Cement, Energy and Environment

spotting. The drive can separate and independently control motor flux and torque producing current, allowing it to deliver full torque down to zero speed. These capabilities, coupled with precise motor speed control, allow the AC drive to handle demanding motor control applications, including applications typically reserved for DC motors. When the drive arrived at Grove, it seemed like the design called for a more complicated installation than the norm. Troubleshooting Wright contacted Rockwell Automation for assistance. The company's field service engineers provided drive strat– up services to help Wright properly programme and troubleshoot the drive application. "Rockwell Automation engineers helped us commission the drive and get everything up and running within an hour of their arrival," Wright Orecalls. "This seamless, quick transition helped reduce the time between integration and actual machine operation." By networking the drive to an existing Allen-Bradley Controllogix® programmable automation controller, Ash "Motors account for a large portion of energy consumption throughout the industry. Motor Control Solutions fully integrate motor control with the control system and can help to optimize motor performance, reduce energy consumption and increase efficiency" Grove improved operational performance, receives real-time access to crucial production data, and protects valuable assets through advanced diagnostic and protection capabilities. The integrated approach helps Ash Grove drive bottom line results across its operation by improving productivity and reducing costs. Reliability and efficiency Implementing AC drive technology gave Ash Grove reliable motor control, financial savings and improved asset protection. "Maintaining the electrical equipment in a facility that produces cement around the clock and powers operations with nearly 1000 motors is demanding," says Wright. "The reliability of drive technology not only gives me peace of mind as an electrical engineer; it also leads to increased production and over 90 per cent uptime." The application knowledge of the service provider's engineers, combined with the drive's technological capabilities, helped Ash Grove save money. "Besides costing less than half as much as a medium voltage drive, using a low voltage AC drive in this application helps save money on maintenance and energy consumption, and just gets the job done better," Wright r.onfirms. Unlike the previous generator, smooth variable frequency drive technology helps reduce mechanical wear on the equipment, as well as the time and money spent on maintaining the motor. Instead of conducting annual motor maintenance, the new drive will require far less upkeep and rewinding of the motor - if any at all. The ability to operate AC drives at very low speed for controlled positioning eases the spotting process required for regular ball mill maintenance. "We believe in maintaining motors for the long run," Wright says. "It saves us more money to dedicated our efforts toward protecting these motors instead of running them until they break." In addition to spending less money on motor and gearbox maintenance, and equipment replacement, Ash Grove reduced power consumption. "In the past, we ran the generator's motor during the spotting process," Wright says. "Unlike the generator, the variable frequency drive consumes much less electrical power while we service the mills, which resulted in energy savings". To protect its investment in motors technology, Ash Grove developed an overall maintenance strategy that supplements internal efforts with support from Rockwell Automation as needed. "The innovative technique of using a low voltage AC drive to power a medium voltage application proved to be a reliable, cost– effective solution," Wright said. Model predictive control (MPC) technology Vulcan Materials Company constantly works to provide the highest quality product, while reducing material and energy costs and meeting stringent environmental regulations. The company also strives to continually achieve process efficiencies and tighter control through its existing equipment and technology infrastructure. However, when faced with the limitations of a manual approach to optimizing its finishing circuit, the Florida Rock mill moved to automated process control with Pavilion Technologies. 23