Sep 22 2006
Implementation of a novel control strategy, underpinned by on-line particle size data measured using a Malvern Insitec, has transformed process efficiency at a metal powder production facility. Prior to installation of the new system large fluctuations in particle size were a regular occurrence and the particle size distribution of the finished product was very broad. With the new control strategy in place, particle size is controlled effectively and automatically. A 75% reduction in particle size distribution width has been achieved, mill throughput has been increased and manpower requirements have been dramatically reduced. The mill is now operating close to its performance limits.
Mill loading is a particular issue at the site as the metal granulate feed is so light. Conventional mill fill measurement methods are not appropriate and the mill can be easily over-filled. The downstream fluctuations directly impact product quality.
With the implemented control strategy throughput is automatically manipulated in response to particle size. If particle size is too low throughput is increased and vice-versa. Product from the mill is separated using a classifier that returns oversized material. A second control loop manipulates the speed of this classifier to maintain a set recycle flow rate. The two loops work in tandem to deliver vastly improved overall performance.
Automated control loops are only possible if the required variables can be consistently and reliably measured. The Insitec particle size analyzer is designed specifically to meet the requirements of continuous industrial operation. It has extremely high reliability, requires little maintenance, needs no calibration and is easily integrated with existing plant.