GB266827A - Improvements relating to powdered fuel furnaces - Google Patents

Abstract

266,827. Helbig, A. B. Dec. 5, 1925. Pulverulent-fuel burners. - A mix. ture of powdered fuel and air from a supply conduit 1 issues into the furnace through a distributing device 2, Figs. 1 and 2, comprising a cone having in its under surface slots 3 communicating with a number of passages formed by vertical baffle-plate 5. The aggregate area of the passages substantially exceeds the cross-sectional area of the supply conduit so that the velocity of the fuel on entering the furnace is reduced considerably without substantially affecting the uniformity of the mixture. The fuel mixture on issuing from the slots 3 impinges on dispersing bars 4 and passes over parallel cooling pipes 8 arranged below the furnace inlet 6 to prevent premature ignition. The cooling pipes other than those embedded in the furnace walls may be provided with ridge pieces 9. In a modified construction the axis of the cone of the distributor is aligned either with the axis of the supply tube or downwardly inclined relatively thereto. Figs. 6 and 7 show another form of distributor having a cylindrical upper surface but tapered on its lower surface to form a. neck. The baffles 5 extend into the cylindrical part and increase in height from the feed end to the opposite end. The fuel inlet 6 is preferably rectangular, but may be flared. In a modification the cylindrical upper surface is downwardly inclined from the feed end. Fig. 12 show a further modification in which the fuel and air mixture issue from a distributor 2<a> through a conduit 3<a> into a box or chamber 10<a> fixed to the furnace inlet 6<a>, and additional air is supplied through an inlet 11<a> to dilute the fuel and air mixture before it enters the furnace. A plate 12<a> formed with perforations having a total area substantially equal to the cross-sectional area of the inlet 11<a> is arranged horizontally in the chamber 10<a> above the inlet from the conduit 3<a>. The distributor 2a may alternatively be arranged in the chamber 10<a> and be provided with several discharge slots.