Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
  • B03B—SEPARATING SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS
  • B03B5/00—Washing granular, powdered or lumpy materials; Wet separating
  • B03B5/28—Washing granular, powdered or lumpy materials; Wet separating by sink-float separation
  • B03B5/30—Washing granular, powdered or lumpy materials; Wet separating by sink-float separation using heavy liquids or suspensions
  • B03B5/32—Washing granular, powdered or lumpy materials; Wet separating by sink-float separation using heavy liquids or suspensions using centrifugal force
  • B03B5/34—Applications of hydrocyclones
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
  • B03D—FLOTATION; DIFFERENTIAL SEDIMENTATION
  • B03D1/00—Flotation
  • B03D1/14—Flotation machines
  • B03D1/1418—Flotation machines using centrifugal forces
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
  • B03D—FLOTATION; DIFFERENTIAL SEDIMENTATION
  • B03D1/00—Flotation
  • B03D1/14—Flotation machines
  • B03D1/1431—Dissolved air flotation machines
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
  • B03D—FLOTATION; DIFFERENTIAL SEDIMENTATION
  • B03D1/00—Flotation
  • B03D1/14—Flotation machines
  • B03D1/1443—Feed or discharge mechanisms for flotation tanks
  • B03D1/1456—Feed mechanisms for the slurry
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
  • B03D—FLOTATION; DIFFERENTIAL SEDIMENTATION
  • B03D1/00—Flotation
  • B03D1/14—Flotation machines
  • B03D1/1443—Feed or discharge mechanisms for flotation tanks
  • B03D1/1462—Discharge mechanisms for the froth
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
  • B03D—FLOTATION; DIFFERENTIAL SEDIMENTATION
  • B03D1/00—Flotation
  • B03D1/14—Flotation machines
  • B03D1/24—Pneumatic
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B04—CENTRIFUGAL APPARATUS OR MACHINES FOR CARRYING-OUT PHYSICAL OR CHEMICAL PROCESSES
  • B04C—APPARATUS USING FREE VORTEX FLOW, e.g. CYCLONES
  • B04C3/00—Apparatus in which the axial direction of the vortex flow following a screw-thread type line remains unchanged ; Devices in which one of the two discharge ducts returns centrally through the vortex chamber, a reverse-flow vortex being prevented by bulkheads in the central discharge duct
  • B04C3/06—Construction of inlets or outlets to the vortex chamber
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B04—CENTRIFUGAL APPARATUS OR MACHINES FOR CARRYING-OUT PHYSICAL OR CHEMICAL PROCESSES
  • B04C—APPARATUS USING FREE VORTEX FLOW, e.g. CYCLONES
  • B04C5/00—Apparatus in which the axial direction of the vortex is reversed
  • B04C5/02—Construction of inlets by which the vortex flow is generated, e.g. tangential admission, the fluid flow being forced to follow a downward path by spirally wound bulkheads, or with slightly downwardly-directed tangential admission
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B04—CENTRIFUGAL APPARATUS OR MACHINES FOR CARRYING-OUT PHYSICAL OR CHEMICAL PROCESSES
  • B04C—APPARATUS USING FREE VORTEX FLOW, e.g. CYCLONES
  • B04C9/00—Combinations with other devices, e.g. fans, expansion chambers, diffusors, water locks
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B04—CENTRIFUGAL APPARATUS OR MACHINES FOR CARRYING-OUT PHYSICAL OR CHEMICAL PROCESSES
  • B04C—APPARATUS USING FREE VORTEX FLOW, e.g. CYCLONES
  • B04C9/00—Combinations with other devices, e.g. fans, expansion chambers, diffusors, water locks
  • B04C2009/007—Combinations with other devices, e.g. fans, expansion chambers, diffusors, water locks with internal rotors, e.g. impeller, ventilator, fan, blower, pump

Definitions

• the invention relates to a method and a device for separating the heavier from the lighter portions of aqueous turbidity by means of centrifugal force.
• the invention relates in particular to the cleaning of liquid turbidity with a proportion of solid particles below a certain dimension, i.e. for the subsequent cleaning of turbidity which has already been subjected to a preliminary cleaning to remove coarser particles through sieves or the like.
• a pre-cleaned slurry is introduced into a separation chamber at high speed in such a way that an intensely rotating laminar flow field is formed therein, so that the heavier portions of the slurry are pressed onto an outer diameter path by centrifugal force while the Lighter portions of the slurry preferably accumulate near the central longitudinal axis of the separation chamber.
• a known centrifugal separator US-A-2 996 187
• the pressure drop required for the flow of the sludge between the inlet and outlet of the separation chamber is applied by a suction transport rotor device, which is on the downstream side the outlet of the deposition chamber is provided.
• the pressure drop between the inlet and outlet is therefore determined by the suction force of the suction transport rotor device and this in turn is determined by the liquid column on the suction side, so that a pressure drop of less than 1 bar can be created by means of the suction transport rotor device.
• the known centrifugal separator can therefore only be used for suspensions in which a sufficient separation effect is obtained even at relatively low speeds of rotation of the slurry. In order to treat less easily separable parts from aqueous turbidities, higher rotation speeds are required in the separation chamber in order to generate correspondingly high centrifugal forces.
• a particular problem is the effective separation of floatable particulate matter from aqueous turbidities by means of centrifugal forces.
• US-A-4 397 741 for flotation separation it is proposed to additionally introduce a gas into the slurry circulating in a separation chamber in order to generate gas bubbles which are expected to be affected by interface effects attached heavier portions of the cloudy matter.
• the gas bubbles virtually form buoyancy bodies, so that the heavier portions not only accumulate preferentially near the central longitudinal axis of the deposition chamber, but can also be drawn off against the effect of gravity.
• the invention has for its object to provide a method and an apparatus of the type mentioned above, which creates the necessary high rotational speeds in order to be able to treat all types of turbidity, including those with floatable components, with high effectiveness.
• the improvements in the separation efficiency achieved by the provision of the transport rotor / stator devices arranged on the inlet side can be further increased if, according to a development of the invention, additional turning energy is introduced into the slurry located in the separation chamber.
• additional turning energy is introduced into the slurry located in the separation chamber.
• This can be done by arranging a cyclone rotor device in the deposition chamber, which can be driven by the same axis of rotation as the transport rotor device.
• the cyclone rotor device permits increased turbulence-free rotation speeds which are independent of the type of introduction of the slurry into the separation chamber, the counterpressure exerted by the cyclone rotor device being overcome by the pressure which the inlet-side transport rotor device exerts on the slurry.
• the measures described make the invention particularly suitable for the flotation separation of otherwise difficult to separate by means of centrifugal force Slurries, eg suitable for removing printing ink residues from slurried waste paper materials.
• a further development of the invention in this regard provides for the separation of the slurry to be carried out in the presence of gas bubbles, preferably in the presence of micro gas bubbles.
• a liquid permeated with micro gas bubbles can be introduced into the separation chamber for mixing with the slurry, or the slurry itself is gassed and introduced into the separation chamber in the gassed state.
• Foam destruction device with rotatably driven rotor blades can be provided in order to use centrifugal action to separate the foreign substances adhering to the gas bubbles in a foamy gas bubble-foreign substance mixture discharged from the separation chamber and to separate them outside.
• a centrifugal separating device is distinguished by a comparatively uncomplicated structure in that all of the rotor devices mentioned can be arranged on a common rotary shaft.
• the centrifugal separator also has a suction effect and can therefore be easily integrated into a flow system as a driver for a slurry to be treated without additional pump units.
• FIG. 1 is a partially longitudinal sectional view of a centrifugal separator according to a preferred embodiment of the invention
• 2A-2C a detail of the centrifugal separator according to FIG. 1 in overall view (FIG. 2A), bottom view (FIG. 2B) and top view (FIG. 2C),
• Fig. 3 is a sectional view along the
• FIG. 4 in a view similar to Fig. 1
• FIG. 5 shows a centrifugal separator according to a third modified embodiment of the invention.
• Fig. 6 shows a centrifugal separator for the
• the reference numeral 1 in FIG. 1 relates to a tubular cylindrical housing which merges into a funnel-shaped base area 2 which tapers to a removal opening 3 at the lower end.
• the housing 1 defines a deposition chamber 4, into which a hollow shaft 5 projects coaxially to the central longitudinal axis and which ends with its lower axial open end at a suitable distance from the plane from which the funnel-shaped region 2 extends downward.
• a coupling device 7 is provided, which is connected to a drive device 8, for example in the form of an electric motor, to the hollow shaft 5 with a suitable rotation speed in rotation.
• the hollow shaft 5 is supported in a bearing-free manner only by the drive device 8. If desired, a suitable bearing arrangement could also be provided to support the hollow shaft 5 with respect to the housing 1.
• a mounting plate 12 is attached to an intermediate axial position of the hollow shaft 5, e.g. welded, which surrounds the hollow shaft 5 in a radial plane.
• a plurality of rotor blades 11 are attached to the underside of the mounting plate 12 at the same angular distance from one another and project radially outward from the hollow shaft 5 to close to the inner circumference of the housing 1.
• four rotor blades 11 are provided. However, more or less such rotor blades can also be provided.
• the rotor blades 11 form a cyclone rotor device which bears the general reference number 10 in FIG. 1 in order to force a liquid slurry introduced into the separation chamber 4 to make a circular movement along the inner wall of the housing 1.
• the heavier portions of the sludge will collect near the inner wall of the deposition chamber 4, while the lighter portions enter the hollow shaft 5 and can be discharged from there to the outside, which will be discussed in more detail later.
• a plurality of rotor blades 21 are attached to the top of the mounting plate 12, which, starting from the hollow shaft 5, radially outward in an essentially spiral shape to one point extend at a distance D from the central longitudinal axis of the hollow shaft 5 which is greater than the diameter d of an arc described by the outer ends of the rotor blades 11 of the cyclone rotor device 10 or the radial dimension of the deposition chamber 4.
• the rotor blades 21 can protrude by a suitable short dimension beyond the outer peripheral edge of the mounting plate 12.
• the ratio D: d is between about 1.25: 1 to 1.75: 1, most preferably about 1.50: 1.
• the rotor blades 21 are part of a transport rotor device which bears the general reference number 20 in FIG. 1 and which interacts with a stator device 22 which is shown in more detail in FIG. 3.
• the stator device 22 comprises a multiplicity of stationary guide elements 23, which extend in a radial plane below the plane of the rotor blades 21 of the transport rotor device 20, preferably in a spiral, from a radially outer location corresponding to the dimension D in FIG. 2A to a radially inner location, which essentially corresponds to the inner circumference of the housing 1.
• the guide elements 23 are aligned with their inner end regions preferably substantially tangential to the inner circumference of the housing 1.
• Passages 24 are defined between adjacent guide elements 23, via which the slurry can enter the deposition chamber 4.
• the guide elements 23 of the stator device 22 project beyond the peripheral edge of the mounting plate 12, so that a fluid connection is created between the stator device 22 and the transport rotor device 20.
• the radially outer regions of the rotor blades 21 of the transport rotor device 20 and the guide elements 23 of the stator device 22 are accommodated in a flange-shaped chamber 25 which is formed in an attachment housing which is arranged above the housing 1 and bears the general reference number 6 .
• the stator device 22 has the task of braking a rotational speed of the slurry caused by the transport rotor device 20, as a result of which the slurry is pressurized before it reaches the separation chamber 4 tangentially via the passages 24 and into the area of influence of the cyclone rotor device 10, where a circular movement is forced on it by the cyclone rotor device 10.
• the speed of rotation of the slurry in the separation chamber 4 is influenced by the effective area and speed of the rotor blades 11 of the cyclone rotor device 10, the throughput and by the tangential entry of the slurry into the separation chamber 4.
• the cyclone rotor device 10 and the transport rotor device 20 are mounted on the same hollow shaft 5 as the drive shaft, so that they rotate at the same speed. If desired, separate drive shafts could also be provided for the cyclone rotor device 10 and transport rotor device 20 in order to operate them at different speeds.
• the slurry as shown in FIG. 1, is introduced via an inlet connector 30 into an anteroom 31 of the attachment housing 6, which is connected to the transport rotor device 20.
• the slurry enters the centrifugal separator on essentially the same radial plane as it leaves it, as shown in FIG. 1.
• the inlet and outlet nozzles could also lie on different radial planes.
• the removal opening 3 are discharged to the outside continuously or at suitable time intervals.
• the removal opening 3 preferably has an adjustable opening width.
• Fig. 4 shows a modified simplified embodiment of a centrifugal separator according to the invention with particular suitability for the treatment of turbidity with easily separable foreign matter.
• the same or similar components as in the embodiment described above have the same reference numerals, increased by the number one hundred.
• This c embodiment differs from the one described above essentially in that the cyclone rotor device is omitted and, consequently, the circular movement solely due to the tangential introduction of the slurry into the deposition chamber 104 and Overpressure is caused, which is applied by the transport rotor device 120 and stator device 122 arranged upstream of the inlet.
• the transport rotor device 120 has a modified configuration in that the rotor blades 121 only extend to the outer circumference of the mounting plate 112, so that on the outside circumference of the mounting plate 112 an annular space 126 is defined in the top housing 106, into which the turbidity under the action of the transport rotor device 120 can flow in order to reach the area of influence of the stator device 122. It was found that these measures can improve the efficiency of the transport rotor / stator devices 120, 122. If desired, such a modified transport rotor device could also be provided in the embodiment of the invention according to FIG. 1.
• cylindrical section of the housing 101 is shortened by a suitable dimension compared to the previously described embodiment and the conical section 102 extending to the outlet opening 103 is correspondingly lengthened.
• centrifugal separators which are specially designed for the flotation fine separation of prefiltered slurries or sludges with a residual proportion of small-sized foreign substances remaining after prefiltration, e.g. 2 mm or less are suitable.
• Fig. 5 shows an embodiment of a flotation centrifugal separator, which with regard to the construction of the Feeding device for feeding the slurry, consisting of the inlet port 230 and the antechamber 231, which corresponds to the transport rotor device 220 arranged on the upstream side of the inlet into the separation chamber 205 with stator device 222 for pressurizing the slurry upstream and the cyclone rotor device 210 essentially corresponding to the embodiment according to FIG. 1, so that reference can be made to this.
• the same or similar components as in the embodiment described above have the same reference numerals, increased by the number two hundred.
• the transport rotor device 220 and the cyclone rotor device 210 are arranged on a common drive shaft 254, which is not used at the same time for removing a separated portion of the sludge to be treated. Furthermore, the effective area of the rotor blades 211 of the cyclone rotor device 210 can be reduced compared to the embodiment according to FIG. 1 by reducing the axial dimensions of the rotor blades.
• the housing 201 has a continuously cylindrical configuration, so that a likewise continuously cylindrical deposition chamber 204 is formed.
• a tubular member 255 with open ends axially penetrating the bottom 252 of the housing 201 projects into the interior of the deposition chamber 204 so that an open end of the tubular member 255 comes to lie at a suitable distance from the bottom 252 of the housing 201, while the other open end is arranged outside the housing 201.
• the tubular element 255 serves to capture the fine foreign matter components of the sludge which are separated off by means of the flotation separation described below.
• the liquid cleaned from the foreign substances or the clear run can be discharged via an outlet connection 253 which opens tangentially into the deposition chamber 204 near the bottom 252 of the housing 201.
• a device for introducing a liquid containing a suitable gas, such as air, into the deposition chamber 204 is provided.
• the device comprises an annular distribution line 256 which surrounds a peripheral region of the housing 201, in which the housing wall is penetrated by perforations 257.
• An inlet port 258 also opens into the distribution line 256. The liquid with the gas can therefore be conducted into the interior of the deposition chamber 204 via the inlet port 258, the distribution line 256 and the perforations 257.
• the liquid is preferably one in which the gas is in the form of microbubbles with a dimension of e.g. 100 ⁇ m or less is distributed.
• Such liquids permeated with micro gas bubbles can e.g. can be created with a device which bears the reference number 259 in FIG. 5 and can be designed according to DE-A-3733583, to which reference can therefore be made.
• the device 259 is connected to a fumigation container 260, into which the liquid to be fumigated and a suitable gas can be introduced separately and pressurized.
• Water can be used as the liquid. As shown, this can also be a branched-off part of the clear run discharged via the outlet connection 253, in that it runs into the gassing container 260 via a pump 261 passed, charged with the gas there and introduced into the device 259 for generating the micro gas bubbles.
• the micro gas bubbles introduced into the slurry in the manner described above combine due to their surface tension with the fine, floatable foreign matter fractions of the slurry, which therefore preferentially accumulate under the acting centrifugal forces near the central longitudinal axis of the centrifugal separator.
• the micro gas bubbles with the adhering foreign matter portions can therefore be discharged from the deposition chamber 204 via the central tubular element 255, while the clear run at the outlet connection 253 can be removed.
• the gas could also be introduced directly into the deposition chamber 204 in order to generate gas bubbles in the slurry.
• the gases should be introduced via a diffuser ring (not shown) made of a fine-grained sintered metal, which would have to be provided instead of the distribution line 256.
• the cyclone rotor device 210 could be omitted, so that the circular movement of the slurry would be based solely on the pressure-increasing effect of the interacting transport rotor and stator devices 220, 222 and the tangential introduction of the slurry into the deposition chamber 204, as in the embodiment according to FIG. 4 .
• the discharge of the micro gas bubbles could be included adhering foreign matter in a similar manner as in the embodiments of the invention according to FIGS. 1 and 4 take place via a central hollow shaft against the effect of gravity, which would simultaneously represent the common axis of rotation of the transport rotor device 220 and cyclone rotor device 210.
• the fourth embodiment of the invention comprises a continuously cylindrical housing 301 which defines a likewise cylindrical deposition chamber 304.
• a transport rotor device 320 and a cooperating stator device 322 are provided for pressurizing the slurry, the construction and mode of operation of which correspond to that of the embodiment according to FIG. 1, so that a new description is unnecessary.
• a cyclone rotor device is omitted.
• a feature of the centrifugal separator according to FIG. 6 is a foam destruction device, which has the general reference number 370.
• the foam destruction device 370 comprises a plurality of rotor blades 371 which can be rotated about a central axis, which preferably coincides with the axis of rotation of the rotor blades 321 of the transport rotor means 320, and which are arranged in a space 372 in a housing 306 arranged above the separation housing 301.
• the space 372 is arranged above a space 373 in the top housing 369 containing the transport rotor device 320 and stator device 322, in FIG which the slurry to be treated can be introduced via an inlet connector 374.
• a slurry in which micro gas bubbles are dispersed can be introduced via the inlet connector 374.
• the micro gas bubbles can, as indicated at 359, be introduced into the slurry by means of a device as described in connection with the embodiment according to FIG. 5.
• the spaces 372 and 373 in the top housing 369 are sealed off from one another, and further the upper space 372 is subdivided into a lower region 372 'containing the rotor blades 371 of the foam destruction device 370 and an upper region 372' 'which is close to the hollow shaft 305 with the lower one Area 372 'is in fluid communication.
• a foreign matter outlet connection 376 opens into the lower region 372 '.
• the peripheral wall of the attachment housing 369 is penetrated along the upper region 372' 'by a plurality of circumferentially distributed perforations 377 which connect the interior of the upper region 372' 'to a gas outlet connection 378 in order to to be able to remove the gaseous constituents removed from the foreign substances.
• the rotor blades 371 of the foam destruction device 370 can be mounted on the same axis of rotation as the rotor blades 321 of the transport rotor device 320.
• the axis of rotation is designed as a hollow shaft 305, which projects axially into the deposition chamber 304 and has a lower open end into which the separated foreign substances adhering to the gas bubbles can enter, from where they rise inside the hollow shaft 305 and into the space 372 of the foam destruction device 370 and thus reach the area of influence of the rotor blades 371.
• An outlet connection 380 which opens tangentially near the bottom 379 of the separation housing 301 serves to discharge the liquid portions of the cloudy or clear run freed from the foreign substances.
• the foreign substances adhering to the gas bubbles which have entered the space 372 are set in a circular motion by the rotor blades 371, so that the heavier foreign substances are separated from the gas bubbles due to centrifugal effects and accumulate on the inner circumference of the lower area 372 ' .
• the gas bubbles rise upwards into the upper area 372 '', from where they can be discharged to the outside in the aforementioned manner.
• the sludge in the separation chamber 304 could also be treated in the presence of gas bubbles by introducing the gas into the separation chamber 304 separately from the slurry in accordance with the embodiment according to FIG. 5.
• a cyclone rotor device similar to the embodiment of the invention of FIG. 1 could be provided.
• the rotor vanes 371 of the foam destruction device 370, the rotor vanes 321 of the transport rotor device 320 and the rotor vanes of the added cyclone rotor device would be mounted on the driven hollow shaft 305 for rotation together by the drive device 308.
• independent drive shafts can also be provided for driving said rotor blades.

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Applications Claiming Priority (6)

Related Child Applications (1)

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Cited By (4)

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Citations (6)

• 1997
  • 1997-04-17 ES ES97919374T patent/ES2162280T3/es not_active Expired - Lifetime
  • 1997-04-17 AT AT97919374T patent/ATE203431T1/de active
  • 1997-04-17 WO PCT/EP1997/001913 patent/WO1997040944A1/de active IP Right Grant
  • 1997-04-17 AU AU23873/97A patent/AU2387397A/en not_active Abandoned
  • 1997-04-17 DE DE59704134T patent/DE59704134D1/de not_active Expired - Lifetime
  • 1997-04-17 EP EP97919374A patent/EP0904156B1/de not_active Expired - Lifetime
  • 1997-04-17 JP JP53851197A patent/JP4047386B2/ja not_active Expired - Lifetime
• 1999
  • 1999-09-17 HK HK99104026A patent/HK1018889A1/xx not_active IP Right Cessation

Patent Citations (6)

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