METALSPRITZVORRICHTUNG

摘要

PCT No. PCT/GB92/01128 Sec. 371 Date May 2, 1994 Sec. 102(e) Date May 2, 1994 PCT Filed Jun. 22, 1992 PCT Pub. No. WO93/00170 PCT Pub. Date Jan. 7, 1993.A stream of molten metal particles in a metal spraying apparatus is deflected from side to side by gas issuing from two nozzle blocks disposed at diametrically opposite sides of the stream. Gas is supplied to the two nozzle blocks (13) alternately under the control of a rotary valve (19) having a stator (18) and a cylindrical rotor (24). The rotor has two circumferentially extending grooves (26) whose cross-sectional area varies in predetermined manner and each of which serves to provide and cut off communication between an inlet port (21) for gas under pressure and an outlet port (23) which is circumferentially aligned with the inlet port and which leads to an associated one of the nozzle blocks. The areas of the inlet and outlet ports are each greater than the maximum cross-sectional area of the groove, so that the quantity of gas reaching the nozzles at each instant is determined by the instantaneous effective area of the groove (26). The limiting quantity of gas emitted from the nozzles corresponding to maximum deflection of the metal particle spray is however determined by the total area of the nozzles in the block. An increase in the quantity of gas issuing from the nozzles increases the deflection of the metal particle stream.