US1549492A - Flotation apparatus - Google Patents

Description

Aug. 11, 1925.

i M. KRAUT FLOTATION APPARATUS Filed April 16, 1923 2 Sheets-Sheet 1 Y I By INVENTOR. Max ffraui;

ATTORNEY.

Aug. 11, 1925. 1,549,492

M. KRAUT' FLOTATION APPARATUS Filed April 16, 1923 2 Shoots-Shoat 2 I N V E NTOR.

BY v

ATTORNEY.

atentedl Aug. ll, 1925..

MAX. KRAUT, LOS ANGELES, CALIFORNIA.

FLOTATION APPARATUS.

Application filed April 16, 1923. Serial No. 632,369.

To aZZ whom it may concern:

Be it knownthat I, MAX KRAUT, a citizen of the United States, residing at Los Angeles, inthe county of Los Angeles and State of California, have invented new and useful Improvements in Flotation Apparatus. of which the following: is a specification.

This invention relates more specifically to a single compartment apparatus designed to be employed for the separation of mineral matter from the gangrue 0t ores, by the use of the well known flotation process.

A main object of my invention is to provide a flotation apparatus in which the introduction of air into the liquid pulp is accomplished by forcibly expanding the volume of the liquid pulp.

A further object of my invention is to provide a simple and eiiicient means for finely and evenly distributing the oils or other reagents to the liquid mineralized pulp during operation of the apparatus.

Another object of the invention is to pro vide a flotation apparatus that will combine highest etiiciency in operation with the lowest power consumption.

A still Further object oi my invention is to provide an apparatus that will occupy small floor space, which is simple in-construction, and economical in operation.

I accomplish the above objects by means of the apparatus herein described and illustrated in the accompanying drawings, in which:

Fig. 1 is a central longitudinal section through the flotation apparatus.

Fig. 2 is a sectional plan view of the same taken on the line 2-2 of Fig. 1.

3 is a cross section oi the apparatus talzen on the line 33 of Fig. 1.

Fig. 4 is a sectional plan view of the, pulp deflecting ring.

Fig. 5 is a cross section of the pulp defleeting ring taken on the line 5-5 of Fig. 4-.

Fig. 6 is a partial side elevation of another form of the pulp rotor member.

Fig. 7 is a partial enlarged detail cross section of the upper portion of the pulp rotating element.

The preferred form of construction, as illustrated in the drawings, comprises a substantially rectangular combined aeration and frothing chamber 10. consisting of upper side and end wall sections 11. 12, 13 and 14, the lower portions 15, 16, 17 and 18 of the sections inclining towards the center of the chamber 10, and a bottom wall 19, mounted upon a suitable supporting frame work. Communicating with the bottom of the chamber is an inlet pipe 20 through which the pulp to be treated is introduced into the apparatus, the pipe 20 passing through the inclined portion 15 of wall section 11 and communicating with a port 22 formed in the lower end of a vertically 6 disposed truncated conical shell or casing 23, bolted or otherwise secured to the bottom wall 19 of the aeration and frothing chamber. The upper portion of casing 23 terminates adjacent the upper edges of side walls 7 13 and 14 of chamber 10, and is provided with a hollow cap or hood 24 open at its upper cud 25 to atmosphere.

Disposed in casing 23 and rigidly secured to the lower portion of a vertically disposed shaft 26 is a hollow truncated cone 27. similar in conti'miration to the casing; 23. Cone 27 is provided at its lower'end with a sleeve 28 to which the shaft 26 is rigidly secured. and at its upper end it is provided with a 3 wall 29 havinsr a centrally disposed sleeve 30 through which the shaft 26 passes. The upper end of shaft 26 passes through a hearing 31. secured to a cross beam 32 of the supporting frame work. and on the upper end is secured a bevel drive wheel 33, which engages a frictional driving pinion 34 rigidly secured the power drive shaft 35. power bcin o' supplied thereto through the medium of pulley 36 belted to a source of power (not shown).

The peripheral'wall of rotating: cone 27 is provided with. a plurality of perforations 40 to permit air and atomized oil to be drawn therethrouerh to the space formed between shell 23 and rotor 27 during the operation of the apparatus. The upper wall 29 of the cone is provided with a circular groove 41 having inclined side walls, and in the bottom of this groove are a series of apertures 4-2.. preferably four in number, through which pass downwardly extending tubes 43, into the interio-r of the rotor, terminating approximate- 1y at the central portion thereof. Flotation oil or other suitable reagents are admitted to groove 41 through a distributing-pipe 44 secured to beam 32 of the frame work of the apparatus. the oil or other reagent being fed to the supply pipe in anypreferred manner.

Secured adjacent the upper end of casing unit, but preferably they are arranged in series as shown, such an arrangement proving more efficient in the retreatment of the mineralized pulp. The upper end wall section 12 which separates chamber 10 from the chamber of the adjacent apparatus, when arranged in series, is provided with a pulp overflow opening 53 controlled by a gate valve 54 of usual construction operated by a valve lifting mechanism 55 secured to the upper edge of the wall section. Secured on either face of wall section 12 and directly over the overflow opening 53, are pocket or bafile constructions 56 and 57, open at their lower ends, the open end of pocket57 being connected to a downwardly extending pulp directing pipe 58 which leads to the lower end of easing shell 59 of the apparatus mounted in the adjacent flotation chamber. By means of the pocket or battle constructions 56 and. 57, the froth carrying the metallic values will overflow the edges of the side walls 13 and 14 of the apparatus, while the partially treated pulp passes as heretofore noted, through the port 53 connecting the two chambers or compartments of the apparatus, for retreatment. A by pass discharge pipe 60 passes through the lower portion 17 of the wall section 12 through the inclined section 61 of the adjacent chamber, the discharge end terminating and communicating with the lower end of the pulp directing pipe 58 that is secured to the inclined wall of the adjacent chamber. Inclined wall 62 is provided adjacent the bottom thereof with a by pass tailing discharge pipe 63, the discharge end passing through a vertically disposed partition wall 64, into av narrow compartment 65 at the end of the apparatus formed by the wall or partition 64 and wall 66. The upper edge of wall 66 constitutes a pulp tailing overflow and is controlled bya gate valve 67 similar in configuration to the gate valve 54 mounted on the partition dividing the flotation chambers. At the bottom of wall 66 is a sand or tailing discharge opening 68 controlled by a valve 69, the coarse sand or tailings constantly flowingthrough said opening and through a port 70 formed at the lower end of the end wall 71 of the apparatus when the same is in operation.

In order to increase and accelerate the pulp lifting power of the hollow rotating conical aeration chamber 27 a series of helical grooves 75 may be formed in its peripheral surface, as clearly shown in Fig. 6 of the drawings, the grooves materially assisting the upward movement of the pulp during the operation of the apparatus.

The operation of the apparatus will be understood from the following description.

Power is applied through the medium of shaft 35, to the lower end of which is rigidly secured the hollow truncated cone rotor 27. Pulp is then introduced through inlet feed pipe 20 to the interior of the hollow casing 23, the revolving rotor causing the pulp to move upwardly in a helical path in the space between the outer and inner surfaces of the rotor and casing, until it reaches the pulp discharge deflecting ring. The curved blades of the deflecting ring 50 break up the velocity of the oiled pulp and cause it to spread out radially in a thin even layer on the surface of the pulp level in the chamber 10. It will be understood that while the apparatus is in operation, the chamber is always maintained in a full condition, the pulp level being kept approximately at the upper edge of the deflector ring.

During the upward motion of the whirling pulp, air and oil are introduced into the interior of the hollow rotor 27 through the downwardly extending feed pipes 43, air entering through inlet 25 formed in the upper portion of the cap or hood 24, while oil is delivered from distributing pipe 44 suspended from the frame of the apparatus.

The centrifugal force geherated by the re-- volving rotor spreads the oil or other reagents into a thin layer. There is a tendency to create a partial vacuum in the space between the rotor and its enclosing casing or shell. and consequently also in the interior of the hollow rotor which is in communication with the space between the casing and rotor through the perforations 40. It will thus be seen that air will be drawn in through the pipes 43, absorbing in its travel the oil or other liquid reagent, which step is essentially an atomizing process, the atomized air and oil being drawn into the whirling mass of pulp where it becomes thoroughly mixed. The aerated and oiled pulp when discharged through the deflecting ring 50, spreads itself in a thin layer on the surface of the liquid pulp forming bubbles which accummulate in a mass of froth carrying the metallic sulphides and overflowing the edges of the side walls 13 and 14 of the apparatus.

The circulation of the liquid pulp through the apparatus is accomplished by means of the cone shaped rotor 27 for the following reasons. It will be observed that the diameter of the upper end of the rotor 27 is greater than at its lowermost end, and as a reaaeoa consequence, the velocity imparted to the circulating pulp will be greater at the upper end than at its lower end. Inasmuch as the internal pressure of a moving liquid decreases as its velocity increases, therefore the pressure at the lower end will be greater than at the upper end, causing the liquid pulp to rise in the space formed between the rotor and its casingin a helical path until it discharges through the deflecting ring into the pulp and frothing chamber of the apparatus.

When the pulp level in the chamber of the apparatus reaches a predetermined height it overflows into the adjacent tank of the series, the overflow being directly connected to the intake openings of the rotor of the adjacent section, as heretofore described. By this construction the pulp level of each chamber in the series may be independently regulated, thus allowing greater flexibility in the operation of the apparatus.

From the above description it will be observed that the apparatus will consume very little power for its operation as the power required varies directly as the square of the diameter, and is directly proportional .to the number of revolutionsof the rotor. As

the diameter of the rotor is comparatively small, it follows that it will only be necessary to employ a correspondingly low proportion of power, a rapid circulation and a thorough aeration being efl'ected with a minimum expenditure of energy. lBy forming helical rooves in the hollow rotating cone, the lifting power of the cone will be ma terially indreased; however, in practice the smooth surfaced cope has produced excellent results.

What I claim is 1. A flotation apparatus, comprising a chamber open at its upper end, a rotary pulp aerating element disposed therein, a casing mounted in said chamber and surroimding said element and spaced therefrom to form a passageway circular in cross sec-.

tion and uniformly increasing in diameter from its inlet toward its discharge end, means to deliver a liquid pulp to the passageway formed between said aerating element and casing at the lower end thereof, and power means to drive said aerating element.

2. A flotation apparatus comprising a chamber, a pair of concentrically disposed conical members vertically positioned there in with their adjacent wall surfaces lying in spaced relation, forming a pulp passage, apulp inlet leading to the lower end of the pulp passage, and means for rotating one of said conical members.

8. A flotation apparatus comprising a single aerating and frothing chamber, a ver tically disposed hollow-truncated cone for circulating the pulp, an enclosing conical shell surrounding said cone and with its inner wall parallel spaced from the periphery thereof, said cone wall and shell wall affording a pulp passageway between the cone and shell, a pulp inlet leading to the lower end of the passageway between the cone and the shell, and means to rotate the cone.

4. A flotation apparatus comprising a chamber, a ,pair of concentrically disposed conical members vertically positioned therein with their adjacent wall surfaces lying in spaced relation, forming a pulp passage, a pulp inlet leading to the lower end of the pulp passage, and means for rotating the inner one of said conical members.

5. In a flotation apparatus, the combination of a single compartment pulp aerating and frothing chamber having a pulp inlet leading thereto, a vertically disposed perforated hollow truncated cone aerating element mounted in said chamber and means for rotating the same, a hollow conical casing of substantially the same form as said aerating element enclosing said aerating element and spaced apart therefrom to form a pulp passageway, the pulp inlet leading to the passageway at the bottom of said casing, whereby the liquid pulp will be caused to move upwardly in said passageway on a rotation of said aerating element, a pulp discharge and deflecting means mounted-in the upper portion oi: said enclosing casing, and neansfor introducing air and a reagent into the interior of said aerating element.

6. A flotation apparatus, comprising a single aerating and frothing chamber, a vertically disposed hollow perforated truncated cone for circulating and aerating the pulp, a conical enclosing shell surrounding said cone and spaced apart therefrom and having a pulp inlet at the bottom thereof leading to the space formed between said cone and enclosing shell, means to admit air and oil to the interior of said hollow cone, a pulp discharge opening tormed at the upper end or said enclosing shell, and means to rotate said cone. 7

7. In a flotation apparatus, the comblnallti tion of a single compartment pulp aerating nae same, a hollow conical casing enclosing the cone and spaced apart therefrom to form a pulp passageway, the pulp inlet leading to the passageway at the bottom or said casing, whereby the liquid pulp will be caused to move upwardly in said passageway on a rotation of said cone, a pulp discharge and deflecting means mounted in the upperpor- 1 tion of said casing, oil and air distributing means mounted on said hollow cone and communicating with its interior, and means to supply a liquid reagent to the interior of said cone.

8. A flotation apparatus comprising a chamber, a pair of concentrically disposed conical members vertically positioned there in with their adjacent wall surfaces lying in spaced relation forming a pulp passage, one of said adjacent surfaces being provided with a'pulp elevating projection arranged at an upward inclination, a pulp inlet lead ing to the lower end of the pulp passageway, and means for rotating one of said conical members.

In witness that I claim the foregoing I have hereunto subscribed my name this 30th day of March, 1923.

MAX mam".

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