Ignition of dust clouds and dust deposits by friction sparks and hotspots

Abstract

Evaluating the effectiveness of mechanical ignition sources in igniting dust clouds and deposits is a major problem when assessing the risks in powder handling plants. This paper describes the results obtained in the recent European collaborative project, MECHEX, with explosible dusts. These involved both friction and impact ignition tests with different dusts including coal, maize starch, calcium stearate, suphur and sawdust as well as hotspot tests. using both large hotspots in dust deposits and small laser heated hot particles in dust clouds. The experimental work was carried with the aim of providing guidance for inclusion in European Standards on mechanical equipment for use in potentially explosive atmospheres. Although still inconclusive, the results obtained provide further information for understanding the complex problem of frictional ignition