New projects designed to improve process quality and efficiency are being considered in an ever more stringent manner these days, within the context of overall equipment efficiency (OEE), return on investment (ROI) and risk. Hence, securing the CAPEX, and indeed the engineering resource, for these new projects is harder than ever. Any investment must be rigorously justified on its ability to deliver towards increasingly short-term manufacturing aims, with reduced production cost and HSE compliance being key drivers for change. Against this backdrop, the development of process automation continues. Automating process analysis and control simultaneously improves profitability and reduces risk. However, those considering an investment need hard figures rather than warm words. A realistic projection of return on investment is essential, as is confidence in the technology.
Particle size is routinely a critical variable for solids processors, exerting a defining influence on product or in-process performance. Laser diffraction particle size analysis is now the standard in many sectors, with real-time systems providing measurement, monitoring and control for particle ranges from 0.1 to 1000 microns
The maturity of laser diffraction technology lowers the technical risk associated with its in-process adoption. By accessing the necessary expertise, and taking up commercial opportunities for analyzer trials, companies can develop substantial reassurance that the technology will deliver. The direct transfer of specifications from lab to process, or off-line to on-line also offers reassurance. Hence, technical risk can be reduced to a very low level. This leaves the issue of return on investment.
The most immediate and direct savings produced by automating analysis are those resulting from reductions in manpower requirements. These alone may give an acceptable project payback and are easy to quantify. Depending on the process, reducing the risk of exposure associated with manual sampling and measurement may also be crucial. Taking automated real-time measurement solely as a monitoring tool it is more efficient, less expensive (on a day-to-day basis) and far safer than the manual alternative.
But to consider on-line systems simply within the context of more efficient process monitoring fails to fully exploit their potential. Real-time measurement provides a high-integrity, continuous data stream with which to drive automated control.
Automating control locks in best operating practice and converts a fixed process to one that is responsive to change. A well-tuned automated process will drive the plant swiftly towards consistent production of a defined product specification and maintain steady state operation to exacting tolerances, with minimal manual intervention. While other variables may change (such as raw material consistency, feed rate, mill performance, and wear), the automated solution adjusts to maintain the specified particle size distribution and the highest product quality.
In estimating and maximizing the return from an investment in on-line analysis it pays to be imaginative but realistic. Ample case study literature demonstrates that the technology offers the potential for successful automation: highly consistent steady state operation and rapid transition times. Typical benefits include: reduced energy consumption; less waste; better product quality; higher plant throughput; rapid start-up/product changeover; and instant upset detection. Process engineers need to consider for their specific plant and process what the value of moving closer to ‘ideal’ operating conditions could add. OEE is one way to analyze these benefits at many levels, from a single unit of operation to dedicated production lines, and to the entire plant itself. Pursuing such strategies ensures rigorous and confident project justification and the fullest exploitation of the resulting installation.
Jeff DeNigris is sales manager, process systems, Malvern Instruments. DeNigris graduated in 1989 with a BSME degree from Widener University - College of Engineering in Pennsylvania and has spent much of his career in the manufacturing sector with top OEM suppliers of capital equipment. He joined Malvern Instruments in 2005 as national sales manager - process systems to focus on supplying on-line real-time particle size analyzers to the pharmaceutical, fine chemical, mineral, toner, and cement markets.