Press Release



(Press Release, September 2008)

Drive Solution for the Paper Industry


Acid- and heat-insensitive stainless-steel motors for difficult requirements

Germany's paper industry is No. 1 in Europe. With a sales of approximately 14.9 billion euro Germany places 4th worldwide behind the USA, China and Japan. A total of 3000 different kinds of paper are manufactured at around 180 production locations. 44,000 employees work to produce around 23.2 million tons of paper per year. The innovative paper manufacturing machinery ensures that the ravenous paper appetite of industrial nations is continuously satisfied.

How did paper originate? since 105 AD - the date when the process of paper manufacture was first recorded - the procedure has changed very little. Fibers are moistened in water and then scooped up with a sieve. This paper web is later pressed and dried. Today gigantic paper machines are used in the various processing steps to turn the pulp into paper. This is an enormous challenge for machine constructors as individual components have to be able to withstand extreme conditions. DEPRAG SCHULZ GMBH & CO. KG in Amberg, Germany manufactures air vane motors made from stainless steel, which are proven to be the optimal drive solution for numerous areas of application.

The material processing of paper machines for example: pulp and wood pulp as well as waste paper fibers are mixed in a certain proportion depending on the type of paper and then diluted in water. Chemical bulking agent and material aids are also added. This aggressive liquid must be "stirred" again and again. The motor used for this job has to be extremely robust: an air motor! The DEPRAG air vane motors made from stainless steel are ideal because they are designed for use in extreme conditions. They are water vapor resistant, insensitive to acids and heat and are high performance, durable machines.

DEPRAG SCHULZ GMBH & CO. KG in Amberg, Germany is a renowned specialist for high quality air motors. Their air vane motors from the motor series 67- are designed with stainless steel housing as standard. All motors for application in the paper industry are totally sealed and exhaust air cannot escape nor can dirt infiltrate from the motor surroundings. The drive spindle is from made from high quality non-corrosive stainless steel and is insensitive to aggressive chemicals. In particular it has a highly resistant radial shaft seal. These stainless steel motors are ideal drives for wet rooms and bear-up well against the acidic materials used in fiber preparation at paper factories.

Air motors can be applied in a wide spectrum of fields due to their diverse design versions, simple design, light performance weight, high speed ranges and explosion proof. The air motor works on a simple principle. The air created by the compressor causes the motor shaft to rotate.

The 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 creates working chambers for the expanding air. The expansion of compressed supply air changes into kinetic energy and rotational movement is generated.

There are many advantages to using air motors as a drive. The main benefit is the high performance density. Depending on design they only need a fifth of the weight of a standard electric motor or a third of the size.

The generated performance is almost constant for this motor type over wide speed ranges It can be operated over a wide range of varying loads. The motor performance can be adapted by altering the operational pressure and the speed can be smoothly controlled by throttling the air quantity. The air motor can be loaded until standstill without problems or any kind of damage. When the load is reduced it restarts immediately and successively as many times as required even at high duty cycles.

Another advantages of this drive medium: The air decompression cools down the friction heat created by the air motor; it cools the motor under load and overheating is almost impossible. Additionally the inner excess pressure prevents the intrusion of dust and dirt.

Oil free operation of the air motor in dry run, as required by the food industry, is also possible with an only low loss of performance.

All DEPRAG stainless steel motors are fitted with planetary gears made from stainless-steel as standard A 1.2 kW motor with a speed of 4500 U/min can also be delivered with various planetary gear speeds of 1250 U/min, 550 U/min, 350 U/min, 160 U/min or 100 U/min as standard.

Air motors are far superior to standard electric motors in their compactness and performance. A 1.2 kW strength vane motor with integrated planetary gear with nominal torque of 350 U/min is only 268 millimeters long and 82 millimeters in diameter.

Using an air motor also eliminates the possibility of a short circuit, this is a further advantage over the electric drive. DEPRAG SCHULZ GMBH & CO. KG even offers an ATEX certified stainless steel motor with integrated holding brake as standard.

Whether used for material preparation in paper manufacture, the transporting unit of a paper machine or for cutting the base paper into strips, the stainless steel air vane motor is an all-purpose piece of equipment", says Product Manager Dagmar Dübbelde.

DEPRAG offers a large selection of stainless steel motors especially made for the paper industry. These motors are attractive because of their robustness and high performance.

DEPRAG SCHULZ GMBH & CO. KG is an international leading supplier of air motors, air tools, screwdriving technology and automation. The company is represented in 40 countries with over 600 employees. One of their main areas of expertise is the manufacture and development of air motors. The DEPRAG engineers have decades of experience in working hand in hand with their customers in the development and purpose-driven customization of their motors for individual applications. 85% of all projects are customer specific applications. Even for low volume requirements, DEPRAG offers individually customized standard motors, special motors or fully automatic production systems.

Press Contact:

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

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