BOILER FURNACE Russian patent published in 1997 - IPC

FIELD: burning non-homogeneous coarse-grained fuels, mainly timber wastes. SUBSTANCE: boiler furnace has flue gas cooling chamber 1 with ash hopper formed by slopes 2a,b of walls of cooling chamber 1. Slope 2b of ash hopper is provided with port 2c. Boiler furnace contains also primary furnace 3 which is brought in communication with cooling chamber 1 through port 2c. In lower portion of primary furnace 3 there is grate 5 located above slotted mouth of ash hopper where preparation and ignition of fuel will be performed. Riddlings afterburner chamber 6 is located under ash hopper mouth. Chamber 6 is provided with outlet nozzle 8 which brings this chamber in communication with cooling chamber 1 through ash hopper mouth. Walls of outlet nozzle are inclined to such position that its longitudinal axis passes along slope of ash hopper located opposite slope 2a where port 2c is provided. Cooling chamber 1 is additionally provided with nozzle 9 for feeding the air which is located on the same wall along whose slope axis of outlet nozzle of chamber 6 passes. During operation of furnace, fuel is first fed to grate 5 where it is partially dried and ignited, after which it is transferred to cooling chamber 1. Small and medium particles of fuel are fed by air flows escaping from ash hopper mouth to cooling chamber 1 where zone of vortex motion of gases is formed due to interaction of above-mentioned flow with flow escaping from air nozzle 9 located on wall of cooling chamber 1. Fuel particles are entrapped in vortex flow where they are finally burnt. Large particles of fuel drop to chamber 6 through nozzle 8 where they are partially dried and cracked. Particles of fuel thus prepared are entrapped by air flow of undergrate blast and are returned to cooling chamber 1 where they are burnt in vortex flow. EFFECT: enhanced efficiency. 1 dwg