Improving the Performance of Loesche´s Vertical Mill 3 at Nuh Cimento in Hereke with LMmaster
IMPROVING THE PERFORMANCE OFLOESCHE’S VERTICAL MILL 3 ATNUH CIMENTO IN HEREKE WITHLMmasterNuh Cimento Sanayi expectations exceeded by Loesche
The challenge:With the company’s own quarry in connection with a private harbour Nuh CimentoSanayi, a Turkish Cement company, has two outstanding location factors for cementproduction. The resulting extremely short transport paths in the Hereke plant are asignificant reason for the success of the company. To continue to expand its posi-tion in the international cement market, Nuh Cimento Sanayi decided to increasethe plant efficiency. To achieve this goal, Nuh Cimento has invested in the Loescheautomation solution LMmaster. The solution was applied first in the raw material millRM3, a vertical roller mill LM 63.4 with a capacity of 505 t/h and a specific powerconsumption of the main drives (mill motor, mill fan and classifier) of 15,8 kWh/t.The mill is a vertical roller mill from Loesche.“We are very satisfied with the Loesche LMmaster and the process experience theyare bringing into this solution. We always thought that our RM3 is operating at theperformance limit. This benefit shows that process knowledge and experience arethe most important assets to provide MPC solutions.”Mr. Oguz Aydinc, Cement Production Manager at Nuh Cimento SanayiIn November 2010 the decision was made to optimize the system with the helpof LMmaster. The big challenge for the engineers of Loesche was to optimise analready good system running and to increase the performance to the technicallyachievable high end.The client: Nuh Cimento SanayiFounded in 1966, Nuh Cimento Sanayi company successfully produces in-housequarry cement for the local Turkish market and for export. The high export quotawill force the manufacturers to continue competitive and efficient production, dueto the highly competitive market. The plant offers ideal logistics for competitivemanufacturing.The plant produces with conventional control technology and an efficient mill ata high level of raw meal for the subsequent production of cement. Nuh CimentoSanayi’s goal was to increase the throughput of the mill with reduced energy useand increased the availability of the system. Precisely for this request, the processoptimization of Loesche grinding mills, the LMmaster automation product wasdesigned and developed.MPC – highly efficient and powerful technology forLoesche customersIt is the “standalone” real-time process optimization solution for an optimal opera-tion of the Loesche grinding systems. The focus of LMmaster is on efficient perform-ance, increase mill throughput, ensuring product consistency and increased plantavailability. Compared to competitors in the market there is no additional engi-neering work necessary after the implementation of the solution.An MPC (Model Predictive Control) like LMmaster is based on a specific math-ematical model for imaging of dynamic processes with multiple interacting vari-ables. With the model-based control all PID-controllers are contained in one modelto consider the process as a whole with the respective influences of each variable.LMmaster calculates the future state of the system and uses these values to definenew operating points of each controller. For the calculation of operating points asthe current set points, the current actual values, the disturbances as well as histor-ical data are taken into account. This model calculates the new set points for thePLC, which derives from the necessary control variables and outputs. This happenscontinously and in real time to avoid any delays using the LMmaster.
Through consideration of future values the early stabilization counteracts theeffect of the process. This is a continuous optimization of the operating point ofthe respective control of the process. The optimal operating point and the asso-ciated stabilization have smoother operation resulted in the impact of consistentproduct quality and lower specific energy consumption. Similarly, the throughput ofthe system was increased.The results:“LMmaster is taking over the grinding process and leaves more time for our opera-tors to concentrate on other processes.”Mr. Ismail Dogan, Clinker Production Engineer at Nuh Cimento SanayiThrough the use of LMmaster, all expectations of Nuh Cemento are satisfied andeven exceeded. The application at Nuh Cimento Sanayi in Hereke was imple-mented successfully and improved the specific energy consumption with increasingthroughput significantly. The plant now runs more stable and smoother with a higheravailability of the grinding system and a reduced variation in product quality.Due to the Nuh Cimento owned power plant on site the reduction of the specificenergy consumption is combined with reduced CO2 emissions.The key benefits of the optimization are:• Increase in capacity of 5.8 % (29.4 t/h)• Reduction in specific power consumption of 4.95 % (0.78 kWh/t)• Improved consistency in operations• Reduced mill vibration by 17.25 % (1.04 mm/s)• LMmaster controller utilization greater than 90 %• Sustainable relief of the operator Specification or Limit before Model with Model Predictive Control Predictive Control and OptimizationFigure 1: Working principle of MPC with LMmaster
Variable Time- Min. Max. Mean Standard frame Devia- tion Total Before 470.0 538.2 506.7 8.38 fresh Optimi- feed zation After 470.3 569.0 536.1 8.19 Optimi- zationTable 1: Statistics of total fresh feed t/h during baseline andevalution period Variable Time- Min. Max. Mean Standard frame Deviation Specific Before 6.02 21.4 15.75 0.858 Power Optimiza- Cons. tion Figure 2: Mill differential pressure before implementation After 6.84 20.6 14.97 0.74 Optimiza- tionTable 2: Statistics of specific power consumption during baselineand evaluation period Variable Time- Min. Max. Mean Standard frame Deviation Mill Vibra- Before 0.3 29.5 6.03 1.69 tion Optimza- tion After 0 34.3 4.99 1.41 Optimiza- tionTable 3: Statistics of mill vibration during baseline and evaluationperiod Figure 3: Mill differential pressure after implementationThe LMmaster was already online 3 months after the Due to the use of LMmaster on a separate industrialkick-off and pays back very fast. Due to the good PC with its own software platform, there is no securityperformance the ROI is less than 12 months. threat to the installed control system. Another safety aspect is the “switch back” option that allows the oper-“We are looking forward to installing LMmaster also ator to smoothly switch to the original PLC/DCS mode.in other Loesche Mills in our plant.” Mr. Ismail Dogan, However, the switch back option has never been used …Clinker Production Engineer at Nuh Cimento Sanayi Conclusion: Loesche implemented a turnkey solution without any further operational expenditures and a ROI of below 1 year. This is allowed by a short implementation time of 2–3 months without any shutdowns and interruptions of the grinding system. LMmaster delivers significant sustainable improvements to the Loesche Mill. Hansaallee 243 D-40549 Duesseldorf Tel. +49-211-5353-0 Fax +49-211-5353-500 www.loesche.com