An adsorbent package is provided for use within the sealed canister
of a fluid flow tube of an air conditioning system. The adsorbent
package includes a desiccant bag formed of a pouch having a sealed
first end and a substantially cylindrical second end. A filter cap
is slidably and sealingly received within the second end of the
pouch. The cap includes a resilient sealing ring formed proximate
a porous end wall. The sealing ring slidably and sealingly engages
an inner surface of the canister. The package is constructed of
a non-woven spun bonded nylon and can therefore be snugly received
within the tight confines of fluid flow tube or canister sections
of an integrated condenser receiver.
What is claimed is:
1. In an integrated condenser receiver apparatus of the type wherein
a fluid flow canister is juxtaposed along said apparatus for flow
of refrigerant fluid therethrough, a desiccant containing package
adapted for snug receipt within said canister, said package comprising
a pouch of non-woven spun bonded nylon material.
2. Desiccant containing package as recited in claim 1 wherein said
package is adapted for snug reception within an internal diameter
of said canister of about 18 mm-35 mm.
3. Desiccant containing package as recited in claim 2 wherein said
non-woven spun bonded nylon material has a thickness of about 3
4. Desiccant containing package as recited in claim 3 wherein said
non-woven spun bonded nylon material has a thickness of about 15
5. Desiccant containing package as recited in claim 2 wherein said
non-woven spun bonded nylon material has an air permeability of
between about 100 cfm/ft.sup.2to about 1380 cfm/ft.sup.2.
6. Desiccant containing package as recited in claim 5 wherein said
non-woven spun bonded nylon material has an air permeability of
between about 200 cfm/ft.sup.2 to 300 cfm/ft.sup.2.
7. In combination, a desiccant containing package as recited in
claim 1 and a tracer dye wafer enclosed in said package.
8. Desiccant containing package comprising an elongated pouch,
said pouch comprising a first and second end portion, one of said
first or second end portions being sealed, a cap member sealingly
received in said other end portion, said cap portion comprising
a body and a filter surface having a plurality of filter apertures
9. Desiccant containing package as recited in claim 8 wherein said
cap further comprises a sealing rim extending outwardly from said
10. Desiccant containing package as recited in claim 8 wherein
cap portion body further includes a skirt member and an attachment
ring formed around said skirt.
11. Desiccant containing package as recited in claim 10 wherein
said other end portion of said pouch is sealingly fused over said
12. Desiccant containing package as recited in claim 10 further
comprising a snap ring having an internally facing ridge member,
said other end portion of said pouch interposed between said attachment
ring and said ridge member and securely fastened to said cap thereby.
13. Desiccant containing package as recited in claim 8 wherein
said pouch is composed of a non-woven spun bonded nylon material.
14. Cap member adapted to sealingly close an open end of a pouch,
said cap comprising a generally cylindrical body having a central
axis and a filtering surface attached to said body and including
a plurality of filtering apertures therein.
15. Cap member as recited in claim 14 further comprising a sealing
rim protruding radially outwardly from said body.
16. Cap member as recited in claim 14 further including a skirt
member extending from said body and including an attachment ring
17. Combination comprising a cap member as recited in claim 16
and an annular snap ring, said snap ring including an internally
facing ridge member, said ridge member being snugly received over
said attachment ring.
18. Combination as recited in claim 17 wherein said snap ring further
comprises an inclined surface adjacent said ridge member.
 The priority benefit of U.S. Provisional Patent Application
No. 60/178595 filed Jan. 28 2000 is claimed.
BACKGROUND OF THE INVENTION
 Desiccant containing packets have been employed in small
diameter receivers that are juxtaposed along one of the condenser
headers in an integrated type condenser-receiver. These integrated
condenser-receiver structures eliminate the need for separate tubing
to connect the condenser with the receiver and have become popular
due to their reduced spatial requirements. For instance, in one
integrated condenser-receiver disclosed in U.S. Pat. No. 5813249
the overall dimensions of the integral unit are from about 300 mm-400
mm in height and about 300 mm-600 mm in width.
 In the integrated type condenser-receiver design reported
in the '249 patent, the axes of the receiver canister and associated
header are parallel with the canister attached to and contiguous
with the header. The desiccant containing package positioned in
the receiver dries refrigerant liquid (and the oil and moisture
entrained therein) prior to passage of the dried refrigerant to
a supercooler unit that is formed integrally with the condenser.
 Due to the small diameter of the receiver canister in such
integrated structures, the desiccant containing package which is
to be positioned therein must also comprise a small diameter substantially
cylindrical pouch or packet. Typically, automotive manufacturers
desire placing a fluorescent tracer dye wafer or the like in the
desiccant package so that leaks in the refrigeration system can
be readily determined by use of an ultraviolet light source. See
for instance U.S. Pat. Nos. 5149453 and 5440910.
 At present, these tracer dye wafers are available in disk
shapes having a 3/8" diameter and 3/8" thickness. Typically,
commercial felts that are used to form desiccant containing packages
are on the order of about 0.060"-0.120" in thickness.
When such conventional materials are used to form a desiccant package
for reception within these small diameter receivers, the internal
diameter and the internal cross sectional area thereof are so small
as to hinder insertion of a dye wafer therein.
 One bag used in the receiver of an integrated condenser-receiver
is fabricated by folding over the felt or other bag material and
then sewing the one edge shut, thus forming a lopsided tube. One
end of this tube is then sewn shut and the packet created by this
is filled with desiccant and then the open end is sewn shut creating
the bag. The sewn edge along the length of the bag protrudes out
from the surface and creates a hindrance to installing the bag in
a small diameter integrated receiver condenser. The construction
of the bag is labor intensive and therefore expensive to fabricate.
SUMMARY OF THE INVENTION
 We have found that a very thin, non-woven porous nylon material
may beneficially be used to form a desiccant containing package
that will fit snugly within the aforementioned small diameter receiver
or other fluid flow tube or canister of an integrated type condenser-receiver.
The thinness of the material, when formed into a cylindrical cross-sectioned
pouch or package, will allow sufficient room within the package
for insertion of a tracer dye wafer or the like therein. At the
same time, the porosity of the fabric will permit adequate fluid
permeability so that the refrigerant liquid can permeate the package
and dry upon contact with the desiccant housed therein.
 Specifically, we have found that non-woven spun bonded nylon
material available under the Cerex PBN-II designation from Cerex
Advanced Fabrics, Pensacola, Fla., is especially efficacious in
forming these small diameter desiccant packages. This material is
also sometimes referred to as being a point bonded nylon. Although
others have proposed using this particular material to form a saddle-bag
shaped absorbent unit of automotive accumulators (see file history
for U.S. Pat. No. 6038881), one artisan has opined that such use
is disfavored since allegedly the material is "difficult to
form thermally into concave configurations, had high scrap rates
and downtime, and . . . lower thermal strength." (See file
history of U.S. Pat. No. 6038881 Incovia Declaration, paragraphs
7 and 9.)
 Accordingly, it was surprising to find that this particular
non-woven material could be easily and durably formed by ultrasonic
sealing methods into a small diameter, generally cylindrical shape
so as to house desiccant and a tracer dye wafer therein. We have
found that these generally cylindrical packets are especially useful
when positioned as a desiccant package in the receiver associated
with the aforementioned integrated condenser-receiver.
 Additionally, so as to enhance the filtering efficacy of
the desiccant package, in another aspect of the invention, a solid
particle filter component and an enlarged rim area of the structure
are provided as a component of the pouch to minimize bypassing of
the desiccant containing package by refrigerant fluid and to enhance
 The present invention thus provides an adsorbent package
adapted for use in a fluid flow tube of an automotive refrigerant
system. The fluid flow tube may be, for example, an accumulator
or receiver/drier canister or the like. The fluid flow tube or canister
has a substantially cylindrical side wall and opposing first and
second end walls. An inlet opening is formed within the side wall
proximate the first end wall, while an outlet opening is formed
within the side wall proximate the second end wall.
 The adsorbent package of the present invention includes
a desiccant bag having a pouch preferably formed from a tubular
strip of non-woven spun bonded nylon material. A first end of the
pouch is sealed in a conventional manner to form an end seam. The
interior, as defined by the pouch, is then filled with an appropriate
granular adsorbent material.
 In one embodiment, the second end of the pouch slidably
and sealingly receives a filter cap. The filter cap includes a body
having a cylindrical side wall and a porous end wall which is preferably
formed integrally with the side wall. The end wall includes a plurality
of apertures sized so as to permit refrigerant fluid flow but to
restrict desiccant from passing therethrough. The cap further includes
an attachment device for securing the pouch of the desiccant bag
to the body. In one embodiment, the attachment device preferably
comprises an annular ring extending radially outwardly from the
body of the cap and positioned along a skirt portion extending from
the cap body. A resilient sealing ring is formed proximate the porous
end wall and extends radially outwardly from the body. The sealing
ring forms a living seal by slidably and sealingly engaging an inner
surface of the cylindrical side wall of the canister.
 In operation, refrigerant flows through the inlet opening
of the canister and is directed through the porous end wall of the
cap by the sealing ring. As may be appreciated, all fluid flow is
directed through the cap by sealing engagement between the sealing
ring and the cylindrical side wall of the canister. The refrigerant
flows through the cap, passing through the desiccant and pouch of
the desiccant bag. The desiccant removes moisture from the refrigerant
while the pouch filters solid particles from the refrigerant.
 The invention will be further described in conjunction with
the appended drawings and following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
 FIG. 1 is a broken away perspective view of a fluid flow
tube incorporating an adsorbent package in accordance with the present
invention, wherein the adsorbent package is shown partially exploded;
 FIG. 2 is cross-sectional view taken along the plane represented
by the lines and arrows 2-2 of FIG. 1;
 FIG. 3 is a top plan view of the adsorbent package shown
in FIG. 1;
 FIG. 4 is an exploded orthogonal view of another embodiment
of an adsorbent package in accordance with the invention;
 FIG. 5 is a magnified view of a portion of the adsorbent
package shown in FIG. 4;
 FIG. 6 is an orthogonal view of the adsorbent package shown
in FIG. 4 but prior to insertion of the integral cap and filter
 FIG. 7 is an orthogonal view of another embodiment of an
adsorbent package in accordance with the invention; and
 FIG. 8 is a schematic, fragmentary view of a portion of
an integral condenser-receiver with the adsorbent package of the
invention positioned in the receiver portion of the assembly.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
 Referring initially to FIG. 1 of the drawings, a fluid flow
tube of an air conditioning system, particularly an air conditioning
system used in the automotive field, is illustrated generally at
10. The fluid flow tube 10 comprises a conventional canister 12
including a cylindrical side wall 14 and opposing first and second
end walls 16 and 18 defining a sealed chamber 19. An inlet opening
20 is formed within the cylindrical side wall 14 proximate the second
end wall 18. Likewise, an outlet opening 22 is formed within the
side wall 14 proximate the first end wall 16. Both the inlet and
outlet openings 20 and 22 are in fluid communication with the chamber
 Referring further to FIGS. 1 and 2 the adsorbent package
24 of the present invention is received within the chamber 19 of
the canister 12. The adsorbent package 24 includes a desiccant bag
26 having a pouch 28. The pouch 28 is formed from a fluid permeable
material, preferably a non-woven spun bonded nylon as set forth
above. More particularly, the pouch 28 is preferably made from a
tubular sleeve of the spun bonded nylon material which has been
cut into lengths and filled with an appropriate granular adsorbent
material or desiccant 30.
 A first end 32 of the pouch 28 is sealed along a seam 34.
In the preferred embodiment, this end seam is formed by suitably
tucking in a portion of the tube side wall and flattening an end
portion under conditions which causes the spun bonded nylon material
to fuse together and seal the end of the pouch 28. Preferably, the
sealing is effected by use of an ultrasonic welding machine. However,
RF and heat sealing methods can also be mentioned.
 A second end 36 of the pouch 28 is substantially cylindrical
and concentrically receives a filter cap 38. The filter cap 38
in turn, is concentrically received within the side wall 14 of the
 With reference now to FIGS. 1-3 the filter cap 38 includes
a body 40 preferably molded from a thermoplastic material. The preferred
material is a polypropylene, however any similar soft pliable thermoplastic
may be readily substituted therefor. The material selected should
preferably tolerate temperatures within a range of -20.degree. to
250.degree. F. and should be compatible with the particular refrigerant
used in the air conditioning system.
 The body 40 comprises a cylindrical side wall or skirt 42
supporting a porous end wall 44. The porous end wall 44 is preferably
integrally molded with the cylindrical side wall 42 and includes
a plurality of apertures 46 (FIG. 3). The apertures 46 are sized
to have a diameter large enough to permit refrigerant flow therethrough
but small enough to prevent passage of the desiccant 30. In an alternative
embodiment of the present invention, the porous end wall 44 may
comprise a screen material fixed to the side wall 42.
 In the embodiment shown in FIGS. 1-3 an attachment device,
preferably an annular attachment ring 48 extends radially outwardly
from the skirt and is slidably received within the pouch 28 for
securing the desiccant bag 26 to the cap 38. In this embodiment
of the invention, the pouch is ultrasonically welded to the attachment
ring 48. It should be appreciated that other means of attachment,
including heat, RF, and vibration welding may be readily substituted
therefor. Alternatively, and as shown in FIG. 4 the pouch 28 may
be secured to the cap 38 by means of a mechanical fastener, such
as a snap ring.
 A sealing ring 50 extends radially outwardly from, and is
preferably integrally formed with, the body 40 proximate the end
wall 44. The sealing ring 50 is dimensioned to be concentrically
received within and sealingly engage the cylindrical side wall 14
of the canister 12. As described above, the sealing ring 50 should
be sufficiently resilient so as to provide sealing engagement with
the canister side wall 14. The sealing ring 50 provides a living
seal to prevent refrigerant flow between the end cap 38 and the
side wall 14.
 In operation, refrigerant enters the accumulator 10 through
the inlet opening 20 of the canister 12 as indicated by arrow 52
in FIG. 2. The refrigerant is directed through the apertures 46
in the porous end wall 44 by the sealing ring 50. As may be appreciated,
fluid flow is not permitted around the cap 38 due to the seal formed
between the sealing ring 50 and the canister 12.
 Refrigerant flows through the cap 38 and into the desiccant
bag 26. Moisture is removed from the refrigerant by the desiccant
30 while solid particles are filtered by the pouch 28 and apertures
46. The treated refrigerant then exits the accumulator 10 through
the outlet 22 in the canister 12 as indicated by arrow 54 in FIG.
 As may be appreciated, the present invention provides an
adsorbent package 24 which efficiently removes moisture and filters
solid particles from a refrigerant entering a fluid flow tube or
canister structure such as an accumulator or receiver/drier.
 Turning now to FIGS. 4 and 5 there is shown another embodiment
wherein an annular snap ring 102 is used to securely fasten the
top of the pouch 28 to the cap 38. Here, attachment ring 48 is provided
circumferentially around the body 40 of the cap. After the requisite
amount of desiccant is supplied to the pouch, end 36 of the pouch
28 is slidably received over the attachment ring 48. Snap ring 102
having ridge 106 formed along its internal diameter is then slid
up over the ridge or ring 48 to firmly lock the pouch within the
grasp of the engaging ridge members 106 48. In this manner, if
desired, the pouch can be snugly secured to the cap without the
need of a heat or ultrasonic sealing of the cap over the top portion
of the pouch. As shown best in FIG. 5 the ridge 106 is directly
axially above a ramp 109 or inclined surface to help ensure locking
of the ridge 106 over the attachment ring 48 that is formed on the
skirt of the cap member.
 FIG. 6 shows the pouch of FIG. 4 in position prior to filling
of the desiccant therein and, ipso facto, prior to insertion of
the cap into the end 36 of the pouch and insertion of the snap ring
102 over the body 40 of the cap. It is noted here that both a longitudinal
seam 702 and end seam 34 are provided in the strip of textile fabric
to form the open ended tubular shaped pouch shown in the drawing.
These seams, as aforementioned, are preferably formed by ultrasonic
welding means, but other sealing methods may also be used.
 FIG. 7 shows another embodiment of the invention in which
the cap and associated filter are not used. This pouch is designed
for snug, frictional engagement within the confines of a small diameter
canister of the type normally encountered in the receiver/drier
of an integrated condenser/receiver of the type described above
and wherein one particular embodiment is shown in U.S. Pat. No.
5813249. Here, in addition to seams 34 and 702 a top end seam
704 is provided to form the closed pouch structure.
 FIG. 8 is a fragmentary schematic of an integrated condenser/receiver
of the type shown in the '249 patent shown here with a small diameter
adsorbent package of the invention disposed within the receiver.
Here, condenser inlet tubes 502 communicate with the upstream section
520 of generally cylindrical header 504. The header is divided into
two sections by partition 506. Inlet 508 provides communication
for refrigerant flow from the condenser through the header 504 and
into receiver 510. As is typical in some integral condenser receiver
structures, the receiver is juxtaposed alongside the condenser header
504 and is directly connected thereto by welding, brazing, or other
conventional joining techniques.
 Quite typically, the diameter of the receiver canister is
quite small--on the order of about 18 mm-35 mm. This necessitates
that the working diameter or interior area of the desiccant containing
pouch should be such as to allow for adequate volume of desiccant
material therein, and the interior diameter of the package should
also allow for containment of a tracer dye wafer therein, without
impeding the flow of the refrigerant containing fluid therethrough.
 As shown in FIG. 8 the pouch 28 of the invention is snugly
engaged within the confines of the receiver canister. Outlet 512
provides fluid communication between the downstream end 514 of the
receiver and downstream section 522 of the header 504. The downstream
section of the header communicates with supercooler tubes 530.
 The FIG. 8 apparatus operates to permit condensed refrigerant
flow from the condenser tubes 502 into the upstream section 520
of header 504. This condensed refrigerant, carrying oil, some moisture
and possibly solids therein, flows into the upstream portion 591
of receiver 510 through inlet 508. The fluid mix then flows downstream
as shown through the filter cap 38 and desiccant bag 28 into the
downstream section 514 of the header and then into the supercooling
 As stated above, and contrary to prior indications, we have
found that the pouch 28 is advantageously formed of non-woven spun
bonded nylon material such as that sold under the previously mentioned
PBN-II designation. This material is supplied in the thickness of
from about 3 mils.-22 mils. At present, it is preferred to employ
a thickness of about 15 mils. This ensures adequate cross-sectional
area permitting dye wafer insertion into the pouch and adequate
desiccant volume and fluid permeation. Air permeability for this
material reportedly ranges from about 100 cfm/ft.sup.2 to about
1380 cfm/ft.sup.2. Air permeability of the preferred 15 mil thickness
is about 200 cfm/ft.sup.2 to 300 cfm/ft.sup.2.
 Although this invention has been described in conjunction
with certain specific forms and modifications thereof, it will be
appreciated that a wide variety of other modifications can be made
without departing from the spirit and scope of the invention.