1st Quarter 2017, Electrical switching & drive systems & components
Grain must go through several production stages from the field to the bakery while it is milled to flour and finally lands on the consumer’s table as bread or cake. This chain of processes can be seen in action on a visit to the Nestelberger hulling mill and silo at Perg, Austria, which now uses an automation solution incorporating Vipa and Yaskawa components. After the harvest, the silos at the hulling mill are filled with organic grain. “We have about 2500 tons of spelt, wheat, barley and oats in 24 storage cells,” explains Peter Pilsl, who is responsible for production at the mill.
However, before this stage is reached, the cereal grain must undergo several processing steps. The grain is conveyed to the mill, where it is cleaned and weighed and falls back down onto a conveyor, from where it is hulled and conveyed up to silos for storage. In-depth knowledge of the overall process is indispensable for optimum automation of a system of this size.
The mill operator can adjust all parameters with Zenon software from Copa Data. In the first step the grain type is selected. The desired process – hulling, storage or filling – can then be easily selected by means of a graphic with a few clicks. Once the desired path for the grain has been set, the system operator initiates the process with the start button and the mill is put into operation. The mill operator can run the mill alone in fully automatic mode.
The reason that a complex system like this can be operated in such a simple manner lies in the automation components employed. Andreas Stingeder from the electrical contractor, Mesa, says that the solutions from Vipa and Yaskawa proved to be best suited to the projects right from the outset. “In the course of time the range of components requested from us became more and more comprehensive. Initially we were only talking about a controller. After several consultations we recognised that we could offer more interfaces,” adds Christian Karl, product manager, drives and motion at Vipa Elektronik-Systeme.
“At the beginning of the project the customer was not entirely clear about the degree of automation needed. The full extent of automation only became apparent over time. Now we are employing virtually the full range of products of Vipa Elektronik-Systeme, from Vipa and Yaskawa components to Zenon. The advantage is that everything is drawn from one source. Above all, the customer was convinced by the level of service,” says Stingeder.
The mill consists of two parts. On the one side is the silo for storing the grain and on the other side the hulling machine. Both of these are controlled by a SLIO CPU 015 with memory expansion. The controller is thus responsible for all motors of the conveyor systems – vertical and horizontal – as well as screw conveyors, dosing valves, fill-level monitoring and the contact detectors of the slide valves. In addition, the controller is equipped with a coupling via Ethernet for the visualisation via Zenon.
Communications are via Profibus, although the Yaskawa frequency inverters are compatible with all standard bus systems. A total of three Yaskawa V1000 frequency inverters are used to control the drives. The frequency inverters of this series are impressive, not only due to their small size, but also on account of their extremely robust electronics and high performance levels. “If you have power cuts or load shedding following an emergency stop there is no problem at all,” Stingeder adds. “The ruggedness of these frequency inverters can be attributed to the extremely well-dimensioned power elements with considerable reserves – they have to endure a lot,” Karl adds. For problems occurring in operation of the system, Stingeder has incorporated text-based error messages in the visualisation. It can be seen at a glance where an error has occurred and the system operator immediately knows the score.
“Vipa and Yaskawa products were the ideal solution for this project; but the outstanding components themselves are only half the story. If I have any questions I just call Vipa Elektronik-Systeme and receive immediate answers and suggestions for solutions,” Stingeder concludes.
Ultimately there will be a remote mainten-ance solution which will be implemented with eWON. This will enable the management of the Nestelberger hulling mill to retrieve production data and system status via the Internet or mobile device.
For more information contact Jaco Taljaard, Yaskawa Southern Africa, +27 (0)11 608 3182, firstname.lastname@example.org, www.yaskawa.za.com