FURNACE THROAT SHUT-OFF DEVICE Russian patent published in 2003 - IPC

FIELD: thermal engineering; boiler furnaces. SUBSTANCE: adjustable shut-off device used to shut off boiler furnace throat when retracting draw-out tubes of soot blowers has throat-mounted duct, shutter hinged to duct through articulated joint with horizontal axis of revolution disposed at level of throat upper edge, shutter opening facility in the form of soot-blower draw-out tube with nozzle head; shutter is made in the form of cylindrical quadrant whose axis is aligned with that of articulated joint; duct is provided with seat disposed above articulated-joint level for receiving shutter; device also has stop. Shutter is provided with radial stop plate mounted at certain angle to radial wall engageable with nozzle head; draw-out tube is provided with stop member mounted for engaging stop plate during reverse travel of draw-out tube Diameter of nozzle head is greater than that of draw-out tube. Nozzle head is coupled to the latter through taper joint; stop plate has notch whose width is greater than diameter of draw-out tube and smaller than that of nozzle head. Stop plate follows throat shape. EFFECT: enhanced reliability of device. 4 cl, 2 dwg