Good as new - it’s retrofit

Since 1995, an automated storage tower manufactured by Kasto in Achern, southern Germany, has been installed at stockholder Heine + Beisswenger, underpinning fast, punctual delivery of an extensive range of steels to customers.

The Kasto Unitop automatic cassette system for warehousing holds an extensive variety of materials. Measuring 68 metres long by 13 metres wide, the facility has space for 1,300 cassettes, each of which can hold four tonnes of material up to seven metres long. 

A feature of the system is the storage and retrieval machine (SRM), located at the top of the storage block. It automatically removes a cassette containing the required material and transfers it to a carriage, which then makes the stock available at ground level at one of two storage and retrieval stations. Each has four locations, so the operator can store and retrieve several cassettes at the same time.

The system was showing signs of age, however. The control and automation technology was no longer up-to-date and the drives and positioning mechanisms of the SRM were unreliable. Breakdowns were becoming more frequent and procuring spare parts was increasingly difficult. In terms of throughput, the storage facility was struggling to cope due to the increasing number of orders being received. 

Torsten Meincke, plant manager at the Langenzenn centre says: “Mechanically, the system was still performing well. It is also ideally integrated into our processes and our employees are familiar with it, so we decided not to replace the system completely, but to modernise it with a full retrofit by the OEM.”

Kasto retrofit project manager Gerd Jakob adds: “In many cases, modernisation is much more economical than a new purchase. After all, large parts of our storage systems such as the steel construction are almost indestructible, so these components can continue to be used.”

During the retrofit at Heine + Beisswenger, Kasto replaced the existing S5 system control with a modern Siemens Simatic S7 400 PLC and updated the drive controllers as well as the SRM's positioning sensors and Profinet connection. The hoisting gear was given an efficient, three-phase drive and the power supply to the SRM and carriage was renewed to improve reliability.

Another modernisation task was the replacement of the carriage that receives the cassettes and delivers them to the storage and retrieval stations at the front of the Unitop. The carriage now has two roller conveyors instead of one to allow simultaneous handling of two cassettes. Additionally, the longitudinal travel speed of the new carriage is twice as fast at 120 metres per minute, increasing efficiency further. According to Meincke, 35 seconds is saved per storage and retrieval cycle.

The control panels serving the two storage and retrieval stations were renewed and Kasto also replaced the old hard-wired emergency operation of the SRM with a modern radio remote control. Meinke adds: “This makes maintenance work and eliminating malfunctions much easier because a technician no longer has to stay next to the SRM to operate it.”

The storage facility is now controlled and managed by KASTOlogic warehouse management software, which has a graphical user interface that makes operation simple and intuitive. It is connected to the SAP ERP system in used at Heine + Beisswenger. 

Meinke explains: “This gives us a uniform process from ordering through to delivery to the customer and also helps us to ensure a high level of inventory transparency.”

The conversion was completed in just two weeks, with Kasto engineers even working in the facility at weekends and over the Easter holiday to minimise disruption to the stockholder's day-to-day business. The operators were given in-depth training to familiarise them with the new system. Since then, the warehouse has been operating reliably at its increased efficiency level and Kasto is constantly available for troubleshooting and online remote maintenance via its service hotline.

For more information, visit www.kasto.com