Press Release



(Press Release, May 2009)

How does the flour get into the bag?


Stainless-steel air-motors are predestined for use in the food-industrys bulk processing

Germany is known worldwide for its wide-ranging selection of breads and pastries. This, in turn, poses a serious challenge to the country's over 700 mills, which supply Germany's baking industry with high-quality milled grains. to the Verband Deutscher Müller (Association of German Millers), more than 6,000 Germans now earn their daily bread milling grain. In Germany, the per-capita-consumption of milled grains is 67.1 kilograms per year, the milling industry generates revenues of about 2.1 billion Euros and processes a variety of ground products from 7.7 Billion tons of wheat and rye.

To be a miller is an interesting subject. Instead of hauling around sacks, sweeping floors and manually changing mill wheels, today's mills employ a wide range of cutting-edge technologies, including high-tech digital milling programs, computer controlled systems and quality monitoring in the milling laboratory. Automation is also on the rise, especially in the larger mills. Machine builders are constantly being pushed to the limit as they develop newer and better ways of both milling and material handling. Individual components or complete assembly stations are in demand and the competition is fierce.

No matter what the application, explosion prevention is a critical issue because of the amount of dust created in the typical mill and hygienic standards - as in every food industry - are also a major concern. Therefore, safety and traceability are important factors for the milling industry. The drives that are used for milling, material handling and bulk processing have to meet an especially high set of standards. Hygienic, easy to clean, suitable for use in the food-industry and if possible usable in an explosion-hazardous environment, are some of the items on the wish list for suppliers of motors to be used in automation and assembly systems.

Air-vane motors made from high quality stainless steel have proved ideal for such applications. DEPRAG SCHULZ GMBH u. CO. KG is an internationally recognized manufacturer of air-motors, automation, screw-driving technology and power tools. DEPRAG engineers have perfected their air-motors through decades of research. High-quality stainless-steel motors of the ADVANCED LINE are now at the disposal of machine builders. These motors offer many advantages.

In fact, air-vane motors are well suited to a wide variety of applications, thanks to their versatile design options, simple design, light performance weight, high speeds and explosion resistance. Air vane motors operate according to one basic principle. Compressed air, generated by a compressor, induces the motor to rotate. A vane-motor operates as follows: Compressed air is used to set a rotor in motion inside an eccentric cylinder. Vanes, which are located in the rotor slots, are pressed outwards against the cylinder wall by the rising centrifugal force. This leads to the formation of chambers for the expanding air pressure. As the compressed air expands, the pressure energy subsequently transforms into kinetic energy, thereby producing the rotary motion.

Hygiene is a must in operations where there is any milling of flour for breads. Due to the robust and fully-sealed design in stainless-steel material, the vane-motors of the DEPRAG ADVANCED LINE are perfectly suited for the use in the food industry. The smooth surfaces are easy to clean and the drive is also resistant to chemical cleaning agents. The motors are completely sealed, so there is no chance of leakage or penetration of dirt. Motor spindles are also resistant to chemical cleaning agents and come equipped with a durable radial shaft seal-ring.

Because of an air-motors principle of operation, it is perfectly suited for the use in critical environments. As the decompressing air makes its way through the motor it loses temperature, keeping the motor cool, even under load and over-heating is practically impossible. The motors internal overpressure prevents the intrusion of dust and dirt.

The stainless steel air vane motors of the Advanced Line are well suited to oil-free operation, an essential feature with respect to clean rooms and throughout the food industry. Different vane types are available for use in various specific applications. The motors are available in standard capacities ranging from 20 W to 1.2 kW, and in a broad speed range from 16 up to 24,000 rpm.

Explosion safety is a serious issue in the milling industry. The fine dust found in grain produce, storage and packaging is highly explosive. Compressed air represents a largely trouble-free energy source. Danger is reduced because there are no electrical lines or other electrical sources.

DEPRAG no offers an ATEX line of certified brake motors for use in vat draining applications in the chemical industry. Developed in conjunction with bulk-good experts at Beer-Fördertechnik, Bad König, Germany, these air motors are now an integral part of DEPRAG's standard product line.. The use of such a total-package saves the machine builder additional design- and production costs. The brake is fully integrated into the drive and a compact planetary gear, which corresponds to the torque/speed requirement of the customer, is included as well.

The integrated brake, which functions as a holding brake, consists of three brake-disks, a spring and a piston. The Brake is controlled by a separate pressure line. When the air supply in the control line is over three bar and the spring load is less than the compression force, the stress is taken off the disks and the motor can rotate freely. When the pressure in the control line falls below three bar and the spring load is greater than the compression force. The Result: The brake disks are forced against each other and the motor is blocked.

An additional safety valve is mounted onto the brake for applications in potentially explosive environments; the air supply is shut down as soon as the pressure falls below five bar. This ensures that the air pressure in the control line is equal to zero during the braking process. "With this new complete system we have been able to launch an attractive system onto the market which fully complies with the ATEX standards (EX II 2GDc IIC T5 (95°)). “With this new complete system we have been able to launch an attractive system onto the market which fully complies with the ATEX standards" says Product Manager Dagmar Dübbelde.

DEPRAG SCHULZ GMBH & CO. KG offers a full service package for almost every industrial sector and is represented by 600 employees in 50 countries. One of their main areas of expertise is the development and manufacture of air motors. The DEPRAG engineers have had decades of experience in the planning and design of air motors according to customer specifications. Individual customer requests often lead to innovative developments which then become great value additions to the standard program.

Press Contact:

Dagmar Dübbelde
Carl-Schulz-Platz 1
D-92224 Amberg
Tel: 09621 371-343
Fax: 09621 371-199

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