This invention generally relates to static mixers for mixing two or more fluids in a fluid dispenser, and particularly to a static mixer configured to mix blood with one or more other fluids.
A number of motionless mixer types exist, such as Multiflux, helical, and others. These mixer types, for the most part, implement the same general principle to mix fluids together. In these mixers, fluids are mixed together by dividing and recombining the fluids in an overlapping manner. This action is achieved by forcing the fluid over a series of baffles of alternating geometry. Such division and recombination causes the layers of the fluids being mixed to thin and eventually diffuse past one another. This mixing process has proven to be very effective, especially with high viscosity fluids.
Static mixers are typically constructed of a series of alternating baffles, of varying geometries, usually consisting of right-handed and left-handed mixing baffles disposed in a conduit to perform the continuous division and recombination. Such mixers are generally effective in mixing together most of the mass fluid flow, but these mixers typically include a plurality of baffles with complex geometry and shapes. This complex geometry is difficult to produce in a molding process reliably and may not release properly from a mold, which leads to a significant amount of wasted material and increased cost. Additionally, the molding process may also result in irregularities and sharp features being formed throughout the baffles. These sharp features and complex baffles may adversely affect certain fluids passing through the static mixer. For example, static mixers are used in the medical field to mix blood with one or more other fluids before delivery to a patient. Conventional static mixers may destroy red blood cells in blood passing through the static mixer whenever the blood passes sharp or irregular features. As a result, the blood exiting the static mixer may not be suitable for the patient.
There is a need, therefore, for a static mixer that addresses these and other problems associated with conventional mixers.
In one embodiment of the invention, a static mixer for mixing a fluid flow includes a plurality of mixer baffle segments which may be positioned in a mixer conduit. The plurality of mixer baffle segments defines a direction of flow through the static mixer. The mixer baffle segments are configured to divide and rotate the fluid flow. Each of the mixer baffle segments consists of a plurality of planar baffle plates interconnected together to form pairs of adjacent baffle plates oriented generally perpendicular to each other along adjoining edges. The adjoining edges may be chamfered. As such, the plurality of mixer baffle segments is reliable to manufacture and minimizes the number of sharp corners that the fluid flow must pass through when being mixed in the static mixer.
Each of the mixer baffle segments may further include a plurality of planar divider baffle plates interconnected together and extending generally parallel to the direction of flow. The planar divider baffle plates divide the mixer conduit into four quadrants. Each of the mixer baffle segments may also include a plurality of planar occluding baffle plates interconnected to the plurality of planar divider baffle plates. The planar occluding baffle plates extend generally perpendicular to the direction of flow so as to occlude at least one of the four quadrants. The plurality of mixer baffle segments may include a first mixer baffle segment configured to rotate the fluid flow counter-clockwise in the direction of flow and a second mixer baffle segment configured to rotate the fluid flow clockwise in the direction of flow. The first and second mixer baffle segments may be arranged in alternating relation such that the fluid flow through the mixer conduit is divided and rotated in different directions through the mixer conduit.
In another embodiment of the invention, a static mixer for mixing a fluid flow includes a plurality of mixer baffle segments which may be disposed in a mixer conduit along a direction of flow. Each of the mixer baffle segments includes a first planar divider baffle plate having a first leading edge and a first trailing edge, a second planar divider baffle plate having a second leading edge and a second trailing edge, and a third planar divider baffle plate having a third leading edge and a third trailing edge. Each of the first, second, and third planar divider baffle plates extends parallel to the direction of flow, and the second planar divider baffle plate is coupled in perpendicular relationship with each of the first and third planar divider baffle plates. Thus, the first, second, and third planar divider baffle plates effectively divide the mixer conduit into first, second, third, and fourth quadrants.
Each of the mixer baffle segments also includes first, second, third, and fourth planar occluding baffle plates extending generally perpendicular to the direction of flow. The first planar occluding baffle plate is connected to the first trailing edge of the first planar divider baffle plate and the second leading edge of the second planar divider baffle plate so as to block flow in the first quadrant. The second planar occluding baffle plate is connected to the second trailing edge of the second planar divider baffle plate and the third leading edge of the third planar divider baffle plate so as to block flow in the second quadrant. The third planar occluding baffle plate is connected to the first trailing edge of the first planar divider baffle plate and the second leading edge of the second planar divider baffle plate so as to block flow in the third quadrant. The fourth planar occluding baffle plate is connected to the second trailing edge of the second planar divider baffle plate and the third leading edge of the third planar divider baffle plate so as to block flow in the fourth quadrant. Certain adjoining edges of the planar divider baffle plates and planar occluding baffle plates may be chamfered, thereby minimizing the number of sharp corners for the fluid flow to traverse in the mixer conduit.
The static mixer 12 shown in
As more clearly shown in
As briefly described above, the first, second, and third planar divider baffle plates 40, 42, 44 divide the mixer conduit (not shown in
The first mixer baffle segment 30 further includes a first planar occluding baffle plate 50 extending perpendicular to the direction of flow F. The first planar occluding baffle plate 50 is coupled to the second leading edge 42a of the second planar divider baffle plate 42 and the first trailing edge 40b of the first planar divider baffle plate 40. The first planar occluding baffle plate 50 includes a front side 50a, a rear side 50b, and an outer edge 50c configured to abut the interior wall 14 of the mixer conduit 12. In this regard, the first planar occluding baffle plate 50 extends above the upper side 42c of the second planar divider baffle plate 42 and to the left of the left side 40c of the first planar divider baffle plate 40 such that the first planar occluding baffle plate 50 blocks fluid flow in the first quadrant Q1. As explained in further detail below, the first planar occluding baffle plate 50 forces fluid flow on the left side 40c of the first planar divider baffle plate 40 below the second planar divider baffle plate 42.
The first mixer baffle segment 30 also includes a second planar occluding baffle plate 52 extending perpendicular to the direction of flow F. The second planar occluding baffle plate 52 is coupled to the second trailing edge 42b of the second planar divider baffle plate 42 and the third leading edge 44a of the third planar divider baffle plate 44. The second planar occluding baffle plate 52 includes a front side 52a , a rear side 52b, and an outer edge 52c configured to reside adjacent the interior wall 14 of the mixer conduit 12. The second planar occluding baffle plate 52 extends above the upper side 42c of the second planar divider baffle plate 42 and to the right of the right side 44d of the third planar divider baffle plate 44. The second planar occluding baffle plate 52 blocks fluid flow in the second quadrant Q2. Again as explained below, the second planar occluding baffle plate 52 forces fluid flow above the upper side 42c of the second planar divider baffle plate 42 to the left of the third planar divider baffle plate 44.
The first mixer baffle segment 30 further includes a third planar occluding baffle plate 54 extending generally perpendicular to the direction of flow F. The third planar occluding baffle plate 54 is coupled to the second leading edge 42a of the second planar divider baffle plate 42 and the first trailing edge 40b of the first planar divider baffle plate 40. The third planar occluding baffle plate 54 includes a front side 54a, a rear side 54b, and an outer edge 54c configured to reside adjacent the interior wall 14 of the mixer conduit 12. The third planar occluding baffle plate 54 extends below the lower side 42d of the second planar divider baffle plate 42 and to the right of the right side 40d of the first planar divider baffle plate 40. Therefore, the third planar occluding baffle plate 54 blocks fluid flow in the third quadrant Q3. To this end, the third planar occluding baffle plate 54 forces fluid flow to the right of the first planar divider baffle plate 40 above the second planar divider baffle plate 42.
The first mixer baffle segment 30 also includes a fourth planar occluding baffle plate 56 extending generally perpendicular to the direction of flow F. The fourth planar occluding baffle plate 56 is coupled to the second trailing edge 42b of the second planar divider baffle plate 42 and the third leading edge 44a of the third planar divider baffle plate 44. The fourth planar occluding baffle plate 56 includes a front side 56a, a rear side 56b, and an outer edge 56c configured to abut the interior wall 14 of the mixer conduit 12. The fourth planar occluding baffle plate 56 extends generally below the lower side 42d of the second planar divider baffle plate 42 and to the left of the left side 44c of the third planar divider baffle plate 44. Consequently, the fourth planar occluding baffle plate 56 blocks fluid flow in the fourth quadrant Q4. In this regard, the fourth planar occluding baffle plate 56 forces fluid flow below the lower side 42d of the second planar divider baffle plate 42 to the right of the third planar divider baffle plate 44.
As shown in
As described previously, the plurality of planar baffle plates 40, 42, 44, 50, 52, 54, 56 may be chamfered along certain adjoining edges to minimize the number of sharp corners encountering the flow passing through the static mixer 10. For example, a chamfered surface 66 may be formed at the adjoining edge of the upper side 42c of the second planar divider baffle plate 42 and the front side 54a of the third planar occluding baffle plate 54. In another example, a chamfered surface 66 may be formed between the front side 52a of the second planar occluding baffle plate 52 and the left side 44c of the third planar divider baffle plate 44. Likewise, another chamfered surface 66 may be formed between the right side 40d of the first planar divider baffle plate 40 and the rear side 50b of the first planar occluding baffle plate 50. Additionally, another chamfered surface 66 may be formed between the upper side 42c of the second planar divider baffle plate 42 and the rear side 56b of the fourth planar occluding baffle plate 56. It will be understood that additional chamfered surfaces 66 may be formed along any adjoining edges of any pair of adjacent baffle plates without departing from the scope of this invention.
The fourth cross section of the fluid flow (at 73) shown in
In sum, the first mixer baffle segment 30 has rotated the flow 180 degrees counter-clockwise in the direction of flow F and mixed the first and second fluids A, B together. The fluid flow passes a minimized number of sharp corners because of the inclusion of the various chamfered surfaces 66. Consequently, a sensitive fluid such as blood may avoid significant damage to red blood cells or other components during passage through the static mixer 10. Furthermore, the planar shape of each of the baffle plates 40, 42, 44, 50, 52, 54, 56 provides a non-complex overall geometry that is easy to manufacture in an injection molding process or other known process. In this regard, the first mixer baffle segment 30 reliably releases from a mold without irregularities or sharp features being added to the first mixer baffle segment 30. In embodiments where the first mixer baffle segment 30 is injection molded, the baffle plates are formed from materials that meet ISO-10993 test requirements for levels of toxicity. For example, the baffle plates may be composed of a thermoplastic polymer such as polypropylene or ABS (acrylonitrile butadiene styrene).
As more clearly shown in
The second mixer baffle segment 32 further includes a first planar occluding baffle plate 90 extending perpendicular to the direction of flow F. The first planar occluding baffle plate 90 is coupled to the second leading edge 82a of the second planar divider baffle plate 82 and the first trailing edge 80b of the first planar divider baffle plate 80. The first planar occluding baffle plate 90 includes a front side 90a, a rear side 90b, and an outer edge 90c configured to abut the interior wall 14 of the mixer conduit 12. In this regard, the first planar occluding baffle plate 90 extends above the upper side 80c of the first planar divider baffle plate 80 and to the left of the left side 82c of the second planar divider baffle plate 82 such that the first planar occluding baffle plate 90 blocks fluid flow in the first quadrant Q1. As explained in further detail below, the first planar occluding baffle plate 90 forces fluid flow above the upper side 80c of the first planar divider baffle plate 80 to the right of the second planar divider baffle plate 82.
The second mixer baffle segment 32 also includes a second planar occluding baffle plate 92 extending perpendicular to the direction of flow F. The second planar occluding baffle plate 92 is coupled to the second trailing edge 82b of the second planar divider baffle plate 82 and the third leading edge 84a of the third planar divider baffle plate 84. The second planar occluding baffle plate 92 includes a front side 92a, a rear side 92b, and an outer edge 92c configured to reside adjacent the interior wall 14 of the mixer conduit 12. The second planar occluding baffle plate 92 extends above the upper side 84c of the third planar divider baffle plate 84 and to the right of the right side 82d of the second planar divider baffle plate 82. The second planar occluding baffle plate 92 blocks fluid flow in the second quadrant Q2. Thus, the second planar occluding baffle plate 92 forces fluid flow on the right side 82d of the second planar divider baffle plate 82 below the third planar divider baffle plate 84.
The second mixer baffle segment 32 further includes a third planar occluding baffle plate 94 extending generally perpendicular to the direction of flow F. The third planar occluding baffle plate 94 is coupled to the second leading edge 82a of the second planar divider baffle plate 82 and the first trailing edge 80b of the first planar divider baffle plate 80. The third planar occluding baffle plate 94 includes a front side 94a, a rear side 94b, and an outer edge 94c configured to reside adjacent the interior wall 14 of the mixer conduit 12. The third planar occluding baffle plate 94 extends below the lower side 80d of the first planar divider baffle plate 80 and to the right of the right side 82d of the second planar divider baffle plate 82. Therefore, the third planar occluding baffle plate 94 blocks fluid flow in the third quadrant Q3. To this end, the third planar occluding baffle plate 94 forces fluid flow below the first planar divider baffle plate 80 to the left of the second planar divider baffle plate 82.
The second mixer baffle segment 32 also includes a fourth planar occluding baffle plate 96 extending generally perpendicular to the direction of flow F. The fourth planar occluding baffle plate 96 is coupled to the second trailing edge 82b of the second planar divider baffle plate 82 and the third leading edge 84a of the third planar divider baffle plate 84. The fourth planar occluding baffle plate 96 includes a front side 96a, a rear side 96b, and an outer edge 96c configured to abut the interior wall 14 of the mixer conduit 12. The fourth planar occluding baffle plate 96 extends generally below the lower side 84d of the third planar divider baffle plate 84 and to the left of the left side 82c of the second planar divider baffle plate 82. Consequently, the fourth planar occluding baffle plate 96 blocks fluid flow in the fourth quadrant Q4. The fourth planar occluding baffle plate 96 forces fluid on the left side 82c of the second planar divider baffle plate 82 above the third planar divider baffle plate 84.
As shown in
The fourth cross section of the fluid flow (at 103) shown in
In sum, the second mixer baffle segment 32 has rotated the flow 180 degrees clockwise in the direction of flow and further mixed the first and second fluids A, B together. The fluid flow passes a minimized number of sharp corners because of the inclusion of the various chamfered surfaces 66. Consequently, a sensitive fluid such as blood may avoid significant damage to red blood cells or other components during passage through the static mixer 10. Furthermore, the planar shape of each of the baffle plates 80, 82, 84, 90, 92, 94, 96 provides a non-complex overall geometry that is easy to manufacture such as by injection molding a thermoplastic material.
The plurality of first and second mixer baffle segments 30, 32 may be integrally formed as a single mixer baffle segment stack 20 or may be separately molded and interconnected together to form the mixer baffle segment stack 20. In one example, the plurality of mixer baffle segments 30, 32 may be integrally formed by an injection molding process. Each mixer baffle segment 30, 32 defines a length of approximately 0.6 inches. Consequently, the mixer baffle segments 30, 32 may be interconnected together to fill any length of mixer conduit 12 such as a mixer conduit 12 having a length of 1.8 inches (like the mixer baffle segment stack 20 shown in
Advantageously, each of the planar baffle plates in each of the mixer baffle segments 30, 32 is shaped to be planar such that the plurality of mixer baffle segments 30, 32 does not include any complex geometries or irregular shapes. As a result, the plurality of mixer baffle segments 30, 32 reliably releases from a mold in an injection molding process, and irregularities in the static mixer 10 are reduced or eliminated. Therefore, the static mixer 10 of the embodiment illustrated in
While the present invention has been illustrated by the description of a specific embodiment thereof, and while the embodiment has been described in considerable detail, it is not intended to restrict or in any way limit the scope of the appended claims to such detail. The various features discussed herein may be used alone or in any combination. Additional advantages and modifications will readily appear to those skilled in the art. For example, the seven described baffle plates of each mixing baffle segment may be added to additional baffle plates in other embodiments of the static mixer. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and methods and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the scope or spirit of the general inventive concept.
This application claims the priority of U.S. Provisional Patent Application Ser. No. 61/317,531, filed on Mar. 25, 2010 (pending), the disclosure of which is incorporated by reference herein.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/US2011/029775 | 3/24/2011 | WO | 00 | 7/26/2012 |
Number | Date | Country | |
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61317531 | Mar 2010 | US |