Device and method for spraying a combustible liquid

Abstract

The invention relates to devices and methods for the assisted internal spraying of a combustible liquid, wherein the combustible liquid is fed into a combustion area through a passage which ends in an outlet opening and into which spray gas is fed via a plurality of channels, the passage including a narrow portion and a wider but relatively short pre-spray chamber downstream from the narrow portion, the channels including small-diameter end sections tangentially leading into the narrow portion of the passage near the input opening of the chamber such that the spray gas impacts the combustible liquid and imparts a helical movement to the combustible liquid.

1 - 15 . (canceled) 
     
     
         16 . An injector for injecting an atomized jet spray of a combustible liquid through an outlet opening into a combustion zone situated downstream of the outlet opening of the injector, said injector comprising an internal assisted atomization unit that comprises a downstream injection face comprising said outlet opening, a combustible-liquid passage with an open downstream end, and two to six atomization gas ducts, wherein:
 said passage has a longitudinal axis of symmetry defining a direction Df of flow of the combustible liquid and a substantially circular variable cross section;   said passage passing through said atomization unit and comprising a narrow part having a diameter φf, and a preatomization chamber of diameter greater than φf downstream of the narrow part;   said preatomization chamber having an inlet opening and ending at said outlet opening which is situated opposite said inlet opening, a length Lc in said direction Df between said inlet opening and said outlet opening, and a mean diameter φc;   said narrow part opening into said preatomization chamber via said inlet opening;   said passage ending at its downstream end in said outlet opening of said injector;   each of said ducts comprising a terminal section having a diameter φg, where φg<φf, each terminal section defining an associated direction of flow of the atomization gas and opening into said narrow part of said passage near said inlet opening of said preatomization chamber so that each of said associated directions of flow forms an angle Ωgf of between 30° and 90° with the direction of flow Df;   said terminal sections open into said narrow part at a tangent to said narrow part so that the atomization gas impinges on the combustible liquid and imparts a helical movement to the combustible liquid; and   said length Lc of said preatomization chamber is less than or equal to a mean diameter φc of said preatomization chamber.   
     
     
         17 . The injector of  claim 16 , wherein said atomization unit is in one piece. 
     
     
         18 . The injector of  claim 16 , wherein 0.2×φc<Lc≦φc, preferably 0.2×φc<Lc≦0.5×φc. 
     
     
         19 . The injector of  claim 16 , wherein 0.2×φc<Lc≦0.5×φc. 
     
     
         20 . The injector of  claim 16 , wherein said preatomization chamber comprises at least one substantially cylindrical portion. 
     
     
         21 . The injector of  claim 16 , wherein each of said associated directions of flow forms an angle Ωgf of between 35° and 85° with the direction of flow Df, preferably of between 40° and 80°. 
     
     
         22 . The injector of  claim 16 , wherein each of said associated directions of flow forms an angle Ωgf of between 40° and 80° with the direction of flow Df. 
     
     
         23 . The injector of  claim 16 , wherein 1.0<φc/φf<3.0. 
     
     
         24 . The injector of  claim 16 , wherein 0.1<φg/φf<1.0. 
     
     
         25 . The injector of  claim 16 , wherein 1.1<φc/φf<2.0. 
     
     
         26 . The injector of  claim 16 , wherein 0.2<φg/φf<0.8. 
     
     
         27 . A burner for burning a combustible liquid, comprising the injector of  claim 16 . 
     
     
         28 . A furnace for burning a combustible liquid comprising a hearth equipped with at least one injector according to  claim 16  and a combustion zone downstream of the outlet opening of said injector. 
     
     
         29 . A furnace for burning a combustible liquid comprising a hearth equipped with at least one burner according to  claim 27 . 
     
     
         30 . A method for assisted internal atomization of a combustible liquid using the injector of  claim 16 , said method comprising the step of supplying the passage is supplied with combustible liquid and the ducts are supplied with pressurized atomization gas, so that:
 the combustible liquid has a flow velocity Vf in the narrow part of the passage,   the atomization gas has flow velocities Vg in the terminal sections of the ducts, with Vg>Vf, and   the atomization gas impinges on the combustible liquid and imparts a helical movement to the combustible liquid,   
       wherein the atomized combustible liquid is injected into a combustion zone through the outlet opening of the injector. 
     
     
         31 . The method of  claim 30 , wherein the ducts are supplied with pressurized atomization gas in such a way that the flow velocities Vg of the atomization gas in the terminal sections of the ducts are greater than 80 m/s. 
     
     
         32 . The method of  claim 30 , wherein the ducts are supplied with pressurized atomization gas in such a way that the flow velocities Vg of the atomization gas in the terminal sections of the ducts are greater than 80 m/s and less than 600 m/s. 
     
     
         33 . The method of  claim 30 , wherein the passage is supplied with combustible liquid and the ducts are supplied with pressurized atomization gas so as to obtain an atomized jet spray of combustible liquid in the gas leaving the chamber with an ejection velocity comprised between 1 and 400 m/s, preferably between 100 and 350 m/s. 
     
     
         34 . The method of  claim 30 , wherein the passage is supplied with combustible liquid and the ducts are supplied with pressurized atomization gas so as to obtain an atomized jet spray of combustible liquid in the gas leaving the chamber with an ejection velocity comprised between 100 and 350 m/s. 
     
     
         35 . The method of  claim 30 , wherein the ducts are supplied with the pressurized atomization gas in such a way that the atomization gas is at a pressure of between 1 and 10 bar in the terminal sections of the ducts. 
     
     
         36 . A method for burning a combustible liquid in a hearth, comprising the steps of:
 supplying the passage is supplied with combustible liquid and the ducts are supplied with pressurized atomization gas, so that:
 the combustible liquid has a flow velocity Vf in the narrow part of the passage, 
 the atomization gas has flow velocities Vg in the terminal sections of the ducts, with Vg>Vf, and 
 the atomization gas impinges on the combustible liquid and imparts a helical movement to the combustible liquid, 
   
       wherein the atomized combustible liquid is injected into a combustion zone through the outlet opening of the injector; and
 combusting the combustible liquid in the combustion zone with an oxidant in this combustion zone, the combustion zone being situated inside a hearth.