GB415781A - Improvements in or relating to horizontal boiler furnaces - Google Patents

Abstract

415,781. Furnace grates ; firebridges. WOOD, G. R., 25, Easby Road, Bradford, Yorkshire, and DODWELL, A. E., Wentworth, Great West Road, Hounslow, Middlesex. March 3, 1933, No. 6451. [Class 51 (i).] The air supply to a horizontal boiler furnace passes through a distributer box 4 adapted to deliver into a hollow bridge 2 and to the fuel on the grate by way of longitudinal passages 9 formed by apertures in a series of transverse firebars, the distributer box having associated therewith means for apportioning the air supply. Air enters at the front of the furnace and is preheated during its passage beneath the grate to the rear of the furnace where it is deflected by a transverse baffle 7 and under the influence of steam injectors 6 passes through Venturi tubes 5 into the box 4. The box is of rectangular form and is provided with a plurality of forwardly directed tapering outlet tubes each delivering into one of the longitudinal grate passages 9. The proportion of air passing to the grate or through a transverse port 12 to the bridge is controlled by a pivoted damper 15 operated through link mechanism from the front of the furnace. In the form shown in Fig. 1 the bridge 2 is formed of arcuate bridge bars having in their side faces recesses which co-operate to form air passages 11. Depending webs 13 divide the bridge into a series of compartments and split up the air supply. In a modified form, Fig. 2, the bridge bars are of refractory material and the baffle 7 is in the form of a metallic plate having a lower hinged portion 7<x> which may be raised by means of a chain 19 so as to allow air to pass directly into the furnace tube behind the firebridge 2 when the steam injectors 6 are shut off.