Combustion apparatus

A combustion apparatus with a burner port assembly that comprises an elongated first array of main burner ports for jetting and burning a fuel gas mixture of a concentration to make main flames, the combustion apparatus further comprising:

• at least one second arrays of auxiliary burner ports for jetting and burning a further fuel gas mixture of a different concentration to make auxiliary flames;
• the second arrays of said auxiliary burner ports extending along the first array of said main burner ports;
• the burner port assembly being composed of inner and outer wall segments together with outermost bands, wherein the inner and outer segments are corrugated to define between them openings serving as the main burner ports;
• the one of said outer segments facing the corresponding one of said outermost bands so as to define between them collateral burner ports within a region in which the main burner ports are included;
• and
• the second arrays of the auxiliary burner ports comprising each a plate portion that cooperates with the corresponding one of the outermost bands in order to define between them intermediate burner ports,
• wherein a still further gas mixture to be jetted from and burnt at the collateral burner ports is either of the same concentration as that for the auxiliary burner ports or of a medium concentration between the respective concentrations for the main and auxiliary burner ports, and a yet still further gas mixture jetted from the intermediate burner ports is of another medium concentration between the respective concentrations for the main and auxiliary burner ports.