DE2055951C3 - Stirrers for flotation cells - Google Patents

Description

60

The invention relates to stirrers for flotation cells with a stirrer plate and an air supply through the stirrer shaft in the stirrer plate.
Such a stirrer used as a vibrating stirrer is included in the German Auslegeschrift I 188 012. The stirring plate has, in order to produce a downwardly encircling, conical, deeply shaped openings with openings in the tips. as they are also known from the German Palentschrift 413 643 for sieve bottom for pneumatic flotation apparatus.

The known vibratory agitators require a high energy requirement, but do not sufficiently ensure the swirling of the pulp, in particular not the ascent of coarse-grained parts. They do not cause good air dispersion. un stingy. the air cells are demineralized. what is due to it. that there are only so few openings that they make up a total of only Ϊ0 to 12 ⁰ O of the surface of the stirring plate ... With this small number of conical openings, the circulating currents pulsing through them are so small that none in the lower area can also be used to discharge coarse-grained particles sufficient speed of the ascending flow is achieved.

In order to also achieve the speed required for removing coarse-grained particles, the stirrers were given a higher oscillation speed. However, this caused accelerated wear on the stirrer, an increase in the specific energy requirement (per 1 m ^{: 1} cell) and the formation of low-frequency vibrations in the quiet zone of the flotation cell, which shook the mineral particles from the air bubbles.

In addition, a sufficiently high dispersion of the air bubbles is not achieved, namely because because the linear velocity of the air stream flowing out of the openings of the air supplying it P. ear is considerably greater than the speed of the circulating turbidity currents which flow through the Orifices of the stirring plate flow and eject the air.

The invention is based on the object of specifying a stirrer for flotation cells that is wear-resistant is and guarantees an increase in performance and a reduction in energy consumption.

The object is achieved in that the piston-like stirring plate has a horizontal air distribution pipe and has air lines branching off transversely from this, which run parallel to one another and between Openings for the passage of the sludge form on the upward stroke of the stirrer and with elastic ones Verseher valve flaps or lips for closing the lines on the downstroke of the stirrer are.

Such a design of the stirrer ensures the increase in performance and the decrease of electrical energy consumption, reducing de; Wear of the stirrer due to parts made of elastic Material, the increase in the turbulence intensity and the aeration of the slurry be low vibration speeds of the stirrer

It is advantageous that the parallel air ducts consist of downwardly open half-tubes to de Elastic flap split downward on the outer walls pen are attached.

When the stirrer goes down, the flaps open the openings for the turbidity to flow through. in the piston-shaped stirring plate and the openings in the half-tubular egg intended to flow out of air closed at the same time.

Such parts of the stirrer can be made by combining castings with rubber coating can easily be mass-produced.

Preferably, the parallel air ducts consist of downwardly open horseshoe profiles are used in de ren lower opening elastic profiles with valve lips and air outlets.

Those with profiles made of elastic material before;. The parts of the stirring plate shown are also in small series production easy to manufacture and according to your ·. Easy to replace wear and tear.

It is advantageous that the elastic profiles with Yentillipcn and at the inner inlet of the air outlet i » Mrömöffung are equipped with two further valve lips pointing downwards.

The air outflows ripple through the valve lips closed at the downward part of the stirrer, whereby the self-suction of air in i.-, the flotation ·· / hurry secured and the penetration of Turbidity in the interior of the piston-shaped stirring plate is prevented.

A preferred embodiment is that the parallel air lines consist of two facing " U-profiles are formed, in the upper slot an elastic profile with downward facing Valve lips, and in their lower slot an elastic cover strip acting as a check valve are used, which latter covers the air outlet openings on the lower legs of the U-Prolile.

In this way, the self-suction of air into the chamber of a deep hotation cell can be ensured as well as the reduction of the wear and tear of metal parts of the piston-shaped agitator plate thanks to the shielding effect of the outer cover strip.

It is advantageous that the parallel air ducts consist of two L-profiles, the overhead short legs facing each other, in which Slit an elastic profile with two outer lips pointing downwards at an angle and one in the middle Flap is inserted, which in turn also ends in two outwardly directed lips 4 = and so forms the closure for the air duct.

This design simplifies the design of the piston-shaped agitator plate because it replaces it of two insert profiles only one profile is used, the lips of the middle flap of the profile as Valves are effective.

Preferably there are between the parallel air ducts arranged vertical partitions.

This makes it possible to reduce the area of the openings in the piston-shaped stirring plate thanks to the: o increasing the distance between its parts and increasing the number of parts that make the piston-shaped Form stirring plates, reduce.

In the following the invention is illustrated by means of exemplary embodiments with reference to the drawings explained in more detail. It shows

1 shows a longitudinal section and partial section through a flotation cell,

2 shows a shaking stirrer with a partial section, FIG. 3 chic floor plan of the vibrating mixer,

F i g. 4 shows an enlarged section of the stirring plate of the vibrating stirrer according to FIG. 2,

5 shows a cross section of an insert profile with Vcnlillippcn, FIG. 6 a (Juerschnitl of an application profile with Valve lips, which are located at the inlet of the air outlet oil two has further valve lips.

Ed. 7 a section through a stirring plate, in which the parallel air ducts are formed from two U-shaped profiles, in which upper layer / an elastic profile with valve lips pointing downwards and in their lower layer /, an elastic pressure strip acting as a check valve is used.

F i g. S a cross section through a stirring plate. w.ihei the parallel ducts from two L-Pm ! ilen exist, the short upper limbs facing each other, in d.-ren Schiit / ein elastic profile with two outer lips pointing downwards and a miniature flap inserted is. which in turn also ends in two outwardly directed lips.

The flotation cell! (Fig. 1) has several. Departments on. namely a department! with a connection 3 for the pulp inlet, an abbey 4 with vibrating agitators 5>. for swimming conditioning the turbidity and a division '; with a slider? and a connector 8 for the outlets and one Slide 9 with a nozzle 10 for removing sand. There is also a department 11 with a Cap 12 provided for removing foam mass.

The cell 1 is equipped with a support frame 13 on which the vibratory drive 14 of the vibrating stirrer 5 is attached.

Each vibrating stirrer 5 has a conical shaft 15 (FIG. 2). through which he with a pipe adapter 16 (Fig. 1) and a threaded ring 17 of the support frame 13 is connected.

The vibrating stirrer S consists of one with reinforcing ribs 19 provided vertical tube 18, which has a horizontally arranged piston-shaped stirring plate 20 (F i g. 3), which consists of a. Air distribution tube 21 and half tubes 22 is formed. The air distribution pipe 21 is a horizontally lying tube, which with the cavity of the vertical tube 18 and with the Cavity of each half tube 22 (Fig. 2) is in communication. The half-tubes 22 (FIG. 4) are with their open sides facing downwards, lie parallel to each other and are equidistant from each other arranged, with openings 23 between them for the passage of turbidity during the upward movement of the Vibrating stirrer 5 remain.

The air distribution pipe 21 and the Ha'brohrc 22 are encompassed by a bounding box 24 (Fig. 3).

Air is supplied to the vibrating stirrer 5 (FIG. 1) by means of an air supply (not shown) supply system which is equipped with a valve 25, a Rota knife 2d and a manometer 27 In the lower part of the support frame 13 there is a longitudinal channel 28 which is used for Luftzuführunj in the vertical tubes 18 of the agitator 5 is determined. This is done by means of the intermediate pipe pieces 16, ii the cavity of which a throttle disc 29 is arranged with an opening 30, which is dependent on Location of the stirrer 5 in Department 4 of the flota tion cell 1 the supply of the required air amount secures.

Each vertical tube 18 (Fig. 2) of the vibrating stirrer: stands through an opening 31 with the air distribution tube 21 of the piston-shaped stirring plate 20 in connection. The air distribution pipe 21 is through an opening 32 connected to the half-tubes 22.

The Ilaibiohiv 22, which form the piston-shaped stirring plate 20 of the belt 1 of its 5, are on the forehead

ropes closed by a boundary frame 24 (Fig. 5) provided to be profiled in pairs sen, therefore, the half-insert pieces with air outflow openings 36 must be piped to allow air to flow out 22 a gap-shaped opening 33 (FIG. 4) are in advance. These inserts are seen in horseshoe, which are arranged through the longitudinal walls of the half-filaments, which form the piston-shaped stirring plate tubes 22 is limited. Along the walls are 5 20 form.

Flaps 34 attached from elastic material. In this version of the stirrer, the runs

Flaps 34 are split downwards in this way- Operation of the flotation cell similar to the above bc-

leads to the fact that they write 5 when the stirrer descends.

each other (open) and a closed one close When the agitator 5 descends

On the surface of the piston-shaped stirring plate 20, however, the valve lips 35 of the insert pieces do not

the. When the stirrer moves upwards, they go back to the air outflow openings 36, and consequently a part can

which together and open so at the same time both return to the air in the horseshoe profiles 37, and

the gap-shaped openings 33 on the half-tubes, the suspended particles can pass through the

22 as well as the openings 23 between the half-raw pulp flow enter the openings 36; also the

rcn 22, whereby the perforated flask-shaped agitator 15 Effectiveness of the dispersion of the air bubbles

plate 20 of the stirrer 5 is formed. can sink.

The operation of the flotation cell 1 is as follows: The advantage of these insert pieces is that

gender way. they are easy to make and easy to use

The pulp is under pressure through the nozzle 3 (they do not clog and are easy to replace). (Fig. 1) supplied to Department 2, it fills it up to 20 To improve the operation of the piston-shaped and flows into the swimming pool treatment department 4, valve lips can be provided on the agitator plate 20 on the agitator 5 in which it was subjected to the shaking action of the stirrer5 (Fig. 6) made of elastic material with two whitewashes will. The stirrers 5 are carried out by the vibrating parts valve lips 40, which at drove 14 set in vibrations, with a downward movement of the stirrer 5 the Luftausströmöffnun-Auf- and move down. 25 to 39 close.

Since the flaps 34 (FIG. 4) are in the form of a piston, all fears are dispensed with with this arrangement

gen agitator plate 20 (Fig. 2) of the agitator 5 from clasti- with respect to a clogging of the air outflow openings

When the material is poured, they are replaced by solid particles.

forward gear spread apart and close the This type of application gap iöidert the increase

Openings 23, a closed 30 hung of the air bloom dispersity is formed. This creates un-

Surface that supports the rising turbidity flow, the valve lips 38 an air cushion, which from underneath

flows around the piston-shaped stirring plate 20, generated. ten is pushed through the cloudiness. This gas

When the stirrer 5 goes up, the collapse liquid limit is a source of formation

pen together again and give the openings 23 a finely dispersed turbid-air mixture, which when

free, with the turbidity in descending currents 35 swinging of the stirrer 5 through the turbidity

Splits. which is ejected through the openings 23 between the halves,

pipes 22 flow through. To secure the air self-suction for deep

Thanks to the multiple vibrations of the agitator 5 flotation cells, the piston-shaped agitator plate

The slurry also takes place from coarse-grained 20 on the stirrer from parallel air lines from two

Sand particles from the bottom of the cell 1. At the same time 40 mutually facing profiles 41 be formed in

the from the column-shaped openings 33 of the upper slot an elastic profile with after

Half-pipes 22 escaping air from the flaps downwardly facing valve lips 42 and in their lower

34 broken into small vesicles and with the opened slit an elastic non-return valve

slurried solid particles of the processed material see cover strip 43 are used, which the air outlet

mixed. 45 openings 44 on the lower legs of the

In such a design of the piston-shaped U-profile 41 covers. The valve lips 42 uri the

Stirring plate 20 of the stirrer 5 is a high surface cover strip 43 are designed as insert pieces,

proportion of the openings on the surface of the agitator- In the lower slot of the U-profiles 41 are air vents

lers, from 60 to 80 ° / o. As a result, openings 44 are provided when going downhill

less 50 of the stirrer 5 is closed by the cover strips 43 for the vibrations of the stirrer 5

Energy than with the known stirrers are consumed.

and so at the same time such an ejection of the For the same purpose can occur the parallel air-air into the turbidity flows that the air under small pipes from which the piston-shaped stirring plate rem pressure to be fed to the turbidity. is composed, consist of two L-profiles 45,

Thanks to the intensive turbulence and the ventilation of the short legs above each other are turned on the circumference of the piston-shaped, an elastic profile 46 in the slot Stirring plates formed rising turbidity currents with two outer lip mites pointing downwards at an angle mineralized, finely dispersed, on the upper pen. the openings 23 (Fig.2) to the pulp surface emerging and foam-forming blow passages in the flask-shaped stirring plate 20 of the stir are saturated. 60 rers 5 close, and a middle flap 47 a

Which is set up during the swimming treatment of the sludge, which in turn is also split in two to the outside falling products are removed, namely the directed elastic lips that end when falling

Foam through the division 11 into the nozzle 12, downward movement of the stirrer 5 the closure for the air

the outflows through the slide 7 into the nozzle 8 form outflow openings 48,

and sand through the slide 9 into the nozzle 10. 65 On the piston-shaped stirring plate 20 of the stirrer 5

In another embodiment, the can between the air lines (half-tubes 22, piston-shaped stirring plate 20 on the RütteLriihrerS with horseshoe profiles 37, U-profiles 41, L-profiles 45)

valve lips 35 made of elastic material and designed along them as strips or rods.

led vertical partitions 49 (Fig. 8) arranged will. This can reduce the surface area of the openings on the surface of the piston-shaped Rührcllers 20 by increasing the distance between the Air lines (22, 37, 41, 45) and can be increased by reducing their number.

The valve lips and flaps can be designed with a thickening 50 (FIG. 8) at the ends will. This increases their strength in both the transverse and longitudinal directions.

The middle flap 47 (FIG. 8) can be a rigid one in order to stiffen it in the transverse and longitudinal directions Have reinforcement 51.

Experiments with the flotation cell with the Rüttclrührern according to the invention have shown that the The energy requirement is two to three times less than that of a flotation machine with a stirrer or a compressed air swimming machine with agitator.

The vibrating stirrers according to the invention lift larger ones in the flotation section of the cell Particles as the suction screws of the known agitator or compressed air swimming machines; the wear the stirrer turned out to be irrelevant.

In addition, the dispersing ability of the vibrating stirrer with respect to air is significantly higher than those with agitator or compressed air swimming machines.

With slurry and sand flotation, the flotation speed is higher than that with agitator or compressed air swimming machines.

The flotation cell with the vibrating stirrers of the invention can, thanks to the active washout the solid particles from the bottom of the cell easily even after a long period of non-use can be put into operation without difficulty, although compacted material deposited in the flotation cell Well there is.

1 sheet of drawings

Claims (7)

Patent claims: 1. Stirrer for flotation cells with a stirrer plate and an air supply through the stirrer shaft in the stirring plate, characterized in that that the piston-like stirring plate (20) has a horizontal air distribution pipe (21) and air lines (22. 37, 41, 45), which run parallel to one another and have openings (23) between them for Form the turbidity flow on the upstroke of the stirrer and with elastic valve flaps or lips (34, 35, 42, 46) for closing the lines during the downward stroke of the stirrer are. 2. Stirrer according to claim I. characterized in that Jie parallel air lines downwardly open half-tubes (22) exist, on the walls of which are split down elastic Flaps (34) are attached. 3. stirrer according to claim 1, characterized in that that the parallel air ducts consist of horseshoe profiles (37) that are open at the bottom, in your lower opening elastic profiles with valve lips (35) and air outflow openings (36) are used. 4. Stirrer according to claim 3, characterized in that the elastic profiles with valve lips (38) and on the inner Ein'itt of the air outlet flow opening (39) with two ^; further downward-pointing valve lips (40) are provided. 5. stirrer according to claim 1, characterized in that the parallel air lines two facing U-profiles (41) are formed, in the upper slot an elastic Profile with valve lips (42) pointing downwards, and one as a check valve in the lower slot acting elastic cover strip (43) are used, which latter the air outlet openings (44) on the lower legs of the U-profiles. 6. stirrer according to claim 1, characterized in that the parallel air lines two L-profiles (45) are made, the overhead short legs facing each other. in the slot an elastic profile (46) with two outer, obliquely downwardly pointing lips and a middle flap (47) is inserted. which the latter in turn also in two after ends facing outward lips and thus forms the closure for the air channel (48). 7. stirrer according to claim 1 to 6, characterized in that between the parallel air lines vertical partitions (49) are arranged.