Abstract: The present invention relates to a process for treating combustible exhaust gases containing poisonous and combustible component gases such as silane and so on, and a combustion system therefor. In the combustion system, the combustible exhaust gases are burnt by downward flames generated from a coaxial, fourfold-pipe burner wherein the flow rates of primary and secondary air are regulated, thereby preventing fine particles of oxides such as silicon dioxide resulting from the combustion of silane, etc. from being deposited onto the nozzle of said burner and allowing deposites, if any, to peel off immediately. Thus, there is no fluctuation in the pressure of the a combustible exhaust gas path, so that constantly stable and continuous combustion is achieved with no difficulty. Removal of dust contained in the exhaust gases comprising fine particles of silicon dioxide, etc.

Abstract: A burner for flame-spray coating, being capable of sufficiently high flame temperature and being capable to flame-spray powder material of high melting point by using such fuel gas as C.sub.3 H.sub.8 or C.sub.4 H.sub.10 with high efficiency of deposition, having a gas-powder stream supplying conduit connectedly arranged at the rear portion of a pre-mix combustion chamber, from where gas-powder stream being jetted into the chamber, characterized that at least a series of auxiliary combustion gas (oxygen, oxygen enriched air) supplying passages are annularly provided on the conical wall face of said chamber with the direction of converging toward an opening for flame jet and the axis of the pre-mix combustion chamber.

Abstract: A method for supplying raw powder material such as metal, intermetallic compound or ceramics to a spray coating burner wherein fuel gas or auxiliary combustion gas or their mixed gas is used as jet gas, any one of these gases is introduced under control of the flow rate thereof into a suction chamber of an ejector to serve as suction gas whereby the supply amount of said raw powder material to be fed to said spray coating burner can be controlled.