US3876548A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Screening method and apparatus
Assignee: Hydrocyclonics Corp
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Filing: 1974-01-21
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Granted: 1975-04-08
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Expires: 1994-01-21
Abstract
Abstract A structure for dewatering solids uses a rotating cylindrical screen, with the water, after being separated from the solids, being used to clean the screen. The screen is continuously cleaned as it rotates, not only by the separated water, but by one or more wipers which are positioned to bear against the external surface of the screen. The combination of the separated water for self-cleaning and the cleaning action of the external wipers maintains the screen in a substantially solid-free state in those areas which receive the incoming stream of solids and water. The screen is made up of generally parallel bars, each bar having an outer face and immediately adjacent sides. The angle formed by a line perpendicular to the outer face and an immediately adjacent side is greater than about 7.degree. and less than about 45.degree.. The screen must have a minimum diameter of about 11 inches and a ratio of screen diameter to bar radial thickness greater than about 75.
Inventors
- 👤 Jr Donald P Welles
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:16
CPC Classifications
B; B01; B01D; B01D33/00; B01D33/06; B01D33/067; B01D33/073; B01D33/11; B01D33/27; B01D33/275; B01D33/35; B01D33/37; B01D33/39; B01D29/00; B01D29/44; B01D29/48
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
326 words
In a device for separating and dewatering the generally spongy solids from the liquid in sanitary sewage, food processing, meat packing and the like, including a cylindrical screen having a screening medium about its outer periphery made up of spaced circumferentially arranged, generally parallel bars surrounding a generally open interior, means supporting the screening medium for rotation about a generally horizontal axis so that the surface of the screening medium is rising on one side and descending on the other, means for rotating the screening medium, a headbox containing a liquid-solid medium to be separated directly adjacent the surface of the screening medium and opening against the rising side thereof above a horizontal plane through its axis, a solids discharge adjacent the outer surface of the screening medium and spaced from the headbox in the direction of its rotation and beyond a vertical plane through its axis, movement of the screening medium carrying the separated solids from the headbox toward the solids discharge with the majority of the liquid passing through the screening medium at the headbox and falling freely in a cascading column down to the bottom area of the screening medium toward the inner surface of the medium primarily in an area on the rising side below the horizontal plane through its axis, the bars that make up the screening medium each having a generally flat outer face which, as a group, make up a cylindrical, generally smooth exterior surface with limited openings between adjacent bars to effect maximum separation adjacent the headbox followed by transportation of the separated solids to the solids discharge, the bars having inwardly diverging sides which define upwardly opening cleaning troughs at the bottom of the cascading column, the side of one bar defining an included angle with the opposed side of an adjacent bar greater than about 14.degree. and less than about 90.degree., with ratio of screen diameter to radial bar thickness being no less than about 75.
Claim 2
Dependent Claim
326 words
In a device for separating and dewatering the generally spongy solids from the liquid in sanitary sewage, food processing, meat packing and the like, including a cylindrical screen having a screening medium about its outer periphery made up of spaced circumferentially arranged, generally parallel bars surrounding a generally open interior, means supporting the screening medium for rotation about a generally horizontal axis so that the surface of the screening medium is rising on one side and descending on the other, means for rotating the screening medium, a headbox containing a liquid-solid medium to be separated directly adjacent the surface of the screening medium and opening against the rising side thereof above a horizontal plane through its axis, a solids discharge adjacent the outer surface of the screening medium and spaced from the headbox in the direction of its rotation and beyond a vertical plane through its axis, movement of the screening medium carrying the separated solids from the headbox toward the solids discharge with the majority of the liquid passing through the screening medium at the headbox and falling freely in a cascading column down to the bottom area of the screening medium toward the inner surface of the medium primarily in an area on the rising side below the horizontal plane through its axis, the bars that make up the screening medium each having a generally flat outer face which, as a group, make up a cylindrical, generally smooth exterior surface with limited openings between adjacent bars to effect maximum separation adjacent the headbox followed by transportation of the separated solids to the solids discharge, the bars having inwardly diverging sides which define upwardly opening cleaning troughs at the bottom of the cascading column, the side of one bar defining an included angle with the opposed side of an adjacent bar greater than about 14.degree. and less than about 90.degree., with ratio of screen diameter to radial bar thickness being no less than about 75.
Claim 3
Dependent Claim
25 words
The structure of claim 1 further characterized in that the included angle between the opposed sides of adjacent bars is on the order of 26.degree..
Claim 4
Dependent Claim
21 words
The structure of claim 1 further characterized in that the separation of the bars is on the order of 0.060 inches.
Claim 5
Dependent Claim
303 words
In a device for separating and dewatering the generally spongy solids from the liquid in sanitary sewage, food processing, meat packing and the like, including a cylindrical screen having a screening medium about its outer periphery made up of spaced circumferentially arranged, generally parallel bars surrounding a generally open interior, the medium being at least 11 inches in diameter so as to provide a substantial free fall of the liquid resulting in appreciable impact when the liquid hits the bottom area of the medium, means supporting the screening medium for rotation and means for rotating it, a headbox containing a liquid-solid medium to be separated and opening against the medium at a point above a plane through its axis, a solids discharge adjacent the outer surface of the screening medium and spaced from the headbox in the direction of its rotation, movement of the screening medium carrying the separated solids from the headbox toward the solids discharge with the liquid passing through the screening medium and falling freely in a cascading free column down to the bottom area of the screening medium, the bars that make up the screening medium each having a generally flat outer face which, as a group, make up a cylindrical, generally smooth exterior surface with limited openings between adjacent bars to effect maximum separation adjacent the headbox followed by transportation of the separated solids to the solids discharge, the bars having inwardly diverging sides which define downwardly opening separating slots at the top and upwardly opening liquid-collecting cleaning troughs at the bottom of the cascading column, the side of one bar defining an included angle with the opposed side of an adjacent bar greater than about 14.degree. and less than about 90.degree., with a ratio of screen diameter to radial bar thickness being no less than about 75.
Claim 6
Dependent Claim
303 words
In a device for separating and dewatering the generally spongy solids from the liquid in sanitary sewage, food processing, meat packing and the like, including a cylindrical screen having a screening medium about its outer periphery made up of spaced circumferentially arranged, generally parallel bars surrounding a generally open interior, the medium being at least 11 inches in diameter so as to provide a substantial free fall of the liquid resulting in appreciable impact when the liquid hits the bottom area of the medium, means supporting the screening medium for rotation and means for rotating it, a headbox containing a liquid-solid medium to be separated and opening against the medium at a point above a plane through its axis, a solids discharge adjacent the outer surface of the screening medium and spaced from the headbox in the direction of its rotation, movement of the screening medium carrying the separated solids from the headbox toward the solids discharge with the liquid passing through the screening medium and falling freely in a cascading free column down to the bottom area of the screening medium, the bars that make up the screening medium each having a generally flat outer face which, as a group, make up a cylindrical, generally smooth exterior surface with limited openings between adjacent bars to effect maximum separation adjacent the headbox followed by transportation of the separated solids to the solids discharge, the bars having inwardly diverging sides which define downwardly opening separating slots at the top and upwardly opening liquid-collecting cleaning troughs at the bottom of the cascading column, the side of one bar defining an included angle with the opposed side of an adjacent bar greater than about 14.degree. and less than about 90.degree., with a ratio of screen diameter to radial bar thickness being no less than about 75.
Claim 7
Dependent Claim
25 words
The structure of claim 4 further characterized in that the included angle between the opposed sides of adjacent bars is on the order of 26.degree..
Claim 8
Dependent Claim
33 words
The structure of claim 4 further characterized in that the separation of the bars is uniform, from one end of the screening medium to the other and on the order of 0.060 inches.
Claim 9
Dependent Claim
19 words
The structure of claim 4 further characterized in that the axis of the screening medium is arranged generally horizontal.
Claim 10
Dependent Claim
55 words
The structure of claim 4 further characterized in that the headbox is on one side of the screening medium and opens against the rising side thereof and the solids-discharge is on the other side of the screening medium beyond a vertical plane through the axis of the screening medium and on the descending side thereof.
Claim 11
Dependent Claim
312 words
In a device for separating and dewatering the generally spongy solids from the liquid in sanitary sewage, food processing, meat packing and the like, including a cylindrical screen having a screening medium about its outer periphery made up of spaced circumferentially arranged, generally parallel bars surrounding a generally open interior, the medium being at least 11 inches in diameter so as to provide a substantial free fall of the liquid resulting in appreciable impact when the liquid hits the bottom area of the medium, means supporting the screening medium for rotation and means for rotating it, a headbox containing a liquid-solid medium to be separated and opening against the medium at a point above a plane through its axis, a solids discharge adjacent the outer surface of the screening medium and spaced from the headbox in the direction of its rotation, movement of the screening medium carrying the separated solids from the headbox toward the solids discharge with the liquid passing through the screening medium and falling freely in a cascading free column down to the bottom area of the screening medium, the bars that make up the screening medium each having a generally flat outer face which, as a group, make up a cylindrical, generally smooth exterior surface with limited openings between adjacent bars to effect maximum separation adjacent the headbox followed by transportation of the separated solids to the solids discharge, the bars having inwardly diverging sides which define downwardly opening separating slots at the top and upwardly opening liquid-collecting cleaning troughs at the bottom of the cascading column with the included angle between the opposed sides of adjacent bars being at a predetermined angle great enough so that the spongy solids will not clog to any appreciable extent between the opposed faces on top and will clear when subjected to the impact of the cascading column at the bottom.
Claim 12
Dependent Claim
312 words
In a device for separating and dewatering the generally spongy solids from the liquid in sanitary sewage, food processing, meat packing and the like, including a cylindrical screen having a screening medium about its outer periphery made up of spaced circumferentially arranged, generally parallel bars surrounding a generally open interior, the medium being at least 11 inches in diameter so as to provide a substantial free fall of the liquid resulting in appreciable impact when the liquid hits the bottom area of the medium, means supporting the screening medium for rotation and means for rotating it, a headbox containing a liquid-solid medium to be separated and opening against the medium at a point above a plane through its axis, a solids discharge adjacent the outer surface of the screening medium and spaced from the headbox in the direction of its rotation, movement of the screening medium carrying the separated solids from the headbox toward the solids discharge with the liquid passing through the screening medium and falling freely in a cascading free column down to the bottom area of the screening medium, the bars that make up the screening medium each having a generally flat outer face which, as a group, make up a cylindrical, generally smooth exterior surface with limited openings between adjacent bars to effect maximum separation adjacent the headbox followed by transportation of the separated solids to the solids discharge, the bars having inwardly diverging sides which define downwardly opening separating slots at the top and upwardly opening liquid-collecting cleaning troughs at the bottom of the cascading column with the included angle between the opposed sides of adjacent bars being at a predetermined angle great enough so that the spongy solids will not clog to any appreciable extent between the opposed faces on top and will clear when subjected to the impact of the cascading column at the bottom.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-04-07 | 1978-10-07 | 1979-04-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-07 | 1982-10-07 | 1983-04-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-07 | 1986-10-07 | 1987-04-08 | $7700.00 | Window Closed / Lapsed |