Determination of correlation between specific energy consumption and vibration of a raw mill in cement industry

Abstract

In cement industry about 110 kWh of electrical energy is consumed to produce one ton of cement and about 26% of the total electrical power is used during farine production. In this study, certain measures are implemented in an existing raw mill in a cement factory and the specific energy consumption of the unit is calculated to be 25.52 kWh/ton farine. The effects of ball charge rate, moisture content and size of feeding materials on vibration of main driving motors are investigated. The data collected over a 12-month period indicate that vibration directly related to the specific energy consumption (SEC) of the unit. The vibration on the motors of the raw mill is decreased by about 12% as the moisture content and size of the raw materials decreased by half. By this way, specific energy consumption of the unit decreased to 25.19 kWh/ton farine. Keeping the vibration values on the main driving motors less than 4 mm/s by periodical maintenance, the specific electrical energy consumption of the mill has reduced by 2.16% to 24.97 kWh/ton farine which corresponds to a saving of 0.55 kWh per ton of farine production.

DETERMINATION OF CORRELATION BETWEEN SPECIFIC ENERGY CONSUMPTION AND VIBRATION OF A RAW MILL IN CEMENT INDUSTRY

Abstract

Çimento endüstrisinde 1 ton çimento üretimi için yaklaşık 110 kWh elektrik enerjisi tüketilmektedir ve toplam elektrik enerjisinin yaklaşık %26’sı farin üretimi sırasında harcanmaktadır. Bu çalışmamızda bir çimento fabrikasında çalıştırılmakta olan farin değirmeninden belirli ölçümler alınmış ve ünitenin özgül enerji tüketim değeri 25,52 kWh/ton farin olarak hesaplanmıştır. Bilye doluluk oranı, malzeme nem miktarı ve üniteye beslenen hammadde ebatlarının ana tahrik motorları üzerindeki titreşim değerlerine olan etkisi incelenmiştir. 12 ay boyunca düzenli olarak toplanan veriler, değirmen titreşim değerlerinin ünitenin özgül enerji tüketim (ÖET) değerlerini doğrudan etkilediğini ortaya çıkarmıştır. Hammaddenin içerdiği nem oranının yarıya düşürülmesiyle ana tahrik motorları üzerindeki titreşim değerlerinin yaklaşık %12 oranında azaldığı tespit edilmiştir. Bu sayede, ünitenin özgül enerji tüketimi 25,19 kWh/ton farin değerlerine düşürülmüştür. Düzenli bakımla ana tahrik motorlarındaki titreşim değerlerinin 4 mm/s değerinin altında tutulmasıyla, değirmenin özgül enerji tüketim değeri %2,16 düşerek, 1 ton farin için yaklaşık 0,55 kWh’lik bir enerji tasarrufunu sağlanmış ve değirmenin enerji tüketimi 24,97 kWh/ton farin değerine düşürülmüştür

Keywords

• Çimento, Farin değirmeni, Titreşim, Enerji, Öğütme

References

1. Fuersteneau DW, Abouzeid AZM. The energy efficiency of ball milling in comminution. Int. J. Miner. Process 2002; 67:161–185.
2. Katsioti M, Tsakiridis PE, Giannatos P, Tsibouki Z, Marinos J. Characterization of various cement grinding aids and their impact on grindability and cement performance. Construction and Building Materials 2009; 23:1954-1959.
3. Tsakalakis KG, Stamboltzis GA. Correlation of the Blaine value and the size of the cement particle size distribution. Zement-Kalk-Gips 2008; 61:60–68.
4. Schneider M, Romer M, Tschudin M, Bolio H. Sustainable cement production present and future. Cement and Concrete Research 2011; 41:642–650.
5. Hendrik G van Oss, Padovani AC. Cement Manufacture and the Environment Part II: Environmental Challenges and Opportunities. Journal of Industrial Ecology 2003; 7: 93-126.
6. Worrell E, Nathan M, Price L. Potentials for energy efficiency improvement in the US cement industry. Energy 2000; 25:1189-1214.
7. Atmaca A, Kanoglu M. Reducing Energy Consumption of a Raw Mill in Cement Industry. Energy 2012; 42:261-269.
8. Hendriks CA, Worrell E, Jager de D, Blok K, Riemer P. Emission Reduction of Greenhouse Gases from the Cement Industry. Greenhouse gas control technologies conference paper, 2004.

9. Schuer A, Leiman A, Ellerbock HG. Possible ways of saving energy in cement production. Cement Kalk Gips 1992; 7: 175-182.
10. Utlu Z, Sogut Z, Hepbasli A, Oktay Z. Energy and exergy analyses of a raw mill in a cement production. Applied Thermal Engineering 2006; 26: 2479-2489.
11. Sogut Z, Oktay Z, Hepbasli A. Investigation of effect of varying dead-state temperatures on energy and exergy efficiencies of a Raw Mill process in a cement plant. International Journal of Exergy 2009; 6: 655-670. [12] Behera B, Mishra BK, Murty CVR. Experimental analysis of charge dynamics in tumbling mills by vibration signature technique. Minerals Engineering 2007; 20: 84–91.
12. Kolacz, J. Measurement system of the mill charge in grinding ball mill circuits. Minerals Engineering 1997; 10: 1329–1338.
13. Gugel K, Moon RM. Automated mill control using vibration signal processing. In: IEEE Cement Industry Technical Conference. Charleston. United States. 29 April–2 May 2007; 1: 17–25.
14. Zeng Y, Forssberg E. Vibration characteristics in a large-scale ball mill. Scandinavian Journal of Metallurgy 1993; 22: 280–286.
15. Huang P, Jia MP, Zhong BL. Investigation on measuring the fill level of an industrial ball mill based on the vibration characteristics of the mill shell. Minerals Engineering 2009; 22: 1200–1208.
16. Greer WL, Johnson MD, Morton EL, Raught EC, Steuch HE, Trusty CB Jr. Portland cement. In: Buonicore AJ, Davis WT, editors. Air Pollution Engineering Manual. New York: Van Nostrand Reinhold, 1992.
17. Tiggesbaeumker P, Williams J. Large Mills for Dry Raw Material and Clinker Grinding. IEEE, Transactions On Industry Applications 12, 1976.
18. International Energy Agency. IEA, CO2 emissions from fuel combustion, Highlights. CO2 emissions per kWh. IEA press, 2011. pp 39-40.