US4060175A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Diaphragm tank cover
Assignee: Fiberglass Specialty Co Inc
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Filing: 1976-07-02
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Granted: 1977-11-29
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Expires: 1996-07-02
Abstract
Abstract A digester tank assembly for use in digester systems for anaerobic digestion of waste water sludge comprising a tank having a fixed exterior cover, and a diaphragm member mounted in the tank dividing the tank into upper and lower compartments, said diaphragm member being positioned above the normal sludge level and being movable relative to the sludge level to provide for regulation of gas pressure on the interior of the digestion tank and to allow for substantial variations in gas storage volume at generally uniform pressures. The diaphragm member is connected to a sliding stack that is guided with respect to the fixed cover so that the stack will be allowed to move with the diaphragm as the diaphragm position varies in accordance with the gas storage volume. The diaphragm carries a flowable ballast material that will shift as the diaphragm raises and lowers and which can be varied in volume to maintain the desired pressure on the inside of the digester tank.
Inventors
- 👤 John R. Rysgaard, Sr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 23:10
CPC Classifications
C; C02; C02F; C02F3/00; C02F3/28
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
205 words
In a tank for anerobic digestion of sludge including a wall forming a container for holding sludge and a fixed outer cover mounted over said tank, the improvement comprising a flexible diaphragm sealingly attached to said wall and overlying said tank below said cover and above sludge in the tank to form a gas tight chamber below the diaphragm, said diaphragm being supported at its periphery on said wall and spaced above sludge in the tank, a vent stack for regulating pressure attached to said diaphragm in the center portions thereof and opening directly to the chamber below the diaphragm and, passing through said fixed cover, means to slidably guide said vent stack with respect to said cover to guide said diaphragm and permit said diaphragm and stack to move between upper and lower positions spaced at different heights above said sludge as a function of gas volume under said diaphragm formed by said sludge, and to maintain a substantially constant pressure through out movement of said diaphragm between its upper and lower positions, and weight means on said diaphragm comprising a ballast material on the upper surface of said diaphragm which is movable with said diaphragm as the gas volume changes below said diaphragm.
Claim 2
Dependent Claim
205 words
In a tank for anerobic digestion of sludge including a wall forming a container for holding sludge and a fixed outer cover mounted over said tank, the improvement comprising a flexible diaphragm sealingly attached to said wall and overlying said tank below said cover and above sludge in the tank to form a gas tight chamber below the diaphragm, said diaphragm being supported at its periphery on said wall and spaced above sludge in the tank, a vent stack for regulating pressure attached to said diaphragm in the center portions thereof and opening directly to the chamber below the diaphragm and, passing through said fixed cover, means to slidably guide said vent stack with respect to said cover to guide said diaphragm and permit said diaphragm and stack to move between upper and lower positions spaced at different heights above said sludge as a function of gas volume under said diaphragm formed by said sludge, and to maintain a substantially constant pressure through out movement of said diaphragm between its upper and lower positions, and weight means on said diaphragm comprising a ballast material on the upper surface of said diaphragm which is movable with said diaphragm as the gas volume changes below said diaphragm.
Claim 3
Dependent Claim
59 words
The combination of claim 1 wherein said means to slidably guide said vent stack comprises an outer housing mounted on said cover and surrounding said vent stack, roller means mounted on the housing and engaging said vent stack, and a relief valve opening from said vent stack to atmosphere to control the maximum pressure in said gas tight chamber.
Claim 4
Dependent Claim
40 words
The combination as specified in claim 1 wherein said ballast material comprises a particulate material that changes in peripheral cross section as said diaphragm moves between its upper and lower positions, but does not flow freely circumferentially on said diaphragm.
Claim 5
Dependent Claim
21 words
The tank of claim 1 wherein said ballast material comprises particulate material that does not flow freely circumferentially on said diaphragm.
Claim 6
Dependent Claim
76 words
The tank of claim 1 wherein said wall is substantially cylindrical and has an upper edge surface, and said diaphragm is supported on said upper edge, means to seal said diaphragm to said upper edge comprising a layer of mastic between the diaphragm and upper edge, a ring member overlying said diaphragm at said upper edge, and means to clamp said ring toward said upper edge and force said diaphragm against said mastic and upper edge.
Claim 7
Dependent Claim
32 words
The tank of claim 1 and means to seal edges of said vent stack to said diaphragm including a flange on said stack and a ring clamping said diaphragm against said flange.
Claim 8
Dependent Claim
94 words
The tank of claim 6 wherein said diaphragm is made in sections of flexible material, said sections being joined to adjacent sections along junction edges, sealing means to seal said junction edges including separate pieces of material that overlie a junction edge on the top and bottom of adjacent diaphragm sections, adhesive means sealing the pieces of material to the diaphragm, and stitching on both sides of said junction edges extending through both pieces of material at that junction edge and through the adjacent diaphragm sections to secure the pieces of material in position.
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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) | 1980-11-28 | 1981-05-30 | 1981-11-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-11-28 | 1985-05-30 | 1985-11-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-11-28 | 1989-05-30 | 1989-11-29 | $7700.00 | Window Closed / Lapsed |