Abstract
A diffuser head is adapted for local application of purified air to a target. The diffuser has a main body with an air inlet surface, that has a first area, towards an air outlet surface, that has a second area that is greater than the first area. The main body has a plurality of continuous expanding air ducts extending lengthwise between the air inlet surface and the air outlet surface, wherein an air duct has a third cross-sectional area that increases continuously from an air duct inlet at said air inlet surface towards an air duct outlet at said air outlet surface. If a filter provided at the air inlet surface, the diffuser head can be used in an air cleaning apparatus that has a pump for intake of air from the surrounding environment.
Claims
1. A diffuser head adapted for local application of purified air to a target, which diffuser head has a main body with an air inlet surface, that has a first area, towards an air outlet surface, that has a second area that is greater than the first area, wherein the main body has a plurality of continuous expanding air ducts 1) extending lengthwise between the air inlet surface and the air outlet surface, and 2) extending divergingly from each other from the air inlet surface towards the air outlet surface, and wherein an air duct has a third cross-sectional area (A) that increases continuously from an air duct inlet at said air inlet surface towards an air duct outlet at said air outlet surface.
2. (canceled)
3. A diffuser head according to claim 1, wherein an interior surface of an air duct is without substantial irregularities.
4. A diffuser head according to claim 3, wherein the interior surface of an air duct is smooth.
5. A diffuser head according to claim 1, wherein the plurality of continuous expanding air ducts is arranged about a longitudinal axis of the diffuser head in a uniform pattern.
6. A diffuser head according to claim 1, wherein the third cross-sectional area of an air duct of the plurality of continuous expanding air ducts is polygonal or follows a smooth closed curve, and/or the third cross-sectional area of an air duct is hexagonal or circular.
7. A diffuser head according to claim 1, wherein one or more of the air ducts of the plurality of continuous expanding air ducts have same or different third cross-sectional area.
8. A diffuser head according to claim 1, wherein the air outlet surface is concave, convex, and/or planar, and the air inlet surface is concave, convex and/or planar, combinations thereof.
9. A diffuser head according to claim 1, wherein the air outlet surface has a size of the second area that is at least 2 times larger than a size of the first area of the air inlet surface, and similar relation apply between the air duct outlet and the air duct inlet.
10. A diffuser head according to claim 1, wherein a diffuser head has a plurality of continuous expanding air ducts having lengths that are equal to or longer than the smallest widths or diameters of the air duct inlets.
11. A diffuser head according to claim 1, wherein the air velocity of air entering the air duct inlets from the surroundings and passing along air ducts having lengths that are longer than or equal to the smallest widths or diameters of the air duct inlets and out of the air duct outlets is maximum 0.15 m/s at a distance of between 35-60 cm from the air outlet surfaces of the air duct outlets.
12. A diffuser head according to claim 1, wherein the diffuser head has a head space above the air inlet surface that is maximum 10% of the total volume delimited circumferentially by the most exterior air ducts of the plurality of air ducts, the upper plane that traverses the main body and the air outlet surface.
13. A diffuser head according to claim 1, wherein at least the main body of the diffuser head is solid and the plurality of continuous expanding air ducts are bores or channels in the solid main body.
14. An air cleaning apparatus comprising the diffuser head according to claim 1, wherein the air cleaning apparatus further comprises a pump that drives air from the surroundings into the plurality of air duct inlets at the air inlet surface, along the plurality of air ducts, and out of the plurality of air duct outlets at the air outlet surface towards the target.
15. An air cleaning apparatus according to claim 14, wherein the air cleaning apparatus further comprises a turbulence reducing member upstream or downstream the pump.
16. An air cleaning apparatus according to claim 15, wherein the turbulence reducing member is made of a porous material.
17. An air cleaning apparatus according to claim 14, wherein the turbulence reducing member is a filter.
18. An air cleaning apparatus according to claim 15, wherein the turbulence reducing member is inserted between the pump and the diffuser head in a pipe piece in extension of the air inlet surface of the main body of the diffuser head.
19. An air cleaning apparatus according to claim 14, wherein the air cleaning apparatus further comprises a tubing or hose adapted for intake of air to be cleaned and delivered to the target via the diffuser head.
20. (canceled)
21. (canceled)
22. An air cleaning apparatus according to claim 15, wherein the turbulence reducing member is arranged at a location selected from the group of locations including between the air inlet surface and the pump, on the side of the pump opposite the side of the pump facing the air inlet surface, or in an air intake tube or hose remote from the diffuser head, and/or the pump is provided remote from the diffuser head in the air intake tube.
23. An air cleaning apparatus according to claim 14, wherein the pump that drives air from the surroundings into the plurality of air duct inlets at the air inlet surface is selected to provide an air velocity of maximum 0.15 m/s or 0.10 m/s at a distance of between 35-60 cm from the air outlet surfaces of the air duct outlets.
24. (canceled)
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0060] The invention will now be described below in further details by way of exemplary embodiments with reference to the accompanying drawing in which
[0061] FIG. 1a is a perspective view seen from the air inlet surface of a first embodiment of a diffuser head according to the present invention;
[0062] FIG. 1b is a sectional view taken along line 1b-1b in FIG. 1a;
[0063] FIG. 1c shows the diffuser head seen in FIG. 1a from the air inlet surface;
[0064] FIG. 1d shows the diffuser head seen in FIG. 1a from the air outlet surface;
[0065] FIG. 1e shows the diffuser head seen in FIG. 1a from the side;
[0066] FIG. 2a is a perspective view seen from the air inlet surface of a second embodiment of a diffuser head according to the present invention;
[0067] FIG. 2b is a sectional view taken along line 1ib-1ib in FIG. 2a;
[0068] FIG. 2c shows the diffuser head seen in FIG. 2a from the air inlet surface;
[0069] FIG. 2d shows the diffuser head seen in FIG. 2a from the air outlet surface;
[0070] FIG. 2e shows the diffuser head seen in FIG. 2a from the side;
[0071] FIG. 3a is a perspective view seen from the air inlet surface of a third embodiment of a diffuser head according to the present invention;
[0072] FIG. 3b is a sectional view taken along line IIIb-IIIb in FIG. 3a;
[0073] FIG. 3c shows the diffuser head seen in FIG. 3a from the air inlet surface;
[0074] FIG. 3d shows the diffuser head seen in FIG. 3a from the air outlet surface;
[0075] FIG. 3e shows the diffuser head seen in FIG. 3a from the side;
[0076] FIG. 4a is a perspective view seen from the air inlet surface of a fourth embodiment of a diffuser head according to the present invention;
[0077] FIG. 4b is a sectional view taken along line IVb-IVb in FIG. 4a;
[0078] FIG. 4c shows the diffuser head seen in FIG. 4a from the air inlet surface;
[0079] FIG. 4d shows the diffuser head seen in FIG. 4a from the air outlet surface;
[0080] FIG. 4e shows the diffuser head seen in FIG. 4a from the side;
[0081] FIG. 5a is a perspective view seen from the air inlet surface of a fifth embodiment of a diffuser head according to the present invention;
[0082] FIG. 5b is a sectional view taken along line Vb-Vb in FIG. 5a;
[0083] FIG. 5c shows the diffuser head seen in FIG. 5a from the air inlet surface;
[0084] FIG. 5d shows the diffuser head seen in FIG. 5a from the air outlet surface;
[0085] FIG. 5e shows the diffuser head seen in FIG. 5a from the side;
[0086] FIG. 6 is an exploded perspective view of an air cleaning apparatus comprising the fourth embodiment of a diffuser head;
[0087] FIG. 7 shows the same in assembled state oblique from above;
[0088] FIG. 8 shows the same from above;
[0089] FIG. 9 is a perspective view of the air cleaning apparatus seen in FIG. 6 in operative state in relation to a target;
[0090] FIG. 10 is an exploded perspective view of a modification of the air cleaning apparatus seen in FIG. 6;
[0091] FIG. 11 shows in exploded perspective a sixth embodiment of a diffuser head according to the present invention,
[0092] FIG. 12 shows the headspace above the air inlet surface illustrated on the first embodiment;
[0093] FIG. 13 shows the cleaning efficiency of the air cleaning apparatus shown in FIGS. 6-9; and
[0094] FIG. 14 shows the air velocity at difference distances from a longitudinal axis of a diffuser head situated about 35 cm from the target.
DETAILED DESCRIPTION OF THE INVENTION
[0095] The first embodiment of a diffuser head 1 seen in figs, 1a-1e is cone-shaped. A plurality of air ducts 2, all having regular hexagonal cross-sections, extends divergingly from each other from an air inlet surface 3, with a first area A1 towards an air outlet surface 4 with a second area A2. As illustrated best in FIGS. 1c and 1d the third cross-sectional area A of an air duct inlet 5 at the air inlet surface 3 is much smaller than the third cross-sectional area A of an air duct outlet 6 of said air duct 2 at the air outlet surface 4 due to the air ducts 2 expanding the whole of its length from said air inlet surface 3 to said air outlet surface 4, as seen in FIG. 1b. At the air inlet surface 3 the diffuser head 1 is provided with a short tubular extension 7 for one or more of accommodating e.g. an optional filter means (not shown) coupling to a supply tube for supplying air from the surrounding environment, coupling to a pipe piece for accommodating a pump means, as will be described later in relation to yet an embodiment of a diffuser head. The short tubular extension 7 extends towards the air inlet surface 3 into the conical main body 8 of the diffuser head 1, which conical main body 8 has an exterior circumferential wall 9 around the plurality of air ducts 2, an upper plane PI and a lower surface SI. The upper plane PI is the same as the air inlet surface 3, so there is no head space between the tubular extension 7, which is not part of the main body 7, and the air inlet surface 3, as seen best in FIG. 1b. The lower surface SI is the same as air outlet surface 4. For the first embodiment of a diffuser head 1 of the present invention the air inlet surface 3 and the air outlet surface 4 are planar and parallel. The partition walls 10 between the adjacent air ducts 2 of the plurality extend the whole length from the air inlet surface 3 to the air outlet surface 4 and the most exterior air ducts of the plurality of air ducts terminate in the circumferential wall 9.
[0096] A second embodiment of a diffuser head 11 is seen in FIGS. 2a-2e. The second embodiment of a diffuser head 11 differs from the first embodiment of a diffuser head 1 mainly in having a main body 12 that has an exterior circumferential wall 13 that is trumpet-shaped or flared instead of conical, and in the air outlet surface 16 being concave, when seen from below the diffuser head 11. The second embodiment of a diffuser head 11 has an upper plane P2 and a lower surface SI. The upper plane P2 is the same as the air inlet surface 15, so there is no head space between the tubular extension 7, which is not part of the main body 12, and the air inlet surface 15, as seen best in FIG. 2b. The lower surface S2 is the same as the air outlet surface 16. A plurality of air ducts 14, all being regular or close to regular hexagonal, has third cross-sectional areas A at the air inlet surface 15 but irregular hexagonal third cross-sectional areas A1 at the air outlet surface 16 due to the trumpet- or flared shape of the main body 12. The plurality of air ducts 14 extends divergingly from each other from the air inlet surface 15 towards the air outlet surface 16. The air ducts 14 closest to the exterior circumferential wall 13 having the most irregular hexagonal third cross-sectional areas A1, and the air ducts 14 closest to the center longitudinal axis of the diffuser head 11 having the most regular hexagonal third cross-sectional areas A. The air ducts 14 expand the whole of their length, as seen in FIG. 2b. At the air inlet surface 15 the diffuser head 11 is provided with a short tubular extension 7 to be used as described for the first embodiment of a diffuser head 1, The partition walls 17 between the adjacent air ducts 14 of the plurality extend the whole length from the substantially planar air inlet surface 15 to the substantially planar air outlet surface 16. The most exterior air ducts of the plurality of air ducts terminate in the circumferential wall 13, which has an increased thickness at the upper plane due to the trumpet- or flared shape of the main body 12.
[0097] A third embodiment of a diffuser head 18 is seen FIGS. 3a-3e. The third embodiment of a diffuser head 18 is a modification of the first embodiment of a diffuser head 1 and differs from said first embodiment of a diffuser head 1 mainly in that the air outlet surface 19 is convex, when seen from below the diffuser head 18 opposite the air inlet surface 3, and in being less conical. However for the third embodiment of a diffuser head 18 the main body 20 is also conical, and the main body of the diffuser head 18 also has a tubular extension 7′, but then tubular extension ‘I’ is longer than the tubular extension 7 of the first embodiment of a diffuser head 1. The convex curvature of said air outlet surface 19 compensates for the small conicity of the exterior circumferential wall 21 of the main body 20 to still offer a large air outlet surface 19. The third embodiment of a diffuser head 18 has an upper plane P3 and a lower surface S3. The upper plane P3 is the same as the air inlet surface 3, so there is no head space between the tubular extension 7′, which is not part of the main body 20, and the air inlet surface 3, as seen best in FIG. 3b. The lower surface S3 is the same as air outlet surface 19. The air ducts 22 expand the whole of their length, as seen in FIG. 3b and has third cross-sectional areas A that are regular hexagonal except from the parts protruding beyond the exterior circumferential wall 21. At the outlet surface 19 the air duct outlets 22 thus curve in accordance with the convex curvature of said outlet surface 19.
[0098] The third embodiment of a diffuser head 18 can e.g. be made by 2K molding. The diffuser head 18 can thus be made as a rigid component of a thermosetting plastic polymer or of a thermoplastic polymer and the tubular extension ‘I’ be made in same molding operation of an elastomeric polymer, thereby providing a diffuser head 18 with the ability to be elastically fitted on a coupling piece of a supply tube for supplying the air from the surrounding environment to be diffused and/or cleaned.
[0099] An elastic tubular extension can be provided on any of the embodiments of a diffuser head within the scope of the present invention. Such a diffuser head can be mounted on coupling pieces with diameters with mounting tolerance and mounting can be done without tools, and in different installations.
[0100] A fourth embodiment of a diffuser head 23 is seen FIGS. 4a-4e. The fourth embodiment of a diffuser head 23 differs from the first embodiment of a diffuser head 1, the second embodiment of a diffuser head 11 and the third embodiment of a diffuser head 18 in that the main body 24 is hemispherical and delimited by a hemispherical exterior circumferential wall 25, thus the air outlet surface 26 is convex as for the third embodiment of a diffuser head 18. The air ducts 27 are separated by partition walls 17′ and expand the whole of their length from the air inlet surface 28 to the air outlet surface 26, as seen in FIG. 4b, and has third cross-sectional areas A that are regular hexagonal. The fourth embodiment of a diffuser head 23 also differs from the previously discussed embodiments in that the tubular extension 29 has locking webs 30a, 30 that protrude radially, inwards to mate below corresponding locking webs of another component to assemble the diffuser head. The fourth embodiment of a diffuser head 23 has an upper plane P4 and a semi-hemispherical lower surface S4 that includes the air outlet surface 26 defined by the plurality of air duct outlets. The upper plane P4 is the same as the air inlet surface 28, so there is no head space between the tubular extension 29, which is not part of the main body 24, and the air inlet surface 28, as seen best in FIG. 4b.
[0101] An alternative configuration of a tubular extension that can lock with other components may in the alternative have an internal or external screw thread or snap-fitting means.
[0102] A fifth embodiment of a diffuser head 31 is seen FIGS. 5a-5e. The fifth embodiment of a diffuser head 31 differs from the fourth embodiment of a diffuser head 23 in the tubular extension being the tubular extension 7 of the first embodiment of a diffuser head 1, and in that the air ducts 32, that are separated by partitions walls 17′ expand the whole of their length from the air inlet surface 33 to the air outlet surface 34, has third cross-sectional areas A that are circular. The fifth embodiment of a diffuser head 31 has an upper plane P5 and a semi-hemispherical lower surface S4 that includes the air outlet surface 34 defined by the plurality of air duct outlets. The upper plane P5 is the same as the air inlet surface 33, so there is no head space between the tubular extension 7, which is not part of the main body 24, and the air inlet surface 28, as seen best in FIG. 4b.
[0103] The wall thickness of the partition walls is kept as little as possible to obtain the largest possible number of air ducts within the main body, and still preserve the dimensional configuration and structural stability of the diffuser head.
[0104] FIGS. 6, 7 and 8 illustrate an air cleaning apparatus 35 comprising, as an example, the fourth embodiment of a diffuser head 23, a filter means 36, such as e.g. a HEPA filter, a pump means 37 in form of a fan, and a connection piece 38 that also may serve as a housing for the filter means 36 and the pump means 37. The connection piece 38 is then connected to an air supply tube or hose (not shown). The pump means may be driven by an electric motor (not shown) also stored in the connection piece 38. Alternatively, the pump means may be located remote from the diffuser head 23, e.g. in the air supply tube (not shown).
[0105] FIG. 9 is a perspective view of the air cleaning apparatus 35 seen in FIG. 7 in operative state in relation to a target 39, which target in the present example, is a baby. The air cleaning apparatus 35 spreads the flow of purified air produced by the diffuser head 23 into a cone-shaped clean zone 40.
[0106] FIG. 10 is an exploded perspective view of a modification 41 of the air cleaning apparatus seen in FIG. 6. The air cleaning apparatus 41 differs from the air cleaning apparatus 35 in that the axial order of the filter means 36 and the pump means 37 has been reversed, and in that a counter-rotation device 42 has been inserted between the pump means 37 and the diffuser head 23 to compensate for potential turbulence induced by the pump means 37 to thereby supply a substantially balanced flow of air into the air ducts to further ensure that the flow of diffused air out of the plurality of air ducts is as close to laminar as possible. In FIG. 10 the connection piece 38 is illustrated transparent to show that the filter means 36 may be positioned inside it.
[0107] It is emphasised that any of the components above the air inlet surface may be wider than the air inlet surface e.g. by virtue of extending radially into the aforementioned surrounding jacket, or due to the tubular extension expanding away from the air inlet surface, or due to the exterior wall at the air inlet surface enlarges the exterior perimeter of the diffuser head at the location of the air inlet surface.
[0108] The filter means may be arranged spaced from the air inlet surface, or simply rest on the air inlet surface.
[0109] It should be noted that the air outlet surface is at least double as large than the air inlet surface.
[0110] In the first embodiment of a diffuser head 1, seen in figs, 1a-1e, the air outlet surface is about 7 times larger than the air inlet surface. In the second embodiment of a diffuser head 11 seen in FIG. 2 the air outlet surface is about 5 times larger than the air inlet surface. In the third embodiment of a diffuser head 18 seen in FIGS. 3a-3e, the fourth embodiment of a diffuser head 23 seen in FIGS. 4a-4e, and in the fifth embodiment of a diffuser head 31 seen in FIGS. 5a-5c the air outlet surface is about 2.5-3 times larger than the air inlet surface.
[0111] FIG. 11 shows a sixth embodiment of a diffuser head 43. The sixth embodiment of a diffuser head 43 is a modification of the fourth embodiment of a diffuser head 23 seen in FIGS. 4a-4e. in that the overall shape is oblong. The diffuser head 23 has been divided into diffuser head parts 23a, 23b along a plane taken along the longitudinal axis of the diffuser head 23. A longitudinal diffuser element 44 having same or different air ducts have been interposed between the diffuser head parts 23a, 23b.
[0112] None of the embodiments of a diffuser head of the present invention has air ducts that extend perpendicular to the longitudinal axis A of the respective diffuser head, as illustrated to the left in FIG. 11. All air ducts may preferably extend at an angle a less than 90° from the longitudinal axis A of a diffuser head, e.g. less than 85°, less than 80°, less than 75°, less than 75° less than 60°, less than 55°, less than 50°; less than 45°, less than 40°; less than 35°, less than 30°; less than 25°; less than 20°; less than 15°, less than 10°; or less than 5°.
[0113] The diffuser head of the present invention can have various 3D configurations. E.g. the air inlet surface and/or the air outlet surface can be oblong, such as elliptic, or just elongate, as in FIG. 11. Furthermore, several diffuser heads can be coupled to an air intake manifold, or to individual air intake tubes or hoses.
[0114] As seen in FIG. 12 of a first embodiment of a diffuser head 1 the headspace H above the air inlet surface 6 and below the upper surface or upper plane PT is substantially smaller than the total volume of the main body 9 of the first embodiment of a diffuser head 1. The same applies for all embodiments of the present invention, wherein said head space always is below 10% of the total volume delimited circumferentially by the most exterior air ducts of the plurality of air ducts; the upper plane and the air outlet surface.
Example
[0115] The cleaning apparatus shown in FIGS. 6-9 was tested with the diffuser head at a distance of 35 cm from a 32° C. warm target simulating the baby seen in FIG. 9.
[0116] The diffuser head had a diameter of 132 mm at the air inlet surface and a diameter of 168 at the air outlet surface had 313 air ducts of hexagonal cross-section. The smallest width of a hexagonal air duct is between parallel sides of the hexagon. The smallest width is at the first area A1 and is 6 mm. The third cross-sectional area A increases so that a larger outlet width is at the second area A2, which outlet width is 7.2 mm for the shortest air duct that has a length of 20 mm, and which outlet width is 8.9 mm for the longest air duct that has a length of 32 mm. As common for all embodiment of diffuser head of the present invention the length of an air duct becomes shorts the closer to the most exterior air ducts, typically gradually shorter due to lack of head space. The headspace was zero in that the air inlet surface was plane and straight.
[0117] The tubular extension had a length of 20 cm.
[0118] The pump means was a 100×25 mm centrifugal air pump bringing an air flow from the surroundings to the diffuser head at an average velocity of 0.25-0.30 m/s via a 136×32 mm HEPA filter having a pressure drop of 18 Pa.
[0119] The particle count for particles sized 0.3, 0.5, 1.0, 3.0, 5.0 and 10.0 mpi was measured both in the surrounding air as reference, and in treated air emitted by the diffuser head using an optical particle counter of type Lasair 3, 310B from Particle Measuring Systems. The results for particles sized 0.3 mpi are shown in FIG. 13.
[0120] FIG. 14 shows the air velocity at difference distances from a center axis of a diffuser head situated about 35 cm from the target. The farther away from the center axis the lower the velocity. The distance 0 corresponds to about 5 cm above the center of the target.
[0121] It can be concluded that the diffuser head of the present invention provides a clean zone without turbulence and where draft at the “border” of the clean zone is inferior. Thus the clean zone will not be noticed by the target at all. Furthermore the particle count reduction is substantial and up to at least 70% just above the target. Similar test has shown particle count reduction of 80%, and even further reduction might be possible, e.g. by change of filter means.
