US2191739A - Agitating, aerating, and/or mixing machine - Google Patents

Description

v; conjunction with v Patented Feb. 27, 1940 )UNITED SIP TENT o'rrlc a I "ao rarma aarirggkmro MIXING I James Joseph Bean,

to American Oyanamid 'Company, N. Y., a corporation of Maine Salt in. City, nah, assignor New York,

Application October 23, 193?,Serial s. 110,551

3 Claims.

This invention relates to an improved aerating; machine and particularly to improved aerating machines suitable for the froth flotation of m.in'

. erals.

Inthe pastmechanical aerating machines in which air is beaten into a liquid or pulp by mechanical means have gradually superseded the older and .less efficient types of machines particularly in the'iroth flotation of minerals. Most The high efliciency of the mechanical ma chines and particularly those of the Fagergren type has been-coupled witha certain lack of flexibility in changing from one ore to another. This has been a particular problem in the case of laboratory flotation machines and those which are used' in experimental or pilot plants or plants where the minerals to be floated are frequently changed. This lack of flexibility is due to the fact that the rotor and stator assembly-in the Fagergren type of. machine and similar elements in other mechanical machines using rotating agitators are rigidly mounted and in order to make 30 changes or small repairs on the element, it has been necessary to shut down the machine and I to disassemble the parts in question. In the case of some laboratory machine of the Fagergren type, a certain flexibility has been obtained by using a removable flotation chamber which can be lowered from contact with the agitating elements and cleaned out. However, it is still necessary to clean the agitating elements when changing from one mineral to another and this is a weakness and time-consuming element of the laboratory machines. It isalso desirable at times to change the aerating compartment and this could not be done without disturbing the agitating elements. g I The present invention provides for complete. elimination of diiilculties encountered in remov ing agitating elements and at the same time retains all oi the advantages oithe flrm and rigid stand, individual electric drive and the like, which 5o are notable characteristics of many of the most "'--.j: succ essiui mechanical machines including particularly? the Fagergren type of machine. The

invention'will be more particularly described in of the mechanical machines are provided with simia machine of the Fagergren A. type although its principle is applicabieto other machineshaving rotating agitators. Particularly, the invention provides for a linkage which permits withdrawing the agitating-element from the machine without, dismounting the machine and even, if desirable, without shutting it down. A simple tilting is usually not practical because the' clearance between the agitating element and the flotation chamber walls is normally insuflicient-to permit swinging the agitating element up in an arc.

According to the present invention the agitating elements are mounted on a suitable frame or housing which is provided with a linkage permitting it to be raised substantially vertically for a sufl'icient distance to clear the top walls of the i5 flotation chamber and then to 'tilt in an arc to completely expose the agitating elements. The invention'will be described in detail in conjunction with a-very simple type of linkage. It should. be noted, however, that the invention in its broader aspects is not limited to the particular design of linkage shown but any other linkage permitting the same mechanical movement may be substituted. The invention will be described in de-' tail in conjunction with a machine of the Fager- 'gren type, adapted for laboratory use. The details of the invention are, of course, equally applicable to larger machines. Itis an advantage that the operating characteristics of the machine are in no way altered by the inclusion of the improvement oi the present invention.

Inthe drawings,

Fig. 1 is a plan view of the machine;

Fig. 2 is a side view of the' machine in operating positiom' Fig. 3 is a side elevation. of the'machine with I the agitating-elements in a fully lifted position; Fig. 4 is'an enlarged detailed elevation of the linkage mechanismpartly broken away, showing the portion in section along the line 4-4 of Fig. 40 1; and a Fig. 5 is an enlarged vertical section through the flotation chamber and agitating mechanism, the section being taken along the line of '5-5 of Fig. 2. I K

The machine illustrated in the drawings, which is a laboratory type oi'Fagergren machine, consists'o! a frame I onwhich is mounted a table '2 which can be moved vertically on a slide through which its clamping bolts 8 extend. On the shelf 4 is'mounted the flotation chamber 5 having a froth overflowlip 8. An'agitamr housing 6 extends into the flotation chamber inthe operative position (shown.- in Fig. 2),. and carries in its lower end a stator formed of the staves I! which may, if necessary, be provided with a rubber covering. The housing also carries a pet-cock 2 2,

the opening of which can be adjusted to vary the amount of air beaten into the ore pulp during the operation of the machine- Inside the housing is a shaft I3 carrying the rotor staves l4 and being journaled in the large upper portion of the housing that contains the ball bearings I5. The top of the shaft is provided'with a pulley! which is driven from the motor; I0 by the belt II. The housing itself is integral with a hollow arm casting 9 on which the motor I9 is bolted. In this arm are pivoted two links l6 and I1, the latter being considerably longer than the former. The other end of the link I! is mountedonthe pin I8 in the framework I and the further end of the link I6 is keyed to a shaft I9 also journaledin the framework I (see Fig. 4). The shaft I9 can be rotated by its crank 20.

Inoperating position the arm 9 is horizontal,

resting on the top of the framework I. The pivot of the link I6 fits into a semi-circular groove 2| on the frame I. In this position the rotor and stator elements are near the bottom of the flotation chamber, the clearance being adjustable by a small vertical movement of the table 4. The operation of the machine is then the same as in a typical Fagergren machine in which the rotor and stator are rigidly and permanently mounted. When it is desired to change to another ore or for any reason to inspect or repair the agitating elements, the crank 20 is rotated in the direction shown by the arrow in Fig. 2. This causes the short link I6 to be rotated about the shaft I9 and raises the arm 9 substantially vertically because of the fact that the link I! does not permit the arm 9 to describe an arc during the first portion of the movement, the agitating element being moved substantially vertically until it can clear the top of the flotation chamber. At this point, which is determined by the relative length of the links I6 and H, the arm 9 begins to tilt and finally'assumes the position shown in Fig. 3 in which the agitating elements are entirely clear of the flotation chamber. V chine when it is desired to run another batch, the material adhering to the rotor and stator is washed out with a small stream of water, a tail- 'ings analysis made on the contents and the container either returned or replaced by another The crank is then rotated in the opposite direction to return the agitating elements into chamber 5.in they.

position shown in Fig. 2, at which time the motor may be. started and another batch run.

While the present invention is particularly imp'ortant in the laboratory machine where numerous batches of ores are run, it is also advantageous in larger machines for pilot plants or actual production. Of course, in such machines the designof the flotation chamber is suitably altered to provide for continuous inlet and discharge-of pulp and permit connection of the overflow lip to froth launders. The design in the case of the Fagergren machine is clearly shown in the Fagergren Patent No. 1,963,122 dated Junev 19, 1934, and it is an advantage of. the present invention that no serious change in the operation of the. machine is necessary. In other words, the present invention operates *with the same efliciency as a standard Fagergren machine and yet permits rapid removal of rotor and stator without requiring the machine to be taken I out of circuit. This is important in many produce tion installations where a relatively long string In a laboratory marotor and stator can be made without shutting 5 down the whole string.

Another important advantage is noted when operating with extremely thick pulps or with very coarse feed which may cause sanding. If the pulp is too thick for an. ordinary machine, it is not easy to start up the machine although the power available maybe sufflcient to keep it running once it is started. By means of the pres-' ent invention it is possible to raise the rotor and stator somewhat above the position on the bottom of the flotation compartment, which greatly decreases the starting torque required, to start the motor and gradually-lower the elements. This makes it possible to use a motor with a smaller overload capacity which means greater economy and in the case of coarse feed or sticking of the agitating mechanism, it is possible to rapidly lift the agitator and remove any obstruction.

The same possibility of moving the agitator while the motor is running is likewise of importance with a machine to be used for economical agitation of very viscous materials. It is possible to start the machine with the ag' ator partly raised and gradually lowerit into position.

Another important advantage of the present invention in production machines lies in the possibility of slight vertical movement of the agitating mechanism in order to-vary the clearance changing the design of the machine. Also variations of the ore feed in installations may require for best flotation emciency a varying degree of recirculation which can be taken care of by slight vertical displacement of the agitator column.

The laboratory machine shown in the draw-' ings is provided with a simple. hand crank for operating the linkage. Of course, in a larger machine the weight of the agitation mechanism is too great to permit the use of the simple hand crank and gearing is required in'order to move the linkage. A suitable reduction gearingcan, of course, be interposed between the'crank and the shaft I9. For laboratory machine use and in many cases for pilot plant use, a belt drive such as is shown in the drawings is advantageousas it permits varying speeds by changing the pulleys. However in large production machines it is often desirable to use a positive drive such as gear train, direct drive. or the like. The type of drive,

shown in the drawings.

In the case of pilot plant and production machines where it may be desiredto vary the clearance between the'agitating mechanism and the bottom of the flotation chamber, it is frequentlydesirable to associate a suitable scale and indicator with the shaft I9 so that the clearance can of course, is not limited to the particular form--' tained immediately. Such a scale, of course,'in

no way changes the operation of the invention. :7

It should be also understood that in larger -machines standard accessories, such as f oth skimmers etc can .be employed; The pr sent 7 go I rotating agitating element suspended in an aerating chamber, said chamber having at all points above the agitating means a periphery greater than the outside periphery of the agitating means, a housing supporting said agitating means from the top, said housing being provided with a horizontal arm. above the aerating chamber and supported by a vertical framework at the sideof said aerating chamber, the improvement which comprlse'sconnecting said arm to 'said framework through two'links of unequal length, the short link being pivoted in the horizontal arm and keyed at its other end to a shaft journaled in the frame and the longer link being pivoted in the horizontal arm and bn the framework intermediatethe journal of short link and the housing and means for rotating said shaft whereby the horizontal arm, housing and agitat--- ing element are first raised substantially vertically and then caused to tilt.

2. In an aerating :machine provided with a rotating agitating element suspended in an aerating chamber, said chamber having at all points above the agitating means a periphery greater than the outside periphery of the agitating means, a housing supporting said agitating means from-the top, said housing being provided with a horizontal arm above the aerating chamber and supported by a vertical framework at the side of said aerating chamber, the improvement which comprises connecting said arm to said framework through two links of unequal length, the longer link being pivoted in the horizontal arm and the framework and the short link being pivoted in the horizontal arm and keyed at its other end to a shaft journaled in the frame, means for rotating said shaft, the two links being so positioned when the agitating element is in its operative position that the link ends pivoted in the horizontal arm have a vertical component to the motion given them by the rotation of the shaft.

3; In an aerating'machine provided .with a rotating agitating element suspended in an aerating chamber, said chamber having at all points above the agitating means a periphery greater than the outside periphery of the agitating means,

- a housing supporting said agitating means from the top, said housing being provided with a hori zontal arm above the aerating chamber. and supported by a vertical framework at the side of said aerating chamber, the improvement which comprises the provision of lever means connecting said arm to said 'framework, mea-ns for moving said lever means, said lever means being so positioned when the agitating element is in its operative position that the ends of the-lever means connected to said horizontal arm have a vertical component to the motion given them by the lever moving means whereby the horizontal arm, housing, and agitating element are first raised substantially vertically and then caused to tilt.

JAMES JOSEPH BEAN.

Images