CRUSHING
A thyssenkrupp ERC 25-25 test plant at a hard rock quarry in Germany.
AN ECCENTRIC SOLUTION TO THE PRIMARY CRUSHING CONCEPT Designed initially as a smaller option for miners in underground primary crushing operations, the eccentric roll crusher can be adapted to the quarrying application as a workable primary crusher in mobile operations above ground.
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ompact but powerful, ultra-productive with excellent crushing performance, highly energy efficient and well balanced.” These are attributes featured in promotional literature describing the new eccentric roll crusher (ERC) from thyssenkrupp Industrial Solutions. The supplier says the ERC redefines the concept of primary crushing hard rock. As such, it is suited not only for use in underground operations but also in open pit mines and quarries, where its qualities are particularly useful in semi- or fully mobile operations. For decades, gyratory and jaw crushers have proved their worth in crushing hard rock. However, their application is limited by their high headroom, requiring capital-intensive construction of large-scale, costly caverns when used in underground operations. Moreover, in open pit operations they are only partially suitable for mobile use because of design-related residual imbalance-induced forces. Although low-headroom crushers such as double roll crushers and sizers have become established as primary crushers in the industry, design constraints mean they
are not considered capable of efficiently and economically processing hard rock. The new ERC, with its patented design of pre-screening and crushing features, combines a compact design and the ability to crush hard rock with high throughputs in an energy-efficient manner.
OPERATIONAL BENEFITS The ERC offers significant operational benefits. Its installation height is between 20 and 55 per cent lower than similar-performing gyratory or jaw crusher options, in an overall lighter package. At the same time, the ERC is highly productive and energy-efficient. Its kinematics with a constantly large stroke promote a more profound crushing intensity and higher throughput rates. High inertia moments in the roll and flywheels enhance the ERC’s energy efficiency. Its integrated pre-screening device allows for efficient bypassing of fines to significantly reduce power consumption, compaction risk and the wear rate of crushing tools. The steady rotation of the freely rotatable crushing roll, when exposed to feed material, results in exceptionally uniform wear and
high utilisation of crushing tools. The symmetrical arrangement of the eccentrically moved crushing roll allows for easy balancing, so foundation forces and vibrations are reduced to a minimum. As a result, the ERC is particularly suitable for use in semi- or fully mobile applications. Smart control is another decisive advantage. Thyssenkrupp’s patented hydraulic gap setting/retraction system allows for safe and simple automatic adjustment of the gap, liner wear compensation and release of tramp metal or other non-crushable material content. Further, the ERC is equipped for Industry 4.0, incorporating a comprehensive monitoring system that allows for local or remote control and the automation of equipment parameters from the crusher’s display. In addition, an optional thyssenkrupp data acquisition system offers reliable recording and storage of relevant operational data for trouble-shooting, condition monitoring and preventative maintenance.
OPERATING PRINCIPLE Material is fed into the crusher by an apron feeder, push feeder or the like. Fine particles in the feed are screened out by the integrated Quarry April 2019 23
