Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B04—CENTRIFUGAL APPARATUS OR MACHINES FOR CARRYING-OUT PHYSICAL OR CHEMICAL PROCESSES
  • B04B—CENTRIFUGES
  • B04B9/00—Drives specially designed for centrifuges; Arrangement or disposition of transmission gearing; Suspending or balancing rotary bowls
  • B04B9/06—Fluid drive
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B04—CENTRIFUGAL APPARATUS OR MACHINES FOR CARRYING-OUT PHYSICAL OR CHEMICAL PROCESSES
  • B04B—CENTRIFUGES
  • B04B5/00—Other centrifuges
  • B04B5/005—Centrifugal separators or filters for fluid circulation systems, e.g. for lubricant oil circulation systems
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B04—CENTRIFUGAL APPARATUS OR MACHINES FOR CARRYING-OUT PHYSICAL OR CHEMICAL PROCESSES
  • B04B—CENTRIFUGES
  • B04B1/00—Centrifuges with rotary bowls provided with solid jackets for separating predominantly liquid mixtures with or without solid particles
  • B04B1/04—Centrifuges with rotary bowls provided with solid jackets for separating predominantly liquid mixtures with or without solid particles with inserted separating walls
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B04—CENTRIFUGAL APPARATUS OR MACHINES FOR CARRYING-OUT PHYSICAL OR CHEMICAL PROCESSES
  • B04B—CENTRIFUGES
  • B04B7/00—Elements of centrifuges
  • B04B7/08—Rotary bowls
  • B04B7/12—Inserts, e.g. armouring plates

Definitions

• the present invention relates to centrifugal separators intended for freeing a liquid from particles suspended therein and having a larger density than the liquid. More precisely the invention concerns a rotor for a centrifugal separator of this kind, which is rotatable around its centre axis and includes a casing having two axially separated end walls and a surrounding wall situated therebetween and surrounding the centre axis; an inlet member delimiting an inlet channel centrally in the casing; a separation means mounted in the casing; and at least one outlet member situated in the area of one of the end walls, spaced from the centre axis and delimiting an outlet channel, which is directed in a way such that liquid flowing out therethrough accomplishes a reaction force on the rotor in its circumferential direction.
• Rotors of this kind formed for reaction drive by means of an overpressure of the liquid to be cleaned, are known since long. As a rule they have been used for cleaning of relative small liquid flows and have been relatively small and light.
• inserts have been suggested in the form of filters of different kinds.
• GB 1 089 355 and GB 1 595 816 show examples of such filter inserts.
• different kinds of separation inserts have been suggested which are formed such that they shorten the sedimentation distance for particles, which are to be separated within the rotor from liquid supplied 2
• GB 729 169 shows a separation insert in the form of a helical wall, which delimits a helical flow path within the rotor for the liquid to be cleaned.
• US 5,637,217 shows a separation insert having conical separation discs.
• US 2,067,273 shows a further construction of a centrifugal rotor of the initially defined kind.
• a separation means including a lot of separation discs, which are arranged within the casing between the centre axis and the surrounding wall of the casing and distributed around the centre axis, so that they form a lot of axially extending separation channels.
• Each separation disc extends both axially and in a direction from the centre axis towards the surrounding wall of the casing from a radially inner edge to a radially outer edge, forming an angle with imaginary radii extending from the centre axis to the surroun- ding wall.
• the object of the present invention is to provide a rotor of the initially defined kind, intended for reaction drive and provided with a particular separation means in the separation space of the rotor, which rotor can be given a better separation efficiency than previously known rotors of this kind.
• a rotor of the initially defined kind is provided with a separation means of the kind included in a centrifugal rotor according to US 2,067,273 and, further, is provided with an inlet member delimiting an inlet channel centrally in the casing, which inlet channel communicates with the separation channels through a distribution chamber situated between a first one of the casing end walls and said separation means, said separation channels extending 3
• a rotor of this kind is further characterized in
• a partition is arranged between the separation discs and said other end wall of the casing in a way such that it delimits on its one side a collection chamber, in which the separation channels open, and on its other side delimits an outlet chamber,
• the afore-mentioned outlet channel communicates with the outlet chamber and extends to the outside of the rotor, where it opens in a liquid free space at a radial level outside said level, at which the collection chamber and the outlet chamber communicate with each other.
• a rotor according to the invention it is possible to accomplish a relatively small through-flow resistance for the liquid to be cleaned, when this liquid passes through the rotor separation means, i.e. through said separation channels delimited between the separation discs.
• a separation means of the kind suggested according to the invention and, per se, previously known in other kinds of centrifugal separators creates a surprisingly small through-flow resistance for the liquid to be cleaned, particularly if the liquid has a low viscosity.
• the centrifugal rotor according to the invention may be given a better separation efficiency. This depends on the circumstance that the known centrifugal rotor has a less effective driving means than the centrifugal rotor according to the invention.
• the outlet nozzles for the reaction drive of the known centrifugal rotor are situated at a very small radius. Furthermore, the outlet channels of these nozzles open into liquid which is subjected to a certain overpressure.
• FIG. 1 shows a section through the centrifugal rotor, taken along a line l-l in figure 2, and figure 2 shows the centrifugal rotor in figure 1 seen from above, only half of a casing surrounding the centrifugal rotor being shown.
• the figures 3-5 show a second embodiment of the centrifugal rotor according to the invention.
• figure 3 shows a section similar to that of figure 1.
• Figure 4 is a mixture of a view and a section along the line A-A in figure 3 and shows the radial extension of certain wings in the upper part of the centrifugal rotor.
• Figure 5 illustrates parts of the centrifugal rotor, part of its surrounding casing being removed.
• the rotor in figures 1 and 2 includes a circular base plate 1 , which has a central opening 2 and centrally supports a tubular column 3.
• the interior of the column 3 forms a channel 4, which communicates with the central opening 2 of the base plate.
• An annular cap 5 is placed around the column 3 and is kept fastened thereto and to the base plate 1 by means of a nut 6.
• base plate 1 form a casing around a separation chamber 7 in the rotor.
• the base plate 1 forms a first end wall
• the cap 5 forms a second end wall 8 and a surrounding wall 9.
• the surrounding wall 9 extends between the end walls 1 and 8 concentrically around the tubular column 3.
• the rotor is rotatable around a centre axis 10 and for this purpose the central column 3 supports bearing members 3a and 3b at its respective ends.
• the rotor has a separation means comprising a large number of separation discs 11 evenly distributed around the rotor centre axis 10.
• Each one of the separation discs extends both arcuately in a direction from the centre axis 10 towards the surroun- ding wall 9, as can be seen from figure 2, and axially between flow distributing and liquid entraining upper radial wings 12 and lower arcuately extending wings 13, as can be seen from figure 1.
• the separation discs 11 form between themselves thin separation channels, which have the same extension as the separation discs. In figure 2 part of the separa- tion discs have been left out so that some of the lower arcuately extending wings 13 can be seen.
• the separation discs 11 are supported, like the wings 12 and 13, by a central supporter comprising a sleeve 14, which surrounds and is guided by the central column 3.
• the sleeve 14 is formed in one piece with a lower annular supporting member 15, which extends by an axially upwardly directed annular fastening flange into recesses intended therefor in the lower edge portions of the separation discs 11.
• Correspondingly formed recesses in the upper edge portions of the separation discs form 7
• annular upwardly open groove for an axially downwardly directed annular fastening flange of an upper annular supporting member 16.
• the supporting members 15 and 16 can be axially separated from each other and from the separation discs 11 by the sleeve 4 being divided at 17 (fig. 1 ).
• the radially outer parts of the separation discs 11 are kept in place relative to each other by means of three rings 18, which at different axial levels surround all of the separation discs. For reasons evident from the following the uppermost of these rings 18 fills the whole interspace between the separation discs 11 and the surrounding wall 9 of the casing.
• the separation discs 11 are kept at a certain distance from each other by means of spacing members 19 formed in one piece with the separation discs and distributed across their surfaces in some suitable manner.
• annular partition is adapted to extend from the surrounding wall 9 of the casing radially inwardly to the area of the radially innermost parts of the separation discs 11.
• the partition has a central plane portion 20 situated axially opposite to the separation discs 11 ; a short cylindrical intermediate portion 21 surrounding the wings 13; and radially outermost a further plane portion 22, which fills the interspace between the surrounding wall 9 of the casing and the radially outer lowermost parts of the separa- tion discs 11.
• a liquid to be cleaned in the rotor is to enter by an overpressure into the channel 4 through the opening 2 in the base plate 1.
• the liquid may enter the channel 4 from the opposite direction. From the channel 4 liquid is to be conducted through openings 23 in the column 3 8
• a distribution chamber 24 which is formed in the upper part of the casing 5 and in which the upper radial wings 12 are situated.
• the liquid shall flow axially through the separation channels formed between the separation discs 11.
• particles suspended in the liquid and being heavier than the liquid are to be separated, and liquid is to flow furtheron downwards to a collecting chamber 25, in which the arcuately extending lower wings 13 are situated.
• the wings 13 have an arcuate extension opposite to that of the separation discs 11.
• the wings 13 may give axial support to a larger number of separation discs than if they extended only radially and, still, function as members for rotational entrainment of liquid situated in the collecting chamber 25.
• the uppermost ring 18 prevents an axial liquid flow radially outside the separation discs 11.
• the base plate 1 is provided with two depressions, which form two outlet chambers 26 below the partition portion 20. These outlet chambers 26 communicate with the afore-mentioned collecting chamber 25 at the radially inner edge of the partition portion 20.
• the base plate 1 is provided with a nozzle having an outlet channel 27.
• the outlet channel 27 opens in a liquid free space, which is at atmospheric pressure, outside the rotor at a level radially outside the inner edge of the partition portion 20.
• the separation discs 11 as well as the members 14-16 keeping them in place in the rotor may, preferably, be made of plastics. If desired, the separation discs may be formed in a way such that they extend through substantially the whole of the separation chamber of the rotor.
• An advantage with separation discs of the kind described here, in compari- son with conical separation discs, is that all of the discs may be formed identically alike and, in spite of this, be given a form such that they extend in all desired parts of the separation chamber.
• a package of such separation discs thus, is not bound to a certain geometrical shape in the same way as is a stack of identically formed conical separation discs, but may be adapted to a desired shape of the rotor. Therefore, an available space within the rotor may be utilized to its maximum for the centrifugal separation in question.
• An insert of this kind could comprise the above described partition 20-22 and a cylindrical container formed in one piece therewith and adapted to form a removable liner within the described cap 5.
• a liner of this kind could extend from the partition 20-22 up to the uppermost ring 18 surrounding the separation discs.
• FIGS 3-5 show a somewhat modified centrifugal rotor according to the invention.
• the same reference numerals have been used in the figures 3-5 as in figures 1 and 2 for corresponding details.
• the separation discs 11 are mounted in a supporter comprising a lower supporting member 15a and an upper supporting member 16a.
• the supporting members 15a and 16a are removably connected with each other by means of a snap lock device 17a and are guided by the central column 3.
• the snap lock device 17a is placed radially inside the separation discs 11 about half-way between their axial ends, whereby it is relatively difficult to reach and, thus, cannot be opened unintentionally. Thereby, the separation discs cannot be freed unintentionally from the supporting members 15 and 16a.
• the lower supporting member 15a is formed in one piece with the partition 20 and with the wings 13 in the collecting chamber 25.
• the upper supporting member 16a is formed in one piece with the wings 12 in the distribution chamber 24.
• the wings 12 are of two different kinds. Two wings 12a, which are situated diametrically on opposite sides of the column 3, extend substantially all the way into the column 3 in the plane wherein the inlet openings 23 of the column 3 are situated. The other wings 12b do not extend, in this plane, into the column 3 but leaves between themselves and the column 3 free spaces 28.
• the column 3 has two inlet openings 23 for liquid to be treated in the rotor. Each one of these openings opens in an area situated imme- diately in front of one of the wings 12a extending all the way into the column 3, seen in the rotational direction of the rotor. This rotational direction is shown by an arrow w in figure 4.
• liquid entering the rotor through an opening 23 will be entrained in the rotor rotation by the adjacent wing 12a and, thus, be prevented from sliding relative to the rotor in a direction opposite to its rotational direction.
• the wings is an advantageous alternative to having a large number of relatively small inlet openings in the column 3, e.g. one inlet opening in each interspace between adjacent wings, for accomplishment of an even distribution of liquid in the rotor separation chamber.
• the above described arrangement may be used as soon as the number of wings 12 exceeds the number of inlet openings 23.
• the uppermost ring 18a which surrounds the separation discs, does not extend all the way out to the casing 5 but leaves a small space 29 between itself and the casing.
• This space is dimensioned such that it allows passage of solids, which are separated from the incoming liquid already in the distribution chamber 24 and, thus, deposit on the inside of the casing 5 already in the area of the ring 18a. After a short time of rotor operation a layer of particles having deposited on the inside of the casing will at least partly fill the space 29.
• the casing 5 is also slightly conical, so that its diameter increases in the axial direction away from the distribution chamber 24, which contributes to avoiding complete clogging of the space 29.

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• Centrifugal Separators (AREA)
• Fertilizing (AREA)

Applications Claiming Priority (3)

Publications (2)

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ID=20410858

Family Applications (1)

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• 1998
  • 1998-04-02 SE SE9801183A patent/SE9801183D0/xx unknown
• 1999
  • 1999-03-30 CN CN99806993A patent/CN1104959C/zh not_active Expired - Fee Related
  • 1999-03-30 BR BR9909347-2A patent/BR9909347A/pt not_active IP Right Cessation
  • 1999-03-30 AU AU36341/99A patent/AU3634199A/en not_active Abandoned
  • 1999-03-30 AT AT99918411T patent/ATE439913T1/de not_active IP Right Cessation
  • 1999-03-30 KR KR1020007010981A patent/KR100577663B1/ko not_active IP Right Cessation
  • 1999-03-30 WO PCT/SE1999/000515 patent/WO1999051353A1/en active IP Right Grant
  • 1999-03-30 DE DE69941290T patent/DE69941290D1/de not_active Expired - Lifetime
  • 1999-03-30 EP EP99918411A patent/EP1068016B1/de not_active Expired - Lifetime
  • 1999-03-30 JP JP2000542112A patent/JP3431598B2/ja not_active Expired - Fee Related
• 2000
  • 2000-09-29 NO NO20004894A patent/NO20004894L/no not_active Application Discontinuation

Non-Patent Citations (1)

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