- February 14, 2012
- Malvern Instruments Inc.
- Case Study
Particle size data is used to automatically vary the speed of the classifier used to separate the milled cement into a fine product stream and a coarser recycle.
February 14, 2012 - Cement producer Sacci is using an Insitec on-line laser diffraction particle size analyzer from Malvern Instruments at its site in Tavernola, Italy, for process control of the cement mill, to enhance product quality and reduce the time that operators spend on process control. The use of real-time particle size data to automate the milling circuit that produces finished cement has liberated operators to focus on higher value work. At the same time it has significantly improved product consistency. “Before we installed the Insitec we relied on off-line particle size data to control the milling circuit,” observed Alessandro Mazzucƒão, Plant Quality Manager. “The quality of the data was fine but the frequency of measurement, every two hours, wasn’t really high enough. Quite large changes were made after each measurement and so our product was not as consistent as we would have liked.” At the plant, particle size data are used to automatically vary the speed of the classifier used to separate the milled cement into a fine product stream and a coarser recycle. In the past this control loop was driven by data measured in the laboratory using a Mastersizer 2000 laser diffraction particle size analyzer (Malvern Instruments). Now the data come from the on-line Insitec system. “Our experience of Malvern was very positive,” continued Alessandro Mazzucƒão, “so we expected the Insitec to work well. It’s a robust, well-designed instrument and over the three years it’s been running, reliability has been excellent. We need to clean the optical window from time to time, but other than that it needs almost no maintenance. Being able to rely on this level of performance is crucial for 24/7 operations such as ours. Production has become far more consistent than when we relied on the off-line analysis of single samples, with much smaller process changes now made automatically on a more frequent basis.” The Insitec is installed on the elevator conveyor that carries finished product to the storage silo. It automatically samples the cement via a two-stage sampling system which ensures a representative cut of the very large process flow. A full particle size distribution is produced every five seconds but rolling average data are used for process control. This continuous data stream gives much finer control of the classifier, which is now varied within far tighter limits compared with using off-line measurement, leading to a more consistent product. Automating sampling, analysis and control has saved considerable operator time - time that is now being used to further other production goals. About Sacci S.p.A. Sacci Group cement production and sell from 70 years. Six plants Testi-Greve in Chianti (FI), Castelraimondo (MC), Cagnano Amiterno (AQ), Livorno (LI), Tavernola Bergamasca (BG) e Pescara (PE) in Italy. At the end of 2008 buy the plants of Business Unit Italy of Lafarge, cement plants Tavernola Bergamasca (BG) e Pescara (PE) and Beton plants. Now in the Group work 800 people in six cement plant and 40 Beton plants. About Malvern Instruments Malvern Instruments is a market leader in measuring performance controlling material properties. These include particle size, particle shape, zeta potential, molecular weight, size and conformation, rheological properties and chemical identification. Malvern delivers the systems, support and expertise that ensure the analytical integrity and productivity needed to drive research, development and manufacturing.Learn More
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