US2182442A

US2182442A - Aerating machine

Info

Publication number: US2182442A
Application number: US174055A
Authority: US
Inventors: Lionel E Booth
Original assignee: Individual
Current assignee: Individual
Priority date: 1937-11-11
Filing date: 1937-11-11
Publication date: 1939-12-05
Anticipated expiration: 1956-12-05

Description

INVENTOR':

ATTORNEY new Bees, 1939 1 UNITED STATES PATENT orrics mama momma HonelE. Booth, Salt Lake city. Utah Application November 11, 1931, Serial No. 174,055 4 5 Claims. (01. 201-93) This invention relates to an improvement in aeration machines, and more particularly to an aeration or flotation machine oithe type forming the subject of my United States Patents Numbers 5 2,055,065 and 2,085,947, as well as oi an applica- ,tion for United States patent, Serial No. 114,114, Henry F. Dietz, applicant.

Aeration or flotation machines embodying the inventions of the aforesaid patents and appli m cation for patent, are peculiarly efilcient in producing an abundant, finely bubbled froth, which is much desired in the practice of modern flotation as applied-to metallurgical and other pulps.

20 cal shaft and is submerged at-a low point, in a 7 mass of pulp. Compressed fluid, such as air, is conducted into the space enclosed by the impeller,

and bubbles through the denture spaces. The

. initial bubbl'esare clipped into myriads of smaller I '25 bubbles by the teeth andare projected outwardly into and through the pulp body.

Patent 2,085,947 is concerned with peeling the l bubbles emerging from the impeller, and guiding theseupwaniiythrough the pulp in an orderly 3o manner, this being accomplished by means ot'a plurality oi'rhlades spaced around the impeller.

Application Serial Number 114,114 is concerned with spacing the peeler blades apart from the bottom of the tank or other container consti- 5 tuting the can or cells which confine the pulp, so

as toprovide circulation below the blades and thereby preventfthe pocketing of the pulp'anda consequent deposition of coarse sands on .the 'bottomofacell 1 'lhepresent is concerned with-theutilization to the fullest extent, of the advantages obtainable from the combined devices oi! the aforesaid patents, and for its principal obiects:

, 45 First. To conserve the finely bubbled, mineralbearing froth in the frothing compartment or zone, and to prevent its destruction and conse- 'quent dropping-'01. mineral values because oi. coming .into contact with the rotating impeller 50 shalt.

Second. Tocause the continuous, expeditious, and careful removal of the i'roth from the froth- :ing compartment or zoneby means of a stationary deflector, without the use of paddles or other f moving elements;

1 would be of comparatively'larse size. However,"'| $5 Third. To provide a simple, eflicient and inexpensive construction whereby the aforesaid objects are accomplished.

.-In the drawing, which illustrates an excellent embodiment of the invention: I

Fig. 1 is a plan of a flotation cell, partly in sec tion, taken on the line i-'-l in Fig. 2;

Fig. 2, avertical cross-section taken on the line 2-2 in Fig. 1; j

Fig. 3, a front elevation, partly in longitudinal, '10 vertical section, and drawn to'a reduced scale, of a battery of, for example, four flotation cells operatively connected one to another in'series.

Referring to the drawing, the numeral 20 designates a tank or container adapted to confine a '1 metallurgical flotation pulp in the form of a bubble column 2| having the pulp level It.

Submersedat a low point in the bubble column is an impeller 26 which is fast on a shaft 27, this shaft being rotatably supported in a bearing stand 28. The stand in turn is S pported on'longitudinal beams 29, and the beams may rest on end walls 30, and partition walls 3|, 3m, and lib, forming parts of the tank structure 20. Rte

shaft 21 may be provided with a pulley-(notl2 another and project from the basal rim-of the cone. A pipe 53, connected-with any suitable source 0! compressed air or othergfluid' (not indi- 85 bated) may extend upwardly into the interior of the impeller. I I

Spaced apart radially from the-basal circumterence of the impeller, and pace apart'circumter'entially'trom'one another, is a plurality oi 40 peler'blades 34,15 and It, the'bottom edges of which are spaced apart from the bottom 20a of tourcorners of the cell, where they rest removably on brackets a. I when compressed air is admitted through the vpipe I3, and the impeller is simultaneously retated at a suitable peripheral speed, for example,

1700 it. per minute, the airten'ds to bubble out through the spaces between the teeth or lugs 32. It the impeller were to standstill. the bubbles the properties of well known frothing reagents;

in rising through the pulp in the bubble column 2|, gather to themselves the mineral values in the pulp, and carry these values with them through and upwardly from, the pulp surface 24.

Since the mineral extraction from flotation pulp is fractional in a single cell, it is customary in practice to arrange the cells in batteries, the

showing in Fig. 3 being typical. Communication .through the successive. cells may be effected by means of openings in the respective partitions, similar to the one indicated at 4|. Pulp may be fed to a battery through a feed inlet compartment 42 at the first cell, and be discharged from a battery over a weir consisting of removable sections 43 at the last cell, the fiow of pulp being retarded by a baflle 45. By means of the removable weir sections, the pulp level 24 in all the cells, may be regulated as desired.

What-has been explained so far, is a brief rsum of the disclosures in the aforesaid patents and application for patent, and does not constitute part of the present invention, excepting .in combination or conjunction with what is now to be described. Y

The tank and its component cells, in cross-section, are preferably symmetrical on each side of the longitudinal axial plane of the impeller, and

are arranged to discharge froth along the two opposing longitudinal sides of the cells. Bridging 4 the frothing compartment of each cell longitudinally, is a trough 46 which may have the inclined 55 discharge mouth may contain removable weir sec- 35 The opening 52; should be only'large enough tosides46a, and the horizontal bottom 46'. The trough dips into the pulp so that the bottom of the trough is below the pulp level 24. The trough divides the frothing compartment into two parts 25a and 25b, and the trough sides form deflectors, which at least partially define the frothing compartments. Since the trough sides extend-upward and forward in converging relation to the wall lines 41 of the cell, each frothing compartment is given the form of an inverted wedge; the function of which will presently be explained. Opposite eachdeflector 46a is a. discharge mouth 5| through which the froth leaves the cell. Each tions 53, for the'purpose of varying, as may be required, the level at which the froth overflows. .The trough may be supported by any suitable means, for example, by clip angles 49 and 50,

go which are fastened 'to the opposing cross walls I level to which froth may rise, in order to prevent entry of froth into trough.

Inoperation, the abundance of fine bubbles produced by the impeller, riseth'rough the pulp, and emerge at the pulp level in a large volume of froth which brushes against the outside surfaces of the deflectors 46a and is positively and (5 continuously crowded ,or pushed throughthe discharge mouths. At the same time, the'trough prevents any portion of the froth from entering thereinto, and therefore, from coming into contact with the rotating shaft 21.

In past practice I have found that. without the trough, froth piles up around the shaft .21, and coming into close contact with the moving surface of the shaft, 9. large part of the individual bubbles of the froth are destroyed. Such destruction of bubbles," causes mineral particles with which they were loaded, to be instantly dropped,

and to be drawn down along the shaft into the lower part of the bubble column, where they must be picked up again by other bubbles. Obviously, such adverse action causes a veryv perceptible loss in efllciency, and cuts down the otherwise large.

capacity of the machine, correspondingly. The trough 46 not only prevents the objection just outlined, but at the same time, the stationary deflectors 46a, cause the froth from the frothing compartments 25a and 25b, to be automatically pushed, positively and vigorously, over the weirs 53 instead of sluggishly building up in the space pulps, for the reason, that it finds an extensive application in this art. However, it is not necessarily restricted thereto, because the bridgingv trough with its upwardly diverging, deflecting side members, may be usefully employed inother arts where the aeration of a liquid or semi-liquid is involved in order to produce a froth which rises through the mirror surface of the liquid. So also, the term aeration is not restricted to ordinary air, but relates to any gaseous substance which is to be diffused through a liquid or semiliquid.

. WhatIclaimis:

1. An aerating machine, comprising means defining a bubble column, a hollow, rotatable impellerhaving teeth extending outwardly from the rim thereof and being submerged at a low point in the bubble column, means for supplying compressed air to the interior of the impeller, peeler blades disposed around the impeller and spaced apart from one another and from the impeller, said peeler blades being adapted to guide upwardly; bubbles discharged by the impeller, and a trough bridging the upper part of the bubble column, the said trough including a lower portion dipping below the level surface of the pulp in the bubble column and sides inclined upwardly and outwardly from the said lower portion for the. purpose of deflecting outwardly froth from the bubble column.

2. A flotation machine, including in combina tion, a cell structure enclosing a. bubble column, a hollow rotatable impeller having teeth extend ing from the rim thereof, the said impeller being disposed at a low point in the bubble column,

means for supplying compressed air to the line peller, peeler blades disposed around the impeller and spaced apart from one another and from the impeller, the said peeler blades being disposed to guide upwardly, ,bubbles discharged by the impeller, means defining a discharge mouth in proximity to the top of the bubble column, and a deflector defining at least partially, an inverted 0 adapted to guide wedge-shaped frothing compartment'immediatelv adjacent the said discharge mouth.

3. A flotation machine in accordance with claim 1, wherein a definite level surface oi pulp is maintained in the bubble column and the said deflector dips below the pulp level surface.

4. A fiotation machine, comprisinga container having longitudinal walls and cross walls joined to the longitudinal walls and disposed to form a cell for confining a bubble column of 9 119. a hollow rotatable impeller having teeth extending from the rim thereof and being submerged at a low point in the bubble column, adriving shaft extending upward from the impeller, means for PP impeller, peler blades disposed around and spaced radially apart from the impeller, the said peeler blades having their lower edges spaced apart from the bottom surface of the container and being upwardly, bubbles discharged by the impeller and the -driving shaft and compressed air-to the-interior of the at-the same time, to permit circulation of peeler blades and the bottom of the containena trough bridgi umn from cross wall to cross wall, the said trough consisting of a lower portion closely surronnding deflecting side portions extending upwardly 'and outwardly from said least partially define a frothing compartment immediately above the pulp surface level,

lower'portion' in order at Y and means defining froth discharge openings in the said discharge openings being in cooperative proximity to the respective deflecting side portions of the saidtrougb.

5. A flotation machine as recited in claim 3,-in

wbichthe cell structure, the deflecting troughand the frothingcompartment are each andall, symmetrical on both sides of the longitudinal axial plane of the impeller and its driving shaft.

1.10mi; E...

the said longitudinal wens,

pulp in the space between the the upper part of the'bubble col-