Note: Descriptions are shown in the official language in which they were submitted.
BACKGROUND OF THE I~VENTION
It has been found that pressurized air can be fractiona!ized by
removing various elements therefrom through tna us~ of mo1ecutar sieves.
Molecular sieve separators such 3S disclosed in U. S. Patents 2,944,62 "
3,280,536 and 3,142,547 disclose the use of molecular sieve materials havlng
an Angstrom pore size of approximately 5 and which are capable of prodlJcing
an oxy~en enriched product fluid from pressurized air. In such separators
it is the usual practice to employ several beds of molecular sieve material.
Whi1e one bed is being desorbed another bed,through the operation of
control valves, is sequentially presented with a source of pressurized
air to establish a continuous supply of tne oxygen enriched product fluid.
In beds of adsorptTon materiat disclosed in the prior art
wnicn have substantially tne same cylindrical configuration, it has been
found that the particles of adsorption material closest to the entrance
port through which pressurized air is presented, adsorb tne majority of
nitrogen in tne production of the oxygen enriched product fluid~ ,hus,
the particles of adsorption material adjacent the exit port are not
effectively utilized in the production of the oxygen enriched product
fluid.
In addition, it was discovered that the efriciency of such
molecular sieve separators is also dependent upon temp~rature. F,om
experimentation it has been determined that the most effective of separa~
tiGn occurs when both the pressurized air and beds of adsorption material
are maintained at a temperature of about 80F, Unfortunate1y, wh2n
molecular sieve separators are used in aircraft the temperature in unpres-
surized aircraft cabins can reacn -65F at altitudes approaching 30,00
feet. Under these condi.ions, thereafter the efficiency of such prior
art molecular separators is greatly reduced and tne production of tne
oxysen enricned product fluid in such airsraft 1, essentially elIminated
at an altitude ~/n~n a pilot needs oxy~en the ~ost.
~ ~37~
I have devised a molecular sieve separator system for use in
aircraft having a substantially uniform amount of adsorption
of an element per unit of fluid flow of a fluid mixture by
each particle in a bed of adsorption material over the entire
altitude operating ranye of an aircraEt.
According to the present invention there is
provided a material separator system having a source of
pressurized fluid mixture and a first container having a
first separator chamber connected to a second separator chamber,
the first and second separator chambers each holding a quantity
of adsorption material to create a firs~ bed. A second
container has a third separator chamber connected to a
fourth separator chamber, the first and fourth separator chambers
each holding a quantity of adsorption material to create a
second bed. Supply conduit means is provided for connecting
the source of pressurized fluid mixture to the first and second
containers. Heater means is associated with the supply
conduit means for maintaining the pressurized fluid mixture
within a predetermined temperature range. Valvè means is
connected to the supply conduit controlling the communication
of the source of fluid mixture to one of the first and second
containers where an element in the fluid mixture is adsorbed
in the particles to produce a product fluid while a purged
fluid removes the elements from the particles in the other
of the first and second containers by flowing to the surrounding
environment.
In a specific embodiment of the invention each of
the first and second containers has an entrace flow distribution
chamber which directs the pressurized air into a large diameter
section of a material retention chamber. The cross-sectional
area of the material retention chamber varies from the large
diameter section at the entrance flow distribution chamber
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;~,
3'^,'~ ~
to a smaller diameter section adjacent an exit flow distribution
chamber. The pressurized fluid mixture, after being presented
to one of the first and seconcl containers, flows from the
entrance flow distribution chamber into the large diameter
section of the material retention chamber. The individual
particles of adsorption material adsorbs at least one element
from the fluid mixtures at a rate substantially proportional
to the rate of flow of the fluid mixture therethrough.
The cross-sectional area of the smaller second diameter section
and the length of the material retention chamber are selected
to assure that substantially the entire element is removed
from the fluid mixture before leaving the exit flow distribution
chamber as a product fluid. An output conduit connects
the exit distribution chamber to a storage container for
retention of the product fluid. As the product fluid passes
from the exit flow distribution chamber, a portion thereof,
which forms a purge fluid, is diverted from the output conduit
into the exit flow distribution chamber in the other of
the first and second containers. The purge fluid is
directed by this exit flow distribution chamber into the
small second diameter of the material retention chamber in
this container. The purge fluid expands as it flows through
this material retentioh chamber and desorbs any of the element
from the particles of adsorption material. The purge fluid
and desorbed element pass into the entrance flow distri-
bution chamber before entering a relief conduit connected thereto.
The relief conduit is wound around the supply conduit and acts
as a heat exchanger to condition the fluid mixture .in the supply
conduit by increasing the temperature thereof. The purge
fluid and element flow out of the relief conduit and is
directed by an insulating shroud to provide an external
heat source for maintaining the first and second containers
withina predetermined temperature range. After a preset time
tm/~".
3~, 5'~
or when a predetermined pressure resistance is created in the
bed of adsorption material in the first container, the pressur-
ized fluid mixture is presented to the other of the first
and second container and the production of the product fluid
initiated therein while the bed of adsorption material in the
one of the first and second containers is regenerated by
a purge fluid.
It is an object of this invention to provide
a fluid separator system with a container for retaining a
fixed quantity of adsorption material wherein each
particle of adsorption material adsorbs substantially the
same amount of an element per unit of flow from a fluid mixture
during an operational time period.
These and other objects should be apparent from
reading this specification and viewing the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a schematic illustration of a
molecular sieve separator system made according to the principles
of this invention.
Figure 2 is a sectional view showing a container
having interconnected first and second beds for holding
a fixed quantity of adsorption material;
Figure 3 is a section view of a secondary variable
area container for retaining the adsorption material of a
molecular sieve separator system;
Figure 4 is a graph showing the adsorption efficiency
of a molecular sieve separator with changes in temperature of
- the surrounding environment; and
Figure 5 is a graph showing the operation of a
molecular sieve separator with a temperature control for main-
taining the separator ata substantially uniform temperature ir-
respective of the temperature of the surrounding environment.
tm/'~ -5-
3~
DETAIL,ED DESC~IPTI~N OF THY, I~lVFNTION
The molecular sieve separator system 10 shown
in Figure 1 has control valves 64 and 68 connected to a
~urce of pressurized air or other fluid nixture th~ugh a
supply conduit 12. Control valves 64 and 68 are sequentially
activated to supply first and second containers 14 and 16,
respectively, each of which contain an adsorption material, with
pressurized air. The adsorption material in containers 14 and
16 adsorbs at least one element (nitrogen) from the pressurized
air to produce a product effluent (oxygen enriched air). The
product effluent is transmitted to a storage container 20
for use by a recipient as needed.
A portion of the product effluent produced in the
first and second containers 14 and 16 is diverted from being
communicated to the storage container 20 and is communicated
as a purge fluid to the container 14 or 16 not receiving the
pressurized air. The purge fluid enters the container at a
low pressure to desorb any of the element contained therein
from the adsoprtion material. ~hereafter, the purge fluid
and desorbed element flow to the surrounding environment as
an exhaust fluid. A shroud 24 which surrounds the moleGular
sieve separator system 10 directs the exhaust fluid over the
first and second containers 14 and 16 to maintain the
temperaturethereof within a predetermined range irrespectively
of the temperature of the surrounding environment:
In more particular detail, the supply conduit 12
is connected to a chamber 26 of a heater member 28. An
electrical resistance coil 30 located in chamber 26
is connected by lead 32 to ground 34 and to a terminal of an
electronic control 36 by lead 38.
A temperature sensor 56 in chamber 26 has a tip
58 which extends through housing 28 to continually sense the
tm/ -6-
3~
temperature of the fluid mixture in chamber 26. A signal
representative o~ the temperature in chamber26 is carried
through lead 50 to the electronic control 36. Whenever the
temperature in chambe.r 26 reaches a preset temperature, the
communication of electrical energy from the electronic control
36 through lead 38 i.s interrupted and resistance coil 30
rendered inoperative.
In addition, a temperature controller or thermostat
40 located within shroud 24 is connected to a solenoid operated
bleed valve 19 through
tm/l -6a-
`',`;-'`
~-~.Z375~
the electronlc controller 36. The temperature controller or thermostat 40
senses the temperature wlthin the shroud 24 and supplies the ~lectronic con-
troller 36 with a temperature st~nal ~Ihenever the temperature within the
shroud 24 falls below a predetermined value. The temperature sTgnal 1~
processed by the electronlc controller 36 whTch thereafter supplies the
solenold operated b1eed valve 19 ~ith an electrical signal through lead~70.
Activation of solenotd operated bleed Yalve 19 proportionally allows
pressurized air whlch has beén heated 1n chamber ~6 of the heater member 28
to en~er the shroud 24 and maintatns the temperature ~herein within a
predetermined temperature irrespectTvely of the temperature of t~.e envirori-
ment surroundTng the shroud 24.
In more particular detail, the te~perature controller or
therrrostat 40 has a bT-metal strTp 48 one end of wnich is ftxed to a
housing 42 to position the other end ;2 over terminâl 44 connected .o
ground 34 by lead 39. The housing 42 has a series of openings 46 .here-
~hrough whTch perrnits aTr within the shroud to pass,wi.hout substantial
interference, into contact with the bi~m~tal strip 48. The bi-metàl strip 48
responds to the temperzture of the air and at a preset temperature deflec~s
to form a bridge between terminals 44 and 50 and close an electrlcal circuit
between ground 34 and the electroniccontroller 36 through ieads 39 and 54. me
closure of thi~ electric circuit is the temperature sig~al that operates the
electronic controller 36 to activate the solenoid bleed valve 1q and allsw
warm pressurTzed air to enter the shroud 24.
The pressurtzed fluld mixtur or air flows from cnamber 26 at
a mTnTmum temperature controlled by sensor 56 to tee connection 18 for
dlstrTbutTon along branch condult 62 to the first control valve 64 or alons
branch conduit 66 to the second control valve 68~ The contro! valves S4
and 68 respond to an electr1cal sTgnal from electronic con~rol 36 to
select the flow path for the pressurized fluid mixture .o either the flrst
contalner 14 or second container 16.
7~
~,
3~J 5'~
Control valve 64 has a housing 72 w1tn a control chamber 74
10cated thereln. A first port 76 connects the control chamber 74 wlth
branch conduit 62 going to tee 18 while a second port 78 connects the
control chambsr 74 with conduTt 80 golng to the fTrst contalner 14. A
wall 82 separates the control chamber 74 from an atmospherTc chamber 84.
A conduit 86,whTch connects the atmospheric chamber 84 to the surrounding
environment, could be spirally wound around a portion of the supply
condult 12, as shown in Figure 1, to imparS a th~rmal reaction tnrough
conductance to the pr_ssurized fluici mtxture or air flowTns tn the supply
conduit 12 or merely com~unlcat2d to the inte.ior of the shroud 24.
A plunger 88 located in coTl 92 of solenoid 94 has a stem 90 that
extends through gutde or bearing wall 96 into the control cnamber 74. A
first poppet 98 attached to the stem 90 Is located adjacent the first por,
76 while a second poppet lO0 att~ched to the ste~ 90 is located adjacent
an opening 102 that connects the control chamber 74 ~Iith atmospheric
chamber 84. A spring 104 acts on the plunger 88 and urges the first
poppet 98 toward a seat to prevent fluld communication between tne branch
condult 62 and the control chamber 74 wnenever cotl 92 is deactivated.
The deactivation of coll 92 is controlled by an electrical sisnal com~uni-
cated through lead 106 from electronlc control 36.
- Similarly, control valve 68 has a houslng lC& w;.h a control
chamber 110 located therein. Control chamber 110 has a First port 112
connected to branch conduit 66 and a second port 114 for connecting the
control cnamber 110 wlth conduit 116 going to the seccnd container t~
Control chamber 110 is separated from an atmospheric chamber 118 by a
wall 120, A conduit 122 which connects the atmospneric cha~ber 118 to the
surrounding environment can also be spirally ~ound around a portion of tns
supply conduit 12 to impart a thermal reactton through conductance wltn
the pressurized fluid mixture or alr flowtns In the supply conduit 12.
A plunser 124 located In coil 126 of a solenoid 128 has a stem 13
g
3'~
that extends tnrough a guide or bearing wall 132 Tnto the control chamber
110. A ftrst poppet 134 attached to the stem 130 is located adjacent the
first port 112 while a second poppet 136 attached to the stem Is loca.ed
adjacent opentng 138 that connects the control chamber 110 wlth the
atmospheric chamber 118, A sprtng 140 acts on plunger 124 and urges the
first poppet 13~ toward a seat to prevent communication between branch
conduit 66 and the control chamber 110 whenever coil 126 is deactiv3ted,
Deactivation of coil 126 is controlled by an electrical signal transmitted
from electronic controller 36 through lead 142.
The first and second contatners 14 and 16 are identtcal and
therefore only the first container 14 is described in detail on Figure 2.
The ftrst container 14 has a cylindrical housing 144 with ftrst
and second end caps 146 and 148 connected thereto by fastener member 150
to establisn a sealed container 14. A shoulder 158 holds the disc
or plate 152 away from end cap 146 to establTsh a cha~,ber 164~ A plurali,y
of openings 160 and 162'located theretn to'allow substantially free com-
munication therethrough to chamber 164. The first dtsc or plate 152 and
end plate 146 cooperate with housing 144 to define the flow chamber 164
adjacent end 146. A sleeve or tubular member 16~ has a first end 170
2~ positioned on rib 168 on the second end cap 148 and a second end 172 with
a seal 174 located thereon which engages disc 1~2 to establish chambers
176 and 178 in contatner 14.
A second disc or plate 180 which surrounds tubular member 166
cooperates with the cylindrical housing 144, the first disc 152, and tubu!ar
member 166 to define the ltmits of chamber 176, A sprtng 182 located
between end cap 148 and second disc 180 urges tne second disc t~0 toward
the first disc 152 for retatntng a fixed quantity of adsorptton matertal
10cated in chamber 176 at substantia11y the same denstty during botn
adsorption and desorptton in a cycle of operatton, The second dtsc 180
has a pluraltty of openings 184 located theretn to provtde a plurality of
3 J ~i~
flow paths between flow dTstributlon chamber 186 and cnamber 176. An
entrance port 188 connects the end cap 148 wlth conduTt 80 com7ng from
-the control valve 64.
A third disc 190 aligned on bolt 156 of the fastener member 150
is located in the tubular member 166. A sprlng 192 located between
rib 168 on the end cap 148 urges the third disc 190 toward tne first
dlsc 152 to deflne the size of chamber 178. Spring 192 provides a constant
force on the quantity of adsorption material located in cnamber 178 to
substantially match the density of the adsorption materi31 in chamber 176.
The third disc 190 has a plurality of openings 194 tnerethrough to provide
substantially unrestricted flow communlcation between chamber 178 and flow
chamber 196 located adjacent passage 198 of port 200 in end cap 148. .
- In addition, the second end cap 148 has an annular depression
or groove 202 located thereon. Bolt 156 which projec.ts thrcugh opening 206
in the second end cap 148 bxtends into the depression or groove 202. A
nut 204 attached to bolt 156 is protected from damage by belng located In
the groove or depression 202. When l~ut 204 and bolt 156 are torqued to a
pr~set tension, seals 174, 206, 207~ ând 210 are seated to provide a sealod
contalner 14.
Port 200 on container 14 is connected to storage container 20
through product condutt 212. A check valve 214 In conduit 212 prevents
the flow of fluld from the storage container 20 baok into container 14.
However, product condult 212 is connected by an intermediate conduit 220
to product conduit 216 connecting port 218 of container t6 sYith stor3ge
contalner 20. A restr7ctlon 222 in the intermediate conduit 220 limits
the amount of product fluid that flows through the interrr,edlate ccnduit 220.
Similarly, a check valve 224 located in product conduit 216 prevents tne
flow of the product fluid from storage con~ainer 20 back into onta ner 16.
MODE OF OPERATION OF THE INVENTION
Before an alrcraft equipped witn a f1uld separator systern 10
-10
~ ~ ~ 3 5 ;~
shown in Fi~ure 1 takes off frcm an air field, electrical switch 226
is switched ON to allow electrical energy to flow frc~m source 228 to
the electronic control 36. Thereafter~ the electronic control 36
simultaneously transmits electrical signals to a pressurized supply
control valve 230, and one of the control valves 64 or 68.
me electrical signal opens the pressurized fluid supply
control valve 230 and allows pressurized fluid mixture or air to flow
in supply conduit 12. As long as the tempercature of the fluid
downstream of heater 28 as measured by probe 58 is above 80F. or some
other preselected temperature, electrical coil 30 in heater 28 remains
in the OFF state. Hawever, whenever the pressurized fluid temperature
downstream of the heater 28 as measured by probe 58 is below 80F. or
sc~e other preselected temperature, the coil 30 receives electrical
current frc~n the controller 36 to heat the fluid mixture in chamber 26.
In addition, if the temperature within shroud 24 as measured by
thermostat 40 is below 80F. or some other preselected temperature,
end 52 of the bi-metal strip 48 engages terminal 44 and forms a
bridge between terminals 50 and 44 to allow electrical current to flow
to ground 34 through lead 39. Thereafter electronic controller 36 transmits
an electrical signal to bleed valve 19 and allows heated pressurized air
to flow into shroud 24 to raise the temperature therein. Thus, through
the temperature sensor 56 and thermostat 40, the pressurized fluid mixture
or air in the supply conduit 12 and the temperature within shroud 24 is
maintained at about 80F. or same other preselected temperature.
As shawn in Figure 1, the pressurized fluid mixture or air
flows through tee 18 to control valve 68. The coil 126 in solenoid
128 is
tm/~,, ,~ -11-
activated through an electrical slgnal transmTtted through lead 142 from
electronic control 36. When actlvated, coll 126 attempts to positlon plunger
124 at the center of the coil 126 ln oppositlon to sprlng 14C. Movement
of plunger 124 moves poppet 134 away from port 112 to seat poppet 136 on
seat 138 and seal the atmospheric chamber 118 from the contrcl chamber llO.
The pressurlzed fluid mixture or air flows through the control valve 68
and Is communicated by conduit 116 to port 189 in container 16.
As stated In the detailed descrtptlon of container 14, the
pressurlzed fluid mlxture or alr enters a flow d7strTbution chamber 186
and Is uniformly d;stributed to the dtsc or plate 180 for communicatlon to
the adsorption material in chamber 176. The pressurized fluid mixture
flows through openings 184 into engagement with the individual particles
of adsorption matertal where at least one component (nitrogen) ts retained
by adsorption. As the pressurized fluid mixture passes through chamber 176
more and more of the element (nitrogen) is removed from the fluid mixture
(alr). However, upon passlng lnto the tntermedlate flow chamber t64 a
small percentage of the element is still in the resulting fluid mixture.
Therefore, tn order to remove the remaining percentage it is necessary to
provide a long flow path where the opportuntty is present for the element
2~ to contact a particle of the adsorptton materlal is increased. Thus, the
intermediate fluid mixture passes from the Intermediate flow distribution
chamber 164 through openings 162 and lnto chamber 178 where any remainlng
element t5 removed before the resultant product fluid (oxygen enriched
breathable fluid) passes tnto flow distribution chamber 196 for dTstribution
to storage container 20 by condutt 216. The pressure of the product fluid
emerging from chamber 196 overcomes sprTng 232 in check valve 224 to move
ball 234 off seat 236 before passing Into storage container 20. The flutd
product (oxygen enriched breathable fluid) passes through a pressure
regulator 238 In condult 22 before betng communicated to a recipient.
As the fluId product flows tn condult 216 from container 16, a
-12-
t~
purge portion is bled off through intermediate conduTt 220 by passing through
restrlctlon 222. Thls purge portlon of the fluid product enters port 200
in container 14 and is uni~ormly distributed through flow chamber 196
to dlsc or plate 190.
During this mode in a cyc1e of operatlons, solenoid 94 is
inoperative and spring 104 moves plunger 90 to seat poppet 98 and prevent
communication through conduit 62 while allowlng communication to the atmosphere
or surroundlng enYironment from control chamber 74 through atmosphere
chamber 84 to bring chamber 176 and 178 into communTcation with the atmosphere.
When the purge portion of the fluld product passes through restriction 222
. an expansion occurs. This expanded purge fluid enters chamber 178 and is
brought Into contact with substantially each particle of adsorption material
to assure complete desorption of the element from chamber 178. The
desorbed element and purge product fluid which pass through the intermediate
chamber 164 is uniformly distributed through openings 160 to chamber 176 and
upon entry Into chamber 176, a further expanslon occurs. Thereafter, this
further expanded purge portion of the product fluid is brought into contact
w7th substantlally every particle of adsorption material in chamber 176.
By the time the purge portion of the fluid product reaches chamber 186,
substantially the entire element is desorbed from the adsorption material
In chamber 176. By the time the purge portion of the fluid product reaches
chamber 186, the substantially entire element is desorbed from the adsorption
material tn chamber 14.
The purge portion of the fluid product and e1ement contai.ned
therein passes through port 188 for distribution to the surrounding environ-
ment through conduit 86 after passing through control valve 64, As the
purge portlon of the fluld product and element flow in conduit 86, a thermal
reactlon is imparted to the supply conduit 12 in the heat exchange section 2ho
to condltlon the pressurized fluid mixture flowlng therein and reduce the
3 amount of input heat requlred from the heater 28.
5'~
Upon exltlng from conduit ~6, the purge portlon of the fluTd
product and element contalned thereTn ts dlrected by shroud 24 to flow
around the separator exchange components before being communicated to the
surrounding environment through openings 242. Thus, the components tn
the separator system are malntalned at substantially the same temperature
durTng a cycle of operatton resardless of the temperature of the sur-
roundlng env~ronment.
Arter a predetermined period, electronlc control 36 deactivates
coTl 126Of soleno1d 128 In control valve 68 and spring 140 seats poppet 134
on the seat 10~ of port 112 to interrupt communication between control
chamber 110 and branch condutt 66. Thereafter, electronlc control 36 supplies
coll 92 of solenoid 94 In control valve 64 with an electrical energy through
lead 106. The electrlcal energy supplied to coil 92 creates a magnetic field
that moves plunger 88 ;n opposition to spring 104 and urges poppet 10G onto
seat 102 to open communfcatton to control chamber 74 with branch conduit 62.
Thereafter,the temperature controlled pressurized fluid flows throughcontrol
valve 64 to container 14 where the flu7d product (oxygen enriched breathable
fluid~ Is produced and communtcated to storage container 20 while a portton
thereof is dlverted through condult 220 to purge the element from the
partlcles In container 16.
In order to evaluate the effecttveness of the insulated shroud 24,
the performance of a separator system 10 without a shroud 24 was operated
under the followlng conditions.
The pressurized fluid mixture or air was sequentially presented
to the beds of materlal in containers 14 and-10 by control valve 64 and 68
at 80F. and 40 psig. The surrounding environment temperature was maintained
at 80F. during the production of a fluld product havlng an oxygen con-
centrat;on at the var.ous flow rates illustrated by curve 244 in Figure 4.
Thereafter, the separator system 10 was presented with pressurized air or
fluld mTxture at 75F. and 40 pslg whtle the surrounding environment
; -14-
i i-
37~
temperature was malntalned at 50F. durlng a second evaluation, and at
30F. durlng a third evaluation to produce proJected output curves 246 and
248, respectively, In Figure 4.
To confirm the results of thls first evaluatlon, a second series
of tests were made at these same temperatures while the pressure of the
fluid mlxture reduced to 25 psig. When the separator system 10 was
operated with the temperature of the pressur;zed fluid mixture or alr and
surrounding environment at 80F. the projected output is illustrated by
curve 250 in Figure 4. Later, when the inlet temperature of the pressurized
fluid mtxture was ~aintained at 75F. and the surrounding envTronment
temperature reduced to 50F. and 30F., projected product output curves 252
and 254 illustrated in Figure 4 were produced.
These tests clearly Tllustrate a need for maTntaining the
temperature of both the pressurized fluid mixture and the beds of adsorption
material at about 80F. in order to optimtze the separation of oxygen from
~- air by thé molecular sieve separator system 10.
Thereafter, further tests were made with the separator system
10 illustrated ln Flsure 1 wlth the shroud 24 of insulated material coverlng
the beds 14 and 16 with the heater member 28 and bleed valve 19 in operation.
20- The temperature of the fluid 0ixture as presented to the beds of material
ln containers 14 and 16 and the surrounding environment was maintained-at
about 80F. and at 40 pslg. The productton of oxygen enriched product
fluid that was achieved is Illustrated by curve ~56 in Figure 5.
Thereafter, the temperature of the surrounding environment was
reduced to a temperature of about -65F, At this temperature, the thermostat
or temperature control 40 and temperature sensor 56 are operational. A
certaln amount of the fluid mixture preheated to 80~, was bled of~ through
solenoid valve 19 to malntaTn the area within the shroud at approximately
80F. However, the production of the oxygen enriched breathable flu~d
that was produced Is illustrated by curve ~58 in F;gure 5.
.
~ -15-
Thereafter, the temperature sensor 56 and thermostat or temperature
control 40 were deactlvated and the temperatura of the surroundlng envlron-
ment ~Ias maintalned at 0F, The productlon of the oxygen enriched product
fluid that was produced Is illustrated by curve 260 in Figure 5.
Thus, it should be apparent from these tests that a most effective
molecular sleve separator is produced by a container where substantially
every partlcle of adsorption materTal is brought Into contact wlth the
fluld mlxture through a varlable area bed of adsorption material and the
. temperature of the system is maintained at about 80F.
Upon evaluating the operation of molecular sieve separators having
a change in area of the bed of adsorption material between the entrance and
exit port of a conta7ner, such as the stepped variation in the area shown
In Figure 2. It is surmised that the optimum bed configuratTon should
have a cross-sectional area that decreases from inlet to outlet, such
as container 270 in Figure 3. The container 270 has a conical shape with
a first flow chamber 272 located between the end cap 274 and the filter
or disc 276. The fllter or disc 276 allows uniform distribution of
the fluid mixture from conduit 80 to the bed of adsorption material retained
in chamber 280. A second disc or filter 282 ls located between end cap 284
and chamber 280 to establish a second flow through chamber 281. For so~e
applicatlons a sprlng 286 may be provided to exert a constant force on
dlsc 282 to maintain a substantlally unTform density In the bed of adsorption
material durlng purge flow condttions. It is antlcipated that the
operatlonal separation of the element from the fluid mixture would be
untform since the conical contalner 270 is designed to compensate for any
decrease in flow of the fluid mixture resulting from adsorption of the
element by the material.
,, "
16-
