Abstrict A receiver-dryer for use in an air conditioning system utilizes
desiccant bags that can be mounted within the receiver-dryer body
without using mounting plates or baffles. The receiver-dryer includes
an output tube having a retaining shoulder located thereon. In one
embodiment, a desiccant bag includes a rigid eyelet that cooperates
with the retaining shoulder to support the desiccant bag. In an
alternate embodiment, the desiccant bag is supported by the retaining
shoulder via a support washer.
Claims We claim:
1. A receiver-dryer assembly for use in a heat exchanging system,
said receiver-dryer assembly comprising:
a body defining an interior volume;
an inlet duct for directing flow of refrigerant into said interior
volume;
an outlet duct for directing flow of refrigerant out from said
interior volume;
an outlet tube in fluid communication with said outlet duct and
residing within said interior volume;
a desiccant bag located in a flow path of said refrigerant through
said body, said desiccant bag having:
a shell formed from a porous material, said shell having a mounting
hole formed therein;
a quantity of desiccant material located within said shell; and
a substantially rigid eyelet coupled to said shell and located
around said mounting hole, said eyelet being configured to receive
said outlet tube; and
a retaining shoulder located on said outlet tube, said retaining
shoulder being in contact with said eyelet and configured to support
said eyelet to limit movement of said desiccant bag toward a lower
end of said body.
2. A receiver-dryer assembly according to claim 1 wherein said
shell comprises:
a filter lid having said mounting hole formed therein and said
eyelet coupling to said filter lid; and
a filter bag coupled to said filter lid around the outer periphery
thereof and around said mounting hole to hold said desiccant material
therein, said filter bag extending below said filter lid toward
said lower end of said body.
3. A receiver-dryer assembly according to claim 2 wherein:
said filter lid has an exposed upper surface;
a portion of said eyelet resides below said upper surface; and
said eyelet is sized such that said retaining shoulder supports
said eyelet.
4. A receiver-dryer assembly according to claim 1 further comprising
a second desiccant bag maintained on said outlet tube above said
desiccant bag, said second desiccant bag comprising:
a second shell formed from a porous material, said second shell
having a second mounting hole formed therein; and
a second quantity of desiccant material located within said second
shell.
5. A receiver-dryer assembly according to claim 4 wherein:
said inlet duct and said outlet duct are located at an upper end
of said body;
said outlet tube extends from said upper end toward a lower end
of said body; and
said retaining shoulder is positioned on said outlet tube such
that said desiccant bag supports said second desiccant bag proximate
said upper end.
6. A receiver-dryer assembly according to claim 4 wherein said
second desiccant bag further comprises a second substantially rigid
eyelet coupled to said second shell and located around said second
mounting hole, said second eyelet being configured to receive said
outlet tube.
7. A receiver-dryer assembly according to claim 4 further comprising
a receiving block that locates said outlet tube within said interior
volume, wherein:
the outer diameter of said second eyelet is approximately equal
to or greater than the outer diameter of said receiving block; and
said retaining shoulder is positioned on said outlet tube such
that said desiccant bag supports said second desiccant bag and said
second eyelet abuts said receiving block.
8. A receiver-dryer assembly for use in a heat exchanging system,
said receiver-dryer assembly comprising:
a body defining an interior volume;
an inlet duct for directing flow of refrigerant into said interior
volume;
an outlet duct for directing flow of refrigerant out from said
interior volume;
an outlet tube in fluid communication with said outlet duct and
residing within said interior volume;
a desiccant bag located in a flow path of said refrigerant through
said body, said desiccant bag having a shell formed from a porous
material, a mounting hole formed in said shell and configured to
receive said outlet tube, and a quantity of desiccant material located
within said shell;
a retaining shoulder located on said outlet tube; and
a support washer located between and in contact with each of said
retaining shoulder and said shell, said support washer being configured
to support said desiccant bag above a lower end of said body.
9. A receiver-dryer assembly according to claim 8 wherein said
shell comprises:
a filter lid having said mounting hole formed therein; and
a filter bag coupled to said filter lid around the outer periphery
thereof and around said mounting hole to hold said desiccant material
therein.
10. A receiver-dryer assembly according to claim 9 wherein said
filter bag extends below said filter lid toward said lower end of
said body, said filter bag surrounding said support washer.
11. A receiver-dryer assembly according to claim 8 further comprising
a second desiccant bag maintained on said outlet tube above said
desiccant bag, said second desiccant bag comprising:
a second shell formed from a porous material, said second shell
having a second mounting hole formed therein; and
a second quantity of desiccant material located within said second
shell.
12. A receiver-dryer assembly according to claim 11 wherein:
said inlet duct and said outlet duct are located at an upper end
of said body;
said outlet tube extends from said upper end toward a lower end
of said body; and
said retaining shoulder is positioned on said outlet tube such
that said desiccant bag supports said second desiccant bag proximate
said upper end.
13. A receiver-dryer assembly according to claim 11 further comprising:
a receiving block that locates said outlet tube within said interior
volume; and
a second support washer located between said receiving block and
said second desiccant bag; wherein:
the outer diameter of said second support washer is approximately
equal to or greater than the outer diameter of said receiving block;
and
said retaining shoulder is positioned on said outlet tube such
that said desiccant bag supports said second desiccant bag and such
that said second support washer abuts said receiving block.
14. A receiver-dryer assembly according to claim 11 further comprising:
a receiving block that locates said outlet tube within said interior
volume;
a substantially rigid eyelet coupled to said second shell and located
around said second mounting hole, said eyelet being configured to
receive said outlet tube; wherein:
the outer diameter of said eyelet is approximately equal to the
outer diameter of said receiving block; and
said retaining shoulder is positioned on said outlet tube such
that said desiccant bag supports said second desiccant bag and such
that said eyelet abuts said receiving block.
Description BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to air conditioning systems.
More particularly, the present invention relates to receiver-dryers
and desiccant bags utilized in air conditioning systems.
2. The Prior Art
Receiver-dryers are employed by air conditioning systems to remove
water and to filter impurities from the refrigerants that circulate
through the air conditioning systems. Porous bags filled with desiccant
matter (desiccant bags) are frequently used to perform contaminant
filtration and water absorption in receiver-dryers. Alternatively,
at least one known receiver-dryer includes loose particles of desiccant
sandwiched between upper and lower filtration plates. Unfortunately,
it can be difficult and time consuming to assemble a receiver-dryer
that utilizes such prior art desiccant elements.
A conventional receiver-dryer typically includes a hollow body
that receives an inward flow of refrigerant and an output tube that
carries the treated refrigerant out of the body. In a cylindrical
receiver-dryer body, the output tube is centrally positioned such
that it extends downward from an output duct located at the top
of the body. A donut-shaped desiccant bag resides on the output
tube and is located within the body such that the refrigerant passes
through the desiccant bag en route to the output tube.
Conventional desiccant bags are formed from porous, flexible fabric
and, consequently, they lack an appreciable amount of structural
rigidity near their mounting holes and near their peripheral edges.
One known receiver-dryer utilizes upper and lower baffles to maintain
the desiccant bag (or bags) in a predetermined location along the
output tube. In addition, the baffles themselves are secured within
the body via snap rings, clips, or other fastening elements. Consequently,
such receiver-dryers can be difficult to assemble and the associated
manufacturing costs can be undesirably high.
SUMMARY OF THE INVENTION
Accordingly, it is an advantage of the present invention that an
improved receiver-dryer for use in an air conditioning system is
provided.
Another advantage of the present invention is that an improved
desiccant bag for use in a receiver-dryer is provided.
Another advantage is that the present invention provides a receiver-dryer
that is easy to manufacture and assemble.
A further advantage of the present invention is that it provides
a desiccant bag that can be mounted within a receiver-dryer body
without the use of mounting plates.
Another advantage is that a desiccant bag with improved structural
rigidity is provided by the present invention.
The above and other advantages of the present invention are carried
out in one form by a receiver-dryer assembly having a body defining
an interior volume, a refrigerant inlet duct, a refrigerant outlet
duct, an outlet tube residing within the interior volume, a desiccant
bag located in a refrigerant flow path through the body, and a retaining
shoulder located on the outlet tube. The desiccant bag includes
a shell formed from a porous material, a mounting hole formed in
the shell, desiccant material located within the shell, and a substantially
rigid eyelet coupled to the shell and located around the mounting
hole. The retaining shoulder cooperates with the eyelet to limit
movement of the desiccant bag toward a lower end of the body.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete understanding of the present invention may be derived
by referring to the detailed description and claims when considered
in connection with the Figures, wherein like reference numbers refer
to similar items throughout the Figures, and:
FIG. 1 is a cross sectional view of a receiver-dryer assembly according
to a first embodiment of the present invention;
FIG. 2 is a perspective view of a desiccant bag utilized in the
receiver-dryer assembly shown in FIG. 1;
FIG. 3 is a cross sectional view of the desiccant bag viewed from
line 3--3 in FIG. 2; and
FIG. 4 is a cross sectional view of a receiver-dryer assembly according
to a second embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1 a cross sectional view of a receiver-dryer
assembly 10 according to a first preferred embodiment of the present
invention is illustrated. Receiver-dryer assembly 10 is used in
a heat exchanging system, such as an automotive air conditioning
system (not shown), to remove water and impurities from the refrigerant
that circulates through the system. Receiver-dryers and air conditioning
systems in general are well known to those skilled in the art.
Receiver-dryer assembly 10 includes a hollow body 12 defining an
interior volume 14 through which refrigerant flows during operation
of the air conditioning system. In the preferred embodiment, body
12 is substantially cylindrical with a conically-tapered lower end
16. Body 12 may be formed from any material suitable for carrying
the refrigerants and oils typically used in air conditioning systems,
e.g., aluminum. A cover plate 18 is located at an upper end 20 of
body 12. Cover plate 18 is sealed to body 12 to prevent leakage
of the refrigerant.
An inlet duct 22 is formed within cover plate 18 to direct the
flow of refrigerant into interior volume 14. The direction of flow
is indicated by the arrows in FIG. 1. Inlet duct 22 may be configured
to receive any number of conventional fittings for fluid connection
to the remainder of the air conditioning system.
In the embodiment shown in FIG. 1 receiver-dryer assembly 10 utilizes
two similar desiccant bags 24 through which refrigerant flows during
operation of the air conditioning system. Desiccant bags 24 are
located in the flow path of the refrigerant through body 12 and
are preferably arranged in a stacked relationship within interior
volume 14. Desiccant bags 24 are configured to absorb excess water
and remove unwanted impurities from the refrigerant. Desiccant bags
24 are described in more detail below.
After the refrigerant passes through desiccant bags 24 it enters
an outlet tube 26. Outlet tube 26 is coupled to cover plate 18 and
is in fluid communication with an outlet duct 28 formed in cover
plate 18. As shown, outlet tube 26 extends from upper end 20 toward
lower end 16 and is adapted to centrally reside within interior
volume 14. Refrigerant flows upward through outlet tube 26 and into
outlet duct 28 which directs the flow of refrigerant out from interior
volume 14. As with inlet duct 22 outlet duct 28 may be configured
to receive suitable fittings for connection to the air conditioning
system.
Outlet tube 26 fits into a receiving block 30 formed within cover
plate 18. Receiving block 30 locates outlet tube 26 within interior
volume 14 provides structural support to outlet tube 26 and limits
movement of desiccant bags 24 toward upper end 20 of body 12. Outlet
tube 26 also includes a retaining shoulder 32 that serves to limit
movement of desiccant bags 24 toward lower end 16 of body 12. Retaining
shoulder 32 is preferably, but need not be, an integral part of
outlet tube 26. For example, retaining shoulder 32 may alternatively
be a snap ring, a weld bead, or the like.
Referring now to FIGS. 2-3 one of desiccant bags 24 is illustrated
in detail. Desiccant bag 24 includes a filter lid 34 and a filter
bag 36 that together form a shell 38. Shell 38 is formed from a
porous material capable of suitably filtering impurities from the
refrigerant. In the preferred embodiment, shell 38 is fabricated
from flexible polyester felt, and an electrostitch process is employed
to affix filter lid 34 to filter bag 36. Of course, desiccant bag
24 may be fabricated from any suitable material and manufactured
using various well known techniques.
Filter lid 34 has a mounting hole 40 formed therein, and filter
bag 36 is coupled to filter lid 34 around the outer periphery of
filter lid 34 and around mounting hole 40. Thus, desiccant bag 24
is approximately donut-shaped. Filter lid 34 has an exposed upper
surface 41 that performs initial filtration of the refrigerant as
it flows into desiccant bag 24. A quantity of desiccant material
42 is located and maintained within shell 38. Those skilled in the
art will appreciate that the specific composition of desiccant material
42 may vary depending upon the type of refrigerant used in the air
conditioning system. In the preferred embodiment, desiccant material
42 is granular and the bulk of desiccant bag 24 is pliable and deformable.
In the embodiment shown in FIG. 1 each of desiccant bags 24 includes
a substantially rigid eyelet 44 coupled to filter lid 34 and located
around mounting hole 40. Eyelet 44 is configured and sized to receive
outlet tube 26. Eyelet 44 provides structural rigidity to the area
of shell 38 immediately surrounding mounting hole 40. In other words,
eyelet 44 is more rigid than adjacent portions of shell 38. Eyelet
44 is preferably fabricated from aluminum, brass, or stainless steel.
As discussed above, filter lid 34 is coupled to filter bag 36 around
mounting hole 40. As a result of the preferred electrostitching
process, an inner seam 46 (see FIG. 3) is formed around mounting
hole 40. Eyelet 44 preferably includes a first portion 44a that
resides above inner seam 46 and a second portion 44b that resides
below inner seam 46. Consequently, eyelet 44 substantially covers
inner seam 46 and reinforces shell 38 near inner seam 46. Eyelet
44 may alternatively be configured as a one-sided element attached
to either side of inner seam 46 as necessary for the specific application.
Eyelet 44 is suitably sized such that retaining shoulder 32 supports
eyelet 44 and desiccant bag 24 during use. As shown in FIG. 1 retaining
shoulder 32 supports a first desiccant bag 24a via second portion
44b of eyelet 44. The outer diameter of eyelet 44 is sized to provide
a stable support base for the remainder of first desiccant bag 24a.
Thus, retaining shoulder 32 can adequately support first desiccant
bag 24a without tearing shell 38.
A second desiccant bag 24b is preferably maintained on outlet tube
26 above first desiccant bag 24a. In the embodiment illustrated
in FIG. 1 second desiccant bag 24b is similar to first desiccant
bag 24a. Retaining shoulder 32 is positioned on outlet tube 26 such
that first desiccant bag 24a supports second desiccant bag 24b proximate
upper end 20 of body 12.
As shown in FIG. 1 first portion 44a of eyelet 44 associated with
second desiccant bag 24b abuts a lower surface 48 of receiving block
30 when receiver-dryer assembly 10 is in use. As discussed above,
receiving block 30 limits movement of second desiccant bag 24b toward
upper end 20 of body 12. With respect to second desiccant bag 24b,
the outer diameter of first portion 44a of eyelet 44 is approximately
equal to, or greater than, the outer diameter of receiving block
30. When the two diameters are approximately equal, eyelet 44 provides
a sufficient amount of support between second desiccant bag 24b
and receiving block 30 without overly restricting the surface area
of filter lid 34 exposed to the flow of refrigerant.
To assemble receiver-dryer assembly 10 desiccant bags 24 are initially
placed onto outlet tube 26. Outlet tube 26 is then coupled to receiving
block 30 and desiccant bags 24 become sandwiched between retaining
shoulder 32 and receiving block 30. Eventually, cover plate 18 is
secured to body 12 (as shown in FIG. 1) to locate outlet tube 26
and desiccant bags 24 within body 12. It should be appreciated that
receiver-dryer assembly 10 need not employ mounting plates or baffles
to support desiccant bags 24 within body 12.
Referring to FIG. 4 a cross sectional view of a receiver-dryer
assembly 48 according to a second preferred embodiment of the present
invention is illustrated. Receiver-dryer assembly 48 is substantially
similar to receiver-dryer assembly 10 described above. However,
receiver-dryer assembly 48 employs at least one conventional desiccant
bag 50 (i.e., a bag without eyelet 44). Receiver-dryer assembly
48 utilizes support washers 52 rather than desiccant bags 24 to
provide support for desiccant bags 50.
Receiver-dryer assembly 48 includes a first support washer 52a
located between retaining shoulder 32 and shell 38 of a first desiccant
bag 50a. First support washer 52a is configured to support first
desiccant bag 50a above lower end 16 of body 12. First support washer
52a allows first desiccant bag 50a to be mounted within body 12
without using a retaining plate and without having to modify first
desiccant bag 50a with eyelet 44 (see FIGS. 2-3). When in use, first
desiccant bag 50a extends below filter lid 34 and filter bag 36
surrounds first support washer 52a.
A second desiccant bag 50b may also be employed by receiver-dryer
assembly 48. A second support washer 52b is preferably located between
receiving block 30 and second desiccant bag 50b. Second support
washer 52b is positioned on outlet tube 26 such that first desiccant
bag 50a supports second desiccant bag 50b. The outer diameter of
second support washer 52b is approximately equal to, or greater
than, the outer diameter of receiving block 30. When installed properly,
second support washer 52b abuts receiving block 30 which limits
movement of second desiccant bag 50b toward upper end 20 of body
12. Second support washer 52b prevents inner seam 46 (see FIGS.
2-3) of second desiccant bag 50b from directly contacting receiving
block 30. As such, support washer 52b can prevent inner seam 46
from prematurely tearing during use.
In summary, the present invention provides an improved receiver-dryer
for use in an air conditioning system and an improved desiccant
bag for use in the receiver-dryer. The desiccant bag can be mounted
within a receiver-dryer body without the use of mounting plates,
therefore a receiver-dryer in accordance with the present invention
is easy to manufacture and assemble. In addition, the desiccant
bag demonstrates improved structural rigidity over conventional
desiccant bags.
The above description is of a preferred embodiment of the present
invention, and the invention is not limited to the specific embodiment
described and illustrated. For example, a receiver-dryer assembly
need not exclusively utilize any specific type of desiccant bag,
e.g., a receiver-dryer assembly may utilize one desiccant bag having
an eyelet and one conventional desiccant bag in conjunction with
a support washer. In addition, a receiver-dryer assembly may include
any number of desiccant bags as needed for the specific application.
Furthermore, many variations and modifications will be evident to
those skilled in this art, and such variations and modifications
are intended to be included within the spirit and scope of the invention,
as expressed in the following claims. |