ES2214203T3 - DEVICE FOR FLOATING IN COLUMN. - 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 degrees to the horizontal, and preferably 20-30 degrees . 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

Device for column flotation.

The present invention relates to a device of flotation for the separation of materials or mixtures of suspension materials for the formation of at least one rich fraction and a material poor fraction provided with a column-shaped separator tank, composed at the bottom of a suspension inlet as well as several plates overlays arranged diagonally, a first exit for the fraction poor in materials and also in the upper zone, arranged a second exit for the fraction rich in materials.

Such a flotation device is known for the publication "Wochenblatt für Papierfabrikation", 1998, number 13, page 660. Such provision has, against the provisions usual flotation with suspension flows primarily horizontal, the advantage of a considerable lower requirement of surface for installation while height considerably higher required for it, in general, is not review. With this arrangement a suspension flows up to along the outer walls of a cylindrical container, with that clarified water enters radially inside a pipe central collector between multiple separation cones distanced and can be evacuated. A disadvantage of this known arrangement is, however, that the water flow clarified, by virtue of the direction of the inward flow, It has an increasing flow rate, so the particles that flow up and that must be separated have the tendency to be dragged. This decreases the degree of efficiency of material separation. Another disadvantage is in which successive processes of separation, whether processes of flotation or the combination of flotation and filtration processes, require the installation of separate construction groups that subsequently they must be connected to each other.

Other devices for column flotation are known from US 5467876 and US 5294003.

Based on this, the invention aims at create a flotation device of this type that avoids drawbacks mentioned above and stands out especially for a effective separation of the desired suspension materials in a fraction poor in materials and a fraction rich in materials. In addition, the arrangement must also allow serial connection Compact and functional multi-stage separation.

This object is solved by features mentioned in patent claim 1. Other Advantageous variants result from the subclaims.

The essential advantages of the invention consist in that, by the arrangement of the vertical flow radially towards above and the radial arrangement of the sheets outside the flow main, the flow of the material poor fraction is directed radially outward and, for this reason, increasingly slow producing a better separation of the particles. Another advantage is that the material-poor fraction is collected in the outer perimeter, that is, behind the edges of flow sheets below, which, with a reduced space requirement, can provide for other stages of separation, either as other stages of flotation or other filtration. Through a cascade sequence appropriate multi-stage separation, especially stages of flotation by different principles, (selection procedures physical and by pressure attenuation) can be obtained multiple fractions of different contents of materials. The requirement of additional space in radial direction that with this originates, is relatively small

In the most convenient way, the separator tank It has a circular cross section. If necessary also other forms of sections are possible, especially a section polygonal cross section, especially a cross section triangular or square.

Normally the separator tank is configured cylindrical. In the case that for technical reasons it is a great accumulation of the fraction rich in materials in the upper zone, a conformation of the main flow channel may be advisable funnel or conical, that is, a radial position towards behind the leading edges of the plates located more above.

According to an advantageous variant of the invention, find at least one other radially outside the collecting channel arrangement of several second overlapping sheets, arranged in cascade shape, with which the collecting channel is formed by the downstream edges of the first mentioned sheets and the edges flow up the second sheets. This arrangement allows a better separation and especially the evacuation of a first partial fraction after the first flotation step and the evacuation of the remaining fraction after the second step of floatation.

For this purpose, they are preferably provided in the lower end of the collecting channel inlet openings for the introduction of chemicals and / or fluid mixtures bubbling to apply a selective principle (especially by collector adsorption or hydrofugation) and / or a principle not Selective flotation principle.

According to another variant of the invention, alternative or additionally, a space outside the collecting channel is provided of filtrate filled with filtrate particles fed by it. In this way, a separation of materials is possible according to the filtration principle, which only has a requirement of additional radial space greatly reduced. With this, you get a particularly effective filtration when provided a filter outlet and a filter material outlet, where the filtering particles traverse the filtering space in countercurrent to the flow of the filtrate, thereby eliminating for regeneration and fed again in regenerated state on the opposite end.

In all the above described embodiments, they can advantageously provided separate outputs for the elimination of different fractions between the flotation stages and / or of individual filtration

According to another advantageous embodiment of the invention The sheets are shaped like closed conical rings. A especially good separation of the fractions is obtained when the blades have an angle of inclination with the horizontal of 10º - 40º, preferably 20º to 30º. It is also advantageous that the length of the sheets in the direction of the flow of the poor fraction in materials it is 1 to 4 times larger than the width of the main channel of limited flow through the inner edges of the sheets. With this can increase the distance between the bottom up adjacent sheets in order to respect the different conditions of flow and consistency in the lower or upper zone of the separator tank

With this, they can properly conform to less a part of the wavy sheets so that the undulations run in the perimeter direction so that, with this, no reduction in the flow of the poor fraction is related in materials. This development has the advantage of considerable greater stiffness of the sheets.

A particularly advantageous improvement of the invention provides that at least a part of the sheets are formed as a multilayer structure, preferably honeycombs, with two outer layers and joining structures intermediate, so that channels are preferably found through flow between the outer layers. This way you get a substantially greater resistance of the sheets.

Another variant of the invention provides that the suspension inlet comprises a feed pipe linked with a radial output device for the formation of an escape in radial direction and this one is covered with a dome, preferably conical, with a central passage, so that the suspension enters the separator tank through the center through that He passed. In this way a favorable discharge of the suspension is achieved to the lower zone of the separator tank.

Next, the invention is described more. in detail on the basis of the attached drawings, in which show

Figure 1, a schematic view, in section longitudinal, of a first embodiment of the invention with a flotation stage and a filtration stage;

Figure 2, a schematic view, in section longitudinal, of a second embodiment of the invention with two consecutive flotation stages;

Figure 3, schematically two ways blade alternatives, and

Figure 4 schematically an arrangement with three consecutive flotation steps.

In figure 1 it is shown schematically, in a axial longitudinal section, a first embodiment of the invention, therefore of a flotation device 10a. This one understands as constructive group essentially an influx unit 12, a material separation unit 14, a discharge unit 16 for the material rich fraction and a first collecting zone 18 for the material poor fraction. In addition, a second collecting zone 20 for solid particles.

The inflow unit 12 has a pipe of feed 22 for the suspension to be separated which, in the embodiment shown leads to several separate outputs 24 or a ring-shaped outlet, provided with baffle plates 26. In feed pipe 22 or in the area of exits 24 preferably a feed pipe is provided, not shown, for a liquid mixed with gas bubbles for a non-selective flotation and / or chemicals for a flotation selective

The separation unit 14 is located consisting essentially of a cylindrical separator tank 28 in whose central area forms a vertical main flow channel 30 running from the inflow unit 12 to the unit of discharge 16. In there, radially outside the channel of main flow 30, an amount of axially separated sheets 32, conically shaped in the form of ring, between which a flow is defined, radially outward and diagonally down, from the material poor fraction towards the first collecting zone 18. This first collecting zone 18 in ring shape, formed between the wall of the separator tank 28 and the edges flow down the sheets 32, leads to a collecting sector 34 for the first material-poor fraction, located above the upper sheet 32 in which a first pipe is provided collector 36 for this first fraction poor in materials.

To a simple monopathic realization of the invention the construction groups described would suffice so far, where the first collecting pipe 36 in one such Simple execution should not necessarily be provided above but, also elsewhere, for example, below.

The embodiment presented in Figure 1 It includes, in addition to the floating stage so far discussed, a filtration stage that will be described below.

Radially outside, concentric to the wall of the separator tank 28, a wall is provided at a distance outer filter 38, so that a space is formed between the two of filtrate 40, essentially cylindrical. Filtering space it is filled with a filtering material, preferably sand of certain consistency or other filtering materials such as coal activated or mixtures thereof.

This filter space 40 comprises at its end upper a second collecting pipe 40 for a second fraction poor in materials that is obtained after a stage of flotation and a consecutive filtration stage. Above filtering space 40 is a regeneration unit of filter material 44, not particularly detailed, which has as object to purify or regenerate the filter material and bring the filter material regenerated to filter space 40. The material filter goes through filter space 40 and reaches a channel of evacuation 46, from where in the consumed state returns again, to through pipe 48 only sketched, to the regenerating unit of filter material 44. The filter material regenerator unit 44 comprises at least one discharge pipe 47 for a second fraction rich in material produced by the regeneration of the material filter that is in the filter space 40 because of the material separation.

The filtering space 40 is communicated with the first collecting zone 18 by one or more openings of communication 50, through which the fraction enters the zone of filtering having already crossed the flotation zone and not having It was discharged through the first collection pipe 36.

The discharge unit 16 consists of the essential of a collecting channel 52, which is widening, for the fraction rich in materials and that leads to one or more gutters or pipes collectors 54. To better transport the fraction rich in materials, usually sludge, from the collector channel 52 to the collecting channel 54, one or more are provided transport devices 56, represented as provisions of rotating vanes.

Under the material separator unit 14, preferably functionally linked with the inflow unit 12, a collector device 58 for sedimentation of heavy particles leading to a sediment discharge 60

The method continues to be described of work of this first embodiment of the invention.

A feed pipe 22 flows through suspension, to which chemicals and / or chemicals may be added gas bubbles, towards exits 24 and is diverted by the plates baffles 26 such that, upon entering the inflow unit 12, there is first a horizontal flow that, upon entering the main flow channel 30, is transformed into a radial flow principal. This process is supported by the conical shape of the sheet bottom 32. The type of generation and the place of influx of gas bubbles or the amount and size of the bubbles thus determine the type of flotation (flotation by attenuation of pressure or by dispersion).

The desired suspension materials are separate on their way up, under the action of bubbles of gas and / or aggregate chemicals, in a fraction rich in materials that continues to flow up and in a poor fraction in materials that cross the sheets 32 radially. The material rich fraction, usually muddy, can be diverted, after collection, to the discharge unit 16 by means of transport devices 56. This fraction rich in materials may contain unwanted materials, such as ashes or ink particles from the treatment of recycled papers (usually called a rejection fraction) or well valuable materials, such as those from the mineral exploitation

The poorest fraction in minerals, diverted radially out of the main flow in the main flow channel 30, reaches the first collecting zone 18 after crossing the annular spaces formed between sheets 32. While, at contrary to that shown in figure 1 of the first embodiment, no another filtration process occurs consecutively, this is the desired material-poor fraction that is eliminated through the first collection pipe 36.

However, if a separation is desired most effective of at least a part of the fraction found in the first collecting zone 18, this partial fraction flows going through the communication openings 50 in the space of filtered 40 and, from there, in the vertical direction upwards, in counterflow of the flow of filter material that runs from from top to bottom. From the second collecting pipe 42 you can extract a second fraction poor in materials from which, contrary to the deviable fraction through the first pipe manifold 36, filtered materials are removed which in turn are removed from the system by means of the discharge pipe 47. With the filter material circulates between the filter space 40 and the filter material regenerator unit 44. The particles weights obtained during separation, for example, particles of iron, fall to the sediment collector 58 and a continuation to sediment discharge 60.

Figure 2 shows a form of alternative embodiment of the invention in the form of a device of flotation 10b which differs from the embodiment according to the figure 1 in which two flotation stages are arranged in shape consecutive. Same references designate the same pieces constructive To avoid repetition, refer to the description mentioned above, as soon as she refers to a first step of floatation.

The embodiment of Figure 2 differs from the Figure 1 in which radially outside the first collecting zone 18, a second group of sheets 62 and, radially, a third zone is planned outside collector 64. Even when in the sketched realization the first sheets 32 and the second sheets 62 have the same separations and inclinations, this is not necessary. Rather, the quantity, shape, inclination, etc. of the second sheets 62 can be independently selected from those of the first sheets 32 depending on the specific conditions.

At the lower end of the first zone ring collector 18, in this embodiment a pipe is provided of feed 66 whereby a liquid mixed with gas bubbles or chemicals to get certain flotation conditions in the first collecting zone 18.

Above the third collecting zone 64 is a third collection pipe 68 is arranged to collect a second fraction poor in materials that, contrary to the removable fraction through the first collecting pipe 36, is free of other materials to be separated.

Provided that in this context they refer to the collector pipes 36, 42, 68, any form must be understood collecting device Especially it can be several pipes or openings provided in the walls and that only outside of the walls flow into collecting pipes.

In figures 3a and 3b two forms of sheets 32, 62 that are suitable instead of simple shapes flat. Figure 3a shows a honeycomb structure with two outer surfaces 70a and 70b, among which are provided union reinforcements 72, where the gray areas represent shadows. Preferably, the gaps formed between the joining reinforcements 72 they constitute passages through which you can also take part of the flow. In figure 3b you will find represented a corrugated embodiment of the sheets 32, 62 where the flow direction is indicated by an arrow, that is, run parallel to the front of the ripple.

In figure 4 it is shown schematically a provision of three consecutive flotation stages that are would look similar to the embodiment shown in figure 2, only that radially outside the third collecting zone 64 there would be other sheets. The central axis not shown in figures 1 and 2 shows that here one side is not shown completely. Out of the third collecting zone 64 is provided in this embodiment other plates 74 of another flotation stage, which preferably have another separation of the adjacent sheets. Radially outside plates 74 is found, only schematically sketched, a fourth collecting zone 76 for an even poorer fraction in materials.

Claims (32)

1. Flotation device (10a, 10b) for the separation of materials or mixtures of suspension materials for the formation of at least a material-rich fraction and a material-poor fraction with a column-shaped separator tank (28), composed in the lower area of a suspension inlet (12) and several superimposed sheets, arranged diagonally (32), a first outlet (36) for the material-poor fraction and, in the upper part, a second outlet ( 52) for the material rich fraction, characterized in that the suspension inlet produces a central vertical main flow, whereby the sheets are arranged radially outside the main flow and produce an outward and diagonal flow for the material poor fraction downwards and radially formed outside the sheets an annular collecting channel (18) for the material-poor fraction. 2. Flotation device according to claim 1, characterized in that the separator tank has a circular or polygonal cross-section. 3. Flotation device according to claim 1, characterized in that the separating tank is shaped funnel with a section that widens upwards. 4. Flotation device according to one of the preceding claims, characterized in that at least one other arrangement of several second sheets (62) superimposed cascading is arranged radially outside the collecting channel, whereby the collecting channel is formed between the downstream edges of the first mentioned sheets and the upstream edges of the second sheets. 5. Flotation device according to claim 4, characterized in that feed openings (66) for the introduction of chemical products and / or mixtures of fluid with gas bubbles are provided at the lower end of the collecting channel. 6. Flotation device according to one of the preceding claims, characterized in that a filtering space (40) filled with filtered particles provided therein is provided radially outside the collecting channel. 7. Flotation device according to claim 6, characterized in that a filtering outlet (42) and an outlet of filtering material (46) are provided, whereby the filtering particles pass through the filtering space in flow contrary to the flow of the filtered, being separable for regeneration and entered again in a regenerated state by the opposite end. 8. Flotation device according to one or more of claims 4 to 7, characterized in that several arrangements of flotation sheets according to one of claims 1 to 3 and / or filtering arrangements according to claim 6 are arranged concentrically Regarding the others. 9. Flotation device according to claim 8, characterized in that separate outputs for the discharge of different fractions are provided between the individual flotation and / or filtration stages. 10. Flotation device according to claim 8, characterized in that two or three arrangements of flotation sheets are arranged in a concentric cuvette shape with respect to each other. 11. Flotation device according to claim 8, characterized in that two or three filtering arrangements are provided radially outside an arrangement of flotation sheets. 12. Flotation device according to one of the preceding claims, characterized in that the sheets have the shape of closed conical rings. 13. Flotation device according to one of the preceding claims, characterized in that the blades have an angle of inclination with respect to the horizontal of 10 ° - 40 °. 14. Flotation device according to one of the preceding claims, characterized in that the blades have an inclination angle with respect to the horizontal of 20 ° - 30 °. 15. Flotation device according to one of the preceding claims, characterized in that the length of the sheets in the direction of the flow of the material-poor fraction is 1 to 4 times greater than the width of the main flow channel limited by the inner edges of the sheets. 16. Flotation device according to one of the preceding claims, characterized in that the distance between adjacent sheets increases from the bottom up. 17. Flotation device according to one of the preceding claims, characterized in that at least a part of the sheets are shaped in a corrugated manner. 18. Flotation device according to one of the preceding claims, characterized in that at least a part of the sheets is formed as a multilayer structure with two outer layers (70a, 70b) and joining structures (72) between them. 19. Flotation device according to claim 18, characterized in that at least a part of the sheets is formed as a honeycomb structure. 20. Flotation device according to claim 18, characterized in that through-flow channels are formed between the outer layers. 21. Flotation device according to one of the preceding claims, characterized in that at least a part of the sheets are shaped as microporous membranes. 22. Flotation device according to one of the preceding claims, characterized in that at least a part of the sheets are pumped. 23. Flotation device according to claim 1, characterized in that the suspension inlet comprises a feed pipe (22) connected with a radial outlet device (24, 26) for the formation of an exhaust in the radial direction and with which The radial exit device is covered with a dome with a central passage, so that the suspension enters the separator tank through the center through that passage. 24. Flotation device according to claim 23, characterized in that the radial output device comprises a shock plate for deflecting the incident suspension in the radial direction. 25. Flotation device according to claim 23, characterized in that the radial outlet device comprises several discrete outlet openings (24) distributed over the perimeter. 26. Flotation device according to claim 1, characterized in that a discharge unit (16) for the material-rich fraction comprising a passage (52), essentially aligned with a central main flow for the fraction, is provided above the separator tank. rich in materials, and at least one transport device to bring the fraction rich in materials to a rejection outlet. 27. Flotation device according to claim 26, characterized in that the transport device comprises a rotating auger screw. 28. Flotation device according to claim 26, characterized in that the transport device essentially comprises a horizontal channel (54) with rotating friction vanes (56). 29. Flotation device according to one of the preceding claims, characterized in that it is prepared for non-selective flotation. 30. Flotation device according to claim 29, characterized in that the flotation is carried out as a pressure attenuation flotation and provides an inlet for a liquid mixed with gas bubbles in the suspension inlet zone. 31. Flotation device according to one of the preceding claims, characterized in that it is prepared for selective flotation. 32. Flotation device according to claim 31, characterized in that an inlet for additive chemicals is provided in the suspension inlet area.