Handling large quantities is important for the liquid gas supplier Westfalen Group and its subsidiary Caratgas. With the modular system from conveyor technology manufacturer HaRo Anlagen- und Fördertechnik, the conveyor system installed at Caratgas in Krefeld for filling gas cylinders was able to grow in line with the increased capacity utilization within a short space of time. Combined with Industry 4.0 technologies such as digitalization, automation and AI, this results in new levels of productivity and competitive advantages in all aspects of material flow. This year's LogiMat will therefore also focus on intelligent and autonomous systems that create new perspectives for the future.

The Westfalen Group is active in the fields of technical gases, cooling and heating, filling stations and mobility as well as respiratory home therapy. With its products and services, it is increasingly offering solutions that help customers to become more sustainable. The family-owned company has numerous subsidiaries and associated companies at over 20 production sites. In Krefeld, Caratgas focuses primarily on the storage, filling and handling of liquid gas. The company approached the HaRo Group back in 2020 with a request to install two conveyor systems. The first was a powered conveyor system for empty and full steel pallets with an automatic push-out system for depalletizing empty gas cylinders and an automatic push-in system for palletizing filled gas cylinders. The second conveyor system, which is also powered, is used to transport empty and full steel pallets with an automatic push-out system, but only for empty gas cylinders that are subject to TÜV inspection. HaRo designed an intelligent concept for both requirements, consisting of the two main components of driven roller conveyors and chain conveyors, which depalletize and palletize the gas cylinders fully automatically before and after filling.

The details of the first system: the single or double steel pallets are initially loaded manually using a forklift truck. Once the employee has acknowledged the loading of the goods using a switch, the single pallet moves directly to the push-out unit using the powered roller conveyors, while the doubled pallet is first transported to the de-doubling unit after an automatic height check. "A vertical lifting unit equipped with forklift tines then separates the pallets and moves the lower steel pallet directly to the push-out unit," explains HaRo design manager Markus Löseke. Meanwhile, the upper pallet is lifted and, after the lower pallet has been removed, is lowered and also transported towards the push-out unit for depalletizing the gas cylinders. Once at the push-out unit, the transport securing device of the steel pallets is first lifted upwards, then the cylinders are automatically pushed off the steel pallet onto the chain transport line and transported to the filling system. The empty pallet is moved to the next free roller conveyor positions. To palletize the filled gas cylinders, the empty steel pallets are first positioned and secured on the full cylinder push-in unit using a stopper-pusher combination. The transport lock is then lifted up again so that the full cylinders are pushed into the pallet by the chain conveyor. After the palletizing process, the safety device is lowered again and the filled pallets are transported via the roller conveyors to storage.

To separate and palletize the TÜV-compliant propane gas cylinders, Caratgas installed a second conveyor system that works in a similar way to the first system: "At this system, the empty steel pallets are first loaded using a forklift truck and transported along the roller conveyors to the position of the TÜV-compliant empty cylinder insertion unit," says HaRo's design department. Once the safety device on the pallet has opened automatically, the empty bottles are pushed into the pallet by the chain conveyor. After the palletizing process, the safety device lowers and the steel pallet filled with bottles is conveyed to the removal station via the roller conveyors.

Creating new buffer options

With increasing capacity utilization, Caratgas turned to HaRo again two years after the installation of the conveyor systems with the aim of increasing the buffer options at the systems and decoupling the dependency on the manual forklift for loading and unloading. "We were able to meet these requirements by implementing additional chain conveyors and thus buffer spaces at the loading and unloading points of the system. The depalletizing and palletizing of the gas cylinders runs completely automatically," says Markus Löseke. "The requirements in today's industrial companies are changing rapidly, so it is all the more important to be able to adapt the internal material flow flexibly and easily to the changes," says HaRo Managing Director Christoph Hackländer. "That's why we always offer our customers the option of expanding existing conveyor systems with the help of our modular system - without the need for major interventions in ongoing production."

At LogiMat, HaRo presented an automated material flow consisting of two vertical conveyors with a height of around 8 m in combination with driven roller conveyors for the automated transportation of pallets.