US4543181A — Medium consistency flat disk pressure screen

Claim 1

Independent Claim 254 words

Apparatus for effecting screening of a suspension, comprising: an annular substantially flat plate screen; a closed chamber; means for stationarily mounting said annular screen within said chamber; an inlet to said chamber substantially concentric with said annular screen; an outlet from said chamber on the opposite side of the said screen from said inlet; a disk comprising first and second faces, said first face having a plurality of vanes mounted thereon and extending generally radially therealong, at least some of said vanes including an end portion disposed raidally outwardly from said disk periphery; means for mounting said disk for rotation in said chamber with said disk substantially parallel to said screen and said vanes spaced a small axial distance from said screen so that said vanes move suspension over said flat plate screen; a rejects outlet extending radially outwardly from said chamber and adjacent the periphery of said disk; means for rotating said disk at a speed sufficient for it to effect fluidization of suspension at the screen area as the suspension is being moved over the screen area by the disk vanes; and the disk being mounted in juxtaposition to the screen, and in cooperation with the inlet and outlets, so that the volume of suspension to be fluidized at the screen area is relatively low; and means for recirculating a portion of reject material from the second face of the disk to the first face thereof, said means comprising means defining a plurality of openings in said disk adjacent the center thereof.

Claim 2

Dependent Claim 254 words

Apparatus for effecting screening of a suspension, comprising: an annular substantially flat plate screen; a closed chamber; means for stationarily mounting said annular screen within said chamber; an inlet to said chamber substantially concentric with said annular screen; an outlet from said chamber on the opposite side of the said screen from said inlet; a disk comprising first and second faces, said first face having a plurality of vanes mounted thereon and extending generally radially therealong, at least some of said vanes including an end portion disposed raidally outwardly from said disk periphery; means for mounting said disk for rotation in said chamber with said disk substantially parallel to said screen and said vanes spaced a small axial distance from said screen so that said vanes move suspension over said flat plate screen; a rejects outlet extending radially outwardly from said chamber and adjacent the periphery of said disk; means for rotating said disk at a speed sufficient for it to effect fluidization of suspension at the screen area as the suspension is being moved over the screen area by the disk vanes; and the disk being mounted in juxtaposition to the screen, and in cooperation with the inlet and outlets, so that the volume of suspension to be fluidized at the screen area is relatively low; and means for recirculating a portion of reject material from the second face of the disk to the first face thereof, said means comprising means defining a plurality of openings in said disk adjacent the center thereof.

Claim 3

Dependent Claim 19 words

Apparatus as recited in claim 1 wherein said openings defined in said disk are in-line with said suspension inlet.

Claim 4

Dependent Claim 24 words

Apparatus as recited in claim 2 wherein said openings in said disk are all radially interior of the radially interior-most portions of said vanes.

Claim 5

Dependent Claim 40 words

Apparatus as recited in claim 3 further comprising a plurality of impeller blades mounted on the second face of said disk, and extending generally radially, said impeller blades being fewer in number and/or of less radial extent than said vanes.

Claim 6

Dependent Claim 18 words

Apparatus as recited in claim 4 wherein said impeller blades are contained within the periphery of said disk.

Claim 7

Dependent Claim 24 words

Apparatus as recited in claim 5 wherein said openings in said disk are radially inward of the radially inward-most portions of said impeller blades.

Claim 8

Dependent Claim 118 words

Apparatus as recited in claim 1 wherein said chamber comprises a first chamber, said screen comprises a first screen, and said disk comprises a first disk; and further comprising: a second chamber; a second substantially flat plate screen; means for mounting said second screen within said second chamber, substantially parallel to said first screen; said suspension outlet from said first chamber comprising a suspension inlet to said second chamber; a suspension outlet from said second chamber; a rejects outlet from said second chamber, said rejects outlet in communication with said suspension inlet to said first chamber; and means for mounting said second disk so that it is substantially parallel to said second screen and adjacent said second screen.

Claim 9

Dependent Claim 41 words

Apparatus as recited in claim 1 wherein said screen is substantially vertical, and wherein the axis of rotation of said disk is substantially horizontal, and wherein the inlet has a cross-sectional area larger than the combined cross-sectional areas of the outlets.

Claim 10

Dependent Claim 250 words

Apparatus for effecting screening of a suspension, comprising: an annular substantially flat plate screen; a closed chamber; means for stationarily mounting said annular screen within said chamber; an inlet to said chamber substantially concentric with said annular screen; an outlet from said chamber on the opposite side of the said screen from said inlet; a disk comprising first and second faces, said first face having a plurality of vanes mounted thereon and extending generally radially therealong, at least some of said vanes including an end portion disposed radially outwardly from said disk periphery; means for mounting said disk for rotation in said chamber with said disk substantially parallel to said screen and said vanes spaced a small axial distance from said screen so that said vanes move suspension over said flat plate screen; a rejects outlet extending radially outwardly from said chamber and adjacent the periphery of said disk; means for rotating said disk at a speed sufficient for it to effect fluidization of suspension at the screen area as the suspension is being moved over the screen area by the disk vanes; and the disk being mounted in juxtaposition to the screen, and in cooperation with the inlet and outlets, so that the volume of suspension to be fluidized at the screen area is relatively low; and a plurality of impeller blades mounted on the second face of said disk, and extending generally radially, said impeller blades being fewer in number and/or of less radial extent than said vanes.

Claim 11

Dependent Claim 250 words

Apparatus for effecting screening of a suspension, comprising: an annular substantially flat plate screen; a closed chamber; means for stationarily mounting said annular screen within said chamber; an inlet to said chamber substantially concentric with said annular screen; an outlet from said chamber on the opposite side of the said screen from said inlet; a disk comprising first and second faces, said first face having a plurality of vanes mounted thereon and extending generally radially therealong, at least some of said vanes including an end portion disposed radially outwardly from said disk periphery; means for mounting said disk for rotation in said chamber with said disk substantially parallel to said screen and said vanes spaced a small axial distance from said screen so that said vanes move suspension over said flat plate screen; a rejects outlet extending radially outwardly from said chamber and adjacent the periphery of said disk; means for rotating said disk at a speed sufficient for it to effect fluidization of suspension at the screen area as the suspension is being moved over the screen area by the disk vanes; and the disk being mounted in juxtaposition to the screen, and in cooperation with the inlet and outlets, so that the volume of suspension to be fluidized at the screen area is relatively low; and a plurality of impeller blades mounted on the second face of said disk, and extending generally radially, said impeller blades being fewer in number and/or of less radial extent than said vanes.

Claim 12

Dependent Claim 44 words

Apparatus as recited in claim 9 further comprising: means for recirculating a portion of reject material from the second face of the disk to the first face thereof, said means comprising means defining a plurality of openings in said disk adjacent the center thereof.

Claim 13

Dependent Claim 41 words

Apparatus as recited in claim 9 wherein said screen is substantially vertical, and wherein the axis of rotation of said disk is substantially horizontal, and wherein the inlet has a cross-sectional area larger than the combined cross-sectional areas of the outlets.

Claim 14

Dependent Claim 200 words

Apparatus for screening a suspension, comprising: a first chamber; a first substantially flat plate screen; means for mounting said first screen stationarily in said first chamber; a suspension inlet to said first chamber; a suspension outlet from said first chamber; a rejects outlet from said first chamber; a first disk; means for mounting said first disk for rotation within said first chamber, and so that it is substatially parallel to said first screen; a second chamber; a second substantially flat plate screen; means for stationarily mounting said screen in said second chamber; a suspension inlet into said second chamber, said suspension inlet in communication with said suspension outlet from said first chamber; a suspension outlet from said second chamber; a rejects outlet from said second chamber, said rejects outlet from said second chamber being in communication with said suspension inlet to said first chamber; a second disk; and means for mounting said second disk within said second chamber so that it is substantially parallel to said second screen, and for rotation within said second chamber; said first and second substantially flat plate screens being substantially vertical, and said first and second disks each being rotatable about a substantially horizontal axis.

Claim 15

Dependent Claim 200 words

Apparatus for screening a suspension, comprising: a first chamber; a first substantially flat plate screen; means for mounting said first screen stationarily in said first chamber; a suspension inlet to said first chamber; a suspension outlet from said first chamber; a rejects outlet from said first chamber; a first disk; means for mounting said first disk for rotation within said first chamber, and so that it is substatially parallel to said first screen; a second chamber; a second substantially flat plate screen; means for stationarily mounting said screen in said second chamber; a suspension inlet into said second chamber, said suspension inlet in communication with said suspension outlet from said first chamber; a suspension outlet from said second chamber; a rejects outlet from said second chamber, said rejects outlet from said second chamber being in communication with said suspension inlet to said first chamber; a second disk; and means for mounting said second disk within said second chamber so that it is substantially parallel to said second screen, and for rotation within said second chamber; said first and second substantially flat plate screens being substantially vertical, and said first and second disks each being rotatable about a substantially horizontal axis.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1988-09-23	1989-03-25	1989-09-24	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1992-09-23	1993-03-25	1993-09-24	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1996-09-23	1997-03-25	1997-09-24	$7700.00	Window Closed / Lapsed

Medium consistency flat disk pressure screen

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