Process Control Engineering

Posted in: , on 22. Aug. 2011 - 18:50

Configuring production processes flexibly:

Process control engineering with distribution of responsibility

Klaus Gille, Managing Director, ZOZ & PARTNER GmbH (Fig. 7) and

Ms. Nora Crocoll, M.Eng. (University of Applied Sciences), Redaktionsbüro Stutensee (Fig. 8)


The fast and reliable production of products at consistently high quality is only possible with well-thought-through and transparent production processes. This is where a process control system comes into play. In the ideal scenario this happens on two levels: One level that shows the entire process including all individual production steps in an abstract way and the other level implements these specifications via PLC control, sensor and actuator technology. The abstracted definition “what needs to be done using what” without detailing “how to do something” yields great advantages in practical application. This text describes these by giving an example application used at the Amberger Kaolinwerke, Hirschau, Germany.

Kaolin is a soft white malleable mineral which consists mainly of finely grained, plate-like particles and is used primarily in paper and porcelain manufacturing. Because of its whiteness and plasticity Kaolin is particularly well suited for use as a filler or extender, as a ceramic and fire-proof raw material or as a pigment. The Amberger Kaolinwerke Eduard Kick GmbH & Co. KG (AKW) based in Hirschau, Germany, has specialised in the quarrying of Kaolin, but also for silica sand and feldspars, and refines these minerals for industrial use (Fig. 1).

On a very large and extensive production site the raw soil is separated in different parts of the plant into the three pure industrial mineral types, and is then processed or refined in various wet-mechanical processing steps, such as sieving, filtering, cleaning or mixing. For more than a decade the smooth running of production has been ensured by process control technology and production log solutions provided by Zoz & Partner GmbH, Karlsruhe.


zoz_bild1

Fig 1:

The Amberger Kaolinwerke Eduard Kick GmbH & Co. KG based in Hirschau, Germany,

have specialised on quarrying for Kaolin, but also mine silica sand and feldspars,

and process these minerals for industrial use. (Photo: AKW)



Separating planning and execution levels has advantages

What has come about is a process-oriented, formula-controlled mixing control system with standardised interface at the control level that could be applied in many areas of the processing industry. The mixing control system has grown over the years in line with the requirements of the production plant itself. Freddy Schlosser (Fig. 2), Head of Development at Zoz & Partner GmbH, sums up his experiences: “Over the years we have realised many such projects. Practice has shown that the most difficult part is to convince the customer of the benefits of a process control technology with a rigorous distribution of responsibilities. “This separation effectively means that within project management, orders are defined at management levels which represent recurring tasks in an abstracted way, e.g. “Dose quantity from a predefined source into mixer”. These specifications are initially completely independent of the technology that is executing the task. It does not matter to the model whether the order is performed manually or in automated fashion, and if automated, which control is being used.

The specifics of these orders are then transmitted to the control level via a uniformly defined, logical interface, which has to implement these specifications technically, for example with a PLC control that triggers the respective pumps and valves so as to mix the desired quantities from predefined sources.


zoz_bild2_schlosser_freddy

Fig. 2:

Freddy Schlosser, Head of Development at ZOZ & PARTNER GmbH:

"Practice has shown that the most difficult part is always to convince the customer of the benefits

of a process control technology with a rigorous distribution of responsibilities.
(Photo: ZOZ)[/SIZE]



A significant advantage of the rigorous separation is that each area is able to concentrate on its core competences. The mechanic or PLC programmer does not have to deal with the process per se, while the technician at the other end (i.e. chemist, food expert or similar) does not need to know the processes at control level in detail when he/she wants to set up new process flows. Due to ready-made modules the flexible adjustment to different plant sections of the production site is greatly facilitated and the technologist is able to test new recipes easily and directly in the plant. Thanks to graphics support in the process modeller the configuration is also completed quickly (Fig. 3).


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Fig. 3:

Thanks to graphics support in the process modeller

the configuration is completed quickly
(Graphic: ZOZ)



Further benefits come about when new software is tested or during the start-up of plants. Since it is independent of the process model, whether the orders issued are executed by way of automation or manually at control level, the commissioning of a plant section by manual operation is therefore easy to accomplish. To test new program elements the PLC control can simply be replaced by test software.

The system grows in line with its tasks

As in every extensive plant in the processing industry it is also natural for the Amberger Kaolinwerke to have some plant sections or production lines converted or updated over the years. In connection with these the mixing control system is also always being integrated for the planning of mixing orders and for the coordination of manufacturing processes. “Obviously not every plant section performs the exact same tasks as the other sections, so we have also gradually added new components to our software”, explains Mr. Schlosser. An important point that has been added recently is the automated data capture. “Where process data exist in digital form, for example for process cycle times, it is of course sensible to adopt these in the mixing control system in automated form. This generates fewer errors than through manual input. “Another addition is the linking of more and more areas into the overriding ERP system. For instance, individual production orders can now be triggered directly from SAP. At the same time capacity planning from SAP is also possible, as the mixing control system knows the entire processes including their exact flows and production cycles in detail. The simple integration into the existing automation environments is possible thanks to standardised OPC interfaces.

Managing process data reliably

Over the years there have also been expansions in the area of data storage. In addition to standard functions for the general recording and archiving of process-relevant data for quality assurance, traceability or process optimisation purposes, new and growing demands, for example due to TÜV-imposed environmental regulations, were put on the mixing control system. The system also stores all relevant data in connection with the above and can be modified to suit the changing requirements (Fig. 4).


zoz_bild4

Fig 4:

In addition to standard functions for the general recording and archiving of process-relevant data

for quality assurance, traceability or process optimisation purposes, growing demands, for example

due to TÜV-imposed environmental regulations, were put on the mixing control system.

The system also stores all relevant data in connection with the above and can be modified to suit

the changing requirements.
(Graphic: ZOZ)



At the Amberger Kaolinwerke there are always process steps that necessitate interim and end products being checked in the laboratory, e.g. for a chemical or mineralogical analysis, to test grain size distribution or to determine pH value, viscosity, abrasion or humidity. Although laboratory processes cannot completely be automated, they can, however, be tied in with the mixing control system. Laboratory tests are now initiated by the system and reversely, the test results can automatically be stored in the mixing control system matched to the respective batch.

A new barcode system introduced to the plant prevents misunderstandings. This way the batch to be dispatched can be allocated to the right truck.

A new barcode system introduced to the plant prevents misunderstandings. This way the batch to be dispatched can be allocated to the right truck. “With the barcode solution we are taking an important step towards a fully automated production, 24 hours a day, seven days a week” says Freddy Schlosser (Fig. 5).


zoz_bild5

Fig 5:

Via the barcode system the batch to be dispatched can be allocated to the right truck.

With this barcode solution the whole plant is taking a step towards fully automated production.


(Photo: AKW)



Flexible adjustability

The essential goal for the mixing control system was, right from the start, that it could be used in different plant sections at the Hirschau location, and that it was flexible enough to adjust to different work flows and plant configurations, without outside help. Bernhard Neudecker, M.Eng. (Fig. 6), Head of Production at Amberger Kaolinwerke, outlines the benefits: “For us the clear advantage lies in the separation between operational processes and the implementation at the control level. The modeller enables us to set up new processes with flexibility, but without any programming effort. At the same time the mixing control system can easily and universally be used in the various plant sections at our production premises.


zoz_bild6_neudecker_bernhard

Bild 6:

Bernhard Neudecker, M.Eng. Head of Production at Amberger Kaolinwerke:

“For us the clear advantage lies in the separation between operational processes

and the implementation at the control level. The modeller enables us to set up new

processes with flexibility, but without any programming effort. The mixing control system

can at the same time be used easily and universally in all plant sections. “
(Photo: AKW)



But more than that, the modeller is not just good for the fast configuration of new workflows. Thanks to its user-friendliness across a graphical surface it can also be used for documentation workflows. For example, with the modeller a plant can be documented, or rather the modeller becomes the knowledge store where maintenance processes are for instance documented.

With the modeller, users can adjust the mixing control system to suit their own requirements. On the off-chance that problems should arise that require the expertise of Zoz & Partner; these problems can quickly be solved thanks to remote access. But there is hardly any need for this, as Mr. Neudecker attests: “We need practically no assistance with the running system and should there be an exception to this rule we are able to - thanks to the remote access - quickly and without expensive travel, solve the problem. The staff of Zoz & Partner literally only come by in case of commissioning or to discuss new tasks. We are extremely satisfied, not only with the mixing control system itself, but also with the after-sales service. This is, after all, mirrored in our cooperation which goes back more than a decade. “

About Amberger Kaolinwerke

Die Amberger Kaolinwerke Eduard Kick GmbH & Co. KG sind Teil der international ausgerichteten Quarzwerke Gruppe. Die Hauptabsatzmärkte der Quarzwerke Gruppe sind insbesondere die Papier-, Glas-, Gießerei-, Keramik-, Kunststoff- und der Gummi-Industrie sowie in Farben und Lacken und bauchemischen Produkten.

Innerhalb dieses starken Unternehmensverbundes sind die Amberger Kaolinwerke der Spezialist für Kaolin- und Feldspat-Anwendungen in den internationalen Märkten. Der Unternehmensschwerpunkt liegt in der Gewinnung, Aufbereitung und Veredelung dieser Industriemineralien.

Weitere Informationen zum Thema finden Sie unter: http://www.quarzwerke.com/home


About ZOZ & PARTNER GmbH

Those who want to work more cost-effectively and more efficiently will have to identify workflows, control them in a targeted manner, document them methodically and be ready to reorganise them at any time. ZOZ & PARTNER GmbH based in Karlsruhe has the right solutions for these problems. The owner-managed software company tackles all issues with regard to project or product-related, operational, technical or commercial processes and process environments. Based on experience gained in projects in a variety of sectors the company from Karlsruhe develops in the area of Business Process Management (BPM) fully matured, multi-functionally applicable software tools for a diverse range of task scenarios within product life cycle and process control technology.


The Authors:


zoz_bild7_gille_klaus

Fig: 7:

Klaus Gille, Managing Director

ZOZ & PARTNER GmbH

zoz002_bild8_crocoll_nora

Fig. 8:

Nora Crocoll, M.Eng. (University of Applied Sciences)

Redaktionsbüro Stutensee



For more information, please visit:

https://edir.bulk-online.com/oldedir...oz-partner.htm

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