Rotating blade type evaporators

Claim 1

A ROTATING BLADE TYPE EVAPORATOR COMPRISING A VERTICALLY-DISPOSED ELONGATED EVAPORATOR SHELL OF CIRCULAR SECTION THROUGHOUT ITS LENGTH HAVING AN UPPER PORTION, A LOWER PORTION, AND AN INTERMEDIATE PORTION FORMIUNG A CONTINUOUS SMOOTH INTERIOR WALL, MEANS FOR HEATING THE WALLS OF THE INTERMEDIATE PORTION ONLY, MEANS FOR DELIVERING MATERIAL TO BE CONCENTRATED BY EVAPORATION INTO THEUPPER PORTION, A ROTOR EXTENDING LONGITUDINALLY OF THE SHELL HAVING MAIN VANES THEREON FOR SPREADING MATERIAL OVER THE INTERIOR OF THE SHELL AND AGITATING THE SAME, THE VANES EXTENDING FROM THE UPPER PORTION TO THE LOWER END OF THE INTERMEDIATE PORTION, A BOTTOM COVER PLATE CLOSING THE END OF SAID LOWER PORTION, THE LOWER PORTION OF THE SHELL HAVING AN OPEN AREA THEREIN EXTENDING UPWARDLY FROM THE BOTTOM COVER PLATE THROUGH WHICH BOTH LIQUID AND VAPOR ARE DISCHARGED FROM THE EVAPORATOR IN THE SIDE WALL THEREOF, AN IMPELLOR ON THE LOWER END OF THE ROTOR WITHIN SAID LOWER PORTION OF THE SHELL HAVING OTHER VERTICAL CENTRIFUGALLY ACTING VANES SEPARATED FROM AND OUT OF VERTICAL ALIGNMENT WITH THE MAIN VANES FOR EXPELLING PRODUCT AND VAPORS PERIPHERALLY