Patent Application
20220088512
In order to achieve filtration performance targets, it may be necessary to use large and/or multiple filtration devices, or use filter devices that have to be replaced more often due to an increase in pressure drop resulting from insufficient filtration area. Either alternative can result in increased cost.
Thus, there is a need for improved filters. The present invention provides for ameliorating at least some of the disadvantages of the prior art. These and other advantages of the present invention will be apparent from the description as set forth below.
An aspect of the invention provides a filter arrangement comprising a plurality of filters in a radial arrangement, each filter comprising a plurality of filter arms, the plurality of filter arms comprising at least: a first filter arm comprising a first hollow tube having a porous side wall, the first hollow tube having an open first end and an open second end, and a first tube inner fluid channel having an inner diameter; and, a second filter arm comprising a second hollow tube having a porous side wall, the second hollow tube having an open first end and an open second end, and a second tube inner fluid channel having an inner diameter; each filter further comprising: a first tube connector, comprising a first hollow body having a porous side wall and first hollow body inner diameter, connected to, and in fluid communication with, the first and second hollow tubes, wherein the first hollow body inner diameter is greater than the tube inner fluid channel inner diameters; and, a second tube connector, comprising a second hollow body having a porous side wall and a second hollow body inner diameter, connected to, and in fluid communication with, the first hollow body, wherein the second hollow body inner diameter is greater than the first hollow body inner diameter.
In a preferred aspect of the filter arrangement, the plurality of filters are radially arranged between a central hollow hub and an outer cage, the central hollow hub including a central opening and a plurality of hub channels in fluid communication with the second hollow bodies, the outer cage including a plurality of retentate fluid flow ports in fluid communication with the first ends of the hollow tubes; and wherein spacing between the porous side walls of the hollow tubes provides permeate fluid flow paths.
Another aspect of the invention provides a filter arrangement comprising a plurality of curved filters in a radial arrangement, each filter comprising a plurality of curved filter arms, the plurality of curved filter arms comprising at least: a curved first filter arm comprising a curved first hollow tube having a porous side wall, the curved first hollow tube having an open first end and an open second end, and a curved first tube inner fluid channel having an inner diameter; and, a curved second filter arm comprising a curved second hollow tube having a porous side wall, the curved second hollow tube having an open first end and an open second end, and a curved second tube inner fluid channel having an inner diameter; each curved filter further comprising: a curved first tube connector, comprising a first hollow body having a porous side wall and first hollow body inner diameter, connected to, and in fluid communication with, the curved first and second hollow tubes, wherein the first hollow body inner diameter is greater than the tube inner fluid channel inner diameters; and, a curved second tube connector, comprising a second hollow body having a porous side wall and a second hollow body inner diameter, connected to, and in fluid communication with, the first hollow body, wherein the second hollow body inner diameter is greater than the first hollow body inner diameter.
In a preferred aspect of the filter arrangement, the plurality of curved filters are radially arranged between a central hollow hub and an outer cage, the central hollow hub including a central opening and a plurality of hub channels in fluid communication with the curved second hollow bodies, the outer cage including a plurality of retentate fluid flow ports in fluid communication with the first ends of the curved hollow tubes; and wherein spacing between the porous side walls of the curved hollow tubes provides permeate fluid flow paths.
In other aspects, filter devices, and methods of cross-flow filtration using the filter devices are provided, the filter devices each comprising filter housings having an inlet, a permeate outlet, and a retentate outlet, defining a permeate fluid flow path between the inlet and the permeate outlet, and a retentate fluid flow path between the inlet and the retentate outlet, with aspects of one or more filter arrangements arranged in the housings across the permeate fluid flow paths.
An aspect of the invention provides a filter arrangement comprising a plurality of filters in a radial arrangement, each filter comprising a plurality of filter arms, the plurality of filter arms comprising at least: a first filter arm comprising a first hollow tube having a porous side wall, the first hollow tube having an open first end and an open second end, and a first tube inner fluid channel having an inner diameter; and, a second filter arm comprising a second hollow tube having a porous side wall, the second hollow tube having an open first end and an open second end, and a second tube inner fluid channel having an inner diameter; each filter further comprising: a first tube connector, comprising a first hollow body having a porous side wall and first hollow body inner diameter, connected to, and in fluid communication with, the first and second hollow tubes, wherein the first hollow body inner diameter is greater than the tube inner fluid channel inner diameters; and, a second tube connector, comprising a second hollow body having a porous side wall and a second hollow body inner diameter, connected to, and in fluid communication with, the first hollow body, wherein the second hollow body inner diameter is greater than the first hollow body inner diameter.
In a preferred aspect of the filter arrangement, the plurality of filters are radially arranged between a central hollow hub and an outer cage, the central hollow hub including a central opening and a plurality of hub channels in fluid communication with the second hollow bodies, the outer cage including a plurality of retentate fluid flow ports in fluid communication with the first ends of the hollow tubes; and wherein spacing between the porous side walls of the hollow tubes provides permeate fluid flow paths.
Another aspect of the invention provides a filter arrangement comprising a plurality of curved filters in a radial arrangement, each filter comprising a plurality of curved filter arms, the plurality of curved filter arms comprising at least: a curved first filter arm comprising a curved first hollow tube having a porous side wall, the curved first hollow tube having an open first end and an open second end, and a curved first tube inner fluid channel having an inner diameter; and, a curved second filter arm comprising a curved second hollow tube having a porous side wall, the curved second hollow tube having an open first end and an open second end, and a curved second tube inner fluid channel having an inner diameter; each curved filter further comprising: a curved first tube connector, comprising a first hollow body having a porous side wall and first hollow body inner diameter, connected to, and in fluid communication with, the curved first and second hollow tubes, wherein the first hollow body inner diameter is greater than the tube inner fluid channel inner diameters; and, a curved second tube connector, comprising a second hollow body having a porous side wall and a second hollow body inner diameter, connected to, and in fluid communication with, the first hollow body, wherein the second hollow body inner diameter is greater than the first hollow body inner diameter.
Aspects of the filters in the filter arrangements can include filter arms including any number of hollow tubes (including straight hollow tubes, or curved hollow tubes), and, if desired, any number of first tube connectors and second tube connectors (including straight, or curved, first and second tube connectors).
Aspects of filters in the filter arrangements can have any number of sets of a plurality of filter arms, and each set can communicate with a separate first tube connector, and a plurality of separate first tube connectors can communicate with a common second tube connector.
In a preferred aspect of the filter arrangement, the plurality of curved filters are radially arranged between a central hollow hub and an outer cage, the central hollow hub including a central opening and a plurality of hub channels in fluid communication with the curved second hollow bodies, the outer cage including a plurality of retentate fluid flow ports in fluid communication with the first ends of the curved hollow tubes; and wherein spacing between the porous side walls of the curved hollow tubes provides permeate fluid flow paths.
In other aspects, filter devices, and methods of cross-flow filtration using the filter devices are provided, the filter devices each comprising filter housings having an inlet, a permeate outlet, and a retentate outlet, defining a permeate fluid flow path between the inlet and the permeate outlet, and a retentate fluid flow path between the inlet and the retentate outlet, with aspects of one or more filter arrangements (preferably, two or more filter arrangements) arranged in the housings across the permeate fluid flow paths.
Each of the components of the invention will now be described in more detail below, wherein like components have like reference numbers. The illustrated aspects of filter devices are arranged for inside-out filter flow.
As illustrated in
The relationships between the lengths of the filter arms, first connectors, and second connectors, are not limited to those as illustrated, the various lengths can be all equal, or two can be equal, or, for example, L1A<L2A>L3A, etc. Additionally, or alternatively, in those aspects including a plurality of filters, the relationships between the lengths of the filter arms, first connectors, and second connectors, can be different for different filters in the same filter device.
Typically, as illustrated in
In some aspects, curved filters can provide more filter area with the same outside diameter than straight filters. In the aspect illustrated in
As illustrated in
Similar to the discussion with respect to, for example, the aspect illustrated in
One or more aspects of filter arrangements are typically disposed in a housing comprising an inlet, a permeate outlet, and a retentate outlet, defining a permeate fluid flow path between the inlet and the permeate outlet, and a retentate fluid flow path between the inlet and the retentate outlet, with aspects of one or more filter arrangements arranged in the housing across the permeate fluid flow path.
If desired, aspects of the invention can be utilized in closed and sterile systems. As used herein, the term “closed” refers to a system that allows the collection and processing (including filtration, and, if desired, the manipulation, e.g., separation of portions, separation into components, storage, and preservation) of fluid, without exposing the contents of the system to the environment in which it is being used. A closed system can be as originally made, or result from the connection of system components of sanitary fittings including sterile docking devices.
The side walls of the hollow tubes and the first tube connectors (and in some aspects, the second tube connectors) can have any suitable pore structure, e.g., a pore size (for example, as evidenced by bubble point, or by KL as described in, for example, U.S. Pat. No. 4,340,479, or evidenced by capillary condensation flow porometry), a mean flow pore (MFP) size (e.g., when characterized using a porometer, for example, a Porvair Porometer (Porvair plc, Norfolk, UK), or a porometer available under the trademark POROLUX (Porometer.com; Belgium)), a pore rating, a pore diameter (e.g., when characterized using the modified OSU F2 test as described in, for example, U.S. Pat. No. 4,925,572), or removal rating media. The pore structure used depends on the size of the particles to be utilized, the composition of the fluid to be treated, and the desired effluent level of the treated fluid. In those aspects wherein the walls of the first and/or second tube connectors are porous (e.g., in some aspects wherein the hollow tubes and tube connectors are made from the same material), the pore structure of the tube connector walls is no greater than the pore structure of the walls of the hollow tubes.
A filter can have any desired critical wetting surface tension (CWST, as defined in, for example, U.S. Pat. No. 4,925,572). The CWST can be selected as is known in the art, e.g., as additionally disclosed in, for example, U.S. Pat. Nos. 5,152,905, 5,443,743, 5,472,621, and 6,074,869. Typically, the filter element has a CWST of at least about 17 dynes/cm (about 17×10−5 N/cm), for example, a CWST in the range of from about 17 dynes/cm to about 90 dynes/cm (about 17×10−5 N/cm to about 90×10−5 N/cm), more typically in the range of about 50 dynes/cm to about 60 dynes/cm (about 50×10−5 N/cm to about 60×10−5 N/cm).
The surface characteristics of a filter can be modified (e.g., to affect the CWST, to include a surface charge, e.g., a positive or negative charge, and/or to alter the polarity or hydrophilicity of the surface) by wet or dry oxidation, by coating or depositing a polymer on the surface, or by a grafting reaction.
Any aspects of the filters and/or filter arrangements can include additional elements, layers, or components, that can have different structures and/or functions, e.g., at least one of any one or more of the following: prefiltration, support, drainage, spacing and cushioning. Illustratively, the filter can also include at least one additional element such as a mesh and/or a screen.
In accordance with aspects of the invention, filters and filter arrangements can have a variety of configurations, including planar, pleated, and hollow cylindrical.
Filters, and filter arrangements (including filter arms and tube connectors) and housings according to aspects of the invention are preferably monolithic, and preferably manufactured via additive manufacturing (sometimes referred to as “additive layer manufacturing” or “3D printing”). They are typically formed by repeated depositions of a metal powder bound together with an activatable binder (e.g., binder jetting, sometimes referred to as “drop on powder”), typically followed by agglomerating the powder, e.g., by sintering. Other suitable methods include extrusion (e.g., paste extrusion, fused filament fabrication and fused deposition modelling) and light polymerization (e.g., stereolithography apparatus (SLA), and digital light processing (DLP)).
Filters, filter arms, and filter arrangements and housings can be manufactured together via additive manufacturing in a continuous operation at substantially the same time.
Any suitable additive manufacturing equipment can be used, and a variety of production 3D printers are suitable and commercially available.
All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.
The use of the terms “a” and “an” and “the” and “at least one” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The use of the term “at least one” followed by a list of one or more items (for example, “at least one of A and B”) is to be construed to mean one item selected from the listed items (A or B) or any combination of two or more of the listed items (A and B), unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.
Preferred aspects of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred aspects may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.
