Tubular vortex air cleaner

Claim 1

An air cleaner particularly suited for use as one of an array of closely spaced air cleaners for efficiently removing contaminant particles from relatively high velocity air with a minimum pressure drop, comprising, in combination, a tubular body defining an inlet opening at one end, an outlet opening at the opposite end, and a central passage therebetween; a deflector coaxially mounted in the passage in a fixed position adjacent the inlet opening, said deflector having a plurality of helical vanes supported on a central hub, and abutting the wall of the tubular body, said vanes being positioned at an angle to the line of airlfow from the inlet opening to the outlet opening so as to create a vortex stream in the influent air which concentrates the contaminant particles in the air at the periphery of the central passage, thereby leaving the air at the center of the central passage relatively clean; a generally tubular outlet member coaxially positioned at the outlet end of the tubular body, having an inlet opening at one end disposed within the central passage adjacent the outlet of the tubular body, an outlet opening at the opposite end, and a central passage therebetween for delivery of clean air from the central passage of the tubular body, the inlet opening of said member being of lesser diameter than the outlet opening of the tubular body and defining an annular contaminant exhaust passage for the passage of contaminant particles between the exterior of the outlet member and the wall of the tubular body; the tubular body of uniform diameter for the major portion of its length from the inlet end to the end of the deflector, and at the outlet end in the region from the downstream end of the deflector to the outlet, adjacent the outlet member, having a diameter ranging from zero taper to a gradual outward taper of up to about 10*; and a circumferential constriction in the central passage and positioned adjacent the inlet opening and upstream of the deflector vanes, said constriction being of lesser diameter than the adjacent portions of the central passage both upstream and downstream thereof, and a convexly curved circumferential surface extending from the wall of the tubular body into the central passage from the inlet opening of the tubular body to the constriction to define with the constriction a smoothly curved but restricted air cleaner entrance configuration, to guide flow into the central passage with a minimum of pressure drop for a given particle removal efficiency.