Abstrict A container for particulate desiccant comprises a cup and a cap.
The cup includes spaced inner and outer wall portions connected
by a transverse web portion to define a chamber having an opening.
The cap is designed for receipt in the chamber to cover the opening.
In addition, the cap has a hole for receiving the inner wall portion
of the cup. According to one embodiment, the inner wall portion
includes an integral detent formed therein and positioned to detain
the cap in place. The cap has a peripheral surface adapted to rest
on a shoulder formed along the inner surface of the outer wall portion
of the cup to detain the cap in place. The outer wall of the cup
has a resilient flange member that protrudes outwardly from the
cup. This flange is adapted to provide snug, friction fit of the
cup within a fluid flow housing such as an air conditioner accumulator
or the like.
Claims What is claimed is:
1. A method for making a desiccant container comprising the steps
of:
casting a one-piece cup member including spaced inner and outer
wall portions connected by a transverse web portion, providing a
detent member on said inner wall;
inserting desiccant particles between the inner and outer wall
portions;
providing a cap member having a hole therein; and
sliding said hole in said cap over the inner wall portion and into
engagement with said detent to detain the cap in said cup.
2. A desiccant container produced by the process recited in claim
1.
3. A container for a particulate desiccant, said container comprising:
a cup member including spaced inner and outer wall portions connected
by a transverse web portion to define a chamber having an opening;
and
a cap for receipt in said chamber, said cap having a hole for receiving
said inner wall portion when said cap is received in said chamber;
said inner wall portion including a detent protruding from said
inner wall to detain said cap in said chamber.
4. The container as recited in claim 1 wherein said outer wall
portion includes a flared lip extending outwardly from said outer
wall.
5. The container as recited in claim 1 wherein said inner wall
portion defines a sleeve open at either end on different sides of
said container.
6. The container as recited in claim 1 wherein said detent is a
raised bead on said inner wall portion.
7. The container as recited in claim 1 wherein said transverse
web portion and said cap include perforations therein.
8. The container as recited in claim 1 wherein said inner and outer
walls are concentric cylinders.
9. A container as recited in claim 1 wherein said cap has a peripheral
surface adapted for frictional engagement with an inner surface
of said outer wall portion to detain said cap in said chamber.
10. A container as recited in claim 1 wherein said cup is a one-piece
casting.
11. A desiccant container adapted for receipt inside an inner peripheral
wall of a fluid flow housing, said container comprising:
a cup including spaced inner and outer walls connected by a transverse
web portion to define a chamber having an opening; and
a cap for receipt in said chamber, said cap having a hole for receiving
said inner wall portion when said cap is received in said chamber;
said outer wall having a peripheral lip extending outwardly therefrom
adapted for frictional engagement with said inner peripheral wall
of said housing.
12. The container as recited in claim 11 wherein said transverse
web portion and said cap include perforations therein.
13. The container as recited in claim 11 wherein said inner and
outer walls are concentric cylinders.
14. The container as recited in claim 11 wherein said inner wall
portion defines a passage open at either end on different sides
of said container.
15. The container as recited in claim 11 including first and second
plies of permeable lining material for placement in said chamber
to trap the particulate desiccant in said container.
16. A container as recited in claim 11 wherein said cartridge is
a one-piece casting.
17. A container for a particulate desiccant, said container comprising:
a cup member including spaced inner and outer wall portions connected
by a transverse web portion to define a chamber having an opening;
and
a cap for receipt in said chamber, said cap having a hole for receiving
said inner wall portion when said cap is received in said chamber;
said inner wall portion including a detent positioned to detain
said cap in said chamber, said detent comprising a raised bead on
said inner wall portion.
18. A container for a particulate desiccant, said container comprising:
a cup member including spaced inner and outer wall portions connected
by a transverse web portion to define a chamber having an opening;
and
a cap for receipt in said chamber, said cap having a hole for receiving
said inner wall portion when said cap is received in said chamber;
said inner wall portion including a detent positioned to detain
said cap in said chamber, said detent comprising a resilient flange
on said inner wall portion.
19. A method for making a desiccant container for use within a
fluid flow housing, said method comprising the steps of:
casting a one-piece cup member including spaced inner and outer
wall portions connected by a transverse web portion, providing an
outwardly extending lip member from said outer wall;
inserting desiccant particles between the inner and outer wall
portions;
providing a cap member having a hole therein; and
sliding said cap over said inner wall and detaining said cap in
said cup.
Description BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to air or fluid dryers, and more particularly,
it relates to desiccant containers for use as proximity dryers or
as flow-through filter-dryers for liquid refrigerant in-line installations
in automotive air conditioning systems and the like.
2. Background of the Invention
Desiccants are commonly used in automotive air conditioning systems
for dehydrating air and refrigerants. Particulate desiccants are
common in such systems because the high surface area-to-volume ratios
of the particles facilitates the interaction of the particles with
surrounding air or fluid. Since the particles of desiccant must
be held in the air or fluid stream and prevented from contaminating
other parts of the system, the particles must be held in a container
which is permeable to the air or fluid but impermeable to the particles.
One form of dryer used in automotive air conditioning systems includes
an elongated receiver or accumulator canister having inlet and outlet
ports communicating with the interior of the canister. A desiccant
container is positioned in the interior of the canister and allows
for air and/or fluid through the desiccant material.
One form of package-type desiccant container for use in an accumulator
or receiver dryer is constructed from synthetic felted wool or polyester
which is filled with desiccant and then sealed by stitching or fusing.
One drawback to this form of package is that the felted bag may
not conform to the shape of the canister, so that air or fluid may
bypass the desiccant. Another drawback is that the bag may be non-uniform
in shape, thereby making automatic assembly of the dryer difficult.
If felted polyester is used as a less expensive substitute for
felted wool, the seams of the bag may be formed by ultrasonic welding.
Unfortunately, the reliability of such ultrasonic welds is questionable
and the bag may open up, allowing adsorbent material to escape from
the bag and potentially contaminate the system. In addition, the
felted polyester bag is vulnerable to burn-through when the dryer
is welded shut.
In another proposed form of an accumulator or receiver dryer, particulate
desiccant is trapped between a pair of grids or plates which are
welded or press fit inside the canister. According to one embodiment,
the desiccant is charged by pouring the desiccant particles into
the canister once a first of the grids or plates is positioned.
A pipe extends through holes in the grids or plates to exhaust dried
air to an outlet port. A dryer of this form is likely to be difficult
to assemble because the grids or plates must be slid into position
and, in some cases, welded inside the canister.
Furthermore, in those embodiments in which the desiccant particles
are manually poured into the canister, the desiccant must be pre-measured
due to the difficulty of controlling the amount of desiccant poured
into the canister based on visual observation alone. The pouring
of the desiccant creates a risk of accidental contamination outside
the accumulator since desiccant particles may fall into the pipe
communicating with the outlet port.
SUMMARY OF THE INVENTION
These drawbacks and others are overcome by means of the present
invention embodied in a container for a particulate desiccant which
comprises a generally cylindrical cup and a cap. The cup includes
spaced inner and outer wall portions connected by a transverse web
portion to define a chamber having an opening. The cap is designed
for receipt in the chamber to hold the desired particulate desiccant
material in place in the cup. In addition, the cap has a hole for
receiving the inner wall portion of the cup when the cap is received
in the chamber.
According to one embodiment, the inner wall portion includes an
integral detent extending into the chamber and positioned to detain
the cap in place. Two examples of such integral detents are a raised
bead and a resilient flange. According to another embodiment, the
outer wall of the container has an outwardly extending lip defining
a peripheral surface for frictional engagement with an inner surface
of the canister or housing of the air conditioning unit.
Both the transverse web portion and the cap are perforated to allow
air or fluid to reach the desiccant housed thereon. The container
includes first and second plies of permeable lining material which
trap the particulate desiccant in the .container. In addition, the
inner wall portion defines a sleeve open at either end on different
sides of said container. This sleeve fits over a pipe communicating
with one of the ports in the air conditioning system so that air
or fluid passing through the desiccant may exit the system.
According to another aspect, the present invention is embodied
in a desiccant container produced by casting a one-piece cup member
including spaced inner and outer wall portions connected by a transverse
web portion; inserting permeable lining material and desiccant beads
or the like between the inner and outer wall portions such that
the desiccant beads are trapped between plies of the permeable lining
material; and sliding a central hole of a cap over the inner wall
portion and into engagement with a detent to detain the cap and
the particulate desiccant in the chamber.
In accordance with the invention, the desiccant material is placed
into the container prior to insertion of the container into the
canister. Accordingly, the amount of desiccant charged into the
container is relatively easy to control and the risk that desiccant
will enter a pipe communicating with one of the ports of the air
conditioning system is minimized. Rigidity and uniformity of the
container enable it to be automatically installed, if desired.,
into the dryer canister, while the container protects the permeable
lining material from burn-through when the air conditioning or refrigeration
system canister is welded.
The desiccant container may be fabricated from reusable or recyclable
materials. Removable detention of the cap in the cartridge permits
the desiccant container to be recharged with fresh desiccant without
damaging the container.
Additionally, since the cup-shaped container is formed into a specific,
definite shape and dimension depending on the particular canister
in which it is to be housed, the air or refrigerant system is efficient,
minimizing by-pass of the fluid flow from the desiccant particles
which can in some cases occur.
Therefore, it is one object of the invention to provide a desiccant
package which is simple to assemble, shaped to fit the dryer canister
and capable of automatic installation. This and other objects, features
and advantages of the present invention will be described in further
detail in connection with preferred embodiments of the invention
shown in the accompanying drawings, wherein:
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a front elevational view of a first embodiment of a desiccant
container;
FIG. 2 is a top plan view of the desiccant container of FIG. 1;
FIG. 3 is a cross-sectional view of the desiccant container taken
along the line 3--3 in FIG. 2;
FIG. 4 is a bottom plan view of the desiccant container of FIG.
1;
FIG. 5 is a front elevational view of a second embodiment of the
invention;
FIG. 6 is a cross-sectional view of the desiccant container of
FIG. 5 installed in a canister of an accumulator or receiver dryer;
FIG. 7 is a top plan view of the desiccant container shown in FIG.
5; and
FIG. 8 is a cross-sectional view of the canister shown in FIG.
7 taken along the line 8--8 of FIG. 7.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As best shown in FIGS. 1-4 a first embodiment of a desiccant container
10 for holding particulate desiccant 12 comprises a generally cylindrically
cross-sectioned cup 14 and a cap 16. The cup 14 is a one-piece plastic
molding which includes a cylindrical inner wall portion 18 a cylindrical
outer wall portion 20 concentric with the inner wall portion 18
and a bottom defined by transverse web portion 22. The inner and
outer wall portions 18 20 and the transverse web portion 22 define
a chamber 24 having an opening 26.
The outer wall 20 is sized to fit snugly into the inside diameter
of dryer canister to prevent air or fluid from bypassing the container
10. The cylindrical inner wall portion 18 defines a passage 30 which
opens on a web side 32 and a cap side 34 of the container 10 so
that the inner wall portion 18 may serve as a sleeve for receiving
a pipe or conduit communicating with an outlet or inlet port of
the dryer or refrigerant system.
As best shown in FIG. 3 the cap 16 is generally disc-shaped and
has a central hole 38 for receiving the inner wall portion 18 of
the cup 14. The cap 16 also includes a peripheral portion 40 and
an inner mounting surface 42; each extending downwardly from the
top of flat annular portion 44. The peripheral portion 40 is dimensioned
for snug reception within inner shoulder 48 of the outer wall portion
20 to retain the cap 16 in the chamber 24 of the cup 14. Inner mounting
surface 42 surrounds the hole 38. As shown, shoulder 48 extends
along the circumference of the inside surface of outer wall 20.
Flat annular portion 44 of the cap 16 and the transverse web portion
22 of the cup 14 are each perforated with a number of symmetrically
arrayed ports or perforations (one each shown at 50 and 52 FIG.
2 and 4) so that the flat annular portion 44 and the transverse
web portion 22 are each permeable to the air or fluid to be dried.
In the example shown, the ports 50 52 are arranged in concentric
annular rows such that the two inner rows have nine ports each and
the outer row has eighteen ports. The precise arrangement of the
ports is not critical to the operation of the desiccant container
10 as long as the desiccant 12 remains contained and air or fluid
(not shown) is allowed to enter the container 10 interact evenly
with the desiccant 12 and exhaust from the container 10.
The inner wall portion 18 includes an integral detent 54 formed
on an outer surface 56 of the inner wall portion 18 in the form
of a resilient flange tapered radially outwardly toward the interior
of the chamber 24. The detent 54 presses against either the flat
annular portion 44 of the cap 16 to detain the cap in the chamber
24. Since the detent 54 is resilient, the cap 16 may be detached
from the detent 54 and removed from the chamber 24 to reach the
desiccant 12.
Plies 58 60 of a permeable lining material such as felted polyester
or gauze are placed inside the chamber 24 near the transverse web
portion 22 and the cap 16 to trap the desiccant in the container
10. The lining material must be permeable to the air or fluid (not
shown) to be dried but impermeable to the particulate desiccant
12. If gauze is used, the mesh size of the gauze must be significantly
smaller than the grain size of the desiccant. While the plies 58
60 are shown in FIG. 3 as circular liners or pads having central
holes 62 64 embracing and surrounding the inner wall portion 18
the plies may also be separate plies of a permeable capsule or pouch
(not shown), such as a torroidal capsule shaped to surround the
inner wall portion 18.
A second embodiment of a desiccant container 10 is shown in FIGS.
5-8. In particular, the desiccant container 10 for holding particulate
desiccant 12 comprises a generally cylindrically cross-sectioned
cup 14 and a cap 16. The cup 14 is a one-piece plastic molding which
includes a cylindrical inner wall portion 18 a cylindrical outer
wall portion 20 concentric with the inner wall portion 18 and a
bottom defined by transverse web portion 22. The inner and outer
wall portions 18 20 and the transverse web portion 22 define a
chamber 24 having an opening 26. The transverse web portion 22 is
perforated (not shown) to conduct air or fluid (not shown) into
or out of the chamber 24.
As best shown FIGS. 7 and 8 the cap 16 is generally disc-shaped
and has a central hole 38 for receiving the inner wall portion 18
of the cartridge 14. The cap 16 optionally also includes a peripheral
portion 40 which extends along the perimeter of the cap 16 and an
inner mounting surface 42 which surrounds the hole 38. The flat
annular portion 44 is perforated as at 50 to conduct air or fluid
(not shown) into or out of the chamber 24.
The inner wall portion 18 includes an integral detent 54 formed
on outer surface 56 of the inner wall portion 18. Here, the detent
54 is shaped as a bead rather than a resilient flange, however.
The detent 54 in the form of a bead may extend continuously around
a cross-section of the outer surface 56 as shown in FIGS. 7 and
8 or may consist of one or more beads discontinuously distributed
on a cross-section of the outer surface 56. Preferably, the inner
wall portion 18 and the detent 54 have sufficient resilience that
the cap 16 may be detached from the inner wall portion 18 and removed
from the chamber 24 to reach the desiccant 12.
The outer wall portion 20 includes an outwardly flared lip 66.
The flared lip 66 terminates in a shoulder 68 which engages peripheral
portion 40 of the cap. Flared lip 66 is adapted to resiliently fit
within the lid of canister 28. This lip facilitates snug fit of
the cup within the canister of the appropriate air conditioning
or refrigeration system. The lip further serves as a seal to prevent
air or fluid escape that may otherwise occur along the interface
between the circumference of the cup and the lid of the canister.
Turning now to FIG. 6 it can be seen that lip 66 resiliently bears
upon inside diameter of dryer canister 28 to provide a snug fit
of the container 10 in the canister 28. The lip 66 also serves to
prevent air or fluid from bypassing the container so as to ensure
passage thereof over the desiccant particles or beads. Cylindrical
inner wall portion 18 defines passage 30 which serves as a sleeve
for receiving conduit 36 communicating with an inlet portion or
outlet portion of the dryer or refrigerant system.
One method for fabricating the desiccant container 10 includes
the step of casting or injection molding the cup 14 to form a one-piece
plastic member having the inner and outer wall portions 18 20 connected
by the transverse web portion 22. One plastic suited for use in
casting the cup 14 is polypropylene. Polyethylene may also be used
but is not preferred. The cap 16 is likewise cast from plastic.
The permeable lining material 58 60 and the desiccant 12 are inserted
into the chamber 24 between the inner and outer wall portions 18
20 such that the desiccant particles 12 are trapped between the
plies 58 60 of the permeable lining material. Then, the hole 38
in the cap 16 is slid over the inner wall portion 18 and into engagement
with the detent 54 to detain the cap 16 and the particulate desiccant
12 in the chamber 24.
Preferably, permeable lining material and desiccant are inserted
by sliding a first ply 58 of the plies 58 60 down the inner wall
portion 18 and placed adjacent to the transverse web portion 22.
The desiccant is then charged into the chamber 24 as by pouring.
Since the chamber 24 is torroidal and relatively shallow, the height
of the desiccant 12 in the chamber 24 can be seen through the opening
26 so that the proper amount of desiccant is charged in a manual
operation. Once the desiccant is charged, a second ply 60 of the
plies 58 60 is slid down the inner wall portion 18 against the
desiccant 12.
The cup 14 may be vibrator or bowl fed to a robotic arm for automatic
installation into a dryer canister 28 (partially shown in section
in FIG. 6). Furthermore, the plies 58 60 of lining material are
relatively resistant to burn-through in the cup 14 while the dryer
canister 28 is being welded (not shown). As stated previously, the
cup 14 may be sized to fit snugly in the canister 28 to inhibit
bypass flow of air or fluid (not shown) to be dried. The detents
and friction fits used to detain the cap 16 on the cup 14 are highly
reliable so that the risk that desiccant will escape and contaminate
other parts of the air conditioning or refrigeration system (not
shown)is minimized.
Various changes or modifications in the invention described may
occur to those skilled in the art without departing from the true
spirit or scope of the invention. The above description of preferred.
embodiments of the invention is intended to be illustrative and
not limiting, and it is not intended that the invention be restricted
thereto but that it be limited only by the true spirit and scope
of the appended claims. |