Note: Descriptions are shown in the official language in which they were submitted.
10639'~7
FEED SYSTEM FOR PACKED BFD
This invention relates to packed beds, and more
particularly, to a new and improved packed bed contacting apparatus
including new and improved means for introducing either a gas and/
or liquid into a packed bed.
Packed bed systems are process vessels in which one
or more fluids ~low through a bed of solid particulate material,
such as balls, Raschig rings, saddles,catalyst partlcles, etc.
Flow through packed beds may be one of any of several modes such
as gas-liquid, gas, liquid, and liquid-liquid. In all of these
systems, the gas and/or liquid is generally introduced into the
bed through a suitable distributor such as weir boxes, chimney/
sieve plates, etc. which are supported on a horizontal plane with-
in the vessel, resulting in independent support structures which
are not only costly but also frequently result in superfluous
vessel height. In systems which require unusual physical and/or
chemical properties for the materials of construction, such as,
in high temperature and/or corrosive environments, such devices
together with their support structures are not only costly, but
are difficult to design and implement. In most cases, this
independent support structure incorporates structural devices
such as beams or trusses, and in cases where metal is not
practical, the use of stoneware arches or domes. As vessel
diameters increase, the cost of the internal structure increases
disproportionately. Accordingly, there is a need for new
and improved means for introducing a gas and/or liquid into a
packed bed.
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10~39Z7
In accordance with one aspect of the present invention,
there is provided a contact~ng apparatus having a packed bed
and a plurality of separate liquid distributors distributed
throughout the packing of the packed bed, with the distributors
being supported within and solely by the packed bed whereby there
is no need for separate support structure structurally connected
to the vessel walls.
More particularly, there is provided a plurality of
liquid distributors which are dispersed within and supported by
the packed bed, with one of the distributors being a main
distributor and preferably being centrally located within the
packed bed. The remaining distributors are distributed throughout
the bed on a horizontal plane below the main distributor, and the
main distributor is interconnected with each of the remaining
distributors, whereby liquid feed can be introduced into the
main distributor, and distributed therefrom both directly into
the bed and into each of the branch distributors. The liquid
feed introduced into the branch distributors is then distributed
into the packed bed. The distributors employed for separately
~ 20 introducing the liquid into the packed bed may be any one of
- those typically employed in the art, including perforated dis-
tributors and weir boxes. By placing a plurality of distributors
below the plane of the main distributor the liquid feed can flow,
by gravity, from the main distributor into the remaining
distributors.
In accordance with the present invention, the
individual distributors of the overall liquid distributing system
carry small loads on small spans, and the total load of the
1063~Z;7
distributor system iY carried by the packed bed. In this manner,
the liquid distributing system is independent of the bed diameter
or height. The distributor components can be fabricated of any
material which meets the requirements for the process to be
effected in the bed, such as, chemical inertness, physical strength
and the like. The materials may be metal, stoneware, polymers,
etc.
In accordance with another aspect of the present
invention, there is provided a contacting apparatus including
a packed bed, a gas plenum chamber within the packing of the
bed, and a plurality of gas distributing means supported by and
within the packing of the bed for distributing gas from the plenum
chamber into the packing of the bed. In this manner, as in the
case of the liquid distributing means of the present invention, -
the gas distributing means for introducing gas into a packed bed
is independent of the vessel wall, and is supported by and
within the packing of the bed. As in the case of the liquid
distributing system of the present invention, the components
of the gas distributing system may be formed of materials
suitable for the requirements of the process, and such materials
may include metals, stoneware, polymers, etc.
The invention will be further described with respect
to the accompanying drawings, wherein:
Figure 1 is a sectional view of a portion of an
embodiment of the present invention for introducing a liquid
into a packed bed;
Figure 2 is a top plane view of the embodiment of
~igure l;
Figure 3 is a partial sectional view of an embodiment
of the present invention for introducing a gas into a packed bed;
i ~.0639:~7
Figure 4 is a top plane view of the embodiment of
Figure 3; and
Figure 5 is a simplified schematic representation of
a packed bed incorporating the gas feed embodiment of Pigure 3 and
the liquid feed embodiment of Figure 1.
; Referring now to Figures 1 and 2 of the drawings
which illustrate an embodiment of the liquid distributor of the
present invention, a vessel 10 is provided with suitable packing,
schematically illustrated as 12. The upper portion of the vessel
lO is provided with a liquid feed inlet 13 for introducing liquid
feed into the vessel 10 for distribution thereof into the packing
through the liquid distributing apparatus of the present invention. .
The liquid distributing apparatus of the present
invention, generally indicated as 14, is comprised, in its ma;or
parts, of a main distributor box 15, positioned in the packing
. in a plane below the plane on which the liquid feed inlet 13 is
; located; and a plurality of branch distributor boxes 16, positioned
on a plane below the plane of the main distributor box 15. As
particularly shown, the main distributor box 15 is centrally
positioned in the vessel 10 and the plurality of branch distributor
boxes 16 are circularly arranged about the main distributor box
15, but it is to be understood that other arrangements may also
be employed. The main distributor box 15 and the plurality of
branch distributor boxes 16 are positioned within and are supported
by the packing and, accordingly, there is no need for separate
- and independent support structure for the boxes 15 and 16. The
main distributor box 15, and each of the branch distributing boxes
16, are provided with means for distributing liquid from the boxes
into the bed. As particularly shown, such means is in the form .
of a plurality of perforations or orifices 17 in the bottoms
~0~39~7
of box 15, and a plurality of perforatlons or orlfices 18 in the
bottom of boxes 16, but it is to be understood, that other means,
such as, notched weirs, etc. may be employed instead of perforations.
The upper portion of main box 15 is preferably provided with a
notched weir 19 to accommodate for overflow or liquid surge, and
the branch distributor boxes 16 are also preferably provided with
notched weirs 21 for the same purpose.
A main spillway 22 is positioned within and supported
by the packing 12 between the liquid inlet 13 and the main dis-
tributor 15 for receiving liquid introduced through the inlet 13and transporting same to the main distributor box 15. The main
spillway 22 is supported on a packing level above the packing
level which supports the main distributor box 15, and as particu-
larly shown, is provided with a downwardly inclined interior
surface 23 on which the liquid is transported from the main
spillway inlet 24, positioned ad;acent to the liquid feed inlet
13, to the main spillway outlet 25, positioned above and in
fluid flow communication with main distributor box 15. The main
spillway 22 is also provided with suitable vent orifices 26
and drain orifices 27.
A main liquid deflector 31 is positioned within and
supported by the packing 12, at a packing level above the packing
level supporting main spillway 22, directly opposite liquid
inlet 13, to insure that the liquid introduced through the feed
inlet 13 is directed into the main spillway 22.
A plurality of branch spillways 32 (one for each
branch distributor box 16) are positioned within and supported
by the packing 12, between each branch distributor box 16 and
the main distributor box 15, for receiving liquid from the
=a-n dlstribut~r box and transportlng same to the branch
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', '.
~0~3927
distributor boxes. The branch spillways 32 are supported on a
packing level below the packing level which æupports the main
distributor box lS, and above the packing level which supports
the branch distributor boxes 16. The inlet portion 33 of the
branch spillways 32 are positioned below and around the outer
perimeter of the orifices 17 of the main distributor box 15
whereby one portion of the liquid introduced into the main
distributor box 15 is distributed through the outer portion of the
orifices 17 to the branch spillways 32, and a further portion of
the liquid is distributed through the central portion of the
orifices 17 into the bed packing. As particularly shown, the
branch spillways 32 are provided with a downwardly inclined inter-
ior surface 34 on which liquid is transported to the outlet portion
35 of the spillways 32 for introduction into the branch distributor
boxes 16. The branch spillways 32 are also provided with suitable
drain orifices, generally indicated as 36.
In operation, liquid feed introduced through inlet
13 is passed through main spillway 22 to the main distributor box
16. The liquid introduced into the main distributor box 16 is
distributed, through orifices 17, to the bed packing and the
branch spillways 32. The liquid introduced into branch spillways
32 is passed to the branch distributor boxes 16 and distributed,
through orifices 18, to the bed packing. As particularly shown,
the liquid distributing system 14 is comprised of eight branch
distributor boxes and one main distributor box, with about
50% of the liquid introduced into the main distributor box 15
belng distributed to the branch spillways for distribution
to the packing through the branch distributor boxes 16,
1063927
and about 50% of the liquid being introduced into the center of
the packing through the main distributor box 15. It is to be
understood, however, that other arrangements are possible within
the spirit and scope of the invention.
As should be apparent from the hereinabove description,
the liquid distributing system is structurally independent of the
vessel wall in that the system is supported in and by the bed
packing. The number of branches, dimension of components, etc.
is a function of bed si7e, packing characteristics, maximum and
minimum flow quantities, properties of the liquid, etc. and the
design of such components is well within the scope of those skilled
in the art from the teachings herein. Similarly, the packing
may shift within normal expectations causing some tilting of the
components of the distributing system and such tilting may be
compensated for by selection of the slope of the spillways and
liquid head over perforations or weirs. ~-
The invention will now be further described with
respect to Figures 3 and 4 of the drawings which illustrate a ~ -
preferred embodiment of a distributor of the present invention
for distributing a gas to a packed bed.
Referring now to Figure 3 and 4, a vessel 100 is -~
provided with suitable process packing 101 and a gas feed inlet
102 for introducing gas into the gas distributor of the present
invention, generally indicated as 103, positioned within and
supported by the process packing 101. -
The gas distributor 103 is comprised of a gas plenum
chamber 104, within the interior of the process packing, and a
plurality of pillars 105, in the form of hollow pipe sections,
which includes means as hereinafter described for distributing
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~063927
gas into the process packing above plenum chamber 104.
As particularly shown, a plurality of the pillars
105 are supported within and by the process packing in a con-
tiguous relationship to define an outer perimetric wall 114 of
the plenum chamber 104. A further portion of the pillars 105
are centrally positioned within and supported by the process
packing to provide means for distributing gas into the central
portion of the process packing above plenum chamber 104. As
particularly shown, the centrally positioned pillars 105 are
positioned in a contiguous relationship to define an inner
perimetric wall 115 of the plenum chamber 104, with the voids
between the central pillars being filled with a packing 116
preferential for a liquid. Similarly, the voids between the outer
pillars 105 and the wall of vessel 100 are filled with a packing
117 preferential for a gas.
The plenum chamber 104 is open at its bottoms
whereby the process packing defines the floor of the plenum
chamber and is closed at its top by a roof, defined by a plurality
of roof slabs 106, supported between the pillars 105. Accordingly,
gas introduced into plenum chamber 104, through gas inlet 102,
can not directly flow from the plenum chamber 104 into the
process packing above plenum chamber 104.
The interior of the pillars 105 include means for
passing and distributing gas into the processing packing, above
the plenum chamber 104, in the form of risers 107, concentrically
positioned within and spaced from the walls of the pillars 105.
It is to be understood that other means, such as packing
preferential to a gas can be used for effecting such distribution.
10639Z7
It is to be understood that the risers 107 function
to distribute gas which flows out of the bottom of plenum chamber
104 into the packing above the plenum chamber. In the case,
where the gas distributor is employed as an intermediate gas feed,
the gas passing through the packing below the plenum chamber is
also distributed through risers 107 into the packing above the
plenum chamber. The interior of the pillars 105 further include
means for distributing liquid from the packing above the plenum
chamber into the packing below the plenum chamber, in the form
of packing 108 preferential for liquid, positioned between the
risers 107 and the walls of the pillars 105.
In operation, gas feed is introduced into plenum
chamber 104 through gas inlet 102 and flows out of the open
bottoms thereof. The gas feed then flows through the risers 107
and packing preferential for a gas 117 along with any gas from
the packing below the plenum chamber, into the process packing
above the plenum chamber. The liquid from the packing above the
plenum chamber flows through the packing 108, preferential for - -
liquid into the packing below the plenum chamber.
As should be apparent from the hereinabove des-
cription, the gas distributor of the present invention is comprised
of a gas plenum chamber within the packing, and means for dis-
tributing the gas from the gas plenum chamber into the packing
above the plenum chamber which is supported within and by the
,. process packing, whereby the gas distributor is structurally
independent of the vessel wall. The design of the various
components to achieve the required capaclty and gas paths is
within the s~ope of those skilled in the art from the teachings
herein
~0~39Z7
Referring to Figure 5 of the drawings, there ls shown
a packed bed containing a liquid feed distributor according to
the present invention designated as 201, and gas feed distribu-
tors, according to the present invention, designated as 202
for introducing gas feed at both an intermediate and lower
portion of the packed bed. The vapor is withdrawn from the
packed bed through vapor outlet 203 and the liquid is withdrawn
from the bed through liquid outlet 204.
The present invention is particularly advantageous
in that liquid and/or gas can be introduced into a packed bed
contacting apparatus through distributors which are structurally
independent of the vessel wall. This results in a savings
with respect to structural cost and vessel height. In addition,
the components may be constructed of materials suitable for the
conditions and/or materials employed in the bed. The present
invention achieves such results, in part, by departing from
the previously accepted principle that distributing parts must
be in a single horizontal plane and by structurally supporting
the various component parts within and by the packed bed.
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