US 2179807 A
Description (OCR text may contain errors)
Nov. 14, 1939.. 1y ASMUSSEN 2,179,807
GENTRIFUGAL VIBRATOR Filed Feb. 9,'1958 WWW/[Ill A Jes Asmussen INVENTOR ATTORNEY.
rented Nev. 14, w39
UNITED STATES oENrmrUcAr. vmmiron Jes Asmussen, Milwaukee', Wis., assigner to A. 0.
Smith Corporation, Milwaukee, Wis., a corporation of New York Application February 9, 1938, Serial No. 189,563
4 Claims. (Cl. 233-5) This invention relates to an improved apparatus for classifying ores in which centrifugal force is applied to concentrate particles having a high specilic gravity such as gold and precious metals.
t In this machine the ore containing pulp is forced into riille grooves, the contour of which is changed at periodic intervals to vibrate the concentrates and reclassify the particles deposited.
llt is anV object'of the present invention to prol vide an improved machine for concentrating ore particles.
A further object is to provide a concentrator with rimes lor collecting ore particles, the contour of which may be changed by the application it of hydraulic pressureto agitate the concentrates.
Still another object is to provide a fluidcontainer dehning a rime surface on one side thereof, which may be displaced by variations in the uid l pressure to either widen and narrow the grooves 2o between rimes or to lessen the depth of the riiile grooves.
Itis also the object of this invention to provide a centrifugal concentrator with horizontal riilies arranged on the inside of the bowl which may be 2g periodically vibrated at intervals independent of the speed of rotation of the bowl.
One embodiment of the invention is illustrated in the accompanying drawing which is a vertical cross sectional view of a rotary bowl, the section au being taken along the axis of the bowl.
Referring to the drawing the bowl l is mounted on a vertical shaft 2 journalled in any suitable uit i 'u t. The method of mounting and rotating the bowl forms no part of this invention and l 3g the apparatus illustrated is intended to be more or less diagrammatic. Rotation of the bowl may be edected by a pulley t mounted on vthe shaft 2, driven by a belt 5 connected to any suitable power means.
M used around the inside of the bowl and suspended from the top where it is clamped between the danged rim t of the bowl and a ring l by means -of a number ofbolts 8 is a bellows 9 of ber or similar material. vThe outer wall of 4p the bellows lies Hush against the inner wall of the bowl, while the inner wall of the bellows is formed to provide a series of rimes extending around the bowl transverseto the bowl axis. The rime sleeve formed by the inside of the bellows must be ,5o hexible and for this purpose rubber is well adapt- 55 having their inner faces attached to the most exy tended portions of the riilles. The members I0 are more rigid than those sections ofthe riiiles which lie between the supported portions and form the base of the rillie grooves. Accordingly these members, when made of the same material 5 as the rimes, are thicker in cross section than the base of the grooves, but it is contemplated that they may be the same thickness when made of harder material.
The cuter ends of the annular members l0 are l0 spaced a slight distance from the outer walls of the bellows to permit communication between the chambers created by such members. Notches may be' provided in the outer periphery of the members l0 at various intervals to facilitate this 15 communication.
The lowest rile is spaced some distance above the bottom of the bellows with the result that there .is a fairly large sized chamber Il below the first rime-supporting annular member. The volume of iiuid contained in this chamber must be maintained substantially constant and consequently the walls are preferably made of fabric which will resist expansion upon the application of internal pressure.
Stretched across the bottom of the bowl and connecting the inner sides of the bellows at a point a short distance below the first riilie is a sheet l2, likewise of rubber or similar material. 'I'his sheet may be formed as a continuation of the inner wall of the bellows as illustrated in the drawing. Chamber Il is constructed below the riies and the sheet i2 in order that the pulp thrown out in the bowl 'will not impinge against the walls of the chamber to distort its contour or affect .35 the pressure within the bellows. Consequently the external pressure on the chamber ll will be maintained. at substantially uniform atmospheric pressure, and the variations in internal pressure .may be accurately controlled.
packing to prevent leakage.
The pressure system just described may be economically operated with water as the fluid medium. With a bowl adapted to be operated in the neighborhood of 1000 revolutions per minute, variations in fluid pressure are caused to occur at a rate of around 100 to 120 per minute.
Pulp is fed to the bowl by means of the centrally disposed feed pipe I1 which discharges a slight distance from the bottom of the bowl. As the bowl is rotated the pulp is forced outwardly and upwardly over he riilie surface surrounding the interior of the bowl and finally flows over the top. Any suitable basin may be provided for discharged pulp such as a trough surrounding the bowl. No such means are shown because they are conventional and well known by those familiar with this art.
Ordinarily if the riile contour remained unchanged during the concentration of the ore. particles of heavier specific gravity would be thrown into the grooves between riies together with sand and other lighter undesirable particles. 'Ihis mass of particles soon becomes solidly packed in the grooves and further classification becomes impossible.
By varying the pressure in thebellows, the contour of the riies may be changed a number of times during the process to loosen up the particles deposited in the grooves and eventually to work the lighter particles out of the bowl,
with the result that better classification ofheavier, desirable particles can be obtained. Increasing the pressure lengthens the bellows spreading the riles apart and creating a shallower, broader groove, which permits the pulp stream to sweep out lighter particles. At the same time a broader surface is provided for the deposition of additional heavier particles from the pulp stream.
When the pressure is decreased, the rimes resume their original position and the grooves are deep and narrow, retaining heavier particles and expelling lighter particles. Pressure impulses are controlled by the diaphragm pump entirely independent of the speed of rotation of the bowl and may be varied for different ores and under different working conditions.
The invention having been described what I claim and desire to secure by Letters Patent of the United States,'is:
1. In a rotary bowl for classifying materials of different specific gravities, a flexible sleeve defining a series of rlles arranged transversely to the bowl axis, said sleeve being disposed inside said bowl and spaced therefrom, a fluid chamber between said riilies and the sides of the bowl, and means for changing the contour and width of the riilies by varying the ui pressure in said chamber. f r
2. In a rotary bowl for classifying materials of different specific gravities, a bellows of flexible material disposed around the inside of the bowl and adjacent the walls thereof, said bellows having a series of riles arranged on the inner side thereof, fluid medium maintained within said bellows, and means for varying the pressure of said uid medium to varyl the contour and width of the riiiies.
3. A centrifugal concentrator which comprises a bowl, a flexible riiile sleeve disposed around the inside of the bowl and radially spaced therefrom, a uid chamber between said riiile sleeve and said bowl, spaced annular members reenforcing said riiie sleeve and forming a number of compartments in said fluid chamber, the, reinforcing members carried by said flexible riiiie sleeve being free to move axially upon the lengthening or 'shortening of the sleeve, means for fluid communication between said compartments, and means for varying the fluid pressure within said chamber to flex the riiiies and agitate the ore particles deposited in the riflies by varying the length of the sleeve and correspondinglyvarying the width of the riiiles. t
4. A centrifugal concentrator of the rotary bowl type which comprisesa bowl, a bellows suspended inside said bowl, the inner surface of which has a series of riies arranged transversely to the direction of flow of ore pulp in the bowl, fluid medium maintained within said bellows, a
pump, and means for transmitting pressure impulses from said pump to said bellows to open and close the grooves between said riftles.