The screen motion analyser’s primary role is to check that vibrating screens are operating correctly.

It does this by assessing vibrating stroke, lateral displacement and operating frequency, all necessary parameters to ensure screen performance and efficiency are optimised.

The concept was initiated more than a decade ago by CSIRO Energy Technology as part of an Australian Coal Association research project to improve preparation plant vibrating screen performance.

A team led by CSIRO Energy Technology project leader Mike O’Brien produced a prototype that was then developed into a commercial product by Ludowici and others.

The screen motion analyser does not require specialist training to operate and can be used safely without impacting production.

It is fixed to the screen using magnets, records vibration simultaneously in three planes – horizontal, vertical and lateral – and sends vibration data to a smartphone via Blue Tooth.

The unit calculates and displays screen operating frequency, vibrating stroke and lateral displacement and can save files for future analysis.

O’Brien said previous methods of measuring strokes and driven frequency – stroke cards and stroke gauges – were not reliable.

“The stroke of the screen is important as it relates to the screen’s capacity to move material from the inlet end to the discharge end,” he said.

“If this movement is not linear, it can cause hold up issues and material surging.

“Uneven distribution of the feed onto the screen deck can cause a deviation in the motion across the screen, leading to higher screen wear.

“If the frequency of the screen drifts too close to the natural screen frequency, then catastrophic failure can occur.”

Repairing screens is a time-consuming process that impacts on coal production. Besides, at $500,000 apiece, replacing screens can be expensive.

Ludowici general manager engineering Rob Angus said the screen motion analyser would give mines the ability check the operations of their screens and feeders more regularly.

Xstrata Coal manager of coal preparation Frank Mercuri said the availability of a robust and simple tool that could readily measure and record vibrating equipment motion would greatly assist in identifying issues and help eliminate excessive or unbalanced structural loadings.

“The tool will aid in the identification and rectification of inadequate screen material loading, which will not only optimise screen life but optimised screen metallurgical performance and that of subsequent downstream unit processes in the coal handling and preparation plant,” he said.

O’Brien said that in his original research he had to quantitatively measure the stroke and frequency of the screen.

An encounter with a screen supplier while he was recording this information led to the thought that a portable version would be a good idea.

This concept was further developed and can be bought from Ludowici.