BrainWave Control solutions for recycled paper - Andritz

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The challenge: To fi nd cost-effective technologies to upgrade your paper mill The solution: Advanced control with BrainWave Perhaps there is no upgrade that stabilizes production and reduces costs like BrainWave—without a large capital investment. BrainWave is easy to install and set up, can be retrofi tted to existing processes, and delivers a quick return on investment. BrainWave is a patented controller, proven since 1992, that can be installed as an upgrade to any DCS or PLC system. It outperforms traditional PID control because it controls long dead-time processes, reacts before being pushed off-target, handles nonlinear responses and is both an adaptive and predictive controller. It builds its own live models during normal operations and accurately forecasts the process responses to changes in production rates or set points. BrainWave Success story: Multi-stage bleaching In this mill, BrainWave measures the incoming brightness from the thickening and fl otation processes and brightness after the bleaching tower. Based upon the deviation of incoming brightness and the delay time, BrainWave calculates the chemical dosage required ahead of the pulp (feedforward principle) in order to keep the fi nal brightness set point. This ability to model and forecast the process is a huge advantage over traditional PID and manual controls which cannot cope with continuously changing process parameters. As a result, BrainWave minimizes the chemical dosage required to obtain the fi nal brightness target and stabilizes the overall quality Page 2 takes corrective action before you produce off-spec product to keep your process stable. Return on investment is measured in months, not years. BrainWave is controlling over a thousand loops in factories around the world and saving customers millions of US dollars per year. In combination with other ANDRITZ technologies, such as DotScan and FiberVision, BrainWave delivers chemical and energy savings—and improved quality. of the bleached pulp. There has been a noticeable reduction in COD discharge to the effl uent system. BrainWave control also delivers several signifi cant side benefi ts. In addition to chemicals savings, the mill has documented notable BrainWave can be applied to virtually any pulp or paper production process. It comes with its own server that can be easily linked to existing DCS or PLC systems through a standard OPC connection, acting as an overlay to the existing control. Once in operation, it can control several process groups without new investments in hardware. Set point 1 BrainWave Set point 2 BrainWave model 1 BrainWave model 2 production increases and yield improvements (as a result of using less NaOH, minimizing silicate, and obtaining stable control of the process). The reduction in NaOH also lowers the COD load in the effl uent— providing relief for the water treatment plant, with signifi cant improvement in environmental impact.
Success story: Bleaching of deinked pulp Before: This DIP line in China has a capacity of 1,200 bdmt/d. Before installing BrainWave, the mill controlled brightness by applying bleaching chemicals in a ratio tied to production rate. Operators tried to manually compensate for variations in furnish brightness and process disturbances in real time. This became a time-consuming task: monitoring brightness readings around the clock and modifying chemical dosing to try to keep to the targeted brightness. Most of the time, the operators overshot the brightness target to be on the safe side, and there was high consumption of costly bleaching chemicals. After: Within a very short time after installing the BrainWave controller, the bleaching process stabilized and the results were signifi - Brightness % ISO 1,2 1 0,8 0,6 0,4 0,2 0 64 63 62 61 60 59 58 57 56 55 55,3 55 241 236 231 226 221 216 211 206 201 196 191 186 181 176 171 166 161 156 151 146 141 136 131 126 121 116 111 106 101 96 91 86 81 76 71 66 61 56 51 46 41 36 31 26 21 16 11 6 55,9 55,6 56,5 56,2 56,8 BrainWave 57,4 57,1 58 57,7 58,6 58,3 Operator control LAB Brightness Line 1 May 5 May 8 May 11 May 14 May 17 58,9 59,5 59,2 60,1 59,8 Results n Reduction in fi nal brightness deviation = 71% n Increase in overall brightness = 1 pt Iso n Reduction in bleaching chemicals = $1/t (annual savings ~ 400,000 USD) n Return on investment in just a few weeks cant (see sidebar). In addition, the DIP plant operators were now freed up to monitor the overall process and ensure the proper performance of the equipment. 60,7 60,4 Figure 1: Normal distribution, operator versus BrainWave (final LAB brightness) BrainWave control LAB Brightness Line 2 Standard Deviation = 1.4 Standard Deviation = 0.41 Figure 2: Lab brightness data (May 5 to June 1, 2010) 61 Mean St.Dev ------------------------------------------------- Operator 59.65 1.42 BrainWave 58.2 0.41 ------------------------------------------------ Improvement 2.28% 70.94% (1.3 ISO) 61,6 61,3 Operator 62,2 61,9 62,8 62,5 63,1 63,7 63,4 64,3 64 Results, May 2010: Achieved in a 1,200 bdmt/d Chinese DIP line When BrainWave was first installed, a short time was needed for the controller to collect process data and create a control model. Figure 2 shows the immediate impact after just a few hours of BrainWave being activated. After a few weeks for optimization and model refinement, BrainWave demonstrated its full capabilities to minimize process disturbances, save chemicals, and reduce operating costs. Paper machine operators noted that the final product quality is more uniform due to fewer variations. The lower consumption of bleaching chemicals also contributed to less COD load in the DIP water circuits—which positively impacted the water treatment and environmental aspects of the mill. Benefi ts n Stable process—on-spec production n Signifi cant reduction in chemical, energy, and raw materials costs n Quality improvements n Easy implementation, with fast payback Page 3
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BrainWave Control solutions for recycled paper - Andritz

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