Patent US4876013A successfully refreshed from Google Patents.
US4876013A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Small volume rotary filter
Assignee: Membrex Inc
•
Filing: 1988-02-26
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Granted: 1989-10-24
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Expires: 2008-02-26
Abstract
Abstract An improved method and apparatus for filtration includes an outer stationary body, an inner rotating body defining a gap with the outer body for receiving a fluid sample, the surface of one of the bodies defining the gap being a filter. The rotation of the inner body creates Taylor vortices which continuously displace occluded solute on the filter surface. The filter can be a membrane. In one embodiment the device may be used to filter very small volumes of fluid such as are handled in clinical and other laboratories.
Inventors
- 👤 Iosif Shmidt
- 👤 Mario Badiali
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 18:48
CPC Classifications
B; B01; B01D; B01D35/00; B01D35/06; B01D29/00; B01D29/11; B01D29/13; B01D29/23; B01D29/25; B01D33/00; B01D33/06; B01D33/073; B01D33/70; B01D33/76; B01D35/22; B01D63/00; B01D63/06; B01D63/16; B01D65/00; B01D65/08; B01D9/00; B01F; B01F27/00; B01F27/27; B01F27/272; B01F27/2722; B01F27/2723; B01D2201/00; B01D2201/28; B01D2201/285; B01D2201/287; B01D2315/00; B01D2315/02; B01D2317/00; B01D2317/08; B01D2321/00; B01D2321/20; B01D2321/2008; B01D2321/2016; B01D29/76; B01D29/86; B01D29/88; B01D29/90; B01D29/902; B01D33/58; B01D33/68; B01D33/72; B01F25/00; B01F2025/91; B01F2025/911; B01F27/80; Y; Y10; Y10T; Y10T436/00; Y10T436/25; Y10T436/25375; Y10T436/255
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
311 words
A rotary vertical filtration device for separating small volumes of liquid into permeate and concentrate portions, the concentrate not filtered by the end of separation being the retentate, said device having a very small minimum retentate volume and no bottom dynamic seal and comprising: (a) a rotor member having a top portion, an essentially cylindrical or conical outer wall, a vertical longitudinal central axis of rotation, and a bottom wall through which permeate cannot be removed; (b) a housing with an essentially cylindrical or conical having a top, a side, and a bottom defined by (i) a top housing member, (ii) an essentially cylindrical or conical housing inner wall larger in diameter than the rotor member, and (iii) a bottom housing member, the rotor member being rotatably connected to the housing and being within the cylindrical or conical cavity, the cavity having a vertical longitudinal axis substantially parallel to the longitudinal axis of the rotor member, the essentially cylindrical or conical housing inner wall corresponding to and being closely spaced from the corresponding portion of the cylindrical or conical outer wall of the rotor member to define an essentially cylindrical or conical narrow gap between said inner and outer walls; (c) a filter that allows permeate to pass through it mounted on the cylindrical or conical outer wall of the rotor member or on the cylindrical or conical inner wall of &:he housing, the filter having a filtration area whose lower extent is very close to the bottom housing member to minimize the minimum retentate volume of the cavity, which retentate cannot be filtered because that minimum volume is below the lower extent of the filtration area; (d) entry means to allow liquid to enter the gap; and (e) means to rotate the rotor member so that the calculated Taylor number for liquid in the gap is greater than about 40.
Claim 2
Dependent Claim
311 words
A rotary vertical filtration device for separating small volumes of liquid into permeate and concentrate portions, the concentrate not filtered by the end of separation being the retentate, said device having a very small minimum retentate volume and no bottom dynamic seal and comprising: (a) a rotor member having a top portion, an essentially cylindrical or conical outer wall, a vertical longitudinal central axis of rotation, and a bottom wall through which permeate cannot be removed; (b) a housing with an essentially cylindrical or conical having a top, a side, and a bottom defined by (i) a top housing member, (ii) an essentially cylindrical or conical housing inner wall larger in diameter than the rotor member, and (iii) a bottom housing member, the rotor member being rotatably connected to the housing and being within the cylindrical or conical cavity, the cavity having a vertical longitudinal axis substantially parallel to the longitudinal axis of the rotor member, the essentially cylindrical or conical housing inner wall corresponding to and being closely spaced from the corresponding portion of the cylindrical or conical outer wall of the rotor member to define an essentially cylindrical or conical narrow gap between said inner and outer walls; (c) a filter that allows permeate to pass through it mounted on the cylindrical or conical outer wall of the rotor member or on the cylindrical or conical inner wall of &:he housing, the filter having a filtration area whose lower extent is very close to the bottom housing member to minimize the minimum retentate volume of the cavity, which retentate cannot be filtered because that minimum volume is below the lower extent of the filtration area; (d) entry means to allow liquid to enter the gap; and (e) means to rotate the rotor member so that the calculated Taylor number for liquid in the gap is greater than about 40.
Claim 3
Dependent Claim
27 words
The rotary filtration device of claim 1 further comprising means to establish a pressure differential across the filter to aid the flow of permeate through the filter.
Claim 4
Dependent Claim
13 words
The rotary filtration device of claim 1 wherein the filter is a membrane.
Claim 5
Dependent Claim
27 words
The rotary filtration device of claim 1 further comprising means to withdraw permeate through the top portion of the rotor member during rotation of the rotor member.
Claim 6
Dependent Claim
26 words
The rotary filtration device of claim 1 wherein filter is mounted on the inner wall of the housing and there is no filter on the rotor.
Claim 7
Dependent Claim
322 words
A batch rotary vertical filtration device for separating small volumes of liquid into permeate and concentrate portions, the concentrate not filtered by the end of separation being the retentate, said device having a very small minimum retentate volume and no bottom dynamic seal and comprising: (a) a rotor member having a top portion, an essentially cylindrical or conical outer wall, a vertical longitudinal central axis of rotation, and a bottom wall through which permeate cannot be removed; (b) a housing with an essentially cylindrical or conical cavity having a top, a side, and a bottom defined by (i) a top housing member, (ii) an essentially cylindrical or conical housing inner wall larger in diameter than the rotor member, and (iii) a bottom housing member, the rotor member being rotatably connected to the housing and being within the cylindrical or conical cavity, the cavity having a vertical longitudinal axis substantially parallel to the longitudinal axis of the rotor member, the essentially cylindrical or conical housing inner wall corresponding to and being closely spaced from the corresponding portion of the cylindrical or conical outer wall of the rotor member to define an essentially cylindrical or conical narrow gap between said inner and outer walls; (c) a filter that allows permeate to pass through it mounted on the cylindrical or conical outer wall of the rotor member or on the cylindrical or conical inner wall of the housing, the filter having a filtration area whose lower extent is very close to the bottom housing member to minimize the minimum retentate volume of the cavity, which retentate cannot be filtered because that minimum volume is below the lower extent of the filtration area; (d) entry means to allow liquid to enter the gap; and (e) means to rotate the rotor member so that the calculated Taylor number for liquid in the gap is greater than about 40; wherein the permeate is recovered after rotation has stopped.
Claim 8
Dependent Claim
322 words
A batch rotary vertical filtration device for separating small volumes of liquid into permeate and concentrate portions, the concentrate not filtered by the end of separation being the retentate, said device having a very small minimum retentate volume and no bottom dynamic seal and comprising: (a) a rotor member having a top portion, an essentially cylindrical or conical outer wall, a vertical longitudinal central axis of rotation, and a bottom wall through which permeate cannot be removed; (b) a housing with an essentially cylindrical or conical cavity having a top, a side, and a bottom defined by (i) a top housing member, (ii) an essentially cylindrical or conical housing inner wall larger in diameter than the rotor member, and (iii) a bottom housing member, the rotor member being rotatably connected to the housing and being within the cylindrical or conical cavity, the cavity having a vertical longitudinal axis substantially parallel to the longitudinal axis of the rotor member, the essentially cylindrical or conical housing inner wall corresponding to and being closely spaced from the corresponding portion of the cylindrical or conical outer wall of the rotor member to define an essentially cylindrical or conical narrow gap between said inner and outer walls; (c) a filter that allows permeate to pass through it mounted on the cylindrical or conical outer wall of the rotor member or on the cylindrical or conical inner wall of the housing, the filter having a filtration area whose lower extent is very close to the bottom housing member to minimize the minimum retentate volume of the cavity, which retentate cannot be filtered because that minimum volume is below the lower extent of the filtration area; (d) entry means to allow liquid to enter the gap; and (e) means to rotate the rotor member so that the calculated Taylor number for liquid in the gap is greater than about 40; wherein the permeate is recovered after rotation has stopped.
Claim 9
Dependent Claim
28 words
The batch rotary filtration device of claim 6 further comprising means to establish a pressure differential across the filter to aid the flow of permeate through the filter.
Claim 10
Dependent Claim
14 words
The batch rotary filtration device of claim 6 wherein the filter is a membrane.
Claim 11
Dependent Claim
30 words
The batch rotary filtration device of claim 6 wherein the permeate is collected inside the rotor member and the rotor member is removable from the device for recovering the permeate.
Claim 12
Dependent Claim
28 words
The batch rotary filtration device of claim 6 wherein a filter is mounted on the inner wall of the housing and there is no filter on the rotor.
Claim 13
Dependent Claim
341 words
A process for separating small volumes of liquid into permeate and concentrated portions, the concentrate not filtered by the end of separation being the retentate, said process comprising: (a) providing a vertical rotary filtration device having a very small minimum retentate volume and no bottom dynamic seal and comprising: (i) a rotor member having a top portion, an essentially cylindrical or conical outer wall, a vertical longitudinal central axis of rotation, and a bottom wall through which permeate cannot be removed; (ii) a housing with an essentially cylindrical or conical cavity having a top, a side, and a bottom defined by (A) a top housing member, (B) an essentially cylindrical or conical housing inner wall larger in diameter than the rotor member, and (C) a bottom housing member, the rotor member being rotatably connected to the housing and being within the cylindrical or conical cavity, the cavity having a vertical longitudinal axis substantially parallel to the longitudinal axis of the rotor member, the essentially cylindrical or conical housing inner wall corresponding to and being closely spaced from the corresponding portion of the cylindrical or conical outer wall of the rotor member to define an essentially cylindrical or conical narrow gap between said inner and outer walls; (iii) a filter that allows permeate to pass through it mounted on the cylindrical or conical outer wall of the rotor member or on the cylindrical or conical inner wall of the housing, the filter having a filtration area whose lower extent is very close to the bottom housing member to minimize the minimum retentate volume of the cavity, which retentate cannot be filtered because that minimum volume is below the lower extent of the filtration area; (iv) entry means to allow liquid to enter &:he gap; and (v) means to rotate the rotor member so that the calculated Taylor number for liquid in the gap is greater than about 40; (b) placing liquid to be filtered in the gap; and (c) rotating the rotor member to separate the liquid into permeate and concentrate portions.
Claim 14
Dependent Claim
341 words
A process for separating small volumes of liquid into permeate and concentrated portions, the concentrate not filtered by the end of separation being the retentate, said process comprising: (a) providing a vertical rotary filtration device having a very small minimum retentate volume and no bottom dynamic seal and comprising: (i) a rotor member having a top portion, an essentially cylindrical or conical outer wall, a vertical longitudinal central axis of rotation, and a bottom wall through which permeate cannot be removed; (ii) a housing with an essentially cylindrical or conical cavity having a top, a side, and a bottom defined by (A) a top housing member, (B) an essentially cylindrical or conical housing inner wall larger in diameter than the rotor member, and (C) a bottom housing member, the rotor member being rotatably connected to the housing and being within the cylindrical or conical cavity, the cavity having a vertical longitudinal axis substantially parallel to the longitudinal axis of the rotor member, the essentially cylindrical or conical housing inner wall corresponding to and being closely spaced from the corresponding portion of the cylindrical or conical outer wall of the rotor member to define an essentially cylindrical or conical narrow gap between said inner and outer walls; (iii) a filter that allows permeate to pass through it mounted on the cylindrical or conical outer wall of the rotor member or on the cylindrical or conical inner wall of the housing, the filter having a filtration area whose lower extent is very close to the bottom housing member to minimize the minimum retentate volume of the cavity, which retentate cannot be filtered because that minimum volume is below the lower extent of the filtration area; (iv) entry means to allow liquid to enter &:he gap; and (v) means to rotate the rotor member so that the calculated Taylor number for liquid in the gap is greater than about 40; (b) placing liquid to be filtered in the gap; and (c) rotating the rotor member to separate the liquid into permeate and concentrate portions.
Claim 15
Dependent Claim
36 words
The process of claim 11 wherein the device has means to withdraw permeate from the device during rotation of the rotor member and the process further comprises withdrawing the permeate during rotation of the rotor member.
Claim 16
Dependent Claim
28 words
The process of claim 11 wherein separation is continued until the volume of retentate remaining in the cavity is equal to the minimum retentate volume of the cavity.
Claim 17
Dependent Claim
47 words
The process of claim 11 wherein the device further comprises means to establish a pressure differential across the filter to aid the flow of permeate through the filter and the process further comprises establishing such a pressure differential to aid the flow of permeate through the filter.
Claim 18
Dependent Claim
35 words
The process of claim 14 the device has means to withdraw permeate from the device during rotation of the rotor member and the process further comprises withdrawing the permeate during rotation of the rotor member.
Claim 19
Dependent Claim
28 words
The process of claim 14 wherein separation is continued until the volume of retentate remaining in the cavity is equal to the minimum retentate volume of the cavity.
Claim 20
Dependent Claim
17 words
The process of claim 11 further comprising withdrawing the permeate after rotation of the rotor has stopped.
Claim 21
Dependent Claim
29 words
The process of claim 11 wherein the device has a filter mounted on the inner wall of the housing and the process further comprises withdrawing permeate from the device.
Claim 22
Dependent Claim
31 words
The process of claim 11 wherein the device has a filter mounted on the outer wall of the rotor member and the process further comprises collecting permeate inside the rotor member.
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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) | 1992-10-23 | 1993-04-24 | 1993-10-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-10-23 | 1997-04-24 | 1997-10-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-10-23 | 2001-04-24 | 2001-10-24 | $7700.00 | Window Closed / Lapsed |