Air flare apparatus and method

Abstract

A flare apparatus for discharging and burning flare gas in the atmosphere is provided. The flare tip includes a flare gas conduit having a flare gas discharge opening and a combustion air conduit having a combustion air discharge opening. All of the flare gas to be flared is discharged through the flare gas discharge opening into a unified column of air discharged through the combustion air discharge opening. The flare gas discharge opening and the combustion air discharge opening are positioned with respect to one another such that flare gas discharged from the flare gas discharge opening is discharged inwardly into combustion air that is discharged from the combustion air discharge opening and admixed therewith. Essentially all of the discharged flare gas is admixed with discharged combustion air or external atmospheric air outside of the flare apparatus thereby preventing internal burning. A method of flaring a mixture of flare gas and combustion air is also provided.

1 . A flare tip for use in association with a flare apparatus for discharging and burning flare gas in the atmosphere comprising:
 a flare gas conduit including a first end, a second end and a side wall connecting said first end to said second end, wherein said flare gas conduit is adapted to be fluidly connected to a source of flare gas and said second end of said flare gas conduit defines a flare gas discharge opening, said flare gas conduit and said flare gas discharge opening being of a size sufficient to allow all of the flare gas that is to be discharged and burned by said flare apparatus to be discharged through said flare gas discharge opening; and   a combustion air conduit associated with said flare gas conduit, said combustion air conduit including a first end, a second end and a side wall connecting said first end to said second end, wherein said combustion air conduit is adapted to be fluidly connected to a source of combustion air, and said second end of said combustion air conduit defines a combustion air discharge opening, said combustion air conduit having a structure that causes a unified column of combustion air to be discharged through said combustion air discharge opening,   said flare gas discharge opening and said combustion air discharge opening being positioned with respect to one another such that essentially all of the flare gas to be discharged and burned by said flare apparatus can be discharged through said flare gas discharge opening inwardly into the column of combustion air discharged from said combustion air discharge opening and such that essentially all of the discharged flare gas can be admixed with discharged combustion air or external atmospheric air outside of said combustion air conduit and said flare gas conduit.   
     
     
         2 . The flare tip of  claim 1 , wherein said combustion air conduit is positioned at least partially within said flare gas conduit, and wherein said flare gas discharge opening and said combustion air discharge opening are positioned with respect to one another such that essentially all of the flare gas to be discharged and burned by said flare apparatus can be discharged through said flare gas discharge opening around and inwardly into the column of combustion air discharged from said combustion air discharge opening. 
     
     
         3 . The flare tip of  claim 2 , wherein the height of said combustion air conduit is equal to, greater than, or less than the height of said flare gas conduit, and wherein if the height of said combustion air conduit is less than the height of said flare gas conduit, the ratio of the difference between the heights of said combustion air conduit and said flare gas conduit to the hydraulic diameter of said combustion air conduit is no greater than 0.05. 
     
     
         4 . The flare tip of  claim 2 , wherein the height of said combustion air conduit is equal to, greater than, or less than the height of said flare gas conduit, and wherein in the event that the height of said combustion air conduit is less than the height of said flare gas conduit, the ratio of the difference between the heights of said combustion air conduit and said flare gas conduit to the hydraulic diameter of said combustion air conduit is no greater than 0.02. 
     
     
         5 . The flare tip of  claim 2 , wherein the height of said combustion air conduit is equal to or greater than the height of said flare gas conduit. 
     
     
         6 . The flare tip of  claim 5 , wherein the height of said combustion air conduit is greater than the height of said flare gas conduit, and wherein the ratio of the difference between the heights of said combustion air conduit and said flare gas conduit to the hydraulic diameter of said combustion air conduit is approximately 0.01. 
     
     
         7 . The flare tip of  claim 1 , wherein said side wall of said flare gas conduit includes a portion adjacent to said flare gas discharge opening that tapers inwardly toward the vertical central axis of said combustion air conduit. 
     
     
         8 . The flare tip of  claim 7 , wherein said portion of said side wall of said flare gas conduit adjacent to said flare gas discharge opening tapers inwardly toward the vertical central axis of said combustion air conduit at an angle in the range of from about 10° to about 90°. 
     
     
         9 . The flare tip of  claim 8 , wherein said portion of said side wall of said flare gas conduit adjacent to said flare gas discharge opening tapers inwardly toward the vertical central axis of said combustion air conduit at an angle in the range of from about 25° to about 45°. 
     
     
         10 . The flare tip of  claim 9 , wherein said portion of said side wall of said flare gas conduit adjacent to said flare gas discharge opening tapers inwardly toward the vertical central axis of said combustion air conduit at an angle of about 35°. 
     
     
         11 . The flare tip of  claim 1 , wherein said side wall of said combustion air conduit includes a portion adjacent to said combustion air discharge opening that tapers inwardly toward the vertical central axis of said combustion air conduit. 
     
     
         12 . The flare tip of  claim 1 , wherein said flare gas conduit and said combustion air conduit each have circular cross-sections, and said combustion air conduit is at least partially concentrically disposed within said flare gas conduit. 
     
     
         13 . The flare tip of  claim 12 , wherein the height of said combustion air conduit is equal to, greater than, or less than the height of said flare gas conduit, and wherein if the height of said combustion air conduit is less than the height of said flare gas conduit, the ratio of the difference between the heights of said combustion air conduit and said flare gas conduit to the diameter of said combustion air conduit is no greater than 0.05. 
     
     
         14 . The flare tip of  claim 12 , wherein said flare gas conduit further comprises:
 an inlet adapted to be fluidly connected to a source of flare gas; and   a flow distribution member attached within said flare gas conduit.   
     
     
         15 . The flare tip of  claim 14 , wherein said flow distribution member is an annular plate disposed within said flare gas conduit. 
     
     
         16 . The flare tip of  claim 12 , wherein said flare gas conduit includes at least one inlet adapted to be fluidly connected to a source of flare gas and to inject flare gas into said flare gas conduit at an angle with respect to the vertical central axis of said flare gas conduit. 
     
     
         17 . The flare tip of  claim 16 , wherein said flare gas conduit includes at least two inlets, each inlet adapted to be fluidly connected to a source of flare gas and to inject flare gas into said flare gas conduit at an angle with respect to the vertical central axis of said flare gas conduit. 
     
     
         18 . A flare tip for use in association with a flare apparatus for discharging and burning flare gas in the atmosphere comprising:
 a flare gas conduit including a first end, a second end and a side wall connecting said first end to said second end, wherein said flare gas conduit is adapted to be fluidly connected to a source of flare gas and said second end of said flare gas conduit defines a flare gas discharge opening, said flare gas conduit and said flare gas discharge opening being of a size sufficient to allow all of the flare gas that is to be discharged and burned by said flare apparatus to be discharged through said flare gas discharge opening; and   a combustion air conduit positioned at least partially within said flare gas conduit, said combustion air conduit including a first end, a second end and a side wall connecting said first end to said second end, wherein said combustion air conduit is adapted to be fluidly connected to a source of combustion air, and said second end of said combustion air conduit defines a combustion air discharge opening, said combustion air conduit having a structure that causes a unified column of combustion air to be discharged through said combustion air discharge opening,   said flare gas discharge opening and said combustion air discharge opening being positioned with respect to one another such that essentially all of the flare gas to be discharged and burned by said flare apparatus can be discharged through said flare gas discharge opening around and inwardly into the column of combustion air discharged from said combustion air discharge opening and such that essentially all of the discharged flare gas can be admixed with discharged combustion air or external atmospheric air outside of said combustion air conduit and said flare gas conduit.   
     
     
         19 . The flare tip of  claim 18 , wherein the height of said combustion air conduit is equal to, greater than, or less than the height of said flare gas conduit, and wherein if the height of said combustion air conduit is less than the height of said flare gas conduit, the ratio of the difference between the heights of said combustion air conduit and said flare gas conduit to the hydraulic diameter of said combustion air conduit is no greater than 0.05. 
     
     
         20 . The flare tip of  claim 18 , wherein the height of said combustion air conduit is equal to, greater than, or less than the height of said flare gas conduit, and wherein in the event that the height of said combustion air conduit is less than the height of said flare gas conduit, the ratio of the difference between the heights of said combustion air conduit and said flare gas conduit to the hydraulic diameter of said combustion air conduit is no greater than 0.02. 
     
     
         21 . The flare tip of  claim 20 , wherein the height of said combustion air conduit is equal to or greater than the height of said flare gas conduit. 
     
     
         22 . The flare tip of  claim 21 , wherein the height of said combustion air conduit is greater than the height of said flare gas conduit, and wherein the ratio of the difference between the heights of said combustion air conduit and said flare gas conduit to the hydraulic diameter of said combustion air conduit is approximately 0.01. 
     
     
         23 . The flare tip of  claim 18 , wherein said side wall of said flare gas conduit includes a portion adjacent to said flare gas discharge opening that tapers inwardly toward the vertical central axis of said combustion air conduit. 
     
     
         24 . The flare tip of  claim 23 , wherein said portion of said side wall of said flare gas conduit adjacent to said flare gas discharge opening tapers inwardly toward the vertical central axis of said combustion air conduit at an angle in the range of from about 10° to about 90°. 
     
     
         25 . The flare tip of  claim 24 , wherein said portion of said side wall of said flare gas conduit adjacent to said flare gas discharge opening tapers inwardly toward the vertical central axis of said combustion air conduit at an angle in the range of from about 25° to about 45°. 
     
     
         26 . The flare tip of  claim 25 , wherein said portion of said side wall of said flare gas conduit adjacent to said flare gas discharge opening tapers inwardly toward the vertical central axis of said combustion air conduit at an angle of about 35°. 
     
     
         27 . The flare tip of  claim 18 , wherein said side wall of said combustion air conduit includes a portion adjacent to said combustion air discharge opening that tapers inwardly toward the vertical central axis of said combustion air conduit. 
     
     
         28 . The flare tip of  claim 18 , wherein said flare gas conduit and said combustion air conduit each have circular cross-sections, and said combustion air conduit is at least partially concentrically disposed within said flare gas conduit. 
     
     
         29 . The flare tip of  claim 28 , wherein the height of said combustion air conduit is equal to, greater than, or less than the height of said flare gas conduit, and wherein if the height of said combustion air conduit is less than the height of said flare gas conduit, the ratio of the difference between the heights of said combustion air conduit and said flare gas conduit to the diameter of said combustion air conduit is no greater than 0.05. 
     
     
         30 . The flare tip of  claim 28 , wherein said flare gas conduit further comprises:
 an inlet adapted to be fluidly connected to a source of flare gas; and   a flow distribution member attached within said flare gas conduit.   
     
     
         31 . The flare tip of  claim 30 , wherein said flow distribution member is an annular plate disposed within said flare gas conduit. 
     
     
         32 . The flare tip of  claim 28 , wherein said flare gas conduit includes at least one inlet adapted to be fluidly connected to a source of flare gas and to inject flare gas into said flare gas conduit at an angle with respect to the vertical central axis of said flare gas conduit. 
     
     
         33 . The flare tip of  claim 32 , wherein said flare gas conduit includes at least two inlets, each inlet adapted to be fluidly connected to a source of flare gas and to inject flare gas into said flare gas conduit at an angle with respect to the vertical central axis of said flare gas conduit. 
     
     
         34 . A method of flaring a mixture of flare gas and combustion air in a flare apparatus without pre-mixing a significant portion of the flare gas with the combustion air within the flare apparatus prior to discharging the flare gas and combustion air from the flare apparatus, comprising:
 (a) discharging a unified column of combustion air into the atmosphere from the flare apparatus;   (b) discharging essentially all of the flare gas to be flared by the flare apparatus into the atmosphere from the flare apparatus and inwardly into the discharged column of combustion air such that essentially all of the discharged flare gas is admixed with discharged combustion air or external atmospheric air outside of the flare apparatus; and   (c) igniting the mixture of discharged flare gas, discharged combustion air and external atmospheric air.   
     
     
         35 . The method of  claim 34 , wherein all of the flare gas to be flared by the flare apparatus is discharged into the atmosphere from the flare apparatus and inwardly into the discharged column of combustion air. 
     
     
         36 . The method of  claim 34 , wherein the combustion air is discharged into the atmosphere from the flare apparatus at a radial velocity less than the radial velocity at which the flare gas is discharged into the atmosphere from said flare apparatus. 
     
     
         37 . The method of  claim 36 , wherein the combustion air is discharged into the atmosphere from the flare apparatus at an axial velocity of at least 50 feet per second. 
     
     
         38 . The method of  claim 37 , wherein the combustion air is discharged into the atmosphere from the flare apparatus at an axial velocity in the range of from about 50 feet per second to about 200 feet per second. 
     
     
         39 . The method of  claim 38 , wherein the combustion air is discharged into the atmosphere from the flare apparatus at an axial velocity in the range of from about 120 feet per second to about 150 feet per second. 
     
     
         40 . The method of  claim 39 , wherein the combustion air is discharged into the atmosphere from the flare apparatus at an axial velocity of about 150 feet per second. 
     
     
         41 . The method of  claim 34 , wherein essentially all of the flare gas to be flared by the flare apparatus is discharged into the atmosphere from the flare apparatus around the discharged column of combustion air and inwardly into the discharged column of combustion air. 
     
     
         42 . The method of  claim 41 , wherein essentially all of the flare gas to be flared by the flare apparatus is discharged into the atmosphere from the flare apparatus inwardly into the discharged combustion air at an angle in the range of from about 10° to about 90°. 
     
     
         43 . The method of  claim 42 , wherein essentially all of the flare gas to be flared by the flare apparatus is discharged into the atmosphere from the flare apparatus inwardly into the discharged combustion air at an angle in the range of from about 25° to about 45°. 
     
     
         44 . The method of  claim 43 , wherein essentially all of the flare gas to be flared by the flare apparatus is discharged into the atmosphere from the flare apparatus inwardly into the discharged combustion air at an angle of about 35°. 
     
     
         45 . The method of claim  413  wherein all of the flare gas to be flared by the flare apparatus is discharged into the atmosphere from the flare apparatus around the discharged column of combustion air and inwardly into the discharged column of combustion air. 
     
     
         46 . The method of  claim 34 , further comprising reducing the static pressure of a portion of the admixture of discharged flare gas, discharged combustion air and/or external atmospheric air adjacent to the flare apparatus. 
     
     
         47 . The method of  claim 46 , wherein the static pressure of a portion of the admixture of discharged flare gas, discharged combustion air and/or external atmospheric air adjacent to the flare apparatus is reduced by creating a low pressure zone in the area of said combustion air discharge opening. 
     
     
         48 . The method of  claim 47 , wherein a low pressure zone is created adjacent to the flare apparatus by causing the flare gas to be discharged from the flare apparatus in a swirling annular pattern around the discharged combustion air. 
     
     
         49 . The method of  claim 34  further comprising blowing combustion air into the flare apparatus.