DE19915735A1 - Flotation assembly to separate suspension into fractions which are rich and poor with separated matter comprises flotation column with center inflow and blades to divert low fraction into collection zone - Google Patents

Abstract

The flotation system (10a), to separate a suspension into fractions which are rich and poor has a suspension inflow (22) into the separation tank column (28) which gives a central and vertical main flow (30). Blades (32) are arranged radially outside the main flow. To give a fraction with a low matter content, a flow is directed outwards and at a downwards angle to a collection zone (18), into a ring collection channel (34) for the fraction which has a low material content. The separation tank has a circular or polygonal cross section. Or it has a general funnel shape, with an upwards expanding cross section. A further assembly of blades, stacked over each other, forms a cascade structure radially outside the collection channel. The collection channel is between the downstream edges of the initial blades and the upstream edges of the second set of blades. Inflow openings are at the lower end of the collection channel, for the introduction of chemicals and/or bubble fluid mixtures. A filtration zone (40) is radially outside the collection channel, to hold filtration particles of active carbon. The system has a filtrate outlet and a filter material outlet, where the filtration particles move in a counter flow to the filtrate flow in the filtration zone to the regeneration unit (44) at the opposite end, and are recirculated as regenerated particles. A number of blade flotation units and/or filtration units are assembled in an array outwards and in succession. Separate outlets are between them, to take off different fractions. Two or three blade flotation units are deployed as shells, radially outwards, with two or three filtration units outside a flotation unit. The blades have the shape of a closed conical ring, at a pitch angle of 10-40 deg to the horizontal, and preferably 20-30 deg . In the direction of the flow of the low-content fraction, the blades have a length which is 1-4 times the width of the main flow channel defined by the inner edges of the blades. The gap between the blades increases upwards from below. At least part of the blades is corrugated. At least part of the blades is a multilayer honeycomb structure, with two outer layers and linking structures between them, preferably forming passage flow channels between the outer layers. At least part of the blades is a micro-porous membrane, and at least a part of the blades forms a curvature. The suspension inflow has a channel for the incoming suspension into the flotation assembly, with a radial outlet system to give an outflow in a radial direction, covered by a central passage preferably covered by a conical dome, so that the suspension flows centrally into the flotation tank. The radial unit has a horizontal beating plate (26), to deflect the suspension flow radially, The radial unit has a number of radial outflows (24) in a discrete array round the circumference. A take-off unit (16) for the fraction with a high content of matter is over the separation tank, with a passage aligned with the main flow. It has at least one impeller system to pass the rich fraction through a reject outlet, using a rotating conveyor screw or spatial paddles (56) in a horizontal channel (52). The flotation action is non-selective, using a pressure relief flotation with a bubble flow at the suspension inlet. Or the flotation is selective, with a feed of chemical additives at the suspension flow inlet.

Description

The invention relates to a flotation device for separating of substances or mixtures of substances from suspensions Formation of at least one substance-rich and low-substance fraction with a columnar separation tank with a Sus boarding entrance as well as several diagonally arranged one above the other arranged slats, a first exit for the low-cloth Fraction and a second one arranged in the upper area Output for the high-content fraction includes.

Such a flotation device is from the publication "Wochenblatt für Papierfabrikation", 1998, Issue 13, page 660 known. Such an arrangement has over conventional union flotation arrangements with essentially horizontal Suspension flow the advantage of a much lower Space requirements for the installation, whereas he for it required significantly greater height is usually not critical. At In this arrangement, a suspension flows along the outside walls of a cylindrical container upwards, the Clear water between several spaced separating cones radially enters and exits a central manifold internally can be performed. A disadvantage of this previously known arrangement However, is that the clear water flow an increasing due to the direction of flow Experiences flow velocity, which actually causes the particles flowing at the top have a tendency to getting carried away. This reduces the efficiency of the Separation. Another disadvantage is that successive separation processes, be it flotation processes or coupling of flotation and filtration processes requires separate installation of separate assemblies that then be closed in a row.

Proceeding from this, the object of the invention is to create a generic flotation device, which avoids the disadvantages mentioned above and in particular  through an effective separation of the desired substances of Sus pension into a low-substance and a substance-rich fraction draws. In addition, the arrangement is also said to be compact functional series connection of several isolators possible.

This object is achieved by the specified in claim 1 Features resolved. There are advantageous further developments from the subclaims.

The main advantages of the invention are that by arranging the vertical flow radially upwards and the arrangement of the fins radially outside the main flow the flow of the lean fraction radially outward ge is aimed and thus increasingly slows down, which is a better separation of the particles. Another advantage is that the low-fraction on the outer circumference, that is, collected behind the downstream edges of the fins , which means that additional separation stages are required with a small footprint can be provided, be it as additional flotation or as filtration levels. Through a targeted cascade Sequence of several separation stages, in particular of Flo stages of different principles, (pressure release selection and physical selection procedures) can be several Fractions of different substance contents are generated. The associated additional space requirement in the radial direction is relatively small.

Most conveniently, the separation tank has a circular cross cut. If necessary, however, there are also other cross-sections shapes possible, especially a polygonal, especially three angular or square cross section.

The separation tank is usually cylindrical det be. If there is a large accumulation due to technical reasons of the substance-rich fraction in the upper area can be a funnel-like or conical formation of the main flow  nals, i.e. a radial reset of the ones above the slat leading edges should be appropriate.

According to an advantageous development of the invention, ra dial at least one other dial outside the collection channel order of several superimposed second slats arranged in cascade, with the collecting channel between the downstream edges of the former and the upstream edges of the second fins is formed. This arrangement enables an improved separation of the sus pension and in particular the derivation of a first sub-fraction tion after the first flotation step and the derivation of the Residual fraction after the second flotation step.

Here are preferably at the lower end of the collecting channel flow openings for the introduction of chemicals and / or Bubble fluid mixtures provided a selective (in particular by means of collective adsorption or hydrophobization) and / or a non-selective flotation principle for use bring to.

Alternatively or additionally, according to a further advantage adhere to the invention outside the collecting channel one of them loaded with filtration particles ter filtration room provided. This is a substance separation on the filtration principle possible, which only one has very little additional radial space. Here a particularly effective filtration can be achieved if a filtrate outlet and a filter material outlet are provided are, the filtration particles in countercurrent to the Fil walk through the filtration room and thereby to the Re generation removable and active at the opposite end nerated state are supplied again.

In all the embodiments described above, advantageous usually between the individual flotation and / or filtra stages separate outlets for the removal of under different political groups.  

According to another advantageous embodiment of the invention the lamellae in the form of closed conical rings. A be Particularly good separation of the groups results when the Slats an angle of inclination to the horizontal of 10 ° -40 °, preferably have 20 ° -30 °. It is also advantageous if the length of the fins in the direction of flow of the material men fraction is 1 to 4 times the width of the through the inner edges of the fins delimited main flow channel. The distance between adjacent slats can be un to increase the different currents mation and consistency ratios in the lower or upper Be range of the separation tank.

At least some of the slats can expediently be used be wavy, the waves in the circumferential direction run, so that this does not affect the currents The low-fraction fraction is connected. This training has the advantage of a significantly higher stiffness of the La mellen.

A particularly advantageous development of the invention provides before that at least part of the slats as multilayer, before preferably honeycomb structure with two outer layers and in between arranged connection structures is formed where with preferably continuous flow channels between the Outer layers are formed. This results in an essential higher strength of the slats.

Another development of the invention provides that the Sus pension inlet comprises a supply line which with an Ra dial exit device for generating an outflow in radial direction and this is connected from one to one centric passage, preferably conical dome is covered so that the suspension is centered over the passage enters the separation tank. In this way, one favorable introduction of the suspension into the lower area of the Separation tanks causes.  

The invention is described below with reference to the accompanying drawing further explained. It shows:

Figure 1 is a schematic longitudinal sectional view through a first embodiment of the invention with a Flo tations- and a filtration stage.

Figure 2 is a schematic longitudinal sectional view through a second embodiment of the invention with two successive flotation.

Fig. 3 shows schematically two alternative forms for the lamellae; and

Fig. 4 schematically shows an arrangement with three successive flotation steps.

In Fig. 1, a first embodiment of the invention is shown schematically in axial longitudinal section, thus a flotation device 10 a. This includes, in terms of modules, an inflow unit 12 , a material separation unit 14 , a discharge unit 16 for the high-fraction and a first collection area 18 for the low-fraction. Furthermore, a second collecting area 20 for solid particles is also seen.

In the inflow unit 12 leads a feed line 22 for the suspension to be separated, which in the embodiment shown lead into a plurality of separate or an annular outlet 24 which are provided with baffle plates 26 . In the feed line 22 or in the area of the outlets 24 , a feed line (not shown) for a liquid and / or chemical substances mixed with gas bubbles is preferably provided in order to effect non-selective or selective flotation.

The material separation unit 14 is essentially formed by a cylindrical separating tank 28 , in the central region of which a vertical main flow channel 30 is formed, which leads from the inflow unit 12 to the discharge unit 16 . Radially outside the main flow channel 30 , a number of axially spaced lamellae 32 are provided one above the other, which are annularly conical and define between them a radially outward and obliquely downward flow for the lean fraction to the first collecting area 18 . This ring-shaped first collecting region 18 , which is formed between the wall of the separation tank 28 and the downstream edges of the fins 32 , leads to a collecting space 34 arranged above the uppermost fin 32 for a first low-fraction, in which a first collecting tube 36 for this first low-fraction is seen before.

A simple one-step embodiment of the invention would get along with the assemblies shown so far, the ste manifold 36 in such a simple embodiment not necessarily above but also elsewhere, for. B. can be provided below.

The embodiment shown in FIG. 1 comprises, in addition to the previously discussed flotation stage, a filtration stage which will now be described.

Radially outside the wall of the separation tank 28 concentrically, a filter outer wall 38 is seen at a certain distance, so that an annular cylindrical filter chamber 40 is formed between the two. The filter chamber is filled with a filter material, preferably sand of a certain consistency or other filter substances such as activated carbon or mixtures thereof.

This filter chamber 40 comprises in its upper end region a second collecting pipe 42 for a second low-fraction, which is obtained after a flotation and a subsequent filtration step. Above the filter space 40 , a filter material regeneration unit 44 , not shown, is provided, which has the task of cleaning or regenerating filter material and which promotes the regenerated filter material into the filter space 40 . The filter material passes through the filter chamber 40 and arrives in a discharge channel 46 , from where it is supplied to the filter material regeneration unit 44 again in the used state via the schematically indicated line 48 . The filter material regeneration unit 44 includes at least one discharge line 47 for a second substance-rich fraction, which is obtained by separating the material from the filter material located in the filter space 40 during its regeneration.

The filter chamber 40 is connected via one or more connection openings 50 to the first collecting area 18 , via which the fraction enters the filter area which has already passed through the flotation area and is not discharged via the first collecting pipe 36 .

The discharge unit 16 essentially consists of a widening collecting channel 52 for the substance-rich fraction, which leads to one or more collecting channels or pipes 54. In order to convey the rich, mostly mud-shaped fraction bes water from the collecting channel 52 into the collecting trough 54 , one or more conveying devices 56 , shown as rotating paddle arrangements, are provided.

Below the material separation unit 14 , preferably functionally combined with the inflow unit 12 , a collecting device 58 is provided for the sedimentation of heavy particles, which opens into a sediment outlet 60 .

Now the operation of this first embodiment further illustrated the invention.

Via the feed line 20 a suspension flows, the chemical substances and / or gas bubbles can be added to the outlets 24 and is deflected by means of the baffle plates 26 in such a way that when entering the inflow unit 12 , a horizontal flow initially occurs, which occurs when entering the main flow channel 30 goes into a radial main flow. This process is supported by the conical shape of the lowest slat 32 . The type of generation and the location of the introduction of gas bubbles or the number and size of the bubbles determine the type of flotation (pressure release or dispersion flotation).

The desired substances from the suspension separate under the action of the supplied gas bubbles and / or chemical substances on the way up into a substance-rich fraction flowing upwards and a substance-poor fraction flowing through the lamellae 32 ra dial. The material-rich fraction, which is usually sludge-shaped, can be discharged via the collecting troughs 54 after collection in the discharge unit by means of the conveying devices 56 . This high-fraction can either contain undesirable substances such as. As ash or ink particles, in the waste paper preparation (is then usually referred to as reject fraction) or valuable substances, for. B. in ore or mineral extraction.

The fraction of poorer material branched off radially on the outside by the main flow in the main flow channel 30 flows through the annular spaces formed between the fins 32 into the first collecting area 18 . If - unlike in the embodiment shown in FIG. 1 - no further filtration process follows - this is the desired low-fraction which is removed via the first collecting tube 36 .

If, however, a more effective material separation is desired at least for a part of the fraction located in the first collecting area 18 , this partial fraction flows through the connection openings 50 into the filter space 40 and from there in the vertical direction upwards, in countercurrent to the filter material flow that flows from the top runs below. About the second manifold 42 , a second low-fraction can then be removed, from which the filtered-out fraction can be removed from the mel tube 36 via the first sam, which are in turn removed via the discharge line 47 from the system. The filter material circulates between the filter space 40 and the filter material regeneration unit 44 . The heavy particles resulting from the separation, e.g. B. iron parts fall into the sediment collector 58 and then into the sediment outlet 60th

FIG. 2 shows an alternative embodiment of the invention in the form of a flotation device 10 b, which differs from the embodiment according to FIG. 1 in that two flotation stages are arranged one behind the other. The same reference numerals designate the same components. In this regard, to avoid repetition, reference is made to the above description, insofar as this relates to the first flotation step.

The embodiment of FIG. 2 differs from that of FIG. 1 in that a second group of fins 62 is arranged radially outside the first collecting area 18 , radially outside of which a third collecting area 64 is provided. Although in the illustrated embodiment the first slats 32 and the second slats 62 have the same distances and inclinations, it is not necessary. Rather, the number, shape, inclination, etc. of the second slats 62 can be selected independently of that of the first slats 32 depending on the specific conditions.

In this embodiment, a feed pipe 66 is provided at the lower end of the first annular collecting area 18 , through which a liquid or chemical substances mixed with gas bubbles are supplied in order to achieve certain flotation conditions in the most collecting area 18 .

Above the third collecting area 64 , a third collecting pipe 68 is arranged for collecting a second low-fraction, which, in contrast to the fraction which can be removed via the first collecting pipe 36, is further freed from substances to be separated.

Insofar as there is talk of collecting pipes 36 , 42 , 68 in this context, any form of collecting device should be understood. In particular, it can also be a matter of a plurality of tubes or openings which are provided in walls and only open into collecting tubes outside the wall. In FIGS. 3a and 3b are two forms of slat 32, illustrated 62, instead of simple flat shapes are appropriate. In Fig. 3a a honeycomb structure with two outer surfaces 70 a and 70 b can be seen, between which connecting struts 72 are provided, the gray areas are intended to represent shadows. Preferably, the cavities formed between adjacent connecting struts 72 are formed by common lines via which part of the flow can also take place. In Fig. 3b, a wave-like training of the lamellae 32 , 62 is shown, the flow direction being indicated by an arrow, that is to say parallel to the wavefront.

An arrangement of three successive flotation stages is shown schematically in FIG. 4, which would look similar to the embodiment of FIG. 2, except that 64 further lamellae would be radially outside the third collecting area. The central axis a, not shown in FIGS. 1 and 2, shows that one side is not shown completely here. Outside of the third collecting area 64 , additional slats 74 of a further flotation stage are provided in this embodiment, which preferably have a different spacing between adjacent slats. Radially outside of the fins 74 , a fourth fourth chamber 76, which is only schematically indicated, is then seen for an even lower-fraction.

Claims (29)

1. Flotation device for separating substances or mixtures of substances from suspensions to form at least one substance-rich and low-substance fraction with a column-like separation tank which has a suspension inlet at the bottom and a plurality of diagonally arranged lamellae arranged one above the other, a first outlet for the substance-poor fraction and an upper region Neten second outlet for the high-content fraction, characterized in that the suspension inlet causes a central, vertically directed main flow, the lamellae being arranged radially outside the main flow and causing an outward and obliquely downward flow for the low-content fraction, and a ring-shaped collecting channel for the low-fraction is formed radially outside the lamellae. 2. Flotation device according to claim 1, characterized indicates that the separation tank is circular or polygonal cross-section. 3. Flotation device according to claim 1, characterized records that the separation tank was essentially trich ter-like with a cross section widening towards the top is trained. 4. Flotation device according to one of the preceding An sayings, characterized in that radially outside the Collection channel at least one further arrangement of several second slats provided one above the other in cascade is arranged, the collecting channel between the stream downward edges of the first mentioned slats and the upstream edges of the second fins are formed is.   5. Flotation device according to claim 4, characterized records that inflow at the lower end of the collecting duct openings for the introduction of chemicals and / or Bubble fluid mixtures are provided. 6. Flotation device according to one of the preceding An sayings, characterized in that radially outside the Collecting channel one of these, with filtration particle-filled filtration space is provided. 7. Flotation device according to claim 6, characterized records that a filtrate outlet and a filter material outlet is provided, the filtration particles in Counterflow to the filtrate flow through the filtration room hiking and thereby removable for regeneration and on ent opposite end in the regenerated state again are feasible. 8. Flotation device according to one or more of the An sayings 4 to 7, characterized in that several La cell flotation arrangements according to one of claims 1 to 3 and / or filtration arrangements according to claim 6 are arranged one behind the other. 9. flotation device according to claim 8, characterized records that between the individual flotation and / or Filtration stages separate outlets to remove different fractions are provided. 10. Flotation device according to claim 8, characterized indicates that two or three lamellar flotation arrangements now are arranged radially one behind the other in a shell-like manner. 11. Flotation device according to claim 8, characterized records that radially outside a lamella flota tion arrangements two or three filtration arrangements are provided.   12. Flotation device according to one of the preceding claims che, characterized in that the lamellae the shape have closed conical rings. 13. Flotation device according to one of the preceding claims che, characterized in that the slats have a Nei angle to the horizontal of 10 ° -40 °, preferably Have 20 ° -30 °. 14. Flotation device according to one of the preceding claims che, characterized in that the length of the slats 1 to 4 times in the direction of flow of the lean fraction is as large as the width of the through the inner edges of the Slats limited main flow channel. 15. Flotation device according to one of the preceding claims che, characterized in that the distance between be neighboring slats increases from bottom to top. 16. Flotation device according to one of the preceding claims che, characterized in that at least part of the Slats are wavy. 17. Flotation device according to one of the preceding claims che, characterized in that at least part of the Slats as multi-layer, preferably honeycomb Structure with two outer layers and arranged in between Connection structures is formed, preferably continuous flow channels between the outer layers are formed. 18. Flotation device according to one of the preceding claims che, characterized in that at least part of the Slats are designed as a microporous membrane. 19. Flotation device according to one of the preceding claims che, characterized in that at least part of the Slats are arched.   20. Flotation device according to claim 1, characterized records that the suspension inlet is a feed line comprises with a radial outlet device for Er Generation of an outflow connected in the radial direction and this is one with a central passage provided, preferably conical dome is covered, so that the suspension in the middle of the passage in the Sepa ration tank entry. 21. Flotation device according to claim 20, characterized records that the radial outlet means a horizon tales baffle plate to the Sus flowing against it to redirect pension in the radial direction. 22. Flotation device according to claim 20, characterized records that the radial outlet device several dis Crete radially directed outlet opening distributed around the circumference includes. 23. Flotation device according to claim 1, characterized records that above the separation tank Removal unit provided for the high-fraction is a central with the main flow in the essential flush passage for the rich in fabrics Fraction and includes at least one funding institution, to a reject outlet around the substance-rich fraction respectively. 24. Flotation device according to claim 23, characterized records that the conveyor a rotating För the snail includes. 25. Flotation device according to claim 23, characterized records that the conveyor at least one in rotate essentially horizontal channel with the clearing paddles.   26. Flotation device according to one of the previous An sayings, characterized in that the flotation print zip is not selective. 27. Flotation device according to claim 26, characterized ge indicates that the flotation principle as a pressure release flotation is carried out and in the Suspen area sions inlet an inlet for a gas bubble Liquid is provided. 28. Flotation device according to one of the previous An sayings, characterized in that the flota tion principle is selective. 29. Flotation device according to claim 28, characterized ge indicates that in the area of the suspension inlet Inlet for chemical additives is provided.