US1428929A - Dewatering and settling tank feeder - Google Patents

Description

J. R. WILKINSON, E. A. BARNARD, AND L. E. BOOTH. DlEWATERlNG AND SETTLING TANK FEEDER.

APPHCATlON FILED MAY 25. 1917- Patented Sept. 12,1922.

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1. a, vmxmsow, E. A. BARNARD, AND E. E. BOOTH. DEWATERING AND SETTLING TANK FEEDER.

APPLICATION FILED MAY 25 1917. I h fifi fia PatenmdSept. E2, 1922' 2 SHEETSSHEET 2 2% w hi Snow tom Patented Sept. 12, 1922.

UNITED STATES I 1,428,929 PATENT errant.

JOSEPH R. WILKINSON, ENOCI-I A. BARNARD, AND LIONEL E. BOOTH, OF ANACONDA,

MONTANA, ASSIGNORS OF FORTY-TW'O AND ONE-HALF PER CENT TO SAID "W'IL- KINSON, FORTY-TWO AND ONE-HALF PER- CENT TO SAD) BARNARD, AND FIFTEEN PER CENT T0 SAID BOOTH.

DEWATERING AND SETTLING TANK FEEDER.

Application filed May 25,

T 0 all whom it may concern Be it known that we, J osnrH R. lVILKIN- SON, ENOCH A. BARNARD, and LIONEL E. BOOTH, citizens of the United States, residing at Anaconda, in the county of Deerlodge and State of Montana, have invented certain new and useful Improvements in Dewatering and Settling Tank Feeders, of which the following is a specification.

In the concentration of ores by flotation, the pulp coming from the flotation-cells contains a certain amount of gas which inter feres with the subsequent recovery of the solids of the pulp. It is the present practice to send the flotation-cell-product to dewatering and settling-tanksto facilitate the recovery of the valuable contents of the pulp. Experience has shown that in the operation of settling-tanks the formation of froth on the surface of the liquid therein is a constant source of trouble and expense, interferes with the control of the feed, and that aneflicient settling of the solids is prevented.

It is the object of this invention to provide a method of and apparatus for feeding dewatering and settling-tanks which will avoid the occurrence of froth upon the surface of the liquid in the settling-tanks and allow of absolute control of the feed-volume.

The method hereinafter described for removing the froth comprises, briefly, the introduction into the system of a reservoir or reservoirs into which the pulp onits way to the settling-tanks is led, and wherein the entrained air or gas is removed. The degasified pulp is then conveyed into the settling-tanks to a point beneath the surface of the liquid therein. I

The preferred apparatus for carrying out the operation is shown in the accompanying drawings, in which Figure 1 is a plan view of a settling-tank in combination with one form of the dewatering and settling-tank reservoir;

Figure 2 is a side view of the same, part of the settling-tank being cut away to show the entry of the pulp to a point below the surface of the liquid;

Figure 3 is a plan view of another form of reservoir, the cover being removed;

Figure 4: is a side view of the same, partly in section, the cover being attached;

Figure 5 is a plan view showing a froth- 1917. Serial No. 170,940.

removing reservoir similar to that shown in Figs. 8 and 1 delivering pulp to a unit of six settling-tanks, and

Figure 6 is a sectional view of one of the series of reservoirs intended for the last tank or a series.

As shown in Figures 1 and 2, the apparatus comprises a pulp distributing-launder 1, a gas-removing reservoir 2 which receives the pulp through an inlet 3 from the launder 1, and which is provided with an over-flow opening 4. A switch 10 diverts pulp from the trough 1 into the'inlet 3. A pipe 5 connected to the bottom of the reservoir 2 and provided with a flow-control valve 5 serves to convey the degasified pulp 6 from such reservoirto a point, beneath the operatinglevel of a settling-tank 7. The latter may rest upon suitable supports 8, and a platform 9 is arranged in proximity to the apparatus to facilitate inspection and operation. A. spreading-baflle 11 is preferably so disposed opposite the outlet of the conducting-pipe 5 as to facilitate spreading of the incoming pulp.

The pulp flowing in the distributing feedlaunder 1 enters the reservoir 2-where the gas accompanying the pulp rises to the top due to the hydrostatic pressure in the reservoir. The dega-sified pul is then conveyed by the conduit '5 to a point beneath the surface of the pulp 6 in the settling-tapk 7 where an eflicient settling of the solids occurs; By means of the valve 5, the volume of feed to the settling-tank 7 can be readily controlled and this with the assistance of the overflow permits a constant level to be maintained in the reservoir-box 2. The valve 5, which may be a gate-valve, is so manipulated that there will be an overflow at all times. The froth accompanying the pulp and the excess pulp flows back, of course, into the launder and onto the next tank of the series until the end tank is reached, where the froth is finally broken down by a fine spray, as hereinafter more fully described.

As shown in Figures 3, a and 5, the apparatus comprises a central froth-removing reservoir 12 provided with a cover 13 and having partitions 14, 15, 16, 17 and 18 dividing the reservoir into a series of com partments 19, 20, 21, 22, 23 and 2 1. A feed launder 25 supplies the pulp to a distributing-launder 26 from Which the pulp passes into the respective compartments through inlets 27, 28, 29,30, 31 and 32, being effectively diverted thereto by switch- plates 33, 34,35, 36, 37 and 38, respectively. Delivery pipes 39, 40, 41, 42, 43 and 44, fitted at convenient points With suitable valves 39, 40', 41, 42, 43 and 44, convey the degasified pulp to the battery of settling- tanks 45, 46, 47, 48, 49 and 50, to a point beneath the opcrating-level of the pulp in each tank. The top edges 01": the partitions 14, 15,16, 1.7 and 18 are somewhat below the lowest point of the distributing-launders 26, so that above the partitions there is free communication between the several compartments.

The operation as carried out in, this arrangement is as follows: The pulp coming from the main feed-reservoir 25 enters the distributing -launder 26 passing through feed- inlets 27, 28,29, 30, 31 and 32 to compartments 19, 20 21, 22,23 and 24 of the centralreservoir 12. The gas contained in the pulp, due to the hydrostatic pressure in the reservoir, rises tothetop and the degasified pulp passes by the valved conduits 39, 40, 41, 42, 43 and 44 to apoint beneath the operating-level of the liquid in each settling-tank, Where efficient settling occurs.

The last of the series of reservoirs is equipped as shown in Figures 4 and 6, with automatic-valve-mechanism 55, to maintain.

. under normal Working conditions a constant pulp-level in the reservoir, this being necessary because of the variation in ti e vol.- ume of the feed. This valve-mechanism, operating similarly to Well known float-controlled-valves, is composed 01 a float 56 Which rests onthe surface of the liquid and controls the cone-valve 57. Since above the partitions 14, 15, 16, 17 and 13 the pulp can flow ,7 freely from one compartment to another, it Will be apparent that'the excess pulp Will be carriedto the end compartment 24 and cared for by the automatically operated valve 57. The gate valves regulating the flow of feed from the respective resersufiiciently voir-compartments are kept closed to keep the pulp levelabove the top of the compartment partitions, and insure a flow towards, the float and valve compartments. A spray of Water 24 Figure 6, is placed over the float in-the end-tank to break down any troublesome froth.

The introduction of the pulp. into the reservoir before its entry-into the settling-tank may eliminate all the gas from the pulp or it mayeliminate' the greater part, the remaininot part being light and non-troublesome. The degreeof elimination of the gas from the pulp is determined by the requirements of the plant and is controlled by the size and shape of the reservoir.

' It is obvious that a central reservoir may serve a battery consisting of any number of settling-tanks, a unit of six having been taken as shown'in Figure 5, merely for the purpose of illustrat on.

1. In apparatus for ore concentration, the combination of a plurality of settling tanks and apparatus for feeding pulp thereto free of gases by means .of hydrostatic pressure, said means comprising a vessel and partitions for dividing it into-a plurality of compartments, thesaid partitions terminating below the upper edge of the vessel, means for distributing the pulp into .said compartdifferent settling tanks. v i 2., Apparatus according to claim'2 including-means operative to destroy the froth in the constant level compartment.

In testimony whereof, We aflixour signatures. W f I V Josnrn n'Wi-LKmso ENOGHA. BARNARD. LIONEL n; scorn.

tions between the diiterent outlets and the i

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