Low steam consumption high smokeless capacity waste gas flare

Abstract

A steam flare is provided that injects steam, unmixed with air into a waste gas stream at locations where the resulting accelerated steam and waste gas mixture upon exposure to the surrounding air induces a mixture of steam, waste gas and air with improved combustion and effectively complete destruction of the waste gas, and where under low-flow conditions, reduced steam and/or assist gas are required to maintain smokeless operation.

1 . A steam flare comprising a waste gas cylinder connected at an upper portion of said waste gas cylinder to a plurality of extensions that extend away from a center of said waste gas cylinder, wherein each of said extensions contain a plurality of flare gas conduits, and wherein a steam tube is located in each of said flare gas conduits. 
     
     
         2 . The steam flare of  claim 1  further comprising a ring at a top portion of said flare gas conduit and above a top portion of said steam tube. 
     
     
         3 . The steam flare of  claim 1  wherein said flare gas conduit is a tube having a cylindrical, square, rectangular, oval or complex configuration. 
     
     
         4 . The steam flare of  claim 1  wherein said steam tube comprises a single tube having branches that extend into each of said flare gas conduits. 
     
     
         5 . The steam flare of  claim 2  wherein said ring contains perforations or other surface features. 
     
     
         6 . The steam flare of  claim 1  further comprising a multiplicity of flow-reducing cones in said flare gas conduit and below a top portion of said steam tube. 
     
     
         7 . The steam flare of  claim 1  further comprising a singular flow-reducing cone in each of said flare gas conduits and below a top portion of said steam tube. 
     
     
         8 . The steam flare of  claim 1  with a curved, straight or sloped transition piece from said waste gas cylinder to said flare gas conduits. 
     
     
         9 . The steam flare of  claim 1  with a flat plate capping the waste gas cylinder. 
     
     
         10 . The steam flare of  claim 1  with a cone and a flat plate capping the waste gas cylinder. 
     
     
         11 . The steam flare of  claim 1  wherein said steam tube has a singular orifice pointing vertical. 
     
     
         12 . The steam flare of  claim 1  wherein said steam tube has two to twenty orifices pointing at an angle between zero and fifty degrees from vertical. 
     
     
         13 . The steam flare of  claim 1  with external steam tubes injecting steam between a hub metal and a combusting stream. 
     
     
         14 . A process of operating a steam flare comprising sending a waste gas stream through a waste gas cylinder to a plurality of flare gas conduits while sending a stream of steam through a tube wherein said tube extends into said flare gas conduit, mixing said waste gas stream and said steam and then causing a flame to burn as a resulting mixture of said waste gas stream, said steam and oxygen in outside ambient air. 
     
     
         15 . The process of  claim 14  wherein less than 0.09 kg (0.20 lbs) steam is used per pound of propane waste gas. 
     
     
         16 . The process of  claim 14  wherein a ring at the upper portion of the waste gas tip of said flare gas conduit comprises perforation or other surface features properly sized in proportion to the waste gas stream and thereby values approaching or less than 0.05 kg (0.10 lbs) steam is used per pound of propane waste gas. 
     
     
         17 . The process of  claim 14  wherein all of said steam is injected internally to said waste gas before exposure to surrounding atmospheric air. 
     
     
         18 . The process of  claim 14  wherein most of said steam is injected internally to waste gas before exposure to surrounding atmospheric air and some of said steam is injected externally to separate combusting stream from hub metal. 
     
     
         19 . The process of  claim 17  wherein curved transition pieces between flare gas cylinder and said waste gas conduits improve flow distribution exiting said waste gas conduits and reduce pressure drop through flare gas system.