FLUID FRACTIONATOR

APPAREIL AMELIORE DE FRACTIONNEMENT DE FLUIDES

English Abstract

Improved apparatus for fractioning fluid mixtures, such
as air, by pressure swing molecular adsorption employs a
rotary distributor valve and an array of adsorber columns.
Columns are, in one embodiment, contained within a product
holding tank or, in another embodiment, attached to a product
tank. Valve sequences to provide a quasi steady-state flow,
allowing optimization of adsorption/desorption cycles, and
eliminating most of the valves, switches and plumbing usually
required.

Claims

IN THE CLAIMS:
1. An apparatus for fractionating a fluid mixture
by pressure swing molecular adsorption having a
pressurizing phase and a desorbing phase which comprises:
a) a first plurality, a second plurality and a
third plurality of adsorber columns, each having a
proximal end and a distal end and each containing a
molecular adsorption medium for fractionation of a
mixture of fluids passed thereinto by separation of said
mixture into a portion which passes through a first one
of the columns in said first plurality, said second
plurality and said third plurality of columns and exits
therefrom during said pressurizing phase as a purified
portion, and a portion which is passed through another
one of said columns in said first plurality, said second
plurality and said third plurality of columns and is
retained by said medium as a retained portion during said
desorbing phase;
b) chamber means surrounding the distal ends of
said columns, means for receiving and storing said
purified portion and a fluid exit port for removal of a
first part of said purified portion from said chamber;
c) a distributor valve assembly comprising:
i. a fluid manifold having fluid channels
for receiving said fluid mixture and purging said
retained portion;
ii. an immobile port plate having a first
plurality, a second plurality and a third plurality of
openings in fluid communication with said columns; said
port plate further having an integral inlet channel for a
substantially continuous flow of fluid;
iii. rotatable distributor means in fluid
communication with said manifold, said means comprising:
(1) a rotor shaft having concentric
and eccentric portions; and,
(2) a rotor shoe operatively coupled
to the rotor shaft and having at least a pair of inlet

ports in fluid communication with and in axial symmetry
about said integral inlet channel, which inlet ports
sequentially pressurize said first plurality of columns
as said rotor shoe rotates said pair of inlet ports over
said first plurality of openings in said port plate; at
least two exhaust ports in axial symmetry about said
integral inlet channel which exhaust ports sequentially
and simultaneously exhaust reflux fluid carrying the
retained portion and emanating from each of said second
plurality of columns as said rotor rotates said exhaust
ports over said second plurality of openings in said port
plate; at least two cross-porting channels, each having
two ports, for connecting at least two columns which are
in said third plurality of columns and which are in
transition between the pressurizing and desorbing phases,
allowing rapid. pressure equalization; and,
d) means for rotating said rotatable
distributor means.
2. An apparatus for fractionating a fluid mixture
as described in claim 1, wherein said openings in said
first, second and third pluralities in said port plate
are non-circular in shape.
3. An apparatus for fractionating a fluid mixture
as described in any of the above claims, wherein said
columns contain means to reduce reflux pressure.
4. An apparatus for fractionating a fluid mixture
as described in claim 3, wherein said means to exhaust
reflux pressure comprises an orifice at the end of each
column opposite said. rotary distributor valve.
5. An apparatus for fractionating a fluid mixture
as described in claim 4, wherein said columns in said
first, second and third pluralities are sealed by a
mechanical sealing means at the end opposite to the
orifice.

6. An apparatus for fractionating a fluid mixture
as described in claim 1, wherein said distributor valve
assembly is contained within a bearing housing, said
housing being at least partially lined with acoustical
attenuating material.
7. An apparatus as in claim 6, wherein said
distributor valve assembly and bearing housing are
contained within a sealed muffler housing, said sealed
muffler housing being at least partially lined with
acoustical attenuating material, and wherein a
compression spring is situated between said rotor shaft
and said rotor shoe.
8. An apparatus for fractionating a fluid mixture
as described in claim 1, wherein said fluid mixture is
air.
9. An apparatus for fractionating a fluid mixture
as in claim 1, wherein said fluid manifold is formed of
more than one layer of material, which layers are stacked
to form fluid channels.
10. An apparatus as in claim 9, wherein said
manifold is die formed and pierced to form fluid
channels.
11. An apparatus as in claim 9, wherein said
manifold is embossed to form fluid channels.
12. An apparatus as in claim 1, wherein said rotor
shaft is seated within said rotor shoe and rotatably
retained therein to form a pressure balanced seal.
13. An improved process for removing a fluid
component of a particular fluid from a stream of a
mixture of fluids or a contaminating component from a
stream of a single fluid through pressure swing

adsorption having a pressurizing phase and a desorbing
phase comprising the steps of:
a) admitting a pressurized fluid mixture into a
rotary valve distributor attached to a first plurality, a
second plurality and a third plurality of adsorber
columns, each of said plurality of columns having
proximal and distal ends;
b) said rotary valve distributor comprising:
i. a fluid manifold having fluid channels
for providing an adsorbing phase and a desorbing phase
and for receiving said fluid mixture before said
adsorbing phase and purging said fluid mixture after said
desorbing phase;
ii. an immobile port plate having a first
plurality and a second plurality of openings in fluid
communication with said first plurality and said second
plurality of adsorber columns, said port plate further
having an integral inlet channel for a substantially
continuous flow of fluid into the first plurality of
adsorber columns;
iii. rotatable distributor means in fluid
communication with said manifold, said means comprising a
rotor shaft having a concentrically shaped portion and an
eccentrically shaped portion, and a rotor shoe
operatively coupled to the rotor shaft and having at
least a pair of inlet ports in fluid communication with
and axial symmetry about said integral inlet channel,
which inlet ports sequentially pressurize said first
plurality of columns as said rotor shoe rotates said pair
of inlet ports over said first plurality of openings in
said port plate; at least two exhaust ports in axial
symmetry with said integral inlet channel which exhaust
ports sequentially and simultaneously exhaust reflux
fluid carrying the retained portion and emanating from
each of said second plurality of columns as said rotor
rotates said exhaust ports over said second plurality of
openings in said port plate; at least two ports for
connecting the columns which are in the third plurality
of columns and which are in transition between the

pressurizing and desorbing phases, allowing rapid
pressure equalization;
c) sequentially distributing said pressurized
fluid mixture, by means of said rotatable distributor
means, into at least one of said first plurality of
columns packed with an adsorbent material selective for
the fluid or contaminant to be removed, where said fluid
or contaminant is retained and desired product fluid is
allowed to pass through to a product tank attached to the
distal end of said columns;
d) simultaneously refluxing, under low
pressure, a portion of product fluid through one or more
of said second plurality of columns, said fluid entering
through an orifice at one end of each said column and
exiting through an opposite end; and
e) simultaneously withdrawing purified product
fluid from said product tank as required.
14. An improved process for fractionating a fluid
mixture as described in claim 13, wherein said columns
have a high length to diameter ratio.
15. An improved process for fractionating a fluid
mixture as described in claim 13, wherein said columns
contain means to reduce reflux pressure.
16. An improved process for fractionating a fluid
mixture as described in claim 13, wherein said
distributor valve assembly is contained within a bearing
housing, said housing being at least partially lined with
acoustical attenuating material.
17. An improved process as in claim 16, wherein
said distributor valve assembly and bearing housing are
contained within a sealed muffler housing, said sealed
muffler housing being at least partially lined with
acoustical attenuating material and wherein said fluid
manifold is formed of more than one layer of material,
which layers are stacked to form fluid channels.

18. An improved process as in claim 17, wherein
said manifold is die formed and pierced to form fluid
channels.
19. An improved process as in claim 17, wherein
said manifold is embossed to form fluid channels.
20. An improved process as in claim 19, wherein
said rotor shaft is seated within said rotor shoe and
rotatably retained therein to form a pressure-balanced
seal.
21. An apparatus for fractionating a fluid mixture
by pressure swing molecular adsorption having a
pressurizing phase and a desorbing phase which comprises:
a) a first plurality, a second plurality and a
third plurality of adsorber columns, each containing
molecular adsorption medium for fractionation of a
mixture of fluids passed thereinto by separation of said
mixture into a portion which passes through one of said
first plurality, said second plurality and said third
plurality of columns and exits therefrom as a purified
portion during said pressurizing phase, and another
portion which is passed through another of said first
plurality, said second plurality and said third plurality
of columns and retained as a retained portion by said
medium during said desorbing phase;
b) chamber means containing said columns, means
for receiving and storing said purified portion and a
fluid exit port for removal of a first part of said
purified portion from said chamber;
c) a distributor valve assembly comprising:
i. a fluid manifold for receiving said
fluid mixture and purging said retained portion;
ii. an immobile port plate having a first,
second and third plurality of openings in fluid
communication with said columns; said port plate further
having an integral inlet channel for a substantially
continuous flow of fluid; and

iii. rotatable distributor means in fluid
communication with said manifold, said means comprising a
rotor and rotor shoe having an arcuate distribution port
which sequentially pressurizes said first plurality of
columns as said rotor shoe rotates said distribution port
over said first plurality of openings in said port plate;
an arcuate exhaust port which sequentially and
simultaneously exhausts reflux fluid carrying the
retained portion and emanating from each of said second
plurality of columns as said rotor rotates said exhaust
port over said second plurality of openings in said port
plate; a cross-porting channel with two ports, each
situated between the arcuate distribution and exhaust
ports, for connecting two columns in said third plurality
of columns, which columns are in transition between the
pressurizing and desorbing phases, allowing rapid
pressure equalization; said rotor shoe further having an
integral exhaust channel for a substantially continuous
exhaust of fluid carrying the retained portion; and
d) means for rotating said rotatable
distribution means.
22. An apparatus for fractionating a fluid mixture
as described in claim 21, wherein each of said first
plurality, said second plurality and said third plurality
of adsorber columns contains at least two columns.
23. An apparatus for fractionating a fluid mixture
as described in claim 21, wherein said columns have a
high length to diameter ratio.
24. An apparatus for fractionating a fluid mixture
as described in claim 21, wherein said columns contain
means to reduce reflux pressure.
25. An apparatus for fractionating a fluid mixture
as described in claim 24, wherein said means to reduce
reflux pressure comprises an orifice at the end of each

column opposite said connection to said manifold in said
distributor valve assembly.
26. An apparatus for fractionating a fluid mixture
as described in claim 21, wherein said columns contain
spring means to keep the medium compacted and wherein
said fluid mixture is air.
27. An apparatus for fractionating a fluid mixture
as described in claim 21, wherein said chamber means is
closed at one end and sealed by said distributor valve
assembly at the other end.
28. An apparatus for fractionating a fluid mixture
as described in claim 21, wherein said chamber means has
said fluid exit port for removal of said purified portion
located in said fluid manifold.
29. An improved process for removing a fluid
component of a particular fluid from a stream of a
mixture of fluids or a contaminating component from a
stream of a single fluid through pressure swing
adsorption having a pressurizing phase and a desorbing
phase comprising the steps of:
a) admitting a pressurized fluid mixture into a
rotary valve distributor;
b) said rotary valve distributor comprising:
i. a fluid manifold for receiving said
fluid mixture and purging said contaminating component;
ii. an immobile port plate having a first
plurality, a second plurality and a third plurality of
openings in fluid communication with a first plurality, a
second plurality and a third plurality of columns; said
port plate further having an integral inlet channel for a
substantially continuous flow of fluid; and
iii. rotatable distributor means in fluid
communication with said manifold, said rotatable
distributor means comprising a rotor and rotor shoe
having an arcuate distribution port which sequentially

pressurizes said first plurality of columns as said rotor
shoe rotates said distributor port over said first
plurality of openings in said port plate; an arcuate
exhaust port which sequentially and simultaneously
exhausts fluid carrying the contaminating component and
emanating from each of said second plurality of columns
as said rotor rotates said exhaust port over said second
plurality of openings in said port plate; a cross-porting
channel with two ports, each situated between the arcuate
distribution and exhaust ports, for connecting two
columns in said third plurality of columns, which two (2)
columns are in. transition between the pressurizing and
desorbing phases, allowing rapid pressure equalization;
said rotor shoe further having an integral exhaust
channel for a substantially continuous exhaust of fluid
carrying the contaminating component; and
c) sequentially distributing said pressurized
fluid mixture, by means of said rotary valve distributor,
into at least one of said first plurality of columns
packed with an adsorbent material selective for the fluid
or contaminant to be removed, where said fluid or
contaminant is retained and desired product fluid is
allowed to pass through; and
d) simultaneously refluxing, under low
pressure, a portion of product fluid through one or more
of said second plurality of columns, said fluid entering
through an orifice at one end of each said column and
exiting through an apposite end and into the atmosphere;
and
e) simultaneously withdrawing purified product
fluid as required.
30. An improved process for removing a fluid
component of a particular fluid from a stream of a
mixture of fluids or a contaminating component from a
stream of a single fluid as recited in claim 29, wherein
said adsorbent material in step c is a zeolite.

31. An improved process for removing a fluid
component of a particular fluid from a stream of a
mixture of fluids or a contaminating component from a
stream of a single fluid as recited in claim 30, wherein
each of said first plurality, second plurality and third
plurality of columns contains at least two columns.
32. An apparatus comprising:
first means for providing air under pressure, a
column having a cylindrical configuration with a
length-to-diameter ratio of at least six to one (6:1),
second means including a rotary distributor
valve for directing the air under pressure into the
column,
an adsorption medium disposed in the column,
without any member in the column to compress or retain
the adsorption medium in the column, for adsorbing
components of the air under pressure other than oxygen
and for passing the oxygen in the air through the
adsorption medium, and
third means for collecting the oxygen passed
through the adsorption medium in the column,
the column having first and second opposite
ends, along its length, and
a filter medium disposed in the column at the
first and second opposite ends of the column to avoid
loss of the adsorption medium from the column during the
adsorption in the column of the components other than the
oxygen and the passage of the oxygen through the column.
33. An apparatus as set forth in claim 32, wherein
the air contains gases other than oxygen and
wherein
the second means is operative to direct the air
into the column at first particular times, and further
including
fourth means for passing gases in the column,
after the passage of the oxygen through the adsorption

medium, to the atmosphere at second particular times
different from the first particular times, and
fifth means for selectively releasing from the
absorption medium the oxygen collected in the adsorption
medium, and wherein
the adsorption medium and the filter medium are
the only means. in the column.
34. The apparatus as set forth in claim 32, further
including
fourth means for selectively releasing from the
adsorption medium the oxygen collected in the adsorption
medium,
the adsorption medium and the filter medium
being the only elements in the column.
35. An apparatus comprising:
a plurality of columns, more than two (2)
disposed in a closed loop,
first means for providing a fluid under
pressure, the fluid having a first component and having
components other than the first component,
second means operatively coupled to the first
means and the columns in the plurality and including a
rotary distributor valve for directing the fluid under
pressure into first progressive ones, more than one (1),
of the columns in the plurality and for providing for the
flow of the fluid in the columns from second progressive
ones, more than one (1), of the columns in the plurality,
third means disposed in the columns for passing
the first component of the fluid and for adsorbing other
components of the fluid,
fourth means for collecting the first component
from the first progressive ones of the columns in the
plurality, and
fifth means for exhausting to the atmosphere
the fluid from the second progressive ones of the columns
in the plurality.

36. The apparatus as set forth in claim 35,
wherein
the second means is operative to equalize the
pressure of the fluid in third progressive ones, more
than one (1), of the columns in the plurality, the third
progressive ones of the columns in the plurality being
between the first and second progressive ones of the
columns in the plurality.
37. The apparatus as set forth in claim 35, wherein
the columns in the plurality are cylindrical,
the second means include first channels
symmetrically disposed relative to each other for
directing the fluid into the first progressive ones of
the columns in the plurality and also including second
channels symmetrically disposed relative to each other
for providing for the flow of the fluid, other than the
first component, from the second progressive ones of the
columns in the plurality, the first progressive ones of
the columns being symmetrically disposed relative to each
other in the closed loop, the second progressive ones of
the columns in the plurality being symmetrically disposed
relative to each other in the closed loop, the second
means including third channels symmetrically disposed
relative to each other to equalize the pressure of the
fluid in third progressive ones of the columns in the
plurality, the third progressive ones of the columns in
the plurality being symmetrically disposed relative to
each other in the closed loop and being disposed between
the first and second ones of the progressive columns in
the plurality.
38. The apparatus as set forth in claim 35, further
including
sixth means for providing a filter medium in
each of the columns to avoid loss of the third means from
the columns during the passage of the first component of
the fluid through the column and the adsorption of the
other components of the fluid in the column, the third

and sixth means constituting the only means in each of
the columns in the first, second and third pluralities.
39. An apparatus comprising:
first means for providing a fluid under
pressure, the fluid having a first component and other
components,
a plurality of columns, more than two (2),
disposed in a configuration defining a closed loop,
second means including a rotary distributor
valve having first channels symmetrically disposed
relative to each other for directing the fluid under
pressure into first progressive ones of the columns in
the plurality and having second channels symmetrically
disposed relative to each other for directing the fluid
from second progressive ones of the columns in the
plurality, the first progressive ones of the columns in
the plurality being symmetrically disposed relative to
each other in the closed loop and the second progressive
ones of the columns in the plurality being symmetrically
disposed relative to each other in the closed loop,
third means disposed in the columns in the
plurality for adsorbing the other components in the fluid
and for passing the first component in the fluid, and
fourth means for collecting the first component passing
through the first progressive ones of the columns in the
plurality.
40. The apparatus as set forth in claim 39, wherein
the second means is annular and the first
channels in the second means are symmetrically disposed
relative to each other in the diametrical direction and
the second channels in the second means are displaced
from the first channels and are symmetrically disposed
relative to each other in the diametrical direction, the
second means including third channels symmetrically
disposed relative to each other for equalizing the
pressure of the fluid in third progressive ones of the
columns in the plurality, the third progressive ones of

the columns in the plurality being symmetrically disposed
relative to each other in the closed loop, and the third
channels in the second means being displaced from the
first and second channels and being disposed between the
first and second channels.
41. The apparatus as set forth in claim 40, wherein
the second channels in the second means are
further displaced in the diametrical direction than the
third channels in the second means.

42. In combination,
a plurality of columns disposed in a closed
loop, each of the columns having a length-to-width ratio of
at least six to one (6:1),
means for providing a fluid under pressure,
the fluid having a first component and having components
other than the first component,
means operatively coupled to the fluid
pressure means and the columns in the plurality for directing
the fluid under pressure into first progressive ones of the
columns in the plurality and for providing for the flow of
the fluid in the columns from second progressive ones of the
columns in the plurality at the same time as the direction of
the fluid under pressure into the first progressive ones of
the columns in the plurality,
the fluid directing means being also operative
to equalize the pressure of the fluid in third progressive
ones of the columns in the plurality between the first and
second progressive ones of the columns in the plurality at
the same time as the directing of the fluid under pressure
into the first progressive ones of the columns in the
plurality,
means disposed in the columns for passing the
first component of the fluid and for adsorbing other
components of the fluid,
means for collecting the first component from
the first progressive ones of the columns in the plurality,
and
means for exhausting to the atmosphere the
fluid from the second progressive ones of the columns in the
plurality.
43. In a combination as set forth in claim 42,
the fluid directing means having a first
plurality of channels symmetrically disposed relative to each
other for directing the fluid under pressure into the first
progressive ones of the columns in the plurality, a second
plurality of channels symmetrically disposed relative to each
other for providing for the flow of the fluid from the second

progressive ones of the columns in the plurality at the same
time as the directing of the fluid under pressure into the
first progressive ones of the columns in the plurality and a
third plurality of channels symmetrically disposed relative
to each other for equalizing the pressure of the fluid in the
third progressive ones of the columns in the plurality at the
same time as the directing of the fluid under pressure into
the first progressive ones of the columns in the plurality.
44. In a combination as set forth in claim 42,
the columns in the plurality being cylindrical
and being concentrically disposed about a common axial
position,
the fluid-directing means including first
channels symmetrically disposed relative to each other about
the common axial position for directing the fluid into the
first progressive ones of the columns in the plurality and
also including second channels symmetrically disposed
relative to each other about the common axial position for
providing for the flow of the fluid from the second
progressive ones of the columns in the plurality at the same
time as the directing of the fluid under pressure into the
first progressive ones of the columns in the plurality and
also including third channels symmetrically disposed relative
to each other about the common axial position for equalizing
the pressure of the fluid in the third progressive ones of
the channels in the plurality at the same time as the
directing of the fluid under pressure into the first
progressive ones of the columns in the plurality, the first
progressive ones of the columns in the plurality being
symmetrically disposed relative to each other in the closed
loop, the second progressive ones of the columns in the
plurality being symmetrically disposed relative to each other
in the closed loop, the third progressive ones of the columns
in the plurality being symmetrically disposed relative to
each other in the closed loop.

45. In a combination as set forth in claim 44,
a housing for at least partially holding the
columns in the plurality, and
means disposed within the housing for
attenuating any noise generated by the fluid directing means
in directing the fluid under pressure into the first
progressive ones of the columns in the plurality.
46. In a combination as set forth in claim 42,
means for providing a filter medium at the
output end of each of the columns in the plurality to avoid
loss of the fluid passing and adsorbing means from such column
during the passage of the first component of the fluid through
such column and the adsorption of the other components of the
fluid in such column.
47. In a combination as set forth in claim 46,
the fluid passing and adsorbing means and the
filter medium means constituting the only means in each of the
columns in the plurality.
48. In combination,
means for providing a fluid under pressure, the
fluid having a first component and other components,
a plurality of columns, more than two (2),
disposed in a configuration defining a closed loop,
means including a plurality of channels, first
channels in the plurality being symmetrically disposed
relative to each other for directing the fluid under pressure
into first progressive ones of the columns in the plurality
and second channels in the plurality being symmetrically
disposed relative to each other for directing the fluid from
second progressive ones of the channels in the plurality at
the same time as the direction of the fluid under pressure in
the first progressive ones of the columns in the plurality,
the first progressive ones of the columns in the plurality
being symmetrically disposed in the closed loop and the second
progressive ones of the columns being symmetrically disposed
in the closed loop,

means disposed in the columns in the plurality
for adsorbing the other components in the fluid and for
passing the first component in the fluid, and
means for collecting the first component
passing through the first progressive ones of the columns in
the plurality.
49. In a combination as set forth in claim 48,
the fluid directing means being annular and the
first channels in the plurality being symmetrically disposed
relative to each other in a diametrical direction and the
second channels in the plurality being displaced from the
first channels and being symmetrically disposed relative to
each other in the diametrical direction.
50. In a combination as set forth in claim 48,
third channels in the plurality symmetrically
disposed relative to each other in the diametrical direction
for equalizing the pressure of the fluid in third progressive
ones of the columns in the plurality at the same time as the
directing of the fluid under pressure into the first
progressive ones of the columns in the plurality, the third
progressive ones of the columns in the plurality being
symmetrically disposed relative to each other in the closed
loop.
51. In a combination as set forth in claim 50,
the fluid directing means is annular and the
first channels in the fluid directing means are symmetrically
disposed relative to each other in the diametrical direction
and the second channels in the fluid directing means are
displaced from the first channels and are symmetrically
disposed relative to each other in the diametrical direction
and the third channels in the fluid directing means are
displaced from the first and second channels and are between
the first and second channels and are diametrically disposed
relative to each other
a housing for at least partially holding the
columns in the plurality, and

means disposed within the housing for
attenuating any noise generated by the fluid directing means
in directing the fluid under pressure into the columns in the
plurality.
52. In a combination as set forth in claim 51
wherein the second channels in the fluid directing means are
further displaced in the diametrical direction than the first
channels in the fluid directing means.
53. In a combination as set forth in claim 51
wherein the columns in the plurality have a length-to-diameter
ratio of at least six to one (6:1).
54. In a combination as set forth in claim 50
wherein the columns in the plurality have a length-to-diameter
ratio of at least six to one (6:1) and the third progressive
ones of the columns in the plurality are symmetrically
disposed relative to each other between the first and second
progressive ones of the columns in the plurality.
55. In combination,
a plurality of columns,
means for providing a fluid under pressure into
first progressive ones of the columns in the plurality, the
fluid having a first component and other components,
means disposed in the columns in the plurality
for adsorbing the other components in the fluid in the columns
in the plurality and for passing the first component in the
fluid in the columns,
means for providing for the passage of the

fluid from second progressive ones of the columns in the



plurality at the same time as the provision of the fluid under



pressure into the first progressive ones of the columns in the


plurality,

means for collecting the first component of the

fluid in the first progressive ones of the columns in the

plurality,

a housing covering the fluid providing and
fluid passage means and at least partially covering the
columns in the plurality, and
means disposed in the housing for attenuating
any noise generated by the fluid providing means and the fluid
passage means.
56. In a combination as set forth in claim 55,
the housing being constructed from a material
having characteristics of muffling the noise.
57. In a combination as set forth in claim 55,
the fluid providing means and the fluid passage
means being included in a rotary distributor valve and a
manifold,
the housing being disposed on the manifold, and
the attenuating means including means disposed
between the manifold and the housing for attenuating any noise
generated by the fluid passage means, and
the manifold including means the means disposed
between the manifold and the housing for holding in fixed
position within the housing.
58. In a combination as set forth in claim 57,
the housing being constructed from a material
having characteristics for muffling the noise and having an
inner wall, and
the attenuating means including means disposed
within the housing against the inner wall of the housing for
further attenuating any noise generated by the fluid passage
means.
59. In combination,
a plurality of columns, more than two (2),
disposed in an annular configuration,
means for providing a fluid under pressure, the
fluid having a first component and other components,
means disposed in the columns in the plurality
for adsorbing the other components in the fluid in the columns

in the plurality and for passing the first component in the
fluid in such columns,
a manifold,
a rotary valve,
a distributor for co-operating with the rotary
valve and the manifold for introducing the fluid under
pressure into first progressive ones of the columns in the
plurality to obtain the passage of the first component of the
fluid through such columns and the adsorption of the other
components of the fluid in such columns and for providing for
the passage of the fluid from second progressive ones of the
columns in the plurality at the same time as the introducing
of the fluid under pressure into the first progressive ones
of the columns in the plurality, and
a housing disposed on the manifold for
attenuating any noise generated by the rotary valve and the
distributor, the housing being constructed from a material
having characteristics of muffling the noise.
60. In a combination as set forth in claim 59,
means disposed within the housing and
conforming topographically to the contour of the housing and
constructed from a material having characteristics of
attenuating any noise generated by the rotary valve and the
distributor.
61. In a combination as set forth in claim 59,
means disposed between the housing and the
manifold in a direction transverse to the manifold and made
from a material having characteristics of attenuating any
noise generated by the rotary valve and the distributor, and
means included in the manifold for retaining
the attenuating means in fixed position in the housing.
62. In a combination as set forth in claim 61,
means disposed within the housing and
conforming topographically to the contour of the housing and
constructed from a material having characteristics of

attenuating any noise generated by the rotary valve and the
distributor.
63. In a combination as set forth in claim 62,
means disposed in the walls of the housing for
passing from the housing any noise not dissipated by the
attenuating means and the topographically conforming means.
64. In a combination as set forth in claim 62,
the rotary valve including first channels
symmetrically disposed relative to each other for providing
for the introduction of the fluid under pressure into the
first progressive ones of the columns in the plurality and
including second channels symmetrically disposed relative to
each other for providing for the passage of the fluid from the
second progressive ones of the ones of the columns in the
plurality.
65. In a combination as set forth in claim 61,
the columns in the plurality being cylindrical,
each of the columns having a length-to-diameter ratio of at
least six to one (6:1), the adsorbing means being the only
means in the columns in the plurality.
66. In combination,
a plurality of columns,
first means for providing a fluid under
pressure, the fluid having a first component and other
components,
second means disposed in the columns in the
plurality for adsorbing the other components in the fluid in
the columns in the plurality and for passing the first
components in the plurality,
third means for introducing the fluid under
pressure into first progressive ones of the columns in the
plurality to obtain the passage of the first component of the
fluid through such columns and the adsorption of the other
components of the fluid in such columns and for providing for

the passage of the fluid from second progressive ones of the
columns in the plurality,
fourth means disposed at one end of the columns
for providing for the passage of the first component of the
fluid in the first progressive ones of the columns in the
plurality, and
a product tank extending from a position near
the fourth means and enveloping the columns in the plurality
at the ends near the fourth means for storing the first
component of the fluid passing through the fourth means.
67. In a combination as set forth in claim 66,
the third means including a manifold extending
across the columns in the plurality at the end of the columns
opposite the fourth means and including a rotor disposed in
co-operative relationship with the manifold at a position
further removed from the manifold than the fourth means for
sequentially and cyclically selecting the first and second
progressive ones of the columns in the plurality and the
product tank enveloping the columns in the plurality at a
position along the columns between the fourth means and the
manifold.
68. In a combination as set forth in claim 67,
a housing disposed on the manifold and
extending from the manifold in a direction opposite the
disposition of the product tank, and
fifth means disposed in the housing for
attenuating any noise created by the flow of the fluid from
the second progressive ones of the columns in the plurality.
69. In a combination as set forth in claim 67,
the rotor including first channels
symmetrically disposed relative to each other for implementing
the introduction of the fluid under pressure into the first
progressive ones of the columns in the plurality and including
second channels symmetrically disposed relative to each other
for implementing the passage of the fluid from the second
progressive ones of the columns in the plurality.

70. In a combination as recited in claim 69,
the rotor including third channels
symmetrically disposed relative to each other for equalizing
the pressures in third progressive ones of the columns in the
plurality, the third progressive columns in the plurality
being disposed between the first and second progressive
columns in the plurality,
a housing disposed on the manifold and
extending from the manifold in a direction opposite the
disposition of the product tank, and
fifth means disposed in the housing for
attenuating any noise created by the flow of the fluid into
the first progressive ones of the columns in the plurality and
by the flow of the fluid from the second progressive ones of
the columns in the plurality.
71. In a combination as set forth in claim 66,
the third means being operative to equalize the
pressures in third progressive ones of the columns in the
plurality, the third progressive ones of the columns in the
plurality being disposed between the first and second
progressive columns in the plurality.
72. In a combination as set forth in claim 66,
the columns being cylindrical and the columns
have a length-to-diameter ratio of at least six to one (6:1).
73. In combination,
a plurality, more than two (2), of columns,
means for producing a fluid under pressure, the
fluid including a first component and other components,
means disposed in the columns in the plurality
for adsorbing the other components and for passing the first
component,
a rotor,
means for driving the rotor,
a rotor shoe movable with the rotor, there
being channels in the rotor for passing the fluid under
pressure into first progressive ones of the columns in the

plurality to obtain the adsorption of the other components in
such columns and the passage of the first component through
such columns and for passing the other components from second
progressive ones of the columns in the plurality at the same
time as the passage of the fluid under pressure into the first
progressive ones of the columns in the plurality,
means disposed between the rotor and the rotor
shoe for balancing the rotor and the rotor shoe, and
means for collecting and storing the first
component of the fluid passing through the first progressive
ones of the columns in the plurality.
74. In a combination as set forth in claim 73,
the columns being disposed in an annular
configuration,
the rotor being disposed within the rotor shoe,
means disposed between the rotor and the rotor
shoe for sealing the rotor and the rotor shoe, and
the balancing means being disposed between the
rotor and the rotor shoe to assist in the sealing of the rotor
and the rotor shoe and the balancing of the rotor and the
rotor shoe.
75. In a combination as set forth in claim 74,
the balancing means including a compression
spring between the rotor and the rotor shoe.
76. In a combination as set forth in claim 74,
the rotor shoe including first channels
symmetrically disposed relative to each other for providing
for the introduction of the fluid under pressure into the
first ones of the progressive columns in the plurality and
including second channels symmetrically disposed relative to
each other for providing for the passage of the fluid from the
second progressive ones of the columns in the plurality.
77. In combination,
a plurality of columns, more than two (2),
disposed in an annular relationship,

means for providing a fluid under pressure, the
fluid having a first component and other components,
means disposed in the columns in the plurality
for adsorbing the other components in the plurality and for
passing the first component of the fluid,
a rotor,
means for driving the rotor,
a rotor shoe disposed in enveloping and
concentric relationship to the rotor for movement with the
rotor, the rotor shoe having first channel means for directing
the fluid under pressure into first progressive ones of the
columns in the plurality on a cyclic basis and second channel
means for directing the fluid from second progressive columns
in the plurality on a cyclic basis at the same time as the
passage of the fluid under pressure into the first progressive
ones of the columns in the plurality,
means for collecting and storing the first
component of the fluid passing through the first progressive
ones of the columns in the plurality,
means disposed between the rotor and the rotor
shoe for sealing the rotor and the rotor shoe relative to each
other, and
means disposed between the rotor and the rotor
shoe for pressure balancing the rotor and the rotor shoe.
78. In a combination as set forth in claim 77,
the rotor shoe enveloping the rotor in the
radial direction and having a portion extending radially
inwardly in axially spaced relation to the rotor and the
balancing means being disposed between the radially extending
portion of the rotor shoe and the rotor for pressure balancing
the rotor shoe.
79. In a combination as set forth in claim 78,
the sealing means including an O-ring, and
the balancing means including a spring.
80. In a combination as set forth in claim 79,

the rotor shoe including a third channel
disposed between the first and second channels for equalizing
the pressure of the fluid in third progressive ones of the
columns in the plurality on a cyclic basis at the same time
as the passage of the fluid under pressure into the first
progressive ones of the columns in the plurality.
81. In a combination as set forth in claim 77,
the rotor shoe including at least a pair of
first channels symmetrically disposed relative to each other
for directing fluid into the first progressive ones of the
columns in the plurality and including at least a pair of
second channels symmetrically disposed relative to each other
for directing the fluid from the second progressive columns
in the plurality and including at least a pair of third
channels symmetrically disposed relative to each other for
equalizing the pressure of the fluid in third progressive ones
of the columns in the plurality.
82. In a combination as set forth in claim 77,
the columns in the plurality having a length-to-diameter
ratio of at least six to one (6:1).
83. In a combination as set forth in claim 77,
a manifold disposed in co-operative
relationship with the rotor shoe for implementing the
direction of the fluid under pressure into the first
progressive ones of the columns in the plurality and for
implementing the flow of the fluid from the second progressive
ones of the columns in the plurality,
a housing disposed on the manifold and
extending in a direction opposite the collecting and storing
means, and
means disposed in the housing for attenuating
any noise generated as a result of the rotation of the rotor
and the rotor shoe.
84. In combination,
means for providing a fluid under pressure,

a plurality of columns, more than two (2),
disposed in a closed loop,
valve means for providing an introduction of
the fluid under pressure into first progressive ones of the
columns in the plurality on the cyclic basis and for providing
for the flow of the fluid from second progressive ones of the
columns in the plurality on the cyclic basis at the same time
as the introduction of the fluid under pressure into the first
progressive ones of the columns in the plurality,
the valve means being operative to provide for
the introduction of the fluid under pressure into the first
progressive ones of the columns in the plurality on a balanced
basis and to provide for the flow of the fluid from the second
progressive ones of the columns in the plurality on a balanced
basis,
the valve means being rotatable, and
means for balancing the valve means during the
rotation of the valve means.
85. In a combination as set forth in claim 84,
the valve means being operative on a balanced
basis to equalize the pressure of the fluid in third
progressive ones of the columns in the plurality at the same
time as the introduction of the fluid under pressure into the
first progressive ones of the columns in the plurality.
86. In a combination as set forth in claim 85,
a housing for holding the valve means and the
balancing means and for at least partially enveloping the
columns in the plurality,
the housing being made from a material for
attenuating any noise generated by the operation of the valve
means, and
means disposed within the housing for
attenuating any noise generated by the operation of the valve
means.
87. In a combination as set forth in claim 86,

the fluid under pressure having a plurality of
different components, and
means disposed within the first progressive
ones of the columns in the plurality for passing through such
columns a first particular one of the components in the fluid.
88. In a combination as set forth in claim 84,
a housing for holding the valve means and the
balancing means and for at least partially enveloping the
columns in the plurality, and
means disposed within the housing for
attenuating any noise generated by the operation of the valve
means.
89. In a combination as set forth in claim 84,
the fluid under pressure having a plurality of
different components,
means disposed within the first progressive
ones of the columns in the plurality for passing through such
columns a first particular one of the components in the fluid.

Description

WO 93/1C~7t3b PCT/US92/01510
~l~
-1-
IMPROVED FLUID FRACTIONATOR
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an improved apparatus and
method for purifying a fluid product by removing certain
components of a fluid mixture or contaminants from a source
of a single fluid. Since this invention is effective in
separation of. gases and liquids, depending on
circumstances, the term fluid will be used as much as
possible. It is understood that the term includes gases and
liquids. Although focus is directed to the medical use as
a respiratory support in the present embodiment, this
invention is also useful in other situations where zeolites
and sieve materials are employed, for example oil refinery
procedures.
2. Description of the Related Art
The use of selectively adsorbent molecular sieve
materials having uniform pore sizes in separation of fluid
components has been in practice since about 1948, with the
first industrial research efforts occurring at 'Union
Carbide Corporation. Based on the first experimental
observations of the adsorption of gases on naturally
occurring zeolites and the behavior of the latter as
molecular sieves by Barter in 1945 (J. Soc. Chem. Ind.,
64:130), Milton and coworkers at Union Carbide synthesized
the first industrial zeolite molecular sieves in 1948 (R. M.
as

V4'O 93/ 1 G78G pCT1 US92/O 1 S 1 U
,'.
~,lf.~i.~:~ ~-
-2-
Milton, Molecular Sieves, Soc. Chem. Ind., London, 1968, p.
199), and they were test marketed in 1954.
Most separations of fluid mixtures by adsorption
require regeneration of the adsorbent after saturation with
the adsorbate. Since most separations are performed on
fixed-bed columns, complex mechanisms involving intricate
networks of interconnected and interoperating valves and
switches have been devised to implement adsorption and
desorption cycles in order to facilitate regeneration.
Costly and elaborate equipment like that described
above is suitable for large scale commercial operations
where the equipment is constantly monitored by competent
technicians. However, in dealing with the problem of
supplying relatively small quantities of oxygen to
patients, especially at home, size, ease of operation and,
even more importantly, reliability are the primary
concerns.
The use of synthetic molecular sieves in a two-bed,
pressure swing adsorber for separation of oxygen from air
for medical and industrial applications became commercially
practical in the early 1970's and many manufacturers now
build such equipment.
The components in a typical two column system
currently available are:
Air compressor
Heat exchanger
Air receiver or surge tank
Two molecular sieve chambers
Two pressure dropping orifices
Product tank (oxygen receiver)
Four or five two-way solenoid operated directional
flow control valves (or, alternatively, one 4-way
valve and one 2-way valve)
Electrical or electronic sequencing timer control for
the valves

fVn y3/ 1 (,7gG fCT/US92/01 S 10
-3-
Pressure reducing regulator for oxygen product.flow
Intake and exhaust silencers
Intake and product filters
Adjustable flow control valve for oxygen product floc~~
Connecting tubing and fittings to conduct fluid flows
into and out of components
The above list of components clearly indicates the
complexity of a typical medical oxygen concentrator (or
respiratory support system), requiring a network of
l0 interconnected parts acting in concert. This complexity
can give rise to the prospect of decreased reliability, and
the chance that same component will malfunction, or a
connection leak will develop,. rendering the entire
apparatus incapable of performing its life-support
function.
The compressor discharge profile in a two column
system, when plotted against time manifests a "sawtooth"
pattern which is responsible for shortening compressor
valve and bearing life, requiring an air receiver or surge
tank to limit such fluctuation. This cyclic flow in the two
column adsorber also produces large pressure variations in
product gas flow, requiring the use of a pressure reducing
regulator in the dispensing conduit. The abrupt, large
pressure changes also require extensive silencing.
Furthermore, to provide an ambulatory patient with
acceptable mobility and quality of life, a supplementary
oxygen supply system must be reliable, economical, compact,
portable and light in weight. The instant invention
provides a system which addresses all these parameters.

iVn 93/ 1 G78G I'Cl~/ US92/O 151 (1
-4-
SUMMARY OF THE INVENTION
This invention encompasses improved apparatuses for
fractionating a fluid mixture by pressure swing molecular
adsorption. These apparatuses contain a plurality of
adsorber columns and a chamber functioning as a purified
product holding tank.
The heart of the apparatuses are unique, rotary
distributor valve assemblies for sequentially pressurizing
and exhausting each column. This allows pressurization of
l0 one of the columns while simultaneously purging the
adsorbent medium in another of such columns. -
This invention further encompasses improved processes
for removing fluid components by selective adsorption of
particular fluids from a stream of a mixture of fluids or
a contaminating fluid component~from a stream of a single
f luid .
An incoming stream of a pressurized fluid mixture is
sequentially distributed by means of rotating members of
the rotary distributor valves of the alternative
embodiments disclosed herein into a plurality of columns
packed with an adsorbent which is selecti~ie for the fluid
or the contaminant fluids to be removed. The contaminants
are retained by the adsorbent and the desired product fluid
is allowed to pass through. By simultaneously refluxing
product fluid-under low pressure, through columns other
than columns being pressurized, the contaminant is desorbed
and exits the system.
Novel, smaller, smoother in operation, simpler and
more reliable apparatuses for providing supplementary
oxygen to patients are presented below as exemplary
embodiments of the instant invention. Improved methods of
fractionating fluid mixtures, which arise out of judicious
use of the described apparatuses, are also presented.

1f() 93/ i G786 'w ~ ~ ~ U ~ ~ PCTI US92/0l 510
-5-
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 depicts schematically a typical two-column
adsorbent fractionating prior art system commercially
available.
Figure 2 is a schematic representation of one
embodiment of the entire fluid fractionator respiratory
support system of the instant invention.
Figure 3 is a side elevation view of the apparatus
which is the subject of Figure 2.
Figure 4 is a view taken on line 4-4 of Figure 3.
Figure 5 is an enlarged sectional view taken on line
5-5 of Figure 4.
Figure 6 is a sectional view taken on line 6-6 of
Figure 5.
Figure 7 is a top plan view, partially cut away, of
the rotor shoe, of the embodiment depicted in Figure 2;
Figure 8 is a sectional view taken on line 8-8 of
Figure 7;
Figure 9 is a top plan view of the port plate of the
embodiment depicted in Figure 2;
Figure 10 is a sectional view taken on line l0-l0 of
Figure 9;
Figure 11 is a side elevational view of an alternative
configuration of the unit;
Figure 12 is a sectional view taken on line 12-12 of
Figure 11;
Figure 13 is an enlarged sectional view taken on line
13-13 of Figure 12;
Figure 14 is a sectional view taken on line 14-14 of
Figure 13;
Figure 15 is an underside view of the rotor shoe as
taken on line 15-15 of Figure 13;
Figure 16 is a sectional view taken on line 16-16 of
Figure 15; and

tV0 93/ 16786 1'CT/ US92/01 ~ t 0
Figure 17 is an enlarged sectional view taken on line
17-17 of Figure 12.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Figure 1 depicts schematically a typical small two
s column oxygen concentrator commercially available for
patient use. It can readily be seen from the schematic
diagram that a typical medical oxygen concentrator is a
complex machine, with a multitude of interconnected and
interacting parts. Attendant with this manifold complexity
is the prospect of decreased reliability, or the increased
chance that some component will fail, rendering the entire
apparatus incapable of performing its life-supporting
function.
One embodiment of this invention, with its unique
design which requires far fewer parts, will be described by
following a volume of mixed fluids (air in this case) as it
moves through the fractionation procedure. In Figure 2,
ambient air is drawn in through a pair of filters, one dust
1 and one high efficiency particle arrestor (HEPA). 2
connected in series, by a compressor 3. The air is
compressed and forced within a conduit '4 into a heat
exchanger 5. (It should be noted that the filters shown in
both Figure 1 and 2 could follow,'rather than precede, the
compressor). The heat exchanger removes most of the heat
of compression before the air is fed into the inlet port 6
of the fluid fractionator. The cooling air in the
exchanger is provided by a fan mounted on the compressor
shaft, thereby, obviating the requirement of an additional
motor and energy source. After most of the nitrogen is
removed by the adsorber columns of the fractionator, an
oxygen-rich fraction is tapped off through an outlet port
7 to the dispensing conduit, while the desorbed nitrogen is
purged by the balance of the oxygen-rich product flow and
leaves through an exhaust port 8.

1fn 93/ I G7HG ~ ~ ~ ;~ PCT/ US92/01510
r
-7-
The fluid fractionator, in Figure 3, comprises a
product holding tank 9 containing a cluster or array of
adsorber columns within its housing, a rotary valve
distributor l0 and a gear motor 11.
Figure 4, a view taken on line 4-4 of Figure 3, shows
the arrangement of an array of columns 22 within the
holding tank relative to the inlet 6, outlet 7 and exhaust
8 ports of the rotary distributor valve assembly, which is
affixed to the holding tank by means of a clamp-band 12.
l0 Twelve columns are shown in this case but there could be
any number of two or more.
The rotary distributor valve depicted in Figure 5,
which is an enlarged sectional view taken on line 5-5 of
Figure 4, comprises a ported and channelled two-piece
manifold 14 and a rotor 16 with a ported rotor shoe 18 and
a cover plate 46, the rotor 16 being driven by a gear motor
11 (Figure 3) at about two revolutions per minute, with the
rotor 16 turning in circumferential ball bearing unit 17.
Conic 1 disk or Belleville spring 35 urge$ cover plate 46
and rotor shoe 18 downward to secure them in position. The
rotor 16 and its associated ,components are enclosed by.
cover 21, which is attached to manifold 14.
Following the arrows indicating fluid f low direction,
the two-piece manifold 14 contains a top section 15 which
is ported and channeled to take in a stream of fluid
through the inlet port 6 and channel it through an air feed
passage 33- into a centrally located inlet port 19 in the
rotor shoe 18, and subsequently to channel the fluid
mixture exiting the rotor shoe radially from a circular
array of inlet ports located in the port plate 20 towards
each column 22 of an array of columns arranged about the
center of the manifold. Each of these columns contains a
bed of adsorbent material 24 (zeolite in this case) which
is selective for a particular molecular species of fluid or
contaminant. The packed bed is held in place by a plate

~ 1'O 93/16786 fCT/US92/01510
-8-
26 at the bottom and perforated plates 27 at top and bottom
with a spring 28 at the top. The bottom plate has a
pressure-dropping means such as a small orif ice 60, the
diameter of which is empirically determined, at the center
of each column.
The bottom half of the manifold, which is also an
upper column header plate 30, affixed to the top half of
the manifold by means of a clamp band 12, acts as a cover
for the channels and has the array of columns attached to
its underside. The channels in the manifold are sealed by
a gasket or sealing compound.
Recessed into the top of the manifold, coaxial to the
exit port of the air feed channel 33, sealed and
immobilized by means of a slot and key, is the port plate
20 which contains a number of holes in an equally spaced
circular pattern, equal in number and aligned with the
circular distribution of entry ports of channels to
individual columns in the manifold. The manifold has a
groove machined into its upper surface, just inside the
port plate, which contains an air inlet rotary seal 32.
The port plate is made from a suitable hardened material.
The other major component of the rotary distributor
valve is a gear motor-driven rotor. l6 containing a ported
rotor shoe 18, which slides over the rotor plate (Figure 5,
6, 7, and 8 all depict various aspects of the rotor/shoe).
The rotor shoe is made from material known in the art to be
suitable for use with the hardened material comprising the
port plate, and is held in position over the rotor plate by
spring-loaded or pressure compensated means. Shown is a
3o conical or Belleville pressure compensating spring to
counteract supply pressure. An arrangement of small coil
springs can also be utilized for this purpose.
In the rotor shoe, there are three channels. One
channel is a pressurizing channel or air feed passage 34
originating at the central fluid inlet port 19, and

WO 93/1G7R6 6 I'CT/US92/01510
~1~~
_g_
radiating into an arcuate-slot 36 to simultaneously.serve
as a conduit into several of the circularly positioned
ports in the port plate. As the rotor shoe turns, each new
port appearing in the slot is pressurized, and the port at
the other end of the slot passes out of the slot and is
depressurized. Full system pressure is maintained at all
intermediate ports. Figure 6, a sectional view taken on
line 6-6 of Figure 5, shows the relationship of the arcuate
air feed port or slot 36 of the rotor shoe 18 and the
receiving ports 38 in the port plate, as well as the air
feed channels 31 to each of the columns 22.
In another channel, the wide exhaust port 40 collects
refluxed fluid impurities desorbing and exiting from the
columns, and channels them out through an exhaust outlet 8
(Figure 5), through a "silencer" and into the atmosphere.
Figure 7 is a top plan view, partially cut away, of
the rotor shoe . Several other features come into view here .
The desorbed columns are vented upward through the exhaust
slot 40, through a vent 42 in the rotor shoe cover plate
46, into the rotor void space, and out through the exhaust
port 8 (Figure 5). , .,
The third channel is a cross-port channel 44 which
serves as a conduit between two columns which are in
transition between the pressurizing and desorbing phases of
a cycle. Its purpose is to quickly equalize pressure in
columns transitioning between the adsorbing and desorbing
cycles. This feature enhances product concentration at high
product flow rates.
The purge flow rate is the rate at which the purging
fluid flows countercurrent to adsorption during
regeneration of the columns. There is an optimal purge rate
for maximal removal of nitrogen during regeneration. A very
high purge rate causes the pressure within a bed to be
greater than atmospheric, resulting in reduced desorption
efficiency. The cross-porting channel in the rotor shoe

WO 93/16786 PCT/US92/01510
~~.xs~~..~v
-10-
allows a pressure drop in the column bed before it enters
the desorption cycle. This prevents a very rapid
decompression and thus excessively high initial purge flow.
This effect is easily measurable by simple instrumentation;
however, its basis at the molecular level is not
understood.
Figure 8 is a sectional view taken on line 8-8 of
Figure 7, showing the routing of the pressurizing 34,
cross-porting 44 and exhausting 40 channels in the rotor
shoe 18.
Figure 9 is a top plan view of the port plate showing
the circular location of ports of channels leading to each
of the array of columns, and Figure 10 is a sectional view
taken on line 10-10 of Figure 9.
Figure 11 depicts an alternative embodiment of the
apparatus of this invention, with a sectional view taken on
line 12-12 thereof shown in Figure 12. This latter view
shows an array of adsorber columns similar to the columns
22 depicted in Figure 4. As~in Figure 4, twelve columns
are the preferred number shown in the embodiment of Figure
12, but there could be any number of tWo or more. It
should be noted, however, that a length to diameter ratio
of greater than 6:1 for the adsorber columns is preferred
with the only limit on length being a practical one. This
ratio permits the adsorption medium to be retained within
the columns without the use of springs to compress and
retain the adsorption media therein. At least one layer of
filter media must, however, be present at each end of the
column to avoid loss of adsorption medium through the inlet
and outlet orifices to and. from the columns. A cap 165
will be mechanically seated over the distal end of each of
said columns, through which outlet orifice (not shown) to
product tank 130 (Figure 13) extends.

1V0 93/16786 ;; ,~ _.,, ; , PCf/US92/01510
-11-
The rotary distributor valve depicted in Figure 13,
which is an enlarged sectional view taken on line 13-13 of
Figure 12, comprises a manifold 70 which is formed from one
or more layers of aluminum, which layer or layers are
pierced, and/or die formed or embossed and then, if a
multiplicity of layers is used, sealed in a stacked
configuration (by lamination or equivalent means) to form
fluid channels. Four layers of aluminum (74, 75, 76 and
77j -are shown in Figure 13; it will be appreciated,
l0 however, that one or more layers of any lightweight, rigid,
low density material (such as a-b-s resin plastic] may be
used.
The rotary valve further comprises a rotor shaft 80
rotatably retained within bearing housing 81 and within
rotor shoe 85. Rotation of rotor shaft 80 is permitted by
the presence of O-ring 92 around its circumference. Rotor
shaft 80 is driven by gear motor 90 via motor shaft 135 at
about one revolution per minute. As depicted in Figure 13,
said rotor shaft 80 is concentrically shaped above line 91
and eccentrically shaped below line 91. The eccentric
shape is achieved by enlarging the lateral thickness of
side wall 80A of rotor shaft 80 with respect to side wall
80B.
Rotor shoe 85 comprises a ported disc (similar in
structure and composition to rotor shoe 18 depicted in
Figure 7j with raised side walls 86 and 87 which define a
circular chamber into which rotor shaft 80 is seated.
Rotor shoe 85 is driven by torque exerted by rotor shaft 85
when the latter is driven by gear motor 90. Compression
spring 93 assists in sealing the shaft and shoe, thus
maintaining the seal even when the apparatus is not in
operation and compensating for wear experienced by the
shaft and shoe. Use of this configuration to form a
pressure balanced seal requires less torque to turn the
rotor, and thus less energy to operate the system than

1Y0 93/ I 6786 fCT/US92/01 ~ 10
--
-12-
required by prior art systems or the embodiment of Figures
3-10.
The pressure balanced seal between the rotor shaft and
shoe is a function of the integrated pressure exerted on
the surface of the rotor shoe between it and the rotor
shaft during operation of the apparatus and the diameter of
the rotor shaft. During operation, the fluid pressure at
fluid inlet port 109 at the start of adsorption multiplied
by the diameter squared of the rotor shaft (below line 91)
and by n/4 is equal the force exerted to form a seal
between the shaft and shoe. As a result- of this
relationship, the shaft and shoe will remain sealed and
balanced with respect to each other even if the fluid
pressure at fluid inlet part 109 varies. It should be
noted that there is a passage~(not shown) from port 109
through to the interface surface between rotor shaft 80 and
rotor shoe 105 which serves to pressurize the interface to
help maintain the pressure balanced seal.
This apparatus also features an enhanced noise control
design. As shown in Figure 13, said noise control design
comprises muffler housing 100, having inner and outer
surfaces preferably formed by a flexible plastic, which
snaps over manifold 70 to forma cover for the manifold and
rotary valve distributor. The noise control design further
consists of pieces of acoustical foam or equivalent
acoustical attenuating material placed within the apparatus
as follows: at 101, said foam conforms topographically, in
one or more pieces, to the inner surface of muffler housing
100. At 102, acoustical foam is seated vertically between
bearing housing 81 and manifold 70. Said foam 102 may be
retained in place by a portion of layer 74 of manifold 70
formed to provide a stop 103 between foam 102 and port
plate 105.

Wn 93/IG786 ,_ _ .~ ~PCT/US92/Oi510
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-13-
In operation, sound waves emitted by the operation of
the rotary valve distributor escape from exhaust ports 113
and 114 in the rotor shoe into the annular air space 150
between the shoe and acoustical foam 102. Those sound waves
not dissipated by striking foam 101 and 102 eventually
escape from slots 107 in the walls of muffler housing 100.
The noise control design would, therefore, be considered in
the art as a reactive muffler.
Recessed into layer 74 of manifold 70 is port plate
l0 105. Port plate 105 is similar in structure to port plate
20 of the embodiment depicted in Figure~5, except that,
while the inlet ports therein to the adsorber columns (one
port per column) may be of any .shape, they are preferably
in the shape of wedges and most preferably in a arched
keystone shape which will circumscribe the orifices 160
leading into the columns 115 via air fed channels 116
(Figure 14). Wedge-shaped inlet ports are best depicted at
106 of Figure 14, which is a sectional view taken on line
14-14 of Figure 13.
As in the embodiment of the apparatus shown in Figures
3-10, fluid is directed to the. inlet ports 106 in port
plate 105 for passage to the adsorber columns via channels
in the rotor shoe. As best depicted in Figure 15, rotor
shoe 85 comprises three sets of channels. The first set of
channels consist of pressurizing channels 110A and 1108
which extend respectively and radially from central fluid
inlet part 109 to symmetrical air feed ports 111 and 112
(while two air feed ports are shown, it will be appreciated
that more than any number of two or more may be used as
long as the ports are arranged in axial symmetry about
inlet port 109). In terms of direction of flow, fluid
travels through fluid inlet port 109 to air feed ports 111
and 112 through ports 106 in port plate 105 to air feed
channels 116 (shown in Figure 14) which lead from each port

~LWO 93/16786 - _ _.~. ~~'/US~J1/01510
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106 to an adsorber column (shown in sectional view in
Figure 14 at 115).
The second set of channels consist of at least two
exhaust ports (113 and 114 in Figure 15) which will be
equal in number to air feed ports 111 and 112 and will also
be arranged with axial symmetry with respect to inlet port
109. The desorbed columns are vented upward through
exhaust ports 113 and 114, to annular air space 150 and
eventually to the atmosphere via slots 107 in muffler
housing 100 (Figure 13).
The third set of channels are at least one pair of
symmetrical cross-port channels 118 and 119 (equal in
number to air feed ports 111 and 112). These channels
serve to quickly equalize pressure between columns
transitioning between the adsorption and desorption phases
much in the same manner as does the single cross-port
channel 44 depicted in Figure 7.
The number and symmetry of shape and size common to
each set of channels avoids the preloading spring which
results from the use of asymmetrical ports, where variances
between the fluid pressure present at the air feed and
exhausts ports may push the rotor shoe against the port
plate during operation.
Excepting the points of difference described above,
the apparatus of Figures 11-17 is substantially similar to
the apparatus of Figures 3-l0.
The preferred method of fractionating air to provide
an oxygen-rich air supply to a patient is described below.
Fractionation Method
At this point it is reiterated that although air
fractionation is described, the method is effective in
fractionating other fluids.
In the embodiment of the apparatus of Figures 3-10,
the method of fractionation is as follows: compressed air
enters the inlet port 6 of the manifold (Figure 6) and is

A i . . r,
PCT/US92/01 ~ 10
WO 93/ 16786 1 ~ ~ ~
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channeled through the air passage in the manifold 33
communicating with the rotor shoe 18 and then into the
arcuate pressurizing slot 36 to enter sequentially into
several ports 38 in the port plate as the rotor shoe 18
turns. As these ports become pressurized, the gas mixture
enters, pressurizes and flows through each attached column
22 where the separation takes place.
Referring now to Figure 5, the desired gas, oxygen in
this case, is free to move through the zeolite -adsorbent
l0 bed 24 (e. g., similar to that provided by the molecular
sieve division of UOP), while the undesired gases and vapor
(nitrogen plus CO~, CO, HBO) are retained, because of their
molecular size and the relatively high pressure and low
temperature, in the matrix ':f the adsorbent bed.
The purified desired gas product (oxygen) moves out of
the column through a pressure-dropping means such as a
small orifice 60 or a fluid porous plug in the bottom of
the column and into the circumscribed product tank 9. From
the product tank, a relatively small portion of the oxygen
is tapped off by the distribution system conduit at the
outlet port 7 (Figure 6) fox use by the patient, and
another, relatively large, portion enters the columns in
the opposite bank, which are under nearly atmospheric
pressure, through a corresponding small pressure
dropping/flow restricting orifices in the bottom to reflux
through the bed in a direction opposite to gas flow during
pressurization. The amount of product used.to purge versus
the amount delivered by the distribution system can vary,
depending on the degree of product purity desired. This
backwash of product gas at pressure lower than the
adsorbing cycle removes the contaminant embedded in the
zeolite matrix, in this case nitrogen, and f lushes it out
through the top of each column into the manifold 14, the
port plate 20 and through the rotor shoe 18 and exhaust
outlet 8 into the atmosphere via a silencer or muffler.

___._ -._. _ -~O 93/16786 _.. p~/US92/015111
-16-
Referring back to Figure 2, the tapped oxygen-rich
product gas then moves within a dispensing conduit 46
through a manually controlled valve 50 with a flow meter,
through a final filter (HEPA) 52 and to the dispensing
terminus.
In the embodiment of the apparatus shown in Figures
il-17, the method of fractionation is as follows:
compressed air enters the manifold from inlet conduit 120
through inlet port 121 (Figures 14 and 17) and is channeled
through channel 71 communicating with the rotor shoe 85 via
central fluid inlet port 109. The air then passes through
radial channels 110A and 110B to inlet ports 111 and 112.
As the rotor shoe turns over port plate 105, inlet ports
111 and 112 will each become aligned with an equal
plurality of wedge-shaped ports 106, thus allowing the air
to enter the columns 115 via air feed channels 116
corresponding with each plurality of ports 106 served
respectively by inlet ports 111 and 112. Adsorption
occurs within the columns as described above.
The purified product is retained within product tank
130 after exiting the column via pressure-dropping means
such as orifice 60 depicted in Figure 5. Product tank 130
(Figure 11) differs from product~tank 9 (Figure 5) in that
tank 130 is smaller in volume and does not surround columns
115 except at their distal ends; i.e., opposite manifold
70. This smaller product tank (vis-a-vis product tank 130
[Figure 11]) reduces the overall weight of the system. As
will be understood by those skilled in the art, the limits
on reduction of the size of product tank 130 are practical
ones, principally dictated by storage needs and the volume
required to regulate the output pressure of the system
sufficiently well to reduce the need for a pressure
regulator.

W() 93/16786 PGT/US92/01510
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-17-
Product is tapped for use by the operator or patient
via outlet conduit 125. The system is then purged as
described above with respect to the method used with the
apparatus depicted in Figures 3-10.
In both embodiments and methods described above, when
the motor is operated at the specified speed (i.e., 1
revolution per minute for the embodiment of Figures 11-17
and 2 revolutions per minute for the embodiment of Figures
3-10) , and the inlet and exhaust ports in the rotor shoe
are equal in size, the cycle profile is such that each
column is pressurized for approximately 12.5 seconds,
equilibrated for 2.5 seconds, and desorbed for 12.5 seconds
and re-equilibrated. This profile of the cycle is
obtainable only when the intake and exhaust slots in the
rotor shoe are equal in size, and service an equal number
of columns. The profile can be altered as desired by
varying the size of the respective inlet and exhaust ports.
This is a desirable feature which cannot be put into effect
in any of the prior art mechanisms.
As the rotor rotates over the rotor plate, this cycle
is sequentially and continuously established for each
column. This mode of operation produces a relatively
constant flow of product, improving with a greater number
of columns, eliminating the need for a pressure reducing
regulator. The average product outlet pressure is nearly
constant and about twice the regulated delivery pressure of
prior art fractionators.
Some other advantages of the present invention are
outlined hereunder. Because of the large number of
relatively small diameter adsorber columns, the column
length may be short, even with a large length: diameter
ratio which is essential for effective adsorption
separation. The large number of columns and the rotary
distributor valve result in a quasi steady-state gas flow
through the compressor and other components which produces

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- 1 8 _
a number of advantages and system simplifications. The
invention permits optimization of the adsorption cycle by
providing the possibility~of employing unequal times for
the adsorption and desorption phases of the cycle. Prior
art two chamber systems are inherently bound to equal
times.
Another notable advantage of the invention is the
elimination of many~components which are necessary in the
prior art, thereby, reducing size, weight and the amount of
to maintenance, concomitantly increasing reliability and
maneuverability for the ambulatory patient. These
eliminated components include:
Air receiver or surge tank
Four or five solenoid valves (or a 4-way valve and one
2-way solenoid valve).
Electric or electronic sequencing control for the
solenoid valves
Pressure reducing regulator
Almost all connecting tubing and fittings
The elimination of almost all "plumbing" decreases
size and weight, the potential for system leaks and reduces
manufacturing costs.
Although the adsorbent material utilized in this
embodiment is a synthetic zeolite, there are many other
useful adsorbents available; therefore, this invention
should not be construed as restricted to its use. It is
understood by those well versed in the art that many other
configurations are possible while employing the rotary
distributor concept, which are within the spirit and scope
of this invention.
WE CLAIM:

Representative Drawing