A dome-shaped baffle for an accumulator molded from desiccant material,
which baffle separates and dries liquid and vapor components of
an incoming flow of refrigerant while preventing the liquid refrigerant
from entering an outlet tube. The dome-shaped baffle forces all
of the refrigerant to contact the desiccant and has a barrier layer
attached underneath that prevents liquid refrigerant from flowing
through the baffle and directly into an inlet end of the outlet
What is claimed is:
1. An accumulator assembly comprising:
a housing having a top end and a bottom end, said top end of said
housing having an inlet opening and an outlet opening;
an outlet tube extending into said housing by way of said outlet
opening, said outlet tube having an inlet end located within said
housing, said outlet tube further having a bight portion positioned
near said bottom end of said housing, said bight portion having
an oil pick up tube and an oil filter thereon; and
unitary means for dispersing and drying a flow of refrigerant,
said unitary means being located in an upper region of said housing,
wherein said unitary means comprises a baffle positioned above said
inlet end of said outlet tube within said housing, said baffle being
molded from desiccant material, whereby said baffle functions to
deflect a flow of refrigerant and to remove moisture from said flow
2. An accumulator assembly as claimed in claim 1 wherein said
baffle is dome-shaped.
3. An accumulator assembly as claimed in claim 2 wherein said
baffle further includes a barrier on the underside of said baffle
for preventing liquid refrigerant from passing through said baffle
into said inlet end of said outlet tube.
4. An accumulator assembly as claimed in claim 3 wherein said
baffle further includes a plurality of raised sections defining
a plurality of channels therebetween for deflecting and drying said
flow of refrigerant, said plurality of raised sections having an
opening therethrough for receiving said outlet tube.
5. A baffle for an accumulator assembly wherein said baffle comprises
unitary means for dispersing and drying a flow of refrigerant in
an accumulator, wherein said unitary means includes a body molded
from desiccant material.
6. A baffle as claimed in claim 5 wherein said body is dome-shaped.
7. A baffle as claimed in claim 6 wherein said body includes a
barrier attached underneath said body for preventing liquid refrigerant
from passing through said body.
8. A baffle as claimed in claim 7 wherein said body further includes
a plurality of spaced apart raised sections defining a plurality
of channels therebetween for deflecting and drying said flow of
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to an accumulator for use
in an air-conditioning system, where the accumulator separates a
refrigerant into liquid and vapor components. More particularly,
the present invention relates to a molded desiccant baffle for drying
and directing the refrigerant.
2. Description of the Prior Art
It is common practice in today's accumulator technology to use
a baffle plate or deflector to help ensure that liquid refrigerant
does not enter the inlet end of the outlet tube. Accordingly, U.S.
Pat. No. 4474035 to Amin et al. discloses a domed baffle located
in an upper region of the accumulator housing adjacent to the accumulator
inlet opening. The liquid refrigerant enters the accumulator housing
through the inlet opening in the top of the housing and is dispersed
over the dome of the baffle toward the sides of the housing. This
creates a vertical flow down the sides of the accumulator housing.
Consequently, the vapor component of the refrigerant collects in
the upper region of the housing, beneath the baffle, and near the
inlet end of an outlet tube. The inlet end of the outlet tube is
located directly below the domed baffle plate where it is protected
from the liquid component of incoming refrigerant. Next, Amin et
al. disclose a bag containing loose desiccant particles located
in the bottom portion of the accumulator, below the baffle plate,
that is secured to the outlet tube by a strap. The loose desiccant
particles absorb any moisture that may be present in the vapor component
of the refrigerant as it passes through the accumulator.
Unfortunately, there are disadvantages associated with using a
bag for the desiccant as disclosed in Amin et al. For example, the
bag is easily damaged during assembly and testing. A tear in the
bag allows the loose desiccant particles to escape and potentially
enter the air-conditioning system where they can damage the accumulator
and other components. Furthermore, there are other disadvantages,
including attrition between individual particles that causes powdering
and packing, thereby reducing the penetrability and the effectiveness
of the desiccant. Loose desiccant also has a tendency to develop
channels where the refrigerant can flow freely without passing through
desiccant particles, bypassing the drying effects of the desiccant.
U.S. Pat. Nos. 5114584 and 5384047 both to Sheckler et al.,
attempt to overcome the problems associated with loose desiccant
particles by disclosing a filter body comprised of a molecular sieve
material. Sheckler et al. disclose combining a predetermined amount
of molecular sieve material with a predetermined amount of nylon
material and compacting the mixture into a disc or puck-shaped body.
The compacted body is heated while being subjected to pressure forming
a filter body.
U.S. Pat. No. 5440898 to Starr discloses a filter-drier core
molded from a permeable matrix including desiccant particles, a
binder, and reinforcing fibers. The reinforcing fibers are fixed
in place by the binder and impart strength and permeability to the
The filter bodies disclosed in Sheckler et al. and the filter-drier
core disclosed in Starr are products that require a flow rate of
liquid through the filter. Thus, the refrigerant liquid must pass
completely through the filter to gain the advantage of the desiccant's
In an accumulator, it is undesirable for liquid refrigerant, or
any other moisture, to exit the accumulator. Only the gaseous or
vapor component of the refrigerant should pass out of the accumulator,
because any moisture in the gaseous component will deter proper
functioning of the air-conditioning system. Accordingly, the baffle
prevents any liquid refrigerant from accidentally passing into the
outlet tube of the accumulator. The refrigerant should be dried
by the desiccant so that a minimum amount of moisture is allowed
to re-enter the air-conditioning system after collecting underneath
the baffle and passing through the rest of the accumulator.
Moreover, it is undesirable from a manufacturing point of view
to have multiple components in an accumulator assembly. Thus to
improve product cost and quality it is desirable to reduce, or limit,
the number of components that are required for efficient accumulator
operation. What is needed is an accumulator that has fewer components
than prior art accumulators, yet functions at least as efficiently
as present day accumulator systems.
SUMMARY OF THE INVENTION
The present invention is an accumulator baffle molded from a desiccant
material that functions to separate the liquid and vapor components
of incoming refrigerant while preventing liquid refrigerant from
entering the outlet tube. The desiccant material dries the vapor
component of the refrigerant before it passes out of the accumulator
via the outlet tube.
The present invention overcomes many of the disadvantages associated
with prior art accumulators and the way that desiccant material
is packaged by eliminating the need for a separate bag, or other
container, to house loose desiccant particles. The baffle of the
present invention is molded from a solid desiccant material thereby
eliminating the problems of attrition and channels normally associated
with loose desiccant material.
The present invention also reduces the number of components required
in the accumulator by combining the baffle and the desiccant, thereby
simplifying assembly and lowering manufacturing costs. The efficiencies
in assembly and manufacturing are not the only savings. Fewer components
result in lower part costs and less potential for failure, such
that not only are manufacturing costs greatly reduced, but also
part cost is reduced and product quality is increased.
The dual function component of the accumulator allows both a fixed
location of the desiccant material near the top of the accumulator
housing, and forces all of the refrigerant, liquid and vapor, to
pass through the desiccant material. The shape of the baffle can
be modified to accommodate a variety of accumulator designs.
It is an object of the present invention to separate a flow of
refrigerant into vapor and liquid components and at the same time
dry the vapor component of the refrigerant flow.
It is another object of the present invention to reduce the number
of components required in an accumulator assembly.
It is yet another object of the present invention to avoid the
drawbacks associated with loose desiccant material by using a solid
It is a further object of the present invention to provide a baffle
for an accumulator assembly molded from a desiccant material to
both separate and dry a flow of refrigerant while using fewer components
in the accumulator assembly.
These objects, features and advantages of the present invention
are readily apparent from the following detailed description of
the best mode for carrying out the present invention when taken
in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view, shown in partial cut away, of
the desiccant baffle of the present invention as assembled in an
FIG. 2 is a perspective view of a desiccant baffle of the present
FIG. 3 is a perspective view of another embodiment of the baffle
of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to FIG. 1 there is shown an accumulator assembly
10 including a generally cylindrical housing 20 that is completely
sealed except for an inlet opening 22 and an outlet opening 24 in
a top 28 of the housing 20. The inlet opening 22 accommodates an
inlet tube 60 that supplies a flow of refrigerant 15 into the accumulator
The outlet opening 24 accommodates an outlet or U-tube 30 that
includes a first leg 32 extending from the outlet opening in the
top of the housing 20 to a bottom end or lower region 29 of the
housing 20 wherein a bight portion 33 of the outlet tube is positioned.
The bight portion 33 has an oil pick up tube 37 and an oil filter
38 mounted thereon. A second leg 34 of the outlet tube 30 extends
upward from the bight portion 33 of the outlet tube 30 back toward
the top 28 of the housing 20. Additionally, an inlet end 36 is located
at the end of the second leg 34 of the outlet tube 30 and is preferably
positioned underneath a baffle 40.
Referring now to FIGS. 1 and 2 the baffle 40 of the present invention
is located inside the upper region 25 of the housing 20 is generally
domed shaped, and is composed of solid desiccant material. Further,
the baffle 40 has an opening 42 through which the outlet tube 30
passes. The outlet tube 30 is expanded within the opening 42 to
retain the baffle 40 in a position directly over the inlet end 36
of the outlet tube 30. Also, the baffle 40 is peripherally supported
by a ring 26 attached to the housing 20. Additionally, a skin or
barrier layer 48 is integrally or separately attached underneath
the baffle 40 to prevent liquid refrigerant from flowing into the
inlet end 36 of the outlet tube 30.
In the embodiment shown in FIGS. 1 and 2 the baffle 40 has a plurality
of spaced apart raised sections 44 one of which contains the opening
42. The spaced apart raised sections 44 define a plurality of channels
46 therebetween. The channels 46 direct the incoming flow of refrigerant
and aid in separating the vapor component of the refrigerant from
the liquid component.
FIG. 3 illustrates another embodiment of the present invention
in the form of a solid desiccant baffle 140. The baffle 140 has
raised sections 144 that are not spaced apart, but are contiguous,
similar to sections of an umbrella. There are channels 146 located
between adjacent raised sections 144 that serve to direct the flow
of refrigerant and aid in separating the liquid and vapor components
of the refrigerant. Again, the baffle 140 has a skin 148 that shields
the inlet end (not shown) of the outlet tube (not shown) from refrigerant
flow. An opening (not shown) for the outlet tube may also be included.
In general, the baffle is molded from a desiccant material by a
process known to one skilled in the art, such as a process that
is proprietary to Union Carbide. Their process also allows the filler
material to take the shape of and replace the skin. As an alternative,
a separate plastic skin can be molded to the underside of the baffle.
An advantage of molding the baffle from desiccant material is that
molding allows the baffle to perform the function of two parts in
one. First, the baffle directs the incoming flow of refrigerant
and prevents the refrigerant from entering the inlet end of the
outlet tube, as a typical baffle does. Second, the desiccant of
the baffle dries the fluid, thereby eliminating the need for a separate
desiccant component. Combining the baffle and the desiccant is novel
and results in use of fewer components. and therefore eases assembly
and reduces part costs.
Furthermore, the solid desiccant baffle has advantages over loose
desiccant particles contained in a bag. The solid desiccant baffle
is not easily damaged during assembly and testing as is the fragile
bag that is used to hold loose desiccant particles in prior art
accumulators. During assembly of an accumulator system, the accumulator
housing is subjected to a brazing oven at extremely high temperatures.
The solid desiccant baffle of the present invention is capable of
withstanding this high heat, whereas a fragile bag containing loose
A further advantage of the solid desiccant baffle of the present
invention is that it remains in a fixed location and cannot shift
position within the housing as is seen in prior art accumulators
that use a bag of loose desiccant particles to dry the refrigerant.
Additionally, the solid construction of the baffle maintains a
fixed path for the refrigerant as it passes over the baffle. There
is no chance of developing channels within the loose desiccant particles
that allow the fluid to bypass the drying properties of the desiccant.
In the accumulator assembly of the present invention, there is no
other path for the refrigerant to follow other than over the baffle,
where it is subjected to the drying properties of the desiccant.
The volume of the molded desiccant in the present invention is
the same as the volume of loose desiccant used in prior art accumulator
systems. The desiccant baffle provides the same amount of desiccant
as the loose desiccant in a bag, yet provides the advantages discussed
above that loose desiccant in a bag is unable to accomplish.
While two embodiments have been illustrated in the accompanying
drawings and described in the foregoing description with particular
specifics, it is to be understood that the present invention is
not to be limited to just the embodiments disclosed herein. Numerous
rearrangements, modifications and substitutions are possible without
departing from the scope of the following claims. One skilled in
the art is capable of modifying the design and shape of the baffle
to accommodate different accumulator designs.