GB310881A - Improvements in burners for gaseous, liquid or powdered solid fuel - Google Patents

Abstract

310,881. Andrieux, P. J. J., (Assignee of Soc. Generale des Chaux et Ciments). May 2, 1928, [Convention date], Pulverulent-fuel and atmospheric gas and vapour burners.-A burner for the combustion of a mixture pulverized, liquid, or gaseous fuel and a fluid supporting combustion comprises a hollow body or tube traversed by the mixture an elongated core arranged within and extending beyond the body or tube and defining therein an annular channel of decreasing cross section, the length of the core being many times its diameter and the mixture being delivered in the form of a hollow sheath. The portion of the core extending beyond the body or tube is surrounded by a tube providing an annular passage through which air is induced by the fuel mixture. Fig. 1 shows a burner in which a mixture of powdered fuel and primary air delivered by a blower from a pipe 1 to a conduit 3 passes through an annular passage between an outer casing 4, 5, 6 and an inner cone 7, 8 to an annular discharge nozzle formed between an outer casing 10 and the core 8. The part 4 of the outer casing and the part 6 of the inner core are both tapered outwardly, the parts 5, 8 are of uniform diameter, while the part 6 tapers inwardly, so that on the fuel mixture reaching the outlet from the part 6 its velocity has reached a maximum and, owing to the ejector action produced, additional air will be drawn in at the tapered end 12 of the casing 10. The end 12 may be adjustable so that the amount of additional air drawn in mav be varied. The core 7, 8 may be made hollow and additional air may be supplied to it through a pipe 13. The burner therefore discharges, as shown in Fig. 4, a layer of fuel mixed with air enclosing an air jet 14 and surrounded by an annular air stream 16, an ellipsoidal flame being produced in which the strongest combustion occurs at the outer surface. The additional air currents 14, 16 may be heated bv contact with hot material being cooled in a cold part of the furnace or by separate heating means. In the revolving furnace 17, Fig. 4, such as used in the cement and metallurgical industries, the additional air 16 is heated by passing from the conduit 21 over the material cooling in the region m - - n of the furnace. The joint between the pipe 1 and conduit 3 is formed with inclined surfaces 2 so as to allow of angular adjustment of the burner.