WO2000012202A1

WO2000012202A1 - Arrangement for combining dissimilar streams

Info

Publication number: WO2000012202A1
Application number: PCT/US1998/017967
Authority: WO
Inventors: Laurent R. Parent; Ronald F. Gropp; Margaret E. Solomon; Russell E. Keene; Peter K. Costello
Original assignee: Kimberly-Clark Worldwide, Inc.
Priority date: 1998-08-28
Filing date: 1998-08-28
Publication date: 2000-03-09
Also published as: AU746491B2; SV1999000142A; CN1314824A; AR020352A1; BR9815994A; KR20010106455A; EP1107821B1; CO4960669A1; JP2002523228A; HK1039582A1; CN1105595C; TW457123B; DE69815403D1; AU9211298A; KR100515233B1; EP1107821A1

Abstract

An arrangement and method for effectively mixing two (or more) streams (G1, G2) of dissimilar materials is disclosed. The streams (G1, G2) may comprise two air streams of different temperatures or humidities, two streams of different gaseous materials, or even two streams of different liquids. The arrangement comprises a baffle structure (12) located within the enclosure through which is passing a first stream (G1) of material. A second stream (G2) is then injected into the enclosure at a location downstream from the baffle (12). In practicing the method of the present invention, the passage of the first stream (G1) of material across the baffle (12) results in creating a low pressure region (28) between the baffle (12) and the input port (56) of the second stream (G2). The second stream (G2) then has a natural tendency to enter this low pressure area, thus increasing the mixing efficiency with the first stream (G1) of material. The baffle (12) may comprise a tapered geometry, and multiple sets of baffles and associated input ports may be used to combine multiple streams of materials.

Description

ARRANGEMENT FOR COMBINING DISSIMILAR STREAMS

BACKGROUND OF THE INVENTION

1 . Field of the Invention

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.

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)

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

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 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

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.

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

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

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 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

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

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

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

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- 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 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. 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 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 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 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

accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Referring now to the drawings, where like numerals represent like parts in

several views:

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 ,

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

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; 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 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 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 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 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 Figure 2), is a matter of design, and provides either greater or lesser air pressure in the area therebetween, as a function of separation dL

In the embodiment as illustrated a first gas stream Gi is traveling along the length i of duct 14. Gas stream G, may comprise oxygen, nitrogen, stream, air, or any other gaseous stream. A second gas stream G₂ 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 past tapered baffle 12 creates a cavity of low pressure on the downstream side 28 of baffle 12. The path of second gas stream G₂, as shown in Figure 1 , thus enters 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 G₂ to flow outside the low pressure cavity and be swept into the flow of first gas stream G^ and thereby be evenly distributed across the face (width) of first gas stream G The turbulence created by the 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 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^; (2) modifying the aspect ratio of duct 14 (thus controlling the width and breadth of the front of the flow of gas stream G ; or (3) modifying the velocity at which second gas stream G₂ 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 1 8 of duct 14. The center of input port 24 is

illustrated as being disposed a predetermined distance d_ downstream from the

back edge 30 of baffle 1 2. 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.).

As clearly seen in this view, baffle 1 2 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,

around baffle 1 2 thus produces low pressure cavity area 32. Gas stream G₂ 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^ and G₂.

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 1 2 is formed to comprise an arc of radius r, where

this angular displacement has been found to control the overall dimensions of

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 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

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 A_L0W travels along the

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 A_HiGH 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

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

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 α, (refer to Figure 5). A particular advantage associated with this arrangement is that the injection point of stream A_H,_GH will remain above the flow path of A_L0W. Therefore, the passage of stream A_L0W will not disrupt stream A_H|GH, which will enter the low pressure region unimpeded.

Figure 6 illustrates a top view of arrangement 50. As illustrated in this particular embodiment, tapered baffle 52 includes a triangular geometry and comprises a pair of sidewalls 62 and 64 displaced by a predetermined angle θ.

Low temperature air stream A_L0W 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 A_H,_GH will naturally enter this low pressure cavity and effectively mix with stream A_L0W to form output air stream A_M,_X.

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 steady stream of A_L0W 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 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 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

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

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

material V_H (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 V_L1 (for example, an emulsifier) is introduced into enclosure 76 via a

first input port 78. Similarly, a third stream of low velocity material V_L2 (for

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 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 V_L1 and V_L2 ^{10 De} injected into a sufficient volume of enclosure 76 so as

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

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,

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 V_H would

cause first input port 78 to bend, as shown in phantom in Figure 9. The injection

path of low velocity material V_L1 is therefore perturbed, further reducing the

mixing efficiency of streams V_H and V_L1. 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 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 1 0 is a graph illustrating temperature

variation, as a function of distance, along a chamber, such as duct 14 or conduit

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°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

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

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,

measured at the same three locations B, C and D. In particular, at location B,

the temperature variation dropped from 500°F to 60°F. At location C the

variation was reduced from 320°F to 24°F and, lastly, at point D the variation

was reduced from 1 80°F to only 1 6°F. It is to be understood that these data 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.

Claims

WHAT IS CLAIMED IS:

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 h 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 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 cj. 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.

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.

1 1 . 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 1 2 wherein the first liquid stream

comprises a clear liquid and the second liquid stream comprises an emulsifier.

14. The arrangement of Claim 1 2 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.

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 cj. from the surface of the enclosure.

17. The arrangement as defined in Claim 1 6 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 1 8 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.

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.

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.

29. An arrangement for mixing a first stream of relatively low tempera┬¼

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.

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.

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.

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

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.

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┬¼

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.

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 250┬░ F and the second temperature is approximately 2440┬░ F.

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┬¼

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

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.

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 250┬░ F and the second temperature is approximately 2440┬░ F.

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

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.

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