Full automation with on-line particle fineness

Cement plants are becoming more sophisticated and generally are now equipped with Distributed Control Systems (DCS). As the Malvern Insitec on-line analyzer is capable of streaming particle sizing data continuously into the control system via analog or digital connection, it provides a perfect platform for automated control, bringing benefits that include:

• Labor savings with fewer staff needed to run the mill
• Much steadier operation that improves product consistency
• A much reduced risk of out-of-spec material since process performance is monitored continuously

Most cement plants implement an automatic control loop as a matter of course once an Insitec system is installed in the grinding circuit. Varying the separator speed, and possibly feed rate to the mill, on the basis of particle size data is the simplest and most usual approach. However, the very best operators control a plant using every piece of available information, each clue building a detailed view of the process that then informs decision making. The very best automated control systems are no different.

Multivariate automated control systems take data from multiple sensors across the grinding circuit, or indeed the plant, to feed a detailed sophisticated model which then controls a number of manipulated variables. Multiple data points ‘in’, often at different frequencies, multiple control actions simultaneously ‘out’. This approach delivers truly optimal control within constraints imposed by the hardware and economic indicators.

Two years ago Vulcan Materials Company upgraded its cement finishing circuit by installing an Advanced Process Control (APC) solution from Pavilion Technologies, a Rockwell Automation company, and real-time particle size analysis from Malvern Instruments. Together these solutions have transformed operation, highlighting more productive control strategies and delivering major gains. Based on energy savings alone the company estimates that the payback period for the entire project (advanced control system and on-line particle size analyzer) is less than one year.

To read the Vulcan Materials case study, click here

To find out more about Malvern solutions for real-time cement measurement, click here