July 1, 2010
by Rudolf Peter
The grain terminal in Wil, the largest autonomous grain facility of its kind in eastern Switzerland, has been in operation for more than 50 years and features two storage silos that date back to 1957 and 1977.
Before its most recent renovation, it had been more than 20 years since major investment had been made at the facility and in its technical equipment.
A few years ago, Swiss Railways (SBB), as the builder of the older storage silos, withdrew from the company. Today, the company is owned by private shareholders, including various Swiss grain trading companies that must think ahead and keep the storage and handling systems up to date. The grain terminal in Wil is of critical importance to Switzerland as it still holds, among other products, 20,000 tonnes of grain as mandated by the government for ensuring grain supplies to the population in times of crisis.
FUTURE REQUIREMENTS IDENTIFIED
For safe and reliable storage of grain, an intact building infrastructure and well-functioning conveying systems are vital. Just as essential, however, are carefully organized and safe production processes. The very extensive installation, with over 220 storage bins and complex receiving (intake), cleaning, storage, turnover and load-out facilities, must permanently allow clear and manageable planning. In a plant with automated processes, the operating personnel must at all times be fully informed about the current conditions with regard to storage, product movements and running processes.
After more than 20 years of operation, the need to renew the complete automation system at the Wil facility became urgent. The partners for solving this task were found in the specialists of Uzwil, Switzerland-based Buhler AG. For Silo AG Wil, it was important to utilize the advantages of automation technology and also to generate added value for its plant. The specific targets and requirements were planned in very close cooperation with a smooth and successful implementation thereafter.
The automation tasks are now fulfilled by the newest generation of Buhler’s WinCoS.r2 process automation system. It is equipped with a multi-user process control system based on client-server technology, a centralized database, and an active stand-by computer system. The heart of the subordinated control level is a Simatic S7 PLC system with bus systems and about 1,900 input/output points.
The new software supports the personnel in all possible ways, allowing optimal utilization of the available plant technology and thereby improving product safety and process reliability. Function modules, such as customer and supply management, product and bin management, lot and inventory management, automatic job processing for all incoming and outgoing products and movements within the plant, comprehensive reporting options, event and alarm logging, and the audit log constitute the backbone of the automation system.
The zoom-in graphic process visualization feature informs users about all process details in line with the requirements. In addition, a number of trend-setting functionalities specifically tailored to the needs of a grain terminal were incorporated.
Silo Wil AG’s customers can rent grain storage capacities. The basis for such rentals is formed by contracts with product specifications and tonnages. As a consequence, partial deliveries under such contracts are continuously stored or retrieved, with very frequent product movements taking place. The WinCoS.r2 “Contract-, Lot- and Layer-Management” modules enable optimal and user-controlled linking of the basic contract data with the daily product movements in the plant. This also prevents undesirable product cross contamination. Quantities, deliveries and inventory data can be retrieved by just pressing the button per customer or contract at any time.
Another goal was to enable grain deliveries beyond regular office hours without compromising convenience, data security or product safety. This goal was achieved with the so-called “Grain-O-Mat” module.
The “Grain-O-Mat” works like an automated banking teller, with grain being withdrawn instead of money. The truck driver signs in at the device with his registration license. The driver can then retrieve the pre-ordered, specified delivery and thereby automatically obtains the required grain quantity. Self withdrawn deliveries are recorded by the system.
The highly complex receiving, cleaning, storage, and turnover operations, which can be carried out simultaneously, require optimized route selection for job processing. WinCoS.Routing offers this possibility. Upon request, the system suggests optimized routes to the user, giving consideration to parameters such as short distances, machines and elements already occupied, and the necessity of a cleaning or weighing process. Proposed route patterns can be reused either unchanged or modified for next jobs. This provides optimal support to users in their daily planning tasks.
Rudolf Peter is a sales representative, Automation Grain Processing, for Buhler AG. He can be reached at firstname.lastname@example.org.