The new vacuum-tube lifter JUMBO Ex-Schutz from the vacuum-technology specialist J. Schmalz GmbH in 72293 Glatten has been accepted very well in the market and is already being used successfully in a wide range of applications.

This vacuum-tube lifter is made of stainless steel and equipped with a pneumatic vacuum generator (multi-stage ejector of the type SEM 300 Ex) and is the only device currently on the market which complies with the EU Directive 94/9/EG (ATEX), which came into force on 01.07.2003. The vacuum-tube lifters of the JUMBO series were modified with respect to the requirements of Group II (surface systems), which is divided into the so-called zones (0, 1, 2, 20, 21, 22) and device categories (1, 2, 3), such that they meet, without restrictions, the safety requirements of zones 1 and 2 ("Gas") and 21 und 22 ("Dust") with respect to the "avoidance of effective ignition sources in normal operation and in the case of common operating faults". Such considerations are relevant in industrial sectors such as the manufacture of chemicals, paints and pharmaceuticals, the treatment of wood, and large bakeries, since these industries often having working areas where dust accumulates and could result in a dust explosion.

In order to achieve the required explosion protection, the materials used for the vacuum-tube lifter JUMBO Ex-Schutz were selected specially for the task and were processed to provide a high degree of explosion protection. The devices contain no electrical components and are made primarily of stainless steel, in some cases with antistatic coatings. The mechanical parts and assemblies, and also the plastic and rubber parts, are all antistatic or conductive. The aluminium parts are suitably coated. This explosion-protected design improves the process safety for the handling of sacks in bulk-goods systems, for the movement of containers in the paint industry, for the handling of sheets of wood and for the handling of containers in the chemicals and munitions industries.

Practical solution

The company Weilburger Coatings GmbH in 35781 Weilburg were impressed by the approval for use in explosion-hazard areas and by the other advantages of handling with vacuum-tube lifters. Amongst other things, Weilburger Coatings manufactures industrial coating substances which they make from various raw materials in a mixing centre. The raw materials are delivered in sacks weighing 25 kg which, in the past, were transferred manually from the pallets to a mixer. This physically strenuous work quickly resulted in fatigue in the persons doing it, and there were also various health problems. For this reason, the company was looking for a suitable device to make the work easier and safer and finally found this at the vacuum specialist J. Schmalz GmbH. The vacuum-tube lifter JUMBO Ex-Schutz 65 was tested for suitability and proved to be ideal for the intended tasks. Made of stainless steel, and combined with a monorail overhead crane, also in stainless steel, this explosion-protected device now permits fast, precise and safe movement of the sacks from the pallets to the mixer.     

Universal use

As already mentioned, the sacks contain the raw materials for the manufacture of coating powders. The sacks may be made of paper or plastic, but this is no problem for the universal vacuum gripper. The worker lifts the sacks from a pallet with the vacuum-tube lifter and moves them to one of the two mixers. With the aid of the monorail overhead crane, both mixers can be served individually and effortlessly. In addition, the easy movement of the transport systems permits fast and precise positioning of the sacks above the inlets of the mixers. The vacuum-tube lifter has not only improved the system throughput. It has also contributed to more humane working conditions: the workers no longer complain of backaches and thus work more effectively. It is thus no wonder that the customer is very satisfied with the vacuum-tube lifter, particularly since it has being working without faults for some time and no-one would like to return to the old system of manual handling.