DUST-SYSTEM Russian patent published in 2002 - IPC

FIELD: thermal engineering; thermal power stations. SUBSTANCE: dust-system has dust-concentrator 1 connected to milling device 17 by means of tangential inlet valve 13; discharge pipe 27 of dust-concentrator is joined to suction end of milling device. Some dust is burnt in concentrated-mixture pipe connection 2; heat released in the process serves to start coaxially arranged main and discharge burners; main burner is placed inside discharge burner. Concentrated-mixture pipe connection 2 is double-walled structure with its mouth open towards burner; outlet end communicates with air supply pipe connection 23 passed through slightly dusted agent discharge duct 9. Additional gas medium pipe 12 connected to hot air supply and accommodating ignition device 25; outlet end of the latter is installed level with smaller base of splitter 11. Air-fuel mixture is fed upon turning on starting device 25, ignited in pipe connection 2 and lights up air-fuel mixture coming from burners 21 and 22. Dust-system provides for reducing emission of nitrogen oxides due to reducing them in reducing medium formed in the course of burning with lack of air in main and discharge burners. Remaining air and tertiary air coming from walls of pipe connection 2 and from nozzles 24, respectively, is brought to clearance between burners. Staged ignition and subsequent burning ensure steady burning and low emission of oxides. EFFECT: provision for starting boiler without using dust bin due to precombustion of some portion of dust. 1 dwg