Expertise in Bulk Materials Handling

Bulk handling of materials is crucial for a range of industries. However, they all share similar engineering and technical aspects. Industries involved with extraction and mining as well as industries importing and processing raw materials have common needs. One of these requirements is the use of hydraulic, pneumatic and electrical systems to safely and efficiently drive and control the process of materials. High performance, low energy consumption, dynamics and outstanding control are just some of the properties a modern drive strategy must provide to meet increasingly high customer expectations.

Bosch Rexroth, with its extensive product portfolio covering a wide range of disciplines, has identified itself as "The Drive & Control Company". Over many years the team has developed expertise and experience in bulk materials handling and can provide a specialist knowledge and service to this sector.

Although of great importance, service needs to be about much more than having a strong product portfolio. Over a number of years, Rexroth has been able to also develop systems and engineering expertise in addition to systems build and testing facilities to satisfy all bulk materials handling application requirements. The application of products into customised, efficient and safe systems provides added value to customers and can only be offered thanks to the many years experience of extensive systems engineering and design. The acquisition of Hagglunds Drives earlier in 2011 has also added a complementary product range and systems expertise for direct hydraulic drive systems including a wide range of modular Drive Units designed to suit many applications in standard form.

Efficient and responsive aftersales services are vital to ensure that the systems are maintained once commissioned, allowing them to run smoothly and safely for a number of years. Bosch Rexroth's drive and control concept with power packs, cylinders, motors, gearboxes and electronics are tailored to the application at hand, but consist of components from its standard product range. This guarantees international availability of spare parts and local service knowledge. Additionally, Bosch Rexroth's regional Centres of Competence provide a network of system advisors who in partnership with Rexroth, provide comprehensive advisory service for specific customer issues.

The systems
Power units are designed to suit customer requirements which inevitably depend on the application and the environment concerned. In Bosch Rexroth the following examples are typical in bulk material handling applications:

• Belt Conveyors - There are at least three areas for hydraulic systems on belt conveyors. The first concerns the main drive where smooth variable speed enables a good starting and stopping characteristic. The drive should be able to start with a full load and if downhill, be able to take variable regenerative loads. A standard system with closed circuit hydraulic system will do this if powered from the grid. The belt tension system is also an important element to control the friction between belt and pulley to allow starting and running with variable loadings without slippage. Underground systems obviously have to conform to appropriate standards. For example with skid type explosion proof design to suit ATEX. Braking and auxiliary systems for clamping and reeling are also often required.

• Feeders - Often used for pulling raw material out of large storage hoppers and feeding out a controlled rate onto conveyors, railway wagons or sizers of various descriptions. Apron feeders are usually constructed from steel belts to provide the strength required for heavy duty work on large mine sites and quarries. Belt feeders are usually used for lighter materials and duties.

• Bucketwheel reclaimers, ship unloaders and tunnel boring machines - Large machines with multi axis controls which are needed for the linear movements and low speed drives of the main bucketwheel or bucket elevators. These are used in ports, large power stations or steelworks for handling stored coal, iron ore and other minerals.

• Train positioning and wagon unloading tipplers - It is important not to hold up locomotives and so these systems enable the automatic decoupling, positioning and unloading of wagons into underground hoppers. They minimise idle time while rapid loading of wagons is also enabled by multi clam shell door systems.

• Drums - There are many applications using large rotating drums. Inertia is the important aspect here and therefore the method used to stop and start the drives is equally critical. Some are heated to high temperatures such as cement kilns, furnaces or drying drums or apply pressure and steam such as waste autoclaves. Other types are just large such as digesters and diffusers. It is often required to drive with more than one drive making load sharing important. The mode of driving can be on the axis, using a pinion on a girth gear or by friction rollers on rings. Hydraulic drives provide a very good system for all types.

• Baling Presses - When plants produce large volumes of product one high cost is that of transport. One of the best ways to reduce these costs is to compress the materials into small compact bales so more material can be transported on a wagon. Some plants have many baling presses fed from a single ring main hydraulic system which provides a very economical way to operate many machines from one power source.

• Car shredding plants - Cars and other metal wastes end up at the fragmentation plant in bales or flattened by hydraulic presses . The material is fed onto a large hydraulically driven feeder which conveys the material to the hammermill. A roll feeder squashes the material and feeds it slowly into the mill where the rotor nibbles away the material into small pieces to enable sorting into differing material streams of steel, aluminium, glass, plastics, non ferrous etc for recycling.

The modern production environment demands reliability and flexibility from plant equipment, allowing it to cope with the wide range of variables which may occur. This is essential if high productivity is to be sustained and profit levels to be maximised. Rexroth puts you in touch with leading engineers in heavy systems engineering incorporating hydraulic drive systems and controls, servo drives and controls, pneumatics, linear and factory automation. The scope of Rexroth products for heavy engineering projects is unrivalled and thanks to its expertise in applications, provides a comprehensive service and unique solutions to all heavy industries.

Bosch Rexroth is one of the world's leading specialists in the field of drive and control technologies. Under the brand name of Rexroth the company supplies more than 500,000 customers with tailored solutions for driving, controlling and moving. As 'The Drive & Control Company', Bosch Rexroth develops, produces and sells components and systems in more than 80 countries in the technology fields Electric Drives and Controls, Industrial Hydraulics, Mobile Hydraulics , Linear Technology, Assembly Technology and Pneumatics.