DE1231173B - Mixing and separating centrifuge - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. α .:

B 04b

German class: 82b-l '

Number: 1231173

File number: S 79877 HI / 82 b

Filing date: June 12, 1962

Opened on: December 22nd, 1966

The invention relates to a mixing and separating centrifuge which is used to at least two to bring partially immiscible main fluids in countercurrent into contact with one another, and within whose full jacket centrifugal drum concentric cylindrical inserts with progressively larger radial distance from the drum axis are arranged, the one main fluid via an axial Channel in the drum shaft and one or more radial tubes is introduced into an intermediate stage and the main fluid from the drum wall via radial channels on the end faces of the centrifugal drum or from the inner cylindrical insert through separate axial channels in the drum shaft be discharged. Such centrifuges, in which one fluid of the dissolving action of the other fluids exposed in order to wash out or extract one or more constituents, are z. B. in the solvent refining of petroleum fractions, such as in the extraction of petroleum using phenol or furfural as a solvent, or when cleaning chemical or pharmaceutical products Products used. Usually both fluids are liquid. However, in some use cases the fluid with the lower density can be gaseous or vaporous.

It is known to introduce an auxiliary fluid into the centrifugal drum in addition to the main fluids. Usually the auxiliary fluid is used together with the main fluid, with which it is immiscible, as a dispersion inserted into the spin drum. So z. B. in the extraction of lubricating oil with phenol in In some cases, in order to create a reflux, water is introduced as an auxiliary fluid together with the oil. The water reduces the dissolving power of the phenol in the contact stage in which the fresh oil phase and the last extraction phase are in contact.

It has now been found that a more effective utilization of the reflux formed by the auxiliary fluid achieved when the auxiliary fluid is at a stage other than the feed stages for the main fluids, e.g. a stage lying between these feed stages or beyond these feed stages will.

The aim of the invention is therefore to design the known mixing and separating centrifuge so that the Auxiliary fluid fed to a contact stage other than that used for feeding in the main fluids can be without a special inlet duct leading into the centrifugal drum for the Auxiliary fluid is provided.

Mixing and separating centrifuge

Applicant:

Shell International Research

Maatschappij N.V., The Hague

Representative:

Dr.-Ing. F. Wuesthoff, Dipl.-Ing. G. Pulse and
Dipl.-Chem. Dr. rer. nat. E. Frhr. v. Bad luck man,
Patent Attorneys, Munich 9, Schweigerstr. 2

Named as inventor:

Joseph Walton Burdett, Houston, Tex. (V. St. A.)

Claimed priority:

V. St. v. America June 13, 1961 (116752) -

In the case of the mixing and separating centrifuge of the type described above designed according to the invention is arranged within the centrifugal drum at least one radial cylindrical separation chamber into which Via an axial inlet channel provided in the drum shaft and at least one radial channel with a radial orifice, a dispersion of the other fluid and one that is essentially immiscible with this Auxiliary fluid of different density is introduced, and has the separation chamber separate radially spaced outlets, via which the separated fluids in different radial distances from the drum axis supplied to the concentric cylindrical inserts will.

The inventive design of the mixing and separating centrifuge has the consequence that in the separation chamber the auxiliary fluid is centrifuged out of the dispersion of main fluid and auxiliary fluid, after which the Main fluid from the separation chamber into a feed stage and the separated auxiliary fluid from the separation chamber is introduced into another contact stage. The outlet for the auxiliary fluid is expedient from the separation chamber essentially unthrottled, while the outlet for the main fluid is restricted is.

A particularly advantageous embodiment of the mixing and separating centrifuge according to the invention is

60 »748/252

characterized in that the cylindrical channel of the separation chamber si & lfi extends through a plurality of inserts and distributed along its wall and each associated with different inserts has standing outlets and that a rotatable cylinder with radial openings for opening and Closing selected passages is provided to insert into at least one of each other separate fluids is introduced to choose.

Preferably, the radial mouth connected to the radial channel is arranged such that it forms an annular channel with the wall of the channel at the level of the inner outlet.

The invention can be used both in the case in which the auxiliary fluid in admixture with the lighter than also in the case in which it is mixed with the heavier main fluid in the centrifugal drum is introduced. In the first case, the main fluid and the auxiliary fluid are from the Drum axis fed radially further outward contact steps, while in the second case are introduced in stages closer to the drum axis.

The invention is illustrated below with reference to schematic drawings of exemplary embodiments explained in more detail, in which the auxiliary fluid in admixture with the lighter main fluid in the centrifugal drum is introduced.

Fig. 1 is a perspective view of a mixing and separating centrifuge according to the invention, partially on average,

Fig. 2 is an axial section through the centrifugal drum,

3 shows a partial section from FIG. 2 on an enlarged scale Scale and

F i g. 4 one of the F i g. 3 corresponding cut with changes.

The number of inserts and holes shown in the drawings is smaller than usual in practice, whereby their dimensions have also been changed for clarity.

The mixing and separating centrifuge for bringing fluids into contact comprises a substructure 11, on which the shaft 12 of a centrifugal drum 13 is mounted. As in Fig. 1 shown in dashed lines the centrifugal drum has a stationary housing with an upper and a lower section 14 or 15. The drum is driven by a belt pulley 16. The shaft 12 has two in the area the centrifugal drum interrupted axial bores, which each have a coaxial tube 17 or 18 included, so that two concentric channels are formed on each side of the shaft, the tubes 17 and 18 for the inflow of fluids of greater or lesser density and the annular channels 19 and 20 serve to remove the fluids of greater and lesser density brought into contact. The inlet ends the tubes 17 and 18 are each with bores in fixed shaft extensions 21 and 22 an inlet opening 23 or 24 in connection, with the separation of the inflowing and outflowing Fluid sealing means 25 and 26 are provided. The annular channels 19 and 20 each have a connection with the outlet lines 27 and 28.

The centrifugal drum 13 comprises a hub 9 connected to the shaft 12, two attached to the hub annular side walls 29 and 30 and a cylindrical peripheral wall 31. Inside the centrifugal drum are at a sufficient short distance from the side walls for a flowing liquid 29 and 30 intermediate walls 32 and 33 attached to the hub 9, which has an annular gap on the outer circumference to the peripheral wall 31 leave. Between the partitions 32 and 33 there are concentric cylindrical ones Inserts 34 arranged at a progressively greater radial distance from the drum shaft,

ίο which has a large number of annular contact cells or form levels. The radial dimensions of these cells are usually between 5 and 75 mm.

Fresh fluid of greater density is applied through the tube 17 via one or more radially Tubes 35 with channels 36 of an intermediate stage of the centrifugal drum, but preferably not the innermost contact cell supplied. These radial tubes 35 are inserted into the inserts with a tight fit. Fresh lower density fluid together with an auxiliary fluid flows in the form of a dispersion in radial direction Contact steps further out from the tube 18 into the shaft 12 via a corresponding number drilled channels 39 to one or more radial channels 38 serving as a separation chamber, in which the dispersion is separated again by centrifugal action. The fluid brought into contact The lower density flows out of the contact step immediately surrounding the hub 9 via one or more Openings 37 made in the hub and shaft 12 and the annular channel 19 through the outlet 27 from.

The brought into contact fluid of greater density flows from the directly to the peripheral wall 31 adjacent space through a radial gap 40 between the side walls 30 and 33 and 29, respectively and 32 and through openings 41 and 41a made in the hub 9 and in the shaft 12, respectively, in the annular Channel 20 and from this through the outlet 28 from. The fluid coming from the radial gap 40 flows through an axial channel 42 milled into the hub to the passage opening 41a and further to the channel 20. To reduce the peripheral speed of the fluid flowing radially inward support, can within the radial column 40 and 40 a generally extending radially, such as Turbine blades curved blades 43 may be provided.

The inserts 34 have perforations of any known or suitable type, e.g. B. as in Fig. 3 holes shown 44. You can for example also for the separate flows of the two phases form two different sentences, while in the continuous phase they form one negligible Cause pressure drop. Although only one radial feed pipe 35 and one radial channel 38 with separation chamber 50, 51 are shown for centrifugal separation, any number of them can be used for Use to ensure vibration-free operation at high speed are arranged so that the centrifugal drum is statically and dynamically balanced.

The wall of the separation chamber 50, 51 points to the exit of the supplied fluids in the desired Contact steps have lateral passages 45 and 46 consisting of multiple lateral openings for each step can be formed. So z. B. the passage 45 forming the connection with the openings Contact step 47 between the two outermost inputs

Sets 34 α and 34 b produce while the passage 46 is so that it lets the fluid into the cell 48 between the inserts 34 d and 34 e. In this embodiment, it is desirable to restrict the passage 46 and provide a large passage 45. In the embodiment shown, a deflecting sleeve 49 with a radial opening is mounted in the separation chamber opposite the passage 46 and extends in front of and over the passage 46 at a distance from the pipe wall in order to form an annular channel 50.

When the device z. B. for the solvent extraction of a lubricating oil with phenol as the selective Solvent is used, this solvent is passed through the pipe 17 and an oil-water dispersion introduced through the pipe 18 each with the appropriate pressure and the centrifugal drum in rotation offset. The oil-water dispersion flows radially outwardly through tube 38 and becomes, like in Fig. 3 shown separated by centrifugal action, whereby a water layer forms outside a boundary layer I. Inside the ring channel 50 oil accumulates. The water and oil enter separately via the respective passages 45 and 46 the contact stages 47 and 48 a. The deflection sleeve 49 prevents the oil-water dispersion through the Passage 46 flows off immediately.

In order to regulate the separate drainage of oil and water from the separation chamber, various Arrangements are applied. In the arrangement shown, the passage 45 is unthrottled and large enough to be negligible in the water flow into the return flow section of the centrifugal drum create small pressure drop; the openings forming the passage 46 are for restriction the flow rate to one with the fed via the line 18 into the centrifugal drum Oil volume of the same size, however, throttled.

Oil and solvent countercurrently flow through the individual contact cells between the inserts 34, passing through the holes 44. The raffinate phase, which mainly consists of oil, is discharged via the openings 37 and the channel 19. The steps lying radially outside the contact step 48 form the return flow section. The solvent phase which flows from cell 48 to cell 47 is mixed with water in the latter, whereby the dissolving power of the phenol is reduced and part of the washed-out oil is released as reflux; this moves radially inwards. The solvent extraction phase is removed from the step located directly inside the circumferential wall 31 via the radial gaps 40 and 40 a, the openings 41 and 41 ″ and the annular channel 20.

The modification of the separation chamber shown in FIG. 4 makes it possible to change the stage to which the oil is fed and / or the size of the oil passages 46. The channel 38 a has large openings 45 which, as in the embodiment described above, form the passage for the water. However, it has a plurality of openings 46 a, 46 b, 46 c, 46 d, each of which is in communication with different contact cells. Inside the tube 38 a there is a rotatable cylinder 52 in which the deflecting sleeve 49 is attached and the several openings to be brought into congruence with the openings 45

53 and several smaller openings 54 a, 54 b, 54 c,

54 d has which to cover the openings 46 a

to 46 rf are offset axially and at an angle to one another in such a way that only one opening is in congruence at a certain position of the cylinder 52. In the drawing, the openings 54 if and 46 d are in congruence. The position of the openings 53 is chosen so that the passage 45 is open in all positions. At the end of the cylinder 52, an end plate 55 designed as a flange is attached, which fits into a receptacle located in the outer centrifugal drum wall 31 and is held in place by a screw plug 56. In order to secure the cylinder against rotation, the annular surfaces of the flange 55 and the circumferential wall 31 in contact with one another can angswand 31 with locking devices, such as. B. the corrugated toothing denoted by 57 may be provided.

It can be seen that the stage in which the centrifuged oil is to be introduced through the Angular adjustment of the cylinder 52 can be selected. In the embodiment shown, this is achieved without changing the water-absorbing level. Because the cylinder 52 is easily replaceable is, it can be exchanged for a cylinder without any special effort, which is the for a certain oil flow rate suitable oil outflow openings having. This can also be done when the feature of attachment of several oil outflow holes along the pipes is absent.

In the above example, a case has been described in which the centrifuge supplies the auxiliary fluid (water) is supplied in admixture with the main fluid with lower density (oil) and the auxiliary fluid a Has a density between that of the main fluid (oil) mixed in and that of the mixed fluid The main fluid lies outside the phase opposing the separation zone, d. H. the extracted, mainly phenolic phase. For the sake of brevity, the last-mentioned phase will be the »outer Phase «. When the solvent has a lower density than the liquid to be extracted possesses, the auxiliary liquid counteracting the solvent can also the main fluid of greater density can be added. The separation chamber is then arranged so that it is in close proximity to the centrifugal drum axis feeds located contact stages. Furthermore, the density of the auxiliary fluid can be equal to the density of the external Phase, or it may be the density of the outer phase between that of the auxiliary fluid and that of the admixed main fluid lie. In the latter case, the separation zone is located within the separation chamber by itself in accordance with the densities, so that a throttling of the passage 46 is not required.

The mixing and separating centrifuge would not work as described if the density of the mixed Main fluid lies between the density of the auxiliary fluid and that of the outer phase. The centrifuge would, however, still be suitable for supplying the auxiliary fluid to a stage that is between the two with the main fluids fed stages.

Claims (3)

Patent claims: 1. Mixing and separating centrifuge, which is used to at least partially immiscible two Bring main fluids in countercurrent into contact with each other, within their full jacket Centrifugal drum concentric cylindrical inserts are arranged with progressively greater radial distance from the drum axis, the one main fluid being introduced into an intermediate stage via an axial channel in the drum shaft and one or more radial tubes and the main fluid from the drum wall via radial channels on the end faces of the drum Centrifugal drum or from the inner cylindrical insert through separate axial channels in the drum shaft, characterized in that at least one radial cylindrical separating chamber (50, 51) is arranged inside the centrifugal drum (13), into which one in the drum shaft (12) provided axial inlet channel (18) and at least one radial channel (38) with radial mouth (49) a dispersion of the other fluid and an auxiliary fluid of a different density, which is essentially immiscible with this, is introduced, and that the separation chamber is separated radially at a distance from one another Outlet e (45, 46) , via which the fluids separated from one another are fed to the concentric cylindrical inserts (34) at different radial distances from the drum axis. 2. Centrifuge according to claim 1, characterized in that the outlet (45) for the auxiliary fluid from the separation chamber (50, 51) is essentially unthrottled and the other outlet (46) is throttled. 3. Centrifuge according to claim 1, characterized in that the cylindrical channel (38 d) of the separation chamber (50, 51) extends through a plurality of inserts (34) and distributed along its wall and each with different inserts (34) communicating outlets (46a to 46 d) and that a rotatable cylinder (52) with radial openings (54 α to 54 d) for opening and closing selected passages is provided in order to use the insert into which at least one of the fluids separated from one another is introduced Select. 4- centrifuge according to claim 1, characterized in that that the mouth (49) connected to the channel (38) is arranged such that it is level with the inner outlet (46) with the Wall of the channel (38) forms an annular channel. Considered publications:
German Auslegeschrift No. 1037 417;
U.S. Patent No. 2,857,326. 1 sheet of drawings 609 748/252 12.66 © Bundesdruckerei Berlin