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Publication numberUS3279611 A
Publication typeGrant
Publication dateOct 18, 1966
Filing dateSep 15, 1964
Priority dateSep 17, 1963
Also published asDE1189467B
Publication numberUS 3279611 A, US 3279611A, US-A-3279611, US3279611 A, US3279611A
InventorsVon Rotel Julius
Original AssigneeVon Rotel Julius
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Centrifugal separator
US 3279611 A
Images(4)
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Description  (OCR text may contain errors)

Oct. 18, 1966 J, VON QT L 3,279,611

CENTRIFUGAL' SEPARAI'OR Filed Sept. 15, 1964 4 Sheets-Sheet 1 INVENTOR /I4'M m y MW A W r 4 Sheets-Sheet 2 Filed Sept. 15, 1964 III INVENTOR Oct. 18,1966 ON RQTEL v 3,279,611

CENTRIFUGAL SEPARATOR Filed Sept. 15, 1964 4 Sheets-Sheet 3 FIG.3 22 J ,4

INVENTOR I Oct. 18, 1966 J. VON ROTEL CENTRIFUGAL SEPARATOR 4 Sheets-Sheet 4 Filed Sept. 15, 1964 INVENTOF? United States Patent 3,279,611 CENTRIFUGAL SEPARATOR Julius von Riitel, Kirschbaumweg 118, Dortmund, Germany Filed Sept. 15, 1964, Ser. No. 396,538 Claims priority, application Germany, Sept. 17, 1963, R 36,131 17 Claims. (Cl. 210-330) The present invention relates to a centrifugal separator, and more particularly to a centrifugal separator for separating the sol-id crystalline fraction and the liquid fraction of sugar syrup.

Centrifugal separators serving this purpose are provided with screens through which the liquid fraction passes during the separation. An increase of the output of the separator can only be obtained by increasing the size and area of the screen. The area of the screen cannot be increased beyond a certain limit by increasing the diameter of the separator, since the resulting higher peripheral speed causes a greater centrifugal force, and greater stress on the material of which the screens and the separator drum are made. Due to this fact, sugar refining plants have to use a great number of centrifugal separators of limited diameter.

It is one object of the present invention to increase the effective screen area of a centrifugal separator without increasing the diameter of the rotor of the machine.

In the known centrifugal separator, a plurality of separator pockets are located between two circular end walls of a rotary drum. The separator pockets are not coaxial, and are attached by bolts to the end walls of the rotary drum so as to resist the outward action of the centrifugal force. In order to secure the walls of the separator pockets to the drum, reinforcing ribs must be provided on the separator pockets so that the circumferential extension of the separator pockets is increased whereby the number of separator pockets which can be positioned in a drum of limited diameter, is also limited.

A mathematical analysis of the centrifugal forces acting on the bolts of the prior art has proven that, assuming an economical minimum width of the screens in axial direction, for example about 200 mm., the bolts are subjected to a substantial bending stress which requires an increase of the bolt cross section and the use of hollow bolts requiring even more space which again results in an increase of the width of the separator pockets.

It is another object of the invention to mount separator means including screens in a rotary drum in such a manner that they abut each other and the peripheral wall of the drum only under the action of the centrifugal force.

Another object of the present invention is to provide a centrifugal separator with a plurality of separator means which are not secured by bolts or other attaching means to the separator drum.

Another object of the invention is to provide such an arrangement of separator means that a greater number of separator means including screens can be mounted in a drum having a certain diameter than in the constructions of the prior art.

Another object of the invention is to increase the output of the centrifugal separator having a given diameter as compared with the prior art constructions.

Another object of the invention is to utilize the increased etiiciency of a separator having a given relatively small diameter by providing screens having extremely fine perforations permitting the elimination of very fine solid crystalline particles.

In accordance with the present invention a plurality of separator means are located within a rotary drum in 3,279,611 Patented Oct. 18, 1966 "ice circumferentially adjacent positions and have outer ends abutting the peripheral wall of the drum and inner ends arranged in a circle. Each separator means includes a separator member forming a cavity and a screen closing the cavity. The screens and separator members are preferably curved and extend at angles to radial and tangential directions in relation to the axis of the drum. The inner ends of the separator means form an inner space in the drum into which the substance to be separated into a liquid fraction and solid fraction is supplied by stationary supply means, such as a pipe having a slot.

Since the minimum width of the separator means is determined by the dimensions of the separator, the diameter and circumferential extension of the inner space determines the number of separator means which can be mounted in a drum, considering that each inner end of each separator means has a certain circumferential minimum extension. The most favorable ratio between the diameter of the peripheral wall of the drum and of the circle along which the outer ends of the separator means are located, and the diameter of the circle along which the inner ends of the separator means are located is 2 to l.

A particular problem is the uniform distribution of the substance to be treated over the circular inner surface formed by the inner ends of the separator means.

It is known that in separators employing separator pockets the supplied substance is very suddenly accelerated from zero speed to the peripheral speed. In order to prevent damage to the crystalline solid fraction, it is not only desirable that the substance is accelerated to a circumferential speed corresponding to the circumferential speed of the inner ends of the separator means before the substance enters between the separator means, but it is also necessary that the supplied substance is uniformly distributed over the entire circumference of the inner ends of the separator means, and also over the axial extension of the same.

It is another object of the invention to overcome these difficulties, and to supply the substance to the central space within the inner ends of the separator means by a pipe having an axial slot extending over the entire axial length of the separator means. A related object of the invention is to cover the inner end face of each separator means by an inner projecting portion or tongue of the separator means leading in the direction of rotation in such a manner as to form an inlet slit.

In this construction of the present invention, the substance which is outwardly thrown through the slot in the supply pipe cannot directly enter into the cavities between adjacent separator means, but first impinges the end faces of the inner end portions of the separator means on which they are gradually accelerated and guided toward the screens of the separator means.

While this at first results in a delay of the flow of the substance, the continuously supplied substance impinges on the substance accumulated on the end faces so that a ring consisting of the substance is formed on the inner ends of a separator means which rotates with the same. The successively supplied substance is taken up by this ring and gradually accelerated while the substance enters the inlets between the separator means in a continuous flow at the peripheral speed of the inner end faces of the separator means and passes at such speed to the screens. In this manner, the cavities between separator means are closed by the accumulated substance so that no air can enter into the separator means and the fan elfect pro- (122532 by the separator means of the prior art is eliminated. The power required for driving the centrifugal separator according to the present invention is substantially reduced since a considerable percentage of the sup- 3 plied power may be consumed by moving air unnecessarily.

The gradual acceleration of the substance to the circumferential speed of the inner ends of the separator means is further improved by the provision of a plurality of guide vanes curved in accordance with a logarithmic spiral and rotating at a speed lower than the rotary speed of the drum and the separators. The guide vanes have inner ends closely spaced from the supply pipe and outer ends closely spaced from the inner ends of the separator means, and While the substance passes from the inner ends to the outer ends of the guide vanes, it is accelerated until the circumferential component of the substance substantially corresponds to the circumferential speed of the inner ends of the separator means. The circumferentially spaced guide vanes alsoeffect the division of the supplied substance into several streams and a uniform distribution of the substance over the inner ends of the separator means.

The inner end portions of the guide vanes are preferably curved in a direction opposite to the logarithmic curvature of the main portions of the guide vanes so that the gaps between the inner end of adjacent guide vanes can be reduced to a minimum whereby lumps of solid material present in the supplied substance are retained, and damage to the fine screens of the separator means is prevented.

Adjusting means in the form of a slotted tubular member surrounding the end portion of the supply pipe and the slot therein are advantageously provided for adjusting the amount of substance passing from the supply pipe into the inner central space in which the guide vanes are located. Particularly, when the separation of sugar syrup into a liquid fraction and a solid fraction is intended, a high percentage of particles is present which are so fine as to pass through the perforations of the screens. In order to separate such smallest solid particles together with larger particles, in accordance with the present invention, the angle of curvature of the screens and separator means is selected in such ,a manner that the component of the centrifugal force causing the transportation of the substance is smaller than the angle of friction of the solid fraction of the substance. Furthermore, rotary oscillations are produced in the rotary parts of the centrifugal separator which preferably are somewhat below the self-frequency of the rotary parts. The rotary oscillations 'are advantageously produced by electromagnetic means which are energized by currency pulses at the desired frequency of the oscillation.

Due to the self-locking effect of the angle of curvature of the screens, the larger solid particles, which have a greater mass, are deposited on the screens during the operation of the machine, and form a filtering layer which retains the finer particles and prevents passage of the same through the screens. The thus-retained larger and smaller particles which together form the solid fraction, are continuously and without relative displacement transported in a continuous manner out of the machine by the effect of the rotary oscillations to which the rotary system of the centrifugal separator is subjected.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing, in which:

FIG. 1 is a vertical axial sectional view illustrating one embodiment of a separator according to the invention;

FIG. 2 is a cross sectional view on anenlarged scale taken on line 11-11 in FIG. 1;

FIG. 3 is a fragmentary axial sectional view taken on line IIIIII in FIG. 2;

FIG. 4 is a fragmentary sectional view taken on line 1V-IV in FIG. 5;

FIG. 5 is a fragmentary cross sectional view illustrating a detail of FIG. 2 on an enlarged scale; and

FIG. 6 is a fragmentary sectional view taken on line VIVI in FIG. 5.

Referring now to the drawings, and more particularly to FIG. 1, a motor 41 has a shaft 42 carrying a pulley 43 having two pulley portions of different diameters re spectively connected by V-belts to pulleys 48 and 45 which are respectively secured to a shaft 37 and to a hollow shaft 2 surrounding shaft 37 and being mounted in bearings 2a of a support 50. The hollow shaft 2 carries a fixed flange 1 secured by screws, not shown, to a circular lateral wall 3 of a rotary drum 51 which includes another circular lateral wall 7 and a peripheral annular wall4 of cylindrical configuration around which annular ribs 5 extend. A circular flange 6 is penetrated by screws 9, schematically indicated by dash and dot lines, which hold the lateral wall 7 attached to the peripheral wall 4..

Lateral wall 7 has a central opening 8 concentric with the axis of shaft 2 and of the rotary drum 51.

Within the rotary drum 51, a plurality of separator means generally indicated by reference numeral 52. The general arrangement of the separator means 52 is best seen in FIG. 2, and two adjacent separator means 52 are shown in FIGS. 4 and 5.

Each separator means includes a curved wall whose curvature corresponds to a logarithmic spiral whose curvature extends at angles to radial and tangential directions with respect to the axis of the rotary drum. The. in-

wardly facing side of each separator wall 10 is eoncave and formed with grooves or channels 11 separated from each other by ridges 10a, as best seen in FIG. 4. The outwardly facing convex side of each separator wall 10 is provided at the axially spaced edges thereof with ridges 10b which have outer edges curved at the same curvature as walls 10, but whose circumferential height increases from the inner ends of the separator walls toward the outer ends of the same, as best seen in FIGS..

broken line has axially spaced edges resting on corresponding shoulders provided along the axially spaced edges of wall 10, as best seen in FIG. 4. The inner end of each screen 16 is formed as a hollow bead inserted into the recess of the thicker portion 12, and held in the same by inserted cylindrical plug 19. The outer end of each screen 16 may have a bar 16a secured thereto and abutting an abutment portion 20 provided at the outer end of each wall 10.

Due to the fact that each curved ridge 10b abuts the adjacent wall 10 of the adjacent separator means, the abutment portions 20 of the adjacent separator means are spaced from each other and define between each other an outlet 23. Outlets 23 are spaced from each other in circumferential direction, as best seen in FIG. 2,

and circumferentially spaced outlet openings in peripheral wall 4 register, respectively, with outlets 23.

Between each pair of adjacent separator. means 52,. a first cavity 54 is formed which has at the inner end.

drum, as best seen in FIG. 3, and has an outwardly located end terminating in a tubular Outlet means 22.

As best seen in FIG. 4 curved sealing members 40 are provided in the [first cavities 54 adjacent the ridges b to seal the cavities of adjacent separator means from each other. Sealing members 40 slightly project beyond the ridges 1%, as shown in FIG. 4 and abut corresponding shoulders on the adjacent wall 10.

As best seen in FIG. 3 the annular reinforcing ribs 5 which surround the peripheral annular cylindrical wall 4 cross the outlet openings or slots 24 in wall 4. In the regions of slots 24, the inner annular edges of the annular ridges 5 are inwardly tapered to form a blade-like edge 5a. The separator means 52 are completely identical, and may be manufactured by an injection molding process with exception of the screens 16 which are later attached. The complete set of separating means 52 is assembled to form a complete ring as shown in FIG. 2 and are clamped together in a package by clamping means engaging only the axial end portions of abutments 20. The inwardly directed pressure of the clamping means compresses the sealing members 40.

The clamped package of separator means is inserted into the interior of the drum formed by walls 3 and 4 after wall 7 has been removed. When the clamping device interferes with further axial insertion, it is removed, and the package of separator means fully inserted, whereupon wall 7 is attached by screws 9 to flanges 6 of the drum 51.

In the embodiment illustrated in FIG. 2, eighty separator means are provided. Each separator means abuts against the adjacent separator means in circumferential direction, and abuts the inner surface of the peripheral wall 4 with abutment portion 20, and more particularly with the outer abutment face of abutment portion 20 which has a cylindrical shape corresponding to the cylindrical inner surface of wall 4. The abutment between adjacent separator means takes place along the outer curved convex edges of ridges 10b and the corresponding curved edges of wall 10 of the adjacent separator means, as best seen in FIG. 4. Tongues 14 are held by the inner ends of ridges 10b in such a spaced relationship as to form very narrow inlet gaps 15 betwen each other. When the package of separator means is inserted into drum 51, the angular position must be carefully chosen so that the outlet slots 23 between adjacent abutment portions register with the outlet slots 24 in the peripheral wall 4 of the drum. After insertion of the package of separator means, screws 9 are not fully tightened, and in this condition, the drum is rotated so that the centrifugal forces acting on separator means urges the same outwardly and into abutting engagement with each other and with peripheral wall 4. When the separator means tightly abut each other, screws 9 are tightened so that the axial pressure exerted by wall 7 on ridges 10b provides sufiicient friction to prevent any relative turning movement between the package of abutting separator means and drum 51.

As best seen in FIG. 2, the inner ends of the separator means, and more particularly the tongues 14 which are located along a circle founding a central inner space 26 within the drum. The outer diameter of the inner space 26 is approximately one-half of the diameter of the peripheral annular wall 4 of drum 51. Assuming a certain circumferential extension of the inner ends of the separator means, and the smallest desired width of the inlet gaps 15, the diameter of the central inner space 26 is given. The surface of the screens should be as great as possible. In one preferred embodiment of the invention, the diameter of the peripheral annular wall is about 1,000 mm., and the diameter of the inner space 26 between 450 and 500 mm.

The substance to be separated into a liquid and solid fraction is supplied by pipe 25, and more particularly through an axial slot a leading into the inner space 26.

The circumferential speed of the inner end portions 14 is substantial, and if the substance were directly dropped from slot 25a onto the tongues 14, the crystals of the solid fraction may be damaged when the substance is accelerated from the zero speed prevailing in slot 25a to the circumferential speed prevailing at the inner ends of the separator means. In order to gradually accelerate the substance, and also to uniformly distribute the substance to all the inlet gaps 15 at the inner ends of the separator means, the present invention provides guide vanes 33 Within the inner space 26. Each guide vane is formed in accordance with a logarithmic spiral having an inclination of about 12. The guide vanes overlap each other, and are held together by two axially spaced circular discs 34 and 35 as best seen in FIG. 1. Disc 34 is secured to a flange 36 carried by shaft 37. As explained above, the pulleys on shafts 2 and 37 have different diameters so that shaft 2 is driven at the higher speed, and shaft 37 driven at a lower speed. Consequently, drum 51 rotates at a higher speed than the guide vanes 34, a preferred speed difference being 3%.

The inner end portion of each guide vane 33 is bent in a direction opposite to the direction of curvature of the main portion of the respective guide vanes 33 and extends into the proximity of the adjacent guide vane forming a narrow inlet gap 39 with the same. The width of the gap may be, for example, 3 mm. whereby lumps forming part of the substance supplied through pipe 25 and slot 25a having a greater dimension than 3 mm. are prevented from passing along the guide vanes to the separator means. Such lumps are retained by the gaps 39, and may be removed when the separator is stopped. In this manner, damage to the fine screens 16 by large lumps is prevented.

During operation, a substance containing a solid fraction and a liquid fraction is supplied through pipe 25 and passes through slot 25a in downward direction due to the action of gravity, since the guide vanes 33 are rotated by shafts 37, the substance impinges successively on the inner portions of all guide vanes 33 and moves along the same due to the action of the centrifugal force so as to enter through the inlet gaps 39 into the spaces between the outer portions of guide vanes 33 by which the substance is accelerated until its circumferential speed components corresponds substantially to the circumferential speed of the inner end portions or tongues 14 of the separator means 52 which rotate at the same higher speed as drum 51. The substance moving in outwardly direction impinges the overlapping tongues 14 which are so positioned that the substance deposited thereon is further accelerated in circumferential direction and moves outwardly along the same tending to pass into inlet gaps 15. At first, an amount of the substance is deposited in the form of a ring on the overlapping tongues 14 and rotates with the separator means 52 and drum 51. As additional substance is deposited on the ring of deposited material, it is accelerated gradually while at the same time the corresponding part of the material forming the deposited ring enters through inlet gaps 15 into the first cavities 54 formed between adjacent separator means as best seen in FIG. 5. The substance is urged by the centrifugal force to press against the respective screen 16 of the adjacent separator means and to move along the same in outward direction. During this travel, the liquid fraction is separated from the solid fraction and enters the second cavity 55, traveling along grooves 11 toward the outlet 21, while the solid fraction travels on the other side of screen 16 in cavity 54 and is discharged through the aligned outlets 23, 24.

As best seen in FIG. 1, the housing of the machine includes a collector portion 31 surrounding drum 51 so that solid material discharged from outlet openings or slots 24 will be received by collector housing 31 after having passed the blade-like inner edges of the annular ridges 5 which facilitate the outward movement.

The liquid fraction which has passed through a screen 16 in cavity 55 moves along the inwardly concave surface of the respective Wall until it reaches the outlets 21 from which it passes into the axial ducts 21a. Due to the action of the centrifugal force, the liquid fraction'moves toward the outwardly located end of the inclined ducts 21a and is discharged through outlets 22 which are surrounded by' a frusto-conical guide 27 secured to wall 3 of drum 51 and rotating with the same so that the centrifugal force causes movement of the liquid fraction along the inner frusto-conical surface of ring 27 until the liquid passes over the wider annular edge of ring 27 and into the collector housing portion 28 of the collector housing 29, the collector portions 28 and 31 being separated by walls. An outlet 30 is provided at the bottom of collector housing 28 through which the liquid is discharged. The solid part discharged into collector housing 31 drops through a corresponding opening 31a at the bottom of collector housing 31.

The inner end 25b of the supply pipe 25 may be surrounded by a sleeve, not shown, having an opening which can be aligned with slot 25a. When the sleeve is turned, a circumferential extension of the superimposed slots is reduced so that a smaller amount of the substance is supplied to the rotating guide vanes 33.

When the angle of curvature of the screen 16 is suitably chosen, the component of the centrifugal force acting to transport the substance along the screens is smaller than the friction angle of the solid fraction of the substance. If under such circumstances, the rotary drum 51 is subjected to rotary oscillations, preferably somewhat below the self-frequency of the rotating parts, even the finest solid particles are discharged together with larger solid particles. Such rotary oscillations may be obtained by electromagnetic means excited at the desired frequency of the oscillations.

It will be understood that each of the elements described above or two or more together, may also find a useful application in other types of centrifugal separators diifering from the types described above.

While the invention has been illustrated and described as embodied in a centrifugal separator provided with a plurality of separator means abutting each other and enveloping drums due to the action of the centrifugal force, it is not intended to be limited to the details shown, since various modifications and structural changes may be made Without departing in any way from the spirit of the present invention.

Without further analysis the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed and desired to be secured by Letters Patent is:

1. A centrifugal separator comprising, in combination, a rotary drum having an axis and a peripheral wall having outlet openings; a plurality of separator members, and a plurality of screen means alternately disposed in said drum in circumferentially adjacent positions abutting each other and forming alternating first and second cavities between each other, said screen means and separator members having inner ends forming inlets into said first cavities and having outer ends abutting said peripheral wall and forming first and second outlets from said first and second cavities, said screen means extending at angles to radial and tangential directions in relation to said axis; and means for supplying a substance containing a liquid fraction and a solid fraction to said inlets so that the substance moving outwardly in said first cavities under the action of the centrifugal force travels along said screen means whereby the liquid fraction passes through said screen means into said second cavities and out of said outlets from said firstcavities, each separator means hav- 7 ing a second cavity with a second outlet at said outer end, and including a screen mean closing said-second cavity and extending at angles to radial and tangential direci tions in relation to said axis; and means for supplying a substance containing a liquid fraction and a solid fraction to said inlets so that the substance moving outwardly in said first cavities under the action of the. centrifugal force travels along said screen means whereby the liquid fraction passes through said screen means into said second cavities and out of said second outlets while the solid fraction is discharged from said first outlets and through said outlet openings.

. 3. A centrifugal separator, comprising, in combination, a rotary drum having an axis and an annular peripheral Wall formed with outlet openings, and including a plurality of annular ribs surrounding said annular peripheral wall and crossing said outlet openings, said annular ribs having tapered annular edge portions in the regionzof said outlet openings; a plurality of separator means disposed in said drum in circumferentially adjacent positions abutting each other to form first cavities between each other and having adjacent inner ends forming inletsinto said first cavities and outer ends abutting said peripheral wall and forming between each other first outletsfrom said first cavities, each separator means having a second cavity with a second outlet at said outer end, and including a screen means closing said second cavity and extending at angles to radial and tangential directions in relation to said axis; and means for supplying a substance containing a liquid fraction and a solid fraction to said inlets so that the substance moving outwardly in said first cavities under the action of the centrifugal force travels along said screen means whereby the liquidfraction passes through said screen means into said second cavities and out of said second outlets while the solid fraction is discharged from said first outlets and through said outlet openings while said inner tapered annular edges of said ribs guide the solid fraction in said outlet openings between said ribs.

4. A centrifugal separator, comprising, in combination, a rotary drum having an axis and anannular peripheral wall formed with outlet openings, and a pair of walls transverse to said axis, one of said walls having a central opening; a plurality of separator means disposed in said drum in circumferentially adjacent positions abutting each other to form first cavities between each other and having adjacent inner ends. forming inlets into said first cavities and outer ends abutting said peripheral wall and forming between each other first outlets from said first cavities, each separator means having a second cavity with a second outlet at said outer end, and including a screen means closing said second cavity and extending at angles to radial and tangential directions in relation to said axis; and means for supplying a substance containing a liquid fraction and a solid fraction to said inlets and including a supply pipe projecting through said central opening of said drum into the interior of the same the action of the centrifugal force traveling along said screen means whereby the liquid fraction passes throughv said screen means into said second cavities and out of said second outlets while the solid fraction is discharged from said first outlets and through said outlet openings.

5. A centrifugal separator, comprising, in combination, a rotary drum having an axis and an annular peripheral wall formed with outlet openings; a plurality of separator means disposed in said drum in circumferentially adjacent positions abutting each other to form first cavities between each other and having adjacent inner ends forming inlets into said first cavities and outer ends abutting said peripheral Wall and forming between each other first outlets from said first cavities, said inner ends being arranged in a circle and forming a central space within said drum, each separator means having a second cavity with a second outlet at said outer end, and including a screen means closing said second cavity and extending at angles to radial and tangential directions in relation to said axis; a plurality of guide vanes of logarithmic configuration located in said central space and having closely spaced inner ends and outer ends located adjacent said inner ends of said separator means; drive means for rotating said guide vanes at a rotary speed different from the rotary speed of said drum; and pipe means projecting into said central space and located inwardly of said inner ends of said guide vanes surrounded by the same and having a slot for supplying a substance containing a liquid fraction and a solid fraction to said inlets so that the substance moving outwardly in said first cavitie under the action of the centrifugal force travels along said screen mean whereby the liquid fraction passes through said screen means into said second cavities and out of said second outlets while the solid fraction is discharged from said first outlets and through said outlet openings.

6. A centrifugal separator as set forth in claim wherein said inner ends of said guide vanes have end portions curved in a direction opposite to the logarithmic curvature of said guide vanes and extending into the proximity of adjacent guide vanes so that narrow inlet gaps are formed between the inner ends of said guide vanes.

7. A centrifugal separator, comprising, in combination, a rotary drum having an axis and an annular peripheral wall formed with outlet openings; a plurality of separator means disposed in said drum in circumferentially adjacent positions abutting each other to form first cavities between each other and having adjacent inner ends forming inlets into said first cavities and outer ends abutting said peripheral wall and forming between each other first outlets from said first cavities, each separator means having a second cavity with a second outlet at said outer end, and including a curved inwardly concave screen means closing said second cavity and extending throughout its curvature at angles to radial and tangential directions in relation to said axis; and means for supplying a substance containing a liquid fraction and a solid fraction to said inlets so that the substance moving outwardly in said first cavities under the action of the centrifugal force travels along said screen means whereby the liquid fraction passes through said screen means into said second cavities and out of said second outlets while the solid fraction is discharged from said first outlets and through said outlet openings, the angles of curvature of said screens being selected so that the component of the centrifugal force acting to transport said substance is smaller than the angle of friction of said solid fraction on said screen means.

8. A centrifugal separator, comprising, in combination, a rotary drum having an axis and an annular peripheral wall formed with outlet openings; a collector housing surrounding said rotary drum; drive means for rotating said drum about said axis; a plurality of separator means disposed in said drum in circumferentially adjacent positions abutting each other to form first cavities between each other and having adjacent inner ends forming inlets into said first cavities and outer ends abutting said peripheral wall and forming between each other first outlets from said first cavities, said first cavities registering with said outlet openings in said annular peripheral wall, each separator means having a second cavity with a second outlet at said outer end, said second outlet including a duct located in an axial plane passing through said axis and being inclined at a small angle to the same, each separator means including a screen means closing said cavity and extending at angles to radial and tangential directions in relation to said axis; and means for supplying a substance containing a liquid fraction and a solid fraction to said inlets so that the substance moving outwardly in said first cavities under the action of the centrifugal force travels along said screen means whereby the liquid fraction passes through said screen means into said second cavities and out of said second outlets while the solid fraction is discharged from said first outlets and through said outlet openings.

9. A centrifugal separator as set forth in claim 8, wherein said rotary drum includes a pair of lateral walls transverse to said axis, one of said lateral walls having a plurality of circumferentially spaced outlet means communicating, respectively, with the outer ends of said ducts; a frustoconical guide ring secured to said one lateral wall surrounding said outlet means for guiding the liquid fraction in outward and axial directions away from said outlet means; and a second collector housing surrounding said frustoconical ring and having a main outlet for the liquid fraction.

10. A centrifugal separator as set forth in claim 9, wherein the other lateral wall of said drum has a central opening 'bounded by an annular edge located inwardly of said inner ends of said separator means; wherein said means for supplying the substance includes a pipe projecting through said central opening into the interior of said drum and having a slot for discharging the substance; and guide vanes located within said drum surrounding said pipe and extending into the proximity of said inner ends and inlets of said separator means; and drive means for rotating said guide vanes at a different speed than the rotary speed of said drum.

11. A centrifugal separator as set forth in claim 10, wherein said drive means of said drum includes a hollow shaft, and said drive means of said guide vanes includes a shaft located within said hollow shaft; and comprising a drive motor, and two transmissions having different ratios and respectively connecting said drive motor with said hollow shaft and with said shaft within said hollow shaft.

12. A centrifugal separator, comprising, in combination, a rotary drum having an axis and an inner annular peripheral wall formed with outlet openings; a plurality of separator means disposed in said drum in circumferentially adjacent positions each separator means including a curved inwardly concave wall having inner and outer ends, said concave Wall being formed on one side with grooves extending between said inner and outer ends, each concave wall having on the other side thereof ribs curved in accordance with the curvature of the adjacent separator means, each separator means including a screen means extending between said inner and outer ends on said one side and closing said grooves, said ribs abutting said separator means adjacent said other side and forming with the same a first cavity, and said grooves and screen means forming a second cavity, said inner ends of said walls of said separator means forming inlets into said first cavity, and said outer ends of said walls abutting said peripheral wall and forming between each other first outlets from said first cavity communicating with said outlet openings in said annular wall, said outer ends being formed with second outlets communicating with said second cavities; said screen means being curved and inwardly concave and extending throughout the curvature thereof at angles to radial and tangential directions in relation to said axis; and means for supplying a substance containing a liquid fraction and a solid fraction to said inlets so that the substance moving outwardly in said first cavities under the action of the centrifugal force travels along said screen means whereby the liquid fraction passes through said screen means into said second cavities and out of said second outlets while the solid fractionis discharged from said first outlets and through said outlet openings.

13. A centrifugal separator as set forth in claim 12 wherein said wall of each separator has two ribs at the axial ends thereof, and wherein said ribs of adjacent separator means abut each other, said ribs having outer convex abutment edges having the same curvature as the respective surface portions of the adjacent separator means engaged thereby.

14. A centrifugal separator as set forth in claim 13 and including sealing means located in said first cavities adjacent said ribs and respectively abutting said walls of adjacent separator means to seal said cavities.

15. A centrifugal separator as set forth in claim 13 wherein said inner end of each separator wall has an undercut recess; wherein the inner end of each screen means is formed with a hollow bead located in said recess; and including a pin in said recess for holding said inner end of said screen means.

16. A centrifugal separator asset forth in claim 13 wherein said inner end of each wall'of each separator means has a tongue inwardly projecting in a direction different from the direction of said wall of each separator means and forming with the tongue of the adjacent separator means a gap constituting said inlet, the width of said gap being determined by the height of said ribs at the inner ends of said separator means.

17. A centrifugal separator as set forth in claim 13 wherein said outer end of said wall of each separator means is an abutment portion extending in axial direction along the axial extension of said annular peripheral wall of said drum, and having an abutment surface abut- :ting the inner surface of said annular peripheral wall having the same cylindrical curvature, said abutment portions having radial faces confronting each other. and forming said first outlets from said first cavities, said radial faces being located on opposite sides of said outlet openings in said annular peripheral wall, and wherein said drum includes annular ribs surrounding said annular peripheral wall and crossing said first outlets, said annular ribs having blade-like inwardly tapered edge portions in the region of said first outlets to guide the solid fraction along the sides of said annular ribs.

No references cited.

REUBEN FRIEDMAN, Primary Examiner,

J. DE CESARE, Assistant Examiner.

Non-Patent Citations
Reference
1 *None
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3926661 *Feb 1, 1974Dec 16, 1975Steprath WernerCentrifuge construction
US5720879 *Feb 8, 1996Feb 24, 1998Elgin National Industries, Inc.Horizontal centrifugal separator with angulated vanes
US5897774 *Jan 20, 1998Apr 27, 1999Elgin National Industries, Inc.Centrifugal separator with angulated vanes
US5948256 *Jan 14, 1998Sep 7, 1999Baker Hughes IncorporatedCentrifuge with cake churning
US6145669 *Jul 22, 1999Nov 14, 2000Baker Hughes IncorporatedCentrifuge with cake churning
US8511475Jul 3, 2008Aug 20, 2013Evodos B.V.Separating device and method
Classifications
U.S. Classification210/330, 210/380.3, 210/377
International ClassificationB04B7/16, B04B7/00, B04B3/00, B04B7/18
Cooperative ClassificationB04B7/16, B04B7/18, B04B3/00
European ClassificationB04B7/16, B04B3/00, B04B7/18