Abstract: An improved low pollution invisible flare burner comprises a tall stack lined with ceramic. The stack is supported above the ground level and has a wind screen surrounding the open portion below the stack floor. Primary air is introduced under pressure in a tube below and coaxial with the stack. The top of the tube contains a burner for the vented hydrocarbon gases. The top of the tube and the burner are at the level of the floor of the stack. Secondary air is introduced into the stack in the annular space between the primary air conduit and an opening in the floor of the stack. Turbulent mixing of the primary air and the vent gas, plus the availability of sufficient atmospheric air for complete combustion, plus the effect of heated ceramic in the vicinity of the flame, provide means for complete combustion of the vented gases with low emission of smoke and light.

Abstract: This is an improved smokeless flare powered by air supply to the burner at substantial velocity. The flare includes an air flow-operated damper for the purpose of preventing the back flow of flame and hot gases under adverse wind conditions. The damper consists of two semicircular plates which are hinged along the diameter of the air supply pipe and are held in a closed (transverse) position by means of tension springs. Another feature of this flare is that in the sectors between the spider arms of the burner there are baffles which are triangular in shape and have substantial longitudinal dimension. There are narrow passages between the baffles and each of the adjacent spider arms so that the air flow from the blower must pass through these restricted passages and therefore will move at a higher velocity.