Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F27/00—Mixers with rotary stirring devices in fixed receptacles; Kneaders
  • B01F27/27—Mixers with stator-rotor systems, e.g. with intermeshing teeth or cylinders or having orifices
  • B01F27/272—Mixers with stator-rotor systems, e.g. with intermeshing teeth or cylinders or having orifices with means for moving the materials to be mixed axially between the surfaces of the rotor and the stator, e.g. the stator rotor system formed by conical or cylindrical surfaces
• • 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
  • B03D3/00—Differential sedimentation
  • B03D3/06—Flocculation
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F27/00—Mixers with rotary stirring devices in fixed receptacles; Kneaders
  • B01F27/27—Mixers with stator-rotor systems, e.g. with intermeshing teeth or cylinders or having orifices
  • B01F27/272—Mixers with stator-rotor systems, e.g. with intermeshing teeth or cylinders or having orifices with means for moving the materials to be mixed axially between the surfaces of the rotor and the stator, e.g. the stator rotor system formed by conical or cylindrical surfaces
  • B01F27/2723—Mixers with stator-rotor systems, e.g. with intermeshing teeth or cylinders or having orifices with means for moving the materials to be mixed axially between the surfaces of the rotor and the stator, e.g. the stator rotor system formed by conical or cylindrical surfaces the surfaces having a conical shape
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F27/00—Mixers with rotary stirring devices in fixed receptacles; Kneaders
  • B01F27/27—Mixers with stator-rotor systems, e.g. with intermeshing teeth or cylinders or having orifices
  • B01F27/272—Mixers with stator-rotor systems, e.g. with intermeshing teeth or cylinders or having orifices with means for moving the materials to be mixed axially between the surfaces of the rotor and the stator, e.g. the stator rotor system formed by conical or cylindrical surfaces
  • B01F27/2724—Mixers with stator-rotor systems, e.g. with intermeshing teeth or cylinders or having orifices with means for moving the materials to be mixed axially between the surfaces of the rotor and the stator, e.g. the stator rotor system formed by conical or cylindrical surfaces the relative position of the stator and the rotor, gap in between or gap with the walls being adjustable

Definitions

• the invention relates to a flocculation apparatus for conditioning colloidal suspensions with a suspension inlet, a suspension outlet and with an inner cone, which is mounted centrally in a conical outer housing, the inner cone and / or the outer housing being rotatable relative to one another and a gap space between the inner cone and the outer housing for the flow of suspensions.
• the suspension is conventionally mixed with a flocculant and / or flocculant and mechanically processed in a flocculent.
• the flocculation itself is in one
• the .5 rapid mixer unit carried out so that the flakes are formed.
• the flakes are shaped in a flake apparatus, the resulting flakes being pelletized and rounded off by shear forces and flake erosion, so that the desired property of the flakes, e.g. B. Improve the drainage capacity or thickening again
• the flocculant and / or flocculant! 5 is dispersed in a suspension by turbulent flow movements.
• the formation and adsorption reaction times of the flocculation chemicals are very short and it is important to ensure that the substances are mixed in homogeneously in order to optimize the flocculation results.
• the flocculants and / or flocculants are conventionally mixed in with stirred tanks or with tube reactors with plug flow, such as injection mixers, inline turbo mixers and pumps.
• the sewage sludge flow runs from the top of the cone base down to the cone tip, with flocculants being inserted into the cone gap space of the pelletizing reactor.
• the conical pelleting zone the flake pellets roll in a circle on the pelleting surface.
• the conditioning process is controlled by a cone stirrer to generate a circulation flow.
• the essential parameters such as particle size distribution, porosity or the specific surface of the sewage sludge, are set reproducibly.
• the object of the invention was therefore to create a flocculation apparatus which can be variably adapted to the ambient conditions.
• the object is achieved with the generic flocculation apparatus in the form of a cone stirrer in that the inner cone and / or outer housing is axially displaceably mounted and an actuator for controlled axial displacement of the inner cone and / or outer housing is operatively connected to the inner cone and / or outer housing.
• the reaction volume in the flocculation apparatus is thus variable and can be adapted to the ambient conditions. Due to the axial displacement of the inner cone and / or outer housing, the gap width of the flow space between the inner cone and the outer housing can be easily adjusted. As a result, both the dwell time at different volume flows can be kept constant and the flow regime can be adapted to changing mass flows.
• the suspension inlet is preferably in the area of the cone base of the inner cone and outer housing and the suspension outlet is in the area of the cone tip of the inner cone and outer housing.
• the suspension flow preferably runs from the cone base to the cone tip. It has been found that the flocculation results are reproducible and optimal with such a flow direction.
• the surface of the inner cone and / or the inner surface of the outer housing should be profiled, for example, by milled longitudinal grooves. As a result, the flow is implemented faster.
• the axis of rotation of the inner cone is preferably approximately perpendicular, the suspension inlet being arranged above the suspension outlet. In this way, a natural suspension flow is forced from top to bottom.
• the angle of inclination of the inner cone should be relatively small and should be about 2 to 30 degrees.
• conventional cone stirrers have an inclination angle of 35 degrees and cylinder stirrers have an angle of 0 degrees. It was recognized that optimal reproducible and controllable flocculation results can be achieved with a small inclination angle.
• a mixer for generating a highly turbulent suspension flow is preferably arranged immediately before the inlet of the suspension.
• the mixer is preferably integrated with the flocculation apparatus in one device.
• the conditioning of colloidal suspensions such as e.g. B. sewage sludge, with the flocculation apparatus according to the invention is preferably carried out by:
• the speed of the inner cone and / or outer housing can be regulated as a function of a flake size distribution.
• FIG. 1 sectional view of the flocculating apparatus with axially displaceable inner cone
• Figure 2 - sectional view of a rapid mixer for generating a highly turbulent suspension flow.
• FIG. 1 shows the flocculation apparatus 1 according to the invention in a sectional view.
• the flocculation apparatus 1 essentially consists of a conical outer housing 2 and an inner cone 3, which is arranged centrally in the outer housing 2.
• the inner cone 3 is rotatably mounted on a driven shaft 4.
• a suspension stream is introduced into the flocculation apparatus 1 through a suspension inlet 5 in the region of the cone base of the inner cone 3.
• the suspension then flows together with the flocculant and / or flocculant in the gap between the inner cone 3 and the outer housing 2 in the axial direction from the cone base to the cone tip and flows out through a suspension outlet 6 in the region of the cone tip.
• the angle of inclination of the inner cone 3 and correspondingly the angle of inclination of the outer housing 2 is relatively small and is in the range of approximately 2 to 30 degrees. Since the radii of the inner cone 3 for the suspensions through which flow flows change during the flow, the centrifugal forces generated are not constant due to the changing circumferential speed along the driven shaft 4. In contrast to cylindrical stirrers, the flow conditions are not uniform over the length of the circular or conical gap. If the flocculation apparatus 1 is flowed through by the cone base of the inner cone 3 in the direction of the truncated cone tip, the suspension is initially subjected to greater shear forces when entering the cone base, since the basic flow is greatest there due to the higher peripheral speed. The shear forces decrease continuously in the direction of the decreasing radii of the inner cone 3, so that flake structures that have already been formed are not or only barely destroyed later.
• the outer housing 2 is considerably longer than the inner cone 3, so that the inner cone 3 is axially displaceable in a wide range.
• the flocculation apparatus 1 can also be constructed in such a way that the outer housing 2 can be displaced axially relative to the inner cone 3. It is also conceivable that the outer housing 2 can be rotated.
• the axial displacement of the inner cone 3 relative to the outer housing 2 means that the gap width between the inner cone 3 and the outer housing 2 can be variably adjusted.
• the axial displacement can be implemented, for example, with a spindle stroke drive as an actuator, which interacts with the shaft 4.
• the motor shaft of a drive motor is fixedly connected to a guide sleeve which is operatively connected to the shaft 4 by means of a feather key connection, so that the shaft 4 can be displaced axially relative to the motor shaft.
• the shaft 4 is preferably mounted in an angular contact ball bearing 7, the bearing housing preferably being square in order to guide it in the groove of a guide rail. This ensures that after the coupling by the angular contact ball bearing 7, there is no longer any rotation which could act on the spindle lifting drive.
• FIG. 2 shows a rapid mixer 8 with a suspension inlet 9 and a suspension outlet 10.
• the suspension outlet 10 is immediately in front the suspension inlet 5 of the flocculation apparatus 1 switched.
• the rapid mixer 8 has a main rotor 11 through which the outside flows inwards, which is equipped with employed, blade-shaped blades which carry the suspension in the conveying direction.
• the flocculant and / or flocculant is fed to the rapid mixer 8 via four nozzles 12 distributed over the circumference.
• the medium After mixing in the main rotor 1 1, the medium enters an intermediate stator 13, the jacket of which is extended beyond the area of the main rotor 1 1 to reduce wear.
• An auxiliary rotor 14 is provided in the flow direction behind the stator 1 3. This arrangement of series-connected main rotor 1 1, stator 1 3 and auxiliary rotor 14 ensures homogeneous mixing of the medium within a certain dwell time.
• the rotor speed should be continuously adjustable up to about 2800 N / min.
• the conditioning process can be regulated with four different degrees of freedom with the aid of the arrangement of a rapid mixer 8 connected in series and a flocculation apparatus 1.
• the flocculant and / or flocculant is mixed homogeneously in the rapid mixer and total flocculation of the suspension is carried out.
• the amount of flocculant and / or flocculant introduced and the amount of mixing energy can be variably adjusted by adjusting the speed of the rapid mixer 8.
• the flocculation device discretizes the flocculation.
• the different sized aggregates of the total flocculation are eroded, reflocculated, compacted and evened out by shear stress.
• the speed and the reaction volume of the apparatus can be changed in the flocculating apparatus 1.
• the flakes can be exposed to an adapted shear force regime over a wide range.
• the setting of the rapid mixer 8 and of the flocculation apparatus 1 is thus dependent on the volume flow and in particular the size of the flakes and the size of the flakes.
• the flake size and the flake size distribution have namely z.
• the rapid mixer 8 is now regulated so that the flocculant and / or flocculant is mixed homogeneously and completely with the suspension. Sufficient energy must flow into the suspension flocculant and / or flocculant mixture so that each suspension particle has the possibility of combining with flocculant and / or flocculant. On the other hand, only so much energy may be used that the flakes are not destroyed again during or immediately after their formation. For this purpose, the speed must be set accordingly in a known and scientifically investigated manner.
• the speed and the gap width between the inner cone 3 and the outer housing 2 are varied in the flocculating apparatus 1.
• the change in gap width causes both a change in volume and thus a change in the axial parameters such as dwell time, axial speed, axial Reynolds number and axial camp number, as well as a change in the radius ratio and thus a change in the Taylor and rotational camp number.
• the flow conditions can thus be variably adjusted over a wide range.
• the flake size distribution is preferably optically determined and the rapid mixer 8 and the flocculation apparatus 1 are regulated such that an optimal flake size distribution results. This enables conditioning in a closed, self-adapting control system.

Landscapes

• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Separation Of Suspended Particles By Flocculating Agents (AREA)
• Mixers Of The Rotary Stirring Type (AREA)
• Diaphragms For Electromechanical Transducers (AREA)
• Polarising Elements (AREA)
• Application Of Or Painting With Fluid Materials (AREA)

Applications Claiming Priority (3)

Publications (2)

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ID=7701230

Family Applications (1)

Country Status (7)

Cited By (1)

Families Citing this family (4)

Family Cites Families (15)

• 2001
  • 2001-10-02 DE DE10148760A patent/DE10148760A1/de not_active Withdrawn
• 2002
  • 2002-09-26 DK DK02779131T patent/DK1432502T3/da active
  • 2002-09-26 AT AT02779131T patent/ATE299394T1/de active
  • 2002-09-26 JP JP2003534064A patent/JP4386726B2/ja not_active Expired - Fee Related
  • 2002-09-26 WO PCT/DE2002/003654 patent/WO2003031040A1/fr active IP Right Grant
  • 2002-09-26 US US10/491,289 patent/US7135112B2/en not_active Expired - Lifetime
  • 2002-09-26 EP EP02779131A patent/EP1432502B1/fr not_active Expired - Lifetime
  • 2002-09-26 DE DE50203636T patent/DE50203636D1/de not_active Expired - Lifetime

Non-Patent Citations (1)

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