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58 E&MJ; • JUNE 2014 www.e-mj.com Optimizing Crusher Control Crushers are energy-hungry pieces of equipment, so optimizing drive and control systems makes good economic sense By Simon Walker, European Editor At the end of last year, the Australian provider of design, automation, control, instrumentation, electrical engineering and process optimization systems, MIPAC Engineering, announced the award of a significant contract from Germany's Tenova Takraf. MIPAC has been tasked to design and configure the electrical, instrumentation and control for three semi- mobile crushers at a major project in Western Australia's Pilbara region. According to the company's business development director, Alan Thorne, it had been liaising with Tenova Takraf about the project since 2011. "MIPAC's experience in crusher control systems and other mining operations made us a natural choice to undertake the crusher control design and configuration," he said. "The work will be completed by August." The crusher control system is PLC- and SCADA-based, with MIPAC developing the functional specification for the control philosophy in conjunction with Tenova Takraf. The design involves plans for one crusher that will then be replicated for the other two. This will significantly reduce engineering costs, according to MIPAC project manager, Ashish Mahajan, who said, "MIPAC will also be involved in HAZOP studies and machine safety studies conducted by Tenova Takraf as part of the development of the crusher operational philosophy." This example is just one of a growing body of practice found- ed on ensuring that crushers run at their most economical set- ting, while at the same time maintaining consistent throughput. All stages of comminution are energy-hungry, and while energy usage rises in line with the fineness of reduction, a lot can be gained from optimizing each stage of the crushing and grinding process. Hence ensuring that the drive and control systems installed on crushers and mills are doing the job for which they were designed makes strong economic sense. The 'Brain' in Control According to Sandvik, the intelligent drive and control systems in its CH series of cone crushers and CG series of primary gyra- tories enable real-time performance management, most tangi- bly equaling maximized crusher performance and productivity. The company explained that the "brain" in its crusher control system, the Automatic Setting Regulation system (commonly known as ASRi), protects the crusher from overload and con- stantly monitors the power draw, the hydroset pressure and the mainshaft position (and thus the closed-side setting—CSS) in real time. It adapts the crusher's settings in real time to match feed-curve variations as well as variations in feed material hard- ness, thereby ensuring consistent maximum performance, Sandvik added. By continuously measuring and automatically compensating for cone crusher liner wear, the ASRi allows customers to fully utilize crusher liners and schedule liner replacements to coin- cide with scheduled maintenance stops, Sandvik said, while noting that the ASRi also allows quick and easy remote calibra- tion, even from a control room. Big benefits can be won by controlling a crushing plant carefully. (Photo courtesy of Sandvik) C R U S H E R S "The objective of a crusher control system is to maximize the crusher yield while protect- ing and ensuring that the crusher should not suffer from premature failures." Professor Magnus Evertsson and others, Chalmers University of Technology EMJ_pg58-63_EMJ_pg58-63 6/3/14 3:06 PM Page 58