Enclosed flare stack and method of flaring waste gas

Abstract

An enclosed flare stack having expanded air entries for flaring waste gas. The flare stack includes an enclosure assembly having a bottom portion with expanded air entries and an upper portion through which the flared waste gas escapes. The enlarged air entries at the bottom end of the stack to reduce entry pressure loss and to increase entrained air flow when flaring waste gas. The enclosed flare stack and method of flaring waste gas also greatly reduce the height of the stack enclosure without greatly increasing the size of the flare windows.

1 . An enclosed flare stack having a flow path for flaring waste gas, said stack comprising:
 an enclosure assembly having a bottom portion with at least one expanded air entry and an upper portion through which said flared waste gas escapes, said expanded air entry comprising at least one upper panel having a predetermined angle with respect to said upper portion of the enclosure assembly; and   a flare window adjacent to said expanded air entry of said enclosure assembly.   
     
     
         2 . The enclosed flare stack of  claim 1  further comprising a radiation fence that completely surrounds and circumnavigates said flare stack. 
     
     
         3 . The enclosed flare stack of  claim 1  further comprising a plurality of flare manifold assemblies in fluid communication with said flare windows. 
     
     
         4 . The enclosed flare stack of  claim 3  said manifold assemblies completely or substantially surround said flow path through said flare stack. 
     
     
         5 . The enclosed flare stack of  claim 1  wherein said predetermined angle between said upper panel of said expanded air entry and said upper portion of said enclosure assembly ranges between about 110 and about 160 degrees. 
     
     
         6 . The enclosed flare stack of  claim 5  wherein said predetermined angle is about 135 degrees. 
     
     
         7 . The enclosed flare stack of  claim 1  wherein said predetermined angle between said upper panel of said expanded air entry and said upper portion of said enclosure assembly further comprises a generally smooth radius, downwardly sloping angle. 
     
     
         8 . The enclosed flare stack of  claim 1  wherein said predetermined angle between said upper panel of said expanded air entry and said upper portion of said enclosure assembly further comprises a concave angle toward said flow path through said enclosed flare stack. 
     
     
         9 . The enclosed flare stack of  claim 1  wherein said expanded air entry continuously radially surrounds and enlarges said bottom portion of said enclosure assembly. 
     
     
         10 . The enclosed flare stack of  claim 1  wherein said expanded air entry is a plurality of expanded air entries. 
     
     
         11 . The enclosed flare stack of  claim 10  wherein said predetermined angles between said upper panels of said expanded air entries and said upper portion of said enclosure assembly range between about 110 and about 160 degrees, are generally smooth radius, downwardly sloping angles, are concave angles toward said flow path through said enclosed flare stack or are a combination thereof. 
     
     
         12 . The enclosed flare stack of  claim 11  wherein said predetermined angle is about 135 degrees. 
     
     
         13 . The enclosed flare stack of  claim 10  wherein said expanded air entries further side panels, side windows or a combination thereof. 
     
     
         14 . The enclosed flare stack of  claim 10  wherein said expanded air entries are spaced from and generally parallel to each other. 
     
     
         15 . The enclosed flare stack of  claim 10  wherein said air entries are contiguous with each other. 
     
     
         16 . A method of flaring waste gas using an enclosed flare stack, said method comprising the steps of:
 flowing a waste gas through said enclosed flare stack;   entraining air through at least one flare windows in said flare stack;   entraining additional air through at least one expanded air entry in said flare stack, said expanded air entry comprising at least one upper panel having a predetermined angle with respect to an upper portion of said flare stack; and   flaring said waste gas.   
     
     
         17 . The method of flaring waste gas of  claim 16  wherein said expanded air entry is a plurality of expanded air entries. 
     
     
         18 . The method of flaring waste gas of  claim 17  wherein said predetermined angles between said upper panels of said expanded air entries and said upper portion of said flare stack ranges between about 110 and about 160 degrees, are generally smooth radius, downwardly sloping angles, are concave angles toward said flow path through said enclosed flare stack or are a combination thereof. 
     
     
         19 . The method of flaring waste gas of  claim 18  wherein said predetermined angle is about 135 degrees. 
     
     
         20 . The method of flaring waste gas of  claim 17  wherein said expanded air entries further side panels, side windows or a combination thereof.