Dynamic control of lance utilizing co-flow fluidic techniques

Abstract

A jet of gas injected from a lance is fluidically deviated with a gas flowing in either the same or opposite direction as the jet of gas. The gas used to fluidically deviate the jet is the same as or different from the gas in the jet.

1 . A method of injecting a jet of a gas into an interior of a reaction space containing a liquid or solid reactant, said method comprising the steps of:
 providing a lance comprising a main body having a primary conduit and a secondary conduit formed therein and upstream and downstream ends, each of the primary and secondary conduits extending between a respective inlet and a respective outlet, the outlets being disposed at the downstream end, an outlet of the secondary conduit being disposed at a location adjacent the primary conduit outlet;   injecting a jet of a first gas from the outlet of the primary conduit and into the reaction space; and   injecting a second gas from the outlet of the secondary conduit to create a co-flow of the second gas adjacent to a peripheral region of the jet such that the jet is deviated towards the co-flow of second gas, wherein the first and second gases are the same or different.   
     
     
         2 . The method of  claim 1 , wherein the jet has a velocity with a Mach number in a range of from 0.3 to 5.0. 
     
     
         3 . The method of  claim 1 , wherein the first gas is oxygen-enriched air. 
     
     
         4 . The method of  claim 1 , wherein the first gas is oxygen. 
     
     
         5 . The method of  claim 1 , wherein the first gas is the same as the second gas and the first and second gases are at different pressures upstream of the lance. 
     
     
         6 . The method of  claim 1 , wherein:
 the primary conduit extends along an axis;   the jet is deviated by an angle θ with respect to the axis; and   θ is in the range of 0°<θ≦45°.   
     
     
         7 . The method of  claim 1 , further comprising the step of discontinuing said injection of the second gas from the secondary conduit wherein the jet is no longer deviated towards the co-flow. 
     
     
         8 . The method of  claim 7 , wherein said steps of applying and discontinuing are alternated such that the jet is swept along an area described by an angle θ in the range of 0°<θ≦45°. 
     
     
         9 . The method of  claim 1 , wherein:
 the lance has a plurality of secondary conduits each one of which extends between a respective inlet and a respective outlet, each of the secondary conduit outlets being disposed at the downstream end; and   injection of the second gas is alternated between the plurality of secondary conduits to provide an alternating plurality of co-flows and to alternatingly deviate the jet towards different ones of the plurality of co-flows.   
     
     
         10 . The method of  claim 9 , wherein alternating injection of the second gas between two of the secondary conduits has the effect of deviating the jet across a total angle of greater than 0° and equal to or less than 90°. 
     
     
         11 . The method of  claim 1 , wherein the jet is supersonic. 
     
     
         12 . The method of  claim 1 , wherein the jet has a flow rate of 200 Nm 3 /h to 4000 Nm 3 /h. 
     
     
         13 . The method of  claim 1 , wherein the lance further comprises a collar extending from the downstream end of the main body, the collar having a wall extending around the primary and secondary conduit outlets, an inner surface of the wall defining a vectoring space, wherein the jet becomes fixed with respect to the inner surface adjacent the secondary conduit outlet when injection of the second gas is initated therethrough. 
     
     
         14 . The method of  claim 1 , wherein:
 the lance has n secondary conduits each one of which extends between a respective inlet and a respective outlet, each of the secondary conduit outlets being disposed at the downstream end;   injection of the second gas is alternated between the n secondary conduits to alternatively deviate the jet between a respective n co-flows; and   n is an integer in the range of from 2-6.   
     
     
         15 . The method of  claim 14 , wherein the jet is swept across a straight line-shaped target area. 
     
     
         16 . The method of  claim 14 , wherein the jet is swept across a triangular target area. 
     
     
         17 . The method of  claim 14 , wherein the jet is swept across a quadrilateral target area. 
     
     
         18 . The method of  claim 1 , wherein the reaction space is an electric arc furnace. 
     
     
         19 . The method of  claim 1 , wherein the jet is ideally expanded. 
     
     
         20 . The method of  claim 1 , wherein the jet is under-expanded. 
     
     
         21 . The method of  claim 1 , wherein the reaction space is a Basic Oxygen Furnace (BOF) or a top and bottom mixed blown (QBOP) converter 
     
     
         22 . The method of  claim 1 , wherein the reaction space is an Argon Oxygen Decarburization (AOD) furnace 
     
     
         23 . The method of  claim 1 , wherein the reaction space is a Vacuum Oxygen Decarburization (VOD) furnace 
     
     
         24 . The method of  claim 1 , wherein the reaction space is a molten bath of non-ferrous metal. 
     
     
         25 . The method of  claim 1 , wherein the reaction space is a molten matte of sulfides of non-ferrous metals. 
     
     
         26 . The method of  claim 1 , wherein:
 the lance has a plurality of secondary conduits each one of which extends between a respective inlet and a respective outlet, each of the secondary conduit outlets being disposed at the downstream end; and   the second gas is injected through one of the plurality of secondary conduits to create an underexpanded co-flow and injected through another of the secondary conduits to create an overexpanded co-flow.   
     
     
         27 . The method of  claim 1 , wherein the jet has a circular cross-section. 
     
     
         28 . The method of  claim 1 , wherein a flow rate of the co-flow is in the range of from about 50 Nm3/h to about 1200 Nm 3 /h. 
     
     
         29 . A system for injecting a jet of a gas into an interior of a reaction space containing a liquid or solid reactant, comprising:
 a lance comprising a main body having a primary conduit and a secondary conduit formed therein and upstream and downstream ends, each of the primary and secondary conduits extending between a respective inlet and a respective outlet, the outlets being disposed at the downstream end, an outlet of the secondary conduit being disposed at a location adjacent the primary conduit outlet;   a source of a first gas at higher than ambient pressure fluidly communicating with the primary conduit; and   a source of a second gas at higher than ambient pressure in selective fluid communication with the secondary conduit, wherein the first and second gases are the same or different and the source of second gas is at a pressure higher than that of the source of the first gas.   
     
     
         30 . The system of  claim 29 , wherein the lance further comprises a collar extending from the downstream end of the main body, the collar having a continuous wall surrounding the primary and secondary conduit outlets, an inner surface of the wall defining a vectoring space through which a jet of the first gas may be injected from the outlet of the primary conduit.