GB449900A - Improvements in and relating to fuel nozzles for oil burning furnaces - Google Patents

Abstract

449,900. Spray-producers. AKT.-GES. BROWN, BOVERI, & CIE, Baden, Switzerland. Nov. 5, 1934, No. 31784. Convention date, Nov. 4, 1933. [Class 69 (iii)] [See also Group XI] A spray burner for liquid-fuel burning furnaces comprises at least two concentrically arranged atomizing nozzles, the discharges from which may be regulated in steps and the whirl imparting body of the inner nozzle acting as the control piston for regulating the discharge from the next larger nozzle. Fig. 2 shows one construction of burner in which the displacement of a piston 4 uncovers successively passages 2, 21 admitting the fuel tangentially to a cylindrical chamber 1 for discharge from a nozzle aperture 3. When all the passages leading to the chamber 1 have been uncovered an abutment 9 on the piston 4 engages a flange 35 on a spring-pressed block 10 in which the chamber 1 and nozzle aperture 3 are formed so that a further upward movement of the piston 4 raises the block 10 and uncovers successively bores 7, 7<1>, 7<11> leading to a nozzle aperture 5. The burner is preferably so dimensioned that the fuel entering through the first bore 7 is approximately the same as when all the passages 2, 2<1> leading to the chamber 1 are uncovered. Fig. 3 shows a modification in which a cylinder 15 containing the whirl chamber for the nozzle 3 is formed with a cylindrical extension 16 slidable in a skirt 24 to which fuel is admitted through a groove 19 in the control piston 20 to assist the pressure of a spring 17. When the piston 20 has been raised sufficiently for the groove 19 to be covered by the edge 21 of the casing an outlet passage 22 in the member 20 is uncovered. The piston is then raised by the fuel pressure in the space 23 to uncover the bores 7, 7<1> leading to the nozzle 5. In a further modification shown in Fig. 5, a metal bellows 26 is substituted for the parts 16, 24 and the fuel escapes from the bellows through holes 31, 32 in the piston 20 when a spring-loaded sleeve 29 engages an abutment 28.