in the context of the present application are always to be interpreted taking into account the respective passages of the description.

Das Aktivieren bzw. Deaktivieren (Anschalten bzw. Abschalten) der Heizeinrichtungen HR erfolgt durch Schaltmittel 4. Insbesondere ist, wie in Figur 2 gezeigt, jeder Heizeinrichtung HR ein eigenständiges Schaltmittel 4 zugeordnet, so dass jede Heizeinrichtung HR unabhängig von den anderen Heizeinrichtungen aktiviert bzw. deaktiviert werden kann. Das Schaltmittel 4 kann insbesondere durch einen Halbleiterschütz gebildet werden.The heating devices HR are activated or deactivated (switched on or switched off) by switching means 4. In particular, as in FIG Figure 2 As shown, each heating device HR is assigned an independent switching means 4, so that each heating device HR can be activated or deactivated independently of the other heating devices. The switching means 4 can in particular be formed by a semiconductor contactor.

Nachfolgend wird die Steuerung der Vorrichtung 1 basierend auf der Darstellung in Figur 3 näher erläutert. Bei der Inbetriebnahme der Vorrichtung 1 wird zunächst der Innenraum des Schrumpftunnels 6 durch die Heizeinrichtungen HR aufgeheizt. Dabei werden zunächst sämtliche Heizeinrichtungen HR aktiviert, so dass die Heizzone I, II mit maximaler Heizleistung aufgeheizt wird. Die Ist-Temperatur innerhalb der jeweiligen Heizzone I, II wird dabei durch den Temperatursensor erfasst und die Heizzonen I, II werden so lange mit maximaler Heizleistung betrieben, bis die Ist-Temperatur die Solltemperatur ST erreicht bzw. überschritten hat. Anschließend wird die Anzahl der aktiven, d.h. der eingeschalteten Heizeinrichtungen HR reduziert, so dass die jeweilige Heizzone I, II mit einer Grundheizlast beheizt wird, die durch eine Anzahl von aktiven Heizeinrichtungen HR in der jeweiligen Heizzone I, II definiert wird. Die Anzahl der aktiven Heizeinrichtungen HR pro Heizzone I, II bei der Grundheizlast beträgt vorzugsweise mindestens zwei Heizeinrichtungen HR pro Heizzone I, II.The control of the device 1 is subsequently carried out based on the illustration in FIG Figure 3 explained in more detail. When the device 1 is put into operation, the interior of the shrink tunnel 6 is first heated by the heating devices HR. First of all, all heating devices HR are activated, so that heating zones I, II are heated up with maximum heating power. The actual temperature within the respective heating zone I, II is detected by the temperature sensor and the heating zones I, II are operated with maximum heating power until the actual temperature has reached or exceeded the target temperature ST. The number of active, ie switched on, heating devices HR is then reduced so that the respective heating zone I, II is heated with a basic heating load that is generated by a Number of active heating devices HR in the respective heating zone I, II is defined. The number of active heating devices HR per heating zone I, II with the basic heating load is preferably at least two heating devices HR per heating zone I, II.

Die Regelung der Heizleistung pro Heizzone I, II und damit auch die Regelung der Ist-Temperatur innerhalb der jeweiligen Heizzone I, II auf die gewünschte Solltemperatur ST erfolgt durch die Steuereinrichtung 3, die Steuersignale an die Schaltmittel 4 abgibt, um dadurch ein Aktivieren bzw. Deaktivieren der Heizeinrichtungen HR zu erreichen. Die Heizeinrichtungen HR werden dabei vorzugsweise stets mit einer festen elektrischen Leistung betrieben, deren Betrag nicht veränderbar ist. Die Heizeinrichtungen HR werden also lediglich digital geschaltet (an/aus).The regulation of the heating power per heating zone I, II and thus also the regulation of the actual temperature within the respective heating zone I, II to the desired target temperature ST is carried out by the control device 3, which sends control signals to the switching means 4 in order to activate or Deactivating the heating devices to achieve HR. The heating devices HR are preferably always operated with a fixed electrical power, the amount of which cannot be changed. The heating devices HR are therefore only switched digitally (on / off).

Um die Häufigkeit der Schaltvorgänge zu reduzieren und damit die Lastschwankungen im Stromnetz zu verringern, wird die für die Grundheizlast nötige Anzahl von aktiven Heizeinrichtungen HR in Abhängigkeit von Betriebsparametern der Vorrichtung 1 vorab bestimmt. Die Bestimmung der Anzahl von aktiven Heizeinrichtungen HR zur Erreichung der Grundheizlast kann beispielsweise basierend auf Erfahrungswerten des Bedienpersonals erfolgen und manuell bzw. durch entsprechende Eingaben an der Maschinensteuerung eingestellt werden. Alternativ ist es möglich, dass die Steuereinrichtung 3 oder ein damit verbundener Steuerrechner die für die Erreichung der Grundheizlast nötigen aktiven Heizeinrichtungen HR berechnet und dieser berechnete Wert zum Betrieb der Vorrichtung 1 bei Grundheizlast herangezogen wird. Zu dieser Berechnung können insbesondere Betriebsparameter wie z.B. die Solltemperatur ST, die Umgebungstemperatur, Informationen hinsichtlich in der Vergangenheit erfolgter Schaltvorgänge etc. herangezogen werden.In order to reduce the frequency of the switching operations and thus the load fluctuations in the power grid, the number of active heating devices HR required for the basic heating load is determined in advance as a function of operating parameters of the device 1. The number of active heating devices HR to achieve the basic heating load can be determined, for example, based on empirical values of the operating personnel and set manually or by means of appropriate inputs on the machine control. Alternatively, it is possible for the control device 3 or a control computer connected to it to calculate the active heating devices HR required to achieve the basic heating load and for this calculated value to be used to operate the device 1 during the basic heating load. In particular, operating parameters such as the target temperature ST, the ambient temperature, information regarding switching operations carried out in the past, etc. can be used for this calculation.

Die Anzahl von aktiven Heizeinrichtungen HR zur Erreichung bzw. kontinuierliche Bereitstellung der Grundheizlast ist dabei vorzugsweise derart gewählt, dass die durch diese Heizeinrichtungen HR erreichte Heizleistung kleiner ist als die für die Erreichung der Solltemperatur ST notwendige Heizleistung. Dadurch wird erreicht, dass nach dem vorher beschriebenen Aufheizvorgang, nach dem Erreichen oder Überschreiten der Solltemperatur ST durch Betreiben der Vorrichtung 1 bei der Grundheizlast durch Deaktivieren zumindest einer Heizeinrichtung HR gegenüber dem Aufheizvorgang ein Absinken der Ist-Temperatur in der Heizzone I, II erfolgt. In anderen Worten wird nach dem Aufheizvorgang der jeweiligen Heizzone I, II diese Heizzone I, II zunächst mit der Grundheizlast betrieben.The number of active heating devices HR for achieving or continuously providing the basic heating load is preferably selected in such a way that the heating output achieved by these heating devices HR is less than the heating output required to achieve the setpoint temperature ST. This achieves that after the previously described heating process, after reaching or exceeding the target temperature ST by operating the device 1 at the basic heating load by deactivating at least one heating device HR compared to the heating process, the actual temperature in the heating zone I, II drops. In other words, after the heating process of the respective heating zone I, II, this heating zone I, II is initially operated with the basic heating load.

Alternativ erfolgt die beschriebene Umschaltung bereits kurz bevor die Ist-Temperatur die Solltemperatur ST erreicht, was zur Folge hat, dass ein Überschwingen der Ist-Temperatur über die Solltemperatur ST sicher vermieden wird.Alternatively, the described switchover takes place shortly before the actual temperature reaches the setpoint temperature ST, with the result that the actual temperature is reliably prevented from overshooting the setpoint temperature ST.

Nachdem beim Betrieb bei Grundheizlast die Ist-Temperatur in der Heizzone I, II unter einen Schwellwert gefallen ist, wird die Anzahl der aktiven Heizeinrichtungen erhöht, und zwar vorzugsweise um eine einzige Heizeinrichtung HR (für die jeweilige Heizzone I, II), so dass die nunmehr bereitgestellte Heizleistung in der Heizzone I, II größer ist als der Wärmeverlust, so dass die Ist-Temperatur in der Heizzone I, II erneut ansteigt. Somit wird zur Regelung der Ist-Temperatur in der Heizzone I, II auf Solltemperatur ST vorzugsweise lediglich eine Heizeinrichtung HR intermittierend an- und abgeschaltet, so dass die Variation der für die Beheizung benötigten elektrischen Leistung im Vergleich zum Stand der Technik minimiert wird.After the actual temperature in heating zone I, II has fallen below a threshold value during operation with the basic heating load, the number of active heating devices is increased, preferably by a single heating device HR (for the respective heating zone I, II) so that the The heating output now provided in the heating zone I, II is greater than the heat loss, so that the actual temperature in the heating zone I, II rises again. Thus, to regulate the actual temperature in the heating zone I, II to the target temperature ST, only one heating device HR is switched on and off intermittently so that the variation in the electrical power required for heating is minimized compared to the prior art.

Gemäß dem in Figur 3 gezeigten Ausführungsbeispiel weist eine Heizzone I, II vier Heizeinrichtungen HR1, HR2, HR3, HR4 auf, die unabhängig voneinander aktivierbar sind. Die Heizeinrichtungen HR1, HR2, HR3, HR4 bewirken durch ihre gemeinsame Aktivierung eine Temperatur in der Heizzone I, II gemäß dem Temperaturdiagramm in Fig. 3.According to the in Figure 3 The embodiment shown has a heating zone I, II four heating devices HR1, HR2, HR3, HR4, which can be activated independently of one another. The heating devices HR1, HR2, HR3, HR4 bring about a temperature in the heating zone I, II according to the temperature diagram in FIG Fig. 3 .

Um beispielsweise eine Soll-Temperatur von 180°C in der Heizzone I, II zu erhalten, würde die Aufheizung der Heizzone zunächst mittels Aktivierung aller vier Heizeinrichtungen HR1, HR2, HR3, HR4 erfolgen. Nachdem die Aufheizung der Heizzone vollzogen ist, würde die Heizeinrichtung HR4 deaktiviert werden und die Heizeinrichtungen HR1, HR2, HR3 würden aktiviert bleiben. Da die Heizleistung der verbleibenden drei Heizeinrichtungen HR1, HR2, HR3 geringer ist als der bei der gewünschten Soll-Temperatur vorhandene Wärmeverlust würde die Ist-Temperatur (nach ggf. vorhandenen Nachheizeffekten) zunächst absinken. Wenn die Ist-Temperatur unter einen gewissen unteren Schwellwert gesunken ist, würde die Heizeinrichtung HR4 erneut aktiviert, was zu einem erneuten Ansteigen der Ist-Temperatur führt. Die Temperaturregelung würde dann durch intermittierendes Aktivieren/Deaktivieren der Heizeinrichtung HR4 bei konstantem Betrieb der Heizeinrichtungen HR1, HR2, HR3 erfolgen. Dadurch können die Lastschwankungen im elektrischen Stromnetz und die Schaltfrequenz erheblich reduziert werden.For example, in order to obtain a target temperature of 180 ° C. in heating zone I, II, the heating zone would first be heated by activating all four heating devices HR1, HR2, HR3, HR4. After the heating zone has been heated up, the heating device HR4 would be deactivated and the heating devices HR1, HR2, HR3 would remain activated. Since the heating power of the remaining three heating devices HR1, HR2, HR3 is less than that of the If there is any heat loss at the desired setpoint temperature, the actual temperature (after possibly existing reheating effects) would initially drop. If the actual temperature has fallen below a certain lower threshold value, the heating device HR4 would be activated again, which leads to a renewed increase in the actual temperature. The temperature control would then take place by intermittent activation / deactivation of the heating device HR4 with constant operation of the heating devices HR1, HR2, HR3. As a result, the load fluctuations in the electrical power grid and the switching frequency can be reduced considerably.

Bevorzugt ist die Vorrichtung 1, vorzugsweise die Steuereinrichtung 3 der Vorrichtung 1 dazu ausgebildet, die durch Aktivieren/Deaktivieren der Heizeinrichtungen HR hervorgerufenen zeitlichen Temperaturveränderungen zu erfassen und basierend darauf die Anzahl der zum Betreiben der Heizzone I, II bei Grundheizlast benötigten Heizeinrichtungen HR in dieser Heizzone I, II zu bestimmen. Insbesondere kann der Gradient des zeitlichen Temperaturanstiegs zur Erreichung der Solltemperatur und/oder der Gradient des zeitlichen Temperaturabfalls (bei Betreiben der Heizzone I, II mit der Grundheizlast) ermittelt werden.The device 1, preferably the control device 3 of the device 1, is designed to detect the temporal temperature changes caused by activating / deactivating the heating devices HR and, based on this, the number of heating devices HR required to operate the heating zones I, II with the basic heating load in this heating zone I, II to be determined. In particular, the gradient of the temperature rise over time to reach the target temperature and / or the gradient of the temperature drop over time (when operating heating zones I, II with the basic heating load) can be determined.

Des Weiteren kann vorgesehen sein, die für die Grundheizlast verwendete Anzahl der aktiven Heizeinrichtungen HR zeitlich zu verändern, um die Grundheizlast aktuellen Gegebenheiten (beispielsweise einer veränderten Umgebungstemperatur) anzupassen. So kann beispielsweise die für die Grundheizlast verwendete Anzahl der aktiven Heizeinrichtungen HR um eins reduziert werden, wenn beim Erhöhen der Heizleistung gegenüber der Grundheizlast durch Zuschalten einer weiteren Heizeinrichtung HR (zweiter Betriebsmodus) die gemessene Ist-Temperatur im Bereich der Heizzone I, II die Solltemperatur ST um einen vorgegebenen Temperaturdifferenzwert für eine vorgegebene Zeitdauer überschreitet. In anderen Worten kann die Grundheizlast verringert werden, wenn ein temperaturbetragsmäßig oder zeitlich starkes Überschwingen bei der Temperaturregelung erreicht wird. So kann beispielsweise die Grundheizlast verringert werden, wenn der Temperaturdifferenzwert im Bereich zwischen 1°C und 5°C liegt, insbesondere 2°C, 3°C oder 4°C beträgt und/oder die die vorgegebene Zeitdauer im Bereich zwischen 30sec und 3min liegt, insbesondere 1min, 1,5min oder 2min oder mehr beträgt.Furthermore, the number of active heating devices HR used for the basic heating load can be changed over time in order to adapt the basic heating load to current conditions (for example, a changed ambient temperature). For example, the number of active heating devices HR used for the basic heating load can be reduced by one if, when the heating output is increased compared to the basic heating load by switching on a further heating device HR (second operating mode), the measured actual temperature in the area of heating zones I, II exceeds the target temperature ST exceeds a predetermined temperature difference value for a predetermined period of time. In other words, the basic heating load can be reduced if an overshoot in terms of temperature or time is reached in the temperature control. For example, the basic heating load can be reduced if the temperature difference value is in the range between 1 ° C and 5 ° C, in particular 2 ° C, 3 ° C or 4 ° C and / or the specified period of time is in the range between 30 seconds and 3 minutes, in particular 1 minute, 1.5 minutes or 2 minutes or more.

Ebenso kann das Verhältnis einer ersten Zeitdauer, bei der eine Heizzone oberhalb der Grundheizlast betrieben wird, zu einer zweiten Zeitdauer, in der die Heizzone unterhalb der Grundheizlast betrieben wird, herangezogen werden, um die Anzahl der bei Grundheizlast aktiven Heizeinrichtungen HR zu verändern. So kann beispielsweise ein Verhältnis der ersten Zeitdauer zur zweiten Zeitdauer durch die Steuereinrichtung 3 oder einen damit verbundenen Steuerrechner ermittelt und mit einem Schwellwert verglichen werden. Für den Fall, dass der berechnete Wert den Schwellwert unterschreitet, kann die Anzahl der bei Grundheizlast aktiven Heizeinrichtungen HR verringert werden, insbesondere um eine einzige Heizeinrichtung HR. Dabei kann das Zeitdauerverhältnis über einen Zeitraum von mehreren Schaltzyklen hinweg gemittelt und dieser gemittelte Wert für die Entscheidung der Veränderung der bei der Grundheizlast aktiven Heizeinrichtungen HR verwendet werden.The ratio of a first time period during which a heating zone is operated above the basic heating load to a second time period during which the heating zone is operated below the basic heating load can be used to change the number of heating devices HR active during the basic heating load. For example, a ratio of the first time period to the second time period can be determined by the control device 3 or a control computer connected to it and compared with a threshold value. In the event that the calculated value falls below the threshold value, the number of heating devices HR active during the basic heating load can be reduced, in particular by a single heating device HR. The duration ratio can be averaged over a period of several switching cycles and this averaged value can be used to decide the change in the heating devices HR active during the basic heating load.

Die Schaltmittel 4 können neben dem An- bzw. Abschalten der Energiezuführung zu den Heizeinrichtungen HR zudem zur Überwachung bzw. zum Monitoring der jeweiligen an ihnen angeschlossenen Heizeinrichtungen HR ausgebildet sein. So können die Schaltmittel 4 beispielsweise zur Überwachung der elektrischen Last bzw. der elektrischen Leistungsaufnahme der an ihnen angeschlossenen Heizeinrichtung HR ausgebildet sein. Aufgrund dieser Überwachungs- bzw. Monitoringfähigkeit kann beispielsweise erkannt werden, wenn die Heizeinrichtung HR keine oder nur eine geringe Heizleistung bereitstellt, was zu unzureichender Schrumpfleistung im Bereich des Schrumpftunnels 6 führt. Beispielsweise kann ein Überwachungs- bzw. Monitoringausgang des Schaltmittels 4 mit der Steuereinrichtung 3 gekoppelt sein und ein Fehlersignal abgeben, wenn keine oder nur eine geringe Heizleistung der Heizeinrichtung HR festgestellt wird. Zudem können die Schaltmittel 4 dazu ausgebildet sein, die Heizeinrichtung HR dauerhaft vom Stromnetz zu trennen, beispielsweise im Falle eines elektrischen Kurzschlusses. Des Weiteren können die Schaltmittel 4 zur Ansteuerung der Heizeinrichtung HR gemäß der Schwingungspaketsteuerung ausgebildet sein. Dabei wird, wie in Figur 4 gezeigt, im Gegensatz zur Phasenanschnittsteuerung die Heizeinrichtung HR nur in den Nulldurchgängen des zeitlichen Strom- bzw. Spannungsverlaufs geschaltet. Dadurch können Strom- und Spannungs-Transienten und damit Oberschwingungen weitgehend vermieden werden.In addition to switching the energy supply to the heating devices HR on and off, the switching means 4 can also be designed to monitor or monitor the respective heating devices HR connected to them. For example, the switching means 4 can be designed to monitor the electrical load or the electrical power consumption of the heating device HR connected to them. Because of this monitoring or monitoring capability, it can be recognized, for example, when the heating device HR provides no or only a low heating output, which leads to insufficient shrinkage output in the area of the shrink tunnel 6. For example, a monitoring or monitoring output of the switching means 4 can be coupled to the control device 3 and emit an error signal if no or only a low heating output of the heating device HR is detected. In addition, the switching means 4 can be designed to permanently disconnect the heating device HR from the power supply system, for example in the event of an electrical short circuit. Furthermore, the switching means 4 can be designed to control the heating device HR in accordance with the vibration packet control. As in Figure 4 shown, in contrast to the phase control, the heating device HR switched only in the zero crossings of the temporal current or voltage profile. In this way, current and voltage transients and thus harmonics can be largely avoided.

Die Schaltmittel 4 können insbesondere durch einen Halbleiterschütz, beispielsweise einen 2/3-phasigen Halbleiterschütz (RGC2/RGC3) des Herstellers Carlo Gavazzi gebildet werden. Der Halbleiterschütz weist beispielsweise einen Überspannungsschutz, Lastüberwachungsmittel, einen Alarmausgang und ggf. weitere Hilfskontakte auf.The switching means 4 can in particular be formed by a semiconductor contactor, for example a 2/3 phase semiconductor contactor (RGC2 / RGC3) from the manufacturer Carlo Gavazzi. The semiconductor contactor has, for example, overvoltage protection, load monitoring means, an alarm output and, if necessary, further auxiliary contacts.

Fig. 5 zeigt den zeitlichen Verlauf der elektrischen Leistungsaufnahme einer Vorrichtung 1 zur Beheizung des Schrumpftunnels 6 mittels der Heizeinrichtungen HR. Dabei zeigt der zeitlich stark schwankende, gezackte Kurvenverlauf K1 die elektrische Leistungsaufnahme einer Vorrichtung gemäß dem vorbeschriebenen Stand der Technik, bei dem die Grundheizlast sehr niedrig gewählt ist und die sämtliche übrigen Heizeinrichtungen stets gleichzeitig zur Regelung der Ist-Temperatur an- bzw. ausgeschaltet werden. Die darunter liegende Kurve K2 zeigt eine wesentlich geringere zeitliche Schwankungshäufigkeit, wobei die Leistung länger auf einem gewissen Leistungsniveau verbleibt. Zudem ist die Amplitude der Leistungsänderung wesentlich geringer. Dadurch können Leistungsschwankungen im elektrischen Stromnetz, aber auch die mechanische Belastung der Heizeinrichtungen durch häufiges Ein- und Ausschalten wesentlich reduziert werden. Zudem ist erkennbar, dass dadurch die verbrauchte elektrische Durchschnittsleistung der Vorrichtung 1 verringert werden kann, so dass auch die Energieeffizienz der Vorrichtung 1 gesteigert wird. Fig. 5 shows the time profile of the electrical power consumption of a device 1 for heating the shrink tunnel 6 by means of the heating devices HR. The jagged curve K1, which fluctuates strongly over time, shows the electrical power consumption of a device according to the prior art described above, in which the basic heating load is selected to be very low and all other heating devices are always switched on and off simultaneously to control the actual temperature. The underlying curve K2 shows a significantly lower frequency of fluctuations over time, with the performance remaining longer at a certain performance level. In addition, the amplitude of the change in power is significantly lower. As a result, power fluctuations in the electrical power network, but also the mechanical load on the heating devices due to frequent switching on and off, can be significantly reduced. It can also be seen that this can reduce the average electrical power consumed by the device 1, so that the energy efficiency of the device 1 is also increased.

Die Erfindung wurde voranstehend an Ausführungsbeispielen beschrieben. Es versteht sich, dass eine Vielzahl von Änderungen oder Abwandlungen möglich sind, ohne vom Umfang der beigefügten Ansprüche abzuweichen.The invention was described above using exemplary embodiments. It is understood that numerous changes or modifications are possible without departing from the scope of the appended claims.

BezugszeichenlisteList of reference symbols

11
SchrumpfvorrichtungShrinking device
33rd
SteuereinrichtungControl device
44th
SchaltmittelSwitching means
55
Transporteurcarrier
66th
SchrumpftunnelShrink tunnel
I, III, II
HeizzoneHeating zone
HRMR
HeizeinrichtungHeating device
STST
SolltemperaturTarget temperature

Claims (15)

  1. Method for operating an apparatus (1) for heat-shrinking a sheet-like material onto a group of individual packs, having at least one heating zone (I, II) with a plurality of electrical heating devices (HR), wherein the method comprises the following method steps:
    - sensing the actual temperature in the region of the heating zone (I, II) and comparing the actual temperature in the region of the heating zone (I, II) with a desired temperature (ST);
    - switching into a first operating mode by reducing the number of active heating devices (2, 2', 2") in the heating zone (I, II) to a predefined number of heating devices (HR) when the actual temperature (IT) in the region of the heating zone (I, II) has exceeded the desired temperature (ST), wherein the predefined number of heating devices (HR) was determined by taking at least one operating parameter into consideration; and
    - switching from the first operating mode into a second operating mode by increasing the number of active heating devices (HR) in the heating zone (I, II) in order to increase the actual temperature in the region of the heating zone (I, II) to the desired temperature (ST).
  2. Method according to claim 1, characterised in that the number of the active heating devices (HR) in the first operating mode is dependent on the desired temperature (ST) in the heating zone (I, II).
  3. Method according to claim 1 or 2, characterised in that the number of active heating devices (HR) in the first operating mode is equal to or greater than two.
  4. Method according to any one of the preceding claims, characterised in that the number of active heating devices (HR) in the second operating mode is greater by one than the number of the active heating devices (HR) in the first operating mode.
  5. Method according to any one of the preceding claims, characterised in that the number of active heating devices (HR) in the first operating mode is calculated by a control device (3), taking account of at least one operating parameter.
  6. Method according to any one of the preceding claims, characterised in that the number of the active heating devices (HR) in the first operating mode during the operation of the device (1) is calculated continuously or intermittently on the basis of operating parameters.
  7. Method according to any one of the preceding claims, characterised in that the number of the heating devices (HR) active in the first operating mode is determined by taking account of the temperature changes in the respective heating zone (I, II) incurred by the activating and/or deactivating of the respective heating devices (HR).
  8. Method according to claim 6 or 7, characterised in that the number of the heating devices (HR) active in the first operating mode is reduced by one if the actual temperature measured in the second operating mode in the region of the heating zone (I, II) exceeds the desired temperature (ST) by a predetermined temperature difference value for a predetermined period of time.
  9. Method according to claim 8, characterised in that the temperature difference value lies in the range between 1 °C and 5 °C, in particular 2 °C, 3 °C, or 4 °C.
  10. Method according to claim 8 or 9, characterised in that the predetermined period of time lies in the range between 30 seconds and 3 minutes, in particular 1 minute, 1.5 minute, or 2 minutes, or more.
  11. Method according to any one of claims 6 to 10, characterised in that the number of the heating devices (HR) active in the first operating mode is reduced by one, if the ratio of the period of time in which the apparatus (1) is in the second operating mode to the period of time in which the apparatus (1) is in the first operating mode falls below a threshold value.
  12. Method according to claim 11, characterised in that the ratio of the time periods is determined over several switching cycles.
  13. Method according to any one of the preceding claims, characterised in that the activation and deactivation of the heating devices (HR) takes place by means of switching means (4), wherein the switching means (4) monitor the electrical load incurred by these actions.
  14. Method according to any one of the preceding claims, characterised in that the activation and deactivation of the heating devices (HR) takes place by means of at least one switching device, which is configured for the switching of the heating devices (HR) in accordance with the principle of multicycle control.
  15. Apparatus for heat-shrinking a sheet-like material onto a group of individual packs, having at least one heating zone (I, II) with a plurality of electrical heating devices (HR), and a temperature sensor for determining the actual temperature in the region of the heating zone (I, II), wherein a control device (3) is provided which is configured for receiving information relating to the actual temperature in the region of the heating zone (I, II) and to arrange for switching the apparatus (1) from a first operating mode into a second operating mode, wherein switching means (4) are provided which interact with control device in such a way that a switch is made into a first operating mode, in that the number of the active heating devices (HR) is reduced to a predefined number of heating devices (HR) if the temperature in the region of the heating zone (I, II) has exceeded a desired temperature (ST), characterised in that the predetermined number of heating devices (HR) was determined taking at least one operating parameter into consideration, and thereby interact in such a way that switching takes place from the first operating mode into a second operating mode, in that the number of the active heating devices (HR) is increased in order to regulate the actual temperature in the region of the heating zone (I, II) is increased to the desired temperature (ST).
EP18717574.0A 2017-04-11 2018-04-10 Method for regulating the heat output of shrink-wrapping apparatuses and corresponding apparatus Active EP3609792B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PL18717574T PL3609792T3 (en) 2017-04-11 2018-04-10 Method for regulating the heat output of shrink-wrapping apparatuses and corresponding apparatus

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE102017107766.9A DE102017107766A1 (en) 2017-04-11 2017-04-11 Method and device for forming containers
PCT/EP2018/059096 WO2018189141A1 (en) 2017-04-11 2018-04-10 Method for regulating the heat output of shrink-wrapping apparatuses and corresponding apparatus

Publications (2)

Publication Number Publication Date
EP3609792A1 EP3609792A1 (en) 2020-02-19
EP3609792B1 true EP3609792B1 (en) 2021-09-15

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Application Number Title Priority Date Filing Date
EP18717574.0A Active EP3609792B1 (en) 2017-04-11 2018-04-10 Method for regulating the heat output of shrink-wrapping apparatuses and corresponding apparatus

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Country Link
EP (1) EP3609792B1 (en)
DE (1) DE102017107766A1 (en)
PL (1) PL3609792T3 (en)
WO (1) WO2018189141A1 (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102018132737A1 (en) * 2018-12-18 2020-06-18 Krones Aktiengesellschaft Process and shrink tunnel for shrinking thermoplastic packaging material onto articles

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3678244A (en) * 1971-06-18 1972-07-18 Paul W Worline Film shrinking tunnel utilizing hot air and water as heat transfer medium
DE2610385A1 (en) * 1976-03-12 1977-09-15 Riedhammer Ludwig Fa Ferrite sintering pusher furnace - with nitrogen flows in preheating and cooling zones at specified directions (NL 14.9.77)
GB2246110B (en) * 1990-12-07 1995-02-15 Balair Systems Ltd Method and apparatus for the packaging of products
US6394796B1 (en) * 1999-11-04 2002-05-28 Alan D. Smith Curing oven combining methods of heating
DE102010020957A1 (en) * 2010-05-19 2011-11-24 Khs Gmbh Shrink tunnel for applying shrink films, method for operating or controlling a shrink tunnel and production plant with a shrink tunnel
EP2776753A4 (en) * 2011-11-10 2016-08-31 Shawcor Ltd Apparatus containing multiple sequentially used infrared heating zones for tubular articles
DE102013215415A1 (en) * 2013-08-06 2015-02-12 Krones Aktiengesellschaft Method and apparatus for shrinking materials onto articles and / or to a collection of articles

Also Published As

Publication number Publication date
PL3609792T3 (en) 2022-02-07
WO2018189141A1 (en) 2018-10-18
EP3609792A1 (en) 2020-02-19
DE102017107766A1 (en) 2018-10-11

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