Dual phase distribution device

A device is provided for mixing two fluids, one a liquid, the other a gas, where apertures are provided in channel tubes to mix the fluids in the individual channels. The mixing device provides a two fluid admixture for passage to downstream processing, most preferably the tubeside of a shell and tube heat exchanger. The vessel is equipped with a gas inlet means located below a liquid inlet means with respect to the height of the vertical vessel. A distributor plate is situated substantially perpendicular to said channel or channels at a point in said vessel below said apertures for influx of the liquid into the gas phase. The apparatus provides uniform distribution of gas and liquid to all parallel channels.

FIELD OF THE INVENTION 
This invention is concerned with a uniform distribution and mixing 
apparatus to mix two distinct phases, one a liquid and the other a gas. 
These types of devices have historically been important in passing a dual 
phase mixtures to heat exchangers in many industries including the 
chemical and oil refining industries. 
BACKGROUND OF THE INVENTION 
A multistage reactor including a vertical column is disclosed in U.S. Pat. 
No. 3,642,452 (Tarbourich). A bundle of vertical tubes serve the ascent 
and descent of liquid. Pipes arranged in coaxial relation with respect to 
said tubes carry gas and a down tube is provided for better mixing of the 
phases. 
Many prior art patents have discussed many means to mix two phases. In U.S. 
Pat. No. 3,452,966 (Smolski) liquid such as water is mixed with air via an 
open-ended vertical tube. The lower end of the tube is submerged in the 
liquid above a gas bubble generator. A helical baffle is provided to 
create a turbulence in the tube and assist in adsorption of the gas into 
the liquid. 
In U.S. Pat. No. 3,738,353 (Santoleri) a series of sparger tubes are 
mounted below a heat exchanger within the confines of a baffle plate. Air 
bubbles are discharged upward which increases the transfer of heat from a 
waste-water stream. In U.S. Pat. No. 4,440,698 (Bloomer), a heat exchanger 
is provided whereby jets are created in the duct through which the gas 
flows which contacts the exchanger. Liquid is sprayed over the heat 
exchanger and high velocity jets of gas pick up liquid and carry it into 
the exchanger. 
Finally, U.S. Pat. No. 5,376,311 (DeGuzman) discloses an apparatus for the 
aeration of liquids by passage of a gas through a porous diffuser thereby 
producing microsized bubbles dispersed in the liquid. A porous tubular 
member is provided in approximately the center of the apparatus. 
BRIEF DESCRIPTION OF THE INVENTION 
This invention is an apparatus for uniform distribution and mixing two 
phases together using a partitioned vessel having means for the inlet of 
gas and liquid to the vessel. Liquid enters the vessel, which is vertical 
in orientation, at a point in elevation higher than the gas inlet. The 
liquid and gas mix in the channels or tubes which are vertically 
orientated in the vessel, through an aperture in tubes for the ingress of 
liquid to the gas stream moving through the channels or tubes. It is 
preferred but not required that the vessel communicate with the tubeside 
of a shell and tube heat exchanger. 
DETAILED DESCRIPTION OF THE INVENTION 
In heat exchangers, the disproportionate flows and improper mix of vapors 
and liquid greatly affects performance. An improper mixture of gas and 
liquid in a heat exchanger has a negative influence on refinery 
operations. Tubes that become deficient in liquid tend to dry out and 
foul, which leads to a reduction in heat transfer rates. It also adds 
greatly to maintenance tasks. 
In addition, conventional distributors can produce a relatively non-uniform 
distribution of liquid and thus are more sensitive to minor variations in 
heat exchanger orientation. Good liquid and gas distribution is 
particularly important where relatively small temperature differences 
exist between the hot and cold streams that exchange heat with each other 
in the heat exchanger. 
This invention acts to insure uniform admixture of gas and liquid. This 
invention establishes a mixed stream that can be used in the tubeside of 
shell and tube heat exchangers. Instead of premixing liquid and gas in a 
single plenum below the exchanger and, then passing that admixture through 
a perforated plate, the apparatus described herein mixes the gas and 
liquid through apertures in vertically orientated channels or tubes. 
The apparatus herein described is situated in a vertical orientation with 
respect to the horizon. The vessel is partitioned on the inside and has 
side walls, a bottom and a top. A gas inlet is provided at the bottom of 
the vessel. Gas may enter directly into the vessel, or as a preferred 
embodiment, the gas may accumulate in a plenum chamber having a solid 
plate defining the top of the plenum chamber interrupted only with 
apertures for the passage therefrom of the gas through one or more 
vertical tubes. 
A liquid inlet means is also provided which is preferably located in 
elevated position with respect to the gas inlet and, if existent, the 
plenum chamber. The liquid inlet permits liquids, such as treated water or 
hydrocarbon liquids, to enter the vessel and be confined therein between 
the top of the plenum chamber (bottom) and the top part of the vessel. It 
is desirable that the liquid level be maintained at a level lower than the 
top of the vessel. The liquid level must however be maintained above the 
elevation of perforations or apertures in the channels wherein gas is 
being passed from the plenum chamber. 
In a preferred embodiment of this invention, a liquid distribution plate 
may be situated above the top of the plenum chamber and below the level of 
the apertures in the tubes. The plate is equipped with multiple 
selectively sized and situated perforations or apertures to provide a 
uniform liquid level in the vessel at a point above the liquid 
distribution plate. 
A hollow channel, or multiple channels, are provided for the passage of gas 
which mixes with the liquid. These channels are also referred to herein as 
tubes and will preferably have a circular cross section. However, any 
other cross-section can also be used such a square, rectangle or triangle. 
These tubes interconnect and communicate with the gas inlet or plenum 
chamber. Each tube contains one or more apertures to admix the gas with 
the liquid. As set forth above, the liquid level must be above the 
aperture height in order for the liquid to enter the tube to mix with the 
gas. The aperture or apertures may have any cross-section although 
circular apertures are preferred for manufacturing purposes. While not a 
preferred embodiment herein, the apertures on the tubes may be arranged at 
different heights and it is possible to have multiple apertures at 
different heights on the same tube. 
The top of the vessel is constructed so that the mixture of gas and liquid 
pass from the vessel to use downstream in a different vessel or 
environment. The structure of FIGS. 4-6 discussed herein show preferred 
embodiments concerning passage downstream to other uses but this invention 
should not be limited to those specific preferred embodiments. And, as 
shown in FIG. 2, the channel tubes may actually penetrate the bottom of a 
shell and tube heat exchanger with the gas-liquid mixture in the tubes 
being used to indirectly cool or heat a liquid or a gas in an exchanger. 
In this embodiment, the used gas-liquid admixture exits the heat exchanger 
through an outlet means in the top of the exchanger.

DETAILED DESCRIPTION OF THE DRAWINGS 
In FIG. 1 a vertical vessel 1 is shown with the necessary elements that 
comprise this invention although other additional elements that are not 
integral to the function of the mixing of the two phases are not shown. 
The vertical vessel is partitioned to accomplish the mixing of the two 
phases. The vessel comprises side walls 3, bottom 5 and top 7. The bottom 
of the vessel 5 communicates with a gas inlet 9 for the flow of gas into 
the vessel. In a preferred embodiment, gas inlet 9 communicates with the 
interior of the vessel through a plenum chamber 11 having a top plate 13 
which extends from each side wall 3. The gas chamber is designed to 
provide uniform flow of gas to all tubes 15. Top plate 13 is imperforate 
with the exception of at least one, and preferably more, tubes 15 openly 
communicate with the plenum chamber and the upper portion of the vessel. 
Thus, gas rises from the inlet means 9, to the plenum chamber 11 and then 
through tubes 15 for eventual admixture with a liquid phase. 
Tubes 15 may be any length as long as they extend to a point above the 
level of liquid 17 which may vary in different vessels which are used for 
mixing different phases. As a corollary, an open space 19 of varying 
height is provided intermediate the liquid level 17 and the vessel top 7. 
A liquid inlet is provided in the vessel for the flow of liquid into the 
vessel which is to be mixed with the gas in tubes 15. The liquid is 
segregated from plenum chamber 11 and is situated in the vessel at an 
elevated height with respect to either plenum chamber 11 or gas inlet 9 
via imperforate plate 13 and tubes 15 which seal the apertures in the 
otherwise solid plate 13. Liquid passes into vessel 1 to form a liquid 
reservoir 21 having a level shown at 17. In a preferred embodiment, the 
liquid is evenly distributed to the vessel interior via a liquid 
distribution plate 23 having select predetermined perforations therein for 
the controlled passage of liquid to liquid reservoir 21. Distribution 
plate 23 must be positioned above (or higher than) liquid inlet 19. 
Gas passes upwardly through tubes 15 and mixes with liquid entering via 
apertures 25 situated in tubes 15. Apertures 25 in tubes 15 are located in 
the tubes at a height above liquid distribution plate 23 and below the 
level of liquid 17 in vessel 1. The apertures 25 may comprise any number 
of openings in the form of a large number of pin hole openings to one 
opening specifically sized to enhance the mixing of the two phases. Liquid 
passes from the liquid reservoir to the interior of tubes 15 via apertures 
25. In this manner, the two phases are admixed immediately upstream of use 
in a vessel, such as a heat exchanger in another vessel surmounted to 
vessel 1. 
FIG. 2 shows a shell and tube heat exchanger 101 which is situated 
immediately above mixing vessel 1. The top 7 of vessel 1 forms the bottom 
of heat exchanger 101. Top 7 is imperforate with the exception of openings 
for passage of tubes 15 into the exchanger. The connection of the tubes 
with top 7 are sealed on the top and bottom of top 7 via any conventional 
means such as welding. Exchanger 101 is equipped with inlet means 103 and 
outlet means 105 for the passage of shellside fluid into and out of the 
exchanger. The fluid entering the exchanger indirectly contacts the mixed 
phases from vessel 1 via tubes 15 and thereby either cools or heats the 
fluid to the desired level of temperature. The mixed phase of fluids 
passing through tubes 15 in vessel 101 exits the exchanger through outlet 
means 107 which communicates with a collection space 109 which does not 
communicate with the shellside fluid that is being cooled or heated in 
exchanger 101. 
FIG. 3 shows a cross section of vessel 1 wherein tubes 15 rise above 
distribution plate 23 and liquid is supplied to the liquid reservoir 21 
via perforations 27 in plate 23. 
FIG. 4 is a side view of the upper portion of vessel 1 and the lower 
portion of vessel 101. This configuration is a preferred means of passing 
the mixed phases to a surmounted heat exchanger. Tubes 15 penetrate top 
plate 7 thereby passing the mixed phase from vessel 1 to vessel 101 for 
use therein however, the area above and below plate 7 do not communicate 
with one another. 
FIG. 5 shows via a side view, tubes 15 ending or terminating immediately 
below top plate 7. A second set of tubes 15A is positioned above and 
juxtaposed to the terminus of tube 15 for passage of a gas/liquid 
admixture from tube 15 directly into tubes 15A, located in vessel 101. 
FIG. 6, via a side view, shows another configuration whereby tubes 15A 
from vessel 101 penetrate the top 7 of vessel 101. The bottom of tubes 15A 
are equipped with with flared inlet, 201. These flares may extend from the 
ends of tube 15A or from plate 7. If a line is drawn of the angle that 
flare 201 makes with the plate, that angle is less than 90.degree..