US3872005A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Skimming apparatus for clarification tanks
Assignee: FMC Corp
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Filing: 1972-10-18
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Granted: 1975-03-18
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Expires: 1992-10-18
Abstract
Abstract This invention relates to a skimming apparatus for use in a liquid clarification tank which has a plurality of longitudinally open topped extending weir boxes that define the outlet for receiving clarified liquid. The skimming apparatus consists of a reciprocating bridge supporting an elongated blade that extends transversely of the tank and has recesses aligned with the longitudinally extending weir boxes with power means between the bridge and the blade for raising and lowering the blade. The power means define a first skimming position for the blade while the blade is in the weir box area of the tank where the lower edge of the blade is below the liquid level while the bases of the recesses are above the weir boxes and a second skimming position wherein the bases of the recesses and the lower edge of the blade are located below the liquid level. In one embodiment, the power means includes a fluid ram that has hydraulic fluid supplied thereto from a valve with switch means actuating the valve automatically when the bridge reaches a certain position and automatically moves the blade from the first skimming position to the second skimming position, as the bridge leaves the weir box area of the tank. In an alternate embodiment, the power means includes a drum on the bridge with cable means on the drum and connected to the blades. A reversible drive motor is actuated by switch means for reeling and unreeling the cable means on the drum and raising and lowering the blade.
Inventors
- 👤 Jeffrey A Baker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 12:09
CPC Classifications
B; B01; B01D; B01D21/00; B01D21/10; B01D21/12; B01D21/18; B01D21/24; B01D21/2433
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
387 words
In a liquid clarification apparatus including a tank having an inlet for supplying fluid with entrained solids and an outlet for receiving clarified liquid, said outlet including a plurality of transversely spaced longitudinally extending weir boxes, said weir boxes each having a bottom wall and side walls having upper edges defining the liquid level for said tank; baffle structure surrounding each weir box, said baffle structure having upper and lower edges respectively located above and below said upper edges; a traveling bridge above said tank; drive means for reciprocating said bridge between extreme positions parallel to said longitudinally extending weir boxes; and skimming means depending from said bridge for removing scum from the surface of said liquid, said skimming means including an elongated blade extending transversely of said tank, said blade having recesses aligned with said weir boxes and extending from the lower edge of said blade, said recesses allowing the lower edge of the blade to be below the liquid level while the bridge is in the weir box area of the tank; power means for raising and lowering said blade on said bridge, said power means defining a first skimming position for said blade where the lower edge of the blade is located below the liquid level and the bases of the recesses are above said upper edges of said side walls when said bridge is traveling in one direction in the weir box area of the tank, said power means defining a second skimming position for said blade wherein the recesses and the lower edge of said blade are located below said upper edges of said side walls while the blade is located in the area of the tank between the weir boxes and the inlet end, said power means defining a third inoperative position for said blade where the lower edge of said blade is located above said upper edges of said side wall; said power means including fluid rams between said blade and said bridge, valve means connected to said fluid rams; switch means cooperating with said valve means and carried by said bridge; and actuating means for actuating said switch means when said bridge is at opposite ends of said tank and at inner ends of said weir boxes to operate said valve means and move said blade between said positions.
Claim 2
Dependent Claim
387 words
In a liquid clarification apparatus including a tank having an inlet for supplying fluid with entrained solids and an outlet for receiving clarified liquid, said outlet including a plurality of transversely spaced longitudinally extending weir boxes, said weir boxes each having a bottom wall and side walls having upper edges defining the liquid level for said tank; baffle structure surrounding each weir box, said baffle structure having upper and lower edges respectively located above and below said upper edges; a traveling bridge above said tank; drive means for reciprocating said bridge between extreme positions parallel to said longitudinally extending weir boxes; and skimming means depending from said bridge for removing scum from the surface of said liquid, said skimming means including an elongated blade extending transversely of said tank, said blade having recesses aligned with said weir boxes and extending from the lower edge of said blade, said recesses allowing the lower edge of the blade to be below the liquid level while the bridge is in the weir box area of the tank; power means for raising and lowering said blade on said bridge, said power means defining a first skimming position for said blade where the lower edge of the blade is located below the liquid level and the bases of the recesses are above said upper edges of said side walls when said bridge is traveling in one direction in the weir box area of the tank, said power means defining a second skimming position for said blade wherein the recesses and the lower edge of said blade are located below said upper edges of said side walls while the blade is located in the area of the tank between the weir boxes and the inlet end, said power means defining a third inoperative position for said blade where the lower edge of said blade is located above said upper edges of said side wall; said power means including fluid rams between said blade and said bridge, valve means connected to said fluid rams; switch means cooperating with said valve means and carried by said bridge; and actuating means for actuating said switch means when said bridge is at opposite ends of said tank and at inner ends of said weir boxes to operate said valve means and move said blade between said positions.
Claim 3
Dependent Claim
400 words
In a liquid clarification apparatus including a tank having an inlet for supplying fluid with entrained solids and an outlet for receiving clarified liquid, said outlet including a plurality of transversely spaced longitudinally extending weir boxes, said weir boxes each having a bottom wall and side walls having upper edges defining the liquid level for said tank; baffle structure surrounding each weir box, said baffle structure having upper and lower edges respectively located above and below said upper edges; a traveling bridge above said tank; drive means for reciprocating said bridge between extreme positions parallel to said longitudinally extending weir boxes; and skimming means depending from said bridge for removing scum from the surface of said liquid, said skimming means including an elongated blade extending transversely of said tank, said blade having recesses aligned with said weir boxes and extending from the lower edge of said blade, said recesses allowing the lower edge of the blade to be below the liquid level while the bridge is in the weir box area of the tank; power means for raising and lowering said blade on said bridge, said power means defining a first skimming position for said blade where the lower edge of the blade is located below the liquid level and the bases of the recesses are above said upper edges of said side walls when said bridge is traveling in one direction in the weir box area of the tank, said power means defining a second skimming position for said blade wherein the recesses and the lower edge of said blade are located below said upper edges of said side walls while the blade is located in the area of the tank between the weir boxes and the inlet end, said power means defining a third inoperative position for said blade where the lower edge of said blade is located above said upper edges of said side wall; said power means including a shaft rotatable on said bridge, drum means fixed to said shaft, cable means between said drum means and said blade, reversible drive means connected to said shaft; switch means cooperating with said drive means and carried by said bridge; and actuating means for actuating said switch means when said bridge is at opposite ends of said tank and at inner ends of said weir boxes to operate said drive means and move said blade between said positions.
Claim 4
Dependent Claim
400 words
In a liquid clarification apparatus including a tank having an inlet for supplying fluid with entrained solids and an outlet for receiving clarified liquid, said outlet including a plurality of transversely spaced longitudinally extending weir boxes, said weir boxes each having a bottom wall and side walls having upper edges defining the liquid level for said tank; baffle structure surrounding each weir box, said baffle structure having upper and lower edges respectively located above and below said upper edges; a traveling bridge above said tank; drive means for reciprocating said bridge between extreme positions parallel to said longitudinally extending weir boxes; and skimming means depending from said bridge for removing scum from the surface of said liquid, said skimming means including an elongated blade extending transversely of said tank, said blade having recesses aligned with said weir boxes and extending from the lower edge of said blade, said recesses allowing the lower edge of the blade to be below the liquid level while the bridge is in the weir box area of the tank; power means for raising and lowering said blade on said bridge, said power means defining a first skimming position for said blade where the lower edge of the blade is located below the liquid level and the bases of the recesses are above said upper edges of said side walls when said bridge is traveling in one direction in the weir box area of the tank, said power means defining a second skimming position for said blade wherein the recesses and the lower edge of said blade are located below said upper edges of said side walls while the blade is located in the area of the tank between the weir boxes and the inlet end, said power means defining a third inoperative position for said blade where the lower edge of said blade is located above said upper edges of said side wall; said power means including a shaft rotatable on said bridge, drum means fixed to said shaft, cable means between said drum means and said blade, reversible drive means connected to said shaft; switch means cooperating with said drive means and carried by said bridge; and actuating means for actuating said switch means when said bridge is at opposite ends of said tank and at inner ends of said weir boxes to operate said drive means and move said blade between said positions.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-17 | 1978-09-16 | 1979-03-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-17 | 1982-09-16 | 1983-03-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-17 | 1986-09-16 | 1987-03-18 | $7700.00 | Window Closed / Lapsed |