Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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TITLE: High Velocity Low Impact Liquid Feed Distributor
BACKGROUND OF THE INVENTION
(1) Field of the Invention
[0001 ] This invention concerns liquid feed distributors that are capable of
distributing a high velocity feed with a corresponding low pressure drop with
little to
no fouling.
(2) Description of the Prior Art
[0002] Introducing a liquid feed uniformly into a liquid filled vessel such as
a
contactor can be difficult. Often, distributors with complex distribution
piping are
to used to uniformly distribute a liquid feed across a cross section of a
vessel.
Currently available distributors generally include primary and secondary
distribution
arms or manifolds. One or both of the primary and secondary distribution arms
will
typically include a multitude of small holes through which a liquid feed flows
into a
vessel. As a result of the number of distribution arms and the multitude of
small
holes, the pressure drop across the distributor -- as the liquid feed flows
through the
distributor into the vessel - is very low. This correlates to a low velocity
for the liquid
flowing through the distributor distribution arms and small holes.
[0003] Low liquid velocities in the distribution arms can lead to distributor
fouling in
certain applications. For example, where solids are suspended in or formed in
the
liquid feed, the solids can foul the distribution arms and/or small holes
because the
liquid feed velocity is not great enough to prevent the solid materials from
blocking or
plugging the arms and holes. This in turn can result in non-uniform liquid
distribution. There is a need, therefore, for liquid distributors that
distribute liquids at
higher velocities and/or that do not include structures or features that are
prone to
fouling and plugging. Moreover, there is a need for new distributors that
introduce
one or more immiscible liquids into a vessel.
SUMMARY OF THE INVENTION
[0004] The present invention solves one or more of the problems with prior art
liquid
distributors by providing a device that allows liquids to be introduced into a
vessel at
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high velocities. The devices of this invention include features that quickly
distribute
the introduced high velocity liquid throughout a vessel while simultaneously
reducing
the velocity of introduced liquid.
[0005] One aspect of this invention are liquid distribution devices
comprising: a
liquid distributor including an inlet pipe, and a piping manifold connected to
a first
end of the inlet pipe wherein the piping manifold includes a plurality of
liquid
distribution pipes each liquid distribution pipe including an inlet connected
to the
piping manifold and an outlet; and an impact portion comprising a plurality of
pans,
each pan having a top surface wherein at least one pan top surface is oriented
io essentially perpendicular to the direction of liquid exiting the outlet of
at least one of
the plurality of liquid distribution pipes.
[0006] Another aspect of this invention are liquid distribution devices
comprising: a
liquid distributor including an inlet pipe and a piping manifold connected to
the inlet
pipe wherein the piping manifold includes a plurality of liquid distribution
pipes each
liquid distribution pipe including an inlet connected to the piping manifold
and a
downwardly oriented outlet wherein outlets distribution pipe are essentially
co-
planar; and an impact portion that includes a plurality of pans having
essentially co-
planar and circular top surfaces wherein each of the plurality of pans is
associated
with a different liquid distribution pipe outlet, wherein each pan top surface
is
essentially perpendicular to the direction of liquid exiting each liquid
distribution pipe
outlet.
[0007] Yet another aspect of this invention are methods for distributing
liquid in a
vessel comprising; installing in a vessel a liquid distribution device
including an inlet
pipe, and a piping manifold connected to a first end of the inlet pipe wherein
the
piping manifold includes a plurality of liquid distribution pipes each liquid
distribution
pipe including an inlet connected to the piping manifold and an outlet, and an
impact
portion comprising a plurality of pans each pan having a top surface wherein
at least
one pan top surface is essentially perpendicular to the direction of liquid
exiting the
outlet of one or more of the plurality of liquid distribution pipes; directing
liquid
through the inlet pipe into the piping manifold in an amount sufficient to
product a
liquid velocity at the outlet of each of the plurality of liquid distribution
pipes ranging
from 1.2 to 7.5 M/sec.; and directing the liquid flowing from the outlet of
each of the
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plurality of liquid distribution pipes at the top surface of at least one pan
such that at
least a portion of the directed liquid flows is redirected radially away from
the center
of the pan and wherein the velocity of the liquid flowing radially away from
the center
of the pan and measured at the perimeter of the pan is no more than 1.5
M/second.
DESCRIPTION OF THE FIGURES
10008] Figure 1 is side view of a liquid distributor embodiment of this
invention
including a liquid distributor (10) and an impact portion (30);
[0009] Figure 2 is a bottom view looking up at impact portion (30) of a liquid
distributor embodiment of this invention;
[0010] Figures 3A and 3B are side and top views of one possible pan embodiment
of this invention; and
[00011] Figure 4 is a side view showing examples of relationships between
distributors and pans associated with liquid distribution devices of this
invention.
DETAILED DESCRIPTION OF THE INVENTION
[0012] The present invention is directed to liquid distribution devices that
are useful
for quickly directing liquids moving at high initial velocities into liquid
containing
vessels and thereafter quickly reducing the velocity of the introduced liquid
to
uniformly distribute the introduced liquid in the vessel. Unlike liquid
distributors of
the prior art, the liquid distribution devices of this invention do not
include small
orifices. Therefore, the present invention solves at least some of the
problems
associated with distributing liquids at low velocity through a multitude of
small
orifices. The liquid distribution devices of this invention solve some of the
prior art
distribution problems because they include a plurality of liquid distribution
pipes that
direct liquids at high velocities towards opposing pans. When the high
velocity liquid
exiting the distribution pipe outlets impacts the pans, the liquid flow is
redirected and
further distributed causing a substantial reduction in the velocity of the
liquid as it
flows off of the pan(s).
[00013] The liquid distribution devices of this invention will now be
described with
reference to Figures 1-4. The liquid distribution devices of this invention
comprise
two primary elements. The first primary element is a liquid distributor 10 and
the
second primary element is a liquid impact portion 30. Liquid distributor 10
and liquid
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impact portion 30 may be connected to each other to form a single liquid
distribution
device structure that is located in a vessel. Alternatively, liquid
distributor 10 and
impact portion 30 may be independently associated with a vessel in a manner
that
causes them to be oriented as described below.
[0014] Referring now to Figure 1, liquid distributor 10 includes an inlet pipe
12
having a first end 14 that is associated with piping manifold 16. The opposing
second end of inlet pipe 12 (not shown) will be associated with a liquid feed
source
such as a pump that is associated with a liquid filled feed tank, with a
liquid feed
source, etc. Piping manifold 16 includes a plurality of liquid distribution
pipes 18.
Each liquid distribution pipe 18 includes an inlet 20 that is associated with
piping
manifold 16 and an open outlet 22.
[0015] Liquid distribution pipes 18 and their corresponding outlets 22 may be
associated with piping manifold 16 in any number and in any orientation that
will
efficiently distribute liquid in a vessel. The number of liquid distribution
pipes 18
used will vary depending upon a variety of factors including but not limited
to the
liquid vessel cross-sectional area, the design liquid feed rate and the
desired feed
velocity exiting outlets 22.
[0016] The piping manifold 16 and distribution pipes 18 will generally be
associated
with manifold 16 and have lengths and internal dimensions to ensure, as much
as
practical, that essentially the same volume liquid at essentially the same
velocity
exits the outlet 22 of each liquid distribution pipe 10. Generally, the
velocity of liquid
exiting outlet 22 will range from 1.2 to 7.5 M/sec, more preferably from 2.0
to 6.0
M/sec. and most preferably from 3.5 to 5.0 M/sec. However, in some instances
it
might be beneficial to design distributor 10 such that pipes 18 distribute
different
volumes of liquids and/or deliver liquids at different velocities to different
vessel
locations.
[0017] The velocity of the liquid exiting outlets 22 of liquid distribution
pipes 18 must
be reduced in order to ensure uniform liquid feed distribution in the vessel.
Impact
portion 30 provides the liquid velocity reducing elements. An impact portion
30 of
liquid distribution devices of this invention is shown in Figure 1. Impact
portion 30
includes a plurality of pans 32 where each pan includes a top surface 34 and a
bottom surface 36. The pan top surface 34 will preferably have an area that is
large
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enough to reduce the velocity of liquid exiting outlet 22 that impinges upon
pan 32.
In one embodiment the pan reduces the velocity of the liquid flowing laterally
at edge
33 of pan 32 to no more than 1.5 M/sec, preferably no more than 0.6 M/sec. and
most preferably no more than 0.25 M/sec. Generally, each pan 32 will have
cross
sectional area that is from 4 to 200 times the cross sectional area of a
corresponding
liquid distribution pipe outlet or outlets 22. For example, in a typical
vessel, outlets
22 will have circular openings having a diameter of from 2 cm to 6 cm or more.
The
pans 32 will be circular with diameters of 30 cm to 50 cm.
[0018] Pan 32 may be any shape capable of reducing the velocity of liquid
exiting
outlet 22 to a desired rate including but not limited to shapes such as
circular,
square, a star, rectangle and amorphous shaped. It is preferred, however, that
pan
32 is circular in shape. Moreover, it is preferred that outlet 22 of a liquid
distribution
pipe is orientated at pan top surface such that the liquid emerging from
outlet 22
impacts pan top surface 34 at essentially the center 35 of pan top surface 34.
In
most instances this will mean that outlets 22 will be oriented with respect to
pans 32
such that the liquid flowing out of outlet 22 impacts pan top surface 34
perpendicularly. The combination of a pan circular shape and directing liquid
emerging from outlet 22 at the center of the circular pan top surface 34
causes the
liquid to change flow direction by most 90 and be distributed volume-wise
essentially uniformly across the pan top surface 34. The combination further
facilitates the efficient drop in the liquid velocity of the liquid exiting
outlet 22. As
liquid flows from outlet 22 impacts top surface 34 of pan 32, the liquid flow
is
redirected so that it flows parallel to pan top 34. Initially, the horizontal
velocity is
proportional to the radius of outlet 22. As the liquid that flows across pan
top
surface 34, the liquid horizontal velocity decreases. These distances that the
liquid
flows over the top of the pan to surface 34 will preferably be great enough so
that
the liquid velocity drops from 1.2 to 7.5 M/sec at outlet 22 to from 0.25 to
1.5 M/sec.
at the pan perimeter. Moreover, these dimensions will generally reduce the
liquid
velocity uniformly as the liquid passes across the pan top surface 34 meaning
that
the velocity of liquid at any point around edge 33 of pan 32 will be
essentially
equivalent and/or will fall below the liquid velocities at the pan perimeter
recited
above.
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[0019] it is contemplated that a single pan 32 can be associated with more
than one
liquid distribution pipe outlet 22. For example, two liquid distribution pipe
outlets 22
can be associated with a single pan 32 having a top surface shaped like a
figure-
eight. In this embodiment, each outlet 22 would be centered over one of the
circular
portions of the figure-eight. It is preferred however that each liquid
distribution pipe
outlet 22 be associated with a corresponding pan 32. This way, every outlet 22
can
be located, as much as possible, over the center of the pan top surface 34
towards
which it is directed and it minimizes interaction between liquid streams
exiting
different distribution outlets 22.
to [0020] When installed in a vessel as shown in Figure 1, pans 32 will
preferably be
oriented such that each pan top surface 34 is perpendicular to the direction
of the
flow of liquid exiting each outlet 22 of liquid distribution pipes 18. Since
the liquid
exits liquid distribution pipes 18 at high velocities, the liquid will impinge
against pan
top surface 34 at a high velocity which will change the direction of the
liquid and
is cause it to flow laterally towards edge 33 of pans 32 in all lateral
directions thereby
distributing the liquid evenly throughout the vessel.
[0021] The distance H between an outlet 22 of a distribution pipe 18 and a top
surface 34 of pan 32 may vary. H should be a distance that allows essentially
all of
the liquid passing through outlet 22 to impinge against pan top surface 34 and
it also
20 should be at a distance that, in conjunction with the pan dimensions,
causes the
liquid flowing off the pan perimeter to be at the desired liquid flow velocity
and
preferably from 0.25 to 1.5 M/sec. at the pan perimeter. For example H may
range
from 5 cm to 60 cm or more.
[0022] The distance H may be the same for all distribution pipes and pans in a
liquid
25 distribution device or some heights H may be the same and some different or
all of
the heights H may be different for different outlet/pan combinations. This
aspect of
the invention is shown in Figure 4 which includes a horizontal piping manifold
16
having a plurality of liquid distribution pipes 18. In Figure 4, the liquid
distribution
pipe outlets 22 are not all coplanar. However, in a preferred embodiment, the
30 outlets 22 will be coplanar. Additionally, the top surface 34 of each pan
32 is also
not coplanar in Figure 4. However, in a preferred embodiment, the top surface
of
pans 32 will all be essentially coplanar with respect to one another. Finally,
in Figure
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4, the distances H between outlet 22 and pans 32 vary. However when outlet 22
and pans 32 are both essentially coplanar, distance H will be essentially the
same
for all outlet/pan pairs.
[0023] Pan top surface 34 may include a particle and/or velocity reducing
surface
that promotes the reduction of the size of any particles in the vessel or in
the liquid
exiting liquid distribution pipe outlets 22. However, any pan top surface
features that
might facilitate particle size reduction may also facilitate unwanted
deposition of
particles on the pan surface. Therefore, it is generally preferred that the
pan top
surface is smooth.
to [0024] Pan top surface 34 may include ridges 41 that are notched or
serrated so
that they are useful for controlling the level of liquid on the pan 30. A
preferred ridge
41 is serrated as shown in Figures 3A and 3B. In Figures 3A-3B, the serrated
ridges
41 are radial spaced apart serrations that originate at the center of pan top
surface
34 and that radiate end at pan perimeter 33. The distance between the peaks 37
and valleys 39 of serrations is not especially critical. However, useful
serrations will
generally have a distance between a peak 37 and a valley 39 of from 1 cm to 5
cm.
[0025] One example of a vessel cross section having a plurality of pans 30 is
shown
in Figure 2. The cross section shown in Figure 2 includes a center pan 32A and
a
plurality of peripheral pans 32B. Peripheral pans 32B may be oriented with
respect
with center pan 32A in any manner that allows flowing from distributor pipe
outlets to
be evenly distributed in the vessel. In one embodiment, pans 32B will be
orientated
in a spoke-type pattern with respect to center pan 32A. In this embodiment,
each
peripheral pan 32B is separated from its adjacent peripheral pan 32B by an
angle a
where the angle a is generally the same for each pair of adjacent peripheral
pans
32B. It should be noted however, that the angle a need not be the same and may
be different for one to all of the adjacent peripheral pans 32B.
[0026] the term "essentially" is used herein to modify certain terms. As the
term
"essentially" takes into consideration that there may be some variance from
the
desired orientation, length, plan, center, etc... due to, for example, device
construction and installation factors.
[0027] Figure 1 is an embodiment of a liquid distributor of this invention
installed in
a vessel 50. Vessel 50 includes a wail 51 having an outside surface 54 and an
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inside surface 56. Gusset plates 60 support pans 32 or in the alternative
gusset
plates 60 support horizontal beams 66 which in turn support pans 32. Gusset
plates
60 thereby secure impact portion 30 in place during vessel operation. In the
embodiment shown in Figure 1, vertical support beams 67 associated with pan
support beams 66 retain one or more of liquid distribution pipes 18 or
manifold 16 in
place in vessel 50. The methods for supporting and retaining liquid
distributor 10
and liquid impact portion 30 in place in a vessel shown in Figure 1 are just
examples
of methods for securing vessel intervals in place. Any other methods known to
one
of ordinary skill in the art for securing distributors or other internals in
place in a
vessel during operation may be employed in this invention.
[0028] Figure 1 shows an orientation of liquid distributor 10 with respect to
liquid
impact portion 30 whereby the liquid distribution pipe outlets are downwardly
orientated and whereby pans 30 are orientated horizontally underneath outlets
22 of
liquid distribution pipe 18. Any other pan/outlet orientation that is useful
in
distributing liquid fed into a vessel may be used. For example, the liquid
distribution
pipe outlets 22 may be upwardly oriented towards horizontal pans 32.
Alternatively,
the outlets 22 may be oriented at an angle with respect to vessel. The
important
feature of any orientation of liquid distributor 10 with respect to impact
portion is that
pans 32 should always be oriented such that pan surface 34 is essentially
perpendicular to the flow of liquid exiting liquid distribution pipe outlets
22.
