Abstract: The apparatus comprises an explosion chamber 1 in the form of a tube closed at one end and communicating through a discharge pipe with a powdered coating batcher while a safety pipe communicates it with a mixing chamber 9 which prepares the explosive mixture ignited in the explosion chamber 1 by a spark plug 21. Installed between the safety pipe and the explosion chamber 1 is a circular precombustion chamber 10 which surrounds said explosion chamber and communicates with its space through holes 11 in its walls 12. The end of the discharge pipe 5 mounts a jet nozzle 13 which is installed in the face of the closed end of the explosion chamber coaxially with the latter so that its outlet section 16 is arranged ahead of the holes 11 in the walls of the explosion chamber 11 relative to the open end 17 of the latter.