EP0076476A2 - Décanteur centrifuge - Google Patents

Décanteur centrifuge Download PDF

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Publication number
EP0076476A2
EP0076476A2 EP82109062A EP82109062A EP0076476A2 EP 0076476 A2 EP0076476 A2 EP 0076476A2 EP 82109062 A EP82109062 A EP 82109062A EP 82109062 A EP82109062 A EP 82109062A EP 0076476 A2 EP0076476 A2 EP 0076476A2
Authority
EP
European Patent Office
Prior art keywords
drum
decanter centrifuge
centrifuge according
screw conveyor
screw
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
EP82109062A
Other languages
German (de)
English (en)
Other versions
EP0076476A3 (fr
Inventor
Werner Dr. Stahl
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from DE3139345A external-priority patent/DE3139345C2/de
Priority claimed from DE3142805A external-priority patent/DE3142805C2/de
Application filed by Individual filed Critical Individual
Publication of EP0076476A2 publication Critical patent/EP0076476A2/fr
Publication of EP0076476A3 publication Critical patent/EP0076476A3/fr
Ceased legal-status Critical Current

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    • 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
    • B04B1/20—Centrifuges with rotary bowls provided with solid jackets for separating predominantly liquid mixtures with or without solid particles discharging solid particles from the bowl by a conveying screw coaxial with the bowl axis and rotating relatively to the bowl
    • 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
    • B04B1/20—Centrifuges with rotary bowls provided with solid jackets for separating predominantly liquid mixtures with or without solid particles discharging solid particles from the bowl by a conveying screw coaxial with the bowl axis and rotating relatively to the bowl
    • B04B2001/2041—Centrifuges with rotary bowls provided with solid jackets for separating predominantly liquid mixtures with or without solid particles discharging solid particles from the bowl by a conveying screw coaxial with the bowl axis and rotating relatively to the bowl with baffles, plates, vanes or discs attached to the conveying screw

Definitions

  • the principle of a decanter can basically be regarded as a sedimentation basin, which is rolled up into a self-contained casing and whose effectiveness is greater to the extent that the centrifugal force exceeds the acceleration due to gravity.
  • the calculation method using the Stokes sink rate is based on this idea.
  • the solid cake forms there under sedimentation and already has a solid consistency in the cylindrical part of the drum.
  • the solid cake must therefore be broken open as it passes the kink between the cylindrical and the conical part of the drum, and it must be brought into a new shape adapted to the cone.
  • a low backflow velocity is particularly important for a calm flow. For a given liquid flow it therefore appears reasonable to choose screw channels as wide as possible, which would theoretically be achievable by increasing the screw pitch. This endeavor, however, contradicts experience and the well-founded fear that the solids transport can no longer be carried out properly.
  • the immersion screw is based on the idea of allowing the liquid or at least part of the liquid to flow within a heavily perforated screw base body on a short-circuit path to the overflow. Flow and sedimentation disturbances in the screw chamber should thereby be limited and have no influence on the calm zone in the screw hollow body.
  • the main screw body was made large, narrow screw blades were used and the centrate was allowed to flow through the perforation in the screw body itself to the overflow edge.
  • the disadvantage that when the rotor was running full during operation, sedimented solid fell into the inside of the screw body and tended to stick on one side. When starting again, the decanter was unbalanced and the rotor also had to be dismantled to clean it.
  • the invention has for its object to provide a decanter centrifuge of the type mentioned above, with which an exceptionally good clarifying effect can be achieved with an otherwise good dehumidification and promotion of the solids by influencing the flow in the region of the inner surface of the drum.
  • the invention basically provides for the flow velocity in the vicinity of the base layer or the drum to be reduced considerably, so that the sudden increase in the solids content in the centrate, which was previously feared by experts in the field, can be effectively avoided and a considerably improved clarifying effect can be brought about.
  • the internals are arranged in the region of the middle of the liquid level.
  • the advantage is achieved that, on the one hand, the flow velocity between the internals and the drum is greatly reduced, while, on the other hand, there is still enough space for the solid cake to be transported further beneath the internals.
  • the distance between the internals and the drum is constant over the length of the drum or that the distance between the internals and the drum decreases over the length of the drum. In this way, the expected distribution of the amount of solid over the length of the drum can be taken into account.
  • the internals consist of roof profile elements, flat material elements, round bolts, perforated plates and / or expanded metal arranged essentially parallel to one another.
  • the shape and distance between the individual built-in elements are dimensioned such that sedimenting particles can slip on the relatively steep surfaces of the internals and enter the protected area below the internals and are constantly deposited there. This significantly improves the clarifying effect.
  • the elements are arranged parallel to the drum axis or that the elements are arranged perpendicular to the surface of the screw blades. With such an arrangement. the result is a structurally relatively simple arrangement.
  • the permanent retention of solid particles can also be brought about by the step of the diameter of the screw conveyor springing back along the drum at predetermined intervals. It can preferably also be provided that the diameter of the inner surface of the drum springs back in steps and that a gap which is substantially constant over the length of the drum is formed between the screw conveyor and the drum.
  • solid particles which have already reached the base layer, but are still carried along the drum due to considerable drag forces, are brought before the individual stages into areas in which the flow is largely calm, so that the Can finally sediment solid particles in these areas, since they practically cannot get over the preceding stage.
  • the adhesive layer has magnetic properties.
  • a base layer made of a suitable foreign material such as a heavy ore or a tar-like material or generally in the form of a non-Newtonian liquid can also be produced within the drum before a decanter centrifuge is started up.
  • a base layer can be formed within the drum, which, due to its geometric configuration and / or its adhesive properties, significantly promotes the carry-over process.
  • the invention includes the risk, despite the many years of experience and fears of the professional world, of using an increase in the screw conveyor that goes far beyond the values which were previously customary and considered useful.
  • the extraordinarily great advantage can be achieved that a surprisingly good clarification of the liquid is brought about.
  • a disturbance of the flow of the liquid flowing away in the screw blades can be avoided.
  • the harmful backflow rate is kept particularly low in the arrangement according to the invention.
  • the pitch of the screw conveyor in the intensive clarifying area is approximately fifteen to sixty degrees.
  • the arrangement is preferably such that between the area of the screw conveyor with normal conventional pitch and the intensive Clarification area, a transition area is formed in which the slope of the screw conveyor increases gradually and steadily.
  • transition region it has proven to be particularly advantageous for the transition region to extend over approximately 360 degrees.
  • a further advantageous embodiment of the subject matter of the invention is characterized in that the transition region is arranged in the border area between the conical and the cylindrical part of the drum.
  • a particularly effective development of the subject matter of the invention further provides that in the intensive clarification area the pitch of the screw conveyor increases progressively away from the conical part, as a result of which a diffuser part is formed. It can preferably be provided that flow guide plates are arranged in the diffuser part between the screw blades.
  • the advantage of the guide plates is that the flow in the divergent flow channel is brought to bear on the walls of the flow channel.
  • the invention makes use of the knowledge that it is possible to couple the apparently contradicting requirements, that on the one hand the solid must be transported and discharged reliably and quickly, while on the other hand the greatest possible calming of the flow is desirable.
  • the low pitch of the screw conveyor in the conical part of the drum is maintained and preferably also extended over a certain part of the cylindrical region of the drum. Then, according to the invention, however, after a preferably gradual and steady transition, an exceptionally large gradient of the screw can be achieved, and this results in a substantially reduced flow rate and thus surprisingly undisturbed, effective and good clarification.
  • the upper limit of the pitch of the screw conveyor which is still possible within the scope of the invention depends to a large extent on the roughness of the screw blades. Furthermore, there is of course a dependency on the properties of the product and also on the state of wear of the screw blades. In general, it can be stated that the upper limit of the pitch of the screw conveyor which is still possible within the scope of the invention largely depends on the surface condition of the screw blades.
  • a screw conveyor is arranged within a drum 10, of which the screw base body 13 is illustrated in a partial section. Both the drum and the screw conveyor rotate about a common axis, but at different speeds. According to the illustration in FIG. 1, a liquid 15 is held along the inner surface of the drum 10 up to a liquid level 16 in a corresponding layer along the drum by the centrifugal force. The solid particles, which are specifically heavier than the liquid, have a tendency to settle on the inner surface of the drum 10. Since a liquid flow channel is formed between adjacent screw blades, as shown, for example, in FIG.
  • the internals are arranged somewhat below the center of the liquid level 16 and are at a distance from the drum 10 which is dimensioned such that the solid cake to be transported can be conveyed under the internals.
  • the shape and distance between the built-in elements are dimensioned such that sedimenting particles slide on relatively steep surfaces of the built-in parts and can enter the protected area below the built-in parts.
  • FIG. 2 shows within a drum 20 a conveyor screw designated in its entirety with 22, which has a screw blade 24 on a screw base body 23, which is provided with recesses 25 in the area of the blade tip.
  • the crenellated recesses 25 in FIG. 2A produce a complementary configuration in the base layer 21a.
  • 2B to 2D show alternative configurations of base layers 21b, 21c and 21d, which result from corresponding recesses in the screw conveyor.
  • 20 grooves, grooves or the like can be formed in the base layer 21 within the drum, which practically serve as "pitfalls" for solid particles.
  • the distance between the blade tip of the screw and the inner wall of the drum is deliberately proportionate, large in order to be able to form a relatively thick base layer, in which, according to the invention, pitfalls for solid particles of more suitable Surfaces- Structure and above all with sufficient depth can be generated.
  • FIG. 3 illustrates purely schematically within a drum 30 a screw conveyor 32, the diameter of which tapers step-like along the drum.
  • a screw conveyor 32a is arranged inside a drum 30a, which has a screw blade 34 on a screw base 33 which tapers in steps along the drum 30a.
  • the diameter of the drum 30a also tapers in accordance with the diameter of the screw conveyor, so that a base layer 31a is formed which has a substantially constant thickness over the longitudinal extent of the drum 30a.
  • the arrangement according to FIG. 3B differs from the corresponding arrangement according to FIG. 3A essentially in that a drum 30b is present, the inside diameter of which remains essentially constant over the longitudinal extent of the drum 30b. Since the diameter of a worm blade 34b attached to a screw conveyor 32b progressively tapers, a base layer 31b is formed between the screw conveyor 33 and the drum 30b, which layer progressively thickens along the drum 30b in the direction of flow of the center. In other words, the thickness of the base layer 31b increases stepwise or abruptly in the flow direction of the liquid.
  • the decanting device designated in its entirety by 110, is not shown completely in FIG. 4 of the drawing; rather, only the components required for understanding the invention are illustrated.
  • a screw conveyor 112 is arranged within a drum 111, which has a cylindrical part 111a and a conical part 111b.
  • the drum 111 as well as the screw conveyor 112 are drawn purely schematically in a half section.
  • the blades of the screw conveyor are drawn at relatively large distances with respect to a transition area 114 and in particular with respect to the conical part 111b of the drum 111. According to the illustration, the blades of the screw conveyor are not arranged equidistantly within the intensive clarification area 113, the distances rather increase towards the right part of the illustration.
  • the pitch of the screw conveyor is gradually and steadily increased, so that in the entire intensive clarifying area 113, which extends as shown in the drawing over the largest part of the cylindrical drum area, the screw conveyor 112 has a much larger pitch than in has conical part 111 of the drum.
  • the slope increases continuously in a diffuser part 115, so that a diverging flow channel is formed in this diffuser part 115.
  • the task zone is illustrated purely schematically in the drawing to complete the illustration at 117.
  • the transition region 114 could also be moved further from the kink between the conical and the cylindrical part of the drum 111 into the cylindrical part of the drum.
  • the device-related design of the transition area and its extension could also be modified without departing from the scope of the invention.
  • the extent of the transition area can be more or less than 360 degrees.
  • the invention basically encompasses all arrangements in which within the cylindrical part of the drum the screw conveyor has a considerably larger gradient in an intensive clarification area than in conventional devices in which the gradient is below ten degrees.

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  • Centrifugal Separators (AREA)
EP82109062A 1981-10-02 1982-09-30 Décanteur centrifuge Ceased EP0076476A3 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
DE3139345 1981-10-02
DE3139345A DE3139345C2 (de) 1981-10-02 1981-10-02 Vollmantel-Schneckenzentrifuge
DE3142805 1981-10-28
DE3142805A DE3142805C2 (de) 1981-10-28 1981-10-28 Vollmantel-Schneckenzentrifuge

Publications (2)

Publication Number Publication Date
EP0076476A2 true EP0076476A2 (fr) 1983-04-13
EP0076476A3 EP0076476A3 (fr) 1984-11-28

Family

ID=25796518

Family Applications (1)

Application Number Title Priority Date Filing Date
EP82109062A Ceased EP0076476A3 (fr) 1981-10-02 1982-09-30 Décanteur centrifuge

Country Status (1)

Country Link
EP (1) EP0076476A3 (fr)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2546419A1 (fr) * 1983-05-24 1984-11-30 Kloeckner Humboldt Wedag Appareillage pour deshydrater de la boue dans la zone de centrifugation d'une centrifugeuse a enveloppe pleine
DE9106885U1 (de) * 1991-06-05 1991-08-14 Lindner, Jürgen H. E., Dipl.-Chem., 4220 Dinslaken Zentrifuge zum Reinigen eines Fluid von mitgeführten Partikeln
WO1992010299A1 (fr) * 1990-12-14 1992-06-25 Westfalia Separator Aktiengesellschaft Centrifugeuse helicoidale a bol plein pour la decantation ou la separation de melanges de substances liquides et solides
EP0535658A1 (fr) * 1991-09-30 1993-04-07 LINDE-KCA-Dresden GmbH Réacteur pour le traitement des matériaux solides et liquides à contre-courant
EP0544263A1 (fr) * 1991-11-26 1993-06-02 Flottweg GmbH Centrifugeur-convoyeur à vis à paroi pleine comportant une paroi intérieure structurée
WO1993022062A1 (fr) * 1992-04-29 1993-11-11 Noxon Ab Centrifugeuse de decantation
DE19504688A1 (de) * 1995-02-13 1996-08-14 Buehler Ag Kombinierte Nassvermahlung und Nassklassierung
DE19711155A1 (de) * 1997-03-18 1998-09-24 Baumann Schilp Lucia Schichtarmierung für eine Zentrifuge mit Vollmantelteil
WO2022096734A1 (fr) * 2020-11-09 2022-05-12 Flottweg Se Vis sans fin de centrifugeuse et centrifugeuse à vis à bol plein
CN114684549A (zh) * 2022-04-19 2022-07-01 江苏大学 一种基于仿生非光滑表面和折边结构的螺旋叶片及螺旋输送器

Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE93040C (fr) *
DE2104848B (de) * Flottweg Werk Dr Georg Brück mayer, 8313 Vilsbiburg Vollmantel Schneckenzentrifuge
US1383313A (en) * 1920-06-24 1921-07-05 Clarence P Landreth Centrifugal apparatus
US2743864A (en) * 1954-03-05 1956-05-01 Bird Machine Co Centrifuge with inclined conveyor blade and vanes for rapid collection of fine particles from suspensions
FR1152315A (fr) * 1956-06-12 1958-02-14 Robatel Et Mulatier Atel Perfectionnements aux décanteuses centrifuges continues à vis d'archimède
US3096282A (en) * 1957-12-30 1963-07-02 Sharples Corp Improvement in centrifuges
DE1194779B (de) * 1963-08-14 1965-06-10 Krauss Maffei Ag Schneckenzentrifuge mit einer zum Ablaufende fuer die Gutfluessigkeit erweiterten Vollmantelschleudertrommel
FR85210E (fr) * 1964-02-07 1965-07-02 Const Guinard Décanteuse
US3343786A (en) * 1964-02-21 1967-09-26 Pennsalt Chemicals Corp Centrifuge having plural conveying means for solids
DE1432822A1 (de) * 1963-09-28 1969-05-29 Kloeckner Humboldt Deutz Ag Vollmantelzentrifuge zur kontinuierlichen Trennung von Feststoff-Fluessigkeits-Gemischen
DE2057555A1 (de) * 1970-11-23 1972-06-22 Werner Busch Schneckenzentrifuge

Patent Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE93040C (fr) *
DE2104848B (de) * Flottweg Werk Dr Georg Brück mayer, 8313 Vilsbiburg Vollmantel Schneckenzentrifuge
US1383313A (en) * 1920-06-24 1921-07-05 Clarence P Landreth Centrifugal apparatus
US2743864A (en) * 1954-03-05 1956-05-01 Bird Machine Co Centrifuge with inclined conveyor blade and vanes for rapid collection of fine particles from suspensions
FR1152315A (fr) * 1956-06-12 1958-02-14 Robatel Et Mulatier Atel Perfectionnements aux décanteuses centrifuges continues à vis d'archimède
US3096282A (en) * 1957-12-30 1963-07-02 Sharples Corp Improvement in centrifuges
DE1194779B (de) * 1963-08-14 1965-06-10 Krauss Maffei Ag Schneckenzentrifuge mit einer zum Ablaufende fuer die Gutfluessigkeit erweiterten Vollmantelschleudertrommel
DE1432822A1 (de) * 1963-09-28 1969-05-29 Kloeckner Humboldt Deutz Ag Vollmantelzentrifuge zur kontinuierlichen Trennung von Feststoff-Fluessigkeits-Gemischen
FR85210E (fr) * 1964-02-07 1965-07-02 Const Guinard Décanteuse
US3343786A (en) * 1964-02-21 1967-09-26 Pennsalt Chemicals Corp Centrifuge having plural conveying means for solids
DE2057555A1 (de) * 1970-11-23 1972-06-22 Werner Busch Schneckenzentrifuge

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2546419A1 (fr) * 1983-05-24 1984-11-30 Kloeckner Humboldt Wedag Appareillage pour deshydrater de la boue dans la zone de centrifugation d'une centrifugeuse a enveloppe pleine
WO1992010299A1 (fr) * 1990-12-14 1992-06-25 Westfalia Separator Aktiengesellschaft Centrifugeuse helicoidale a bol plein pour la decantation ou la separation de melanges de substances liquides et solides
DE9106885U1 (de) * 1991-06-05 1991-08-14 Lindner, Jürgen H. E., Dipl.-Chem., 4220 Dinslaken Zentrifuge zum Reinigen eines Fluid von mitgeführten Partikeln
EP0535658A1 (fr) * 1991-09-30 1993-04-07 LINDE-KCA-Dresden GmbH Réacteur pour le traitement des matériaux solides et liquides à contre-courant
US5372260A (en) * 1991-11-26 1994-12-13 Flottweg Gmbh Scroll-conveyor centrifuge with textured interior bowl surface
EP0544263A1 (fr) * 1991-11-26 1993-06-02 Flottweg GmbH Centrifugeur-convoyeur à vis à paroi pleine comportant une paroi intérieure structurée
WO1993022062A1 (fr) * 1992-04-29 1993-11-11 Noxon Ab Centrifugeuse de decantation
DE19504688A1 (de) * 1995-02-13 1996-08-14 Buehler Ag Kombinierte Nassvermahlung und Nassklassierung
DE19504688B4 (de) * 1995-02-13 2007-09-06 Bühler AG Kombinierte Nassvermahlung und Nassklassierung
DE19711155A1 (de) * 1997-03-18 1998-09-24 Baumann Schilp Lucia Schichtarmierung für eine Zentrifuge mit Vollmantelteil
WO2022096734A1 (fr) * 2020-11-09 2022-05-12 Flottweg Se Vis sans fin de centrifugeuse et centrifugeuse à vis à bol plein
CN114684549A (zh) * 2022-04-19 2022-07-01 江苏大学 一种基于仿生非光滑表面和折边结构的螺旋叶片及螺旋输送器
CN114684549B (zh) * 2022-04-19 2024-05-14 江苏大学 一种基于仿生非光滑表面和折边结构的螺旋叶片及螺旋输送器

Also Published As

Publication number Publication date
EP0076476A3 (fr) 1984-11-28

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