At bauma, BHS-Sonthofen demonstrates the rotor
centrifugal crushers of the RSMX series for processing hard and medium-hard rock to produce aggregate chippings and high-quality aggregates. The “rock-on-rock” principle and the patented rotor with just two centrifugal chambers offer considerable advantages over multi-chamber rotors in everyday practice.
The requirements on the building materials concrete and asphalt – and thus on the gravel, chippings and sand used for their production – have continuously risen in recent years. Since demand for high-grade crushed sand and high-quality aggregates is also constantly rising, gravel and aggregate plants have to expand and equip their machine pools in order to meet the European standards and directives that require increased use of high-quality aggregates. BHS offers machines in four different sizes for throughput rates of up to 400 t/h. Crushing with BHS impact crushers with vertical shafts and twin-chamber rotors is a popular choice in many plants for the production of high-quality aggregates.
BHS rotor centrifugal crushers adopt the impact crushing principle: the material is fed vertically from above onto the high-speed rotor, which is mounted on a shaft with vertical bearings. In both chambers of the rotor, the input material is rapidly accelerated outwards due to the high circumferential speed, routed out via a naturally forming material bed and hurled at high speed against a fixed annular wall, generally consisting of an anvil ring made of heavy-duty casting or an autogenous material bed.
The rotors patented by BHS with just two centrifugal chambers offer considerable advantages over three-chamber and multi-chamber rotors:
• maximum input grain sizes of up to about 80 mm for hard rock and up to 150 mm for soft rock
• optimal material flow in the rotor, free from clogging
• 15 to 20 percent greater throughput rate with the same power consumption
• wear-related costs reduced by up to 25 percent
• exhaust air quantity reduced by more than 10 percent
Choice of rock shelf or anvil ring
The rotor centrifugal crushers from BHS can optionally be operated with an anvil ring made of heavy-duty casting or with a rock shelf, and can thus be variably adapted to a wide range of different requirements.
If the anvil ring is used, the input material is crushed intensively by the hard impact of the rock against the impact wall, thereby developing the crushed face count of the chippings. Previously damaged rock and friable components are destroyed, significantly improving the test results of the final products. The stepped shape of the anvil ring causes the crushed material to be removed immediately from the crushing chamber without further abrasion.
If the rotor centrifugal crusher is operated with a rock shelf, it is also suitable for highly abrasive input materials, such as quartz, as the “rock-on-rock” principle means that only very few machine components are subjected to wear.
Another advantage is that, unlike in other crushing systems, the condition of the wearing parts has no effect on the grading curve: it is only the speed of the rotor that determines the crushing performance.
Depending on the application specified by the customer and the properties of the rock, operation of the rotor centrifugal crusher can be varied:
• with anvil ring:
– as crusher and cubicator for the production of aggregate chippings and high-quality aggregates from soft and medium-hard rock
– for production of crushed sand
• with rock shelf:
– as crusher and cubicator for the production of aggregate chippings and high-quality aggregates from hard rock
• with rock shelf or anvil ring (depending on the application):
– for selective crushing of friable rock while maintaining the hard core of the material
– for disaggregation of conglomerates
Every kind of rock has different characteristics; for this reason, BHS conducts tests at its in-house technical center on request. These tests are carried out using original industrial scale machines to ensure optimal and realistic crushing results. These tests give the customer the certainty that his outlay is well invested and that the new plant is future-proof.
Hall B2; Stand 325/420