Gas recuperative flameless thermal oxidizer

Abstract

The invention provides a gas recuperative flameless thermal oxidizer. The oxidizer includes a matrix bed and at least one feed passage extending at least partially within the matrix bed. The feed passage has an inlet configured to receive combustible vapor or an air-combustible vapor mixture and an outlet configured to deliver the combustible vapor or the air-combustible vapor mixture into the matrix bed. The feed passage has a cross-sectional area and a length within the matrix bed, wherein a ratio of the length (ft) to the cross-sectional area (in 2 ) is at least about 0.5:1.

1 . A gas recuperative flameless thermal oxidizer comprising: 
 a matrix bed; and    at least one feed passage extending at least partially within said matrix bed, said feed passage having an inlet configured to receive combustible vapor or an air-combustible vapor mixture and an outlet configured to deliver the combustible vapor or the air-combustible vapor mixture into said matrix bed, said at least one feed passage having a cross-sectional area and a length within the matrix bed, wherein a ratio of said length (ft) to said cross-sectional area (in 2 ) is at least about 0.5:1.    
   
   
       2 . The gas recuperative flameless thermal oxidizer of  claim 1 , wherein said ratio of said length (ft) to said cross-sectional area (in 2 ) is from about 0.5:1 to about 2.5:1.  
   
   
       3 . The gas recuperative flameless thermal oxidizer of  claim 1 , wherein said cross-sectional area of said at least one feed passage is about 29 in 2  or less.  
   
   
       4 . The gas recuperative flameless thermal oxidizer of  claim 1 , wherein a cross sectional area defined by the at least one feed passage, taken together, is between about 10% and 50% relative to a cross sectional area of the matrix bed.  
   
   
       5 . The gas recuperative flameless thermal oxidizer of  claim 1 , wherein a cross sectional area defined by the at least one feed passage, taken together, is between about 20% and 30% relative to a cross sectional area of the matrix bed.  
   
   
       6 . The gas recuperative flameless thermal oxidizer of  claim 1 , wherein said length of said feed passage is about 2 ft or more.  
   
   
       7 . The gas recuperative flameless thermal oxidizer of  claim 1  comprising a plurality of feed passages, said feed passages being positioned at a pitch of between about one and eight inches.  
   
   
       8 . The gas recuperative flameless thermal oxidizer of  claim 7 , wherein the pitch is between about five and eight inches.  
   
   
       9 . A method of oxidizing combustible vapor in a gas recuperative flameless thermal oxidizer, said method comprising the steps of: 
 delivering combustible vapor or an air-combustible vapor mixture below the lower flammability limit into an inlet of a feed passage and through an outlet of the feed passage to a matrix bed;    maintaining a length within the matrix bed of the feed passage such that a ratio of the length (ft) to the cross-sectional area (in 2 ) of the feed passage is at least about 0.5:1.    
   
   
       10 . A gas recuperative flameless thermal oxidizer comprising: 
 a matrix bed; and    at least one feed passage extending at least partially within said matrix bed, said feed passage having an outlet configured to deliver combustible vapor or an air-combustible vapor mixture into said matrix bed; and    at least one separate fuel inlet configured to introduce fuel into said matrix bed, said fuel inlet being positioned downstream of said outlet of said feed passage.    
   
   
       11 . The gas recuperative flameless thermal oxidizer of  claim 10 , wherein the fuel inlet is positioned proximal to the outlet of the feed passage.  
   
   
       12 . The gas recuperative flameless thermal oxidizer of  claim 10 , wherein the fuel inlet is positioned co-linear with the outlet of the feed passage.  
   
   
       13 . A method of oxidizing combustible vapor in a gas recuperative flameless thermal oxidizer, said method comprising the steps of: 
 delivering combustible vapor or an air-combustible vapor mixture below the lower flammability limit into a matrix bed through an outlet of a feed passage; and    introducing fuel into the matrix bed through a separate fuel inlet at a position downstream of the outlet of the feed passage.    
   
   
       14 . The method of  claim 13 , wherein said introducing step comprises introducing fuel at a position proximal to the outlet of the feed passage.  
   
   
       15 . The method of  claim 13 , wherein said introducing step comprises introducing fuel at a position co-linear with the outlet of the feed passage.  
   
   
       16 . The method of  claim 13 , wherein the step of introducing fuel comprises introducing natural gas.  
   
   
       17 . The method of  claim 13 , wherein the step of introducing fuel comprises introducing No. 2 fuel oil.  
   
   
       18 . A gas recuperative flameless thermal oxidizer comprising: 
 a matrix bed; and    at least one feed passage extending at least partially within said matrix bed, said feed passage having an inlet configured to receive combustible vapor or an air-combustible vapor mixture and an outlet configured to deliver the combustible vapor or the air-combustible vapor mixture into said matrix bed;    said feed passage defining an interior extending within the matrix, said interior being substantially devoid of matrix.    
   
   
       19 . A method of oxidizing combustible vapor in a gas recuperative flameless thermal oxidizer, said method comprising the steps of: 
 delivering combustible vapor or an air-combustible vapor mixture below the lower flammability limit into an inlet of a feed passage and through an outlet of the feed passage to a matrix bed;    maintaining an interior of the feed passage extending within the matrix of the feed passage substantially devoid of matrix.    
   
   
       20 . A gas recuperative flameless thermal oxidizer comprising: 
 a matrix bed positioned to exhaust gaseous oxidation products along an exhaust path; and    at least one feed passage extending at least partially within said matrix bed, said feed passage having an inlet configured to receive combustible vapor and an outlet configured to deliver the combustible vapor into said matrix bed, said feed passage defining a combustible vapor path extending within the matrix in a direction substantially opposite that of said exhaust path of said matrix bed;    wherein said combustible vapor path of said feed passage and said exhaust path of said matrix bed are configured to provide a ratio between the velocity of combustible vapor in said combustible vapor path and the velocity of exhaust in said exhaust path between about 0.5:1 and 2.5:1.    
   
   
       21 . The gas recuperative flameless thermal oxidizer of  claim 20 , wherein the ratio between the velocity of combustible vapor in said combustible vapor path and the velocity of exhaust in said exhaust path is between about 0.9:1 and about 1.1:1.  
   
   
       22 . A method of oxidizing combustible vapor in a gas recuperative flameless thermal oxidizer, said method comprising the steps of: 
 delivering combustible vapor below the lower flammability limit into an inlet of a feed passage, along a combustible vapor path, and through an outlet of the feed passage to a matrix bed;    exhausting gaseous oxidation products along an exhaust path in the matrix bed in a direction that is substantially opposite that of the combustible vapor path of the feed passage; and    maintaining a ratio between the velocity of combustible vapor in the combustible vapor path and the velocity of exhaust in the exhaust path between about 0.5:1 and 2.5:1.    
   
   
       23 . The method of  claim 22 , wherein said maintaining step comprises maintaining the ratio between the velocity of combustible vapor in said combustible vapor path and the velocity of exhaust in said exhaust path between about 0.9:1 and about 1.1:1.  
   
   
       24 . A gas recuperative flameless thermal oxidizer comprising: 
 an enclosure;    a matrix bed contained within said enclosure;    feed tubes extending into said enclosure and at least partially within said matrix bed, said feed tubes being positioned to deliver combustible vapor or an air-combustible vapor mixture into said matrix bed; and    a matrix bed support mounted within said enclosure, said matrix bed support having a surface substantially impervious to the flow of exhaust supporting said matrix bed, said matrix bed support defining apertures therein each sized to receive a feed tube and provide exhaust passages proximal to said apertures.    
   
   
       25 . In a gas recuperative flameless thermal oxidizer having an enclosure, a matrix bed contained within the enclosure, and feed tubes extending into the enclosure and at least partially within the matrix bed, a method of oxidizing combustible vapor comprising the steps of: 
 delivering combustible vapor or an air-combustible vapor mixture below the lower flammability limit into the matrix bed through the feed tubes;    directing substantially all gaseous oxidation products in the matrix bed through apertures in a matrix bed support adjatent the feed tubes; and    exhausting gaseous oxidation products from the gas recuperative flameless thermal oxidizer through an outlet in the enclosure.    
   
   
       26 . A gas recuperative flameless thermal oxidizer comprising: 
 an enclosure extending between opposed end portions;    a matrix bed contained within said enclosure;    feed tubes extending into said enclosure and at least partially within said matrix bed, said feed tubes being positioned to deliver combustible vapor or an air-combustible vapor mixture into said matrix bed; and    means for adjusting the distance between said opposed end portions of said enclosure to increase or decrease the size of the matrix bed.    
   
   
       27 . The gas recuperative flameless thermal oxidizer of  claim 26 , said adjusting means comprising at least one wall section configured to be added to or removed from said enclosure between said opposed end portions of said enclosure.  
   
   
       28 . The gas recuperative flameless thermal oxidizer of  claim 27 , said wall section having a surface configured to be coupled to another wall section or to one of said opposed end portions of said enclosure.  
   
   
       29 . The gas recuperative flameless thermal oxidizer of  claim 26 , said adjusting means comprising at least one extension section configured to be added to or removed from said feed tubes between said opposed end portions of said enclosure.  
   
   
       30 . The gas recuperative flameless thermal oxidizer of  claim 29 , said extension section having a surface configured to be coupled to another extension section or to another portion of said feed tubes.  
   
   
       31 . The gas recuperative flameless thermal oxidizer of  claim 1 , wherein said ratio of said length (ft) to said cross-sectional area (in 2 ) is at least about 1.2:1.  
   
   
       32 . The gas recuperative flameless thermal oxidizer of  claim 31 , wherein said ratio of said length (ft) to said cross-sectional area (in 2 ) is from about 1.2:1 to about 2.1:1.  
   
   
       33 . The gas recuperative flameless thermal oxidizer of  claim 1 , wherein said ratio of said length (ft) to said cross-sectional area (in 2 ) is about 1.6:1.