Static Internal, Use of One or More Static Internal, Agitated Liquid-Liquid Contactor and use of an Agitated Liquid-Liquid Contactor

Abstract

A static internal (1) embodied so as to be suitable for improving a contact, heat transfer or mass transfer between the liquids in an agitated liquid-liquid contactor (3) lacking calming sections and having an metallic agitated internal (2). The surface energy of the static internal (1) is <40, preferably <30, more preferably <25, most preferably <20 mN/m.

Claims

1-16. (canceled)

17. An agitated liquid-liquid contactor lacking calming sections and comprising a metallic agitated internal and a static internal embodied so as to be suitable for improving one of a contact, a heat transfer and a mass transfer between liquids having a continuous organic phase and a dispersed aqueous phase in an agitated liquid-liquid contactor lacking calming sections, such that the liquid contactor has only active zones and no passive zones and having a metallic agitated internal, wherein the surface energy of the static internal is <40 mN/m.

18. The agitated liquid-liquid contactor according to claim 17, whereby the agitated liquid-liquid contactor is adapted for the flow of liquids therein, whereby the liquids flow in a counter-current flow of streams and said agitated liquid-liquid contactor comprises: a substantially vertical column having a central axis therethrough, an agitated internal disposed within said agitated liquid-liquid contactor, a first outlet for a first fluid and a second inlet for a second fluid located in an upper area of the column, and a second outlet for the second fluid and a first inlet for a first fluid located in a lower area of the column.

19. The agitated liquid-liquid contactor according to claim 17, wherein the agitated liquid-liquid contactor is one of a reaction, a extraction and a mass transfer column.

20. The agitated liquid-liquid contactor according to claim 17, wherein the agitated liquid-liquid contactor is one of a RDC column, a Khni column, a QVF-Rhrzellen-Extraktor and a Scheibel column.

21. The agitated liquid-liquid contactor according to claim 17, wherein the agitated internals are made of metal.

22. A method for using agitated liquid-liquid contactor of claim 17, comprising using the agitated liquid-liquid contactor of claim 24 in one or more of a contact, a heat transfer and a mass transfer process.

23. The use of an agitated liquid-liquid contactor according to claim 22, wherein the use is a liquid-liquid extraction process.

24. The use of an agitated liquid-liquid contactor according to claim 22, wherein the liquid-liquid extraction process comprises two phases and the two phases have an interfacial tension of at least 1 mN/m,.

25. The use of an agitated liquid-liquid contactor in accordance with claim 22, wherein one phase is an aqueous phase and a second phase is an organic phase have an interfacial tension of 10-30 mN/m.

26. The use of an agitated liquid-liquid contactor in accordance with claim 22, wherein the static internal has a static contact angle >30 degree with a dispersed phase.

Description

[0040] The invention will be explained in more detail in the following both in an apparatus respect and in a process engineering aspect with reference to embodiments and to the drawing. There are shown in the schematic drawing:

[0041] FIG. 1 schematically shows a picture of a state of the art agitated liquid-liquid contactor;

[0042] FIG. 2 schematically shows a detailed drawing of a first embodiment of the agitated liquid-liquid contactor;

[0043] FIG. 3 schematically shows a detailed drawing of the static and agitated internals in accordance with the present invention;

[0044] FIG. 4 schematically shows a picture of the agitated liquid-liquid contactor in accordance with the present invention.

[0045] Referring to FIG. 2 there is shown schematically a detailed drawing of a first embodiment of the agitated liquid-liquid contactor. The agitated liquid-liquid contactor 3, for instance a column or a tower, has a vertical cylindrically shape closed at top and bottom. Mounted centrally through the entire length of the contactor 3 along an axial centrally axis A is an agitated internal 2, a rotatable shaft 2 seated in top bearing (not shown). The shaft 2, 23 extends through a bearing in the top of the contactor 3 for connection with a driving means, in particular a variable speed drive motor 9 disposed thereabove. Mounted on the rotatable shaft 2, 23, at spaced intervals, are radial horizontally extending further agitated internals 2, in particular stirrers, turbines, discs or agitators. The agitated internals 2 are preferably turbine type agitators with fins or blades 22 and guiding plates (not shown on the drawing) along the periphery of a rotatable horizontal plate 21. The number of fins 22 on-each agitator 2 may vary. Two to eight, preferably four to six, fins 22 are conveniently used. The fins or blades 22 have no pitch so as to impart only horizontal flow to the fluids. Rotation of the agitators in each section is effected by coupling the shaft 2, 23 on which the agitated internals 2 are mounted to a drive motor 9 through a mechanical gear (not shown). The agitated liquid-liquid contactor 3 is preferably divided into a section 10. In this particular side elevational, cross-sectional view, the sections 10 are shown in less detail. Each section 10 is limited and defined by two static internals 1, the static partition plates 1, 13. A height and therefore the section 10 is defined by a distance sleeve 11. Each section 10 is separated from the adjacent section by static partition plates 1, 13 that can be mounted against the contactor wall 4. An outside diameter of static partition plates 1, 13 is approximately the same as an inside diameter of the contactor 3.

[0046] These annular static partition plates 1, 13 are positioned above and below the agitated internals 2 in each section 10 and control the flow of the liquids. The static partition plates 1, 13 have a central opening to accommodate the rotating shaft 2, 23 and are mounted in the central zone along the axis A of the contactor 3. In other typical embodiments of the invention the partition plates 1, 13 have additional perforations. Sufficient clearance is maintained in the central opening and in the vicinity of the contactor wall 4 so as to provide a free area for smooth flow of liquid around the plate 1, 13 in the manner illustrated in FIG. 2. The static partition plates 1, 13 may be installed on vertically extending distance sleeve 1, 12. The contactor 3 is equipped with a first outlet 5 for a first fluid and a second inlet 6 for a second fluid located in an upper area of the contactor 3 and a second outlet 7 for the second fluid and a first inlet 8 for a first fluid located in a lower area thereof. Additional liquid inlets or outlets may be inserted at any point in the column, if desired. In addition, access ports may also be inserted at appropriate points in the top or side walls of the contactor 3 in any number desired. Sight glasses and liquid level gauges (not shown) may also be included in the structure. The contactor 3 can be constructed in sub-assembly units which are joined by flanges. The invention, however, is not restricted to the particular combination of structural features illustrated in each of the figures.

[0047] FIG. 3 schematically shows a detailed drawing of the static and agitated internals in accordance with the present invention. FIG. 3 substantially corresponds to FIG. 2. FIG. 3 shows, mounted on the rotatable shaft 2, 23, at spaced intervals, are radial horizontally extending further agitated internals 2, in particular stirrers or agitators. The agitated internals 2 are preferably turbine type agitators with fins or blades 22 along the periphery of a rotatable horizontal plate 21. The agitated liquid-liquid contactor 3 is divided into a section 10, shown in detail. Each section 10 is limited and defined by two static internals 1, the static partition plates 1, 13. The height and therefore the section 10 is defined by a distance sleeve 11. Each section 10 is separated from the adjacent section by static partition plates 1, 13.

[0048] The agitated internals 2 and the distance sleeves between the partition plates are in the region of the vortex flow pattern. So both parts are well flown around with the continuous phase. If droplets start to wet these parts they will be flushed away. To maintain the droplet dispersion inside the extraction column, the static internals should have a low wettability and large contact angle with the dispersed droplet phase. Thus the phases in the present invention are opposite in terms of the nature of the carrier and disperse phases (water versus organic) relative to the material of construction of the static internals versus those in GB '602, in which the organic disperse phase should coalesce on and wet the Teflon internals. In the process of the present invention, the disperse aqueous phase should be prevented from wetting the plastic (fluoropolymer) static internals. Merging this requirement with the above mentioned wettability of plastic and metal, a dispersion containing organic droplets in a continuous aqueous phase should be applied in a column with metal internals. For a dispersion of aqueous droplets in a continuous organic phase, the static parts should be made of plastic.

[0049] Referring to FIG. 4, FIG. 4 shows a picture of the agitated liquid-liquid contactor in accordance with the present invention. FIG. 4 relates to the cases when an aqueous phase is dispersed in a continuous organic phase. The liquids applied in these trials were pure technical grade dichloromethane as the continuous phase and an aqueous feed stream containing water >20 wt. % of an organic component which is soluble in dichloromethane and >20 wt. %. of an inorganic product. The flow rate of the dichloromethane was approx. 20 kg/h, the flow rate of the aqueous feed was approx. 10 kg/h in both set ups. The figure show close observation of trials on a 60 mm pilot column. The partition plates 1, 13 are the main part to promote wetting and coalescence. To verify the impact of these partitions 1, 13 plates, the metal static internals 1 are replaced by plastic static internals 1. Astonishingly, by changing the static internals 1 the wetting behavior is substantially improved. Advantageously, the static internals 1 are easy to replace without having to tackle the challenges of plastic agitated internals 2. FIG. 4 shows a dispersion of aqueous droplets in an organic phase using static internals 1 made of plastic. It is observed that almost no droplet sticks to the plates 1, 13 and the flow pattern inside the column is visually improved.