Note: Descriptions are shown in the official language in which they were submitted.
BACKGROUND_OF T~TE _NVENTION
Related Applications
This applicati~n is a continuation-in-part of copending
application Serial No. 693l705, filed May 6, 1991, which is a
continuation-in part of U.S. Patent No. 5,050,667, issued
September 24, 1991.
Field of th~æ~r~_ tion
This invention relates to an apparatus for dehumidifying
air withi~ an enclosure.
Description of the Invention Backqround
Dehumidification apparatus are known for use in reducing
the moisture content of air within an enclosureO There are
several reason~ why it is desira~le to reduce the moisture
I content o~ the air. For example, in certain industrial
! operations, ~uch ~s the manu~ac~ure of integrated cixcuits, it
is desirable to maintain the air within the manufacturing
facility at a low relative humidity. Additionally, in
war~houses which store material subject to corrosion, it has
besn found tha~ a lower relativ~ humidity within the warehouse ¦
inhibits the corrosion oiE the material~. Dehumidifiers are
also desirable for u~e in homes where the occupants ~ind it
more comfortable when the relative humidity has been reduced.
¦ In connect:ion with air conditioning, energy costs can be
minimized through the use of a dehumidifierD
In the past, dehumidifiers have been complex apparatus
having rotzlting desiccant-contai~ing matrlc~s or having
compr~ssor~; utilizing refrigerants. Dehumidifiers of the
rotating matrix type have two air streams ~lowing
1 simultaneously in opposite directions through a duct housing
the matrix. One air stream enters the duct from an enclosure,
passes through part of the desiccant containing matrix, giYes
up its moisture to the matrix, and exit~ the dUct hack into the~
enclosure. ~ecau6e this air etream is heing dried by contact
I with a desiccant, the air stream is called the "proce~s
¦ stream", and the dried air is called "process air". A second
I air stream enter~ the duct from outside, the enclosure, passes
~ through another part of ~he dlesiccan~- con~aining matrix, picks
up moisture ~tored in that pa:rt o~ the matrix (by virtue o~
previous exposure to a process air stream), and exit the duct
back into the source of air which is outside the enclosure.
This air stream is discarded and because it regenerates the
desiccant ~or ~urther use, thle air stream is called the
"regeneration stream" or "regeneration air". While both the
process and regeneration air streams are continuously flowing
I through the de~iccant-containing matrix, th~ matl-ix is slowly
¦ rotating to expose to the process stream that portion of the
I matrix which has been dried by the regeneration stream. The
portion of the matrix exposed ~o ~he process stream must be
sealed from the portion of ~he matrix exposed to the
regeneration stream if the matrix is to be dried by the
regeneration stream. ~owever, due to the rotation of the
matrix, it i~ extremely difficult to maintain a seal between
the two portio~s of the makrix. 5uch dehumidi~iers are
¦ exempli~ied by complex duct work and many moving parts. An
example of such a dehumidifier can be found in U.S. Patent No.
I 4,134,743 ko Macriss et al.
¦ ~nother problem with dehumidifiers is that bacteria can
grow inside the associated ducts and can be blown into the
enclosure. Therefore, a need exists for a dehumidi~ier which
has a minimum o~ moving parts, ls compact and relatively
inexpensive to manufacture, and which can be easily cleaned and
serviced. The need also exists for a dehumidifier having a
duct with a ~inimal amount of curves or bends to minimize
places where bacteria can grow.
-- 2
Furthermore, the need exists eOr a dehumidifier which
efficiently utilizes energy in operation so as to reduce the
operating cost to the user o~ the dehumidifier.
j BRIEF ~MMARY OF_THE INVENTION
I The present invention, in one embodiment, combine~ in a
sinyle, relatively compact housing the necessary components to
efficiently dehumidify air within an enclosure with the
assistance of an air source outside of the enclosure. The
I apparatus includes a duct with at least four ports, two at each
' end. The ports are regulated by valves that are biased in the
closed position.
A desiccant containing, stationaxy matrix is disposed
within the duct. Al~o disposed within or without the duct is a
fan which is adapted to produce substantially axial air flow
¦ through the duct. In one embodim2nt, the fan is adapted to
produre air flow in two directions through the duct: a first
direction during a regeneration phase of the dehumidi~ying
cycle and a second direction during a process pha~e of the
I dehumidification cycle. In a second embodim~nt, two fans are
~ utilized to reverse the air ~low through the duct9 In a still
I further embodiment, a valve i~ utilized to reverse the air
i~l~w.
In the proc~s pha~e or direction, air e~ters one ~nd of
the duct~ pas~e$ through the stationary matrix and exits
through the opposite end of the duct. As the air passes
through th~ desiccant containing matrix, moisture is adsorbed
by the des:iccant wAich i~ pr~erably silica gel or is absorbed
by lithium chloride~ The air is ~hus at a lower r~lative
hum~dity when it exits khe duct.
In the regeneration phase or direction, the direction o~
air flow within the duct is reversed. Air is drawn into the
duct ~rom Zl source outside the enclo~ure, heated by a heater
and pa~ed through the desiccant containing matrix. ThP heated
- 3 -
air removes moisture ~rom the desiccant during such passage~
I After passing through the matrix, the air, having a higher
I moisture content, exits the duct through a port in the opposite
end of the duct and is returned to the source of air outside
the enclosure, i.e. is effectively discarded.
The air flow direction thxough the duct may be rev~rsed by
changing the orientation o~ the fan, i.e. by rotating the fan
about an axis perpendicular t~ the axis o~ rotation of the fan ¦
blades. Alternatively, the air ~low may ~e reversed by
interrupting rotation of the Ean blades and revers~ng their
direction of rokation. In a still further embodiment, the fan~
remain fixed in position and direction of rotation~ while a
valve reverses the direction of air flow through the matrices.
I The dehumidification process thus occurs utilizing a stationary
desiccant containing matrix thereby avoiding the problem~
associated with dehumidifiers of the rotating matrix type.
These and other advantage~ and benefits of the present
invention will become apparent from the Deæcription o~ a
Preferred Embodiment hereinbelow.
The means for heating the air is preferably a filament
heater having a relatively small mass. In this embodiment, the
heater may b2 switched off in the process phase and, due to its
6mall ~ass, will not import any significant heat to air passing
it during the process phase.
The valves are preferably mad~ of a re~ilient material,
such as a polyethylene ter~phthalate which is available under
the trademark MYLAR (of E.I. Dupont de Nemours). Such makerial
ha~ the property of being easily deformable when a slight force
is applied to it, yet r~turning to its orig.inal shape when the
forc~ i removed. In the ca~e of a MYLAR ~atarial, the
preferred thickness is about 0.007 inches (.175 mm~ 50 that the
valve may be deflected to open a port by an air flow directed
against it in a direction that would permit ~he material to
deform by bending, but, upon reversal of the air flow, the
- 4 -
" .,""~,.,,~,-.
~ valve will return to its original s:hape (i.e. flat) and thereby
¦ close against its seat. Another possible construction of the
valve i~ described in U.S~ Patent No. 4,74~,409 to Erling
Berner. I
In some applications, the ports in the dehumidifier duct
may be divided into several smaller ports which reduces the
noise produced when the valves close. One skilled in the art
I will recogniæe that the valves can be constructed in ~everal
¦ ways. For example, the valves could be spriny biased in the
¦ closed po~ition by either a coil or leaf spring. The valve~
could also be constructed so that they are biased in the closed
position by their own weight.
Additionally, we have found that through unique valve and
channel arrangements, multiple dehumidification matrices can be
! combined while sharing a single heater and two fans. The
single heater remain~ energized throughout cperation o~ the
dehumidifier thus resulting in more efficient use of energy andl
i more e~ficient dehumidi~ication. Such an apparatus has a
', unidirectional flow channel w~ich is preferably located in the
2D ¦ center of the apparatus. Surrounding the unidirectional flow
¦ channel axe at least two bidirectional flow channels, each
¦ having a stationary dehumidification matrix within the
¦ bidirectional flow channel. ~he bidirectional ~low channels
are in selectivP communication with the unidirectional flow
channel and allow air ~low selectively in opposite directions,
a process direction and a regeneration direction. ~ fan is
I located in the unidirectional ~low channel for produ~ing
! constant air flow in one direction. ~ heater can be located
I either within or without the unidirectional ~low channel ~or
I heating the air Flowing through the unidirectional flow
channelO A second fan is located within the apparatu~ in such
I a position as to produce air flow in the bidirectional flow
¦ channels in a process direction. Th~ appara~us includes a
valve Por selectively directing air ~low ~rom the
- 5 -
uniclirectional flow channel to at 1QaSt one o~ the
¦ ~idir~ctional flow channels in a regeneration direction while
allowing air Plow in the process direction through at least one
I other bidirectional flow channel.
DESCRIPTION OF THE DRAWINGS
For the pre~ent invention to be clearly understood and
I readily practiced, preferred embodiments will now be de~cribed,
by way of exampl~ only, with re~erence to the accompanying
figures wherein:
¦ Figure 1 is a diagrammatic representation of one
embodiment of the dehumidification apparatus of the present
invention in the regeneration phase;
Figure 2 is a diagra~matic representation of one
I embodiment of the dehumidification apparatus o~ the present
1 invention in the process phase;
Figure 3 is a view of the fan in a second embodiment of
the present invention in the regeneration phase;
Figure 4 is a view of the ~an in the second embodiment of
~ th~ present invention in the process phase;
Figure 5 is a diagrammatic representation o~ another
embodiment of the dehumidi~ication apparatus of the present
invention in the regeneration phase;
I Figure 6 is a diagrammatic representation o~ the
dehumidification apparatus of Figure 5 in the proc ss phase;
¦ Figure 7 is a diagrammatic representation of another
embodiment of the dehumidification apparatu~ o~ tha present
invention in the regeneration phase;
Figure 8 is a diagrammatic representation of the
dehumidification apparatus of Figure 7 in the prscess phase;
¦ Figure 9 i~ a diagrammatic representation vf another
¦ embodiment of the dehumidification apparatus of th~ present
inYention in the regeneration phase;
Figure 10 is a diagrammatic representation ~P the
dehumidification apparatus of Figure 9 in the process p~ase;
I Figure llA is a perspecti~e view of one embodiment of an
end piece of the present invention;
I Figure llB is a side view of the end piece oP Figure llA;
~igure 12A is a perspect:lve view of another embodiment o~
I the other end piec~ of the present invention;
¦ Figure 12~ is a side view of the end piece of Figure 12A.
I Figure 13 is a diagrammzltic representation o~ a multiple
matrix dehumidifier of the present invention;
I Figure 13A is an enlarged view of a portion of the
I multiple matrix dehumidifier of Figure 13;
Figure 14 is a top view of a mounting member used in
~ conn~ction with the multiple matrix dehumidifier o~ Figure 13;
Figure 15 is a diagrammatic representation of another
e~bodiment of the multiple matrix dehumidifier of the pre~ent
invention;
~igure 16 is a diagrammatic representation of another
embodiment of the multiple matrix dehumidifier of the present
invention;
Figure 17 is a cross-sectional view of the dehumidifier of
Figure 13 taken along the line XVII-XVII with portions of he
¦ housing and valve cut away;
Figure 18 is a cross-sectional view of the dehumidifier of
Figure 13 taken along the line XVIII-XVIII;
: . Figure lg is a cro~s-sectional Vi2W of the d~humidifier of
Figure 13 taken along the line XIX-XX~;
Figure 20 is a cros~-$ectional view of the d~humidifier of
Figure 13 taken along the line XVIII-XVIII with all valves
shown in the closed position;
Figure 21 is an isometric view of the valve of the present
I invention; and
I Figure 22 is an isometric view of a matrix in the form
ll
- 7
of a bed of desiccant grAnuls6 with part of the housing cut
away.
DESCRIPTION OF A PREFERRED_EMBODIMENT
Figures 13-21 illu~trate preferred 2mbodiments of the
present invention.
¦ Referring to Figures 1 and 2, one embodiment of the
dehumidi~ication appar~tus 10 of the present invenkion includes¦
a cylindrical duct ll, as ~een in Figure 1, which preferably is
straight and ha-~ openings at a first end 12 and a second end
14. The duct can be made of any suitable material ~uch as
plastic, steel or aluminum and is insulated where the hot
regeneration (or reaativation~ air is pa~sing through.
Disposed within the duct 11 is a desiccant containing
¦ ~atrix 38, which will retain the moisture in the process air.
~ The desicc:ant containing makrix 38 may consist o~E a heat
resistant material as the temperatuxe normally will reach 95C
(200~F) or higher during the regeneration phase depending upon
what type desiccant i~; used. A ceramic type material can
I easily be combined with adsorption type desiccants (silica gel,
molecular sieves, etc.) as well as with absorption type
I desiccants ~sush as lithium chloride). Metals ~uch as aluminum
¦ ~heet can also be used iP they are coated with a high
¦ t~mperature re~isting adhesive which can bond to the ~urface of
¦ the metal and ta the adsorption material.
¦ The matrix 3~ may be constructed by rolling corrugated
~aterial into a cylinder so that the corrugations Porm axial
pAsE;ageway~; through the desiccant containing matrix 3~ Por ~ir
j to flow therethrough. The corrugated material has a flat
I backing material attached. The matrix 38 can also be Pormed
. into a square if desired. The desiccant containing matrix 38
is fixedly held in~ide the duct 11 by the Prictional contact
~ with the duct 11 and may be easily removed from the dust 11 by
I application of force to one end of the matrix 38 thereby
1 8 ~
forcing the mat:rlx 38 out of the duct 11. The desiccant in the
matrix will retain moisture contained in the process air.
Another type of matrix, as shown in Figure 22, could be a
captive bed 538 of granular desiccant 540 such as granular
silica gel. The granules would preferably be less than 1/4
inch in size and would be held in a housing 542 with screens
544 and 546, covering each e~nd o~ the housing. The term
"matrix" as used herein means generally any hody of material
I that permits air ~low theret:hrough while providing contact
I surfac$~s with the air to pexmit changes in the physical
prcperties of the air to occur, e.g. a change in moisture
content, etc. Spec:iIically, the matrix includes t he two
embodiments described above.
Adjacent t o the desiccant containing mat rix 38 in the duct
, 11 is a fan 40 which produces a substantially axial air ~low.
¦ The fan could also be located outside o~ the duct but is shown
within the duct for illustrat ion purposes. The ~an is
comprised of an electric motor 41 and a plurality of blades 46.
~ One feature of the invention, which will become apparent below,
1 i~; t he ~act that if desired, only one fan c:an be required in
¦ the dehumidi~ying apparatu~ 10. The fan serves to produce
- substantially axial air flow in two directions, a ~irst
(regeneration~ direction ~rom the first end 12 to the ~econd
end 14 and a second (process) dire~tion ~rom the second end 14
to the first end lZ. As shown in Figures 1 and 2 air ~low is
r~versed by means of a control circuit 60 which i~ powered by a
power ~;ource 62. The c:ontrol c:ircuit 60 is c:onnected to the
fan by leads (not shown). ~he control circuit changes the
polarity oi~ the volt~ge applied to the motor 41 thereby
¦ reversing t:he direction o~ rotation of the fan blades 460 It
is well within the skill of one having ordinary skill in the
art to desi.gn such a circuit ~o accomplish the d~sired result
o~ reversing th~ fan blade rotation direction. The speed of
rotation of the fan can vary between the regeneration and
¦ procQss phases.
As shown in Figures 1 and 2, one way check valves 50 and
52 are pivotally connected to the f irst end 12 of the duct 11
and onP way check valv~s 51 and 53 are pivotally connected to
the second end 14 of the duct 11. The operation o~ one way
check valves 50, 51, 52 and 53 will be described hereinbelow.
Completing the de~cription of Figures 1 and 2, a heater 26
is proYided which is preferably of the electric ~ilament type
having a relatively small mass so that it cools quickly when
the current to the filament is interrupted. Because o~ ~he
filament's small mass, little heating o~ the air occurs during
I the process phase. The heater 26 is typically energized by the
¦ control circuit 60 through a lead (not shown). The heater is
, grounded ~y another lead (not shown). The control circuit 60
energizes the heater 26 during the regeneration phase and de-
I energizes the heater 26 during the process phase. It is well
¦ within the skill of one having ordinary skill in the art to
, construct a control circuit to accomplish this result. The
heater 26 is removably held in the duct li by any suitable
means such as s~rews or bolts (not shown).
In another embodiment, as shown in Figures 3 and 4; the
fan 40 is pivotally mounted by means of a pin 42 and a solenoid
44 for rotation about an axis transverse to the duct 11 so that
the fan may direct air toward ~irs$ end 12 or second end 14.
The solenoid 44 is controlled by a timer (not shown) which
energizes the solenoid 44 at a desired ti~e interval. When the
solenoid 44 is energized, it changes the position of the ~an 40
~rom the position shown in ~igure 3 to that shown in Figure 4
thereby reversing the direction of the air flow. When the
solenoid 44 is de~energized, the fan 40 returns to the position
shown in Figure 3. The rotation can ~e through any angle
I sufficient to reverse the air flow, such as ninety degrees i.e.
as shown in Figures 3 and 4, but the angle is preferably about
.. , I ,,. - . ~
. :: : : : .: ::: . ~: - , - . : :, .
" " ,, ~
: .: : - .. -:.. -, -, .. .... .
one hundr~d eighty degrees, in order to maximize air ~low
co~diti~ns within the duct.
The pivoting movement of the ~an 40 is in each direction
¦ limited by abutments 46 which ~eal the rim of th~ fan to the
1 inside of dust in order to maximize air ~low withirl the duct.
Preferably, the air flow is reversed every 0.5-5 minutes,
although any appropriate time interval may be chosen. The
solenoid i5 of the rotating t:ype and when energized rotat~s the
fan to reverse the air flow. The solenoid 44 and ~an ~0 may be
I connected to duct 11 in any convenient manner. For example,
the solenoid ~4 and ~an 40 may be conn~cted to duct 11 by a pin
(not shown) which is exposed through an access hole (not shown)
I in the duct. By pushing the pin into the duct 11, the solenoid
¦ and fan can be removed from the duct 11.
, In a third embodiment as shown in Figures 5-10, two fans
I are disposed within the duct. The fans can be placed adjacent
one another sharing the same axi~ of rotation, as shown as fans¦
140 and 14~ in Figures 5 and 60 The fans can be separated from
one another sharing the ~ame axis of rotation as shown as fans
1 240 and 242 in ~igures 7 and 8. Finally, the fans can be
I placed ad~acent one an~ther along the transverse axis as shown
¦ as fans 340 and 342 in Figures 9 and 10. The fans can be any
type suitable for producing the desired air flow such as the
axial type or centrifugal type and should be sized to be
2S capable o moving the desired volume of air. ln embodiments
where two ~ans are u~ed, a control circuit 160 is used to
selectively energize and de-energiæe the ~ans at preselected
intervals. When o~e ~an is producing air ~low in one axial
dir~ction through the apparatus 1O, the other fan i~ de~
energized so that the rotatio~ of its blades cea~es. After a
preselected perisd o~ time has elapsed, the first Pan is de-
¦ energized by the control circuit 160 so tha~ it~ blad~s cease
I to rotate and the second fan i~ energized ~y the control
circuit 160 thus pr~ducing air flow i~ the opposite axial
¦ dir~tLon through the apparatu~ 10. In the apparatua a~ uhown
in Figures 7 and 8, two additional pairs of flapper valves or
I one way check valves 102, 104~ 106 and 108 are disposed within
the duct 11, one pair 102 and 104 surrounding the first fan 240
and another pair 106 and 108 surrounding the second fan 242.
j The~e valves increase the ePficiency of the fans by directing
the air ~low to the fan which is energized.
Referring now to Figures 11~, llB, 12A and 12B, the first ¦
end 12 and ~e~ond end 14 of the duct 11 have end pieces 20 and
1 22, respeotively. In one embodiment Or the invention, thé
first end 12 and second end 14 comprise annular ring having
openings therethrough as seen in Figures llA and 12A,
respectively. It will be understood by one skilled in the art
that the openings can be of various geometries and are shown as
horizontal slots in Figure l~A and as quarter circles in Figure
12A for illustration purposes only. In some applications it is
de~ired to have several ~maller openings ~o that the valves
discussed hereinbelow will produce less noise on their closing.
The end pieae 20 has an outside surface 21 and an inside
surface 23 (Figure llB). Similarly, the end piece ~2 has an
outside surface as and an inside sur~ace 27 (Figure 12B). As
seen in Figures ll~ and llB, the openings of the end piece 20
are covered by two flexible valves, an upper valve 16 and a
lower valve 18. The upper valve 16 has an attachment edge 24.
The attachment edge ~4 i~ connected horizontally acr~s the
dia~eter of the outside surface 21 of the end piece 20 so that
; air flowing in the direction of arrow 1 in Figure llB will push
the upper valve 16 outward causing it to bend away from the end
piece 20 so that the air may flow through the opening in the
end piece 20; however, such flow will bear against lower valve
18 thereby further urging the valve into its nor~ally closed
position. l'he lower valve 18 al~o has an attachment edge 28
which is connected horizontally acros~ the diameter of the
inside surface 23 of the end piece 20, as seen in Figur~ llB.
- 12 -
When air flows in the direction of arrow 2 in Figure llB, the
lower valve 18 bends inward 80 tha~ air may f low through the
¦ opening in the end piece 20, but air flow in the direction o~
~ arrow 2 will bear against upper valve 16 thereby further urging
the valve into its normally c:losed position.
The end piece 22 as seen in Pigures 12A and 12B has
quarter circular valve 31, 32, 33 and 34 which operate in a
similar manner as valve ~6 and 18 o~ $he end piece 20. Valve
31 and 32 are attached alonq horizontal edges 43 and 45 to the
inside surface 27. Valves 33 and 34 are attached along
horizontal attachment edges ~7 and 49 to the outside surface
25. When air is flowing in the direction o~ arrow 3 in Figure
12B, the Valve 33 and 3~ bend away Prom the end piece 22 to
~ allow air to exit ~rom the apparatus. When the air flow is
I r~versed, and flows in the direction of arrow 4 in Figure 12B,
the valves 31 and 32 bend away from the end piece 22 and allow
air to enter the apparatus through the end piece 220
In operation, the dehumidifying apparatus has two phases:
I a proce~s phase and a regeneration phase. In Figures 1 and 2,
arrows 5 and 7 having dark arrowheads represent air having a
rçlatively high moisture content and arrows 6 and 8 having a
light arrowhead represent air haviny a relatively low moisture
contentD During the process phase (Figure 2), the fan 40 is
¦ adapted to provide air flow from end 14 to end 12. Air is
¦ drawn from the enclosure, in the direction of arrow 5 in Figure
¦ 2, through ~he end piece 22~ by the ~an 40. The flow o~ air
¦ pushes open one way check valve 51 and forces closed one way
I check valYe 53. The air pa~ses throu~h the desiccant
¦ containing matrix 38 and gives up its moi~ture to the desiccant
I containing matrix 38. A~ter passing through ~he desiccant
containing matrix 38, the air ~lows out through the end piece
20 in the direction of arrow 6 in Figure 2 and re~urns to the
I enclo~ure. The Plow oP air pushes open one way check valve 50
and ~orces closed one way check v~lve 52. During thi~ phase,
- 13 -
.-~. ~ .
the heater 26 is de-energized. When a preselected period of
time elapses, the air flow is reversed, thus placing the
apparatus in the regeneration phase.
In the regeneration phase (Figure 1), th~ ~an 40 i~
¦ adapted to provid~ air ~low from end 12 to end 140 Air is
drawn from the outside of the enclosure or apparatus 10 through~
the end piece 20 in the direction o~ the ~rrow 8 in Figure 1 by
the ~an 40. The flow of air pushes open one way check valve 52
¦ and pu~hes closed one way check valvs 50. The air pa~se~
through the fan 40 and is heated by the heater 26l which i6
energized during the reg~n~ration phase. The air passes
through the desiccant containing matrix 38 where it picks up
¦ the moisture which was adsorbed during the process phase. The
air pa~ses through the end piece 22 in the direction of arrow 7
~ in Figure 1, and back out to khe source o~ air outside
apparatus 10. The flow of air pushes open one way check valve
53 and pushes closed one way check valve 51.
As discussed above, air flow reversal can be accomplished
I by Pither changing the position of the fan so that flow is
I reversed as shown in Figures 3 and ~, by reversing the
¦ rotational direction of the fan blades as shown in Figures 1
and 2, by stopping rotation o~ one fan and starting rotation of
the other fan as shown in Figures 5 lO or by th~ artion of a
valve as discus~ed herein below. Because the flow of air i8
r~versed through the entire matrix 38~ the need ~or a rokating
¦ matrix to achieve regeneration is complekely eliminated. Also
eliminaked are the complex ducting, seals, and mechanism for
rotating the matrix found in the prior art.
¦ The ratio time during which the air ~low is running in the
I generation ]phase and in the reverse direction according to
Figure 2 ~p:rocess of dehumidi~ication phase) is adjustable in
dependence on the degree o~ humidiky and dehumidi~ication. The
preselected periods o~ air ~low and reverse flow can also be
dependent on temperature, relative humidity of khe air in~ide
,: ~ , , ~,, - .
.: . .
and outside the enclos~lre and fan speed; al50, the preselected
en~rgy o~ the heater depends on th~ selected values o~ khe
other oper~tion ~eatur~s. We have ~ound that a ratio of 2:1 tol
1 3:1 of process to regeneration time work~ well and is
preferable u~der many conditions.
Referring to Figure 13, ;I multiple matrix dehumidi~ier 410
is shown having a central unidirectional flow channel 411.
Within the unidirectional ~low channel is a heater 426 and fan ¦
440. The fan 440, which is mounted centrally within
unidiractional flow channel 4:L1 on a mounting member ~73 as
shown in Figure 14, produces an air flow in the direction as
shown by Arrow 407 in Figure 13. Surrounding the c~ntral,
unidirectional flow ch~nnel 411 are bidirectional flow
~ channels, designated generally as 475. Bidirectional flow
channels having air flowing therethrough in the process
dir~ction will be designated as 470 and and bidirectional flow
channels having air ~lowing therethrough in the regeneration
direction will be d~signated as 471. ~ny number of
I bidirectional flow channels 475 can surround the unidirectional
1 ~low channel 411, however, ~wo to eight bidirectional ~low
channels 475 are preferred in the practice of the invention.
For purposes o~ illustration, eight bidirectional ~low channels~
475 are shown in Figures 17~21.
Within each bidirec ional ~low channel 475 is a
dehumidifioation matrix 438. At one end D~ the unidirectional
flow chann~l 411 i~ a valv~ 450 for 6electively dire~ting air
~low from unidirectional ~low channel ~1~ into one or more of
the peripheral bidirectional flow chann~ls 471 in a direction
shown by Arrow 408 in Figure l~Ao Also adjacent that same end
of the bidirectional flow channels 475 is a ~a~ 441 ~or
producing air ~low in the direction o~ Arrow ~09O Air that
flows in the process dir~ction flows past ~an 441 and out of
the apparatus through ports 443O
~, 1, , . ~
I Va].ve 450, as best shown ln Figure 21, is de6igned EO that~
air flow is in the regeneration direction through one or more
bidirectional flow channels 471, while air through the
I remainder of the bidirectional flow channels ~70 is in the
process direction. In other words, the valve i~ designed such !
that communication is established between the unidirectional
I ~low channel 411 and one or more bidirectional flow cha~nels
1 471 while interrupting aommunicatlon between these s~me
I bidirectional flow chann~ls 471 and the ~an 441.
The valve 450 is hood-~hape~ with a circular base 452. A
rectangular opening 454 is provided on the valve 450. Each
matrix 43~ is separated from the adjacent matrix by vertical
partitions 434. The vertical partitions ~34 form openi~g~ 436
which corr~spond to the opening 454 in valve 450. Whsre
openings 436 and 454 meet, suitable sealing means such as
flexible wipers (not shown) may be employed to prevent leakage
between process and regeneration air ~treams.
' Such an apparatus permits a constant flow of process air
¦ into the enclosure while regenerating one or more matrices at a
¦ ti~e. Regeneration of two or more matrices simult~neou~ly
allows for more versatility than regeneration o~ a single
matrix. For example, when three adjacent matrices are
regenerated simultaneously, the valve 450 could be rotated so
that only the next matrix is added to the regeneration air
stream along with two of the matrices that have already been
partially regeneraked, thus providing more possibilities ~or
the ratio of regeneration cycle to process cycle ~or each
matrix. It would also he possible to regenerate two or more
matrices at a time which are not adjacent to one another, i~ ~o
desired.
The valve 450 rotakes at a pre~et interval to reg~nerate
each matrix for a desired length of time. One method oP
rotating the valve 450 is illustrated in the drawings, althsugh
one of ordinary skill in the art would know ~hat the valve 450
- 16 -
may be rotated by many diEferent methods such ag, ~or example,
gear~ or pulleys. In Figure 13, a motor 44~ is shown which
rotates a shaft 446. Motor 444 may be a conventional stepper
~ motor or a aonventional motor a~sociated with a cam for
¦ indexin~ purposes. The shaft 446 in turn rotates a base member
448 to which the valve ~50 is mounted. The base member 448 is
~ constructed such that air may freely pass therethrough. Thus,
¦ the valve 450 is rotated by the motor 444.
Figure 17 is a cross-sectional view of the apparatus
showing the individual stationary matrices 438 in the
bidirectional channels 475. Figure 18 is a cross-sectional
¦ view showing the one way check valves ~31 (de~cribed below) in
the open position to allow proces~ air into the apparatus and
¦ the one way check valves 432 (described below) in the open
I position to allow regeneration air out of the apparatus.
Figure 19 is a cross-sectional view showing the matrices 43~ in
bidirectional flow channels 475. Figure 20 is a cross-
! sectional view showing the one way check valves 431 and 432 in
¦ the closed po ition.
¦ Preferably, the apparatus is designed such that the
reg~neration air flow is taken from outside the enclosure and
exhausted to outside the enclosure and process air is taken
from the enclosure and returned to the enclosure. In Figure 13
¦ this air flow pattern is accomplished by use o~ one way check
¦ valves 431 and 432. Valves 431 open to allow proc~s air
! through but will not permit regeneration air to pass in the
¦ opposite direction. Similarly, valves 432 open to allow
reg~neration air through but will not pexmit process air to
pass in the opposite direction. Ducts ~80, 48~ and 484
terminate outside th~ enclosure for intake and exhaus~ o~
regeneration air.
Through Yarious arrangements of on~ way check valve~ and
I ducts, the location from which regeneration and process air is
taken can be altered. For ~xample, in Figure 15, ~ duct 486
~7 - j
can be used so that regeneration air is taken from the
enclosure and duct 487 exhaust~ air to out~ide the enclosure.
Valves 496 and 497 allow process air to be taken ~rom the
enclosure and valves 498 and ~99 allow regen~r~tion air to be
exhausted to outside the enclosure. Additionally, as shown in
Figure 16, ducts ~88 and 490 along with porks 492 and 494 can
be used for both intake o~ process air from outside the
enclosure and exhaust of regeneration air to outside the
enclosure.
While the present invention has been described in
conjunction with prePerred embodiments, many modi~ications and
variations will be readily apparent to those o~ ordinary skill
in the art. This disclosure and the following claims ar~
intended to cover such modifications and variations.
"
ll
- 18 -
