Method and system for lancing gas into an environment with variable entrainment of non-lanced gas

Abstract

A system and method are disclosed for lancing gas into an environment, such as a furnace, wherein an inner conduit is in communication with a gas supply and adapted to transport a gas at a first mass flow rate, and an outer conduit is in communication with a gas supply and adapted to transport a gas at a second mass flow rate. The first mass flow rate is greater than the second mass flow rate, preferably at least two times greater. The distal end of the inner conduit is preferably recessed back at a distance from the distal end of the outer conduit.

1 . A system for lancing gas into an environment, comprising: 
 an inner conduit and an outer conduit, said inner conduit being in communication with a gas supply and adapted to transport a gas at a first mass flow rate, said outer conduit being in communication with a gas supply and adapted to transport a gas at a second mass flow rate, the first mass flow rate being greater than the second mass flow rate.    
   
   
       2 . The system of  claim 1  wherein the first mass flow rate is at least two times greater than the second mass flow rate.  
   
   
       3 . The system of  claim 1  wherein the first mass flow rate is at least three times greater than the second mass flow rate.  
   
   
       4 . The system of  claim 1  wherein the first mass flow rate is at least 10 tons per day and the second mass flow rate is at least 5 tons per day.  
   
   
       5 . The system of  claim 1  wherein the first mass flow rate is at least 50 tons per day and the second mass flow rate is at least 25 tons per day.  
   
   
       6 . The system of  claim 1  wherein the first mass flow rate is at least 100 tons per day and the second mass flow rate is at least 50 tons per day.  
   
   
       7 . The system of  claim 1  wherein the first mass flow rate is at least 150 tons per day and the second mass flow rate is at least 75 tons per day.  
   
   
       8 . The system of  claim 1  wherein the distal end of the inner conduit is recessed a distance from the distal end of the outer conduit.  
   
   
       9 . The system of  claim 8  wherein the inner diameter of the distal end of the inner conduit ranges from about 1 to about 16 cm, and the inner diameter of the distal end of the outer conduit ranges from about 2 to about 31 cm.  
   
   
       10 . The system of  claim 8  wherein the inner diameter of the distal end of the inner conduit ranges from about 2 to about 10 cm, and the inner diameter of the distal end of the outer conduit ranges from about 5 to about 21 cm.  
   
   
       11 . The system of  claim 8  wherein the recess distance ranges from about 0.5 to about 6 times the inner diameter of distal end of the outer conduit.  
   
   
       12 . The system of  claim 8  wherein the recess distance ranges from about 1 to about 4 times the inner diameter of distal end of the outer conduit.  
   
   
       13 . The system of  claim 8  wherein the recess distance ranges from about 1 to about 186 cm.  
   
   
       14 . The system of  claim 8  wherein the recess distance ranges from 5 to about 84 cm.  
   
   
       15 . The system of  claim 1  wherein the gas transported though the inner conduit is supplied at a pressure ranging from about 500 Pa to about 700,000 Pa and the gas transported through the outer conduit is supplied at a pressure ranging from about 70 Pa to about 150,000 Pa.  
   
   
       16 . The system of  claim 1  wherein the gas transported through the inner conduit is supplied at a pressure ranging from about 650 Pa to about 450,000 Pa and the gas transported through the outer conduit is supplied at a pressure ranging from about 150 Pa to about 75,000 Pa.  
   
   
       17 . The system of  claim 1  wherein the gas transported through the inner conduit is oxygen and the gas transported through the outer conduit is oxygen.  
   
   
       18 . The system of  claim 1  wherein the gas transported through the inner conduit is oxygen and the gas transported through the outer conduit is air.  
   
   
       19 . The system of  claim 1  wherein the gas transported through the inner conduit is oxygen and the gas transported through the outer conduit is nitrogen.  
   
   
       20 . The system of  claim 1  wherein the gas transported through the inner conduit is oxygen and the gas transported through the outer conduit is carbon dioxide.  
   
   
       21 . The system of  claim 1  wherein the gas transported through the inner conduit is oxygen and the gas transported through the outer conduit is flue gas.  
   
   
       22 . The system of  claim 1  wherein the gas transported through the inner conduit is oxygen and the gas transported through the outer conduit is argon.  
   
   
       23 . The system of  claim 1  wherein the gas transported through the inner conduit is oxygen and the gas transported through the outer conduit is steam.  
   
   
       24 . The system of  claim 1  wherein the gas supply for the gas transported through the inner conduit is the same as the gas supply for the gas transported through the outer conduit.  
   
   
       25 . The system of  claim 1  wherein the gas supply for the gas transported through the inner conduit is different from the gas supply for the gas transported through the outer conduit.  
   
   
       26 . A method of lancing gas into an environment, comprising the steps of: 
 injecting a gas at a first mass flow rate through an inner conduit; and    injecting a gas at a second mass flow rate through an outer conduit, the inner and outer conduits being concentric, and the first mass flow rate being greater than the second mass flow rate.    
   
   
       27 . The method of  claim 26  wherein the first mass flow rate is at least two times greater than the second mass flow rate.  
   
   
       28 . The method of  claim 26  wherein the first mass flow rate is at least three times greater than the second mass flow rate.  
   
   
       29 . The method of  claim 26  wherein the first mass flow rate is at least 10 tons per day and the second mass flow rate is at least 5 tons per day.  
   
   
       30 . The method of  claim 26  wherein the first mass flow rate is at least 50 tons per day and the second mass flow rate is at least 25 tons per day.  
   
   
       31 . The method of  claim 26  wherein the first mass flow rate is at least 100 tons per day and the second mass flow rate is at least 50 tons per day.  
   
   
       32 . The method of  claim 26  wherein the first mass flow rate is at least 150 tons per day and the second mass flow rate is at least 75 tons per day.  
   
   
       33 . The method of  claim 26  wherein the distal end of the inner conduit is recessed a distance from the distal end of the outer conduit.  
   
   
       34 . The method of  claim 33  wherein the inner diameter of the distal end of the inner conduit ranges from about 1 to about 16 cm, and the inner diameter of the distal end of the outer conduit ranges from about 2 to about 31 cm.  
   
   
       35 . The method of  claim 33  wherein the inner diameter of the distal end of the inner conduit ranges from about 2 to about 10 cm, and the inner diameter of the distal end of the outer conduit ranges from about 5 to about 21 cm.  
   
   
       36 . The method of  claim 33  wherein the recess distance ranges from about 0.5 to about 6 times the inner diameter of distal end of the outer conduit.  
   
   
       37 . The method of  claim 33  wherein the recess distance ranges from about 1 to about 4 times the inner diameter of distal end of the outer conduit.  
   
   
       38 . The method of  claim 33  wherein the recess distance ranges from about 1 to about 186 cm.  
   
   
       39 . The method of  claim 33  wherein the recess distance ranges from 5 to about 84 cm.  
   
   
       40 . The method of  claim 26  wherein the gas transported through the inner conduit is supplied at a pressure ranging from about 500 Pa to about 700,000 Pa and the gas transported through the outer conduit is supplied at a pressure ranging from about 70 Pa to about 150,000 Pa.  
   
   
       41 . The method of  claim 26  wherein the gas transported through the inner conduit is supplied at a pressure ranging from about 650 Pa to about 450,000 Pa and the gas transported through the outer conduit is supplied at a pressure ranging from about 150 Pa to about 75,000 Pa.  
   
   
       42 . The method of  claim 26  wherein the gas transported through the inner conduit is oxygen and the gas transported through the outer conduit is oxygen.  
   
   
       43 . The method of  claim 26  wherein the gas transported through the inner conduit is oxygen and the gas transported through the outer conduit is air.  
   
   
       44 . The method of  claim 26  wherein the gas transported through the inner conduit is oxygen and the gas transported through the outer conduit is nitrogen.  
   
   
       45 . The method of  claim 26  wherein the gas transported through the inner conduit is oxygen and the gas transported through the outer conduit is carbon dioxide.  
   
   
       46 . The method of  claim 26  wherein the gas transported through the inner conduit is oxygen and the gas transported through the outer conduit is flue gas.  
   
   
       47 . The method of  claim 26  wherein the gas transported through the inner conduit is oxygen and the gas transported through the outer conduit is argon.  
   
   
       48 . The method of  claim 26  wherein the gas transported through the inner conduit is oxygen and the gas transported through the outer conduit is steam.