Sales of solar systems are booming and the continuing increases in the prices of fossil fuels is filling the branch with optimism for the future. In addition, the state subsidies offered in many countries for the use of solar systems on houses and industrial buildings have led to increased demand, which means that the manufacturers of such systems are having to expand their production and distribution capacities.

One such company is General Solar Systems GmbH, which specialises in the supply of thermal solar systems for hot water and for supplementing heating systems. Since the beginning of 2006, the company belongs to the Austrian company General Solar Systems, Europe's leading supplier of solar solutions. The German subsidiary does not have production facilities, but acts as a logistics centre which supplies installation firms with collectors, storage tanks, installation materials and various accessories.

In the largest German logistics centre for solar technology in Ravensburg, the various components and systems for solar applications are stocked, commissioned, packed and finally dispatched to the customers. Particular attention has to be paid to the handling of the solar collectors, which are available in various sizes of up to 1200 x 1900 or  2100 mm and weigh between 38 and 45 kg. Up to 200 such collectors are handled each day, a task which previously required the combined efforts of up to seven strong men. However, since a typical order comprises two to four collectors, a storage tank and various installation materials and accessories, and since the number of orders has increased steadily, these men were no longer able to handle all the hard work involved. For this reason, the company management decided to invest in practical aids for handling the components.

Economical commissioning of
easily damaged solar collectors

Since the production facility in Austria had already introduced vacuum handling for the collectors and was very pleased with the results, it was only logical to rationalise the materials handling in the logistics centre in Ravensburg with the aid of vacuum handling systems from the vacuum specialist J. Schmalz GmbH, D-72293 Glatten.

After analysis of the requirements, a vacuum tube lifter JumboErgo 85 with pneumatic swivelling unit PSE was selected as the ideal solution and was accordingly purchased. The vacuum tube lifter JumboErgo with PSE, with its maximum load of 70 kg, offers sufficient reserves for the handling of collectors of all sizes safety and reliably. To ensure safe handling of the collectors, which are gripped by their smooth front surfaces, the lifter is equipped with a beam which carries four suction pads.

The pneumatic swivelling unit PSE permits the operator to swivel through 90° from the horizontal to the vertical position without the need for assistance by additional workers. The vacuum tube lifter is suspended from a slewing column crane with a jib length of 4500 mm and a slewing range of 270°, thus providing a large working area. The necessary vacuum is generated by a directly-driven blower of the type Schmalz Blower SB-L, which is installed in a silencer box to reduce its noise level to about 65 dB(A).

The commissioning procedure is now as follows: the collectors arrive from GreenOneTec in Austria and suppliers in other countries stacked on pallets, each pallet carrying about ten collectors. The pallets are first moved from the truck to the main stockroom and taken from there as they are needed for the orders (on average, about 1000 collectors per day). The 100 pallets with ten collectors each (= 1000 collectors) are placed in a transit rack, from which they are moved by a fork-lift truck to the commissioning area.

Here, several persons commission the components in accordance with the customer orders. The components for each order, including the storage tank but excluding the collectors, are placed on a pallet. The pallet is then moved to the loading and commissioning area for collectors.

Vacuum handling offers many benefits

The vacuum tube lifter JumboErgo is now used to lift the necessary collectors from the stacks on the storage pallets, swivel them by 90° to the vertical position and place them upright on the delivery pallet. The upright position has the advantage that it makes best use of the available space in the delivery truck and that the collectors can be better protected against damage by means of edge protectors and by wrapping the components on the pallet in shrink film. After it has been loaded and wrapped, each pallet is parked ready for collection by a truck.

Working with the vacuum tube lifter in the logistics centre of General Solar Systems in Ravensburg is now highly efficient. Today, a single person can handle at least three times the number of collectors than was previously possible with seven strong men. The centre operates in two shifts, which means that one commissioning station with a vacuum handling system is sufficient to handle even the enormous throughput. Last but not least, the safe, precise and reliable handling of the collectors also avoids damage to the collectors and thus the expensive handling of customer complaints, and this of course has a positive effect on the economics of the logistics centre.