Conduited axial shaft for a centrifugal liquid extractor and phase separator

BACKGROUND OF THE INVENTION

This invention relates generally to improvements in centrifugal countercurrent and cocurrent exchange devices of the type disclosed in United States Patent No. 3,217,980, issued Nov. 16, 1965, and entitled “Centrifugal Countercurrent Exchange Device With Fully Adjustable Apertures”; United States Patent No. 3,114,706, issued Dec. 17, 1963, and entitled “Centrifugal Countercurrent Exchange Device With Interchangeable Disc Columns”; United States Patent No. 3,292,850, issued Dec. 20, 1966, and entitled “Phase Separator Convertor and Adjustable Liquid Feed and Discharge Means for Centrifugal Countercurrent Exchange Devices”; and United States Patent No. 3,350,001, issued Oct. 31, 1965, and entitled “Method for Fluid Extraction and Apparatus Therefor.” More particularly, the invention pertains to improvements in the axial shaft whereby the passageways by means of which the liquids are introduced to and removed from the rotor are so designed and positioned as to enable the liquids to be uniformly distributed linearly across the full width of the rotor even though the dimensions of said rotor may be as wide as 60 inches or more.

As disclosed in the aforementioned patents (see FIG. 1 in Patent Nos. 3,292,850 and 3,350,001) the axial shafts of the devices were formed with liquid influent passage ways for the heavy and light liquids respectively extending inwardly from the ends of the shaft and approaching the center thereof. The passageways terminated in perpendicularly formed passageways extending radially to the circumferential surface of the shaft and communicating with liquid distribution tubes extending radially from the shaft through the separator bands of the rotor to the periphery thereof. The influent conduit passageways were surrounded by a concentric liquid effluent passageway by means of which the light and heavy processed liquids were removed from the device. The influent passageways normally extended inwardly beyond the concentric effluent passageways and communicated at their respective ends with the liquid distribution passageways and tubes, their terminii or end positions determined the linear point in the width of the rotor at which the liquids were introduced therein. Said point of introduction was limited to one per influent tube since the influent conduit passage25 ways were enveloped in concentric effluent passageways. Stated otherwise, the influent passageways could be “tapped” for communication with the radial liquid distribution tubes only at one point, their inner terminii.

In the smaller diameter and narrower width rotors, introduction of the liquids at only one point across the width of the rotor was often sufficient, although variability and adjustability to accommodate different liquids and processes was limited. However, this was not acceptable in the larger width rotors since improper localized distribution of the influent phases or liquids resulted in low theoretical stage efficiency and channeling of the liquids to prevent proper contacting one with the other with resultant less than optimum extraction. Moreover, it was difficult, if not impossible, to introduce the heavy and light liquids in the same plane for maximum distribution.

SUMMARY OF THE INVENTION

To overcome the disadvantages mentioned hereinabove, the axial shaft is formed in three sections with the central section long enough to extend across the full width of the rotor. The central section may be welded between the two end sections or the adjacent ends of the several sections of the shaft may be formed with cooperating threaded portions enabling the central section to be readily removed or replaced by another section of another design selected to accommodate varying liquids or processes being carried out in the particular machine.

The central section of the shaft is formed with a plurality of liquid influent and effluent conduits extending inwardly from the ends of said section. Some of these conduits extend the full length of the section and others, especially the effluent conduits, extend inwardly only to the point where they communicate with effluent passageways communicating with the outer surface of the shaft and the effluent distribution tubes from the rotor. All of the axial shaft conduit passageways are independent one of the other; none of them are formed concentrically about one or the other. Thus, the influent conduit shaft passageways may be “tapped” at any point along their full length to communicate with liquid distribution tubes or other means for introducing the liquids into the rotor. Consequently, the liquids may be introduced uniformly and at equally spaced points along the entire width of the rotor, thereby insuring optimum distribution of the liquids throughout the entire width of the rotor.

It is, therefore, an important object of this invention to provide means for introducing and removing liquids from centrifugal liquid extractors and phase separators in such a manner as to overcome all of the disadvantages mentioned hereinabove.

It is another important object of this invention to afford axial shafts for the rotors of centrifugal cocurrent countercurrent exchange devices having influent and effluent liquid conduit means formed therein to insure uniform distribution of said liquids for the full width of the concentric bands of the rotor.

A further object of this invention is to provide liquid distribution means for devices of the character described insuring proper distribution of the influent phases whereby greater theoretical stage efficiency may be achieved, and channelling of the liquids may be substantially reduced or completely eliminated to insure optimum extraction or phase separation.

Still another object is to afford means enabling both

3,494,543 the heavy and light liquids to be introduced to the rotor on the same plane with the heavy liquid entering adjacent the shaft and the light liquid entering near the periphery of the rotor.

Still a further object of this invention is to afford a multi-section axial shaft in which one or more of the sections may be readily replaced with sections of other designs to accommodate various liquids and processes without necessitating replacement of the entire device.

With the foregoing and other objects in view which will appear as the description proceeds, the invention consists of certain novel features of construction, arrangement and a combination of parts hereinafter fully described, illustrated in the accompanying drawings, and particularly pointed out in the appended claims, it being understood that various changes in the form, proportion, size and minor details of the structure may be made without departing from the spirit or sacrificing any of the advantages of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

For the purpose of facilitating an understanding of our invention, we have illustrated in the accompanying drawings a preferred embodiment thereof, from an inspection of which, when considered in connection with the following description, our invention, its mode of construction, assembly and operation, and many of its advantages should be readily understood and appreciated.

Referring to the drawings in which the same characters of reference are employed to indicate corresponding of similar parts throughout the several figures of the drawings:

FIG. 1 is a sectional view of an axial shaft taken on the plane of line 2—2 in FIG. 3 of the drawings, viewed in the direction indicated and also showing fragmentary portions of a rotor, separating bands and liquid distribution tubes;

FIG. 2 is a longitudinal sectional view of the several sections of the shaft taken on the plane of line 2—2 in FIG. 3 of the drawings and showing merely fragmentary portions of the end walls of the rotor;

FIG. 3 is a cross-sectional view taken on the plane of line 3—3 in FIG. 1 of the drawings and viewed in the direction indicated;

FIG. 4 is a cross-sectional view taken on the plane of line 4—4 in FIG. 1 of the drawings and viewed in the direction indicated;

FIG. 5 is a cross-sectional view taken on the plane of line 5—5 in FIG. 1 of the drawings and viewed in the direction indicated;

FIG. 6 is a cross-sectional view taken on the plane of line 6—6 in FIG. 1 of the drawings and viewed in the direction indicated; and

FIG. 7 is a cross-sectional view taken on the plane of line 7—7 in FIG. 2 of the drawings and viewed in the direction indicated.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Directing attention to the several figures of the drawings particularly FIG. 1 thereof, reference numeral 10 indicates generally a fragmentary portion of a centrifugal countercurrent exchange device or phase separator in which is incorporated our improved conduited axial shaft indicated generally by reference number 12. Since the basic device 10 is generally of the type described in the aforementioned patents or well known in the prior art and does not per se comprise the specific subject matter of the invention, only so much thereof as is necessary for an understanding of the subject invention will be described in detail. The device 10 thus comprises a rotor, fragmentary portions of which are shown and indicated generally by reference numeral 14. The rotor is mounted on the shaft 12 and includes the end walls 16 and end plates 18. Within the rotor cavity separator bands 20 are posi tioned in spaced relationship with their end portions supported in grooves formed in the end plates 18. The separator bands are formed with aligned radial cavities designed to accommodate therein adjustable liquid feed and discharge means or tubes 22 viz: those described in the abovementioned Patent No. 3,292,850.

The rotor 14 is rigidly mounted on the shaft 12 for rotation therewith. The shaft 12 may be made of several sections including a pair of end sections 24 and 26 and a central section 28. As will be noted in FIGS. 1 and 2 of the drawings, the rotor end walls and end plates 16 and 18 respectively are rigidly connected as by welding to the right and left shaft end sections 24 and 26 respectively. The central shaft section 28 may be joined to the shaft end sections 24 and 26 by any suitable means as, for example, by welding as shown in the embodiment chosen for illustration herein. However, to make the central section 28 more readily replaceable, the end portions of the central section may be formed with screw threads and the inner end portions of the end sections may be formed with complementary screw threads so that the central section may be readily removed and replaced with another such section of different design for a purpose which will be disclosed as the description proceeds.

The end sections 24 and 26 of the shaft are formed with effluent and influent liquid conduit passageways connecting respectively with liquid sources and liquid discharge collecting means. Thus, referring to FIGS. 1 and 2 of the drawings, the right end shaft section 24 is formed with a central heavy liquid influent passageway 30 surrounded by a concentric light liquid influent passageway 32. The left end shaft section 26 is formed with a central heavy liquid effluent conduit passageway 34 surrounded by a concentric light liquid effluent conduit 36. It will be noted that the heavy liquid effluent passageway 34 extends to the end surface 40 of the shaft section 26 beyond the terminus of the light liquid effluent conduit 36. The purpose thereof will become apparent as the descrption proceeds. Similarly, the heavy liquid influent passageway 30 in the right end shaft section 24 extends beyond the end surface 38 and beyond the outer terminus of the light liquid influent conduit 32. Conduit 32 opens to the shaft end surface 38. Similarly, the purpose of this construction will become apparent as the description proceeds.

Turning now to the structure embodying the most important features of the invention, i.e. the central shaft section 28, particularly as illustrated in FIGS. 1 and 2 of the drawings. The shaft may be formed with recesses 42 and 44 in their respective end walls, said recesses adapted to accommodate therein complementary reduceddiameter portions 46 and 48 of shaft end sections 24 and 26, respectively. In the embodiment selected for illustration the sections are joined together at the points above described by welding. However, as mentioned above, the inner walls of the recesses 42 and 44 may be threaded and the outer walls of the reduced diameter portions 46 and 48 of the end sections 24 and 26 respectively may be complementarily threaded. Suitable coupling means may be provided to cooperate with the aforementioned threaded means to enable the central shaft section 28 to be readily removed and replaced by a similar section but of different design to accommodate various liquids and processes as desired.

Central shaft section 28 is formed with a plurality of liquid conduit passageways, each of which is independent of the other and some of which extend substantially the entire length of the section. Thus, a heavy liquid influent conduit passageway 50 opening to the bottom wall 52 of the recess 42 extends substantially the entire length of the section but terminates in spaced relationship with the bottom wall 54 of the recess 44. The heavy liquid influent conduit 30 of the end section 24 communicates directly with the conduit passageway 50 and is connected thereto in liquid-tight relationship as shown in FIGS. 1 and 2 of the drawings. A plurality of independent light liquid in3,494,543 fluent conduit passageways 56 likewise extend inwardly from recess surface 52 across the substantial length of the shaft section 28 but terminate in spaced relationship with the opposite recess wall 54 as shown in FIG. 1 of the drawings.

Communication between the light liquid influent conduit passageways 56 of the central section 28 and the light liquid inlet passageways 32 of the shaft end section 24 is accomplished by spacing the end wall 38 of the reduced diameter section 46 from the wall 52 of the recess 42 in the central shaft section 28. Thus, liquids flowing through the conduit passageways 32 may be distributed uniformly to the plurality of light liquid influent passageways 56 in the space provided by the abovedescribed construction.

The liquid conduits 50 and 56 communicate with the interior of the rotor and the liquid distribution means 22 by means of radially extending passageways such as 58 and 60, respectively; passageways 58 communicating the heavy liquid influent conduit 50 therewith and passageways 60 communicating the light liquid influent conduits 56 therewith. These passageways 58 and 60 may be formed at spaced intervals linearly along the entire length of the shaft section, the number of the same depending on the width of the rotor. This insures uniform distribution for the entire width of the rotor.

The removal of the liquids after they have been processed in the rotor may be accomplished by means which will now be described in some detail. The heavy liquid is removed by means of a plurality of heavy liquid effluent conduit passageways 62 extending inwardly and opening to the recess wall 54, as shown in FIG. 2 of the drawings. These conduit passageways 62 extend inwardly to approximately the center of the shaft 28 and communicate at their inner ends with radial passageways 64. The radial passageways 64 open to the inner end or bottom of the rotor 14.

As in the right end portion of the shaft, the left end reduced diameter portion 48 has its inner end surface 40 spaced from the adjacent surface 54 of the recess 44 leaving a liquid passageway by means of which the heavy liquid effluent conduit 34 of the end section 26 may communicate with the heavy liquid effluent conduits 62 of the central shaft section 28. Thus, the heavy liquids are readily removed from the rotor flowing through the radial passageway 64, the axial conduit 62 and the heavy liquid effluent conduits 34.

The light liquid is removed from the rotor by means of radial passageways 66 extending from the rotor cavity to the light liquid effluent concentric conduit 36 of the end shaft section 26, as shown in FIG. 1 of the drawings.

The flow of the various liquids both heavy and light, effluent and influent, is illustrated by arrows in the several figures of the drawings or should be readily apparent. Although the embodiment chosen for illustrations is designed for only two influent and two effluent liquids or phases, three or more influent or effluent phases may be accommodated by providing additional conduit passageways in the center and end sections of the shaft.

From the foregoing description and drawings, it should be apparent that we have provided a novel conduited axial shaft having means for introducing and removing liquids to or from the rotor of a centrifugal countercurrent exchange device and/or phase separator, uniformly at a plurality of intervals across the entire width of the rotor of said devices; the number and spacing of said intervals determined by the width of the rotor. This insures proper distribution of the influent phases resulting in maximum theoretical stage efficiency and minimum channeling of the liquids, thereby insuring optimum liquid extraction.

It is believed that our invention, its mode of construction and assembly, and many of its advantages should be readily understood from the foregoing without further description, and it should also be manifest that while a preferred embodiment of the invention has been shown and described for illustrative purposes, the structural details are nevertheless capable of wide variation within the purview of our invention as defined in the appended claims.