Dunkermotoren drive solutions in intelligent wood pellet extraction system from Schellinger

The use of heating systems with renewable energies is becoming increasingly important, and not only for new buildings. Existing properties are also being converted step by step to green, efficient heat energy - the keyword being energy-efficient refurbishment. Especially for existing properties, the change is often difficult since a new heating system usually requires structural changes. In most cases, these are expensive and space-consuming. For pellet heating systems, however, there is an attractive solution that is neither expensive nor requires a special infrastructure for storage.

The company Schellinger KG from Weingarten enables space-saving pellet storage systems that make efficient use of existing space and can even increase storage capacity by up to 50% with the same space requirements.

Thus, multi-family houses, hotels or commercial enterprises can heat particularly cost-saving. This is made possible by the Pellet Maulwurf E3®, which was specially developed for large pellet stores. Thanks to robust and safe drive solutions from Dunkermotoren, a brand of AMETEK Advanced Motion Solutions, it regulates pellet extraction and empties each store reliably and completely, without any structural changes.

All good things come from above

Schellinger KG is a true pioneer in wood pellet production. At its two production sites in Buchenbach in the Black Forest and Krauchenwies in the district of Sigmaringen, the company produces around 120,000 tons of combustible Sonnen-Pellets®, which are made from 100% regional and renewable raw materials. Since 1998, the company has also been active in the field of storage technology for wood pellets and in 2004 it revolutionized the previous pellet storage with the introduction of its Sonnen-Pellet Maulwurf® extraction system. The special feature of the system is the extraction of the pellets "from above". The Pellet Maulwurf® works its way from top to bottom in the storage room. With the aid of three drive rollers arranged in a star shape, it moves over the press grain and gently meters it in front of the suction nozzle. This allows the pellet supply to be extracted in a controlled manner. Thanks to sensor-based, intelligent control, the system manages to completely empty the store independent of the room geometry. Whether round, angular or asymmetrical - with the aid of the mole technology from Schellinger, existing rooms can be used one-to-one for pellet storage. Compared to previously common funnel-shaped storage chambers, which must be planned already during the construction of the building and make subsequent retrofitting almost impossible, it can be achieved a space gain of up to 50% thanks to the Pellet Maulwurf E3®. Thus, larger quantities can be ordered and, if necessary, quantity discounts can be realized. In addition, the number of delivery processes is reduced and thus also the effort required to manage the storage. This in turn has a positive effect on the costs for the operator.

With the right drive through the winter

The three drive rollers arranged in a star shape drive the mole and meter the wood pellets in front of the suction nozzle. The rotation of the rollers and thus the movement of the mole is made possible by one brushless DC motor of the series BG 32 series from Dunkermotoren for each roller. Unlike the traditional brushed technology, a brushless motor does not produce sparks, which ensures compliance with all safety regulations in the fire-hazard application area. The attached planetary gearbox with specially welded output shafts also allows the drives to easily achieve high torques. These are needed to move the 15 kg unit safely and permanently, even on uneven terrain. Integrated electronics give the drive solution its intelligence and also serve as an interface to the higher-level control system. This ensures that all areas of the warehouse are reached and completely emptied. In all drive solutions from Dunkermotoren, the electronics are completely integrated into the motor housing as a standard and are thus optimally protected from dirt and dust.

Thanks to intelligent drive solutions from Dunkermotoren, the extraction system Maulwurf® from Schellinger KG provides a space-saving and economical solution for wood pellet storage. This makes the use of renewable energy even easier and is also available to businesses, apartment buildings, hotels, and local heating network operators with existing premises in an uncomplicated way.

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The dustier and drier the air gets, the faster the solar panels will get dirty. As photovoltaic systems’ operator you should not rely on the natural cleaning power of rain. Rather, after dusty periods, it is time to wash the panels in order to maintain the yield capacity of the plant. A solution is to climb on the roof by yourself to clean them with a washing brush on a telescopic pole. But for security reasons mainly and time saving, you’d better not do that.
And here we are: SolarCleano cleaning robot is the solution to do it in a safe and efficient way. The synergy of theory and practical experiences of the manufacturer from Luxemburg, enables the SolarCleano to clean all types of installations until 25° slope. The cleaning robot was equipped with a total of four Dunkermotoren drives, consisting of the BG 65S with PLG 63 LL gears each and the travel drives additionally with E90R brakes, which ensure that both the robot moves, and the brushes rotate.
Dunkermotoren motors were selected for their robust design and compactness of the motor unit. These features, together with the BG 65S's integrated controller, enabled SolarCleano to develop a compact cleaning robot that is as economical as possible and requires only one operator. This was also possible thanks to the support of our long-standing distributor for the Benelux, the Dutch company ERIKS BV, who did the tuning, developed a very compact control box and optimized the cabling for robustness and modularity.
The SolarCleano washing robot can run at speeds of up to 40 m/ min. The maximum driving speed can be continuously preselected with a rotary potentiometer on the remote control. Thanks to the joystick it is possible to drive forwards and backwards and steer to the right and left, while the other hand is free to limit the maximum driving speed at the potentiometer, to switch the water supply on and off, to reverse the burrs or even to arrange the water hose.
The two brushes are 1.20 m wide in the standard version, and other lengths are available on request. They fit 1 m wide standard solar panels; the overlap beyond the module is intended to ensure that the bristles double-clean the lower edge of the panel in just one passage. In total, experience shows the robot cleans around 1000 m²/h.
Each robot is equipped with two brushes, which are made of two types of bristles. The soft bristles wipe away pollen, sand and pollution, the harder ones are made to clean persisting dirt. SolarCleano offers four different types of bristle mixes based on dirt intensity. Also, the brush height is manually adjustable.
The robot cleans on standard water tap pressured water (2 bars). There are of course options to raise that pressure using an additional pump, especially if the roof is located high above the water source.
Two Dunkermotoren BG 65S with integrated speed controller rotate the front and rear brushes. The rotation direction of the brushes can be changed independently from the remote control. In order to achieve a good cleaning result, it should always rotate in the opposite direction to the driving direction. So, it throws the dirt dissolved with water and brush power forward, until it finally flows off with the water over the edge of the module.
The two others BG 65S drive the crawler tracks. These can also run forwards and backwards separately, so that the cleaning robot can turn on the spot. However, thanks to a “reverse” button on the remote control and brushes at both ends of the robot, a U-turn is never necessary.
A lithium ion battery supplies the motors with power. Two batteries are included in the supply, and they should be enough for an eight-hour working day.
SolarCleano is large, since it includes 1.2 m wide brushes and battery. Manual transport by one person is therefore not possible. For this reason, the manufacturers have devised a quick-release coupling system for attaching and removing the brushes and the battery, as well as for separating the power cable and water connection, in order to dismantle the cleaning robot into four parts. Once this is done, each part can be transported by only one person. The assembly and disassembly of the robot takes about five minutes and is tool-free.
With the SolarCleano, Dunkermotoren is now represented in another robot application and shows that brushless motors with integrated electronics are very well suited for these applications. Further applications for BG motors are particularly evident in the field of industrial automation for AGVs and shuttles.