Flare-stack

Claim 1

A flarestack for burning waste gases, comprising: A plurality of modular burner elements constituting a burner unit; each of said burner elements having a plurality of combustion air tubes adapted to convey combustion air to a combustion zone, each of said combustion air tubes having a crosssectional area of not less than 1.0 cm.2 where it opens into said combustion zone and the bores of said combustion air tubes accounting for at least 25 percent of the area adjacent to said combustion zone, said combustion air tubes passing through a fuel chamber divided into a fuel outlet space which communicates with said combustion zone and which contains packing to provide a high resistance to the flow of gaseous fuel, and a fuel inlet space adapted for connection to a fuel supply and which contains no packing material to provide a low resistance to the flow of fuel; flarestack walls projecting vertically upwardly from the edges of said burner unit; the length of a side of said burner unit being not less than 5 feet or greater than 30 feet; the height from the ground to said burner unit being a quarter to a third of the length of a side of said burner unit; and a draught fence enclosing the base of said flarestack walls and said burner unit, whereby during operation of said flarestack, air flows through said draught fence, below said flarestack walls and into said combustion air tubes of said burner unit.