Heating device, bottle production plant, and method for operating a heating device

Abstract

The invention relates to a heating device (3), in particular for plastic preforms (1) in a stretch blow-moulding machine, comprising a plurality of radiant heaters (5) arranged along a heating section. According to the invention, the radiant heaters (5) are each assigned readable means containing individual data, and a control unit is designed to capture the individual data. The invention also relates to a bottle production plant comprising the heating device (3) and to a method for operating a heating device (3).

Description

[0001] Description

[0002] Heating device, bottle manufacturing plant and method for operating a heating device

[0003] The invention relates to a heating device, particularly for plastic preforms in a stretch blow molding machine, comprising a plurality of heaters arranged along a heating section. The invention further relates to a bottle production system for forming bottles from plastic preforms, comprising a feeder, the heating device, and a blow molding module downstream of the heating device. Finally, the invention also relates to a method for operating a heating device.

[0004] High-quality PET (polyethylene terephthalate) bottles can be manufactured using stretch blow molding, offering excellent performance characteristics and low weight, thus requiring minimal material usage. Stretch blow molding machines are widely used and are particularly suitable for the production of large quantities of PET bottles. Low production and material costs, coupled with high throughput, are particularly important when the bottles are intended as disposable products for single use.

[0005] It should also be noted that a particularly efficient process also contributes to the reduced use of raw materials and energy, and PET bottles are fully or almost fully recyclable. This also offers the advantage that common disposable PET bottles have an extremely low weight and can be easily shredded before recycling, resulting in a particularly small transport volume.

[0006] In a two-step process, plastic preforms are first produced by injection molding and then cooled. The resulting plastic preforms are easy to handle, store, and transport. For the stretch blow molding process, the cold plastic preforms are separated from a chute, for example, and fed into the heating device to be heated to a temperature suitable for the forming process.

[0007] Heating devices for plastic preforms in a stretch blow molding machine are known, for example, from EP 2 390 083 B1, EP 2 377 668 B1, EP 2 390 082 B1 and DE 10 2014 108676 A1.

[0008] For the basics of stretch blow molding, especially of PET bottles, please refer to “Blow molding of hollow plastic bodies”, M. Thielen, K. Hartwig, P. Gust, 2nd updated edition 2020 (ISBN 978-3-446-45552-8), page 149 ff.

[0009] Tubular infrared heaters are typically used for heating devices. These comprise an ohmic heating element in a quartz glass tube, which can be formed, for example, by a heating coil.

[0010] From the aforementioned prior art, it is known to optimize the heating process with the heating device. For this purpose, for example, the position of the heaters can be varied, particularly to allow adaptation to preforms of different sizes. The heat input can also be varied along the heating section.

[0011] A typical heating device for plastic preforms in a stretch blow molding machine uses a large number of, for example, 200 heaters. Several heating modules can be provided, each consisting of a group of several heaters arranged together. Tubular infrared heaters can, for example, be arranged horizontally one above the other in a heating module.

[0012] Due to the large number of heaters, varying heat outputs between the individual heaters can be compensated to a certain extent. This is especially true if an actual temperature is detected by sensors or similar. In practice, the function of the individual heaters can be checked by a simple continuity test. If a heater fails, it must then be determined whether it needs to be replaced at short notice as part of unscheduled maintenance or whether the remaining heaters can achieve sufficiently strong and even heating. Scheduled or unscheduled maintenance may be necessary, for example, if several heaters are defective; the typical operating life of a heater can be around 3,500 hours.

[0013] The invention is based on the object of providing a heating device which can be operated particularly efficiently and reliably.

[0014] Furthermore, a bottle production plant for forming bottles from plastic preforms with a heating device and a method for operating a heating device are to be specified.

[0015] The subject matter of the invention and the solution to the problem are a heating device according to claim 1, a bottle manufacturing plant according to claim 11 and a method for operating a heating device according to claim 12.

[0016] According to a first aspect, the invention thus relates to a heating device, in particular for plastic preforms in a stretch blow molding machine, comprising a plurality of radiant heaters arranged along the heating section. According to the invention, the heating device is characterized in that each of the radiant heaters is assigned readable means with individual data, and in that a controller is configured to record the individual data. Based on the individual data, specific information for the individual radiant heaters can be taken into account, which information is either a direct component of the individual data or can be determined in a database or the like based on the individual data. Comparison with database information can, of course, also be carried out decentrally, for example, cloud-based.

[0017] Depending on the design of the readable means, it is conceivable, for example, that the operating time of the radiant heaters or other information relevant to the life cycle can be recorded directly by the control system.

[0018] Additionally or alternatively, according to a preferred embodiment of the invention, the individual data for each radiant heater includes at least one individual identifier. The individual radiant heaters can then be identified using the individual identifier, whereby, for example, specific parameters such as the operating time of a radiant heater can be determined, logged, or read out not on the individual radiant heater itself, but in a central control system.

[0019] With an individual identifier, a unique assignment is possible for each radiant heater, whereby specific properties for each radiant heater can then be stored, logged, recorded and retrieved in a central control system.

[0020] For example, it is then possible to precisely record how long individual heaters are in operation on the heating device, so that the state of wear, remaining service life and other properties can be determined for each individual heater based on this information.

[0021] In addition to the operating time itself, other specific information can also be stored. For example, depending on the design of the control and activation of the individual heaters, the power and / or ambient temperature of each heater can also be logged, although such parameters can also influence the expected service life. Of course, other conditions during the operation of the heating device can also be taken into account in such recording and, if necessary, modeling the expected service life for each individual heater.

[0022] In addition to predicting or estimating the remaining operating time, it is also possible to modify the operation of each radiant heater based on the operating time or other specific parameters. For example, the collected data can also be used to adjust the current and voltage control of individual radiant heaters if the resistance and / or other relevant parameters for heat generation change over time.

[0023] Depending on the requirements, such an adaptation can aim at optimizing the radiation output and / or optimizing the service life.

[0024] For example, to optimize service life, it is also conceivable that individual heaters be deployed at different positions within the heating system during their life cycle, where different operating conditions prevail. For example, to extend service life, they can also be operated in a more cooled area or in a section with lower energy consumption, resulting in reduced radiant output.

[0025] With regard to maintenance measures, it may also be appropriate to apply different loads to individual heaters, taking specific life cycle information into account. For example, if scheduled maintenance is to be postponed or the goal is to achieve the longest possible maintenance intervals, heaters with a short remaining life expectancy can be subjected to less load, i.e., generally operated at a lower power level, than heaters with a long life expectancy.

[0026] By then adjusting the control of the various radiant heaters, a compromise can be found between sufficient and even heating on the one hand and particularly maintenance-friendly operation on the other.

[0027] According to a preferred embodiment of the invention, an electronic module with a memory and a communication interface is each assigned to the radiant heaters as a readable means. The individual identifier can then be stored in the memory. The communication interface can be set up in particular for connection to a bus system and / or for wireless communication. In a bus system, the design also makes it easy to spatially assign them based on the wiring. In the case of wireless communication, however, it is advantageous if the spatial position of each radiant heater in the heating device is known through suitable identification. If necessary, when a new radiant heater is installed, the individual identifier can be read out and then manually assigned to a specific position in the heating device.

[0028] The electronic module provided for each radiant heater can be designed differently. As already explained, in addition to providing a suitable communication interface, it is advisable to issue a unique identifier for unique identification. Based on this unique identifier, relevant life cycle information can then be determined by a central control system.

[0029] In principle, with a more complex design of the electronic module, it is also possible for the corresponding information to be determined and then stored directly by the electronic module itself.

[0030] For example, it is then possible for the actual operating hours and / or other relevant data to be stored and accessed directly in each electronic module assigned to a specific radiant heater. Even if a radiant heater is not monitored and logged by a central control system, this relevant information is always retained and can be evaluated.

[0031] As an alternative, it is also conceivable that monitoring could be carried out at least partially centrally, but specific parameters could be stored in the memory of the electronic module. Even then, the relevant information would always remain directly linked to the assigned radiant heater.

[0032] According to a further aspect, the electronic modules can each have a measuring device, for example, to measure at least one parameter such as current, voltage, and / or power. Furthermore, the measuring device can also be equipped with at least one sensor, for example, for temperature, pressure, vibration, or the like. Depending on the design, the processing and / or storage of measured values ​​can then be performed by the electronic module itself or by an external controller to which the electronic modules are jointly connected.

[0033] Of course, the described measures of local and central recording and administration can also be combined as desired.

[0034] According to a possible development of the invention, the electronic modules are each integrated into the associated radiant heater. The electronic module is then an inseparable component of the radiant heater. However, this can be disadvantageous in that the radiant heater must be manufactured and supplied with such an electronic module from the outset, with the electronic module then being intended for a single use over the lifetime of the radiant heater.

[0035] Alternatively, the heaters can also be equipped with a connection base, with the associated electronic module designed to be connectable to the connection base or connected to it when ready for use. Even if they are to be disposed of together, the heater and electronic module can then be manufactured separately and subsequently assembled.

[0036] In principle, however, it is also possible for the electronic module to be used multiple times. If the electronic module in such a variant only has an individual identifier, this identifier can be assigned to a new heating module in a corresponding database upon replacement. Especially if specific information is recorded and stored in the electronic module itself, resetting or overwriting existing information is also useful.

[0037] According to a preferred embodiment of the invention, at least one power supply unit is provided for the radiant heaters, wherein a plurality of radiant heaters are each connected to the power supply unit with a separate connecting cable.

[0038] Furthermore, it can be provided that several heating modules are each formed by a group of several jointly arranged heating conductors. Each heating module can, for example, have between 6 and 15, in particular 9, heaters arranged parallel to one another, which are often aligned horizontally.

[0039] In particular, it can be provided that a power supply unit is provided for the radiant heaters of a heating module, which in practice is also referred to as a heating controller.

[0040] According to a preferred embodiment of the invention, the radiant heaters are each designed as tubular infrared heaters. According to a conventional design, such infrared heaters preferably have a tubular casing made of quartz glass and an ohmic heating element arranged thereon. A heating coil, for example, can be provided as the ohmic heating element.

[0041] The invention also relates to a bottle production system for forming bottles from plastic preforms, comprising a feeder for the plastic preforms, the heating device described above, and a blow-molding module downstream of the heating device. The blow-molding module is preferably designed as a stretch blow-molding module.

[0042] Finally, the invention also relates to a method for operating a heating device, which is particularly configured as described above. The heating device comprises a plurality of radiant heaters arranged along a heating path. According to the invention, individual life cycle information is recorded for each of the radiant heaters. This can, in particular, be an operating time, a cumulative power output, etc. Corresponding life cycle information can be recorded and, if necessary, stored in a central controller or in electronic modules; reference is made to the explanations of the heating device itself.Within the scope of the method, it is preferably provided that the life cycle information is analyzed by an electronic evaluation device, wherein at least one method adaptation is carried out on the basis of the evaluation of the life cycle information, wherein the method adaptation comprises at least one of the following steps:.

[0043] Changing the position of individual heaters in the heating device;

[0044] Determining modified operating conditions for individual heaters depending on the specific life cycle information, for example to compensate for wear and / or to enable a longer operating period;

[0045] Determination of the operating time until planned maintenance and / or adjustment of operating conditions depending on the operating time until planned maintenance;

[0046] Defining specific maintenance measures;

[0047] Tracing a production batch for at least one of the heating elements and determining changed operating conditions for at least one other heating element of the same production batch.

[0048] As already explained, the position of individual heaters can be changed in order to ensure optimal service life and optimal utilization of the heaters through the various arrangements within the heating device.

[0049] The entire process can also be optimized by determining optimal operating conditions for individual radiant heaters based on specific life cycle information. The modified operating conditions can, for example, be designed to compensate for a certain amount of wear or to operate the individual radiant heaters in a mode adapted to their operating time. Since specific information is ideally known for all radiant heaters, it is possible to estimate when scheduled maintenance should be performed even during ongoing operation using simulation or prediction. This allows the current actual status of the system to be taken into account, resulting in a significant optimization compared to fixed maintenance intervals.

[0050] With fixed maintenance intervals, there is a risk that frequent unplanned maintenance will be necessary if the scheduled maintenance intervals are too long. Frequent scheduled maintenance, on the other hand, results in unnecessary effort and unnecessarily long downtime.

[0051] Individually scheduled maintenance also offers the advantage of being able to choose the exact time to ensure sufficient specialist personnel are available. Personal and / or operational aspects can even be taken into account if necessary.

[0052] When scheduling scheduled maintenance, it's also possible to deliberately adjust operating conditions. For example, if a maintenance interval needs to be postponed due to a lack of personnel and / or parts, radiant heaters with a short lifespan can be operated particularly carefully to avoid a sudden outage.

[0053] Furthermore, specific maintenance measures can be defined based on lifecycle information. For example, specific heaters expected to fail in the near future can be specifically replaced, preventing them from having to be replaced during unplanned maintenance during normal operation.

[0054] However, other specific maintenance measures can also be determined based on the life cycle information. For example, depending on their operating life, a more detailed inspection may be required for individual heaters, even if they are not yet scheduled for replacement. A more detailed inspection may include, for example, a visual inspection, an electrical measurement, or a further analysis.

[0055] Within the scope of the invention, it is also possible for a production batch to be traced back for at least one of the heating elements. It can then also be provided to define modified operating conditions for at least one other heating element of the same production batch. If, for example, a heating element exhibits unexpected behavior and / or a certain behavior occurs in several heating elements of a

[0056] production batch, adjustments may be appropriate for other heating elements of the same production batch. If, for example, a particular susceptibility to errors is identified, other heating elements of the same production batch can be operated in a less stressful operating mode and / or replaced as a precautionary measure. Opposite adjustments are of course also conceivable if a particularly high level of wear resistance is identified for a production batch. In principle, the determination of the production batch can also be used to optimize the manufacturing process of the heating elements, where necessary. A comparison can also be made with information recorded during production. In addition to the production batch, other comparable basic information about the heating elements, such as a manufacturer ID, a production date, or similar, can also be evaluated.

[0057] The invention is explained below with reference to the figures. They show:

[0058] Fig. 1 a bottle production line for forming bottles from plastic preforms,

[0059] Fig. 2 shows a heating device of the bottle production plant according to Fig. 1 in a sectional view,

[0060] Fig. 3 is a schematic view of the connection of several radiant heaters. Fig. 1 is a schematic view of a bottle production line for forming bottles from plastic preforms 1. The plastic preforms 1 are fed by a feeder 2 to a heating device 3 and there transferred to a conveyor 4 in the manner of a revolving chain (see also Fig. 2). The heating device 3 has a plurality of radiant heaters 5 arranged along a heating section in order to heat the plastic preforms 1, initially fed at ambient temperature from the feeder 2, to a temperature suitable for forming.

[0061] The plastic preforms 1 are then transferred to a known blow molding module 6 and formed into bottles there.

[0062] The heating device 3 has a large number of, for example, approximately 200 radiant heaters 5. Figure 1 shows several heating modules 7, each formed by a group of several jointly arranged radiant heaters 5. Figure 2 shows a section through the heating device 3, with nine horizontally aligned radiant heaters 5 arranged one above the other being shown as an example in a heating module 7. The radiant heaters 5 are each designed as tubular infrared heaters.

[0063] According to the invention, it is provided that the radiant heaters 5 are each assigned readable means with individual data and that a control system is set up to record the individual data.

[0064] For this purpose, according to Fig. 3, it can be provided that each of the radiant heaters 5 is assigned an electronic module 8. It is indicated purely schematically that the electronic modules 8 each have a memory 9 and a communication interface 10. In the illustrated embodiment, the communication interface 10 is configured, by way of example, for connection to a bus system with bus lines 11 and a bus controller 12. Additionally or alternatively, the communication interface 11 can also be configured for wireless communication.

[0065] At least one identifier is stored in the memory 9, which uniquely identifies the respective assigned radiant heater 5. In this context, Fig. 3 shows only the schematic structure. The electronic modules 8 can be integrated into the respective assigned radiant heater 5 or arranged separately. In a separate arrangement, for example, it can be provided that the radiant heaters 5 have a connection base, with the respective assigned electronic module 8 being connected to the connection base.

[0066] The electronic modules 8 can also each have at least one measuring device, for example, to determine electrical parameters such as current, voltage, and power. Furthermore, sensors for temperature, pressure, vibration, or the like can also be integrated, with data processing being possible directly in the electronic module 8 or via the bus system.

[0067] The bus controller 12 is connected to a main controller so that further evaluation, recording and logging can also take place there.

[0068] By identifying the individual heaters 5 using the electronic module 8, specific life cycle information can be recorded and evaluated for each individual heater 5, allowing the remaining service life, wear characteristics, and other specific parameters to be determined or estimated. This makes it possible to operate the individual heaters 5 differently, interchange them, replace them, or inspect them individually as needed.

[0069] In particular, the individual radiant heaters 5 are connected to a power supply unit (not shown) via separate connecting lines 13. For example, a separate power supply unit can be provided for the radiant heaters 5 of each heating module 7. The power supply unit can be used to individually control the various radiant heaters 5, thereby enabling, in particular, a precisely adjusted power output. The at least one power supply unit is also connected to the main control system, whereby the individual radiant heaters 5 can also be controlled depending on the specific life cycle information. List of reference symbols:

[0070] 1 plastic preform

[0071] 2 Feed 3 Heating device

[0072] 4 Means of transport

[0073] 5 radiant heaters

[0074] 6 Blow module

[0075] 7 Heating module 8 Electronic module

[0076] 9 memory

[0077] 10 Communication interface

[0078] 11 bus lines

[0079] 12 Bus controller 13 Connection cable

Claims

Patent claims 1. Heating device (3), in particular for plastic preforms (1) in a stretch blow molding machine, with a plurality of radiant heaters (5) arranged along a heating section, characterized in that readable means with individual data are assigned to the radiant heaters (5) and that a control is set up to record the individual data.

2. Heating device (3) according to claim 1, characterized in that the individual data for each radiant heater (5) comprise an individual identifier.

3. Heating device (3) according to claim 1 or 2, characterized in that an electronic module (8) with a memory (9) and a communication interface (10) is assigned to each of the radiant heaters (5) as a readable means.

4. Heating device (3) according to claim 3, characterized in that the communication interface (10) is configured for connection to a bus system and / or for wireless communication.

5. Heating device (3) according to claim 3 or 4, characterized in that the electronic modules (8) each have at least one measuring device.

6. Heating device (3) according to one of claims 3 to 5, characterized in that the electronic modules (8) are each integrated into the associated radiant heater (5).

7. Heating device (3) according to one of claims 3 to 5, characterized in that the radiant heaters (5) have a connection base, wherein the respectively associated electronic module (8) is designed to be connectable to the connection base.

8. Heating device (3) according to one of the preceding claims, characterized in that at least one power supply unit is provided for the radiant heaters (5), wherein a plurality of radiant heaters (5) are each connected to the power supply unit with a separate connecting line (13).

9. Heating device (3) according to one of the preceding claims, characterized in that a plurality of heating modules (7) are each formed by a group of a plurality of jointly arranged radiant heaters (5).

10. Heating device (3) according to one of the preceding claims, characterized in that the heating radiators (5) are each designed as tubular infrared radiators.

11. Bottle production plant for forming bottles from plastic preforms (1) with a feed (2), with a heating device (3) according to one of the preceding claims and with a blow module (6) downstream of the heating device.

12. Method for operating a heating device (3), in particular according to one of claims 1 to 10, with a plurality of radiant heaters (5) arranged along a heating section, characterized in that individual life cycle information is recorded for each of the radiant heaters (5).

13. Method according to claim 12, characterized in that the Life cycle information is analyzed by an electronic evaluation device, wherein at least one process adaptation is carried out based on the evaluation of the life cycle information, wherein the process adaptation comprises at least one of the following steps: a. Changing the position of individual radiant heaters (5) in the heating device (3); b. Determination of modified operating conditions for individual radiant heaters (5) depending on the specific life cycle information; c. Determination of the operating time until planned maintenance and / or adjustment of operating conditions depending on the operating time until planned maintenance; d. Determination of specific maintenance measures e. Tracing a production batch for at least one of the heating elements and determining modified operating conditions for at least one further heating element of the same production batch.

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