GB190901025A - Improvements in Mechanically Stoked Furnaces. - Google Patents

Abstract

1025. Howden & Co., J., and Todd, D. R. Jan. 15. Fire-bars and grates; mechanical stoking.-In a forced-draught furnace adapted to be alternatively hand-fired or mechanically stoked, a set of stationary perforated air-supplying hollow fire-bars are set longitudinally so as to accommodate in each of the spaces between them a series of projections on an endless chain of links, which are adapted to push the fuel along the grate mechanically and to prevent clinkering &c. Fig. 1 shows a steam-generator furnace mechanically fed with fuel by a hopper 17 and a rotating drum 19 ; the fuel slides down the face of an inclined sliding door 18 to a series of trough-like dead-plates 6, whence it is pushed forwards by reciprocating plungers 7, and burns upon the perforated #-section fire-bars 1, shown in section in Fig. 2. Beneath the grate, and in the closed ash pit or compressed-air chamber 11, is a group of endless chains 3, consisting of toothed links 3<e> and short connecting-links 3<b> with wheels 3<c> running on rails 3<d>. The plungers 7 are each fitted with antifriction rollers 8 and shields 10, and are connected to a cross-bar 13 which slides on a guide-bar 13<a> at each side of the furnace. They are operated by a lever 20 on a rocking-shaft 21, which also, by means of levers 22, 24 connected by a link 23, operates the ratchet-like driving-gear of the spindle 15 carrying the sprocket-wheels 14 at the front ends of the chains 3. Each link of the chain 3 has a pair of flanges 3<g> which fit under the lower edges of the fire-bars 1, and the closure is completed by strips 1<a>, so that air enters the furnace only through the slits or perforations 5 in the fire-bars. The tension of the chains may be adjusted by gearing 27, 28, 29 operating screws 26<a> which pass through screwed portions of the spindles 15<a>. These spindles are supported by horizontal bearing - rods 26<b>. A spring - plate 31 presses lightly on the links 3 and forms an air seal, and also directs the clinker &c. to the ash-pit.