US2609096A - Automatic flow control system for ore concentrators - Google Patents

Description

P 1952 E. c. BITZER 2,609,096

AUTOMATIC FLOW CONTROL SYSTEM FOR ORE CONCENTRATORS Filed Sept. 18, 1948 2 SHEETSr-SHEET 1 n-m 1N VEN TOR.

[o'mund C, Bi/zer ATTORNEY E. c. BrrzER v Sept. 2, 1952 AUTOMATIC FLOW CONTROL SYSTEM FOR ORE CONCENTRATORS Filed Sept. 18, 1948 2 SHEETS-SHEET 2 l l I l I l l l I l I [ea mL/na/ C. B/fzer w wk Patented Sept. 2, 1952 PATENT OFFICE AUTOMA TICFhOW CONTROL SYSTEM FOR T .1 J ORECONCENTBATORS Edinnnd'. CL Bitzer; Golden, 0010., assignor to Colorado Ironworks Company, Denver, 0010., a'corp'or'ationcf Maine ApplicationSeptember 18, 1948, SerialNo. 49,928"

. e I 1 v This invention relates to oreconcentratorsand dewaterers and-more.; particularly to improvementsrin controlling flow through a-concentraton such as shown in'the application Serial No: 20,472, filed April 12; 19%8,by ArthurJ Weinig. V

.In -the application identified, the concentrates are delivered from-the ccncentratorioutlet pipe,

trator must, ofcourse, bear an exact relationship toitherate of feeclof' pulp to the concentrator in'-:

order that the concentrator operate under opti-' mum conditions. If, for example, the rate of discharge fromthe concentrator exceeds theirate of feed of pulp thereto; the pump will tend to withdraw all the pulp through the concentrator and there will thus be no gangue or tailings overflow from the concentrator and hence'no-concentra tion. On the. other band ifthe rate of flow through the pump is less thanrequired-for optimum concentration, then there will beexcessive overflow from the concentrator and'much valu able ore will be-carried along with-the tailings; It is apparent, therefore, that withany Dredetermined'rate of p'ulpflflow to the concentrator; an

exact differential pressure must be maintained between theconcentrator overflow and the end of thevconcentrator discharge'pipein order that the concentrator operate most emciently.

In any-system which employs a'pumptozcarry the concentrates-the pump is-subjectecl toconsiderable' wear with its attendant! change in pumping, capacityibecauseof thefiabrasivenature: of the concentrateswhich pass therethrough; It. would therefore be of further advantage to'el-iini nate this pump", if possible;

The principal object of the present invention, therefore, is to provide a-nimprbved flow" control for a concentrator:

Anotherobjectis" to relate a? concentrator and dewa-te'rer in such manner that gravity head projdiic'es a" fiovflthrough the concentrator which head is" partially balanced by, liquid in the dc- Waterer';

. 1 Claim. (Cl. 209 455) Another object is to produce optimum flow through a concentrator without employing a v pump'which conveys solids.

A: further object is to relate the rate-of discharge'fro n a concentrator to the rate of feed of pulp-thereto by anarrang'ement Whichis auto-;

matic in operation and effects an exactnnchanging".ditferentialpressure which produces optimum flow' through the concentrator. v

Another ohjectis-to-provide an arrangementof a concentrator and'dewatererin which the rate oil now; through the concentrator may be" varied,

as desired, without the use ofza solids conveying pumypor solids conveyingvalve, i

Another object istoiarrange'the' discharge of aconcentrator with respect to a dewaterer in. suchrnanner that clogging of' theconcentrator discharge is eliminated.

Still further objects will become more apparent from a consideration of the description to follow, the} appendedv claim, and the{ accompanying drawing-,in-which: A

,,Ffigure.1' is ca planlview showing the relative positions of the several elements; Figure 2- is a section taken online 2-2 Figures l and'2; and:

Figure 3 is aside elevation taken'online 3 Figure nl with parts thereof broken away and shown in section.

In the drawing reference character C,desig.-

nates a concentrator of the general type shown and-describecliin the application above identified andifp is. a dewaterertor classifier of the screw typelasishown at; l -Liwith the conventional discharge.l2fat1its upperendover which flows dewat'ered solids. This" dewatereris representative of such devices of which there are many specifically different constructions available-and which differ from the" one shown principally inthis;

V that rake's'. or f conveyor belts are substituted'for Concentrator; C has an overflow spout 0; near itsjtop ove'r whichflbw's isurplus water and gangue or tailingsfand' anloutlet pipe in" at" its bottom through whichflows .theiconcentrates for delivery to the-dewaterer. The dewaterer is? provioldwith an' outlet-lt lielowdevel LC of thefconcentrator and" a van-e15 isconnected thereto which, by proper; adjustment;- will' niaintair'iany desired levelintthe 'dewaterer such as the level LD; It"

is-ttoiibe'" partieularly"notedlthat valve totcon'veys watenonly'; rather than solids; becauseiseparationof solids and the liquid delivered-fronithe: cone centrator takes place in the dewatererythe solids v being dewatered and conveyedover upper edge [2 and the Water being discharged through outlet specific gravity of the material in the concen-' trator and pipe 10, and the resistance which the pipe and concentrator ofier to fiow. This head concentrator and dewaterer are connected together by an inclined pipe l0. This inclined pipe forms the shortest possible straight connection between the two machines and thus prevents any clogging taking place therein as might occur with the use of a horizontal run of pipe, elbows, or other fittings which tend to. obstruct fiow.

While the invention has been disclosed witha dewaterer having a variable level, it is to be understood that other devices which provide a balancing fluid column could also be employed.

is partially balanced by the head of the material 7 in the dewaterer which is similarly determined, the distance between LD and the bottom of pipe 10 being one of the factors.

The relative levels of LC and LD will, of course, vary according to the nature of the ore being treated and the rate of flow desired through the concentrator. the flow and raising the level will decrease the flow. No countercurrent flow should ever exist in pipe In which would carry fines upwardly to be ultimately lost in the gangue or tailing overflow 0. Normally the level LD would be below LC by a distance it to produce the desired fiow. It may of course be lowered by a distance h which is determined by the position of outlet 1 3. Also, in some cases it may be desired to raise this level a distance h" above level LC. For example, if the specific gravity of the material in the concentrator and its discharge pipe is considerably greater than the specific gravity of the material in the dewaterer then a theoretical static balance of the respective columns would occur when the two heads are in proportion to their specific gravities, that is level LD would be higher than LC. This would produce no flow, how-ever,

hence h" would always be of such a value that some differential pressure would exist to produce flow.

A pump I4 is connected to overflow I3, but it is apparent that this pump does not control level LD in the embodiment previously disclosed. The pump merely delivers discharged fiuid to any convenient point in the system, for example, through pipe to a tank T for subsequent return to the concentrator through valve P. This return is illustrative only and it is apparent that the water from overflow l3 may be delivered to any place desired and that water supplied by valve 1?,when employed, may be received from any suitable source. The control of level LD by means of a valve has been shown for illustration only, this beingprobably the simplest form in which the invention may be disclosed. It now becomes apparent that many other forms of level controls could be employed such'as an adjustable weir or adjustable syphon having one leg thereof which would determine level LD. Also, an adjustable float could be employed which would maintain level LI) as desired, as well understood in the art'of level controls. Under certain circumstances it may also be desirable to control the level LD responsive to changes in the specific gravity of the material in the concentrator. Thus, if a portion of the pulp feed should change in specific gravity, the rate of flow through pipe would change if the level LD remained constant. Any suitable means known in the art, which would sense such change in specific gravity could be employed to regulate valve [5 so that flow conditions through pipe l0 would remain constant even with variable specific gravity of the pulp.

It is to be particularly noted, also, that the Lowering of level LD will increase.

Thus, the dewaterer might have a secondary function of classification of the ore concentrates hence the term dewaterer as used in the claim is to be given its broadest and most generic meaning within the spirit of the invention.

' The present invention is to be distinguished from prior art arrangements wherein a concentrator delivers concentrates by gravity fiow to a dewaterer. In these prior art devices there is no control of an optimum level of liquid in the dewaterer. Since the concentrates which are delivered to the dewaterer may be, for example, 50% solids and 50% water, and the dewatered material which is conveyed over the discharge l2 of the dewaterer may contain of the order of 80% solids, it becomes apparent that there is an excess of water being continuously delivered to the dewaterer which must be discharged somewherein the system. The gangue overflow in the ;concentrator being the only place where this centrator there is a flow of water in the opposite direction through this conduit. This counterfiow of water carries with it certain of the fines which are carried over the gangue overflow of the concentrator and are thus either lost or necessitate 1 W further separation from the gangue if it is desiredto recover them. The present invention, on the other hand, provides an exact control of flow conditions in the concentrator discharge conduit.

The provision of discharge l3 and control of level LC provide an arrangement which effects exact control of the fiow conditions in discharge conduit l0. Thus, as previously mentioned, if it is desired to recover the fines along with the concentrates, which is usually the case, the flow conditions can .be so regulated that no counterfiow exists in conduit I0 and all of the fines will :be delivered to the dewaterer. It is, of course, apparent that the present invention could be employed, also, to achieve substantially the same results as described for the prior art. Thus, if it should not be desirable to recover the fines; or a laterally spaced relation, the concentrator having agangue overflow at certain level and a con centrate discharge opening at a lower level, the gangue overflow and the concentrate discharge opening being in communication by a teeter col- 6 REFERENoE s CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,031,113 Garred July 2, 1912 1,491,296 France Apr. 22, 1924 1,541,237 Trott June 9, 1925 1,917,819 Barr July 11, 1933 2,302,588 Weber Nov. 17, 1942 2,417,660 Remick Mar. 18, 1947 2,460,801 Bitzer Feb. 8, 1949

Images