The performance of the facility has been significantly increased by the installation of a Demag warehouse management system and a Demag process crane that has a load capacity of nine tonnes.
“We modernised the store operated in Lixhe by CBR with a strong solution based on rugged crane systems and smart control modules,” Lutz Dowy, the vice president for sales and product management at Terex Material Handling, explained. “The result ensures a continuous material flow thanks to consistently high handling rates.”
HeidelbergCement addressed three clear goals with the automation of the raw material store at its Belgian plant in Lixhe: increased productivity, sustainable improvement in process reliability and a higher level of occupational health and safety.
To meet these requirements, a fully automated crane was installed and a warehouse management system was implemented in the existing store. For the supply of the materials handling equipment and the software control system, the cement manufacturer decided in favour of a complete Demag system, which was used to thoroughly modernise the store.
Largest cement works
The Lixhe plant is one of the oldest locations operated by the cement manufacturer CBR, a subsidiary of the HeidelbergCement Group. With an annual capacity of some 1.4 million tonnes of clinker and 1.5 million tonnes of cement, the plant in southeast Belgium is the largest cement works in the Benelux countries.
Besides the calcareous sand that is quarried locally, three grades of coal as well as ferric oxide are kept in the raw material store at the plant. The storage area measures 86m x 24m in size and has five compartments that are divided into eight storage zones. Since a bridge crane serves the store, the owner benefits from full utilisation of the available space, as the crane can reach virtually any point in the store. A manually operated nine-tonne overhead travelling crane previously performed this work.
“The old crane installation had to be replaced because the electric equipment no longer met current standards and the structural design of the crane had to be revised,” Bertouil Hugues, a maintenance specialist at the Lixhe plant, explained.
“The crane also needed to be used in continuous 24/7 operation. This was no longer economically feasible with a manually controlled crane.”
Fill level scans
An automated Demag double-girder overhead travelling crane that is equipped with a 3.2m3 powered clamshell grab is now used for handling the raw materials. Like its predecessor, the process crane has a span of 24m and a load capacity of nine tonnes. Rugged and reliable crane components provide for continuous operation in the harsh environment. Efficient operation of the crane is also supported by high speeds (long travel motions at 100m per minute, load-dependent lifting motions up to 90m per minute) and integrated load-sway damping. The crane installation is primarily used for clearing the tipping pit and for filling the chutes with the required blend of materials, which is ensured by crane weighing devices.
The blend and order in which the material is added is precisely defined by the Demag warehouse management system, which controls the feed schedule to the kilns and facilitates transparent inventory management. Scanner systems were installed on the crane installation to measure the height of the aggregates. The scanners fitted below the crane bridge continuously track the height contours of the stored bulk material each time the crane travels over it. The software in the crane control centre uses the information to determine a constantly updated height profile and visualises the fill levels in all storage areas, including the minimum and maximum values. In addition, the control centre shows the current status of the crane with all relevant status messages. Customer-specific storage strategies can be added via the user-friendly interface at any time.
Some six months after the installation entered service, Hugues made an initial assessment. “The automation of the processes has enabled us to boost the efficiency of our raw material store,” he said. “Besides the higher handling rates provided by the crane system, its continuous operation without the need for any breaks has also contributed to the result. In addition, we have considerably enhanced the stability of our processes and further improved the safety of the working environment for our employees.”
Source: Terex Material Handling/Demag Cranes & Components