Classifying centrifugal separator

Claim 1

A classifying separator for removing entrained particles from gaseous materials comprising: a vertical outer vessel shell having an upper cylindrical portion and closed at the top thereof and tapered downwardly at the bottom thereof to form a first restricted bottom discharge opening for the removal of solids; a first cylindrical sleeve concentrically positioned within the first vessel and spaced inwardly thereof with its upper end fixed in an air sealing relation to the top of the first vessel and its lower end free therewithin, whereby to provide a first circular annulus between the shell and first sleeve open at its lower end; a vertical inner vessel shell having an upper cylindrical portion concentrically positioned within said first sleeve and spaced inwardly thereof, said inner shell tapered downwardly at the bottom thereof to form a restricted air sealed bottom discharge for said inner vessel; the inner vessel shell spaced downwardly from the top of the outer shell to provide a continuous, circumferential gap thereover for passage inwards thereof of gas and gas entrained solids; the inner shell and first sleeve providing therebetween a second circular annulus open at its lower end; a second cylindrical sleeve concentrically positioned within the second shell and spaced inwardly therefrom and above the tapered portion of said inner vessel whereby to provide a third circular annulus between said inner vessel shell and second sleeve open at its lower end; the upper end of said second sleeve penetrating the outer vessel shell top closure to provide a gas discharge outlet; an inlet connected tangentially into the upper portion of said outer vessel shell for introducing gases and entrained solids to the first annulus, and substantially vertically oriented slotted passageways in the walls of the first and second sleeves for removing solids from the gaseous materials passing through the second annulus and inner sleeve, respectively.