Patent Description:
Membrane contactors are devices used to, among other things, degas liquids. For example, membrane contactors may be used to degas the ink used in, for example, industrial printers.

Hollow fiber membrane contactors typically operate on a diffusion principle. Such membrane contactors typically have a shell side and a lumen (or tube) side, and these sides are separated with a membrane, for example, a microporous membrane. In operation, the gas entrained liquid is introduced into one side of the contactor, while vacuum or a combination of vacuum and swept gas is passed through the other side. As the liquid passes through its side, the gas diffuses across the membrane into the other side.

Two small membrane contactors are illustrated in <FIG> (both prior art). Such Liqui-Cel ® brand contactors are commercially available from the Membrana-Charlotte Division of Celgard, LLC of Charlotte, NC. While these are excellent small membrane contactors, there is still a need for improved small membrane contactors or improved production methods for such contactors for at least certain applications.

<CIT> describes a membrane contactor that includes a housing, a stack of membrane mats, and a cap. The housing has a closed end and an open end. The closed end includes an outlet port. The cap is united to the open end and includes an inlet port.

<CIT> discloses a hollow fiber membrane contactor. The hollow fiber membrane contactor includes a cartridge, a shell, a first end cap, and a second end cap. The shell, which is adapted for enclosing the cartridge, has two ends and an opening. The cartridge further includes a perforated center tube, a hollow fiber fabric, a first tube sheet, a second tube sheet, and a plug. The first end cap has an opening therethrough, which is in communication with hollow fiber lumens via said first headspace. The second end cap has an opening, and it is in communication with the center tube.

<CIT> discloses a process for sealing a hollow fiber membrane separation module into a case. The hollow fiber membrane separation module is formed from a plurality of hollow fibers arranged in a bundle surrounding a core and having tube sheets surrounding each end of the bundles which bind the hollow fibers together. The disclosed process simultaneous with such sealing creates first and second spaces overlying the ends of the plurality of hollow fibers.

<CIT> describes a hollow fiber cartridge including a stack of hollow fiber mats. The stack has a major axis and two end faces Each mat is substantially perpendicular to the axis. An end cap is united to each end face.

<CIT> discloses a hollow fiber membrane contactor, and method of making same. The hollow fiber membrane contactor includes a shell having an internal bonding surface, an interlocking geometry ring being provided on said internal bonding surface; a unitized structure; a potting material joining said unitized structure to said shell at said interlocking geometry ring thereby forming an interlocking seal therebetween; and end caps. The end caps are adjoined to lateral ends of said shell.

<CIT> describes a gas-permeable membrane apparatus which comprises a chamber having an inlet-end connector portion and an outlet-end connector portion; a tube bundle housed within said chamber; a cylindrical coupling insertable into each of the connector portions of said chamber, having at a first end thereof a line connector portion for connecting a liquid inlet line or outlet line and having at a second end thereof a tube bundle connector portion for connecting said tube bundle; and a fastener member for threadably fastening each of said cylindrical couplings.

<CIT> describes a hollow fiber membrane contactor which includes a perforated center tube, a first mat comprising a first hollow fiber membrane, a second mat comprising a second hollow fiber membrane, a first tube sheet, a second tube sheet, a shell, and end caps. The shell surrounds the first and second mats, and it is sealed to the tube sheets. The end caps are affixed to the shell thereby defining headspaces between the tube sheets and the end caps.

The present invention concerns a membrane contactor and a method of making the membrane contactor as defined in the attached claims.

With reference again to the two small membrane contactors illustrated in <FIG> (both prior art), while these are excellent small membrane contactors, improvements in their construction and/or manufacture could drive down cost, enhance performance for certain applications, or both. <FIG> shows the 1x3 contactor; it requires two welds, W<NUM> and W<NUM> to seal the cap to the body and the membrane cartridge. <FIG> shows the 2x6 contactor; it has two caps C<NUM> and C<NUM>.

In at least one embodiment, a new or improved membrane contactor includes: a cap has an internally beveled surface and a cap port; a cup body has an externally beveled surface in sealing engagement with the internally beveled surface and a side port on a side of the cup body and an end port located on an end of the cup body; and a membrane cartridge is located within the cup body, is sealed to an open end of the cup body, and is in sealed fluid communication with the end port. Such an inventive contactor may be made by a method of making a membrane contactor includes the steps of: sealingly mating a perforated center of a membrane contactor with the end port of a cup body; sealingly joining an end of the membrane cartridge adjacent an open end of the cup body; and sealingly joining a beveled surface of the cap to a beveled external surface of the cup body.

For the purpose of illustrating the invention, there is shown in the drawings prior contactors and a form that is presently preferred; it being understood, however, that this invention is not limited to the precise arrangements and instrumentalities shown in <FIG>.

Referring to <FIG>, there is shown an embodiment of the inventive membrane contactor <NUM>. Contactor <NUM> generally includes a cap <NUM>, a cup body <NUM>, and membrane cartridge <NUM>. The membrane cartridge <NUM> may be located within the cup body <NUM>.

The cap <NUM> and cup body <NUM> are sealingly joined by joint <NUM> along joining surfaces <NUM>' and <NUM>". Surface <NUM>' may be an internally facing joining surface located on cap <NUM>, and surface <NUM>" may be an externally facing joining surface located on cup body <NUM>. The joint <NUM> is illustrated as a scarf joint (i.e., surfaces <NUM>' and <NUM>" are beveled), but joint <NUM> may be a shear joint (i.e., surfaces <NUM>' and <NUM>" are parallel to the axis of the contactor <NUM>), or a butt joint or any other combination of joint designs. Hereinafter, the contactor <NUM> will be illustrated with the scarf joint, but the shear joint may be used in place thereof.

Cap <NUM> may be generally cup shaped (e.g., circular cross-section) with an open end <NUM> and a closed end <NUM>, see <FIG>. Cap <NUM> may also include an internally beveled surface <NUM>', a shoulder <NUM>, a skirt <NUM>, a headspace <NUM>, and a cap port <NUM> with an opening <NUM> therethrough. Cap port <NUM> may be a nipple extending away from cap <NUM>. Beveled surface <NUM>' may have a shallow angle, for example <<NUM>°, or <NUM>°-<NUM>°. Skirt <NUM> extends beyond joint <NUM>, thereby concealing joint <NUM>. Nipple is a sealable fitting, for example - a Luer (or medical) fitting, NPT, straight tube, compression, quick-connect, or any other suitable fitting.

Cup body <NUM> may be generally cup shaped (e.g., circular cross-section) with an open end <NUM> and a closed end <NUM>, see <FIG>. Cup body <NUM> may also include an externally beveled surface <NUM>", a shoulder <NUM>, a side port <NUM> with an opening <NUM> therethrough, and end port <NUM> with an opening <NUM> therethrough. Beveled surface <NUM>" may complement the angle of beveled surface <NUM>'. Side port <NUM> may be a nipple <NUM> extending away from the cup body <NUM>. End port <NUM> may include a nipple extending away from the cup body <NUM>. End port <NUM> also includes an inwardly extending nipple <NUM> with a mating external surface <NUM>. Mating external surface <NUM> may be beveled. Mating external surface <NUM> may have a shallow angle, for example <<NUM>°, or <NUM>°-<NUM>°. Nipple is a sealable fitting, for example - a Luer (or medical) fitting, NPT, straight tube, compression, quick-connect, or any other suitable fitting.

Membrane cartridge <NUM> generally includes a bundle of membranes (e.g., hollow fiber membranes) <NUM> surrounding and bonded to a perforated center tube <NUM>, see <FIG>. The cartridge <NUM> has a first end <NUM> and a second end <NUM>. A plug <NUM> is disposed in the center tube <NUM> adjacent second end <NUM>. A mating internal surface <NUM> is located at the first end of the perforated center tube <NUM> adjacent the first end <NUM>. Mating internal surface <NUM> may be beveled. Mating internal surface <NUM> may complement the angle of mating external surface <NUM>. The hollow fiber membranes of bundle <NUM> are closed at the first end <NUM> and open at the second end <NUM>. The bundle <NUM> may be bonded to the center tube <NUM> by a potting material. Potting material (e.g., epoxy, polyurethane, thermoplastic polymer, and/or adhesive) may be formed into walls <NUM> at the first end <NUM> and the second end <NUM> of the cartridge <NUM>.

<FIG> illustrates that cartridge <NUM> may be made two-at-a-time, cartridge 16A and 16B. The membrane are wound around the center tube <NUM>, so that the end of the membranes are closed 58A and 58B. If the membrane is a plurality of hollow fibers, the hollow fibers may be knit into a fabric (the lateral edges of the fabric will have closed or looped over ends) and then wound around the center tube <NUM>. The membranes may be joined to the center tube <NUM> in a conventional fashion, i.e., potting at 66A, 66A/B, and 66B. Then, cartridge 16A and cartridge 16B are separated (e.g., cut apart) along line <NUM>. Plugs <NUM> may be formed at the same time that the potting at 66A/B are formed.

When assembled, see <FIG>, (or assembling), cartridge <NUM> is inserted into cup body <NUM> by engaging mating surface <NUM> of the center tube <NUM> with the mating surface <NUM> of the end port <NUM>. These mating surfaces <NUM> and <NUM> must be held in sealing engagement when cartridge <NUM> is fixed to cup body <NUM>. This sealing engagement may be accomplished by luer lock, press fit, interference fit, snap fit, threading, welding, and/or gluing. These mating surfaces <NUM> and <NUM> may be held in sealing engagement when cartridge <NUM> is fixed to cup body <NUM> by, for example, material <NUM> or a mechanism (not shown). The material <NUM> or the mechanism also seals the cartridge <NUM> and cup body <NUM> in fluid tight engagement. Material <NUM> may be any material conventionally known in the art. Such materials <NUM> include potting and/or glue. Such mechanisms include threading, clips, o-rings, snap fittings. Once the cartridge <NUM> is fixed into cup body <NUM>, cap <NUM> is joined to the assembly of the cartridge <NUM> and cup body <NUM> via joint <NUM>. Joint <NUM> is a fluid tight joint. Joint <NUM> may be a welded joint or glued joint. The welded joint may be formed by spin welding. Headspace <NUM> is formed between cap <NUM> and the assembly of cup body <NUM> and cartridge <NUM>, when shoulder <NUM> of cap <NUM> rest on shoulder <NUM> of cup body <NUM>.

In one embodiment, in operation, gas entrained liquid enters contactor <NUM> via end port <NUM> and travels along center tube <NUM> until blocked by plug <NUM>. The gas entrained liquid exits the perforated center tube <NUM> and travels radially across the external surfaces of the hollow fiber membranes, and exits contactor <NUM> via side port <NUM> (this path defines the shell side). Vacuum or vacuum/sweep gas are introduced via cap port <NUM> and are in fluid communication with the lumens of the hollow fibers via headspace <NUM> (this path defines the tube side). The entrained gas is drawn from the liquid across the membranes and exits via cap port <NUM>.

Claim 1:
A membrane contactor comprises:
a cap (<NUM>) has an internally facing joining surface (<NUM>') which is an internally beveled surface and a cap port;
a cup body (<NUM>) has an externally facing joining surface (<NUM>") which is an externally beveled surface in sealing engagement with the internally facing joining surface, a side port (<NUM>) on a side of the cup body, and an end port (<NUM>) located on an end of the cup body, the end port (<NUM>) comprising an inwardly extending nipple (<NUM>) with a mating external surface (<NUM>) that is beveled; and
a membrane cartridge (<NUM>) is located within the cup body, is sealed to an open end of the cup body, and is in sealed fluid communication with the end port;
wherein the membrane cartridge includes a perforated center tube (<NUM>), a first end of the center tube having a mating internal surface (<NUM>) that is beveled, the mating internal surface (<NUM>) being adapted to sealingly join with the mating external surface (<NUM>) of the end port, and a second end of the center tube is plugged, and a bundle (<NUM>) of hollow fibers surrounding and potted to the center tube, the hollow fibers are closed adjacent the first end of the center tube and open adjacent the second end of the center tube, and
wherein the first end of the center tube is held in sealing engagement with the end port by the cartridge being sealed to the cup body.