US2271417A - Dewatering and classifying conveyer - Google Patents

Description

Jan. 27, 1942. R. w. DULL DEWATERING AND CLASSIFYING CONVEYER 3 Sheets-Sheet l Filed Feb. 10, 1940 me wwwa.

Jan. 27, 1942. R. w. DULL DEWATERING AND CLASSIFYING CONVEYER Filed Feb. 1o, 1940 5 Sheets-Sheet 2 I7? vena?" Jan. 27, 1942.l R. w. DULL DEWATERNG AND CLASSIFYING CONVEYER Filed Feb. 10, 1.9740 3 Shee`tS-SheetI 3 I7@ ven-07" .7

Patented Jan. 27, 1942 UNITED sinfrles- PATENT j OFFICE n I lloEWlrrlmngr i' Raymond Dull, La Grange, lll.

Y Application February 10, 1940, Serial No.v318,3l3

13 Claims.

' My invention relates to improvements inl de'-v operating mechanism, and to provide means1 in connection with such apparatus for lubricating the supporting and moving parts, and to provide means for increasing themlife of the apparatus.

' My invention is illustrated more or less diagrammatically in the accompanying drawings, wherein:

Figure 1 is a longitudinal section with the drive end shown in side elevation. y

Figure 2 is a plan view of the device shown in Figure 1.

Figure v3 is a section Figure l.

Figure 4 is a detail longitudinal section of a modified form of my device.

Figure 5 is a section along the line 5-5 of Figure'4.

along the line 3 4 of Figure 6 is a section along the line 6 6 of` I, 5, a feed floor E', and a discharge floor 1, the ffeed floor being more sharply inclined to the horizontal than the discharge; M are a series of'y "wearing strips extending throughout the lengthof the trough from feed to discharge end andvprojecting slightly'above floors i and l and removably mounted thereon. 9 9 are aseries of water or liquid supply pipes discharging inwardly and upwardly through the discharge oor of the tank, and receiving water under pressure through the pipes I0 from any suitable source of supply, such as pump Il.

l2 is an endless belt adapted to rest upon and travel along the wearing strips 8. This belt travels over the belt driving pulleys I3, Il, supported on the frame I5, and the idler pulley Il between the pulleys I3 and Il, the pulleys Il and M. are driven by drive chains I1 traveling over cated, Vbeing driven by any suitable source of power. The'pulley Il is tangent to the floor 6 so that as the belt, I2 leaves the pulley Il it is discharged along a lineinprolongation of the floor 6.

2| is an idler and discharge pulley tangent to the floor -1, mounted on a supporting frame 22. 23 is an intermediate idler and guide pulley. As the drive pulleys Ilr and I4 are rotated they exert a tension on ythe belt propelling it in the direction of thearrows around the pulleys 23 kand 2| and discharging it into the trough. The water which is fed in through the pipes A9 ows out as indicated by the arrows in Figure 3 around the edges of the belt which terminates short of the walls of the trough, lubricating the belt, the belt being preferably of rubber, which lends itself especially to lubrication by water, the spaces between the belt, the floor and the wearing strips providing adequate passage for the water, whereby `it reaches every part of the under side of the belt. The continuous ilowy of water also prevents the entrance of sand, grit, etc., into the space beneath the belt. y 4

2lil is ya feed spout,l through lwhich sand, or sand and gravel, or coal, or any other material which it is desired to de-water may be discharged. This material engages and travels upon the` inclined guide plate 26, and the inclinedskirt boards 21, and 28. The guide plate 26 is generally keystone shaped. The skirt boards-and the walls 4 and l are cut away to form spillways at 29 and because of the inclination of the skirt boards 2l and 28l and the inclination of the iloor 1, the space lbetween the skirt boards gradually expands in `the direction of the travel of the belt.

As the material is deposited continuously on the centralor adjacent the central axis of the belt, and as that material is propelled through the body of water by the belt, it tends to spread out, being resisted only by the resistance -to now and by the inward trend of water travelling in the direction of thev arrows shown in Figures 3 and 6. This would result in Jamming against the skirt boards and this jamming is prevented by the gradual expansion of the space between them asabove referred to.

drive pulleys I8 and driving pulleys Il as indi- 55 level Ill and along the discharge floor to be ultimately discharged from apparatus over the pulley 2l. belt with its overburden insures the minimum of agitation and results in a smooth, continuous withdrawal and separation from the water of the material carried by the belt.

In the modified form, shown in Figures 44, 5, and 6, there is substituted for the skirt boards, 21 and 28, and guide plate 26, a classifier tank 35. The material to be de-watered is fed to the tank by the feed chute or spout 36. The excess water is discharged through the chute 31. The adjusting screws 38 and hand wheels 39 associated with the columns 4U and the framework 4| make it possible to adjust the classifier tank in the de-watering tank so as to adjust the spaces between the two tanks.

42-42 are fixed guide boards extendingupwardly and outwardly from the trough from immediately above the belt I2, to discharge through the spillway 43. The floor of the classifier tank 35 is formed of two inclined plates 44, generally parallel with the plates 42 so that when the classier tank 35 is raised or lowered with respect to the de-watering tank the width of the sorting column between plates 42 and 44 is increased r decreased thereby limiting the size of the particles of the sorting column.

45 is an angular discharge valve in the bottom of the classifier tank adjustable toward and from the lower edges of the plates 44 by the pull rod 46 and controlled by the hand wheel 41. The water or liquid runs out around this valve 45 into the sorting column. The water level in the olassiiiery tank is above the spillway 43. The water from the classifier tank and from the pipes 9 travels up in the direction indicated by the arrows carrying with it the lighter material, `which material is discharged with the water through the spillway.

The operation is adjustable by adjusting vertically the height of the classifier tank by adjusting vertically with respect to the classifier tank the valve 45 and by controlling the rate of flow of the water through the pipes 9. The material light enough to be supported by the upward flowing current in the sorting column is discharged through the spillway; the heavier material is sorted out and de-watered and treated in the same way as shown in the device in Figures 1, 2 and 3.

The smooth, continuous travel of the In Figure 7, is shown the apparatus which embodies the de-watering device in connection with the vibrating screens, To classify the material, bin 5I is for fine gravel. Bin 52 is for medium gravel, and bin -53 for coarse gravel. Gravel to be classified and de-watered comes to the apparatus on a conveyer belt 54, discharges over thel pulley 55 to a vibrating screen 56. The water is sprayed upon the screen and its burden is discharged through the perforated spray pipes 51. The oversize is discharged from the screen into the coarse gravel bin 53. The undersize is discharged to the de-watering trough 58, of the kind disclosed in Figures l, 2 and 3. This material is conveyed upwardly by the de-Watering belt 59, discharged over pulley to a screen 5| associated with the water pipes 62. The oversize returns to bin 52. The undersize goes to a second de-watering trough 83, being carried upwardly by the belt 64, discharged over the pulley 65, carried over the screen 66, and Water at 61. The oversize on the screen 66 goes to the bin 5I. The undersize, which in this case would preferably besand, would be fed to and treated by\a third de-watering trough 68.

In the modified form-shown in Figure 8, the apparatus in this case is supported upon a dredge scow or barge 80. The de-watering tank 8| is adapted to receive material excavated by the barge, and to be carried upwardly on and dis charged by the de-watering conveyer belt 82. This belt is endless and travels around the pulleys 83, '84 at each end of the trough and is driven by two drive pulleys 85, and 85. The means for driving' them is not here shown. The apparatus is so constructed that the travel of the belt may be reversed, and the belt may travel through the tank as indicated in Figure 8, so that material is discharged over pulley 83 to fill the scow 81. However, the drive movement may be reversed so that it will discharge over pulley 84 toll the'empty scow 88. Under these circumstances, space is not an important factor and the two sides of the drive system merely operates so that each one operates to de-water equally well.

Because the drive is applied to the ingoing end of the belt, as in Figure l, the tension side is outside of the tank. As aresult the belt feeds smoothly and easily along the floor of the tank andno idler pulleysl or guide means other than the supporting rails 8 are needed within the tank. Thus the problem of protecting bearings from abrasions in the tank does not exist.

For the purpose of convenience and to avoid complication I have illustrated in Figure 7 the device of Figures 1, 2 and 3 thereof. Obviously the device of Figures 4, 5 and 6 might equally -well be used.

With reference to the device of Figure 7, it will be noted that in each case of the tanks 58, 63 and 68,- only a relatively small amount of water is used. The gravel or other material brought up by the conveyer 54 is discharged on the screen 56 which is illustrated as a vibrating screen but may be any suitable separating device and the flowing sheet of material passing down that screen is washed by the spray. 'I'he spray Water passes through the screen with the fines into the tank 58 and only enough water `is discharged from the tank through the discharge opening 29 if the device of Figure l is used or through the discharge opening 43 if the device of Figure 6 is used to compensate for the water added by the spray. Whatever dirt is washed off the sand or gravel is thus rapidly withdrawn from the system by the outflow of liquid only.

The material deposited in the tank 58 is thenV discharged by the conveyer 59 in what is at least a partially washed condition through the screen 6I to the tank 63, where it is again washed and the same thing happens with respect to the tank 88, thus the ner the material and the harder it is to wash, the more washings it gets and the dirt washed off in each tank is withdrawn from the system, as distinguished from many types of apparatus hitherto known where the wash water travels through the entire system before being discharged, obviously better washing results because in each tank the washing is accomplished by fresh, clean water.

When the device of Figures 4, 5 and 6 is used in such an assembly as that disclosed in Figure 7, true classification takes place because each tank and screen assembly discharges three products, the screen takes out the oversize, the sorting column takes out the undersize and the belt discharges the intermediate size-the great bulk of the material-to the next stage in the process,

thus a very accurate separation takes place and correct and accurate classification is possible.

ished product. The lighter sand and-water discharging through the chutes 43 will be supplied to the Inext classiiier in the series. Thevsupporting effect of the hydraulic classifying 'column traveling upwardly between the walls I2 and M will be reduced either by reducing the liquid velocity or by changing the distance between the walls, or both, so that the heavier sand in the remaining mass of material will be settled out and carried oi on the belt as a nished product, the sand and water passing up through the classifying column will then be discharged as a nished product or subjected to'a treatment in a third classifier. Attention is especially called to the fact tha the belt upon whichthe` material is supported and by which it is propelled is -a belt in the strict sense of the word as diierentiated from Ichains, ilight conveyers, screw conveyers and the like. It is essential as experience shows in connection withthis device that the belt itself move with the material, that the material be spread in a relatively thin uniform layer upon, be supported by, and carried by the belt. The reason forthis is that if a flight conveyer oranything of that kind is used, the material piles up in front of the nights in a series of separate masses which do not readily drain so that il' an attempt is made to accomplish the same purpose with a ilight conveyer, degradation of the material results and .the material is not effectively dewatered. Moreover since each flight of a iiight conveyer serves as a dam the water draining out must travel around the ends of the dam which causes agitation, cavitation and decreased eillciency.

I claim: A

l. The method of treating comminuted solids which consists in depositing them in a liquid containing feed zone, controllably discharging them therefrom into a liquid containing classiiication zone, there subjecting them to the classifying effect of an upwardly traveling liquid stream, discharging said stream with entrained solids from the system, distributing the solids not entrained by the stream in a relatively thin, narrow sheet and conveying such sheet upwardly along a gradually inclined path emerging from and extending above the liquid level of the classication zone, the velocity of travel being such that agitation of the liquid is substantially prevented, the path extending upwardly above the liquid level for a distance sufiicent to permit entrained liquid to ilow out of and escape from the sheet or solids and then discharging the de-watered solids continuously from the system.

2. A de-watering troughv having an inclined floor extending upwardly above the level o1' the iloor extending upwardly above the level oi! the liquid contained therein. a conveyer belt, means for propelling it upwardly along the door, means forfsupplying material to the trough andl distributing it in a sheet .upon thebelt, andmeans for discharging the de-watered materialk from the belt, spaced wear strips onthe floor of the tank adapted to support the belt, and means for introducing liquid under pressure beneath the belt into .the space between the wear strips and means for discharging the liquid from the trough I at a point above and far removed from the belt. 4. A de-watering trough having an inclined oor extending upwardly above the level of the liquid contained therein, a conveyer belt, means for propelling it upwardly along the iloor, means for supplying vmaterial to the trough and distributing it in a sheet upon the belt, and means for discharging the de-watered material from the belt, 'the supplyingand distributing means ined to contain liquid, means for maintaining the liquid level, thereof, a discharge tank contained within the trough having a discharge below the level of the liquid in the trough and means for' maintaining the liquid level in the tank above the level of the liquid in the trough, means for Isupplying material to be treated to the tank,

means adapted to control the rate of iiow of material from the tank to the trough, means for supplying liquid under pressure to the trough.

and for guiding said liquid in an ascending current past the point of discharge of the tank upwardly to a discharge from the trough, means associated therewith for distributing the material in the trough, the trough having an upwardly inclined floor beneath said distributing means, a conveyer belt adapted to travel alongv said iloor,

yalong a path inclined upwardly from a. point helow the level of the liquid in the trough to a point abovey such level, means for discharging entrained material from the belt at a point the level of the liquid in the trough.

6. In combination a trough having a iioor including two outwardly and upwardly inclined elements, spaced wear strips projecting upwardly from the door, a conveyer belt and means for propelling it along the iioor of the trough along the wear strips, means for supplying material to the trough and guiding and distributing it upon the belt, a discharge pulley at one end of the oor of the trough over which the belt travels, means for forcing water under pressure into the spaces beneath the belt and adjacent the wear strips and means for discharging the liquid from the trough at a peint above and far removed from the'belt.

7. In combination, a liquid containing trough, having an inclined floor extending upwardly above the liquid level, a discharge pulley adjacent and tangent to the edge of the floor, a belt, means for propelling it along the iloor towardsA and 'about the pulley, means for supplying comminuted solids and distributing them in a sheet upon the belt and causing them to travel upwardly along the iioor over the pulley and to be discharged thereabout, wear plates on the iloor supporting the belt, means for supplying liquid under pressure to the space between the iioor and the belt to prevent deposit of solids therebetween and means for discharging the liquid above from the trough at a point above and far removed irom the belt.

8. De-watering means including a tank having an upwardly inclined iioor, means for maintaining a body of liquid in the tank, the liquid level intersecting the floor between its top and bottom, a belt and means for propelling it along the door to emergence above the liquid level, skirt boards within the tank extending downwardly towardV and terminating on a line generally parallel with the belt, the space between the boards increasing in the direction of travel of the belt, means for supplying water to the space beneath the belt and guiding it inwardly across the edge of the belt to prevent excessive discharge of solid material beyond the edges of the belt.

9. A material classifying device including a tank having oppositely inclined walls, a second tank therein having outwardly inclined walls generally parallel with the walls of the rst named tanks,`means for supplying liquid under pressure to the bottom of the first named tank to cause a flow upwardly through the space between the walls of both tanks, means for supplying material to be treated to the upper of the two tanks, means for controlling the rate of flow of the material from said tank into the second one and means for adjusting the size of the space between the walls of the two tanks.

10. A dewatering trough having a bottom comprising a relatively short and sharply inclined ramp, a relatively long and less sharply inclined ramp and a curved ramp joining and tangent to their lower ends, side walls being in liquid tight engagement with the edges of said ramps to form a tank, the longer ramp projecting above the upper edges of the walls, a guide chute in the tank masking the shorter ramp and terminating at its lower end above but adjacent to the curved ramp, means for discharging material to be treated upon the guide chute and causing it to slide downwardly therealong, a continuous endless conveyer belt,.means for propelling it along and in contact with all three ramps throughout substantially their entire length, a discharge roller at the upper end of the long ramp over which the belt travels for discharge of material therefrom, walls extending upwardly along both sides of the longer ramp above the tank Walls and means for controlling the level of the liquid in the tank.

11. A dewatering trough having a bottom comprising two inclined ramps extending upwardly and outwardly in opposite directions, a curved ramp joining and tangent to their lower ends.l

side walls in liquid tight engagement with the ramp to form the tank, one of the ramps extending outwardly and upwardly above the upper edges of the side walls, an endless belt adapted to travel along and in contact with all three ramps throughout substantially their `entire lengths, means outside o! the tank 4for propelling the belt, a roller at the upper end of the ramp and tangent to it about which the belt travels.

12. A dewatering trough having a bottom comprising two inclined ramps extending upwardly and outwardly in opposite directions, side walls in liquid tight engagement with the ramp to form the tank, one of the ramps extending outwardly and upwardly above the upper edges of the side walls, an endless belt adapted to travel along and in contact with the ramps throughout substantially their entire lengths, means outside of the tank for propelling the belt, a roller at the upper end of the ramp and tangent to it about which the belt travels, the belt propelling means being at the end of the tank opposite to the roller, the tight side of the belt extending outside the tank from the roller to the belt propelling means, the slack side of the belt being in the tank.

13. A dewatering trough having a bottom comprising two inclined ramps extending upwardly and outwardly in opposite directions, side walls in liquid tight engagement with the ramp to form the tank, one of the ramps extending outwardly and upwardly above the upper edges of the side walls, an endless belt adapted to travel along and in contact with the ramps throughout substantially their entire'lengths, means outside of the tank for propelling the belt, a roller at the upper end of the ramp and tangent to it about which the belt travels, the belt propelling means being at the end of the tank opposite to the roller, the tight side of the belt extending outside the tank from the roller to the belt propelling means, the slack side of the belt being in the tank, means in the oor of the tank beneath the belt for introducing water under pressure and means at a point removed from the belt for discharging the water from the tank.

RAYMOND W. DULL.

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