Note: Descriptions are shown in the official language in which they were submitted.
652.004 DRYING DEVlCE
_ACKGROVND OF THE INVENTION
The present invention relates to dryers for drying various
materials9 including hair dryers, dehumidifiers and dehydrators. Conventional
apparatus of this type normally include an air blower and a source of heat applied
to the moving ambient air and may include a desiccant. Ambient air always
includes an existing water load that reduces its ability to absorb additional water
and which consumes much of the energy required to raise the ambient air
temperature. Often, the use of heated air, particularly in hair dryers, requires
the delivery of drying air through a bonnet, which is uncomfortably warm to the
user.
The prior art includes the disclosure of a hair dryer having two
desiccant units, connected to a blower and a damper means alternately providing
communication between one of the desiccant units with Q conduit to a hair dryer
hood. A portion of the heated, dry air is alternately directed through the other
desiccant unit to regenerate such desiccant unit. During the regeneration
process, a heating element is required to heat the desiccant material to
facilitate regeneration of the desiccant material, as illustrated for example in
United States Patent No. 3,304,6~3.
1--
, y'.,`"
1~5~
1652.004 It has also been conventional to furnish dryers with a desiccant
material as illustrated in United States Patent Nos. 2,~73,~13; 2,738,592;
735,507; 2,563,042; and 2,376,095.
Additionally, it is known to provide a dual chambered gas dryer
with a bypass valve to regenerate an alumina desiccant material by recycling
part of the air through one of the dual chambers, as illustrated in United States
Patent No. 3,803,724
The eommercial dryer apparatus of the prior art have several
disadvantages, as follows: First, the desiccant material in the desiccant units is
generally densely packed, and the units have a long cycle time, i.e. from 30
minutes to several hours before alternating from the drying to regeneration
eycle. This necessitates a large amount of desiccant material, increasing the
unit cost. Further, the long cycle time causes the desiccant to become less and
less efficient, as the desiccant approaches saturation, reducing the drying
capability of the unit. The long cycle time also allows the heat of adsorption to
dissipate from the desiccant material, wasting energy and necessitating the
addition of heat energy to regenerate the desiccant. Finally, the relatively large
pressure drop associated with densely packed desiceant units, requires a costly
high powered blower operating at high static pressure to move the air through
the unit, further increasing the size and cost of the dryer.
The present invention is directed to a dryer which eliminates the
large pressure drop associated with conventional dryers, allowing it to operate at
a low static pressure, and which conserves the heat of adsorption by the rapid
cycling of the system, virtually eliminating the requirement for additional heatenergy to regenerate the desiccant.
S~27
1652.004 SUMMARY OF THE INVENTION
The present invention provides a new approach to drying various
materials, such as human hair, clothing or for dehumidifying or dehydrating
various enclosures. Specifically, according to the principles OI the present
invention, ambient air is alternately and intermittently directed through one of a
pair of desiccant columns at low static pressure. The ambient air is rapidly
cycled to the second or alternate desiccant column, before the desiccant
contained within the first desiccant column reaches staturation and reversed
before the desiccant material contained within the second desiccant column loses
its heat of adsorpotion. A portion of the dried air is directed through the second
desiccant column, regenerating the desiccant material contained therein. A
resistance heater may also be used to warm the dried air before it enters the
second desiccant column such that the adsorption time equals l:he regeneration
time.
An important feature of the invention is to provide a dryer for
material, such as human hair or clothing, which involves passing the air to be
treated over a plurality of spaced desiccant baffle assemblies, each containing a
water adsorbent desiccant to make the air more hygroscopic, and thereafter
continuously passing the dried air over the wet material to be dried ~mtil such air
has absorbed the desired amount of water therefrom. The desiccant baffle
assemblies, which contain loosely packed desiccant material, create a low
pressure drop, providing sufficient air flow at low static pressure. A further
feature is to render the ambient air more hygroscopic by removing the existing
waterload therefrom and using such air at ambient temperature to dry materi~ls
with or without heating.
1652.004 A further feature of the invention is to employ, alternately, ons
of the pair of desiccant columns defining passages to remove the moisture in theexisting ambient air in a continuous regenerative system, whereby the heat of
adsorption is retained in the columns by rapid cycling. ~y rapid cycling betweenthe columns, the desiccant material in either column is not allowed to reach
more than 10% of its saturation load and the retained heat of adsorption is the
exact amount of energy required to regellerate the desiccant material contained
in the column without additional heat energy.
A further feature of the invention includes application of heat to
the dried air before it is passed the material to be dried and over the partia]ly
saturated desiccant. In a hair dryer, the dry air would otherwise feel cold to apatron's head so the heater is provided primarily for comfort. The heating of the
dry air is also more energy efficient, since no energy is used to heat the original
water load which nas already been removed with the passage of the air over the
desiccant material. The capacity of the heated dry air for absorbing water has
beerl increased. A further reduction of the drying time is achieved if heat is
applied to the dried air. The slight warming of the dry air is required to have
regeneration time equal adsorption time in a rapid cycling system with no other
impetus.
The low pressure requirements of the dryer of the present
invention permits the use of a relatively inexpensive low pressure blower. The
low pressure drop allows the system to operate at a low static pressure,
approximately 0.5 inches of water. Ambient air delivered from an inlet plenum
passes through one ô the desiccant columns into an outlet plenum having a
restricted outlet for the delivery of dry air therefrom. The restricted outlet
produces a back pressure in the outlet plenum, whereby a portion of the total
airflow, approximately ten percent, is recycled in the reverse direction, through
a second column for passage over the spaced baffle assemblies of the second
desiccant column, regenerating the desiccant material within the baffles before
exhausting to atmosphere.
_~_
~ ~5~
1652.004 A further feature of the present invention includes the use of ~
valve means, such as opposed poppet .ralves, in combination with 6 pivotal
damper. The valves are ~ctuated by the pivotal damper, which is adapted for
movement between ~ first Qnd second position~ such that the pivotal damper
controls the direction of slightly pressurized air from the inlet plenum to one o~
the desiccant columns. In either position, one of the poppet valves is closed and
the other is open, so that a portion of the air returning from the outlet plenum, is
recycled in the opposite direction, over the other of the two desiccant columns
for regenerating the desiccant material therein, before exhausting to
~tmosphere.
There is further employed a damper actuating means, such as a
cam timer, for relatively r~pid cycling, ~pproximately one to 1.5 minutes per
column. By rapid cycling, the heat of adsorption is retained in the desiccant tofacilitate regeneration of the desiccant material and provide much dryer air
since the desicc~nt only approaches ten percent saturation. Thus~ r~pid cyclîng
greatly reduces the amo~nt of desiccant required, thereby reducing the cost of
the drying device.
These and other objects will be seen from the following
specific~tion and claims in conjunction with the appended drawing.
Thus the present invention provides a dryer comprising an
enclosed housing including an air inlet and an air outlet; opposed first
and second flow desiccant bed ducts on each side of said inlet and outlet;
and an inlet plenum located between said inlet and said opposed flow ducts
and an outlet plenum located ~etween said outlet and said opposed flow
ducts. The inlet and outlet plenums communicate through ~he flow ducts.
A valve door is pivotally supported within said housing and
it has one end extending across the inlet to direct air received from said
.~
~8S~7
inlet into one of said flow ducts in a first pivotable position and
into said opposite flow duct in a second pivotable position. There is
a door actuating means intermittently pivoting said valve door
between said first and second positions to alternately and intermittently
direct air into one of said first and second flow ducts; and blower means
directing air into said inlet.
Each of said flow ducts comprises perforated baffled assemblies
of loosely packed desiccant material having a low pressure drop across
each baffle assembly. There is a heater means, positioned within the
outlet plenum in the air path, adapted for heating the dehydrated air
passing through the outlet plenum to render the dry air more hygroscopic
for increased drying of the air passing through the outlet and the air
returning through the other of the flow ducts for rapid regeneration of
the baffle assemblies.
There is a valve means in the inlet plenum which alternately
directs air received from one of said flow ducts out of the housing.
The blower means directs air into the inlet. The valve door and the
door actuating means alternately and intermittently directs the air into
one of the flow ducts, into the outlet plenum, and a large portion of
the air out of the outlet, said outlet being a restricted opening and
creating a back pressure in the outlet plenum directing a portion of
air received from the opposed flow duct into the opposite flow duct;
and said valve means directing said portion of sir received from ~he
opposed flow duct out of the housing.
,. .
~ ~5a-
~s~
DESCRIPTION OF THE DRAWING
-
Figure 1 is a front perspective view of a hair
dryer in accordance with the present invention.
Figure 2 is a fragmentary plan section thereof for
the delivery of low static pressurized ambient air alternately
thxough a pair of desiccant columns for delivery through a
restrictive air outlet port, and for the partial return of a
portion of the dried air to the other of the pair of columns,
for dehydration and xegeneration of the desiccant material
therein~
Fi~ure 3 is a fragment cross-sectional bottom view,
of Figure 2.
It will be understood that the drawing illustrates
a hair dryer as one preferred embodiment of the invention and
that other embodiments and uses are contemplated wi~hin the scope
of the claims hereafter set forth.
6--
~185~27
1652.004 DESCRIPTION OF THE PREFERRED EMBODIMENT
The dryer of the present invention, generally designated 10,
includes an enclosed dryer housing 12, blower 14, and an air diffusing bonnet 16.
Bonnet 18 is connected to housing 12 by an outlet conduit 18 and connector
pipe 20. In the disclosed embodiment~ an air diffusillg bonnet 16 is illustrated,
but it should be appreciated that the present invention may be utiliæed for drying
various materials such as hair, clothing, or for dehumidifying or dehydrating
various enclosures, or in conjunction with air conditioning.
Housing 12 has a front wall 22, rear wall 24, top wall 26, bottom
wall 28 and two side walls 30. Front wall 26 includes an inlet port 32 and rear
wall 24 includes a restricted outlet port 34. Housing 12 contains opposed first
and second desiccant columns 36 and 38 on each side of inlet port 32 and outlet
port 34.
A pair of longitudinally spaced partitions 40, 42 are spaced
inwardly of rear wall 24 and front wall 22, respectively, extending between the
top and bottom walls 26, 28, defining within housing 12 air inlet plenum 44
communicating with inlet 32, and outlet plenum 46 in communication with
restricted outlet port 34, see ~igure 2.
A plurality of spaced desiccant baffle assemblies 50 are c-~ntained
within first and second desiccant columns 36, 38. As illustrated, the baffle
assemblies 50 are removeably mounted within the desiccant columns 36, 38 in
grooves S2. Grooves 52 are formed in partitions 40 and 42 in conj~mction with
vents 48. Inlet plenum 44 and outlet plenum 46 communicate through first and
second desicc~ant column 36, 38 by way of vents 48, see Figures 2 and 3.
~S~7
1652.004 Baffle assemblies 50, in the disclosed ernbodiment, are
constructed of wire screening 54, for example 1/8 inch mesh aluminum wire
containing loosely paclced desiccant. A suitable desiccant is activated aluminumoxide9 referred to as alumina, in the forms of beads or pellets having a size which
would not pass through a screen mesh of Q.25 inches.
While other desiccants may be employed, such as granular silica
gel) it is contemplated that the preferred desiccant is a porous aluminum oxide
of a particulate form and preferrably in the form of beads to facilitate the
passage of ambient air over and through the baffle assemblies 50.
A valve damper 56 is pivotally mounted to partition 40 between
first and second desiccant columns 36, 33, within ehamber 57, by pivot hinge 58.~amper 56 has one end extending across the inlet port 32, directing ambient air
received from inlet port 32 into one of the desiccant columns 36, 38 in a first
pivotal position and into the other column in a second pivotal position. Stops 60,
attached to front wall 22 on each side of inlet port 32, limit the degree of
pivoting of damper 56. An intermittently operable power means, such as a
solenoid 90, pivots darnper 56 between its first and second positions to
alternately and intermittenly direct air into desiccant columns 36 and 38.
Solenoid 90 is connected to damper 56 by two lever arms 96 and 980
In the disclosed embodiment, the solenoid 90 is a Dormeyer
pull type solenoid, 115 volts AC, 60 HZ, 0.6D amps. The solenoid is connected
into an electrical power circuit, which includes repeat cycle timer 92 and a
power source 94. The timer in this embodiment is a Dayton Cycle Timer Model
2E130, whieh may be set in the illustrative embodiment for 1.5 minute time
cycles. As ~n alternative, a continuous 1 or 1.5 RPM electric motor, such as a
Dayton, Model LR 31462-3048 may be used in combination with a Geneva gear
assembly, which causes the damper to cycle at 1 or 1.5 minute intervals. The
particular time cycle will depend on several factors including the amount cf air
flow.
%~
1652.G04 ~ valve means, such as a pair of opposed poppet or butterfly valve
assemblies are located in inlet plenum 4~ fo~ alternately directing air receivedfrom one of the desiccant columns 36, 38 out of housing 12. In the disclosed
embodiment a pair of opposed poppet valve assemblies are illustrated. A first
poppet valve 66, including a rod 68, is located on one side of inlet plenum 4~L to
direct the air received from first dessicant column 36 through exhaust opening 70
and out of housing 12. Opening 70 is formed in housing side 30. Poppet valve 66
is supported within inlet plenum 44 by support bracket 72. A spring 74 biases
valve 66 against opening 70 in a normally closed position. ~ second poppet
valve ~6, including a control rod 783 is located on the opposite side o~ inlet
plenum 44 to direct the air received from second desiccant column 38 through
exhaust openin~ 80 out of housing 12. Opening 80 is formed in side 30. Second
poppet valve 76 is supported within inlet plenum 44 by support 82. A spring 84
biases valve 76 against opening 80 in a normally closed position.
As schematically shown in ~igure 2 an air blower 14 is connected
to inlet port 32 and inlet plenum 44. A suitable air Mower is sold by Fasco
Industries, Inc.3 Model 002101X05, operating at 150 volts A~, ~0 H7, 1.45 amps.
The air blower is adapted to deliver ambient air at approximately 120 cubic feetper minute and create a static pressure of approximately û.5 inches of water.
An electric resistance heater 88, such as a cal rod heater or
nichrome wire, extends into outlet plenum 46 in the path of movement of dry air
therethrough and is adapted to heat the dry air passing into outlet plenum 46.
The air then passes through restricted outlet port 34 and outlet conduit 18,
connected to housing 12 and at one end m~unting the dry air diffusing bonnet 16.Mllltiple heater elements may be employed as schematicaUy shown at 88
delivering 2bo watts to 14û0 when watts energized singularly or combined. For
illustration, a suitable hleater element is sold by Hartford ~:lement Co., Model10350. The electric resistance heater 88 is interposed in a circuit which includes
normally open switch 100 connected to a suitable power source 102.
~5~a~7
1652.004 The principal purpose o the heater 88 in the disclosed hair dryer
of this invention is to warm the air exiting outlet port 3~, increasing the comfort
of the user. It will be wlderstood however that the heater also reduces the
regeneration time requirements of the desiccant, making the dryer more
eff icient. It has also been found that the elimination of the hea~er in the
disclosed embodiment will eventually result in a loss of regeneration capacity.
The preferred embodiment therefore includes a low capacity heater in the outlet
plenum 46. The prior art however requires heating of the saturated desiccant
material, which requires substantially more energy.
For some operations of the present hair dryer, control switch 100
to electrical power source 102 for the heater 88 is left off. Dry air without
heating moves through the restri~ted outlet port 34 to bonnet 16. As desired andon activation of the switch 100, electrical power is provided to the heater 88 for
heating the dried air to the extent needed.
~chematically shown in Figure 1 is one means by which the
present dryer may be used within a room area such as in a beauty parlor or in the
home. When the present air dryer is utilized as a dehumidifier or for providing
dried air to the inlet of an air conditioner, or for drying clothes, the respectiYe
exhaust openings 70 and 80 are extended through a building or room wall. Thus,
the dried air picks up water during regeneration of the desiccant and is exhausted
to the outside of the room or building wall maintaining low humidity therein.
--10--
~5~
l652.004 OPERATION
As illustrated in Figure 2, blower 14 blows ambient air at
relatively low static pressure through inlet port 32 ;nto inlet plenum 44.
Damper 56, in a first position, directs ambient air into second desiccant
column 38 and over desiccant baffle assemblies Sû, contained therein9 making the
ambient air more hygroscopic by removing the existing water load by adsorption.
Exhaust opening 80 is closed forcing aU the air flow through second desiccant
column 38. Dry air flows out of second desiccant column 38 into outlet
plenum 46 and passes over the electric heater 88 which may be energi2ed.
The restricting outlet port 34 creates a differential pressure or
back pressure within plenum 46, which causes a portion of the dry air therein to
flow through the first desiccant column 36 in the opposite direction to the flow
through second desiccant. column 38. The small flow of dry air is sufficient to
remove any water whic h was collected by the desiccant material in b~ffle
assemblies 50 contained therein from the previous passage of air therethrough,
thereby regenerating it and continuously flowing through the exhaust opening 70
to atmosphere.
After a specific period of time, such as for example 1 or 1.5
minutes in a particular application, damper 56 is alternated to its second position
as shown in phantom in Figure 2. Damper 56 and poppet valves 66, 67 are
positioned to cause air flow through first desiccant column 36 while blocking
ambient air flow through second desiccant column 3S.
Exhaust opening 70 is then closed, forcing all the ambient air flow
through first desiccant column 36, and exhaust opening 80 is opened to
atmosphere, allowing regenerativ-e air to flow through second desiccant
column 38 and out of housing 12 through exhaust opening 80.
1652.004 In ~he case of commercial hair dryers, less energy will be
consumed for facilitating air conditioning because less heat will be released into
the facilities ambient air. The process of obtaining hygroscopic air to dry other
materials, such as clothing, is the same with respect to components for the
application of dry air directed over a wet material other than hair. The presentembodiment may also be employed for dehumidfying enclosures such as rooms or
buildings which involve the use of refrigeration for air conditioning. Thereforethe above described air dryer may be employed to regulate the relative humidity
of enclosures that are subject to a higher relative humidity than desireable.
The present dryer may be ernployed for any drying system, other
than hair drying, as for example, the drying of clothes or for dehumidifying a
roorn area. The present dryer reduces energy consumption by utilizing the heat
of adsorption retained on the desiccant material to facilitate regeneration. In
addition, heat is applied to air already dried passing through the desiccant
columns 36 or 38 alternately after the water load has been removed from the air
so that regeneration time equals adsorption time.
The cycle of operation of the present hair dryer or other air dryer
is automatic and continuous for the delivery of dry air to the outlet plenum 46
and the recirculation of some of the dry air for regeneration and dehydrating the
desiccant material within the respective perforated baffle assemblies 50.
The use of the present dual columned system alternately utilizing
the desiccant contained within a pair of desiccant columns 36, 33 for drying theair and for alternately drying the desiccant material is a continuous process.
-12-
Z7
1652.004 This invention may be further developed in the scope of the
following claims. Accordingly~ the above specification is to be interpreted as
illustrative of only a single operative embodiment of this invelltiorl~ rather than
in a strictly limited sense.
I now claim.
