Press Release



(Press Release, July 2009)

Drive Technology for the Fruit-Juice Production Industry


Air Motors for Agitators

Teaming with heath, they are colorful and varied: Fruit Juices are made from all types of fruits. The drinks provide countless vitamins and minerals, and are perfect for the health-conscious. Many scientific studies underline the connection between an ample and varied intake of fruit and vegetables, and the reduction of diet-related illnesses. The initiative “5 a day" has the goal of persuading people to eat five pieces of fruit or vegetables per day in order to meet all the body's needs. If you require a quick fix then the practical answer is a portion of fruit or vegetable juice.

In Germany, apple juice wins the top spot as the nation’s favorite soft drink, followed by orange, multi-vitamin and grape juice. Around 800,000 tons of fruit were processed by 411 juice producers in Germany that are registered with the German fruit juice industry's registered association. In 2007, approximately 7,000 workers processed fruit into 4.04 million liters of fruit juice drinks. There is also a great variety of fruit juice drinks on offer in supermarkets. Bottles and cartons with bright, eye-catching printed designs compete on the shelves. “Smoothies" are the newest fad from the United States - more pulp than juice - the perfect fruit snack. One popular children's drink packaged in an aluminum packet with an attached straw has been on the market for over 40 years.

Lots of people do not drink enough, especially children. Nutritional experts say adults need between 1.5 and 2 liter of fluid a day, while children over 10 need 1.5 liter per day and younger ones a full liter. Mineral water, unsweetened tea drinks, fruit squash, fruit juice and other fruit drinks are all tasty ways to fulfill your daily fluid intake requirements.

In one liter of apple juice, you get the equivalent of the benefit of three kilos of apples!

Before it gets to the glass, though, fruit juice has a long road to travel. Today, the manufacture of juice, fruit drinks and smoothies is mainly automated. Because hygiene standards are very important in the food industry. The production and packaging of fruit juice is controlled by computers to ensure high processing reliability. Systems that conform to food-industry standards are preferred when designing production machines. The motors that drive these systems must also meet the very highest standards. Air motors, in particular, must run oil-free, be temperature insensitive and suitable for use in clean rooms. They must also be resistant to solvents for cleaning and disinfection.

Only the so-called “direct-juice" is bottled directly into bottles and cartons. The usual practice is to remove most of the water after the pasteurization of fresh juice, so that the fruit concentrate can be stored and transported more easily. This fruit concentrate is the basis for pure juice, nectars or mixtures. Manufacturers then mix the concentrate with water and sugar according to their own secret recipe to create the actual drinks. This is done in large containers where the mixture is both stirred and heated to 80 degrees Celsius so that it will be sterile when it reaches the final packaging station.

The automatic agitators that are used to do this stirring need to be equipped with motors that are both heat resistant and resilient. In fact, air vane motors are well suited for use in a wide spectrum of food-industry applications. An Example: For the stirring and mixing of fruit juices, we offer a robust and reliable air-motor made from stainless steel with a power output of 300 watts and a nominal speed of 700 rpm. This motor drives the propeller or the dissolver disk of a magnetic agitator.

Air Motors are also well suited for the use in food processing applications due to their simple design, low weight, high torque range and explosion-proof performance. The air motor works on a simple principle. The air pressure, which is generated by a compressor moves the rotor, which is encased in an eccentric cylinder. Vanes, which are located in the rotor slots, are pressed outwards against the cylinder wall by the rising centrifugal force. Working chambers are formed for the compressed air. The expansion of compressed supply air changes into kinetic energy and rotational movement is generated.

DEPRAG SCHULZ GMBH & CO. KG, based in Amberg, Germany, has long been a renowned specialist in the field of air vane motors. Its ADVANCED LINE motor range is widely recommended for use in the food industry. The range includes a comprehensive selection of non-corrosive, sealed air- motors suitable for oil-free use. These high-quality stainless steel motors are well-suited for the food industry, but also find their use in the paper-, chemical-, pharmaceutical- and medical industries. Advanced Line air motors are small and therefore practical for use in both handheld machines and larger systems. The extensive power range stretches from 20 W to 1.2 kW, from low speed motors up to high revolution speeds of 24,000 rpm. The motors are certified for use in potentially explosive environments and come equipped with ATEX-certified integrated holding brakes.

There are many advantages in using air motors. The main benefit is the high performance density. Depending on the model, they only require one-fifth of the electric motor's net mass or one third of the overall size. This is important not only in handheld machines, but in robot systems or NC machines where the drive has to be indexed.

The performance of the air motor is almost constant even in high speed ranges. It can therefore be operated optimally within a wide field of changeable 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 and is not damaged by this in any way. When the load is reduced it restarts immediately and successively as many times as required.

Over the years, DEPRAG engineers have continued to update their air motor line to meet the needs of the company's customers. Per DEPRAG Product Manager Dagmar Dübbelde: “The Advanced Line motors of our product spectrum have been developed specifically to comply with the high hygiene standards of the food and medical industries. 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.

The air-motor is insensitive to heat buildup. Because of an air-motors principle of operation, it is perfectly suited for the use in critical environments. Through the decompression of the air, the air motor cools down and therefore overheating would be impossible. Thus, pressurized air in itself is an uncomplicated source of energy: there is no threat of danger associated with electrical connections of any kind.

The development and design of top-quality air motors is one of the main areas of expertise of DEPRAG SCHULZ GMBH & CO. KG. The Bavarian specialist for air motors, automation, screwdriving technology and air tools operates with around 600 employees in almost 50 countries. DEPRAG offers all-inclusive services; not only providing stainless steel motors for systems, but also developing tailor-made complete drive solutions for individual applications. Decades of experience enable the DEPRAG engineers to provide valuable support for their clients in the design and customization of motors.

Press Contact:

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

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