Patent ID: 8629313

Claim:
A method of operating a flare assembly that receives a waste gas stream at a varying flow rate, conducts a vent gas stream to a flare tip, discharges the vent gas stream through the flare tip into a combustion zone in the atmosphere, discharges primary steam through a steam injector assembly into the combustion zone and burns flare gas in the combustion zone, comprising: a. providing a source of alternative gas; b. providing a source of primary steam; c. receiving the waste gas stream; d. determining the flow rate of the vent gas stream; e. discharging the vent gas stream through the flare tip into the combustion zone; f. igniting and combusting flare gas in the combustion zone; g. determining if the injection of primary steam into the combustion zone is necessary to achieve smokeless operation; h. if it is determined in step (g) that the injection of primary steam into the combustion zone is necessary to achieve smokeless operation, carrying out the following steps: i. shutting off the flow of alternative gas through the steam injector assembly into the combustion zone if alternative gas is being discharged through the steam injector assembly into the combustion zone; ii. discharging primary steam through the steam injector assembly into the combustion zone; iii. determining the flow rate of primary steam discharged through the steam injector assembly into the combustion zone; iv. modulating said flow rate of primary steam through the steam injector assembly into the combustion zone to achieve smokeless operation; and i. if it is determined in step (g) that the injection of primary steam into the combustion zone is not necessary to achieve smokeless operation, carrying out the following steps: i. shutting off the flow of primary steam through the steam injector assembly into the combustion zone if primary steam is being discharged through the steam injector assembly into the combustion zone; ii. discharging alternative gas through the steam injector assembly into the combustion zone; and iii. heating said alternative gas prior to discharging said alternative gas through the steam injector assembly into the combustion zone.