1. A helically wound hollow fiber membrane module comprising:
(a) a core;
(b) a plurality of helically wound layers of semi-permeable hollow fibers wound on the core, wherein the fiber wind angle with respect to any one layer of fibers is essentially constant along the axial length of the module, except in one or both end or tubesheet regions, where the wind angle is increased, in at least some of the layers relative to the essentially constant wind angle, to produce an area of decreasing diameter and packing fraction.
2. The helically wound hollow fiber membrane module of claim 1, wherein the diameter of the module at the beginning of the one or both end regions is substantially the diameter of the hollow fiber membrane module at the central active region, and is less than the diameter of the central active region at the other end of the one or both end or tubesheet regions.
3. The helically wound hollow fiber membrane module of claim 2, wherein the diameter of the module at the other end of the one or both end regions is only slightly larger than the diameter of the core.
4. The helically wound hollow fiber membrane module of claim 2, further comprising at least one end or tubesheet region, a portion of which is an active region, and a central active region.
5. The helically wound hollow fiber membrane module of claim 4, wherein a potted on end cap covers at least a portion of the at least one tubesheet region.
6. The helically wound hollow fiber membrane module of claim 5, wherein the hollow fiber membrane module has a tubesheet region at each end, with an active region extending between the tubesheet regions, wherein a potted on endcap is provided on each of the tubesheet regions, and each potted on endcap covers at least a portion of its respective tubesheet region.
7. The helically wound hollow fiber membrane module of claim 5, wherein the module is covered with a closely conforming barrier material which is impervious to gas and extends over the entirety of the module except for a non-covered region adjacent the at least one tubesheet region.
8. The helically wound hollow fiber membrane module of claim 6, wherein the module is covered with a closely conforming barrier material which is impervious to gas and extends over the entirety of the module.
9. The helically wound hollow fiber membrane module of claim 6, wherein the module is covered with a closely conforming barrier material which is impervious to gas and extends over the entirety of the module except for a non-covered region adjacent the at least one tubesheet region.
10. The helically wound hollow fiber membrane module of claim 6, wherein the module is covered with a closely conforming barrier material which is impervious to gas and extends over the entirety of the module.
11. The helically wound hollow fiber membrane module of claim 7 sealingly mounted inside a shell.
12. The helically wound hollow fiber membrane module of claim 9 sealingly mounted in side a shell.
13. The helically wound hollow fiber membrane module of claim 11, wherein there is a seal between the impervious barrier material and the shell.
14. The helically wound hollow fiber membrane module of claim 12, wherein there is a seal between the impervious barrier material and the shell.
15. An internal sweep, bore-side feed, helically wound hollow fiber membrane module comprising:
(a) the helically wound hollow fiber membrane module of claim 13, wherein the hollow core is cylindrical and is open at one end of the module for the introduction of sweep gas, and a plurality of sweep holes are provided in the hollow core proximate the active region to allow sweep gas to surround the outside of the fibers in the area defined between the core, the inside of the shell and the endcaps: and,
(b) At least one opening provided in the shell to allow the sweep gas to escape.
16. The construction defined in claim 15 further comprising a sweep orifice in the hollow core to limit the amount of sweep gas entering the core.
17. The construction defined in claim 15, further comprising a seal between the gas impervious material and the interior of the shell.
18. An external sweep, bore-side feed, module comprising:
(a) the helically wound hollow fiber membrane module of claim 13, wherein the closely conforming barrier material extends over the entirety of the module except for a non-covered region adjacent both tubesheet regions;
(b) a seal is provided between the gas impervious material and the interior of the shell;
(c) at least one sweep inlet opening is provided adjacent one end of the shell; and
(d) at least one sweep outlet opening is provided adjacent the other end of the shell.
19. The construction defined in claim 18, further comprising endcaps provided on each end of the shell.
20. The construction defined in claim 19, further comprising endcaps provided on each end of the shell.
21. The helically wound hollow fiber membrane module defined in claim 1, wherein the wind angle of different layers of fiber along the axial length of the module vary widely.
22. The helically wound hollow fiber membrane module defined in claim 1, wherein the length of the fibers in different layers of fiber along the axial length of the module vary by twenty percent or more.
23. The external sweep, bore-side feed, module defined in claim 18, wherein the hollow core is cylindrical.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A self-drilling anchor screw, comprising:
a shaft member comprising a first end, second end, and a central portion extending between the first and second ends;
a drill bit portion at the first end of the shaft member;
a threaded shaft portion located along at least part of the central portion of the shaft member;
a transition portion of the shaft member located between the threaded shaft portion and the drill bit portion, wherein at least part of the transition portion has a larger cross-section area than that of the threaded shaft portion;
a nut having nut threads adapted to thread onto the threaded shaft portion of the shaft member, and the nut being located on the threaded shaft portion;
a sleeve located about the shaft member and at least part of the sleeve being located adjacent to the transition portion, the sleeve being capable of sliding along the shaft member for engaging the transition portion; and
a nut stop portion at the second end of the shaft member, the nut stop portion being adapted to prevent the nut from being unscrewed from the threaded shaft portion at the second end of the shaft member, wherein a largest cross-section dimension of the nut stop portion, as taken perpendicular to a longitudinal axis of the shaft member, is smaller than an outside cross-section dimension of the nut, as taken perpendicular to the longitudinal axis of the shaft member.
2. The self-drilling anchor screw of claim 1, wherein the drill bit portion comprises a masonry bit.
3. The self-drilling anchor screw of claim 1, wherein the drill bit portion comprises a tungsten carbide tip.
4. The self-drilling anchor screw of claim 1, wherein the sleeve extends over and is adapted to slide over at least part of the threaded shaft portion.
5. The self-drilling anchor screw of claim 1, wherein the shaft member comprises a sleeve-retention portion located adjacent to the transition portion and located between the transition portion and the threaded portion, wherein the sleeve is located about the shaft member at the sleeve-retention portion, and wherein the sleeve-retention portion comprises a sleeve-stop portion adapted to hinder the sleeve from moving past the sleeve-stop portion toward the threaded portion.
6. The self-drilling anchor screw of claim 5, wherein the sleeve comprises a bump portion extending from an outside surface of the sleeve.
7. The self-drilling anchor screw of claim 1, wherein the nut comprises a hexagonal portion and a flared portion, the flared portion having a larger diameter than a hexagonal portion.
8. The self-drilling anchor screw of claim 1, wherein the drill bit portion comprises threaded flutes.
9. The self-drilling anchor screw of claim 8, wherein the threaded flutes spiral in a first spiral direction, wherein the threaded portion of the shaft member spiral in a second spiral direction, and wherein the first spiral direction is opposite the second spiral direction.
10. The self-drilling anchor screw of claim 9, wherein the drill bit portion is adapted to cut when rotating in a counter-clockwise direction, and wherein the first spiral direction is a reverse thread direction.
11. The self-drilling anchor screw of claim 8, wherein the threaded flutes spiral in a first spiral direction, and wherein the threaded portion of the shaft member spiral in the first spiral direction.
12. The self-drilling anchor screw of claim 1, further comprising a washer located about the central portion of the shaft member, wherein the washer is located between the nut and the sleeve.
13. The self-drilling anchor screw of claim 1, wherein the nut stop portion has an elongated shape extending from the second end of the shaft member.
14. The self-drilling anchor screw of claim 1, wherein the nut stop portion has a generally flattened shape.
15. The self-drilling anchor screw of claim 1, wherein the sleeve comprises a longitudinal slit for allowing the sleeve to expand as it is pushed against the transition portion of the shaft member.
16. A self-drilling anchor screw, comprising:
a shaft member comprising a first end, second end, and a central portion extending between the first and second ends;
a masonry drill bit at the first end of the shaft member;
a threaded shaft portion located along at least part of the central portion of the shaft member;
a transition portion of the shaft member located between the threaded shaft portion and the masonry drill bit, wherein at least part of the transition portion has a larger cross-section area than that of the threaded shaft portion;
a nut having nut threads adapted to thread onto the threaded shaft portion of the shaft member,
wherein the nut is located on the threaded shaft portion, and
wherein the nut comprises a hexagonal portion and a flared portion, the flared portion having a larger diameter than a hexagonal portion;
a sleeve located about the shaft member and located along part of the central portion between the nut and the transition portion, the sleeve being capable of sliding along the shaft member for engaging the transition portion, and the sleeve comprises a longitudinal slit for allowing the sleeve to expand as it is pushed against the transition portion of the shaft member; and
a nut stop portion at the second end of the shaft member, the nut stop portion being adapted to prevent the nut from being unscrewed from the threaded shaft portion at the second end of the shaft member, wherein a largest cross-section dimension of the nut stop portion, as taken perpendicular to a longitudinal axis of the shaft member, is smaller than an outside cross-section dimension of the hexagonal portion of the nut, as taken perpendicular to the longitudinal axis of the shaft member.
17. A self-drilling anchor screw, comprising:
a shaft member extending along a longitudinal axis of the screw, the shaft member comprising a first end, second end, and a central portion extending between the first and second ends;
a drill bit portion at the first end of the shaft member;
a threaded shaft portion located along at least part of the central portion of the shaft member;
a nut having nut threads adapted to thread onto the threaded shaft portion of the shaft member, and the nut being located on the threaded shaft portion;
an expandable sleeve located about the shaft member; and
a nut stop portion at the second end of the shaft member, the nut stop portion being adapted to prevent the nut from being unscrewed from the threaded shaft portion at the second end of the shaft member, wherein a largest cross-section dimension of the nut stop portion, as taken perpendicular to the longitudinal axis, is smaller than an outside cross-section dimension of the nut, as taken perpendicular to the longitudinal axis.
18. The self-drilling anchor screw of claim 17, wherein the drill bit portion comprises a masonry bit.
19. The self-drilling anchor screw of claim 17, further comprising:
a transition portion of the shaft member located between the threaded shaft portion and the drill bit portion, wherein at least part of the transition portion has a larger cross-section area than that of the threaded shaft portion, wherein at least part of the sleeve is located adjacent to the transition portion, and the sleeve being capable of sliding along the shaft member for engaging the transition portion.
20. The self-drilling anchor screw of claim 17, wherein the sleeve comprises a longitudinal slit for allowing the sleeve to expand.