AU9211298A

AU9211298A - Arrangement for combining dissimilar streams

Info

Publication number: AU9211298A
Application number: AU92112/98A
Authority: AU
Inventors: Peter K. Costello; Ronald F. Gropp; Russell E. Keene; Laurent R. Parent; Margaret E. Solomon
Original assignee: Kimberly Clark Worldwide Inc; Kimberly Clark Corp
Current assignee: Kimberly Clark Worldwide Inc
Priority date: 1998-08-28
Filing date: 1998-08-28
Publication date: 2000-03-21
Anticipated expiration: 2018-08-28
Also published as: KR100515233B1; EP1107821A1; AU746491B2; WO2000012202A1; CO4960669A1; TW457123B; EP1107821B1; AR020352A1; JP2002523228A; DE69815403D1; KR20010106455A; CN1105595C; SV1999000142A; BR9815994A; HK1039582A1; CN1314824A

Description

WO 00/12202 PCT/US98/17967 ARRANGEMENT FOR COMBINING DISSIMILAR STREAMS BACKGROUND OF THE INVENTION 1. Field of the Invention 5 The present invention relates to an arrangement and method for combining dissimilar streams and, more particularly, to a baffle configuration for utilization within a duct or similar enclosure to increase the efficiency at which two (or more) dissimilar streams of material (for example, two air streams at different temperatures) may be combined to form a homogeneous stream. 10 2. Description of the Prior Art In many industrial settings it is often necessary to combine a number of different gaseous (or liquid) materials. For example, it may be necessary to mix combustion, high temperature gases from conventional burners (gas- or oil-fired) 15 with relatively low temperature process air (as may be encountered with air dryers). Alternatively, it may be necessary to mix exhaust gas (high temperature) from the outlet of gas turbines with process air from, for example, air dryers. The structure of these arrangements typically includes a first air stream traveling through a duct (or similar enclosure), with the second stream 20 introduced into the duct via an input port. In order to effect a combination of such dissimilar streams, prior art arrangements typically relied upon the utilization of a "stirring motion" and turbulence downstream from the injection point of the second air stream. In -1 - WO 00/12202 PCT/US98/17967 general, such an arrangement requires a significant amount of energy (thus reducing the flow rate of the combined stream), as well as requiring a relatively long distance to ultimately combine the two streams and create a stream of homogeneous properties. In an alternative prior art arrangement, deflector 5 vanes are inserted downstream of the injection jet to induce counter rotational flows in the ducting. Thus, a need remains in the prior art for an improved arrangement for facilitating the combination of dissimilar streams, wherein the arrangement is both energy efficient and utilizes a minimum length of additional ducting. 10 SUMMARY OF THE INVENTION The need remaining in the prior art is addressed by the present invention which relates to an arrangement and method for combining dissimilar streams and, more particularly, to a baffle configuration for utilization within a duct or 15 similar enclosure to increase the efficiency at which two (or more) dissimilar streams of material (for example, two air streams at different temperatures) may be combined to form a homogeneous stream. In a preferred embodiment of the invention, a tapered baffle is disposed within a duct upstream of an input source for a second air stream, the second 20 air stream to be combined with a first air stream traveling through the duct. The duct is configured to comprise parallel and spaced-apart walls forming the floor and ceiling of the duct. The input port for the second stream is inserted through the floor of the duct and the baffle is tapered in a manner such that the widest -2- WO 00/12202 PCT/US98/17967 part of the baffle is nearest the input port, narrowing across the width of the duct as it approaches the ceiling of the duct. A first air stream (e.g., low temperature) is traveling through the duct and a second air stream (e.g., high temperature) is introduced via the input port. The flow of the first stream across 5 the baffle results in creating a low pressure area along the face of the baffle nearest the input port. The second stream, introduced by the input port, then naturally flows into the low pressure area created by the baffle configuration of the present invention, resulting in efficient mixing with the first stream. In an alternative embodiment of the present invention, a baffle may be 10 configured to as to include a gap area across the bottom edge of the baffle, near the floor of the duct. This embodiment is particularly well-suited for arrange ments where it is desirous to combine a low temperature air stream with a high temperature air stream. In particular, the gap allows for a stream of the low temperature air to pass underneath the baffle and be pulled into the low 15 pressure region in front of the baffle so as to provide for additional cooling of the baffle structure. The arrangement and method of the present invention may be used to combine any two dissimilar materials, for example, steam and air, low humidity air and high humidity air, nitrogen and oxygen, or even two liquids (such as a 20 clear liquid and an emulsion or suspension). In particular, the ability to combine two dissimilar streams of material (such as low temperature air and high temperature air) is extremely useful in the paper and textile industries. For example, in the fabrication of woven or knitted fabrics, as well as certain non - 3 - WO 00/12202 PCT/US98/17967 woven materials, it is necessary to "air dry" the material with a homogeneous air stream (often referred to in the art as "through air drying"). In accordance with the teachings of the present invention, the homogeneous air stream is formed by a combination of low temperature air and high temperature air 5 utilizing a baffle interposed between the air streams. In yet another embodiment of the present invention, a non-tapered baffle may be utilized to provide for the combination of two or more streams of material. In particular, a non-tapered baffle may be used in situations where a first, high velocity stream is to be combined with a second, low velocity stream. 10 In the prior art, if the low velocity stream were to be injected into the path of the high velocity stream, the input port of the low velocity stream could become strained, thus misdirecting the flow of low velocity material across the floor of the duct, resulting in inefficient mixing. In accordance with the teachings of the present invention, a baffle configured as a non-tapered plate functions to shield 15 the input port from the path of the high velocity stream. Thus, the low velocity material is able to extend across the width of the duct, resulting in more efficient mixing downstream. In a further embodiment of the present invention, a plurality of dissimilar streams may be combined to form one, homogeneous stream by utilizing a 20 plurality of separate baffles, each baffle being disposed upstream of one of a plurality of input ports. The plurality of input ports may be disposed in any desired location with respect to the enclosure. For example, the ports may be positioned along the length of the enclosure or, alternatively, may be positioned -4- WO 00/12202 PCT/US98/17967 across the width of the enclosure. Additionally, the baffle may comprise a solid piece of material or, alternatively, may include one or more perforations. These and other embodiments of the present invention will become apparent during the course of the following discussion and by reference to the 5 accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS Referring now to the drawings, where like numerals represent like parts in several views: 10 Figure 1 illustrates a view in perspective of an exemplary embodiment of the mixing arrangement of the present invention; Figure 2 contains a view of the arrangement of Figure 1, taken along line 2-2; Figure 3 contains an alternative view of the arrangement of Figure 1, 15 taken along line 3-3; Figure 4 illustrates an alternative embodiment of the present invention, including a gapped baffle; Figure 5 is a view of the arrangement of Figure 4 taken along line 5-5; Figure 6 is an alternative view of the arrangement of Figure 4, taken along 20 line 6-6; Figure 7 is a view of the arrangement of Figure 5, taken along line 7-7, illustrating in particular the gap area included within the exemplary baffle structure; -5- WO 00/12202 PCT/US98/17967 Figure 8 illustrates, in a perspective view, an alternative arrangement of the present invention utilizing a plurality of baffles and associated input ports; Figure 9 contains a side view of the arrangement of Figure 8, taken along line 9-9 of Figure 8; and 5 Figure 10 is a graph illustrating the results achieved utilizing the arrangement of the present invention as compared with a prior art arrangement, in particular, the improvement in temperature "mixing" achieved when combining low temperature air with high temperature air. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 10 Figure 1 illustrates an exemplary mixing arrangement 10 of the present invention. As shown, the arrangement comprises a tapered baffle 12 disposed in a duct 14 such that widest edge 16 of baffle 12 is in proximity with bottom wall 18 of duct 14. Baffle 12 then tapers into a point 20 in the proximity of top wall 22 of duct 14. It is to be understood that while duct 14 of this 15 embodiment is illustrated as comprising a rectangular cross-section, any suitable enclosure of any predetermined geometry may be utilized. Additionally, the geometry of baffle 12 may differ in particular circumstances. For the arrangement of Figure 1, baffle 12 is illustrated as comprising a conic section. Other tapered or non-tapered configurations may be utilized and fall within the 20 spirit and scope of the present invention. Input port 24 protrudes through bottom wall 18 of duct 14 and is located downstream (with respect to the direction of the flow through duct 14) of baffle 12. The distance d between the center of input port 24 and baffle 12 (shown in -6- WO 00/12202 PCT/US98/17967 Figure 2), is a matter of design, and provides either greater or lesser air pressure in the area therebetween, as a function of separation d. In the embodiment as illustrated a first gas stream G 1 is traveling along the length I of duct 14. Gas stream G 1 may comprise oxygen, nitrogen, stream, 5 air, or any other gaseous stream. A second gas stream G 2 travels through tubing 26 and is introduced into duct 14 via input port 24. In accordance with the teachings of the present invention, the flow of first gas stream G 1 past tapered baffle 12 creates a cavity of low pressure on the downstream side 28 of baffle 12. The path of second gas stream G 2 , as shown in Figure 1, thus enters 10 the low pressure area. The natural tendency of the jet of injected gas to broaden with increasing distance from the injection point thus causes increasing amounts of second gas stream G 2 to flow outside the low pressure cavity and be swept into the flow of first gas stream G 1 and thereby be evenly distributed across the face (width) of first gas stream G 1 . The turbulence created by the 15 tapered baffle structure thus contributes to spreading the mixing action across the front of the flow of first gas stream G,. It is to be understood that the mixing of the present invention achieved by the utilization of the tapered baffle can be further enhanced by any of the following attributes: (1) modifying the cross section area of duct 12 so as to 20 control the velocity of gas stream G, (e.g., decreasing the cross section of duct 14 in the region of baffle 12 and input port 24 will increase the velocity of gas stream G 1 ); (2) modifying the aspect ratio of duct 14 (thus controlling the width and breadth of the front of the flow of gas stream G 1 ); or (3) modifying the -7- WO 00/12202 PCT/US98/17967 velocity at which second gas stream G 2 exits input port 24. Figure 2 illustrates a side view of the arrangement described above in Figure 1. As shown in this view, input port 24 protrudes a predetermined height h through bottom surface 18 of duct 14. The center of input port 24 is 5 illustrated as being disposed a predetermined distance d downstream from the back edge 30 of baffle 12. Both the height h and the distance d can be controlled so as to provide the most efficient mixing of the two streams, wherein these parameters will be function of the various conditions associated with the two streams (e.g., temperature, composition, humidity, flow rate, etc.). 10 As clearly seen in this view, baffle 12 is sized such that top point 20 does not come into contact with top surface 22 of duct 14. The flow of gas stream G 1 around baffle 12 thus produces low pressure cavity area 32. Gas stream G 2 as it exits input port 24 thus naturally tends to enter cavity 32 and results in increased efficiency in the mixing of gas streams G 1 and G 2 . 15 As mentioned above, another factor that effects the efficiency of the arrangement of the present invention is the geometry of the baffle. Figure 3 illustrates a top view in perspective of the mixing arrangement of Figure 1. As shown, sidewall 34 of baffle 12 is formed to comprise an arc of radius r, where this angular displacement has been found to control the overall dimensions of 20 low pressure cavity 32, as well as the actual pressure within the cavity area. One particular environment for the utilization of the method of the present invention, as mentioned above, is the "through air" drying process associated with the fabrication of woven and non-woven fabrics, where it is often -8- WO 00/12202 PCT/US98/17967 necessary to combine low temperature and high temperature air streams. Figure 4 illustrates a particular embodiment of the present invention that is well-suited to such an environment. This environment is suitable for treating light-weight, soft paper products including those having a basis weight of less than 5 and 5 greater than 200 grams per square meter. In particular, mixing arrangement 50 comprises a baffle 52 disposed in a conduit (or similar enclosure) 54, where baffle 52 is located upstream (with respect to the direction of flow through conduit 54) a predetermined distance d (illustrated in Figure 5) from an input port 56. As shown, a first stream of low temperature air ALOW travels along the 10 length of conduit 54 and impinges upon baffle 52 so as to create a low pressure cavity 56 in the interior region of baffle 52. A second stream of high temperature air AHIGH travels through tubing 58 and enters conduit 54 via input port 56. For this particular low temperature/high temperature embodiment of the present invention, baffle 52 includes a lower gap area formed by displacing 15 the bottom surface 58 of baffle 52 a predetermined gap distance g (illustrated in Figure 5) from lower surface 60 of conduit 54. As also seen in Figure 4, baffle 52 includes a number of perforations 53, where these perforations serve to "cool" baffle 52 by allowing a larger quantity of low temperature air to pass therethrough. It is to be understood that the number and size of the 20 perforations should be limited so as to not disrupt the low pressure region created by the baffle structure. Another feature of this particular embodiment is that input port 56 protrudes into conduit 54 a height h greater than the gap distance g (refer to Figure 5). A particular advantage associated with this -9- WO 00/12202 PCT/US98/17967 arrangement is that the injection point of stream AHIGH will remain above the flow path of ALOW. Therefore, the passage of stream ALOW will not disrupt stream AHIGH, which will enter the low pressure region unimpeded. Figure 6 illustrates a top view of arrangement 50. As illustrated in this 5 particular embodiment, tapered baffle 52 includes a triangular geometry and comprises a pair of sidewalls 62 and 64 displaced by a predetermined angle 0. Low temperature air stream ALOW travels past baffle 52 so as to create a low pressure region 66 between input port 56 and baffle 52. Therefore, high temperature air stream AHIGH will naturally enter this low pressure cavity and 10 effectively mix with stream ALOW to form output air stream AMIx. Figure 7 contains a perspective view of the arrangement of Figure 5, taken along line 7-7. Evident in this view is the gap area 55 between baffle and lower surface 60 of conduit 54. As shown, only small leg portions 57,59 of baffle 52 are in contact with surface 60 (for stability purposes), allowing for a 15 steady stream of ALOW to pass through gap area 55 and provide cooling to baffle 52. As mentioned above, the utilization of a baffle arrangement in accordance with the present invention may be particularly advantageous in situations where it is necessary to inject a low velocity stream into the path of a high velocity 20 stream. Figure 8 illustrates one such arrangement of the present invention that is particularly well-suited for this purpose. Additionally, Figure 8 illustrates an arrangement including a pair of baffles and associated input ports since, as discussed earlier, the technique of the present invention may be extended to - 10- WO 00/12202 PCT/US98/17967 provide for the combining of any number of dissimilar materials. Indeed, although only two exemplary baffles and associated input ports are illustrated, it is to be understood that any desired number of such baffles and associated input ports may be utilized and fall within the spirit and scope of the present 5 invention. Additionally, in accordance with the teachings of the present invention, the multiple baffle/port arrangements may be disposed in any desired fashion within the enclosure. For example, they may be positioned along the length of the enclosure or, alternatively, across the width of the enclosure, or any suitable combination. In general, their location within the enclosure (as long 10 as the baffle is disposed upstream of its associated input port) is not relevant to the teachings of the present invention. Referring in particular to Figure 8, arrangement 70 includes a first baffle plate 72 and a second baffle plate 74, each baffle plate being disposed to extend across the width of an enclosure 76. A first stream of high velocity 15 material VH (for example, a clear liquid) is traveling through enclosure 76 such that it first impinges and passes over first baffle plate 72, subsequently striking and passing over second baffle plate 74. A second stream of low velocity material VL1 (for example, an emulsifier) is introduced into enclosure 76 via a first input port 78. Similarly, a third stream of low velocity material VL 2 (for 20 example, an emulsifier of a different composition and/or velocity) is introduced into enclosure 76 via a second input port 80. In accordance with the teachings of the present invention, each input port is located a predetermined distance downstream of its associated baffle plate. As with the other embodiments -11 - WO 00/12202 PCT/US98/17967 discussed above, arrangement 70 allows for the formation of low pressure areas in the region between each baffle plate and its associated input port. Thus, in this particular embodiment, the low pressure areas allow for low velocity streams VL1 and VL 2 to be injected into a sufficient volume of enclosure 76 so as 5 to result in efficient mixing. Additionally, as shown in Figure 8, any baffle structure of the present invention may be formed as a multiple unit structure, with the capability to add or remove separate units to effect different results. For example, a second baffle section 82 may be attached to the top portion of first baffle plate 72, where second section 82 would allow for the baffle 10 structure to perform with even higher velocity materials. It is to be understood therefore, that the baffle size and shape may be adjusted, over time, to accommodate for various velocities of materials, where the adjustment may best be accomplished by utilizing a multiple unit baffle structure. Figure 9 contains a cut-away side view of arrangement 70 of Figure 8, 15 taken along line 9-9. As previously discussed, the utilization of a baffle in situations where a low velocity stream is injected into a high velocity flow is particularly advantageous. In a conventional arrangement without the baffle structure of the present invention, the force of high velocity stream VH would cause first input port 78 to bend, as shown in phantom in Figure 9. The injection 20 path of low velocity material VL1 is therefore perturbed, further reducing the mixing efficiency of streams VH and VL1. Therefore, utilization of baffle plate 72 in accordance with the teachings of the present invention acts as a physical barrier between the high velocity stream and the input port, allowing the low -12- WO 00/12202 PCT/US98/17967 velocity material to be injected in the desired direction. A numerical depiction of the effectiveness of the present invention is included in Figure 10. In particular, Figure 10 is a graph illustrating temperature variation, as a function of distance, along a chamber, such as duct 14 or conduit 5 54, when utilizing the arrangement of the present invention to combine to air streams of different temperatures. For the results as illustrated in Figure 9, a first stream of air having an ambient temperature of 250 0 F is to be combined with a second stream of air having an ambient temperature of 2440'F. The efficiency of the combination of the air streams may be measured by assessing 10 the temperature variation at any point downstream of the point at which the two streams begin to combine. The graph in Figure 10 includes measurements of this temperature variation at three separate locations - a first point B at a distance of 575 inches beyond the location of the input port for the high temperature stream, a second point C at a distance of 779 inches beyond the 15 input port, and a third point D, a distance of 983 inches beyond the input port. The temperature variations associated with a convention, prior art structure are indicated as circles in Figure 9. The improvement in mixing efficiency associated with utilization the baffle arrangement of the present invention is evident from viewing the temperature variations, indicated as triangles, 20 measured at the same three locations B, C and D. In particular, at location B, the temperature variation dropped from 500'F to 60 0 F. At location C the variation was reduced from 320'F to 24 0 F and, lastly, at point D the variation was reduced from 180 0 F to only 16 0 F. It is to be understood that these data -13- WO 00/12202 PCT/US98/17967 points represent temperature variations (as a function of location across the width of the enclosure at the associated point), not the actual ambient temperature of the mixed air stream. -14-

Claims

1. An arrangement for combining a first stream of material traveling through an enclosure with a second stream of material, said second stream of material comprising different characteristics than said first stream, said arrangement comprising: an input port for introducing said second stream into said enclosure wherein said port protrudes a predetermined height b into said enclosure; and a baffle disposed within said enclosure and positioned to intersect said first stream at a location upstream of said input port, said baffle being separated from said input port by a predetermined distance d, wherein the passage of said first stream across said baffle creates a region of low pressure between said baffle and said input port sufficient to increase the efficiency of the combining of said first and second streams.

2. The arrangement as defined in Claim 1 wherein the baffle comprises a tapered structure configured to include a relatively wide bottom portion and a relatively narrow top portion, said tapered baffle being disposed such that said relatively wide bottom portion is located nearest the input port and the tapered baffle extends across the width of the enclosure.

3. The arrangement as defined in Claim 2 wherein the baffle is tapered such that the relatively narrow top portion of said baffle does not contact the 15 WO 00/12202 PCT/US98/17967 enclosure.

4. The arrangement as defined in Claim 2 wherein the tapered baffle comprises a conic section geometry.

5. The arrangement as defined in Claim 2 wherein the tapered baffle comprises a triangular geometry.

6. The arrangement as defined in Claim 2 wherein the relatively wide bottom portion of the tapered baffle includes a gap area such that a portion of said relatively wide bottom portion is displaced a predetermined gap distance g from the surface of the enclosure.

7. The arrangement as defined in Claim 6 wherein the input port is disposed to protrude within the enclosure a predetermined height h greater than the gap g associated with the tapered baffle.

8. The arrangement as defined in Claim 7 wherein the first stream comprises relatively low temperature air and the second stream comprises relatively high temperature air, the gap in said tapered baffle thereby allowing said relatively low temperature air to pass under said baffle, enter the region of low pressure and reduce the ambient temperature of said baffle. 16 WO 00/12202 PCT/US98/17967

9. The arrangement as defined in Claim 8 wherein the tapered baffle includes one or more perforations so as to provide additional cooling to said tapered baffle.

10. The arrangement as defined in Claim 1 wherein the first stream comprises a first gaseous material and the second stream comprises a second gaseous material.

11. The arrangement of Claim 10 wherein the first gas is nitrogen and the second gas is oxygen.

12. The arrangement of Claim 1 wherein the first material is a first liquid and the second material is a second liquid.

13. The arrangement of Claim 12 wherein the first liquid stream comprises a clear liquid and the second liquid stream comprises an emulsifier.

14. The arrangement of Claim 12 wherein the first liquid stream comprises a clear liquid and the second liquid stream comprises a suspension.

15. The arrangement as defined in Claim 1 wherein the baffle includes one or more perforations. 17 WO 00/12202 PCT/US98/17967

16. The arrangement as defined in Claim 1 wherein the baffle includes a gap area such that an edge of said baffle nearest the input port is displaced a predetermined gap distance g from the surface of the enclosure.

17. The arrangement as defined in Claim 16 wherein the input port is disposed to protrude within the enclosure a predetermined height h greater than the gap g associated with the displacement of the edge of the baffle.

18. The arrangement as defined in Claim 1 wherein the first stream comprises a high velocity stream and the second stream comprises a low velocity stream.

19. The arrangement as defined in Claim 18 wherein the baffle comprises a non-tapered plate geometry.

20. The arrangement as defined in Claim 1 wherein the baffle comprises a non-tapered plate geometry.

21. The arrangement as defined in Claim 1 wherein the baffle comprises a unitary piecepart. 18 WO 00/12202 PCT/US98/17967

22. The arrangement as defined in Claim 1 wherein the baffle comprises multiple pieceparts such that separate sections may be added or removed as desired.

23. The arrangement as defined in Claim 20 wherein the baffle comprises a lower plate section and an upper plate section removably attached to said lower plate section.

24. An arrangement for combining a first stream of material traveling through an enclosure with a plurality of dissimilar streams of material, each stream of said plurality of dissimilar streams comprising different characteristics than said first stream, said arrangement comprising: a plurality of input ports disposed to protrude into the enclosure, each input port for introducing a separate one of the plurality of dissimilar streams; and a plurality of baffles, said plurality of baffles being associated in a one-to one relationship with said plurality of input ports, each baffle being disposed upstream from its associated input port and separated therefrom by a predetermined distance d, wherein the passage of said first stream across each baffle of said plurality of baffles creates a region of low pressure between each baffle and its associated input port sufficient to increase the efficiency of the combining of said first stream and said plurality of dissimilar streams. 19 WO 00/12202 PCT/US98/17967

25. The arrangement as defined in Claim 24 wherein at least one baffle of the plurality of baffles comprises a tapered structure configured to include a relatively wide bottom portion and a relatively narrow top portion, said at least one tapered baffle being disposed such that said relatively wide bottom portion is located nearest the associated at least one input port and said at least one tapered baffle extends across the width of the enclosure.

26. The arrangement as defined in Claim 25 wherein the at least one baffle is tapered such that the relatively narrow top portion does not contact the enclosure.

27. The arrangement as defined in Claim 24 wherein the plurality of input ports are disposed along the length of the enclosure.

28. The arrangement as defined in Claim 24 wherein the plurality of input ports are disposed across the width of the enclosure. 20 WO 00/12202 PCT/US98/17967

29. An arrangement for mixing a first stream of relatively low tempera ture air traveling through a duct with a second stream of relatively high temperature air, the arrangement comprising: an input port disposed to protrude into the duct, said input port for introducing the second stream into said duct; and a tapered baffle disposed in said duct to intercept the flow of said first stream, wherein said tapered baffle is located a predetermined distance d upstream from said input port, said tapered baffle comprising a relatively wide bottom surface and sidewalls narrowing along their length to form a tapered top region, said baffle being disposed such that the wide bottom surface is in proximity with the portion of said duct through which said input port protrudes, said tapered baffle then extending across the width of said duct. 21 WO 00/12202 PCT/US98/17967

30. A method of combining a first stream of material with a second stream of material, said second stream of material comprising different characteristics than said first stream, said method comprising the steps of: a) introducing the first stream into an enclosure such that said first stream travels along the length of the enclosure; b) interrupting the flow of said first stream using a baffle disposed within the enclosure; and c) introducing the second stream into said enclosure, said second stream being introduced at a location downstream of said baffle, the interruption of the flow of said first stream across said baffle creating a region of low pressure between said baffle and the introduction of said second stream sufficient to increase the efficiency of the combining of said first and second streams.

31. The method according to Claim 30 wherein the first stream comprises relatively low temperature air and the second stream comprises relatively high temperature air.

32. The method according to Claim 30 wherein the first stream comprises a first gaseous material and the second stream comprises a second gaseous material. 22 WO 00/12202 PCT/US98/17967

33. The method according to Claim 32 wherein the first gas is nitrogen and the second gas is oxygen.

34. The method according to Claim 30 wherein the first material is a first liquid and the second material is a second liquid.

35. The method according to Claim 30 wherein the first stream comprises a high velocity stream and the second stream comprises a low velocity stream. 23 WO 00/12202 PCT/US98/17967

36. A method of combining a plurality of streams of dissimilar materials, said method comprising the steps of: a) introducing a first stream into an enclosure such that said first stream travels along the length of the enclosure; b) interrupting the flow of said first stream using a baffle disposed within the enclosure; and c) introducing a second stream into said enclosure, said second stream being introduced at a location downstream of said baffle, the interruption of the flow of said first stream across said baffle creating a region of low pressure between said baffle and the introduction of said second stream sufficient to increase the efficiency of the combining of said first and second streams; and d) repeating steps b) and c) for each stream remaining in the plurality of dissimilar streams until all streams have been combined. 24 WO 00/12202 PCT/US98/17967

37. In the fabrication of woven material, a method of drying the woven material by subjecting said woven material to a stream of essentially tempera ture invariant air comprising the steps of: a) inserting the woven material into a suitable drying apparatus; and b) applying a stream of essentially temperature invariant air to the surface of said woven material, the stream of essentially temperature invariant air formed by c) introducing a first stream of air at a first temperature into an enclosure such that said first stream travels along the length of the enclosure; d) interrupting the flow of said first stream using a baffle disposed within the enclosure; and e) introducing a second stream of air at a second temperature different than said first temperature into said enclosure, said second stream being introduced at a location downstream of said baffle, the interruption of the flow of said first stream across said baffle creating a region of low pressure between said baffle and the introduction of said second stream sufficient to increase the efficiency of the combining of said first and second streams and provide as an output the essentially temperature invariant air stream used to dry said woven material. 25 WO 00/12202 PCT/US98/17967

38. The method as defined in Claim 37 wherein the first air stream comprises a relatively low temperature and the second air stream comprises a relatively high temperature.

39. The method as defined in Claim 38 wherein the first temperature is approximately 2500 F and the second temperature is approximately 24400 F. 26 WO 00/12202 PCT/US98/17967

40. In the fabrication of knitted material, a method of drying the knitted material by subjecting said knitted material to a stream of essentially tempera ture invariant air comprising the steps of: a) inserting the knitted material into a suitable drying apparatus; and b) applying a stream of essentially temperature invariant air to the surface of said knitted material, the stream of essentially temperature invariant air formed by c) introducing a first stream of air at a first temperature into an enclosure such that said first stream travels along the length of the enclosure; d) interrupting the flow of said first stream using a baffle disposed within the enclosure; and e) introducing a second stream of air at a second temperature different than said first temperature into said enclosure, said second stream being introduced at a location downstream of said baffle, the interruption of the flow of said first stream across said baffle creating a region of low pressure between said baffle and the introduction of said second stream sufficient to increase the efficiency of the combining of said first and second streams to provide as an output the essentially temperature invariant air stream applied to dry said knitted material. 27 WO 00/12202 PCT/US98/17967

41. The method as defined in Claim 40 wherein the first air stream comprises a relatively low temperature and the second air stream comprises a relatively high temperature.

42. The method as defined in Claim 41 wherein the first temperature is approximately 2500 F and the second temperature is approximately 24400 F. 28 WO 00/12202 PCT/US98/17967

43. In the fabrication of non-woven material, a method of drying the non woven material by subjecting said non-woven material to a stream of essentially temperature invariant air comprising the steps of: a) inserting non-woven material having a basis weight either one of less than 5 grams per square meter and greater than 200 grams per square meter into a suitable drying apparatus; and b) applying a stream of essentially temperature invariant air to the surface of said non-woven material, the stream of essentially temperature invariant air formed by c) introducing a first stream of air at a first temperature into an enclosure such that said first stream travels along the length of the enclosure; d) interrupting the flow of said first stream using a baffle disposed within the enclosure; and e) introducing a second stream of air at a second temperature different than said first temperature into said enclosure, said second stream being introduced at a location downstream of said baffle, the interruption of the flow of said first stream across said baffle creating a region of low pressure between said baffle and the introduction of said second stream sufficient to increase the efficiency of the combining of said first and second streams and provide as an output the essentially temperature invariant air stream applied to dry said non woven material. 29 WO 00/12202 PCT/US98/17967

44. The method as defined in Claim 43 wherein the first air stream comprises a relatively low temperature and the second air stream comprises a relatively high temperature.

45. The method as defined in Claim 44 wherein the first temperature is approximately 2500 F and the second temperature is approximately 24400 F. 30