Self-cleaning screening device
OwnerRobert E. Freyinventor
Life of this patent
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Abstract
The invention comprises a screening device for separating fine particles from a stream of air and a particulate mixture containing coarse and fines which includes a box-like hollow housing tilted downwardly at an acute angle. The housing contains a plurality of elongated screening elements and an air cleaning device consisting of a blowpipe and a series of nozzles directed at the screening elements through Venturi tubes. At periodic intervals a jet or pulse of air is injected into the Venturi tubes to reverse air flow and rid the screen elements of adhered coarse particles. Substantially complete fines removal can be achieved by employing a recycling loop between the coarse particle outlet and inlet of the housing.
Claims18
An apparatus for continuously separating a mixture of fine and coarse particles comprising:
- (a) a hollow housing having a tubesheet located therein tilted downwardly at an acute angle from the horizontal, said tubesheet separating said housing into a lower fines outlet chamber and an upper pre-screen chamber;
- (b) a plurality of Venturi tubes mounted on said tubesheet;
- (c) a plurality of screen elements mounted on said Venturi tubes;
- (d) means located in said fines outlet chamber for introducing a pulse of a compressed gas through said Venturi tubes to the screens;
- (e) an inlet for introducing air and said mixture of fine and coarse particles to said pre-screen chamber mounted in said housing;
- (f) an outlet for coarse particles mounted on said housing and communicating with said pre-screen chamber;
- and
- (g) an outlet for fine particles mounted in said housing and communicating with said fines outlet chamber.
An apparatus for continuously separating a mixture of fine and coarse particles comprising:
- (a) a hollow housing having a tubesheet located therein, said tubesheet separating said housing into a fines outlet chamber and a pre-screen chamber;
- (b) a plurality of Venturi tubes mounted on said tubesheet;
- (c) a plurality of screen elements mounted on said Venturi tubes;
- (d) means located in said fines outlet chamber for introducing a pulse of a compressed gas through said Venturi tubes to the screen elements;
- (e) an inlet for introducing air and said mixture of fine and coarse particles to said pre-screen chamber mounted in said housing;
- (f) an outlet for coarse particles mounted on said housing and communicating with said pre-screen chamber;
- and
- (g) an outlet for fine particles mounted in said housing and communicating with said fines outlet chamber.
Dependencies are inferred from the claim text.