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.2 to 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.
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, Florida, 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
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 filtering
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
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.
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 structure
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
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 canister
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
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.