Abstrict A microwave-regenerable desiccant cartridge including a casing
of transparent plastic, indicating desiccant within the casing,
a bottom wall and a top wall in the casing, apertures in the bottom
and top walls of the casing of a smaller size than the desiccant
within the casing, and outwardly extending legs on both the top
wall and the bottom wall to space the apertures in the bottom and
top walls from a supporting surface of a microwave oven on which
they are placed in facing relationship.
Claims What is claimed is:
1. A microwave regenerable and reusable desiccant cartridge comprising
a casing fabricated of plastic which transmits microwave energy
without itself being deleteriously affected, apertures in said casing
for permitting communication between the inside of said casing and
the environment in which said casing is located, desiccant material
within said casing for adsorbing moisture which passes through said
apertures from the environment and for being regenerated by microwave
energy which drives moisture from said desiccant material through
said apertures, said casing having two opposing walls which are
larger than the side walls thereof, and said apertures being located
in said opposing walls.
2. A microwave regenerable and reusable desiccant cartridge as
set forth in claim 1 wherein said casing is fabricated from transparent
plastic which permits viewing of said desiccant from outside of
said casing.
3. A microwave regenerable and reusable desiccant cartridge as
set forth in claim 2 wherein said plastic is a polycarbonate.
4. A microwave regenerable and reusable desiccant cartridge as
set forth in claim 2 wherein said desiccant is of the indicating
type which has different colors when dry and when it has absorbed
moisture.
5. A microwave regenerable and reusable desiccant cartridge comprising
a casing fabricated of plastic which transmits microwave energy
without itself being deleteriously affected, apertures in said casing
for permitting communication between the inside of said casing and
the environment in which said casing is located, desiccant material
within said casing for adsorbing moisture which passes through said
apertures from the environment and for being regenerated by microwave
energy which drive moisture from said desiccant material through
said apertures, said cartridge comprising a first section with a
first wall and a first peripheral flange depending therefrom, a
second section with a second wall and a second peripheral flange
depending therefrom, said first flange being of slightly larger
perimeter than said second flange to receive said second flange
with a sliding fit, and detent means for holding said first and
second peripheral flanges in assembled relationship with said first
and second walls located in facing relationship.
6. A microwave regenerable and reusable desiccant cartridge as
set forth in claim 5 wherein said apertures are located in said
walls.
7. A microwave regenerable and reusable desiccant cartridge as
set forth in claim 6 wherein said casing is fabricated from transparent
plastic which permits viewing of said desiccant from outside of
said casing.
8. A microwave regenerable and reusable desiccant cartridge as
set forth in claim 7 wherein said desiccant is of the indicating
type which has different colors when dry and when it has absorbed
moisture.
9. A microwave regenerable and reusable desiccant cartridge comprising
a casing which transmits microwave energy without being deleteriously
affected, top and bottom walls in said casing, desiccant material
within said casing, and a plurality of apertures in said top and
bottom walls for permitting communication between the inside of
said casing and the environment in which said casing is located
so as to permit moisture to pass therethrough into the inside of
said casing for adsorption by said desiccant and to permit said
moisture to be driven out through said apertures during microwave
regeneration of said desiccant, and means on both said top wall
and said bottom wall for spacing said apertures therein from a supporting
surface in a microwave oven when said casing is laid on said supporting
surface with either said top wall or said bottom wall facing said
surface.
10. A microwave regenerable and reusable desiccant cartridge as
set forth in claim 9 wherein said casing is fabricated from transparent
plastic which permits viewing of said desiccant from outside of
said casing.
11. A microwave regenerable and reusable desiccant cartridge as
set forth in claim 10 wherein said plastic is a polycarbonate.
12. A microwave regenerable and reusable desiccant cartridge as
set forth in claim 10 wherein said desiccant is of the indicating
type which has different colors when dry and when it has absorbed
moisture.
13. A microwave regenerable and reusable desiccant cartridge as
set forth in claim 9 wherein said cartridge comprises a first section
with a first wall and a first peripheral flange depending therefrom,
a second section with a second wall and a second peripheral flange
depending therefrom, said first flange being of slightly larger
perimeter than said second flange to receive said second flange
with a sliding fit, and detent means for holding said first and
second peripheral flanges in assembled relationship with said first
and second walls located in facing relationship.
14. A microwave regenerable and reusable desiccant cartridge as
set forth in claim 13 wherein said casing is fabricated from transparent
plastic which permits viewing of said desiccant from outside of
said casing.
15. A microwave regenerable and reusable desiccant cartridge as
set forth in claim 14 wherein said desiccant is of the indicating
type which has different colors when dry and when it has absorbed
moisture.
16. A microwave regenerable and reusable desiccant cartridge as
set forth in claim 9 wherein said casing is fabricated of plastic.
17. A microwave regenerable and reusable desiccant cartridge comprising
a casing which transmits microwave energy without being deleteriously
affected, top and bottom walls in said casing, desiccant material
within said casing, and a plurality of apertures in said top and
bottom walls for permitting communication between the inside of
said casing and the environment in which said casing is located
so as to permit moisture to pass therethrough into the inside of
said casing for adsorption by said desiccant and to permit said
moisture to be driven out through said apertures during microwave
regeneration of said desiccant, and means on said casing for spacing
said apertures on both said top wall and said bottom wall from a
supporting surface in a microwave oven when said casing is selectively
supported on said supporting surface for microwave regeneration.
Description BACKGROUND OF THE INVENTION
The present invention relates to a microwave regenerable desiccant
cartridge.
By way of background, regenerable desiccant cartridges are known.
These cartridges essentially consist of a metal box having a silica
gel therein. A plurality of apertures are located in the walls of
the box to permit moisture to pass into the box to be adsorbed by
the desiccant and to permit the moisture to be driven from the desiccant
during regeneration by heating the cartridge in an oven. This oven
regeneration takes approximately four hours at 350.degree. F. The
metal cartridge cannot be regenerated by microwaving because of
the nature of the metal.
SUMMARY OF THE INVENTION
It is accordingly the primary object of the present invention to
provide a desiccant cartridge which can be regenerated by microwaving
in a few minutes whereas the same size cartridge previously could
be regenerated only by being heated in an oven for a period of about
four hours.
Another object of the present invention is to provide a microwave
regenerable desiccant cartridge which is transparent so that indicating
desiccant therein can be viewed to determine its condition.
Yet another object of the present invention is to provide a microwavable
desiccant cartridge which is constructed in such a manner so that
a base and cover can be conveniently snapped together into a permanent
casing.
Yet another object of the present invention is to provide a microwave
regenerable desiccant cartridge having apertures in both the top
wall and the bottom wall and legs on both the top wall and the bottom
wall so that none of the apertures will be obstructured when either
the top or bottom wall is laid on a supporting surface in a microwave
oven. Other objects and attendant advantages of the present invention
will readily be perceived hereafter.
The present invention relates to a microwave regenerable and reusable
desiccant cartridge comprising a casing fabricated of plastic which
transmits microwave energy without itself being deleteriously affected,
apertures in said casing for permitting communication between the
inside of said casing and the environment in which said casing is
located, and desiccant material within said casing for adsorbing
moisture which passes through said apertures from the environment
and for being regenerated by microwave energy which drives moisture
from said desiccant material through said apertures.
The present invention also relates to a microwave regenerable and
reusable desiccant cartridge comprising a casing which transmits
microwave energy without being deleteriously affected, top and bottom
walls in said casing, desiccant material within said casing, and
a plurality of apertures in said top and bottom walls for permitting
communication between the inside of said casing and the environment
in which said casing is located so as to permit moisture to pass
therethrough into the inside of said casing for adsorption by said
desiccant and to permit said moisture to be driven out through said
apertures during microwave regeneration of said desiccant, and means
on both said top wall and said bottom wall for spacing said apertures
therein from a supporting surface in a microwave oven when said
casing is laid on said supporting surface with either said top wall
or said bottom wall facing said surface.
Other objects and attendant advantages of the present invention
will readily be perceived hereafter when the following portions
of the specification are read in conjunction with the accompanying
drawings wherein:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the improved microwavable desiccant
cartridge of the present invention;
FIG. 2 is a top plan view of the base of the desiccant cartridge;
FIG. 3 is a side elevational view of the base;
FIG. 4 is an end elevational view, partially in cross section,
of the base;
FIG. 5 is an enlarged fragmentary cross sectional view, taken substantially
along line 5--5 showing various details of the base;
FIG. 6 is a bottom plan view of the cover of the cartridge shown
in FIG. 1;
FIG. 7 is a cross sectional view taken substantially along line
7--7 of FIG. 6;
FIG. 8 is a cross sectional view taken substantially along line
8--8 of FIG. 6; and
FIG. 9 is a fragmentary enlarged cross sectional view taken substantially
along line 9--9 of FIG. 6 showing various details of the cover.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The microwave regenerable desiccant cartridge 10 of the present
invention includes a cover 11 which is snap-fitted onto a base 12
to retain desiccant pellets 13 therein. Both the cover and the base
are fabricated of plastic which will not be deleteriously affected
during the microwaving. A plastic which has been found satisfactory
is marketed under the trademark ULTEM Grade 1000 by the General
Electric Company. This plastic is also transparent so that the pellets
13 can be viewed therethrough, which is especially practical so
that the condition of desiccant pellets 13 can be observed. In this
respect, it is preferable to use indicating silica gel which is
blue when it is in condition to adsorb moisture and which turns
pink when it is saturated.
Base 12 includes a lower wall 14 having an inner surface 15 and
an outer surface 17. A peripheral flange 19 extends upwardly from
wall 14. A bordering flange 20 extends around base 14 and is essentially
coextensive therewith. Flange 19 consists of a pair of short walls
21 and a pair of long walls 22. The walls 21 and 22 merge into each
other, as shown in the drawings. A protuberance or boss 23 is located
on the outer surface of each wall 21. A plurality of protuberances
or bosses 24 extend outwardly from each wall 22. Each of these protuberances
are of the configuration shown in FIG. 5. The end of flange 19 remote
from wall 14 is tapered, as shown at 25 in FIG. 5 with the taper
leading to the protuberances 23 and 24. The flange 19 between the
protuberances 21 and 23 on one hand, and wall 14 on the other
hand, is slightly tapered, as shown in FIG. 5.
A plurality of cylindrical apertures 27 are formed in wall 14.
A plurality of legs 16 extend outwardly from the outer surface 17
of the bottom wall 14 to thereby space the apertures in the bottom
wall from a supporting surface of a microwave oven when the casing
is laid on the supporting surface with the bottom wall facing this
surface.
The cover 11 of cartridge 10 includes a top wall 31 having a peripheral
flange 32 depending therefrom which includes relatively short portions
33 and relatively long portions 34 which are joined as shown in
FIG. 6. Flange 32 is of slightly larger size than flange 19 of the
base so that it will fit over it with a sliding fit and provide
a good tight joint therewith after desiccant has been placed into
the base. Flange portions 33 have grooves 35 therein. Flange portions
34 have elongated grooves 37 therein. The cross sectional configuration
of grooves 35 is shown in FIG. 9. Grooves 37 have the same cross
sectional configuration as grooves 35.
A plurality of cylindrical apertures 39 extend between inner surface
40 and outer surface 41 of top wall 31. These apertures are identical
to apertures 27 of bottom wall 14. A plurality of legs 36 extend
outwardly from the outer surface 41 of the top wall 31 to thereby
space the apertures in the top wall from a supporting surface in
a microwave oven when the casing is laid on the supporting surface
with the top wall facing this surface.
When the cover 11 is assembled with base 12 the flanges 32 and
19 respectively, fit together with a tight fit, as expressed above.
Furthermore, during the assembling process, the tapered portion
44 of flange 32 slides over the tapered portion 25 of flange 19.
When the bottom edge 45 of flange 32 abuts ledge 47 of flange 20
the protuberances 23 will have entered grooves 35 and protuberances
24 will have entered grooves 37. Entry of the protuberances into
the grooves is by means of a cammed snap-fit. As can be seen from
FIG. 5 the surfaces 49 of protuberances 23 are at a greater slope
than surfaces 50 thereof. Surfaces 49 will be in contiguous abutting
relationship with surfaces 51 of grooves 35 and surfaces 50 will
be in abutting relationship with surfaces 52 of grooves 35. As can
be seen from FIGS. 5 and 9 the slopes of surfaces 50 and 52 are
relatively shallow to preclude the separation of the flanges 19
and 32 after they have been assembled. The relatively steep slope
of surfaces 49 permits cover flange 32 to slide over the protuberance
23 during the assembly process. While the configurations of protuberance
23 and groove 35 has been shown only in FIGS. 5 and 9 it will be
appreciated that all of the protuberances and all of the grooves
have the same cross sectional configuration.
As stated above, prior desiccant cartridges were fabricated of
metal and had holes therein which were of the size which prevented
the desiccant from falling out of the cartridge and which were sufficiently
large to permit moisture to enter the cartridge and also be driven
from the desiccant when it was regenerated in an oven. Since this
regeneration normally took approximately four hours at about 350.degree.
F., the moisture was driven out of the desiccant at a very slow
rate, and thus even though the holes were relatively small, there
was no water-vapor pressure build-up in the cartridge. Furthermore,
as also indicated above, metal could not be microwaved.
In accordance with the present invention, the casing of the cartridge
is fabricated from microwavable plastic, which permits the desiccant
to be regenerated in a microwave oven in approximately twelve minutes.
However, during this rapid regeneration, a large volume of water
vapor is generated in a very short period of time, and it has to
escape from the inside of the cartridge. If the pressure of the
water vapor is not released quickly enough, the vapor pressure within
the container will increase, which, in turn, will counter the formation
of additional water vapor. Furthermore, if the vapor pressure becomes
sufficiently high, it could create undesirable stresses on the container
itself. Accordingly, as noted above, the top wall 31 has a plurality
of outwardly extending legs 36 and bottom wall 14 has a plurality
of legs 16. Thus, when the casing is laid on the shelf of a microwave
oven with either the top wall 31 or the bottom wall 14 facing the
surface, the legs on that wall will space it from the shelf surface
so that the apertures in that wall will remain unobstructed so water
vapor may pass through these apertures as well as the apertures
in the casing wall which is not adjacent the shelf of the microwave
oven.
It is necessary that the apertures in the cartridge should be of
relatively small diameter so as to prevent passage of the desiccant
through the walls. In the specific embodiment disclosed, the apertures
are 0.060 inches in diameter. There are 196 apertures in the cartridge
which has a volume of approximately 4 cubic inches and is intended
to contain approximately 5 grams of silica gel beads which can adsorb
about 16 grams of water. The desiccant which has been used is silica
gel beads having a diameter of approximately 0.125 inches. However,
it is envisioned that other desiccants can be utilized, such as
activated clay or calcium sulfate.
While a specific plastic has been disclosed, it will be appreciated
that other suitable plastics which are not deleteriously affected
by microwaving may also be used.
It can thus be seen that the microwave regenerable desiccant cartridge
of the present invention is manifestly capable of achieving the
above-enumerated objects and while preferred embodiments of the
present invention have been disclosed, it will be appreciated that
it is not limited thereto but may be otherwise embodied within the
scope of the following claims. |