Furnace gas cleaning and cooling apparatus

Claim 1

THE COMBINATION WITH A GAS WASHER FOR BLAST FURNACE GASES AND A DUDT EXTENDING DOWNWARDLY ALONG THE OUTSIDE OF THE WASHER FOR CONVEYING GASES FROM A BLAST FURNACE TO THE WASHER, THE DUCT BEING OF SMALLER DIAMETER THAN THE WASHER SO THAT A HIGHER GAS VELOCITY IS MAINTAINED THEREIN THAN IN THE WASHER, OF AN EXPANSION CHAMBER AT THE BOTTOM OF THE DUCT IN WHICH THE DUCT PROJECTS AND TERMINTES, A SECOND DUCT LEADING FROM THE UPPER PORTION OF THE EXPANSION CHAMBER AT A LEVEL ABOVE THE LEVEL AT WHICH THE FIRST DUCT TERMINATES INTO THE LOWER PORTION OF THE GAS WASHER, MEANS PROVIDING A RESTRICTING ORIFICE IN THE SAID FIRST DUCT FOR INCREASING THE VELOCITY OF GAS FLOW THROUGH THE ORIFICE, A NOZZLE IN THE DUCT ABOVE THE ORIFICE POSITIONED TO PROJECT A SPRAY OF WATER THROUGH THE ORIFICE, MEANS AT THE BOTTOM OF THE EXPANSION CHAMBER FOR CARRYING AWAY WATER AND ENTRAINED SOLIDS DISCHARGED BY THE ACTION OF SAID SPRAY INTO THE GAS AT THE ORIFICE, WHEREBY A SUBSTANTIAL VOLUME OF DUST IS REMOVED FROM THE GAS BEFORE IT ENTERS THE WASHER, MEANS AT THE OUTLET SIDE OF SAID RESTRICTING ORIFICE FOR VARYING THE PRESSURE DROP BETWEEN THE UPSTREAM AND DOWNSTREAM SIDES OF THE ORIFICE WHEREBY THE IMPEDANCE TO GAS FLOW THROUGH THE SAID ORIFICES MAY BE INCREASED AS THE GAS VOLUME DECREASES AND DECREASED AS THE GAS VOLUME INCREASES TO MAINTAIN THE VELOCITY OF THE GAS IN A CONTROLLED RANGE, AND MEANS ACCESSIBLE AT THE EXTERIOR OF SAID FIRST-NAMED DUCT FOR ADJUSTING SAID LAST-NAMED MEANS.