US1350204A - Slime-pulp thickener - Google Patents

Description

C. ALLEN.

SLIME PULP THICKENER.

APPLICATION FILED 0CT.10. 1918.

1,350,20 Patented Aug. 17,1920.

2 SHEETS-SHEET 1.

Eyj.

7 [71 z/erzzor- Charle /41km KQZZWZZ wdtfavm eys' Pdtented Aug. 17,1920.

2 SHEETS-SHEET 2.

In mentor Chqr'las'flllen To all whom it may concern:

, slime pulp in the PATENT OFFICE."

CHARLES ALLEN, or EL PASO,-TEXAS.

sLIME-PULP rHicKEivnR.

Specification of Letters Patent.

Original application filed June 9,1917, Serial No. 173,785. Divided and this application filed October I v i 10, 1918. Serial No.257,624.

Be it known that I, CHARLES ALLEN, a citizen of the United States, residing at El Paso, in the county of El Paso and State of Texas, have invented provements in Slime-Pulp Thickeners, which. the following is a specification.

This invention relates to a device for thickening slime or pulp,

closed in my co-pending application entitled, Slime pulp thickener, Serial Num ber 17 3,7 85, filed June 9, 1917, and of which ing of finely divided solids in suspension, is

almost universally used in the treatment of ores by wet milling processes, and in its every application it is of prime importance that the degree of thickening be uniform; that is, that the discharge of the thickened slime be always of the same eners heretofore used depend upon the volume of pulp fed to the cone or tank for regulation of the size of the discharge orifice. The results are very unsatisfactory, inasmuch as theproportion of liquids to solids in the material discharged varies with the volume of slime pulp fed to the thickener.

In the present invention, the volume of thickener in no manner alters the proportion of liquids to solids in the products discharged, within the limits of the capacity of the machine. The degree of thickening is' controlled, and forwhatever degree of thickening, the device is adjusted, that degree of thickening is automatically maintained.

In slime pulp, the finely divided solids move freely without the fluidity by friction among themselves.

Such a pulp has the properties of a liquid so long as the solids are kept in suspension.

hen the pulp iscomposed of water and solid particles of greaterspecific gravity,

than water, the specific gravity of the pulp "increases with all increasesin the quantity compartment a liquid, and in the other a of solids in suspension in the pulp! This pulp may therefore ,be considered as a liquid of greater density than water.- In my invention termed two compartments having in one mixture of liquid and solidsor pulp. The variations inthel density of the pulp, due

new and useful Imand particularly pertains to a structure :similar to that disdensity. T hickappreciably affecting overflows the rim of the tank. is provided to supply slime pulp to the I employ what :may be column of liquid, which column of liquid carries a float operatively connected to a valve at the bottom of the tank controlling the discharge orifice. When the pulp attains a certain density the valve is automatically opened to permit the discharge of the thickened pulp through the bottom ori- V lice, and when the density of the pulp falls below a critical point, the valve is auto-- matically operated to close the orifice. Hence the degree of thickening of the pulp discharged through the automatically controlled orifice is practicallytlie same under all conditions or variations in the volume of slime pulp fed into the tank. The

volume of thickened slime discharged through the'orifice may vary considerably, but the density of the thickened slime dis- 7 charged remains practically constant. This is the reverse of the thickener-s ordinarily used in which the volume of thickened slime discharged remains constant while the densityof the discharge varies with the quantity fed'into the thickener.

The invention isillustrated by way of example in the accompanying drawing in which- Figure 1 is a view in vertical section Patented Aug. 17, 19201 taken centrally of one form of the invention.

Fig. 2 is a view in vertical section taken centrally of another form of the invention, showing the actuating mechanism as disposed exteriorly of the tank.

Referring more particularly to the, drawing, the apparatus is shown as comprising a tank 10 in the shape of an inverted cone having a discharge orifice 11 at its bottom for carrying off the thickened product. A launder 12 is arranged around the top of the tank for carrying off clear liquid which A conduit center of the tank. The outlet 11. of the tank is indirectly controlled by a float 14 having variable buoyancy due to the application of adjustable weights 15. This float is provided with operable connections 16 Y which extend downwardly and engage the mechanismof a valve 17 controlling the discharge orifice 11. In the present instance the float is circular, being positioned within an annular chamber 18 which has outer and inner cencentrlcally spaced walls forming considerably above that of the rim of the tank and further extends downwardly to a level below the rim of the tank. This chamber is supplied with clear water through an inlet supply pipe 19.-

In'Fig. 1 the float chamber is supplied with pipes which extend downwardly through the conical top wall of the bell 21. he lower ends of these pipes terminate within an inverted conical receptacle '22 which telescopes into the bell 21, the

telescoping walls of the two members being spaced in relation to each other. The conical end of the receptacle 22 projects downwardly into the body of the pulp. hen the device is in operation the receptacle 22 as well as the tubes 20 and the float chamber 18 are filled with clear water. The overflow of water. from the receptacle 22 is prevented by an air cushion within the bell 21, the open bottom of which is sealed by the pulp within the tank. To prepare for the'thickening operation, clear water is admitted through the pipe 19 until the tank overflows, thereby filling the float chamber to the level of the overflow lip of tank 10, tubes 20 and the receptacle 22. The float is adjusted and the slime to'be thickened isturned into thetank through the conduit 13. As the slime thickens, its density increases, the level of the dense liquid passing above the mouth of thebell 21.

-The air within the bell is then compressed and acts upon the body of water in the receptacle 22 to raise the level of the same within the float chamber, thus lifting the float and opening the discharge valve.

The air cushion within the bell prevents the comminglmg of the shine with the clear water. This arrangement produces a structure not liable to readily wear or break and has proven to be execeedingly sensitive "to the variations in the density of the slime. It will be understood that when the density of the slime increases to sui'ficientlyaffect the clear water within the float chamber and to raise its level, the float 14 will be lifted to lower the valve member 17 and open the discharge orifice 11.' If desired,- a water gage may be provided for'the bell and a similar gage 24 provided for the receptacle, as shown in the drawing.

The form of the invention disclosed in Fi .2 embodies the use of a bell 25 simisions as compared with the tank and its upper portion represents a conical shell of these members are located within ing contamination of th clear water than those disclosed in Fig. 1 of the drawing or my co-pending' application abovementioned. It will be noted that the float chamber- 18 is cylindrical and is disposed exteriorly of the tank, there to receive a float 14. Both a supplemental tank 27. This tank communicates with the apex-of the bell 25 by means of a valved pipe 28 which enters the lower elidof the tank and terminates beneath the open mouth of the float chamber 18. Communicating with the pipe 28 is a pipe 29 which extends therefromand through an opening inthe top ofthe suppleinental tank- 27. This pipe is valved. and thereby insures that when an air cushion is to be used in trai'ismitting the pressure of one column of liquid to the other or where the air is dispensed with and water transmission is used, thepipe 28 may be employed.v In operation of the device shown in Fig. 2, when it is "desired to employ the air cushion, the valve in the pipe 28 is opened and the valve in the pipe 29 is closed. The float chamber and connected parts are then filled with clearwater through the supply pipe 19 until the tank10 overflows, whereupon the valve in the pipe 28 is closed and the ening then proceeds in themanner common to devices of this character.

\ 1 Variations in the density: of the" pulp above the bottom of the bell 25 will be trans- .m-i-tted through the air column to the surface of the water in the tank 27, thereby raising.

the level of the waterfin the-float chamber 18 and actuatingthe discharge valve. If no air cushion is to be used in the supplementary tank 27, the valve in the pipe29 is closed and. the valve in the pipe. 28,'per-; lar'in construction and operation to that i shown in my co-pending application entitled manently opened. Any excess of air press'urein the upper portionof the' t'ank 27 30. The-eifect of the difference in the denwill be expelledv through a controllablewent sity of the two columns is thus transmitted f n to the water through pipe28, theibelln25 being in this instance entirely filled with water. 7

It will thus be seen that I make use of a hydrostatic balance between two liquids of different densitiesto automatically control the discharge of the thickened product. Among the advantages of this system may be mentioned: First, that until the thickening hasprogressed to a certain definite density the orifice through which the thickened product is discharged remains closed, but as soon as the thickening has reached the desired point, the orifice is automatically opened. Second, if while the thickened product is being discharged, the degree of thickening falls below the required consistency, the discharge valve is automatically closed. Third, if the thickened product being discharged, increases or decreases in consistency beyond what is desired, the discharge valve is automatically moved to partial opening or closing position in order to restore the dischar ed product to the required consistency. ourth, the relative proportion of solids to water in the thickened product discharged is under perfect control by simply altering the float line of the actuating float, and for whatever proportion of water to solids the float is weighted, that proportion is automatically main tained. This means that the density of the thickened product discharged remains practically the same under all working conditions. It will be understood, of course, that the actuating float may be so built as to give a definite degree of thickening without varying the buoyancy thereof and hence the adjustable weights 15 may be omitted for a certain class of thickening, but means whereby the float line of the actuating float may be altered must be used in order to be able to adjust the thickener to various degrees of thickening.

Various changes in the construction and arrangement of the several parts herein shown and described may be employed with out departing from the spirit of my invention as disclosed inthe appended claims.

It is understood wherever the word water is used that I include in that term any other liquid or solution employed in practical milling operations and with pulp to be subjected to my process.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. A slime pulp thickener comprising a tank having a discharge orifice in the bottom thereof, a valve member normally closg said orifice, a float chamber, a float supported upon the liquid therein, operating mechanism between the valve and the float, means whereby variation in the density of the pulp liquid within the float chamber to raise the within the tank will afiect the float and an air-cell between said chamber and said means, whereby communication between the contents of tank and the contents of float chamber will be prevented.

2. A thickener for slime pulp comprising a tank having a controllable discharge orifice in its bottom for the escape of settled material, a chamber communicatin with said tank and adapted to receive a uid of lighter density than the pulp, a separating medium between the fluid and pulp capable of transmitting the pressure of the pulp to the fluid whereby variation in the density of the pulp is registered by the raising and lowering of the fluid in the chamber, and meansactuated by the rise and fall of the fluid for controlling the size of the discharge orifice.

3. A thickener for slime pulp comprising a tank having a controllable discharge orifice in its bottom for the escape of settled material, a chamber communicating with said tank and adapted to receive a fluid of lighter density than the pulp, a cushion of air between the pulp in the tank and the fluid in said chamber adapted to transmit the pressure of the pulp to the fluid whereby variations in the density of the pulp are v the rise and wall of the water in the chamber, and a float carried by the water in said chamber for controlling the size of the discharge orifice.

5. A thickener for slime pulp comprising a tank having a controllable discharge orifice in the bottom for the escape of settled material, a chamber communicating with said tank and adapted to receive clear water, a separating medium between the water and pulp capable of transmitting the pressure of the pulp to the Water whereby variation in the density of the pulp is registered by the rise and fall of the water in the chamber, and means for adjusting the buoyancy of the float whereby the density of the discharged material is regulated.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

CHARLES ALL N Witnesses:

J. L. ELY,

EDMUND SHAW.

Images