Apr 22 2005
At Castle Cement’s Padeswood Works (Wales, UK) a significant improvement in mill control has been achieved through the exploitation of data generated by a Malvern Insitec on-line particle size analyzer. In 2003, Castle Cement (the UK arm of HeidelbergCement Group) switched from off-line to on-line particle size analysis at its Padeswood Plant, with the aim of improving mill control during both steady-state and transient operation.
The plant selected an Insitec system, favouring its robust design and proven operational performance in cement facilities throughout the world. Using the on-line data stream produced, product changeover times have been reduced from around 3 hours to under 30 minutes. Product consistency has been improved, and overgrinding has been minimized.
The Insitec system has easily handled the arduous demands of the application - dust, vibration, abrasive product. Installation of the system was completed in the four days that had been estimated and since then has consistently and reliably generated data with negligible maintenance. It is now an established tool for product and process control and further installations are planned both at Padeswood and throughout the group.
An additional benefit of the new installation is the insight it has afforded into the milling operation. As part of Castle’s drive to reduce carbon emissions, raw materials requirements, wastage and energy consumption, limestone was added to the finish mill feed. Off-line composite analysis indicated that simple addition to the clinker feed hopper would be adequate, but on-line data showed that in practice this resulted in rapid grinding of the relatively soft limestone and little blending. An alternative optimized limestone feed was subsequently selected.
The Malvern Insitec on-line particle size analyzer has been developed to meet the requirements of applications in a wide range of industries. The Insitec system uses industry standard ensemble laser diffraction to rapidly measure complete volume-based particle size distribution data. It is not affected by either dust or vibration and needs no external calibration. Reliability is extremely high and installation times low. For cement producers a fully integrated sampling, analysis and data presentation option for real-time fineness monitoring has been developed which fully addresses the needs of the industry.
Cement producers typically install Insitec systems to monitor final product grade but they can also be used effectively in other parts of the plant to analyze, for example, feed to the kiln. By 2007, it is anticipated that more than 500 Insitec analyzers will be operational in powder processing plants worldwide, delivering true on-line analysis. More than 100 of these will be installed in cement finish mills.
For more information on particle size analysis, click here.