Abstrict A desiccant canister assembly for use in an air dryer system includes
a pair of concentrically disposed casings, top and bottom end caps,
top and bottom porous plates and moisture absorbing material. A
cylindrical opening is defined in between the casings. The top end
cap affixes to the upper ends of the casings. The bottom end cap
affixes to the lower ends of the casings. Each end cap features
openings that allow air to flow through the cylindrical opening.
The bottom porous plate is situated at a bottom of the cylindrical
opening against the bottom cap. The top porous plate is slidably
disposed within the cylindrical opening near the upper ends of the
casings. The absorbing material is disposed within the cylindrical
opening between the porous plates. The desiccant assembly also includes
a mechanism for compacting the absorbing material between the porous
plates. The desiccant assembly further includes a mechanism for
aligning and securably retaining the desiccant canister assembly
within a canister housing of the air dryer system. The latter mechanism
includes a positioning bore defined within an inner one of the casings
and through a center of each end cap. The positioning bore receives
a threaded rod extending from a center of an upper base of the housing
about which the desiccant assembly securably retains through a lock
washer and a stop nut so that an outer ring portion of the top cap
aligns with and seals via an o-ring against a sealing flange of
the housing.
Claims I claim:
1. A desiccant canister assembly for use in a gas dryer system,
said desiccant canister assembly comprising:
(a) a pair of concentrically disposed casings, each having an upper
end and a lower end, such that a cylindrical opening is defined
between said casings;
(b) a pair of end caps a bottom of which affixed to said lower
ends of said pair of casings and a top of which affixed to said
upper ends of said pair of casings, each of said end caps defining
openings therein for allowing flow of gas through said cylindrical
opening;
(c) a bottom porous plate situated approximate a bottom of said
cylindrical opening against said bottom end cap;
(d) a top porous plate slidably disposed within said cylindrical
opening near said upper ends of said casings;
(e) a moisture absorbing material disposed within said cylindrical
opening between said top and said bottom porous plates;
(f) a retaining ring affixed within said cylindrical opening to
one of said casings approximate said upper end thereof;
(g) a spring compressively situated between said retaining ring
and said top porous plate so as to maintain a compressive force
upon said moisture absorbing material disposed between said top
and said bottom porous plates; and
(h) a means for aligning and securably retaining said desiccant
canister assembly within a desiccant canister assembly housing of
said gas dryer system.
2. The desiccant canister assembly as recited in claim 1 wherein
said means for aligning and securably retaining includes a positioning
bore defined within an inner one of said casings and through a center
of each of said end caps, said positioning bore for receiving a
threaded rod extending from a center of an upper base of said housing
about which said desiccant canister assembly aligns and securably
retains via a lock washer and a stop nut.
3. The desiccant canister assembly as recited in claim 1 further
comprising an o-ring retained within a groove defined within an
outer ring portion of said top end cap for sealing said desiccant
canister assembly against a sealing flange of said housing.
4. The desiccant canister assembly as recited in claim 3 wherein
said means for aligning and securably retaining includes a positioning
bore defined within an inner one of said casings and through a center
of each of said end caps, said positioning bore for receiving a
threaded rod extending from a center of an upper base of said housing
about which said desiccant canister assembly retains via a lock
washer and a stop nut so that said outer ring portion of said top
end cap aligns with and seals via said o-ring against said sealing
flange of said housing.
5. The desiccant canister assembly as recited in claim 1 wherein
said retaining ring affixes within a groove defined within an outer
one of said casings approximate said upper end thereof.
6. The desiccant canister assembly as recited in claim 1 wherein
said top and said bottom porous plates each have a plurality of
small apertures for allowing flow of gas therethrough.
7. The desiccant canister assembly as recited in claim 1 wherein
said top and bottom end caps are affixed to said upper and said
lower ends of said casings, respectively, via one of a molding operation
and melding operation.
8. A desiccant canister assembly for use in a gas dryer system,
said desiccant canister assembly comprising:
(a) a pair of concentrically disposed casings, each having an upper
end and a lower end, such that a cylindrical opening is defined
between said casings;
(b) a pair of end caps a bottom of which affixed to said lower
ends of said pair of casings and a top of which affixed to said
upper ends of said pair of casings, each of said end caps defining
openings therein for allowing flow of gas through said cylindrical
opening;
(c) a bottom porous plate situated approximate a bottom of said
cylindrical opening against said bottom end cap;
(d) a top porous plate slidably disposed within said cylindrical
opening near said upper ends of said casings;
(e) a moisture absorbing material disposed within said cylindrical
opening between said top and said bottom porous plates;
(f) a means for compacting said moisture absorbing material between
said top and said bottom porous plates; and
(g) a means for aligning and securably retaining said desiccant
canister assembly within a desiccant canister assembly housing of
said gas dryer system.
9. The desiccant canister assembly as recited in claim 8 wherein
said means for aligning and securably retaining includes a positioning
bore defined within an inner one of said casings and through a center
of each of said end caps, said positioning bore for receiving a
threaded rod extending from a center of an upper base of said housing
about which said desiccant canister assembly securably retains via
a lock washer and a stop nut.
10. The desiccant canister assembly as recited in claim 8 further
comprising an o-ring retained within a groove defined within an
outer ring portion of said top end cap for sealing said desiccant
canister assembly against a sealing flange of said housing.
11. The desiccant canister assembly as recited in claim 10 wherein
said means for aligning and securably retaining includes a positioning
bore defined within an inner one of said casings and through a center
of each of said end caps, said positioning bore for receiving a
threaded rod extending from a center of an upper base of said housing
about which said desiccant canister assembly retains via a lock
washer and a stop nut so that said outer ring portion of said top
end cap aligns with and seals via said o-ring against said sealing
flange of said housing.
12. The desiccant canister assembly as recited in claim 8 wherein
said means for compacting said moisture absorbing material includes:
(a) a retaining ring affixed within said cylindrical opening to
an outer one of said casings approximate said upper end thereof;
and
(b) a spring compressively situated between said retaining ring
and said top porous plate so as to maintain a compressive force
upon said moisture absorbing material disposed in said cylindrical
opening between said top and said bottom porous plates.
13. The desiccant canister assembly as recited in claim 12 wherein
said retaining ring affixes within a groove defined within said
outer casing approximate said upper end thereof.
14. The desiccant canister assembly as recited in claim 8 wherein
said means for compacting said moisture absorbing material includes:
(a) a retaining ring affixed within said cylindrical opening to
an outer one of said casings approximate said upper end thereof;
(b) an uppermost porous plate abutting an interior facing side
of said retaining ring within said cylindrical opening; and
(c) a spring compressively situated between said uppermost and
said top porous plates so as to maintain a compressive force upon
said moisture absorbing material disposed in said cylindrical opening
between said top and said bottom porous plates.
15. The desiccant canister assembly as recited in claim 14 wherein
said retaining ring affixes within a groove defined within said
outer casing approximate said upper end thereof.
16. The desiccant canister assembly as recited in claim 14 wherein
said porous plates each have a plurality of small apertures for
allowing flow of gas therethrough.
17. The desiccant canister assembly as recited in claim 8 wherein
said top and bottom end caps are affixed to said upper and said
lower ends of said casings, respectively, via one of a molding operation
and melding operation.
Description CROSS-REFERENCE TO RELATED APPLICATIONS
This application is related to copending applications Ser. No.
08/713782 and 08/710207 entitled, Regenerative Desiccant Air
Dryer, and Molded Rubber Valve Seal For Use In Predetermined Type
Valves Such As A Check Valve In A Regenerative Air Dryer, respectively,
all sharing the same filing date of the present application, Sep.
13 1996. These patent applications are assigned to the assignee
of the present invention, and their teachings are incorporated into
the present document by reference.
FIELD OF THE INVENTION
The present invention generally relates to an air drying element
for use in a compressed air system. More particularly, the present
invention pertains to a desiccant canister assembly which includes
a mechanism for aligning and securably retaining the desiccant canister
assembly within a desiccant canister assembly housing of an air
dryer system.
BACKGROUND OF THE INVENTION
It is well known that air dryer systems are designed to remove
moisture vapor from a stream of compressed air into which the air
dryer system is incorporated. In practice, an air dryer system employs
one or more standard air drying assemblies each of which contains
a moisture absorbing material to absorb the moisture from the air.
In air dryer systems having one air drying assembly, the air drying
assembly through its moisture absorbing material absorbs the moisture
suspended in the compressed air passing through it until the compressor
stops operating after a preset time. By design, this type of air
dryer system then automatically flushes a quantity of the dried
compressed air stored in a purge volume back through the moisture
absorbing material to draw out the absorbed moisture. The stream
of compressed air with the revaporized moisture it carries is then
discharged to the atmosphere thereby regenerating the moisture absorbing
material contained in the air drying assembly.
In air dryer systems having two air drying assemblies, the air
drying system alternately cycles between removing moisture from
air passing through a first drying assembly while purging from a
second drying assembly moisture previously collected therein and
removing moisture from air passing through the second drying assembly
while purging from the first drying assembly moisture previously
collected therein.
Prior to the present invention, such prior art air dryer systems
generally have used the standard air drying assembly to perform
the air drying function. Whether the air dryer system employs one
or more standard air drying assemblies, each standard air drying
assembly inserts into a housing designed to hold same. The prior
art housings, however, generally retain the standard air drying
assembly through a tight press fitting, or in other terms, interference
fitting of the assembly within the housing. Specifically, the fit
of the standard air drying assembly into its corresponding housing
in the air dryer system is so tight that it typically must be hammered
into the housing with a mallet or like instrument.
The standard air drying assembly and corresponding housing design
thus present a number of shortcomings. First, the process of installing
the standard air drying assembly into the housing is quite strenuous
and takes too much time. Second, one cannot be sure whether the
standard air drying assembly is properly aligned within the housing
so that the top of the assembly seats against and makes an air tight
seal with a sealing face of the housing. Third, removal of the standard
air drying assembly from the housing is often quite difficult because
of its tight fit within the housing. For these reasons, a novel
air drying assembly that does not exhibit the disadvantages of the
prior art standard air drying assembly would be very well received
in the field of pneumatics. Accordingly, such a novel air drying
assembly as alluded to above is described and claimed herein as
follows.
It should be noted that the foregoing background information is
provided to assist the reader in understanding the instant invention.
Accordingly, any terms of art used herein are not intended to be
limited to any particular narrow interpretation unless specifically
stated otherwise in this document.
SUMMARY OF THE INVENTION
In a presently preferred embodiment, the present invention provides
a desiccant canister assembly for use in an air dryer system. The
desiccant canister assembly includes a pair of concentrically disposed
casings, top and bottom end caps, top and bottom porous plates and
moisture absorbing material. A cylindrical opening is defined in
between the casings. The top cap affixes to the upper ends of the
casings. The bottom cap affixes to the lower ends of the casings.
Each end cap features openings that allow air to flow through the
cylindrical opening. The bottom porous plate is situated at a bottom
of the cylindrical opening against the bottom cap. The top porous
plate is slidably disposed within the cylindrical opening near the
upper ends of the casings. The moisture absorbing material is disposed
within the cylindrical opening between the top and bottom porous
plates. The desiccant canister assembly also includes a mechanism
for compacting the moisture absorbing material between the porous
plates. The desiccant canister assembly further includes a mechanism
for aligning and securably retaining the desiccant canister assembly
within a canister housing of the air dryer system. The latter mechanism
includes a positioning bore defined within an inner one of the casings
and through a center of each end cap. The positioning bore receives
a threaded rod extending from a center of an upper base of the housing
about which the desiccant assembly securably retains with a securing
device so that an o-ringed outer ring portion of the top cap aligns
with and seals against a sealing flange of the canister housing.
OBJECTS OF THE INVENTION
It is, therefore, one of the primary objects of the present invention
to provide a novel desiccant canister assembly for use in an air
dryer system.
Another object of the present invention is to provide a novel desiccant
canister assembly inclusive of a mechanism for aligning and securably
retaining the desiccant canister assembly within a corresponding
housing of an air dryer system.
Yet another object of the present invention is to provide a novel
desiccant canister assembly that features a positioning bore through
its center through which inserts a threaded rod of a housing for
the canister assembly so as to retain the canister assembly about
the threaded rod with a securing mechanism so that a top of the
canister assembly aligns with and seals against a sealing flange
of the housing.
Still another object of the present invention is to provide a novel
desiccant canister assembly that features a positioning bore through
its center through which inserts a threaded rod of a housing for
the canister assembly so as to retain the canister assembly about
the threaded rod with a lock washer and a stop nut so that an o-ringed
outer ring portion of a top of the canister assembly aligns with
and seals against a sealing flange of the housing.
Even another object of the present invention is to provide a novel
desiccant canister assembly which installs within a corresponding
housing of an air dryer system far easier than prior art desiccant
canisters.
In addition to the objects and advantages of the desiccant canister
assembly set forth above, various other objects and advantages will
become more readily apparent to persons skilled in the air dryer
system art from a reading of the detailed description section of
this document. Such other objects and advantages will become particularly
apparent when the detailed description is considered in conjunction
with the attached drawings and with the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view of a desiccant canister assembly
according to the present invention.
FIG. 2 is another cross-sectional view of a desiccant canister
assembly according to the present invention.
FIG. 2a is a top plan view of a top end cap of the desiccant canister
assembly shown in FIGS. 1 and 2 illustrating an outer ring portion
of the top end cap.
FIG. 2b is a bottom plan view of a bottom end cap of the desiccant
canister assembly shown in FIGS. 1 and 2.
FIG. 2c is an enlarged partial cross-sectional view of an o-ring
groove within the outer ring portion shown in FIG. 2a.
FIG. 2d is an enlarged partial cross-sectional view of a retaining
ring groove within an outer casing of the desiccant canister assembly
shown in FIGS. 1 and 2.
FIG. 3 is a cross-sectional view of a desiccant canister assembly
according to the present invention contained within a corresponding
canister housing of an air dryer system.
FIG. 4 is a perspective view of a regenerative air dryer system
featuring two canister housings of the type shown in FIG. 3.
DETAILED DESCRIPTION OF THE INVENTION
Before describing the present invention in detail, for the sake
of clarity and understanding, the reader is advised that identical
components having identical functions in each of the accompanying
drawings have been marked with the same reference numerals throughout
each of the several Figures illustrated herein.
FIGS. 1 through 3 illustrate the essential details of a desiccant
canister assembly for use in an air dryer system. The desiccant
canister assembly may be used within a variety of air dryer systems
bearing at least one canister housing having the basic structural
characteristics shown in FIG. 3. FIG. 4 shows a regenerative air
dryer system bearing two canister housings each having the basic
structural characteristics shown in FIG. 3. It is within a canister
housing having these basic structural characteristics that the desiccant
canister assembly of the present invention is primarily designed
to be retained. One such canister housing is featured in one of
the aforementioned documents previously incorporated herein by reference.
In a presently preferred embodiment, the desiccant canister assembly,
generally designated 100 includes a pair of concentrically disposed
casings 101 and 102 top and bottom end caps 103 and 104 top and
bottom porous plates 105 and 106 and moisture absorbing material
107. The casings 101 and 102 each have an upper end and a lower
end and are disposed to form a cylindrical opening 108 between them.
Bottom end cap 104 affixes to the lower ends of casings 101 and
102. Likewise, top end cap 103 affixes to the upper ends of the
casings. Preferably, top and bottom end caps 103 and 104 are affixed
to the upper and lower ends of the casings, respectively, via a
molding or melding operation. As shown in FIGS. 2a and 2b, the top
and bottom end caps each have openings 00 which allow air to flow
through the cylindrical opening 108. Top end cap 103 also features
an outer ring portion 110. The outer ring portion 110 preferably
includes a groove 111 within which an o-ring 112 retains as shown
in FIG. 2c. Through o-ring 112 the outer ring portion 110 of top
end cap 103 is seatable against, and capable of making an air tight
seal with, a sealing flange 201 of a canister housing, generally
designated 200 as shown in FIG. 3. Sealing flange 201 is found
on an upper base, generally designated 202 of canister housing
200.
Referring again to FIGS. 1 and 3 bottom porous plate 106 is situated
approximate a bottom of the cylindrical opening 108 against bottom
end cap 104. Top porous plate 103 is slidably disposed within the
cylindrical opening 108 near the upper ends of casings 101 and 102.
The moisture absorbing material 107 is disposed within cylindrical
opening 108 between top and bottom porous plates 105 and 106. The
moisture absorbing material 107 may be selected from any one of
several commercially available types such as a mesh white activated
alumina desiccant. Preferably in pelletized form, the desiccant
may consist of approximately three sixteenths of an inch (3/16")
sized beads or spheres of the activated alumina desiccant.
The desiccant canister assembly 100 also includes a means, generally
designated 130 for compacting the moisture absorbing material 107
between top and bottom porous plates 105 and 106. The compacting
means 130 includes a retaining ring 131 and a spring 135. Retaining
ring 131 affixes within cylindrical opening 108 to an outer one
101 of the casings approximate its upper end as is best shown in
FIGS. 1 and 2d. Preferably, retaining ring 131 fixes within a groove
132 defined within outer casing 101 approximate the upper end of
outer casing 101. Spring 135 is compressively situated between retaining
ring 131 and top porous plate 105 so as to maintain a compressive
force upon the moisture absorbing material 107 disposed in the cylindrical
opening 108 between top and bottom porous plates 105 and 106. The
compacting means 130 may also feature an uppermost porous plate
136 abutting an interior facing side of retaining ring 131 within
cylindrical opening 108 so that uppermost plate 136 is sandwiched
between retaining ring 131 and spring 135. Though situated between
uppermost plate 136 and top plate 105 spring 135 still compresses
the moisture absorbing material 107 between top and bottom porous
plates 105 and 106. For desiccant canister assemblies so equipped,
the uppermost porous plate 136 provides yet another barrier to prevent
crumbled desiccant particulates from escaping into the air dryer
system. Each of the porous plates 105 106 and 136 have a plurality
of apertures that allow flow of air while trapping such particulates.
The dimensions of each of the apertures, of course, should be smaller
than the desiccant pellets that may be used as the moisture absorbing
material 107.
The desiccant canister assembly 100 also includes a means, generally
designated 140 for aligning and securably retaining the desiccant
canister assembly 100 within canister housing 200 of FIG. 3. As
shown in FIGS. 1 through 3 the means for aligning and securably
retaining 140 includes a positioning bore 141 defined within an
inner one 102 of the casings and through a center of each of the
end caps 103 and 104. The positioning bore 141 receives a threaded
rod 203 as shown in FIG. 3. The threaded rod 203 extends from a
center of an upper base 202 of canister housing 200. The desiccant
canister assembly 100 securably retains about threaded rod 203 via
a securing means 204 such as a lock washer 205 and a stop nut 206.
It is through this means for aligning and securably retaining 140
that outer ring portion 110 of top end cap 103 aligns with and seals
via said o-ring 112 against sealing flange 201 of canister housing
200.
While the presently preferred embodiment for carrying out the desiccant
canister assembly invention has been set forth in detail according
to the Patent Act, those persons of ordinary skill in the technical
art to which this invention pertains will recognize various alternative
ways of practicing the invention without departing from the spirit
and scope of the appended claims. Those of ordinary skill will also
recognize that the foregoing description is merely illustrative
and is not intended to limit any of the following claims to any
particular narrow interpretation.
Accordingly, to promote the progress of science and useful arts,
I secure for myself by Letters Patent exclusive rights to all subject
matter embraced by the following claims for the time prescribed
by the Patent Act. |