Powder coatings applied by detonation - in spray gun using ignited mixt. of oxygen and acetylene

摘要

The appts. consists of a gas distributor (a) fitted with two inlet valves (b, c) for gases (g1, g2) forming an explosive mixt. in a mixing chamber (a1) leading to a gun barrel. The gas mixt. flows down the barrel, which is fitted with an igniter, followed by an inlet for the powder. Each valve (b, c) contains a floating disc; and the distributor (a) has a third inlet valve (d) actuated by a solenoid and supplying a rinsing gas (g3) with a higher pressure than gases (g1, g2). When gas (g3) is fed into distributor (a), it forces the floating discs against the inlet pipes for gases (g1, g2) so the latter cannot enter chamber (a1). In an embodiment, gases (g1, g2) are oxygen and acetylene; whereas gas (g3) is N2 or Ar. Used e.g. for coating compressor- or turbine- blades for aero-engines; magnetic recording heads; or rolls for working metals.