WO2010065166A2

WO2010065166A2 - High velocity low impact liquid feed distributor

Info

Publication number: WO2010065166A2
Application number: PCT/US2009/050091
Authority: WO
Inventors: Mark Van Wees; Joseph M. Slaughter; Brian W. Hedrick; Brian H. Johnson
Original assignee: Uop Llc
Priority date: 2008-11-25
Filing date: 2009-07-09
Publication date: 2010-06-10
Also published as: WO2010065166A3; US20100126621A1; BRPI0921558A2; JP2012509759A; EP2349909A2; RU2011126182A; AU2009322917A1; CN102224099A; CA2740647A1

Abstract

A liquid distribution device including a liquid distributor having an inlet pipe connected to a piping manifold that further includes a plurality of liquid distribution pipes each liquid distribution pipe including an inlet connected to the piping manifold and an outlet, and a liquid impact portion having a plurality of pans located in close proximity to the outlet of one or more of the liquid distribution pipes.

Description

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 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 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 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 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

[0008] Figure 1 is side view of a liquid distributor embodiment of this invention inciuding 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 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 wil! 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 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. [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. [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 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 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 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 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 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. [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 α where the angle α is generally the same for each pair of adjacent peripheral pans 32B. It should be noted however, that the angle α 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 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.

Claims

CLAIMS:

1. A liquid distribution device 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 essentially perpendicular to the direction of liquid exiting the outlet of at least one of the plurality of liquid distribution pipes.

2. The liquid distribution device of claim 1 wherein a different pan is associated with each liquid distribution pipe outlet.

3. The liquid distribution device of claim 2 wherein each pan top surface is circular and wherein each liquid outlet directs liquid at essentially the center of each circular pan top surface.

4. The liquid distribution device of claim 1 wherein the distance from the each liquid distributor outlet to each pan top surface ranges from 5 cm to 60 cm,

5. The liquid distribution device of claim 1 wherein the surface area of the pan top surface is from 4 to 200 times the area of the associated liquid distribution pipe outlet.

6. The liquid distribution device of claim 1 wherein the at least one pan top surface includes two or more radial ridges.

7. The liquid distribution device of claim 6 wherein at least one of the radial ridges is serrated.

8. The liquid distribution device of claim 1 wherein the outlets of each of the plurality of liquid distribution pipes are essentially co-planar with one another and wherein each the plurality of pan top surfaces are essentially co-planar with each other.

9. A vessel having an internal space defined by walls having an internal surface and an external surface wherein the distribution device of claim 1 is located in the vessel internal space such that the liquid distributor is located heightwise above the impact portion.

10. A method for distributing liquid in a vessel comprising; installing a liquid distribution device of claim 1 inside a vessel such that the liquid distributor is located heightwise above the impact portion 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 liquid flowing from the outlet of each of the plurality of liquid distribution pipes at the top surface of at least one pan such that at least a portion of the directed liquid is redirected to flow radially away from the center of the pan wherein the velocity of the redirected 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/sec.

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