Leuze sensor technology is used at multiple points to enable the processes to function safely and efficiently. By the time an apple reaches the supermarket and the consumer, it has already been through many different processes: It has been picked, checked, stored, sorted, and packaged. Few companies are as familiar with these processes as BayWa Obst GmbH & Co. KG. The company’s main location for the sorting and packaging of pome fruit is located in Kressbronn am Bodensee
Safety matters at the transfer station
Once a ten-lane sorting unit has automatically sorted the fruit, the apples end up in one of 50 water-filled channels, which is assigned to the respective sorting criteria. Then, the apple continues on its way to the packaging stage via one of 34 transfer stations. At the stations, the know-how of Leuze came into play: To prevent people from getting injured by an autonomous bin stacker – a rail-bound automatic vehicle –, a gapless safety device was requested. The experts from Leuze developed a safety concept for this application that enables bins to be transferred through a vertical protective field and can differentiate between people and forklift trucks. Thanks to the scalable safety concept, the project could be implemented with efficient use of resources and just a few safety components. This is because just one RSL 400 safety laser scanner from Leuze was installed for every two transfer stations. Thanks to its operating range of up to 8.25 meters and the parallel operation of different protective fields, the RSL 400 can monitor both transfer stations simultaneously. In addition, an ultrasonic sensor and a radar sensor are mounted on each station.
Interruption-free working
The (safety) technology is installed above the transfer stations to allow the use of the space underneath without barriers. A programmable safety control with the safety program developed by Leuze controls how the components interact. The laser scanner generates an adjustable protective field in front of two transfer stations. The ultrasonic and radar sensors detect when a forklift truck drives forwards into one of the stations. Only under these circumstances does a defined area in the protective field of the laser scanner open for the forklift truck. It can then collect boxes from this station. At the same time, the bin stacker can continue working in the background even while the bins are being taken away. All the other stations remain safeguarded by their own laser scanner protective fields, which are still active. If someone enters the danger zone, the system stops the bin stacker, and a warning signal sounds.
Dynamic material flow control
At the packaging stage too, sensors from Leuze monitor everything closely: PRK retro-reflective photoelectric sensors installed on the conveyor sections detect the transported produce, such as cardboard trays, each holding six apples. These sensors make it possible to optimally control the conveyor speed. The final selling units made up of small packages and outer packaging are loaded onto pallets and transported to the shipping area. To ensure that this process is also free from danger, MLD 500 multiple light beam safety devices from Leuze safeguard the transfer station against people accessing the area when this is not wanted.
