US1468844A - Classifier - Google Patents

Description

R. s. TROTT Sept. 25, 192s cLAssIFiER Filed Feb. 7, 1922 :3 Shee ts-Sheet 1 INVENTOR.

R. S. TROTT .cLAssIFIER Filed Feb. '7, 1922 5 Sheets-Sheet 2 (h M Mal -M lNVE/VTOR Sept. 25,1923.

R. S. TROTT CLASSIFIER Filed Feb, 7; 1922 3 Sheets-Sheet 5 /VENT@ R the whole mass is merely agitated.

Patented Sept. 25, 1923.

warren stares- ROLLAND SJTRO'IT, OF DENVER, COLORADO.

CLASSIFIER.

Application filed February 7, 1922. Serial No.,534,770.

such a. classifier to give great adaptability over a wide range of conditions as will appear below.

In the ordinary reciprocatingrake classifier, the rakes, which operate in a sloping box or vat, rake the settled material upward along the slope to the sand discharge end of the machine, which is above water level.

The'lighter material and liquid overflow at the opposite end of the classifier, the feed being put in at an intermediate point.

Between the strokes of the rakes the matcrial has a chance. to settle, and it is this settled material which the rakes move upward toward the sand dischargeend of the classifier.v

As the rakes intermittently move the settled material upward along the slope .and below the water level, a washing action takes place, tending to clean the sand.

The time required for proper settling under these circumstances naturally varies with the material being treated, the percentage of sand and slimes therein, and the fineness to which it has been ground. If, with a certain material, the rakes are reciprocated so fast that there is not enough time between strokes for proper settlilng,

or suspended material runs back as fast as the rakes move it up the slope, and hence no classification takes place.

In such a case the only thing to do is to reduce the number of strokes per minute of the rakes till enough time is given the material in question for proper settling between strokes.

As the amount of material the rakes canof strokes per minute, this naturally reduces the capacity of the classifier.

In my classifier this loss of raking capacity is made up for by lengthening the stroke of the rakes, as the number of strokes per minute is decreased, as will be explained below. I

Hence, in my classifier, by lengthening the stroke as required, the raking capacity may be maintained the same, and the settling requirements of any material may be met.

This means not only good classification, but'good capacity as well, regardless of the material being treated.

I obtain these advantages bv a construction in which the rakes are suspended from wheels that roll upon a sloping, vertically movable track which is held at its lower position while the rakes are moving upward along the slope of the track, and-which is held at its upper position while the rakes return toward the lower end of the track.

The movable track is made long enoughto stroke of the rakes, is to change the oficenter position of the crank pin which is connected to the rakes by a connecting rod. The extreme limit of travel of the rakes in either direction may be maintained unchanged if desired by proper adjustment of the connecting rod length as the stroke length is altered.

In the drawings, Figure 1 is a side elevation of my classifier, partly in section; Figure 2 is a plan view of the same, and Figure 3' is a front elevation. Figure 4 is a fragmentary view of the modified parts of a modified form of the track and roller connection between the rakes and the bell cranks.

-The rakes 1 are suspended from the wheels 2, which roll back and forth upon the track 3, when driven by the connecting rod 4 and the crank pin '5.

'lhe crank pin 5 is made as an integral part of the plate 6, which is bolted to the face of the cam 7. Extra bolt holes are provided to allow the crank pin 5 tobe shifted along the line X.X as desired to vary the length of stroke of the rakes 1.

Any other proper method of changing the throw of the crank pin 5 may be used provided it retains the crank pin 5 some place upon the line X-X so that its angular relation to the cam 7 will remain unchanged.

The cam 7 is mounted upon and keyed to the shaft 10, which is properly journaled and is revolved by gearing or any other proper method of power drive.

The bellcrank 12, mounted on the fulcrum 13, carries on one of its arms the pivotally mounted lever 14, which carries the roller 1 designed -to roll upon the cam 7. The

same arm of the bellcrank 12 carriesthe clevis 15 and the adjusting screw 12*, which bears against the lever 14, The other arm of the bellcrank 12 is provided with the clevis 16.

The bellcrank 17 is provided with the clevis 18, the clevis 19 and the fulcrum 20, upon which it is mounted.

The adjustable link 21 is provided with a clevis at its lower end and passes through the pin 18 in the clevis 18, theyelfective length of the link being adjustable by movement of the threaded nut 21.

The track 3, preferably of circular cross section, is at its one end pivotally mounted in the clevis of the adjustable link 21, and at its opposite end it is pivotally mounted in the clevis 15 of the bellcrank 12.

The clevis 19 of the bellcrank 17, is pivota-lly connected to the clevis 16 of the bellcrank 12 by the rod 22, which is provided with the turnbuckle 22, or withother means to adjust the rod length.

The tongue and clevis of the above mentioned pivotal connections may be reversed, or other proper form of pivots may employed if desired.

The wheels 2 put the weight of the rakes on the track 3, and thus through thebellcrank 12, the adjusting screw 12 and the lever 14 cause the roller 14 to bear against the cam 7, not only through the weight supported by the bellcrank 12, but also through the action of the adjustable link 21, the bellcrank 17 and the rod 22 in supporting the opposite end of the track 3 and that end of the rakes.

It will now .be seen that the cam 7 is.de-'

signed to raise both ends of the track 3 when the rake 1 is at the upper end of its travel, and to keep it raised till the rake 1 has returned to the lower end of its travel, when the cam 7 then lowers the track 3 and keeps it in that position till the rake 1 has again reached the upper limit of its travel on the track 3, and so on. I

It will be noted that the cam 7 has a very simple duty to perform, and hence has no contours likelyto menace long life and smooth running. 1 1 v The height of both ends of the track 3 may be altered as desired by the proper adjustment of the screw 12. And the angle of the track 3 with the slope of the vat 23 may be altered as desiredby proper adjust.

assess;

ment of the nut 21 of the adjustable link 21, or by the adjustment of the length of the rod 22 by the turnbuckle 22.

These adjustments may be required under operating conditions, and they serve to give 7 the machine even more adaptability to meet any and all requirements of the materials to be treated.

At the'sand discharge end of the classifier, between the water level and the sand discharge lip 23 there is provided in the floor of the vat 23, the porous screen 24.

It is well known that a filter in this position will clog up and become practically useless in a very few minutes, for which reason there are none in use at the present time.

In my invention I use a screen that is porous; that is, the holes through it are perhaps several times the size of the largest particles fed to the classifier.

The result is that as the sand is raked up the slope and upon this porous screen, leaking of sand through the said screen takes place till the next stroke of the rakes carries it up over the discharge lip 23, and brings a new quantity of sand upon the screen.

I prefer that this porous screen 24 be made i of a steel plate provided with slots or holes, though certain types of wire screens may be used if desired, or any other porous mediuuu It has been observed that in reciprocating rake classifiers most of the water in the sand at the discharge lip lies in the first half inch directly above the fioor of the vat. That is, in its movement by the rakes up along the slope from the water level the water in the sand quickly drains down to the bottom of the sand bed, as it naturallywould in any sand bed.

It is this fact that has caused so many trials of a filter in the floor of a classifier, all of which trials have resulted in failure because the filter could not be kept clean, but quickly became so'clogged as to be practically useless for drying the sand.

So, in my porous screen I do not attempt to extract the moisture from the sand, but merely separate the bottom of the sand bed which is wet, from the top of the sand bed 1 which is relatively dry.

In my porous screen, the action f the rakes in raking the-sand upward, forces a the number of strokes per minute of the rakes. Ifthis relationship is obtained, the sand seems to run through the openings of the screen a certain amount and then forms a bridge over each hole, which greatly checks the amount of sand that passes through the screen. This forms a. sort of moving sand filter through which moisture may pass down to my porous screen in the short time remaining before the next rake stroke.

The sand and water which thus pass through my porous screen is returned by the sand pump 25 or other such means to the feed launder 26, and thus back to the classifier, or may be returned direct to the classifier without entering the feed launder 26.

So the leakage through my porous screen, both water and sand, is in closed circuit with the classifier, and only the dryer portionof the sand raked up the slope is allowed to pass over the sand discharge lip 23, after the wet portionof the sand has been separated from it.

WVhen slow settling material is being treated, the crank pin 5 may be moved along the line XX till the stroke of the rakes is long enough t make the required sand delivery at the low number of strokes per minute re quired to give the material time to settle between strokes.

In general, the slower the settling, the finer is the material, and the slower the contained water will drain to the bottom of the sand bed.

But, in my classifier, this material may be moved by a long stroke of the rakes which will not only give along time between strokes to permit settling, but will also give a long time between strokes topermit proper draining of the Water to the bottom of the sand bed.

Thus, my classifier may meet both the settling and the drying requirements of such material by proper adjustment'of the stroke of the rakes, and the number of strokes per minute.

My porous screen may be inclosed and put under a vacuum if desired, but I prefer the construction shown, as the desired drying capacity, or separation of the wet sand from that relatively dry may generally be obtained by variation of the size of the screen openings and the number of strokes of the The overflow from the classifier takes place over the edge 27 of the vat 23, and over the edges 28 of the launder 29, which is let into the sides of the vat 23 till ne or both edges are ator. near the level of theedge 27, the passage of the launder 29 through ,the walls of the vat 23 being made watertight. This arrangement gives a. great length of overflowedge and prevents channels and localized currents when a great quan'tity'of material is being handled by the classifier.

The above described classifier is of the single type, but naturally it may be made in the duplex type as well, by the combination of two single classifiers and preferably alternate movements f their rakes, as anyone versed in classifierswill understand.

Iam aware that the track 3 may be mount ed integral with the rakes 1, and the rollers 2 may be mounted in the clevis 18 of the bellcrankylT and in the clevis 15 of the bellcrank 12, so that the bellcranks will sup port the track 3 through the rollers 2, as illustrated'in Figure 4.

But, this does not depart from the essence of' my invention so I do not wish to confine the construction to the exact design described, but what I claim as new, and desire to protect by Letters Patent, is as follows 1. In a classifier, a sloping vat, bellcranks mounted upon said vat, a track supported by said bellcranks, rakes supported by said track,a shaft-mounted on said vat and provided with a crank pin with adj usta-ble throw, means connecting said'crank pin and said rakes to reciprocate said rakes, a lever pivoted upon one arm of one of said bellcranks and provided with a roller, adjustment means between said lever and the bellcrank upon which it is mounted, and means.

forming a track for said roller and operated by said shaft to actuate the said bellcranks andraise and lower said"rakes at predetermined points in their travel.

2. In a classifier, a sloping-vat. a pair of bellcranks mounted upon said vat, a track suported by said bellcranks, rakes supported by said track, a shaft mounted on said vat and provided with a crank pin with adjustable throw, means connecting said crank and said rakes to reciprocate said rakes. a lever pivotedupon one arm of one of said bellcranks and provided with a roller. adjustment means between said lever and said bellcrank, adjustment means in the connection between the bellcrank and the other end of said track. and means operated by said shaft and acting through said lever, said adjustments and said bellcranks to raise and lower said track at predeterminedpoints in the travel of the said rakes.

3. In a sloping tank classifier. rakes, supporting means, track and roller means extending longitudinally above the center line of said rakes and connecting them with said and roller connections and said rakes, and a supporting means, means to raise and lpwer crankpin attached to said cam and connected said sup orting means, and means to recip to said rakes to reciprocate them.

rocate said rakes and thereby impart rela- 9. In a sloping tank classifier, bellcranks tive movement to the track and. roller ele j pivotally mounted above the tank, a power ments of said centrally located track and driven cam, rakes, centrally located selfroller means. 1 aligning roller and track connections be- 4. In a sloping tank classifier, rakes, suptween the longitudinal center line of said porting means, .track and roller means cenrakes and said bellcranks, means operated 1. ,trally located above the longitudinal center by said cam and operating said bellcranks to line of said rakes and connecting them with raise and lower said connections and said said supporting means, means to reciprocate rakes, and means mounted on said cam and said rakes-and to vary the length of said connected to said rakes to reciprocate them. reciprocation, and means to raise and lower 10. n-a sloping tank classifier, bellcranks said supporting means at predetermined pivotally mounted above the tank, a power points in the travel of said rakes. driven cam, rakes, self-aligning roller and 5. In a classifier, a vat, bellcranks mount- Z track connections between the longitudinal ed above the vat, rakes, roller and track concenter line of said rakes and said bellcranks,

nections in a single line above the longitudimeans operated by said cam and operating 20 nal center line of said rakes and forming a said bellcranks to raise and lower said conself-aligning connection between said rakes nections and said rakes, and means mounted and said bellcranks, means to reciprocate on said cam and connected to'said rakes to said rakes and to adjust the travel of said reciprocate them. reciprocation, and means to oscillate said 11.--In asloping tank classifier, bellcra'nks 25 bellcranks and thereby raise and lower said pivotally mounted above the tank, a power rakes at predetermined points in their redri en Cam, rakes, self-aligning roller and ciprocation. track connections between the longitudinal 6. In a classifier, a sloping vat, a tr k center line of said rakes and said-bellcranks, mounted centrally above said vat, rakes, ns operated by Said cam and operating bellcranks mounted abov said vat, roller said bellcranks to oscillate them, and means as adapted to cooperate with said track and n sa d can'l and c nnect d to said rakes to xform a central, self-aligning connection be reciprocate them.

' tween said rakes and said bellcranks, means 12 III & C sifi a ng e movable rack, to reciprocate said rakes, and means to oscilmeans f r v g h rack, and a movable 35 late said bellcranks and raise and lower said a s ppor ed by the track.

self-aligning connection at predetermined 13, In a classifier, a sloping, single, movpoints in the travel of said rakes. able track, means for bodily lifting'the track 7, I a l ifi a l i b tt d t k at intervals, and a'movable rake supported provided with an overflow, a sand discharge y h trackabove the level of the overflow, and feed 14. In a classifier, a sloping, single, movmeans intermediate the overflow and the able k, means v y g the slope 0f sand discharge, bellcranks pivotally mounted Y the track and a movablerake supported by above said tank, a power driven cam, rakes, the track track and roller means located above the I a classifier, a Single movable. track, longitudinal center line ot'said rakes and means for moving the track and a movable forming a self-aligning connection between rake supported by the track, in combination the rakes and the said bellcranks, means With a trough adjacent the bottom of which operated by said cam and operating said he rake travels in one of its movements. bellcranks to raise and lower said rakes, a 16. In a classifier, a sloping, single, mov- 50 crankpin attached to the side of said cam able track. meansfor bodily lifting the track and radially adjustable thereon. and means at intervals, and a movable rake supported connecting said crankpin and'said rakes to by the track, in combination with asloping reciprocate said rakes. trough, adjacent the bottom of which the 8. In a classifier, a sloping bottomed tank rake traverses in one of its movements.

. provided with an overflow. a sand'discharge 17. In a classifier, a single movable track, 1 0

above the level of the overflow, and feed means for moving the track, amovable rake means intermediate the overflow and the supported by the track and means to vary sand discharge, bellcranks pivotally mountthe length of the movement of the rake.

ed above said tank. a power driven cam, 18. In a classifier, a. sloping, single, movrakes, track and roller means located above able track, means for bodily lifting thetrack 1 the longitudinal center line of said rakes at intervals. and a movable rake supported and forming a self-aligning onnection be-' by the track' and provided with meansvto tween the rakes and the said bellcranks, vary the length of its movement. means operated by said cam and operating 19. In a classifier, a sloping single mov-- said bellcranks to raise and lower said track able track, means for varying the slope of the track, and a movable rake supported by the trackand provided with means to vary the length of its movement.

20. In a sloping tank classifier, a tank, rakes, supporting means mounted upon said tank, track and roller means extending longitudinally above said rakes and connecting-them with said supporting means, means to raise and'lower said supporting means, and means to reciprocate said rakes and thereby impart. relative movement to the track and roller elements of said track and roller means.

21, In a sloping tank classifier, rakes, supporting means, track and roller means located above the said rakes and connecting them with said supporting means, means to reciprocate said rakes and to vary the length of said reciprocation, and means to raise and lower said supporting means at predetermined points in the travel of said rakes.

22. In a classifier, a vat, bellcranks mountabove the vat, rakes, roller and track connections above said rakes and form ing a self-aligning connection between said rakes and said bellcranks, means to reciprocate said rakes and to adjust the travel of said reciprocation, and means to oscillate said bellcranks and thereby raise and lower said rakes atpredetermined points in their reeiprocation.

23. In a sloping tank classifier, bellcranks pivotally mounted above the tank, a power driven cam, rakes, self-.a'li 'ing roller and i: said rakes and the said bellcrank s, means operated by said cam and operating said bell-cranks to raise and lower said connections and said rakes,

,and means mounted on said cam and con-v nected to said rakes to reciprocate them.

24. In a sloping tank classifier, bellcranks pivotally mounted above the tank, a power driven cam, rakes, self-aligning roller and track connections between said rakes and said bellcranks, means operated by saidcam and operating said bellcranks to oscillate them, and means on said cam and connectedto said rakes to ciprocation;

25; The process of classifying material containing granular elements to obtain a vary the length of said re relatively dry discharge, which consists of introducing the material into a sloping tank provided with an overflow for liquid and the finer parts of said material moving the malayer-will be delivered. beyond said pervious member.

26. The process of classifying material containing granular elements to obtain. a relatively clean, dry discharge, which consists of introducing the material tank provided'with an overflow for liquid and the finer parts of said material, moving the material which settles, slope of the tank and above the level of said overflow, and then over a pervious member, the perforations of which are larger than the largest granules of said lower wet layer of said material will pass through said pervious member and'be conveyedl back. to said tank, and the relatively dry material above said lower layer will be delivered beyond said pervious member,

27. The process of containing granular elements to obtain a relatively dry-discharge, which consists of introducing the material intoa tank provided with a liquid bath, '-moving the material which settles, a pervious member, the perforations .of which are larger than the largest. granules of said material, whereby a lower wet layer of said material will pas through said pervious member, and the relatively dry masaid lower layer will be deinto a slopingclassifying material out of the bath and then over.

upward along the v material, whereby a atively dry discharge, which consists of introducing the material into a tank provided with a liquid bath, moving the material which settles, out-of the bath and then over a pervious member, the perforations of which are larger than the largest granules of said material, whereby a lower wet layer of said material will pass throughsaid pervious member and bebath, and the relatively dry material above the said lower layer'will be delivered beyond said pervious member.

ROLLAND S. TROTT.

conveyed back to the

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