The company Adolf Zeller GmbH & Co. is investing in the future with the state-of-the-art technology and setting new standards for the KFW 40 and zero-energy home. To further improve the well-known and proven Zeller brick quality, the companies Adolf Zeller GmbH & Co. and Keller HCW jointly installed a new grinding plant. With this system, products from all three existing production lines can be handled in one grinding plant. The newly installed grinding plant is fed in conjunction with the pre-existing automatic storage feed system. As a result, it is possible to feed the products directly to the grinding plant or, if necessary, store them intermediately and feed them at a later date from storage to the grinding plant. The automatically operated crane system for the storage feeding takes up six packs stacked on pallets simultaneously and places them onto a conveyor of the new grinding plant. These are then automatically moved into the de-stacking position and prepared for de-stacking with a robot.
Feeding
Only one robot is used for de-stacking and feeding the bricks to the grinding plant as well as for setting the dispatch packs. This robot is equipped with a special gripper that can additionally undertake the handling of empty pallets from the de-stacking position into the loading position. Despite the output of more than 1 600 units/hour of size 12 DF, the robot works smoothly and handles the product gently.
The set-down product groups are separated into individual rows and fed to the grinding plant. When entering the grinding plant, the products are precisely aligned to the centre axis of the grinding plant so that they can be ground dimensionally exact and square. The transport of the products through the grinding plant is effected in one layer or, if required and depending on the size, the products can be stacked two high.
Grinding plant
Inside the grinding plant the products are ground in two grinding stages to the predetermined dimension set by a laser. The transport speed is continuously selectable from 3 up to 16 m/min and can therefore be adapted to the product characteristics. After the grinding process, the bricks are cleaned and fed to the stacking plant.
To keep the grinding noise as low as possible, the complete grinding plant is provided with a sound insulating cabinet, which can be optionally equipped with sliding or swing doors.
Stacking and further transport
For feeding the ground bricks to the stacking plant, lifting chains are used, which accelerate a brick group and deposit the bricks onto an angle table. Further transport is effected laterally in a turnover device. By means of this turnover device the bricks can be optionally turned onto the cutting surface.
In the area of the turnover device, inclined collecting plates are installed onto which the residual dust or even broken pieces can be discharged. For disposal of the dust, this area is also connected to the de-dusting plant and therefore the accumulated dust is also fed to the de-dusting plant.
The complete setting layers are prepared on a collecting table for take-up by the robot. For output reasons, the table is designed wide enough so that two product layers can be collected in parallel and taken up by the robot. The feeding of empty pallets is done by means of a robot. However, before they can be transferred, they are cleaned following the unloading process.
The stacked packs are fed to an existing crane system with a chain conveyor and by means of an existing packaging plant they are packed with stretch wrap film and taken to the unloading position via chain conveyors.
For the production of heat-insulating bricks, the holes of the precisely ground bricks are filled during another working step with an insulation made of rock wool. This process is also automated and intended for bricks with various wall thicknesses.
Control system
The complete machinery is controlled by the proven Simatic S7 control system. Mechanical intervention when changing sizes is not required. By pre-selecting the respective size at the control desk, the entire plant is set to the desired programme and the desired operational mode. The control system also allows for the manual operation of all plant functions.
Thanks to the investments made, as well as the improved production possibilities, Adolf Zeller GmbH & Co. is one of the most innovative brick manufacturers and sets new standards with the products it supplies on the market.
