Molecular sieve abstract
A molecular sieve material for removing water from a liquid, such
as distilled alcohol produced from grain, is placed in a series
of concentric cylindrical spaces of narrow but equal width and separated
by concentric cylindrical passages of lesser width, through which
a heated gas, such as air containing the gaseous product of combustion
of a fuel, is passed for heating the material for regeneration.
After heating, the material is cooled by a gas, such as air, through
the same passages. The cylindrical sleeves forming the spaces and
passages are relatively thin and the spaces are closed at opposite
ends by annular rings to which the sleeves are attached, as by welding,
with spacing blocks at spaced points in the passages. Additional
rings, of slightly less width than the spaces, are spot welded just
inside the end rings to permit flow of liquid but retain the sieve
material. The entire structure is preferably upright, enclosed by
an insulated housing, and liquid is passed to the bottom and removed
from the top of the spaces by headers connected by tubes with the
respective spaces, while a water cooled condenser is connected to
the outlet. A pipe for conveying heated air from a burner, ahead
of a blower, connects with the lower end of the housing, with an
outlet pipe at the top for recirculation. A down pipe connects the
top and bottom air pipes and is offset above a slide shut-off valve
above a flap suction valve which permits outside air to be sucked
in for cooling. During cooling, a weighted flap valve on the upper
pipe permits discharge of exhaust air.
Molecular sieve claims
What is claimed is:
1. A method of removing water from a normally liquid fluid by a
molecular sieve material and regenerating said molecular sieve material,
comprising:
placing said material within a series of first concentric, elongated,
cylindrical spaces of limited thickness and separated by a series
of second cylindrical spaces interposed between said first cylindrical
spaces, with said second cylindrical spaces having a lesser thickness
than the first cylindrical spaces;
passing said normally liquid fluid through said material while
preventing any flow of said liquid fluid from said first cylindrical
spaces into said second cylindrical spaces, until said molecular
sieve material becomes sufficiently saturated with water that its
ability to remove water is impaired;
passing a heated gas through said second cylindrical spaces while
preventing any flow of said gas from said second cylindrical spaces
to said first cylindrical spaces, in order to regenerate said molecular
sieve material after passage of said normally liquid fluid is discontinued;
and
similarly passing a cool gas through said second cylindrical spaces
when sufficient water adsorbed by said molecular sieve material
has been driven off to resume circulation of said normally liquid
fluid through said molecular sieve material, in order to cool said
molecular sieve material to a temperature permitting resumption
of removal of water from said normally liquid fluid.
2. A method as defined in claim 1 including:
recirculating said heated gas along an essentially closed path
from one end of said second spaces to the opposite end of said second
spaces; and
reheating said heated gas during said recirculation.
3. A method as defined in claim 2 including:
supplying an oxygen containing gas and a fuel to a burner; igniting
said fuel; and
introducing the products of combustion into said recirculating
gas.
4. A method as defined in claim 2 including:
passing an ambient temperature, cool gas through said second spaces,
following heating of said material.
5. A method as defined in claim 4 wherein:
said cool gas is drawn from the atmosphere and passed through a
portion of said closed path to said one end of said second spaces;
and
said cool gas is exhausted to the atmosphere after passage through
a portion of said closed path leading from said opposite end of
said second spaces.
6. A method as defined in claim 1 including:
draining normally liquid fluid from said material prior to heating
for regeneration; and
collecting said drained liquid for subsequent passage through said
material.
7. A method as defined in claim 6 including:
condensing gaseous products produced during heating of said material.
8. A method as defined in claim 7 including:
collecting condensed gaseous products having a water content no
less than the water content of said normally liquid fluid for subsequent
passage through said material.
9. A method as defined in claim 1 wherein:
said normally liquid fluid is alcohol having a water content of
about five percent; and
said alcohol is produced from a mash and distillation of the alcoholic
product of said mash.
10. A method as defined in claim 9 including:
draining alcohol from said material prior to heating for regeneration;
collecting said drained alcohol for subsequent passage through
said material;
condensing alcohol and water vapor driven off said material by
heating;
collecting a first condensed alcohol having a water content of
about five percent or less for subsequent passage through said material;
and
separately collecting a second condensed alcohol having a water
content between about five percent and the water content of the
product of said mash which is distilled; and
distilling said second alcohol.
Molecular sieve description
This invention relates to the regeneration of molecular sieve material
and, more particularly, to the regeneration of molecular sieve material
which is used to reduce the water content of alcohol, as to increase
the proof thereof from 190 to 200.
BACKGROUND OF THE INVENTION
In the production of alcohol from grain for use in making what
is termed "Gasohol", a mixture of gasoline and alcohol,
it is necessary to reduce the moisture content of alcohol before
mixing with gasoline to essentially zero, which is equivalent to
a proof of 200 since any water in the alcohol reduces the effectiveness
of the gasoline. The alcohol being liquid may be produced by a mash
fermented from grain or other suitable materials. In the usual stills
which evaporate alcohol produced from mash, the alcohol still contains
an undesirable amount of water, the proof thereof normally approaching
190 or 5% water.
A molecular sieve material, such as Type 3A molecular sieve manufactured
by Union Carbide Corporation and also by W. R. Grace and Company
is particularly useful in removing the moisture or water and producing
a 200 proof alcohol. Such molecular sieve material is available
in the form of granules and may be placed in a container through
which the 190 proof alcohol is passed, so that the molecular sieve
material absorbs the water. For a production operation, in which
down time is of the essence, the molecular sieve material must be
regenerated whenever it becomes essentially saturated with water,
and therefore fails to produce the desired proof of alcohol. Such
molecular sieve material may be regenerated by heat, but it requires
an undue amount of time to heat any substantial size of bed of such
material. Thus, the time required for regeneration of a substantial
size bed may approach the time during which the bed is operative
to produce the desired results. This means that there is no production
of the desired alcohol for approximately 50% of the time.
It has been proposed to revivify carbonaceous absorbents such as
bone char, as in U.S. Pat. No. 2851428 by passing the char downwardly
through parallel tubes surrounded by a heating medium, preferably
heated gases. Also, U.S. Pat. No. 2222304 discloses a method and
apparatus for catalytic reaction in which the catalytic reaction
is controlled by circulating a temperature controlled heat exchange
medium in heat exchange relationship with the material in a contact
bed which has a relatively greater length in proportion to its transverse
dimension by passing the heat exchange medium through tubes provided
with outwardly extending fins or plates. However, the distance between
the tubes is much greater than would permit an adequate and sufficiently
fast transfer of heat for regeneration of a molecular sieve material.
Of course, the catalyst, itself, is regenerated by passing in an
oxidizing medium through the bed, while maintaining circulation
of the heat transfer medium. Neither of the foregoing appear to
suggest a satisfactory solution to the problem of producing a fast
enough heating of a molecular sieve material for regeneration thereof,
accompanied by a relatively fast cooling thereof to place the material
at the temperature suitable for further extraction of water or moisture
from alcohol. Since the removal of water or moisture from alcohol
by a molecular sieve material is exothermic and the material tends
to become heated during reaction, it is necessary that the molecular
sieve material be returned to a lower temperature, such as 200.degree.
F., prior to initiating further removal of moisture.
SUMMARY OF THE INVENTION
In accordance with this invention, a molecular sieve material adapted
for the removal of moisture or water from alcohol is placed in a
series of concentric circular spaces of narrow width and, more particularly,
a width which is essentially merely a fraction of the circumference.
Between each such space for containing a molecular sieve material
is a passage which may have a considerably less thickness than the
aforesaid space through which heated air is passed for regeneration
of the molecular sieve material. The air passages are concentric
and circular, while both the molecular sieve spaces and air passages
should have as uniform a width as possible, completely around the
peripherty thereof. Any flow of the liquid, such as alcohol, from
the spaces containing the molecular sieve material into the heated
air passages is prevented and, similarly, any flow of air from the
air passages to the molecular sieve spaces is prevented. In further
accordance with this invention, the imperforate walls or shells
forming the circular spaces and annular air passages are comparatively
thin so as to increase the rate of heat transmission from the heated
air to the molecular sieve material.
The assembly of concentric enclosed spaces is installed in a vertical
position within a tower for passage of the heated air and later
cooled air through the passages from a bottom air reception space
to an upper air discharge space to provide the desired high temperature
such as 500.degree. F. or above. The air is recirculated without
the introduction of fresh air except at a burner, to which fuel
and air are supplied, the latter being a blower with the products
of combustion being completely discharged into the air stream which
moves from a blower through a pipe to the lower end of the tower
from the upper end of the tower. The air cooled somewhat by passage
through the tower passes downwardly to the inlet of the blower and
past the burner to pick up additional hot products of combustion.
When the regeneration is complete, indicated by the fact that water
vapor is no longer driven off from the molecular sieve material,
the burner is turned off and air is no longer recirculated, but
rather fresh air is supplied to the blower by blocking off the recirculation
pipe just prior to the blower and permitting fresh air to be drawn
in by a special valve, with the cool, outside air being forced by
the blower through the passages in the tower and discharged from
the upper pipe through a flap valve which is responsive to a pressure
which exceeds the normal recirculating pressure. The normal recirculating
pressure is comparatively low because the discharge space in the
tower is connected with the suction side of the blower. The termination
of recirculation for cooling is accomplished by a slide valve in
the down pipe just above the blower.
A condenser is provided for condensing any alcohol vaporized by
exothermic reaction of moisture and water removal. The condenser
is also utilized in condensing water vapor driven off the molecular
sieve material during regeneration.
The spaces for containing the molecular sieve material are formed
by thin-walled shells extending longitudinally in narrow space relation
and attached as by welding to each other and to an annular ring.
In addition, special provision is made for maintaining the relationship
of the shell assemblies, as well as for accomodating expansion and
contraction of tubes which connect a lower alcohol inlet header
with the bottom of the aforesaid rings and an upper alcohol outlet
which is connected with the respective top rings. The entire tower
is insulated, as well as the pipe through which the heated air and
gases are recirculated.
THE DRAWINGS
FIG. 1 is a front elevation of apparatus adapted to carry out the
method of this invention
FIG. 2 is a partial end elevation showing particularly a condenser.
FIG. 3 is a limited horizontal section taken along line 3--3 of
FIG. 1 on an enlarged scale, with lower insulation broken away
to show a pipe and details of other parts.
FIG. 4 is a limited vertical section taken along line 4--4 of FIG.
3 and showing particularly a blower and a suction flap valve.
FIG. 5 is a limited vertical section, on an enlarged scale, showing
a flap valve installed on an upper pipe.
FIG. 6 is a condensed top plan view of a column assembly with a
top manifold shown fragmentarily and connections omitted.
FIG. 7 is a partially diagrammatic, condensed vertical section,
on a slightly reduced scale and taken along line 7--7 of FIG. 6
showing also an insulating covering of the column.
FIG. 8 is an enlarged fragmentary detail of an upper portion of
the column and connections to the sections thereof.
FIG. 9 is a similar enlarged fragmentary detail showing a lower
portion of the column and connections to the sections thereof.
FIG. 10 is a fragmentary horizontal section, on an enlarged scale
and taken along line 10--10 of FIG. 1 showing particularly an upper
pipe connection to the column.
FIG. 11 is a similar fragmentary horizontal section, on an enlarged
scale and taken along line 11--11 of FIG. 1 showing particularly
a lower pipe connection to the column.
FIG. 12 is a bottom plan view of the column with connections omitted,
but showing particularly supporting bars for the column.
FIG. 13 is a fragmentary top plan view, on an enlarged scale, showing
a portion of the top of the column and also showing spacers between
upright sections.
FIG. 14 is a side elevation looking toward the outside of the column
sections shown in FIG. 13 and also showing the spacers.
FIG. 15 is a fragmentary horizontal section, on an enlarged scale
and taken along line 15--15 of FIG. 1 showing particularly an access
port for the base of the column.
FIG. 16 is a side elevation, on an enlarged scale, of a stress
relief loop shown diagrammatically in FIG. 7 of the tube connections
for the base of the column.
FIG. 17 is an enlarged sectional detail showing a filling connection
at the top of a section of the column.
FIG. 18 is a similar detail in longitudinal section, showing a
discharge connection at the bottom of a section of the column.
FIG. 19 is a side elevation on a reduced scale of a filling device,
similar to a funnel, forming part of the filling connection of FIG.
17.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In FIG. 1 is shown an apparatus adapted to carry out the method
of this invention, including an insulated tower T, within the interior
of which is a column especially constructed in accordance with this
invention which permits the removal of water or moisture from a
relatively high-proof alcohol by a molecular sieve material, the
regeneration of which is accomplished in accordance with this invention,
when the molecular sieve material becomes saturated with water.
As indicated previously, the molecular sieve material may be selectively
absorbent of water or water vapor, but requires regeneration periodically,
through heating. The 190 proof alcohol may be produced by a conventional
plant which includes a mill for grinding the grain, a cooker to
which hot water is supplied by a boiler, a saccharification tank,
a pluality of fermentation tanks, a still for concentrating the
alcohol liquid produced and feed tanks for storing the 190 proof
alcohol.
In the present instance, heating is accomplished by circulating
heated gas through special annular passages interspersed with enclosed,
annular sections in which the molecular sieve material is contained,
and the construction of which will be described in greater detail
later. The alcohol, such as 190 proof or containing only 5% moisture,
enters the tower through a bottom inlet pipe 10 and is discharged
through an upper oulet pipe 11 for passage through a condenser
C, of conventional construction, which is desirable during absorption
because the reaction between the moisture in the alcohol and the
molecular sieve material is exothermic and tends to heat the alcohol,
but is also necessary during regeneration. Thus, any alcohol vapors
produced during adsorption by the molecular sieve material is condensed
to liquid in the condenser C. The alcohol, including the alcohol
vapors condensed, are discharged from the condenser through a pipe
12 at the lower end so that the alcohol and cooling liquid, normally
water, will pass in counter-current relation through the condenser.
Thus, water is introduced through a lower inlet pipe 13 and discharged
through an upper outlet pipe 14. The alcohol outlet pipe 12 as
in FIG. 2 is provided with a branch 15 having a valve 16 interposed
therein, for normal flow of alcohol to a collection tank, in a conventional
manner. Another branch 17 having a valve 18 is utilized for the
passage of alcohol from which the water vapor has not been completely
stripped to water containing little alcohol. When the proof exceeds
190 such higher proof alcohol may be stored in another tank and
rerun through the molecular sieve material after the next regeneration.
Or, lower proof alcohol may be returned to the mash tanks, while
water condensate having little or no alcohol may be drained to a
sewer. Thus, by closing valve 18 and opening valve 16 the normal
flow of essentially 200 proof alcohol to the collection tanks therefor
may be obtained, while by closing valve 16 and opening valve 18
a flow of high-proof alcohol to a collection tank may be obtained
or other disposition of the condensate may be made. Condenser C
is mounted on tower T by brackets 19 of FIG. 2.
When the molecular sieve material requires regeneration, the alcohol
remaining in the spaces containing material may be first drained,
as through inlet pipe 10 and returned to the 190 proof feed tanks
in a manner described later.
When regeneration is first started, alcohol vapors, having a lower
boiling point than water, will tend to be driven off the molecular
sieve material first, for passage through the condenser and this
condensate is diverted through branch 17 to the collection tanks
for higher proof alcohol. However, as soon as the vapors driven
off from the molecular sieve material begin to contain substantial
water vapor, the condensate may be passed through the branch 17
for purposes described above.
The apparatus of FIG. 1 for regeneration purposes, includes an
insulated lower pipe L through which air, heated by a heater H and
including the products of combustion of the heater, is circulated
by a blower B for passage upwardly through the column containing
molecular sieve material within the tower T. The cooler gases exhaust
from the tower through an insulated upper pipe U having a flap valve
F which is in use only when cool air is being blown through the
tower for cooling the heated molecular sieve material, after regeneration.
From the upper pipe U, air circulates through an insulated down
pipe D past a slide valve V, which is also only used during cooling
after regeneration, and then past a suction valve S of FIGS. 3 and
4 again utilized only during cooling. The gases then return to
the blower B and move past the heater H for reheating, picking up
additional products of combustion of the heater. During such recirculation
of heated air, the air may approach a temperature of 500.degree.
F. to 600.degree. F., which results in a relatively fast regeneration,
thereby reducing considerably the downtime during which no alcohol
can be purified.
Due to the heat required for fast regeneration, the molecular sieve
material is at a temperature which is greatly above the boiling
point of alcohol and must be cooled before the purification process
can begin again. For cooling, the slide valve V in the down pipe
D is closed, to preclude recirculation of air. The heater H is turned
off, but the blower B is operated at full speed so that cool, outside
air is sucked in through the suction valve S and passes through
the special passages provided by this invention to cool the molecular
sieve material, and is exhausted to the atmosphere through the flap
valve F on the upper pipe U, since recirculation is precluded by
the closed slide valve V. It should be emphasized that neither the
heated air for regeneration or the cooler air for cooling ever contacts
the molecular sieve material, so that the relative humidity of the
outside air cannot be a problem.
As in FIGS. 3 and 4 the slide valve V may include a slide plate
21 which is guided by a channeled housing 22 to and from positions
opening or closing off the passage through the down pipe D. The
suction valve S is disposed within a rectangular housing 23 open
at both ends, with the outer end being open to the atmosphere and
the inner end extending to the down pipe D. The suction valve is
provided with a pivoted plate 24 which normally rests against an
inclined guide bar 25 at each side, but when sufficient suction
is produced by the blower B, will raise to permit outside air to
be drawn into the blower B through an elbow 27. Each of the upper
and lower pipes, as well as the down pipe, are provided with insulation
26 as is also the tower T. The insulated blower B may include a
squirrel cage impeller 28 having inclined vanes disposed in a ring
as shown, and supported and driven by a shaft 29 in overhanging
relation to, but closely adjacent to a bearing 30. The blower impeller
is disposed within a housing 31 appropriately constructed to permit
an axial intake and a tangential discharge into a duct 32 connected
to lower pipe L at a conventional flanged joint 33. Outside the
insulation 26 as in FIG. 3 shaft 29 extends through a second bearing
35 to a pulley 26 connected by V-belts 37 with a pulley 38 of a
drive motor 39.
The heater H is provided with a conventional burner 40 supplied
with an appropriate fuel, such as a liquid or gaseous hydrocarbon,
through pipe 41 and is supported by a pedestal 42 of FIG. 1. A motor
driven blower 43 is mounted on the burner in a position to discharge
air tangentally into the burner to produce a spiral effect and increase
the combustion of fuel in order to provide products of combustion
having as high a temperature as possible. As indicated previously,
the gaseous products of combustion discharge from the burner 40
into the lower pipe L and are carried along with the recirculated
air.
As in FIG. 5 the flap valve F extends through the insulation 26
on the upper pipe U, having a rectangular housing 44 the upper
end of which is cut off at an angle so that a flat plate 45 may
be pivoted at the lower edge of the upper end of the housing 44
as by pin 46. The flap plate 45 will normally remain in engagement
with the upper edges of the housing 44 until the pressure inside
the upper pipe becomes sufficient to lift the flap plate. An upwardly
inclined stem 47 of the flap plate 45 may be narrower than the remainder
thereof, but adds sufficient additional weight.
The hollow spaces containing the molecular sieve material are circular
and the sections which provide the spaces are interspaced with the
circular hollow passages through which air is blown for regeneration
or subsequent cooling of the molecular sieve material. As in FIGS.
6 and 7 an inner circular sleeve 49 is spaced relatively close,
such as 1/4", to a cylindrical section formed by a pair of
thin-walled, upright circular sleeves 50 and 51 which are joined
at the top to an annular ring 52. Inner sleeve 49 and sleeve 50
form an air passage 53 while the outside sleeve 51 and the inside
sleeve of the next section form a similar air passage of greater
diameter. Similar air passages, of the same width but successively
increasing diameters, are formed between successive sections, while
a thin-walled outer sleeve 54 forms an air passage 53 with the out
side of the outermost section. The hollow center within inner sleeve
49 is closed off at each end by a disc 55 of FIGS. 7 and 12. As
in FIGS. 8 and 9 not only are the thin-walled sleeves 50 and 51
attached to an annular ring 52 at the top, but also to an annular
ring 56 at the bottom, to provide an enclosed space 57 for receiving
the molecular sieve material, such as indicated previously. Space
57 is wider than air passage 53 such as 1", in order to provide
considerably greater cross-sectional area for reception of the molecular
sieve material, but still provide passages through which air may
be blown and permit transfer of sufficient heat to or from the molecular
sieve material. Outwardly of the outermost sleeve 54 of relatively
thin material is an outer wall 58 which is considerably heavier
and provides stability for the tower T. For instance, the sleeves
forming the air passages and the spaces for the reception of molecular
sieve material, may be formed of 12 gauge material, while the outer
wall 58 may be one-fourth inch thick. Outer sleeve 54 may be thicker
than the remainder of the sleeves since, as in FIG. 7 it extends
downwardly to the bottom of the tower and upwardly to the top of
the tower, to hold insulation between it and outer wall 58.
As also illustrated in FIG. 7 cylindrical outer wall 58 extends
downward to a base plate 60 to which it may be welded and upwardly
to a top plate 61 which may be removably attached to wall 58 in
a conventional manner, as by being bolted to an outwardly extending
flange of the wall, as shown. Below the column forming the air passages
and spaces for sieve material and above base plate 60 is a lower
space 62 with which lower pipe L connects and which provides sufficient
space for making connections or repairs to an alcohol inlet manifold
63 which connects with inlet pipe 10. Air is exhausted from the
air passages through a similar upper space 64 with which upper upper
pipe U connects, and through which extends an outlet or upper manifold
65 which is connected to outlet pipe 11. Each manifold 63 and 65
extends at each end through the outer wall 58 both for greater
stability and also to permit the respective inlet or outlet pipe
to be connected to either end of the corresponding maifold. Manifolds
63 and 65 are preferably square or rectangular to enable the lower
tubes 66 and upper tubes 68 to be attached in staggered relation
thereto and also to permit them to extend through a corresponding
hole in outer wall 58 the better to resist twisting.
As in FIGS. 10 and 11 the angular relation of lower pipe L and
upper pipe U to the tower T are different. The lower pipe L is aligned
with the center of the tower, as in FIG. 11 while the upper pipe
U extends in an angular relation to approximately the position of
flap valve F, then parallel to the lower pipe L, in order to offset
the down pipe D from the lower pipe and thereby permit an axial
intake of the blower B. Each pipe L and U extends through a hole
in outer wall 58 and to a hole in outer sleeve 54.
As in FIG. 7 a series of tubes 66 connect the lower manifold header
63 with the lower rings 56 of the sections for containing molecular
sieve material, each tube having an expansion loop 67 to prevent
loosening of any connection during the temperature range produced
by the hot air during heating, and perhaps very cold air during
cooling, blown through the lower space 62. A series of similar upper
tubes 68 connect the upper manifold 65 with rings 52 at the upper
ends of the spaces for molecular sieve material. Tubes 68 may be
similarly provided with loops 67 although the variations in temperature
tend not to be extreme in the upper space 64 as in the lower space
62. Special connections are preferably utilized at each end of lower
tubes 66 and upper tubes 68 as will be described later. The entire
column providing the annular passages for air and the larger annular
spaces for the sieve material may be supported by a pair of bars
70 and 71 of FIG. 12 which extend beneath the assembly and through
the heavier outer wall 48 being welded to the outer wall on the
outside as shown.
As in FIG. 6 the upper tubes 68 and similarly, the lower tubes
66 extend in staggered relation downwardly from the outlet manifold
65 and upwardly from the inlet manifold, respectively, in order
to provide greater access to the connections at the ends of the
tubes. Appropriate connections between the upper and lower tubes
to the respective molecular sieve spaces are shown in FIGS. 8 and
9. The thin gauge material of the sleeves 50 and 51 are welded at
the upper ends to the corresponding annular ring 52 and at the lower
end to annular ring 56. However, prior thereto, an upper ring 72
and a lower ring 73 each smaller in width than the distance between
sleeves 50 and 51 is positioned inside the respective sleeves a
short distance from the upper and lower ends, respectively. Each
ring 72 and 73 is spot welded, as at positions a short distance
apart circumferentially, to the sleeves 50 and 51 to provide passage
for the alcohol and other vapors through the molecular sieve spaces,
but prevent the molecular sieve material from dropping into the
lower header or being carried out at the top by the alcohol flowing
through.
At an appropriate position, each lower annular ring 56 is provided
with a threaded nipple 74 at each side for engagement by a fitting
75 and at the upper end each annular ring 52 is provided with a
threaded nipple 76 at each side which is connectable to and disconnectable
from the upper tube 68 by a tube fitting 77.
The manifolds 63 and 65 are similarly provided with threaded nipples
for connection of the respective ends of the tubes thereto, it being
understood that the position of these nipples is staggered, such
as corresponding to the indication of the position of the tubes
68 in FIG. 6. For gaining access to the upper header and the connections
associated with the tubes 68 the top plate 61 may be removed. For
gaining access to the lower header and the connections associated
with the lower tubes 66 a cover 78 of FIG. 15 may be removed from
an insulated manhole 79 which extends through both outer wall 58
and outer sleeve 54.
In order to mount the thin-walled annular sections forming the
spaces for the molecular sieve material in position with respect
to each other and more particularly, to maintain the width of the
smaller air passages uniform, a series of spacing blocks 80 of FIGS.
13 and 14 may be utilized. The spacing blocks 80 shown also in
FIGS. 8 and 9 are spot-welded to the outside of sleeve 51 of the
respective section at spaced positions, such as about 6" apart
and around both the upper and lower periphery of each section. The
spacing blocks 80 are slightly curved to correspond to the contour
of the outer sleeve 51 to which the respective block is attached,
and also to the inner sleeve 50 of the next outer section, which
abuts the spacing block, as in FIG. 13. The thickness of the spacing
blocks correspond to the thickness of the air passages 53 while
the width of the blocks is preferably a multiple of the thickness
and the length of the blocks is preferably a multiple of the width.
When circulation of alcohol is stopped because the molecular sieve
material requires regeneration, there will be 190 proof alcohol
in the sieve material, which can be returned to the storage tanks
therefor. For this purpose, a pump 82 as in FIG. 7 may have an
inlet provided with a normally closed valve 83 and an outlet provided
with a normally closed valve 84 connected to inlet pipe 10 on opposite
sides of a normally open valve 85 in pipe 10. By closing valve 85
and opening valves 83 and 84 then starting pump 82 the alcohol
in the column may be returned to the 190 proof tanks before regeneration
begins.
For filling the respective spaces with the molecular sieve material,
a series of filling connections spaced outwardly from each side
of center as in FIG. 6 and in staggered relation similar to the
tubes 68 may be utilized for filling purposes. The filling connections
87 as in FIG. 19 essentially funnel-shaped, are elongated in one
dimension and narrower in the other and provided with an interiorly
threaded circular collar 88 at the lower end so as to be capable
of being threaded onto a threaded nipple 89 of FIG. 17 which is
welded onto the upper end of a square tube 90 which extends through
the upper ring 52 of the respective space assembly, and downwardly
through a corresponding hole in the protective ring 72 within the
space. Square tube 90 is, of course, welded to both ring 72 and
ring 52 at the respective hole through which it extends or to which
it connects. Normally, the upper end of nipple 89 is closed by a
pipe cap, since the filling connections 87 are attached to the nipples
after removal of the pipe cap for filling purposes. Also, after
the molecular sieve material space is full, the filling connection
87 may be removed and the nipple 89 again closed by a pipe cap.
The filling operation can be conducted by removing the top plate
61. For draining the sieve material from the spaces, drain nipples
91 of FIG. 18 which may be smaller in size than the filling nipples
90 such as having a diameter of one half of the width of the space,
extend upwardly through the lower ring 56 and connect with a corresponding
hole in the protective ring 73 as in FIG. 18. The drain nipples
91 are conveniently located at opposed positions on the underside
of the rings 56 in staggered relation and in a position spaced
from the filling connections, such as perpendicular to the staggered
row of filling connections. The drain nipples 91 are normally closed
by pipe caps, which can be removed for draining used molecular sieve
material into the lower space 62 and removal of the used material
through an opening uncovered by removal of the access cover 78.
Although this invention has been described with particular reference
to the regeneration of molecular sieve material used in the removal
of water from alcohol, it will be understood that the method and
apparatus of this invention may be utilized for the regeneration
of similar material used in the removal of other liquid or vapor
from other liquids. It will also be understood that other embodiments
of this invention may exist and that variations and changes may
be made without departing from the spirit and scope of this invention. |