CA2232382A1 - Agitated-packed extraction column - Google Patents
Agitated-packed extraction column Download PDFInfo
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- CA2232382A1 CA2232382A1 CA002232382A CA2232382A CA2232382A1 CA 2232382 A1 CA2232382 A1 CA 2232382A1 CA 002232382 A CA002232382 A CA 002232382A CA 2232382 A CA2232382 A CA 2232382A CA 2232382 A1 CA2232382 A1 CA 2232382A1
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- liquid
- layer
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Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
- B01J19/32—Packing elements in the form of grids or built-up elements for forming a unit or module inside the apparatus for mass or heat transfer
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D11/00—Solvent extraction
- B01D11/04—Solvent extraction of solutions which are liquid
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D11/00—Solvent extraction
- B01D11/04—Solvent extraction of solutions which are liquid
- B01D11/0426—Counter-current multistage extraction towers in a vertical or sloping position
- B01D11/043—Counter-current multistage extraction towers in a vertical or sloping position with stationary contacting elements, sieve plates or loose contacting elements
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D11/00—Solvent extraction
- B01D11/04—Solvent extraction of solutions which are liquid
- B01D11/0426—Counter-current multistage extraction towers in a vertical or sloping position
- B01D11/0434—Counter-current multistage extraction towers in a vertical or sloping position comprising rotating mechanisms, e.g. mixers, rotational oscillating motion, mixing pumps
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/26—Treatment of water, waste water, or sewage by extraction
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
- B01J2219/32—Details relating to packing elements in the form of grids or built-up elements for forming a unit of module inside the apparatus for mass or heat transfer
- B01J2219/322—Basic shape of the elements
- B01J2219/32203—Sheets
- B01J2219/3221—Corrugated sheets
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
- B01J2219/32—Details relating to packing elements in the form of grids or built-up elements for forming a unit of module inside the apparatus for mass or heat transfer
- B01J2219/322—Basic shape of the elements
- B01J2219/32203—Sheets
- B01J2219/32213—Plurality of essentially parallel sheets
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
- B01J2219/32—Details relating to packing elements in the form of grids or built-up elements for forming a unit of module inside the apparatus for mass or heat transfer
- B01J2219/322—Basic shape of the elements
- B01J2219/32203—Sheets
- B01J2219/32224—Sheets characterised by the orientation of the sheet
- B01J2219/32227—Vertical orientation
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
- B01J2219/32—Details relating to packing elements in the form of grids or built-up elements for forming a unit of module inside the apparatus for mass or heat transfer
- B01J2219/322—Basic shape of the elements
- B01J2219/32203—Sheets
- B01J2219/32255—Other details of the sheets
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
- B01J2219/32—Details relating to packing elements in the form of grids or built-up elements for forming a unit of module inside the apparatus for mass or heat transfer
- B01J2219/324—Composition or microstructure of the elements
- B01J2219/32408—Metal
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
- B01J2219/32—Details relating to packing elements in the form of grids or built-up elements for forming a unit of module inside the apparatus for mass or heat transfer
- B01J2219/324—Composition or microstructure of the elements
- B01J2219/32483—Plastics
Abstract
An agitated-packed column (12) utilizing structured packing (20) of the plate variety secured in the calming sections (14) thereof. The structured packing (20) is divided into bundles of corrugations angularly oriented one to the other. Each calming section (14) has multiple layers (67, 68, 69) of structured packing (20) which are rotated relative to each other to further enhance the distribution of liquid therethrough and to effect and improve sealing along the edges thereof.
Description
AGTTAT~T~PAC~C~D ~XTRACTToN COT.UMN
R~CKGROUND OF T~ I~ V t~ ON
F;el~ of the Tnvent;Qn The present invention pertains to chemical process towers and, more particularly, to agitated extraction columns assembled with structured packing.
H;story of the Pr;or Art In the liquid-liquid contact art, it is highly desirable to utilize methods and apparatus that efficiently improve the quantity of mass transfer occurring in process towers. This is generally Wo97/10886 PCT~S96/12997 accomplished with countercurrent liquid extraction systems. Liquids of such systems flow continuously and countercurrently through one or more chambers which may have specially designed apparatus mounted therein.
Apparatus of this type may include agitators for affecting the physical properties (e.g., droplet size) of the liquid and tower packing which serves to obstruct the direct flow of the liquids. Packing also provides better contact between lighter rising liquids and heavier settling liquids, and better contact means higher efficiency.
Liquid-liquid process towers are generally constructed to provide descending heavy liquid flow from an upper portion of the tower and ascending liqht li~uid from a lower portion of the tower. It has been found desirable in the liquid-liquid contact portion of the prior art to provide apparatus and methods affording efficient mass transfer, or liquid-liquid contact, whereby contact of the fluids can be accomplished with a minimum pressure drop through a given zone of minimum ~;menqions~ High efficiency and low pressure drop are important design criteria in liquid-liquid extraction operations. Sufficient surface area for liquid-liquid contact is necessary for the primary function in the reduction or elimination of heavy liquid entrainment present in the ascending lighter liquid. Most often, it is necessary for the structured packing array in the column or in the calming zone of agitated extraction systems to have sufficient surface area in both its horizontal and vertical plane so that fractions of the heavy constituents are conducted downwardly, and the lighter liquid is permitted to rise upwardly through the packing with minimum resistance. With such apparatus, heavy and light constituents of the feed are recovered at the bottom and top of the tower, respectively.
A passive liquid-liquid tower (no mechanically induced agitation), generally includes a plurality of stacked layers affording compatible and complemental design. Such a design is set forth, shown and discussed in U.S. Pat. 5,185,106. In such a passive column, each layer utilizes the velocity and kinetic energy of the fluids to perform the dual function of eliminating heavy liquid entr~nm~nt in the ascending liquid phase and the thorough contacting of the light and heavy liquids to accomplish sufficient separation or extraction of the fluids into desired components. Oppositely inclined, corrugated lamellae, or plates, have thus been utilized in the prior art for affording multiple light phase passages through the horizontal and vertical planes of the packing layers to insure the flow of lighter liquid and distribution thereof within the lamellae and to prevent maldistribution, or channeling, of the lighter liquid through certain portions of the layers and not others. Only in this manner is efficient and effective utilization of the column and the energy applied therein effected.
Addressing still the structured packing of such towers, the structural configuration of the inclined, corrugated contact plates of the prior art variety have incorporated holes for liquid passage. Turbulence is create-d ~ such holes to insure intimate iigh~ and heavy phase contact. It is necessary to insure that the ascending light phase performs a dual function of phase contact and liquid disentrA;nm~nt within close proximity to the vertical location at which the ascending phase approaches or leaves the passage holes. In this mAnn~r, maldistribution of the ascending or descending phases is reduced. It is, moreover, a paramount concern of the prior art to provide such methods and apparatus for liquid-liquid contact in a configuration of economical manufacture. Such considerations are necessary for cost effective operation.
wo97/10886 PCT~S96/12997 Oppositely inclined corrugated plates provide but one method and apparatus ~or counter-current liquid-liquid interaction. With such packing arrays, the liquid introduced at or near the top o~ the column and withdrawn at the bottom, is e~fectively engaged by the separate liquid stream being introduced at or near the bottom o~
the column and withdrawn at the top. The critical feature in such methods and apparatus is to insure that the ~irst and second liquids achieve the desired degree of contact with each other so that the planned mass or energy transfer occurs at the designed rate. The internal structure may be active or passive depending on whether or not it is power-driven externally. There are, however, established reasons for utilizing active systems.
One prior art perception is that passive, packed columns give poor results compared to active columns.
One of the problems is channeling which results in very little contact between liquids. Another problem is the size o~ the first liquid phase droplets dispersed into a second continuous liguid phase. Through agitator systems, the droplets of a first liquid can become extremely ~ine and remain dispersed in a second liquid ~ ~or longer periods of time. One example of an active extraction column is the Scheibel type extraction apparatus as shown in U.S. Patent No. 2,493,265. One aspect o~ the invention set forth in this re~erence comprises a substantially vertical column or chamber provided with a mixing section in which one or more agitators are installed to promote intimate contact between the liquids so as to cause equilibrium contact between them. Above and below the m; ~; ng chambers are c~l m; ng sections where layers of ~ibrous packing, preferably of the self-supporting type, as for example, a roll of tubular knitted wire mesh, are mounted. As set ~orth in the Scheibel patent, the packing in the calming sections stops the circular motion of the liquids and permits them to separate. Thus, in the lower layer o~
packing, the heavier liquid settles out and ~lows downwardly, countercurrently to and through a rising stream o~ lighter liquid. Similarly, in the upper layer of packing the rising stream of lighter liquid flows countercurrently to and through a descending stream of heavier liquid. The agitators are mounted on a central sha~t extending through the column and the sha~t is rotated by any suitable device such as a motor. Other countercurrent contractor designs are set ~orth and shown in U.S. Patent No. 2,072,382, 3,032,403, and 4,855,113.
W O 97/10886 PCTrUS96/12997 - A more recent Scheibel patent design is set forth and shown in U.S. Patent No. 2,850,362. In this system, self-supporting wire mesh screen extending vertically through the entire calming section is again set forth and shown.
The concept o~ agitated extraction columns with structured packing is not new, as seen in the column of L. Steiner and S. Hartland described in CEP December 1980 (page 60) incorporated herein by reference. However, many problems have surfaced in the development and testing of these designs. One such problem is the ~bypassing of liquid" around the packing. For this and other reasons, the commercial applications of such systems have been limited.
Liquid liquid contacting systems are distinctly di~ferent from gas-liquid contacting systems, although both systems may use structured packing. In gas-liquid contacting systems, the liquid phase wets the packing and mass transfer is afforded from the liquid phase on the packing surface from a continuous gas phase flowing thereover. In agitated extraction columns, a first liquid phase is dispersed into a second continuous phase in the form of droplets. As recited above, the droplets can become extremely fine through agitation and it is W O 97/10886 PCT~US96/12997 very desirable to have the dispersed phase droplets remain dispersed throughout the entire column. In view of this operation parameter, it is advantageous to have the packing of such liquid-liquid systems not be wetted by the dispersed phase. It is well known that metal surfaces are more e~ficient for keeping organic phases dispersed than Teflon surfaces which are more ef~ective for keeping aqueous phases dispersed. The function of the packing within agitated-packed systems is mainly to provide a restriction or "roadblock" to increase the number of dispersed phase droplets per unit volume of counter flowing continuous phase. By means of increased dispersed phase holdup, improved mass transfer may be realized. If, however, the holdup is too severe, the flow can be reduced to the point at which the droplets collide one with the other to form a continuous phase.
This condition is referred to as flooding. Flooding then becomes the end condition at which point the e~iciency of the tower performance drops o~f and no further increase in flow rates may be achieved. Because of this limitation, it is important to consider the size of the droplets (which is ef~ectively controlled by the agitator design) and the dispersed phase holdup (which is WO 97/10886 PCTrUS96/12997 effectively set by the structured packing, hydraulic diameter design~ in agitated-packed system designs.
It would be an advantage, therefore, to provide an advance over the prior art by providing an improved, agitated extraction column with an e~ective design ~or and effective placement of structured packing in the c~l m; ng regions thereo~ for improving the liquid-liquid extraction efficiency therein. Such methods and an apparatus are provided by the system of the present invention which provides a structured array of corrugated plates positioned in such a con~iguration so as to e~fectively present an efficient liquid-liquid extraction assembly in axially alternating transverse calming regions of a liquid-liquid extraction tower. The present invention also provides improvements in the hydraulic diameter effectiveness by utilizing a larger crimp height ~or the structured packing and number of layered packing elements rotated with respect to one another.
~llmm~ry of the Invent;o~
The present invention pertains to agitated extraction columns and more particularly one aspect of the present invention pertains to countercurrent, liquid-liquid extraction systems comprising a substantially vertical column having a central axis therethrough and including a series of axially alternating transverse calming and mixing sections therein. Agitation devices are disposed within each of the m; ~; ng sections ~or exerting a non-vertical thrust to the liquid ~lowing therein. Structured packing is mounted within the C~ 1 m; ng sections and between the m; ~; ng sections, and the structured packing mounted within the calming sections comprises at least one layer o~ corrugated contact plates disposed in generally ~ace-to-~ace relationship ~or ~acilitating the ~low o~ liquid therebetween.
In another aspect, the above described invention includes corrugated plates disposed with opposed corrugations inclined oppositely one to the other and at an angle relative to the vertical axis o~ the column.
The corrugated plates disposed within the ~l m; ng sections have corrugations orientated at an angle on the order o~ 45~ relative to the axis o~ the column. The corrugations o~ the plates may be formed with a height on the order o~ one-hal~ inch and may have a generally smooth sur~ace ~inish. In one embodiment, the plates are ~oil-like and are ~ormed ~rom metal. In another embodiment the plates are either ~ormed ~rom or coated wo97/10886 PCT~S96/12997 - with a class of engineering plastics including Teflon and polypropylene.
In yet another aspect, .he above described invention includes at least two axial layers of packing, transversely disposed within each of the calming sections. The packing is preferably arranged with at least a second layer o~ packing rotated on the order of 9O~ relative to a first layer of packing to enhance the edge sealing between said packing and said column. In yet another embodiment, a third layer of packing is provided contiguous to the second layer of packing and rotated on the order of 9O~ relative thereto and so on if there are more than three layers.
In yet another aspect, the present invention relates to a method of counter-current liquid-liquid extraction of the type performed in a substantially vertical column with a series of axially alternating, transverse calming and mixing sections. The method comprises the steps of providing the mixing sections with at least one agitator therein for exerting a non-vertical thrust to the liquid and providing structured packing of the corrugated variety. The structured packing is then mounted within the c~l m; ~g sections and the structured packing with at least one layer of corrugated contact plates disposed in W O 97/10886 PCT~US96/12997 generally face-to-face relationship within said calming sections. The method may further include the steps o~
disposing the corrugated metal sheets with opposed corrugations inclined oppositely one to the other and at an angle relative to the vertical axis o~ the column.
Rr; ef Descr~pt;on o~ the Dr~wings For a more complete underst~n~;ng o~ the present invention and for further objects and advantages thereo~, reference may now be had to the following description taken in conjunction with the accompanying drawings in which:
Fig. 1 is a diagrammatic elevational schematic o~ a plant illustrating an agitated extraction system in accordance with the principles of the present invention;
Fig. 2 is a side elevational cross-sectional view o~
a diagrammatic illustration o~ an agitated-packed column constructed in accordance with the principles of the present invention;
FIG. 3A is a graphical representation illustrating the distribution of acetone between toluene and water with the system of FIG. 1;
Wo97/10886 PCT~S96/12997 Fig. 3B is a graph of theoretical stages per meter versus RPM of the agitator paddles for a first structured packing size with the system of FIG. l;
Fig. 4 is a graph of a theoretical stages per meter versus RPM for a second structured packing size with the system of FIG. l;
Fig. 5 is a StiChl mai r-type plot showing maximum theoretical stages per meter for versus total flow for the two different structured packing sizes of Figs. 3 and 4; and Fig. 6 is a graph of volumetric efficiency verses total ~low with mass transfer from the continuous to dispersed phase for the structured packing of Figs. 3 and 4;
Fig. 7 is an enlarged fragmentary exploded perspective view of the assembly of the structured packing of Fig. 2 in accordance with the principles of the present invention.
~et~;le~ Descr;pt;on Re~erring ~irst to Fig. l, there is shown a diagrammatic schematic of one embodiment of an agitated-packed column system constructed in accordance with the principles of the present invention. The system lO
WO 97/10886 PCT~US96/12997 comprises a column 12 constructed with a plurality o~
calming sections 14 and mixing sections 16 therein. In combination, the assembly of the column 12 provides a counter-current, liquid-liquid extraction system having a shaft 18 positioned along a central axis 26. The sha~t 18 is constructed with paddles 28 disposed within each mixing section 16 ~or exerting a non-vertical thrust to liquid ~lowing therein. Each calming section 14 ~urther includes structured packing 20 mounted therein, between the m; ~; ng sections 16 with the structured packing comprising at least one layer o~ corrugated contact plates disposed in generally ~ace-to-~ace relationship ~or ~acilitating the ~low o~ liquid there between as will be described in more detail ~elow.
It should be noted that Fig. 1 is a schematic illustration which shows a simple system ~or illustrating the principles o~ the present invention. The schematic illustration is itsel~ a diagram of a pilot plant operation, but is equally applicable and convertible to a commercial system by those skilled in the art.
Re~erring still to Fig. 1 a variable speed drive motor 22 is secured at the top 24 o~ column 12 ~or powering mixing sections 16. The drive motor 22 rotates the sha~t 18 extending down the axis 260~ the column 12.
.
WO97/10886 PCT~S96/l2997 Paddles 28 are installed in the mixing sections 16 to generate the agitation o~ the liquids therein from the rotation o~ the shaft 18 as the liquids pass in countercurrent flow therethrough. The agitation imparted thereto is designed to reduce the size o~ liquid phase droplets dispersed into another continuous phase liquid.
Vertical blades 29 are thus assembled to paddles 28 to create agitation with a non-vertical thrust. Agitation ~rom blades 29 and the like has been shown to produce an extremely ~ine dispersed droplet con~iguration in such assemblies.
The first, or heavier, liquid 30 is thus shown to be provided in a reservoir or drum 32 adjacent the column 12 and pumped to the top 24 of said column by a,,pum,p 34. A
~low measurement system 36 is diagrammatically shown for monitoring the liquid ~low rates. The liquid 30 is forced from pump 34 through conduit 38 into the top 24 of column 12 while lighter liquid 40 is pumped into the bottom 42 of the column 12. ~ighter liquid 40, shown herein in the form of organic solvent, is provided in a drum or reservoir 44 and forced through pump 46 through pipes 48 into the bottom 42 of the column 12. A flow calibration measurement system 49 is likewise shown.
When the heavier liquid 30 has descended through the WO 97/10886 PCT~US96/12997 agitated packed extraction column 12, it is carried ~rom the bottom 42 through discharge line 50 into a reservoir, shown herein as a drum 52. A pump 54 may be utilized to ~orce the liquid 30 into the drum 52, which liquid 30 is generally re~erred to as aqueous under~low or ra~inate 56. Likewise, the lighter, organic solvent 40 passes upwardly through column 12 and is carried away ~rom the top 24 through discharge line 60 past vent 62 into a reservoir, shown herein as a drum 64, where it is accumulated as an organic over~low or extract 66. Mesh pad coalescers (not shown) were used in the pilot plant tests as is conventional in the chemical process tower art.
Re~erring now to Fig. 2 there is shown the column 12 o~ Fig. 1 with the variable speed drive motor 22 disposed thereabove. In this particular side elevational, cross-sectional view, the calming sections 14 are shown in more detail. Each section 14 contains structured packing 20 in three distinct layers. The structured packing 20 in each of the calming sections 14 is comprised o~ a ~irst bottom layer 67 o~ corrugated packing ~acing a ~irst direction with a second layer 68 o~ corrugated packing disposed thereabove and orientated into a second direction. The orientation o~ layers 67 and 68 are CA 02232382 l998-03-l7 Wo97/10886 PCT~S96/12997 - described in more detail below. A third packing layer 69 is disposed above second layer 68, which third layer 69 is also rotated relative to second layer 68. In this particular illustration, the bottom 42 of the tower 12 is shown to be constructed with a sufficient axial length to provide for an organic solvent distributor 70. The distributor 70 distributes the flow of the lighter fluid 40 upwardly through column 12 while an aqueous feed distributor 72 is disposed in the upper region of the column 12 for distributing the heavier liquid 30 downwardly therein. This particular system design has been utilized in the analysis of the present invention as part of pilot plant tests utilizing a column having a relatively small diameter (on the order of 3 inches).
Other test parameters and results will be set forth below.
Re~erring still to Fig. 2, one aspect of the present invention is the utilization o~ corrugated metal packing in the calming sections 14. In a preferred embodiment, the layers 67, 68 and 69 of calming section 14 are rotated 90~ relative to each other and are formed of smooth, impervious corrugated metal structured packing.
This packing configuration is used in the present invention to replace the mesh packing of the Scheibel WO 97/10886 PCT~US96/12997 mesh-type extraction apparatus o~ U.S. Patent 2,493,265.
It was ~ound during the test o~ this assembly that this substitution permitted a six fold increase in processing capacity to be realized at volumetric efficiencies which are comparable, i~ not higher, than prior art designs.
TESTS UTILIZING THE PRESENT INVENTION
Pilot plant extraction column tests were performed to demonstrate the performance o~ an agitated-packed extraction column o~ the type shown in Fig. 2 with a st~n~d acetone-water-toluene system. The two extraction columns evaluated were patterned a~ter the original Scheibel mesh column as shown in U.S. Patent No.
R~CKGROUND OF T~ I~ V t~ ON
F;el~ of the Tnvent;Qn The present invention pertains to chemical process towers and, more particularly, to agitated extraction columns assembled with structured packing.
H;story of the Pr;or Art In the liquid-liquid contact art, it is highly desirable to utilize methods and apparatus that efficiently improve the quantity of mass transfer occurring in process towers. This is generally Wo97/10886 PCT~S96/12997 accomplished with countercurrent liquid extraction systems. Liquids of such systems flow continuously and countercurrently through one or more chambers which may have specially designed apparatus mounted therein.
Apparatus of this type may include agitators for affecting the physical properties (e.g., droplet size) of the liquid and tower packing which serves to obstruct the direct flow of the liquids. Packing also provides better contact between lighter rising liquids and heavier settling liquids, and better contact means higher efficiency.
Liquid-liquid process towers are generally constructed to provide descending heavy liquid flow from an upper portion of the tower and ascending liqht li~uid from a lower portion of the tower. It has been found desirable in the liquid-liquid contact portion of the prior art to provide apparatus and methods affording efficient mass transfer, or liquid-liquid contact, whereby contact of the fluids can be accomplished with a minimum pressure drop through a given zone of minimum ~;menqions~ High efficiency and low pressure drop are important design criteria in liquid-liquid extraction operations. Sufficient surface area for liquid-liquid contact is necessary for the primary function in the reduction or elimination of heavy liquid entrainment present in the ascending lighter liquid. Most often, it is necessary for the structured packing array in the column or in the calming zone of agitated extraction systems to have sufficient surface area in both its horizontal and vertical plane so that fractions of the heavy constituents are conducted downwardly, and the lighter liquid is permitted to rise upwardly through the packing with minimum resistance. With such apparatus, heavy and light constituents of the feed are recovered at the bottom and top of the tower, respectively.
A passive liquid-liquid tower (no mechanically induced agitation), generally includes a plurality of stacked layers affording compatible and complemental design. Such a design is set forth, shown and discussed in U.S. Pat. 5,185,106. In such a passive column, each layer utilizes the velocity and kinetic energy of the fluids to perform the dual function of eliminating heavy liquid entr~nm~nt in the ascending liquid phase and the thorough contacting of the light and heavy liquids to accomplish sufficient separation or extraction of the fluids into desired components. Oppositely inclined, corrugated lamellae, or plates, have thus been utilized in the prior art for affording multiple light phase passages through the horizontal and vertical planes of the packing layers to insure the flow of lighter liquid and distribution thereof within the lamellae and to prevent maldistribution, or channeling, of the lighter liquid through certain portions of the layers and not others. Only in this manner is efficient and effective utilization of the column and the energy applied therein effected.
Addressing still the structured packing of such towers, the structural configuration of the inclined, corrugated contact plates of the prior art variety have incorporated holes for liquid passage. Turbulence is create-d ~ such holes to insure intimate iigh~ and heavy phase contact. It is necessary to insure that the ascending light phase performs a dual function of phase contact and liquid disentrA;nm~nt within close proximity to the vertical location at which the ascending phase approaches or leaves the passage holes. In this mAnn~r, maldistribution of the ascending or descending phases is reduced. It is, moreover, a paramount concern of the prior art to provide such methods and apparatus for liquid-liquid contact in a configuration of economical manufacture. Such considerations are necessary for cost effective operation.
wo97/10886 PCT~S96/12997 Oppositely inclined corrugated plates provide but one method and apparatus ~or counter-current liquid-liquid interaction. With such packing arrays, the liquid introduced at or near the top o~ the column and withdrawn at the bottom, is e~fectively engaged by the separate liquid stream being introduced at or near the bottom o~
the column and withdrawn at the top. The critical feature in such methods and apparatus is to insure that the ~irst and second liquids achieve the desired degree of contact with each other so that the planned mass or energy transfer occurs at the designed rate. The internal structure may be active or passive depending on whether or not it is power-driven externally. There are, however, established reasons for utilizing active systems.
One prior art perception is that passive, packed columns give poor results compared to active columns.
One of the problems is channeling which results in very little contact between liquids. Another problem is the size o~ the first liquid phase droplets dispersed into a second continuous liguid phase. Through agitator systems, the droplets of a first liquid can become extremely ~ine and remain dispersed in a second liquid ~ ~or longer periods of time. One example of an active extraction column is the Scheibel type extraction apparatus as shown in U.S. Patent No. 2,493,265. One aspect o~ the invention set forth in this re~erence comprises a substantially vertical column or chamber provided with a mixing section in which one or more agitators are installed to promote intimate contact between the liquids so as to cause equilibrium contact between them. Above and below the m; ~; ng chambers are c~l m; ng sections where layers of ~ibrous packing, preferably of the self-supporting type, as for example, a roll of tubular knitted wire mesh, are mounted. As set ~orth in the Scheibel patent, the packing in the calming sections stops the circular motion of the liquids and permits them to separate. Thus, in the lower layer o~
packing, the heavier liquid settles out and ~lows downwardly, countercurrently to and through a rising stream o~ lighter liquid. Similarly, in the upper layer of packing the rising stream of lighter liquid flows countercurrently to and through a descending stream of heavier liquid. The agitators are mounted on a central sha~t extending through the column and the sha~t is rotated by any suitable device such as a motor. Other countercurrent contractor designs are set ~orth and shown in U.S. Patent No. 2,072,382, 3,032,403, and 4,855,113.
W O 97/10886 PCTrUS96/12997 - A more recent Scheibel patent design is set forth and shown in U.S. Patent No. 2,850,362. In this system, self-supporting wire mesh screen extending vertically through the entire calming section is again set forth and shown.
The concept o~ agitated extraction columns with structured packing is not new, as seen in the column of L. Steiner and S. Hartland described in CEP December 1980 (page 60) incorporated herein by reference. However, many problems have surfaced in the development and testing of these designs. One such problem is the ~bypassing of liquid" around the packing. For this and other reasons, the commercial applications of such systems have been limited.
Liquid liquid contacting systems are distinctly di~ferent from gas-liquid contacting systems, although both systems may use structured packing. In gas-liquid contacting systems, the liquid phase wets the packing and mass transfer is afforded from the liquid phase on the packing surface from a continuous gas phase flowing thereover. In agitated extraction columns, a first liquid phase is dispersed into a second continuous phase in the form of droplets. As recited above, the droplets can become extremely fine through agitation and it is W O 97/10886 PCT~US96/12997 very desirable to have the dispersed phase droplets remain dispersed throughout the entire column. In view of this operation parameter, it is advantageous to have the packing of such liquid-liquid systems not be wetted by the dispersed phase. It is well known that metal surfaces are more e~ficient for keeping organic phases dispersed than Teflon surfaces which are more ef~ective for keeping aqueous phases dispersed. The function of the packing within agitated-packed systems is mainly to provide a restriction or "roadblock" to increase the number of dispersed phase droplets per unit volume of counter flowing continuous phase. By means of increased dispersed phase holdup, improved mass transfer may be realized. If, however, the holdup is too severe, the flow can be reduced to the point at which the droplets collide one with the other to form a continuous phase.
This condition is referred to as flooding. Flooding then becomes the end condition at which point the e~iciency of the tower performance drops o~f and no further increase in flow rates may be achieved. Because of this limitation, it is important to consider the size of the droplets (which is ef~ectively controlled by the agitator design) and the dispersed phase holdup (which is WO 97/10886 PCTrUS96/12997 effectively set by the structured packing, hydraulic diameter design~ in agitated-packed system designs.
It would be an advantage, therefore, to provide an advance over the prior art by providing an improved, agitated extraction column with an e~ective design ~or and effective placement of structured packing in the c~l m; ng regions thereo~ for improving the liquid-liquid extraction efficiency therein. Such methods and an apparatus are provided by the system of the present invention which provides a structured array of corrugated plates positioned in such a con~iguration so as to e~fectively present an efficient liquid-liquid extraction assembly in axially alternating transverse calming regions of a liquid-liquid extraction tower. The present invention also provides improvements in the hydraulic diameter effectiveness by utilizing a larger crimp height ~or the structured packing and number of layered packing elements rotated with respect to one another.
~llmm~ry of the Invent;o~
The present invention pertains to agitated extraction columns and more particularly one aspect of the present invention pertains to countercurrent, liquid-liquid extraction systems comprising a substantially vertical column having a central axis therethrough and including a series of axially alternating transverse calming and mixing sections therein. Agitation devices are disposed within each of the m; ~; ng sections ~or exerting a non-vertical thrust to the liquid ~lowing therein. Structured packing is mounted within the C~ 1 m; ng sections and between the m; ~; ng sections, and the structured packing mounted within the calming sections comprises at least one layer o~ corrugated contact plates disposed in generally ~ace-to-~ace relationship ~or ~acilitating the ~low o~ liquid therebetween.
In another aspect, the above described invention includes corrugated plates disposed with opposed corrugations inclined oppositely one to the other and at an angle relative to the vertical axis o~ the column.
The corrugated plates disposed within the ~l m; ng sections have corrugations orientated at an angle on the order o~ 45~ relative to the axis o~ the column. The corrugations o~ the plates may be formed with a height on the order o~ one-hal~ inch and may have a generally smooth sur~ace ~inish. In one embodiment, the plates are ~oil-like and are ~ormed ~rom metal. In another embodiment the plates are either ~ormed ~rom or coated wo97/10886 PCT~S96/12997 - with a class of engineering plastics including Teflon and polypropylene.
In yet another aspect, .he above described invention includes at least two axial layers of packing, transversely disposed within each of the calming sections. The packing is preferably arranged with at least a second layer o~ packing rotated on the order of 9O~ relative to a first layer of packing to enhance the edge sealing between said packing and said column. In yet another embodiment, a third layer of packing is provided contiguous to the second layer of packing and rotated on the order of 9O~ relative thereto and so on if there are more than three layers.
In yet another aspect, the present invention relates to a method of counter-current liquid-liquid extraction of the type performed in a substantially vertical column with a series of axially alternating, transverse calming and mixing sections. The method comprises the steps of providing the mixing sections with at least one agitator therein for exerting a non-vertical thrust to the liquid and providing structured packing of the corrugated variety. The structured packing is then mounted within the c~l m; ~g sections and the structured packing with at least one layer of corrugated contact plates disposed in W O 97/10886 PCT~US96/12997 generally face-to-face relationship within said calming sections. The method may further include the steps o~
disposing the corrugated metal sheets with opposed corrugations inclined oppositely one to the other and at an angle relative to the vertical axis o~ the column.
Rr; ef Descr~pt;on o~ the Dr~wings For a more complete underst~n~;ng o~ the present invention and for further objects and advantages thereo~, reference may now be had to the following description taken in conjunction with the accompanying drawings in which:
Fig. 1 is a diagrammatic elevational schematic o~ a plant illustrating an agitated extraction system in accordance with the principles of the present invention;
Fig. 2 is a side elevational cross-sectional view o~
a diagrammatic illustration o~ an agitated-packed column constructed in accordance with the principles of the present invention;
FIG. 3A is a graphical representation illustrating the distribution of acetone between toluene and water with the system of FIG. 1;
Wo97/10886 PCT~S96/12997 Fig. 3B is a graph of theoretical stages per meter versus RPM of the agitator paddles for a first structured packing size with the system of FIG. l;
Fig. 4 is a graph of a theoretical stages per meter versus RPM for a second structured packing size with the system of FIG. l;
Fig. 5 is a StiChl mai r-type plot showing maximum theoretical stages per meter for versus total flow for the two different structured packing sizes of Figs. 3 and 4; and Fig. 6 is a graph of volumetric efficiency verses total ~low with mass transfer from the continuous to dispersed phase for the structured packing of Figs. 3 and 4;
Fig. 7 is an enlarged fragmentary exploded perspective view of the assembly of the structured packing of Fig. 2 in accordance with the principles of the present invention.
~et~;le~ Descr;pt;on Re~erring ~irst to Fig. l, there is shown a diagrammatic schematic of one embodiment of an agitated-packed column system constructed in accordance with the principles of the present invention. The system lO
WO 97/10886 PCT~US96/12997 comprises a column 12 constructed with a plurality o~
calming sections 14 and mixing sections 16 therein. In combination, the assembly of the column 12 provides a counter-current, liquid-liquid extraction system having a shaft 18 positioned along a central axis 26. The sha~t 18 is constructed with paddles 28 disposed within each mixing section 16 ~or exerting a non-vertical thrust to liquid ~lowing therein. Each calming section 14 ~urther includes structured packing 20 mounted therein, between the m; ~; ng sections 16 with the structured packing comprising at least one layer o~ corrugated contact plates disposed in generally ~ace-to-~ace relationship ~or ~acilitating the ~low o~ liquid there between as will be described in more detail ~elow.
It should be noted that Fig. 1 is a schematic illustration which shows a simple system ~or illustrating the principles o~ the present invention. The schematic illustration is itsel~ a diagram of a pilot plant operation, but is equally applicable and convertible to a commercial system by those skilled in the art.
Re~erring still to Fig. 1 a variable speed drive motor 22 is secured at the top 24 o~ column 12 ~or powering mixing sections 16. The drive motor 22 rotates the sha~t 18 extending down the axis 260~ the column 12.
.
WO97/10886 PCT~S96/l2997 Paddles 28 are installed in the mixing sections 16 to generate the agitation o~ the liquids therein from the rotation o~ the shaft 18 as the liquids pass in countercurrent flow therethrough. The agitation imparted thereto is designed to reduce the size o~ liquid phase droplets dispersed into another continuous phase liquid.
Vertical blades 29 are thus assembled to paddles 28 to create agitation with a non-vertical thrust. Agitation ~rom blades 29 and the like has been shown to produce an extremely ~ine dispersed droplet con~iguration in such assemblies.
The first, or heavier, liquid 30 is thus shown to be provided in a reservoir or drum 32 adjacent the column 12 and pumped to the top 24 of said column by a,,pum,p 34. A
~low measurement system 36 is diagrammatically shown for monitoring the liquid ~low rates. The liquid 30 is forced from pump 34 through conduit 38 into the top 24 of column 12 while lighter liquid 40 is pumped into the bottom 42 of the column 12. ~ighter liquid 40, shown herein in the form of organic solvent, is provided in a drum or reservoir 44 and forced through pump 46 through pipes 48 into the bottom 42 of the column 12. A flow calibration measurement system 49 is likewise shown.
When the heavier liquid 30 has descended through the WO 97/10886 PCT~US96/12997 agitated packed extraction column 12, it is carried ~rom the bottom 42 through discharge line 50 into a reservoir, shown herein as a drum 52. A pump 54 may be utilized to ~orce the liquid 30 into the drum 52, which liquid 30 is generally re~erred to as aqueous under~low or ra~inate 56. Likewise, the lighter, organic solvent 40 passes upwardly through column 12 and is carried away ~rom the top 24 through discharge line 60 past vent 62 into a reservoir, shown herein as a drum 64, where it is accumulated as an organic over~low or extract 66. Mesh pad coalescers (not shown) were used in the pilot plant tests as is conventional in the chemical process tower art.
Re~erring now to Fig. 2 there is shown the column 12 o~ Fig. 1 with the variable speed drive motor 22 disposed thereabove. In this particular side elevational, cross-sectional view, the calming sections 14 are shown in more detail. Each section 14 contains structured packing 20 in three distinct layers. The structured packing 20 in each of the calming sections 14 is comprised o~ a ~irst bottom layer 67 o~ corrugated packing ~acing a ~irst direction with a second layer 68 o~ corrugated packing disposed thereabove and orientated into a second direction. The orientation o~ layers 67 and 68 are CA 02232382 l998-03-l7 Wo97/10886 PCT~S96/12997 - described in more detail below. A third packing layer 69 is disposed above second layer 68, which third layer 69 is also rotated relative to second layer 68. In this particular illustration, the bottom 42 of the tower 12 is shown to be constructed with a sufficient axial length to provide for an organic solvent distributor 70. The distributor 70 distributes the flow of the lighter fluid 40 upwardly through column 12 while an aqueous feed distributor 72 is disposed in the upper region of the column 12 for distributing the heavier liquid 30 downwardly therein. This particular system design has been utilized in the analysis of the present invention as part of pilot plant tests utilizing a column having a relatively small diameter (on the order of 3 inches).
Other test parameters and results will be set forth below.
Re~erring still to Fig. 2, one aspect of the present invention is the utilization o~ corrugated metal packing in the calming sections 14. In a preferred embodiment, the layers 67, 68 and 69 of calming section 14 are rotated 90~ relative to each other and are formed of smooth, impervious corrugated metal structured packing.
This packing configuration is used in the present invention to replace the mesh packing of the Scheibel WO 97/10886 PCT~US96/12997 mesh-type extraction apparatus o~ U.S. Patent 2,493,265.
It was ~ound during the test o~ this assembly that this substitution permitted a six fold increase in processing capacity to be realized at volumetric efficiencies which are comparable, i~ not higher, than prior art designs.
TESTS UTILIZING THE PRESENT INVENTION
Pilot plant extraction column tests were performed to demonstrate the performance o~ an agitated-packed extraction column o~ the type shown in Fig. 2 with a st~n~d acetone-water-toluene system. The two extraction columns evaluated were patterned a~ter the original Scheibel mesh column as shown in U.S. Patent No.
2,493,265 (hereafter the "Scheibel m~sh column") with the mesh sections replaced with the above described higher corrugated, capacity structured packing. With both packings described herein, active heights of 30" which contained ~our (4) actual stages were used in 3" diameter extraction columns. Agitation was provided with standard 4-bladed radial turbines o~ the type typically used in a 3" diameter Scheibel mesh column. Tests with both acetone mass transfer from the continuous aqueous phase to dispersed organic phase (c-d) and dispersed organic to continuous aqueous phase (d-c) were per~ormed, but a W O 97/10886 PCTrUS96/12997 detailed analysis of only the (c-d) mass trans~er data is presented.
The tests were conducted with a smooth surface, unper~orated crimp structured packing of 3/8" and ~"
crimp sizes. The smaller crimp size is attributable to the small diameter of the column as compared to commercial columns. With larger, commercial columns, the crimp size would preferably increase to as much as three inches. In the tests with the 3/8" crimp, combined feed and solvent ~low rates from 10 to 50 m3/(m2/hr) were considered and agitator speeds from 300 to 1750 rpm were used. The maximum theoretical stages per meter ranged from 3.83 at 10 m3(m2/hr) to a m~x;mllm of 5.91 at 20 m3/(m2hr), with a decrease at higher processing rates to 2.11 stages/meter at a combined throughput of 49.89 m3/(m2hr). The m~x;mllm volumetric e~iciency (at optimum rpm) increased ~rom 38.3 HR-1 at a combined throughput of 10 m3/(m2hr) to a maximum o~ 186.8 HR-1 at 40 m3/(m2hr) and then it fell o~ to 106 HR 1 at 49.89 m3/(m2hr).
In the tests with the ~" crimp packing, combined throughputs from 10.58 to 41.01 m3/(m2hr) were considered - and agitator speeds from 450 to 1700 rpm were used. The maximum theoretical stages per meter ranged ~rom 5.2 at 10.58 m3/(m2hr) to a maximum of 7 14 stages per meter at CA 02232382 Isg8-03-l7 Wo97/10886 PCT~S96/1~997 20.48 m3/(m2hr) with a decrease a higher processing rates to 2.74 stages/hr at a combined throughput of 49.89 m3/(m2hr). The m~; mum volumetric efficiency increased from 55.5 HR-1 at 10.58 m3/(m2hr) to 154.6 HR-at 30.73 m3/(m2hr) and then it fell off to 112.4 HR_l at 41.01 m /(m hr).
By replacing the mesh in the original Scheibel mesh column with 3/8" and crimp structured packing, combined processing rates increased from lO m3/(m2hr) to as high as 40 m3/(m2hr) with volumetric efficiencies over 150 HR-l. This data indicates a six-fold increase in capacity with excellent volumetric efficiency The above tests were performed to (l)evaluate the performance of a 3" diameter agitated-~acked column with 3/8" structured packing with the standard acetone water-toluene system at room temperature processing conditions, and (2) to evaluate the performance of a 3" diameter agitated-packed column with ~" crimp structured packing with the standard acetone water-toluene system at room temperature processing conditions.
Referring now to Fig. 3A, the equilibrium distribution of acetone between reagent grade toluene and water (steam condensate) phases at room temperature may be seen. These data were obtained by performing shake Wo97/10886 PCT~S96/12997 tests with a l liter round bottom flask. Compositions o~
the resulting ra~inate and extract phases were determined by gas chromatography.
As stated above, Fig. l illustrates a simplified schematic o~ the extraction pilot plant ~rom which the data was taken that is presented herein. The pilot plant included a 3" diameter agitated column 12 with variable speed paddles 28 installed in mixing sections 16, metered supplies o~ ~eed 30 and solvent 40, and collection systems ~or an organic extract over~low 66 and a raf~inate under~low 56. In all cases the organic toluene phase was dispersed in the continuous aqueous phase so the liquid-liquid interface was located at the top o~ the extraction column.
lS Speci~ic geometrics o~ the agitated column 12 tested may be seen in Figures 3B, 4, 5 and 6. Packing ~or the 3/8l' crimp column was ~abricated ~rom structured packing sold under the trademark Gempak~ which is a registered tr~m~k o~ Glitsch, Inc. The Gempak elements were constructed in a 4-3/4" thickness with a 3" outside diameter and were drilled with a ~" hole axially through the center thereo~ ~or receipt o~ the sha~t 18 therethrough (See FIG. 7). Packing ~or the ~" crimp Gempak~ columns was ~abricated ~rom plain sheet metal WO97/10886 PCT~S96/12997 elements (no lances, per~orations or holes) by welding three t3) l~" thick x 3" diameter discs o~ the GempakTM
together to form a 4~" long (high) element. Each disc was rotated 9O~ to the adjacent disc be~ore welding.
Again, a ~" diameter hole was drilled axially through the center o~ each ~inished element ~or passage o~ the agitator shaft 18 therethrough.
Pilot plant test results are shown in Figs. 3B, ~, 5 and 6.Theoretical extraction stages were determined graphically, from operating lines plotted on Figure 3A.
Since the mutual solubility o~ water and toluene is very small in the range studied, an operating line on Figure 3A employing weight ratio units can be assumed to be a straight line. In all tests, the volumetric ~low ratio o~ organic solvent to aqueous ~eed was l.5. There~ore, the operating lines ~or the runs were nearly parallel to the equilibrium line and the resulting extraction ~actor was close to unity. Under these circumstances, HETS
(Height Equivalent o~ Theoretical Stage) and HTU (Height o~ Trans~er Unit) are essentially equal.
The volumetric e~iciency is the product of the total ~low in units o~ m3/(m2hr) and the number o~
theoretical stages per meter Thus volumetric ef~iciency has the units o~ HR-l and is inversely proportional to W O 97/10886 PCT~US96/12997 the volume of column required to do a given extraction job.
Theoretical stages per meter versus rpm ~or the 3/8"
and ~" crimp agitated-packed columns are shown in Figures 3B and 4, respectively. At a combined processing rate of 10 m3/(m2hr) the optimum rpm is 50 to 70~ of the rpm at flooding. At higher processing rates, however, the optimum rpm (highest theoretical stages per meter) is within 5~ of the flood point rpm.
The maximum theoretical stages per meter versus combined processing rate (total flow) on a Stichlmair type plot is shown in FIG. 5. For both 3 /8" and ~" crimp Agitated Packed (AP) columns, the m~x;mllm theoretical stages per meter occurs at approximately 20 m3/m2hr).
Volumetric efficiency versus total flow is shown in FIG. 6. For both 3/8" and ~" crimp agitated-packed colum~s, the m~x;mum volumetric efficiency occurs at approximately 40 m3/(m2hr).
Referring now to FIG.7, there is shown an enlarged, exploded, perspective view of a preferred embodiment of the structured packing 20 of the present invention - disposed within the calming sections 14 of a tower 12 in layers 67, 68 and 69, which correspond to the description in FIG. 2. The individual layers 67, 68 and 69 are W O 97/10886 PCTAUS96/t2997 referred to generally as layers 100. For example, the structured packing 20 is provided in an assembly of multiple packing layers 100. Each layer 100 of packing 20 comprises a plurality of corrugated sheets 102, the corrugations of which are disposed at an angle relative to the tower axis 18 and angularly oriented one to the other in face-to-face relationship. A somewhat similar structured packing array is also shown in U.S. Patent No.
The tests were conducted with a smooth surface, unper~orated crimp structured packing of 3/8" and ~"
crimp sizes. The smaller crimp size is attributable to the small diameter of the column as compared to commercial columns. With larger, commercial columns, the crimp size would preferably increase to as much as three inches. In the tests with the 3/8" crimp, combined feed and solvent ~low rates from 10 to 50 m3/(m2/hr) were considered and agitator speeds from 300 to 1750 rpm were used. The maximum theoretical stages per meter ranged from 3.83 at 10 m3(m2/hr) to a m~x;mllm of 5.91 at 20 m3/(m2hr), with a decrease at higher processing rates to 2.11 stages/meter at a combined throughput of 49.89 m3/(m2hr). The m~x;mllm volumetric e~iciency (at optimum rpm) increased ~rom 38.3 HR-1 at a combined throughput of 10 m3/(m2hr) to a maximum o~ 186.8 HR-1 at 40 m3/(m2hr) and then it fell o~ to 106 HR 1 at 49.89 m3/(m2hr).
In the tests with the ~" crimp packing, combined throughputs from 10.58 to 41.01 m3/(m2hr) were considered - and agitator speeds from 450 to 1700 rpm were used. The maximum theoretical stages per meter ranged ~rom 5.2 at 10.58 m3/(m2hr) to a maximum of 7 14 stages per meter at CA 02232382 Isg8-03-l7 Wo97/10886 PCT~S96/1~997 20.48 m3/(m2hr) with a decrease a higher processing rates to 2.74 stages/hr at a combined throughput of 49.89 m3/(m2hr). The m~; mum volumetric efficiency increased from 55.5 HR-1 at 10.58 m3/(m2hr) to 154.6 HR-at 30.73 m3/(m2hr) and then it fell off to 112.4 HR_l at 41.01 m /(m hr).
By replacing the mesh in the original Scheibel mesh column with 3/8" and crimp structured packing, combined processing rates increased from lO m3/(m2hr) to as high as 40 m3/(m2hr) with volumetric efficiencies over 150 HR-l. This data indicates a six-fold increase in capacity with excellent volumetric efficiency The above tests were performed to (l)evaluate the performance of a 3" diameter agitated-~acked column with 3/8" structured packing with the standard acetone water-toluene system at room temperature processing conditions, and (2) to evaluate the performance of a 3" diameter agitated-packed column with ~" crimp structured packing with the standard acetone water-toluene system at room temperature processing conditions.
Referring now to Fig. 3A, the equilibrium distribution of acetone between reagent grade toluene and water (steam condensate) phases at room temperature may be seen. These data were obtained by performing shake Wo97/10886 PCT~S96/12997 tests with a l liter round bottom flask. Compositions o~
the resulting ra~inate and extract phases were determined by gas chromatography.
As stated above, Fig. l illustrates a simplified schematic o~ the extraction pilot plant ~rom which the data was taken that is presented herein. The pilot plant included a 3" diameter agitated column 12 with variable speed paddles 28 installed in mixing sections 16, metered supplies o~ ~eed 30 and solvent 40, and collection systems ~or an organic extract over~low 66 and a raf~inate under~low 56. In all cases the organic toluene phase was dispersed in the continuous aqueous phase so the liquid-liquid interface was located at the top o~ the extraction column.
lS Speci~ic geometrics o~ the agitated column 12 tested may be seen in Figures 3B, 4, 5 and 6. Packing ~or the 3/8l' crimp column was ~abricated ~rom structured packing sold under the trademark Gempak~ which is a registered tr~m~k o~ Glitsch, Inc. The Gempak elements were constructed in a 4-3/4" thickness with a 3" outside diameter and were drilled with a ~" hole axially through the center thereo~ ~or receipt o~ the sha~t 18 therethrough (See FIG. 7). Packing ~or the ~" crimp Gempak~ columns was ~abricated ~rom plain sheet metal WO97/10886 PCT~S96/12997 elements (no lances, per~orations or holes) by welding three t3) l~" thick x 3" diameter discs o~ the GempakTM
together to form a 4~" long (high) element. Each disc was rotated 9O~ to the adjacent disc be~ore welding.
Again, a ~" diameter hole was drilled axially through the center o~ each ~inished element ~or passage o~ the agitator shaft 18 therethrough.
Pilot plant test results are shown in Figs. 3B, ~, 5 and 6.Theoretical extraction stages were determined graphically, from operating lines plotted on Figure 3A.
Since the mutual solubility o~ water and toluene is very small in the range studied, an operating line on Figure 3A employing weight ratio units can be assumed to be a straight line. In all tests, the volumetric ~low ratio o~ organic solvent to aqueous ~eed was l.5. There~ore, the operating lines ~or the runs were nearly parallel to the equilibrium line and the resulting extraction ~actor was close to unity. Under these circumstances, HETS
(Height Equivalent o~ Theoretical Stage) and HTU (Height o~ Trans~er Unit) are essentially equal.
The volumetric e~iciency is the product of the total ~low in units o~ m3/(m2hr) and the number o~
theoretical stages per meter Thus volumetric ef~iciency has the units o~ HR-l and is inversely proportional to W O 97/10886 PCT~US96/12997 the volume of column required to do a given extraction job.
Theoretical stages per meter versus rpm ~or the 3/8"
and ~" crimp agitated-packed columns are shown in Figures 3B and 4, respectively. At a combined processing rate of 10 m3/(m2hr) the optimum rpm is 50 to 70~ of the rpm at flooding. At higher processing rates, however, the optimum rpm (highest theoretical stages per meter) is within 5~ of the flood point rpm.
The maximum theoretical stages per meter versus combined processing rate (total flow) on a Stichlmair type plot is shown in FIG. 5. For both 3 /8" and ~" crimp Agitated Packed (AP) columns, the m~x;mllm theoretical stages per meter occurs at approximately 20 m3/m2hr).
Volumetric efficiency versus total flow is shown in FIG. 6. For both 3/8" and ~" crimp agitated-packed colum~s, the m~x;mum volumetric efficiency occurs at approximately 40 m3/(m2hr).
Referring now to FIG.7, there is shown an enlarged, exploded, perspective view of a preferred embodiment of the structured packing 20 of the present invention - disposed within the calming sections 14 of a tower 12 in layers 67, 68 and 69, which correspond to the description in FIG. 2. The individual layers 67, 68 and 69 are W O 97/10886 PCTAUS96/t2997 referred to generally as layers 100. For example, the structured packing 20 is provided in an assembly of multiple packing layers 100. Each layer 100 of packing 20 comprises a plurality of corrugated sheets 102, the corrugations of which are disposed at an angle relative to the tower axis 18 and angularly oriented one to the other in face-to-face relationship. A somewhat similar structured packing array is also shown in U.S. Patent No.
4,842,778 assigned to Glitsch, Inc. The plurality of layers are rotationally oriented on the order of 90~ one to the other as represented by phantom line 111 for bi-directional lateral dispersion and full distribution of the liquids passing therethrough. This rotational relationship between layers as rePresented by line 111 affords not only even liquid distribution but also enhances the sealing of the assembly thereo~ relative to the round walls of column 12. This rotational relationship between layers a~fords not only even liquid distribution and improved sealing of the assembly relative to the round walls of column 12, but also increases the dispersed phase holdup in the c~l m; ng sections of said column. For example, a single layer 100 of corrugated sheets 102 seals best against the round inside column walls 104 alona its ends 110 which may be CA 02232382 l998-03-l7 cut more precisely to size. Bypassing o~ liquid around the packing layers 100 is greatly reduced with improvements in the fit between the packing 20 and the inside column walls 104. By disposing rotated layer 68 o~ corrugated sheets 102 above layer 67, the area oi~
least sealing o~ one layer is compensated for by the next layer. As sated above, the enhanced sealing is because the ends 110 o~ the sheets 102 may be sized more to closely ~it against the walls 104 than the sides 113 o~
the corrugated sheets 102. Because o~ this better sealing, bypassing o~ the dispersed phase around the packing 20 is ~n; n;m; zed.
Re~erring still to FIG 7, the multiple packing layers 100 are each constructed with a central aperture 199 ~ormed therein. The apertures 199 oi~ layers 100 are adapted ~or receipt of the sha~t 18 therethrough ~or permitting assembly o~ the paddles 28 in the adjacent mixing section 16 and the rotation thereo~. In this manner, agitation may be imparted to the liquids flowing therein, as described above. In one embodiment o~ the invention the paddles 28, blades 29, sha~t 18, packing layers 100 and the side walls 104 o~ tower 12 are coated with plastic such as polypropylene, Te~lon (a trademark o~ Dupont) or Kymar (a trademark o~ Pennwalt Corp.). The W O 97/10886 PCT~US96/12997 packing layers and other parts, such as paddle blades 29 may actually be ~ormed o~ such plastics. Such plastic coatings can be applied by dip coating and the like and are most use~ul when using the present invention to disperse an aqueous liquid into a continuous organic liquid because aqueous liquids coalesce on metals.
The present invention has thus been shown to provide an improved agitated extraction column with enhanced per~ormance characteristics, but speci~ically, ~IGS. 1, 2 and 7 (now re~erred to in combination) illustrate a countercurrent, liquid-liquid extraction system 10 comprising a substantially vertical column 12 having a central axis 18 therethrough and including a series o~
axially alternating transverse calming sections 14 and mixiny section 16 therein. Agitation means in the ~orm of paddles 28 are disposed within each o~ the mixing sections 16 ~Qr exerting a non-vertical thrust to the liquid ~lowing therein. At least one layer o~ structured packing 20 is mounted within each o~ the calming sections 14 and between the mixing sections 16 and said structured packing mounted within said calming sections comprises at least one layer o~ corrugated contact plates or sheets 102 disposed in generally ~ace-to-~ace relationship ~or facilitating the ~low o~ liquid therebetween.
CA 02232382 l998-03-l7 Wo97/10886 PCT~S96/12997 The corrugated sheets 102 disposed within the calming sections may, as shown, have the corrugations oriented at an angle on the order o~ 45~ relative to the axis 18 o~ the column 12. The corrugations o~ the sheets 102 may be ~ormed with a height on the order o~ one-quarter inch to three inches, depending on the size of the column 12, and may have a generally smooth sur~ace ~inish as described herein, or the sheets may include apertures. In one em~odiment of the invention, the sheets 102 are ~oil-like and are ~ormed ~rom metal. As described above, the sheets 102 may be ~ormed from plastic or coated therewith. In yet another aspect, the pre~erred embodiment o~ the above described invention includes at least two axial layers 100 o~ ~ackin~ 20 transversely disposed within each o~ the calming sections 14. As many as ~ive or more layers are contemplated in certain conventional applications. In this particular .
embodiment, the packing is rotated 90~ relative to a ~irst layer o~ packing to enhance the edge sealing between said packing and the inside walls 104 o~ the column 12.
It is thus believed that the operation and construction o~ the present invention will be apparent ~rom the ~oregoing description. While the method and WO 97/10886 PCT~US96/12997 apparatus shown or described has been characterized as being preferred it will be obvious that various changes and modifications may be made therein without departing from the spirit and scope of the invention as defined in the following claims.
least sealing o~ one layer is compensated for by the next layer. As sated above, the enhanced sealing is because the ends 110 o~ the sheets 102 may be sized more to closely ~it against the walls 104 than the sides 113 o~
the corrugated sheets 102. Because o~ this better sealing, bypassing o~ the dispersed phase around the packing 20 is ~n; n;m; zed.
Re~erring still to FIG 7, the multiple packing layers 100 are each constructed with a central aperture 199 ~ormed therein. The apertures 199 oi~ layers 100 are adapted ~or receipt of the sha~t 18 therethrough ~or permitting assembly o~ the paddles 28 in the adjacent mixing section 16 and the rotation thereo~. In this manner, agitation may be imparted to the liquids flowing therein, as described above. In one embodiment o~ the invention the paddles 28, blades 29, sha~t 18, packing layers 100 and the side walls 104 o~ tower 12 are coated with plastic such as polypropylene, Te~lon (a trademark o~ Dupont) or Kymar (a trademark o~ Pennwalt Corp.). The W O 97/10886 PCT~US96/12997 packing layers and other parts, such as paddle blades 29 may actually be ~ormed o~ such plastics. Such plastic coatings can be applied by dip coating and the like and are most use~ul when using the present invention to disperse an aqueous liquid into a continuous organic liquid because aqueous liquids coalesce on metals.
The present invention has thus been shown to provide an improved agitated extraction column with enhanced per~ormance characteristics, but speci~ically, ~IGS. 1, 2 and 7 (now re~erred to in combination) illustrate a countercurrent, liquid-liquid extraction system 10 comprising a substantially vertical column 12 having a central axis 18 therethrough and including a series o~
axially alternating transverse calming sections 14 and mixiny section 16 therein. Agitation means in the ~orm of paddles 28 are disposed within each o~ the mixing sections 16 ~Qr exerting a non-vertical thrust to the liquid ~lowing therein. At least one layer o~ structured packing 20 is mounted within each o~ the calming sections 14 and between the mixing sections 16 and said structured packing mounted within said calming sections comprises at least one layer o~ corrugated contact plates or sheets 102 disposed in generally ~ace-to-~ace relationship ~or facilitating the ~low o~ liquid therebetween.
CA 02232382 l998-03-l7 Wo97/10886 PCT~S96/12997 The corrugated sheets 102 disposed within the calming sections may, as shown, have the corrugations oriented at an angle on the order o~ 45~ relative to the axis 18 o~ the column 12. The corrugations o~ the sheets 102 may be ~ormed with a height on the order o~ one-quarter inch to three inches, depending on the size of the column 12, and may have a generally smooth sur~ace ~inish as described herein, or the sheets may include apertures. In one em~odiment of the invention, the sheets 102 are ~oil-like and are ~ormed ~rom metal. As described above, the sheets 102 may be ~ormed from plastic or coated therewith. In yet another aspect, the pre~erred embodiment o~ the above described invention includes at least two axial layers 100 o~ ~ackin~ 20 transversely disposed within each o~ the calming sections 14. As many as ~ive or more layers are contemplated in certain conventional applications. In this particular .
embodiment, the packing is rotated 90~ relative to a ~irst layer o~ packing to enhance the edge sealing between said packing and the inside walls 104 o~ the column 12.
It is thus believed that the operation and construction o~ the present invention will be apparent ~rom the ~oregoing description. While the method and WO 97/10886 PCT~US96/12997 apparatus shown or described has been characterized as being preferred it will be obvious that various changes and modifications may be made therein without departing from the spirit and scope of the invention as defined in the following claims.
Claims (52)
1. A countercurrent liquid-liquid extraction system adapted for the flow of liquids therein, said system comprising:
a substantially vertical column having a central axis therethrough and including a series of axially alternating transverse calming and mixing sections;
agitation means disposed within each of said mixing sections for exerting a non-vertical thrust to said liquid flowing therein;
structured packing mounted within said calming sections and between said mixing sections; and said structured packing mounted within said calming sections comprising at least one layer of corrugated contact plates disposed in generally face-to-face relationship for facilitating the flow of liquid therebetween.
a substantially vertical column having a central axis therethrough and including a series of axially alternating transverse calming and mixing sections;
agitation means disposed within each of said mixing sections for exerting a non-vertical thrust to said liquid flowing therein;
structured packing mounted within said calming sections and between said mixing sections; and said structured packing mounted within said calming sections comprising at least one layer of corrugated contact plates disposed in generally face-to-face relationship for facilitating the flow of liquid therebetween.
2. The system as set forth in claim 1 wherein said corrugated plates are disposed with opposed corrugations inclined oppositely one to the other and at an angle relative to the vertical axis of said column.
3. The system as set forth in claim 2 wherein said corrugated plates are disposed within said calming sections with said corrugations orientated at an angle on the order of 45° relative to the axis of said column.
4. The system as set forth in claim 1 wherein said corrugations of said plates are formed with a height on the order of one-quarter inch to three inches.
5. The system as set forth in claim 1 wherein said corrugated plates are formed with smooth, unperforated surfaces.
6. The system as set forth in claim I wherein said plates are formed from metal.
7. The system as set forth in claim 6 wherein said metal plates are formed with smooth, unperforated surfaces.
8. The system as set forth in claim 1 wherein said plates are formed from a class of engineering plastics consisting of Teflon and polypropylene.
9. The system as set forth in claim 1 wherein at least two axially stacked layers of packing are transversely disposed within at least one of said calming sections.
10. The system as set forth in claim 9 wherein two axially stacked layers of packing are disposed within each of said calming sections of said columns.
11. The system as set forth in one of claims 9 or 10 wherein a second layer of packing is rotated 90° relative to a first layer of packing of said two axially stacked layers to enhance the edge sealing between said packing layers and said column to limit the bypass of liquids therearound.
12. The system as set forth in claim 11 wherein a third layer of packing is provided and secured contiguous to said second layer of packing and rotated 90°
relative thereto to further limit the bypass of liquids therearound.
relative thereto to further limit the bypass of liquids therearound.
13. The system as set forth in claim 1 wherein said structured packing comprises corrugated plates formed of metal and disposed with opposed corrugations inclined oppositely one to the other and at an angle on the order of 45° relative to the axis of said column.
14. The system as set forth in claim 1 wherein said agitation means comprises paddles mounted on a common vertical rotatable shaft disposed within said column and passing through said structured packing.
15. The system as set forth in claim 14 wherein said paddles comprise four radial blades disposed symmetrically around said shaft.
16. The system as set forth in claim 1 wherein said column is adapted for the countercurrent flow of a first heavy liquid and a second light liquid, one dispersed into the other.
17. The system as set forth in claim 1 wherein said structured packing and those portions of said agitation means and said column exposed to said liquids comprise plastic surfaces.
18. A method of counter-current liquid-liquid extraction comprising the steps of:
providing a substantially vertical column with a series of axially alternating transverse calming and mixing sections adapted for the flow of liquids therein;
providing said mixing sections with at least one agitator for exerting a non-vertical thrust to said liquid flowing therethrough;
providing structured packing comprising at least one layer of corrugated contact plates disposed in generally face-to-face relationship;
mounting said structured packing within said calming sections; and flowing first and second liquids through said column.
providing a substantially vertical column with a series of axially alternating transverse calming and mixing sections adapted for the flow of liquids therein;
providing said mixing sections with at least one agitator for exerting a non-vertical thrust to said liquid flowing therethrough;
providing structured packing comprising at least one layer of corrugated contact plates disposed in generally face-to-face relationship;
mounting said structured packing within said calming sections; and flowing first and second liquids through said column.
19. The method as set forth in claim 18 and including the step of disposing said corrugated plates with opposed corrugations inclined oppositely one to the other and at an angle relative to the vertical axis of said column.
20. The method as set forth in claim 19 and further including the step of disposing said corrugations within said calming sections with said corrugations orientated at an angle on the order of 45° relative to the axis of said column.
21. The method as set forth in claim 18 and including the step of forming said corrugations of said plates with a height in the range of one-quarter inch to three inches.
22. The method as set forth in claim 18 and including the step of forming said corrugated plates with smooth, unperforated surfaces.
23. The method as set forth in claim 18 and including the step of forming said plates from metal.
24. The method as set forth in claim 18 and including the step of forming said plates from a class of engineering plastics consisting of Teflon and polypropylene.
25. The method as set forth in claim 18 and including the step of mounting at least two axially stacked layers of packing within at least one of said calming sections.
26. The method as set forth in claim 25 and including the step of mounting said two axially stacked layers of packing within each of said calming sections.
27. The method as set forth in one of claims 25 or 26 and including the steps of rotating said second layer of packing 90° relative to said first layer of packing of said two axially stacked layers to enhance the edge sealing between said packing layers and said column to limit the bypass of liquids therearound.
28. The method as set forth in claim 27 and including the steps of providing a third layer of packing for placement contiguous to said second layer of packing and securing said third layer to said second layer at a 90° rotational position to further limit the bypass of liquids therearound.
29. The method as set forth in claim 18 and including the step of providing said agitator with paddles.
30. The method as set forth in claim 29 and including the steps of forming a hole in said layers of packing, providing a common vertical rotatable shaft disposed within said column, passing through said hole in said layers, and mounting said paddles to said shaft.
31. The method as set forth in claim 18 and including the step of providing said liquids in light and heavy phases for countercurrent flow of one through the other.
32. The method as set forth in claim 31 and including the step of dispersing said light phase liquid in a counterflowing, continuous heavy phase liquid.
33. The method as set forth in claim 31 and including the step of dispersing said heavy phase liquid in a counterflowing, continuous light phase liquid.
34. The method as set forth in claim 18 and including the step of providing said structured packing with plastic surfaces.
35. The method as set forth in claim 18 and including the step of providing said agitator and said column surfaces which are in contact with said liquids with plastic surfaces.
36. A method of liquid-liquid extraction for a first, heavy phase liquid and a second, light phase liquid flowing countercurrently in a substantially vertical column constructed with a series of axially alternating transverse calming and mixing sections, said method comprising the steps of:
providing said mixing sections with at least one agitator therein for exerting a non-vertical thrust to said liquid;
providing structured packing comprising at least one layer of corrugated contact plates disposed in generally face-to-face relationship within said calming sections;
mounting said structured packing within said calming sections; and flowing a first, heavy phase liquid and a second, light phase liquid through said column.
providing said mixing sections with at least one agitator therein for exerting a non-vertical thrust to said liquid;
providing structured packing comprising at least one layer of corrugated contact plates disposed in generally face-to-face relationship within said calming sections;
mounting said structured packing within said calming sections; and flowing a first, heavy phase liquid and a second, light phase liquid through said column.
37. The method as set forth in claim 36 and including the step of dispersing said light phase liquid in a counterflowing, continuous heavy phase liquid.
38. The method as set forth in claim 36 and including the step of dispersing said heavy phase liquid in a counterflowing, continuous light phase liquid.
39. The method as set forth in claim 36 and including the step of providing said structured packing, agitator, and column areas which are in contact with said liquids with plastic surfaces.
40. The method as set forth in claim 36 and including the step of forming said corrugated plates with smooth, unperforated surfaces.
41. The method as set forth in claim 36 and including the step of forming said plates from metal.
42. The method as set forth in claim 36 and including the step of mounting at least two axially stacked layers of packing within at least one of said calming sections.
43. The method as set forth in claim 42 and including the step of rotating said second layer of packing 90° relative to said first layer of packing of said two axially stacked layers to enhance the edge sealing between said packing layers and said column to limit the bypass of liquids therearound.
44. The method as set forth in claim 43 and including the steps of mounting a third layer of packing contiguous to said second layer of packing and securing said third layer in a position 90° rotated from said second layer to further limit the bypass of liquids therearound.
45. A method of liquid-liquid extraction for a first, heavy phase liquid and a second, light phase liquid flowing countercurrently in a substantially vertical column constructed with a series of axially alternating transverse calming and mixing sections, said method comprising the steps of:
flowing a first, heavy phase liquid and a second, light phase liquid countercurrently through said mixing sections for agitation therein;
flowing said first and second liquids countercurrently through structured corrugated packing disposed in said calming sections, said corrugated packing comprising contact plates disposed in generally face-to-face relationship within said calming section;
collecting said light phase liquid from an upper region of said column; and collecting said heavy phase liquid from a lower region of said column.
flowing a first, heavy phase liquid and a second, light phase liquid countercurrently through said mixing sections for agitation therein;
flowing said first and second liquids countercurrently through structured corrugated packing disposed in said calming sections, said corrugated packing comprising contact plates disposed in generally face-to-face relationship within said calming section;
collecting said light phase liquid from an upper region of said column; and collecting said heavy phase liquid from a lower region of said column.
46. The method as set forth in claim 45 and including the step of dispersing said light phase liquid in a counterflowing, continuous heavy phase liquid.
47. The method as set forth in claim 46 and including the step of dispersing said heavy phase liquid in a counterflowing, continuous light phase liquid.
48. The method as set forth in claim 45 and including the step of providing said structured packing, and column areas which are in contact with said liquids with plastic surfaces.
49. The method as set forth in claim 45 and including the step of flowing said first and second liquids between corrugated plates with smooth, unperforated surfaces.
50. The method as set forth in claim 45 and including the step of flowing said first and second liquids through at least two axially stacked layers of corrugated packing within at least one of said calming sections.
51. The method as set forth in claim 50 and including the step of rotating said second layer of packing 90° relative to said first layer of packing of said two axially stacked layers to enhance the edge sealing between said packing layers and said column to limit the bypass of liquids thereaound.
52. The method as set forth in claim 51 and including the steps of mounting a third layer of packing contiguous to said second layer of packing and securing said third layer in a position 90° rotated from said second layer to further limit the bypass of liquids therearound.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US52958995A | 1995-09-18 | 1995-09-18 | |
| US08/529,589 | 1995-09-18 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2232382A1 true CA2232382A1 (en) | 1997-03-27 |
Family
ID=24110523
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002232382A Abandoned CA2232382A1 (en) | 1995-09-18 | 1996-08-12 | Agitated-packed extraction column |
Country Status (9)
| Country | Link |
|---|---|
| KR (1) | KR19990045745A (en) |
| CN (1) | CN1201400A (en) |
| AR (1) | AR003544A1 (en) |
| AU (1) | AU6844396A (en) |
| BR (1) | BR9610523A (en) |
| CA (1) | CA2232382A1 (en) |
| CO (1) | CO4560416A1 (en) |
| TW (1) | TW325413B (en) |
| WO (1) | WO1997010886A1 (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| MX2014009743A (en) * | 2012-02-14 | 2014-11-13 | Sulzer Chemtech Ag | An extraction column and process for use thereof. |
| SG11201503995YA (en) * | 2012-12-21 | 2015-08-28 | Sulzer Chemtech Ag | A liquid-liquid extraction system and process for use thereof |
| RU2521966C1 (en) * | 2013-01-09 | 2014-07-10 | Федеральное государственное бюджетное образовательное учреждение высшего профессионального образования "Белгородский государственный технологический университет им. В.Г. Шухова" | Bubble extractor |
| RU2528678C2 (en) * | 2013-01-09 | 2014-09-20 | Федеральное государственное бюджетное образовательное учреждение высшего профессионального образования "Белгородский государственный технологический университет им. В.Г. Шухова" | Multi-stage bubbling extractor |
| EP2886175A1 (en) | 2013-12-18 | 2015-06-24 | Sulzer Chemtech AG | Counter-current extraction column with an agitating internal and a static internal |
| CN106669225A (en) * | 2017-01-12 | 2017-05-17 | 清华大学 | Composite impulse extracting tower |
| CN109912045B (en) * | 2019-03-22 | 2021-08-27 | 河海大学 | Permeable reactive barrier |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2493265A (en) * | 1947-11-26 | 1950-01-03 | Hoffmann La Roche | Extraction apparatus |
| US5185106A (en) * | 1990-11-27 | 1993-02-09 | Glitsch, Inc. | Tower packing with small louvers and mixing method |
| US5219533A (en) * | 1991-11-18 | 1993-06-15 | General Electric Company | Apparatus for solvent extraction process |
-
1996
- 1996-08-12 BR BR9610523A patent/BR9610523A/en not_active Application Discontinuation
- 1996-08-12 KR KR1019980701988A patent/KR19990045745A/en not_active Application Discontinuation
- 1996-08-12 WO PCT/US1996/012997 patent/WO1997010886A1/en not_active Application Discontinuation
- 1996-08-12 CA CA002232382A patent/CA2232382A1/en not_active Abandoned
- 1996-08-12 CN CN96198114A patent/CN1201400A/en active Pending
- 1996-08-12 AU AU68443/96A patent/AU6844396A/en not_active Abandoned
- 1996-09-09 TW TW085111006A patent/TW325413B/en active
- 1996-09-10 AR ARP960104296A patent/AR003544A1/en unknown
- 1996-09-18 CO CO96049681A patent/CO4560416A1/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| AR003544A1 (en) | 1998-08-05 |
| CO4560416A1 (en) | 1998-02-10 |
| CN1201400A (en) | 1998-12-09 |
| MX9802125A (en) | 1998-08-30 |
| AU6844396A (en) | 1997-04-09 |
| TW325413B (en) | 1998-01-21 |
| WO1997010886A1 (en) | 1997-03-27 |
| BR9610523A (en) | 1999-07-06 |
| KR19990045745A (en) | 1999-06-25 |
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