US2738068A - Hydraulic classifier comprising a sequence of classifier compartments - Google Patents

Description

March 13, 1956 w. T. MARSTON 2,738,068

HYDRAULIC CLASSIFIER COMPRISING A SEQUENCE OF CLASSIFIER COMPARTMENTS 4 Sheets-Sheet 1 Filed Aug. 2, 1954 $55206 macaw INIENTOR; William T. Murston B1 Alba-lag;

March 13, 1956 w MARSTQN 2,738,068

HYDRAULIC CLASSIFIER COMPRISING A SEQUENCE OF CLASSIFIER COMPARTMENTS 4 Sheets-Sheet 2 Filed Aug. 2, 1954 Sands Discharge Fig. 2.

o INVENTOR William T. Morston March 13, 1956 w. 'r. MARSTON HYDRAULIC CLASSIFIER COMPRISING A SEQUENCE OF CLASSIFIER COMPARTMENTS 4 Sheets-Sheet 3 Filed Aug. 2, 1954 vh Mm INVENTOR. William T. Murston ATTORNEY March 13, 1956 .T. MARSTON 2,733,068

HYDRAULIC CLASSIFIER COMPRISING A SEQUENCE OF CLASSIFIER COMPARTMENTS Filed Aug. 2, 1954 4 Sheets-Sheet 4 0 U \n u I 0 .2 Q

In 'D c U (D l l I I Q I m E 1 .2, I o l 1% g U) I J Q m 9 U U Q U INVENTOR. Q

William T. Marsion ATTORNE I United States Patent HYDRAULIC CLASSIFIER COMPRISING A SE- QUENCE 0F CLASSIFIER COMPARTMENTS William T. Marston, Denver, Colo., assignor to Doro Oliver Incorporated, a corporation of Delaware Application August 2, 1954, Serial No. 447,156

2 Claims. (Cl. 209158) This invention relates to apparatus for hydraulically sizing or classifying a mixture of solids into a sequence of size fractions or groups of sizes, so as to produce in continuous operation at one end of the sequence a group containing a range of the'largest sizes, at the other end of the sequence a group containing a range of the smallest sizes, with any intermediate groups comprising correspondingly graded ranges of intermediate sizes.

This invention had best be characterized by constrasting it with a conventional type of sizing apparatus, namely the one represented by the original Fahrenwald pocket type sizer with multiple spigot discharge of the respective size fractions, and its subsequent improvements (see patents to Haagensen No. 2,371,615, Darby No. 2,410,637 and McKay No. 2,425,551) now in wide use as in metallurgical and other sizing operations.

In such prior conventional sizing apparatus, the aforementioned sequence of size fractions or spigot discharges is derived by passing a continuous supply of the pulp or slurly mixture across a sequence or series of compartments, the so-called sizer pockets, whereby the mixture passing from the influent end of the machine across the top of the pockets through the effluent end of the machine, is subjected to a hindered settling or teeter operation in each respective pocket. The teeter condition in each pocket is maintained by providing in each pocket an upflow of teeter water at a controlled rate, while maintaining an individually controlled pulp density in the teeter bed of each respective compartment or pocket. In this way, there is derived from each spigot a controlled size fraction while the carrier liquid leaves the effiuent end of the apparatus by way of an overflow. Such conventional apparatus is therefore also often termed a multiple spigot discharge sizing apparatus.

In the operation of such known multiple spigot type sizing apparatus the pulp or slurry mixture passes across the top of a respective sizer pocket which represents a pool or column of liquid from the bottom of which rises substantially uniformly distributed a flow of pressure water which is the so-called hydraulic operating water or simply hydraulic water or teeter water. In order to attain a desired size fraction in the teeter bed operation of any respective pocket or compartment, the quantity and upflow rate of this hydraulic water must be controlled and established in relation to other operating factors, namely in relation to the density of the teeter bed to be maintained in that compartment, to the rate of spigot discharge from the bottom of that compartment, and also in relation to the rate of liquid or slurry feed passing into and across that compartment. That is to say, by setting the upflow rate of the hydraulic water and by controlling and maintaining the pulp density of the teeter bed in the respective compartments through the constant control of the discharge from the spigots. This conventional type of sizing apparatus indeed permits relatively sharply controlled classification of the slurry mixture into spigot discharge fractions each of a desired size range. Yet, the character of such a. spigot discharge 2,738,068 Patented Mar. 13, 1956 from such a hindered settling or teeter column depends upon the accuracy of control whereby a desired suitable density is to be automatically maintained in the teeter bed. Devices for such control of the respective spigot discharge are well known and are provided (see the above named patents) in the form of a liftable valve member seated in the spigot dicharge opening at the bottom of each sizer pocket, in conjunction with automatic devices for correctively positioning this valve in such a manner as to compensate for any deviations which might occur from the desired state of density in the teeter bed. Such control devices automatically increase or decrease the rate of spigot discharge correctively in response to changes in density of the teeter bed.

Briefly then, such conventional multiple spigot discharge sizing apparatus comprises a sequence or horizontal row of teeter bed columns, with the feed slurry to be classified entering at one end of that row, to pass sequentially over these columns or pockets while leaving behind in each pocket the respective hydraulically controlled and selectively intercepted settleable size fractions, and a final fraction of fines to escape with the carrier liquid overflowing and discharging from the eflluent end of the apparatus. In this way, the desired solids fractions are abstracted downwardly from the feed mixture, into the respective pockets, thus to be obtained in the form of the respective spigot discharges. In other words, a horizontal stream or horizontally flowing top zone of slurry passes through the apparatus by way of traversing above the respective teeter columns or classifying pockets, whereby the fractions are delivered as respective spigot products from the pockets, the coarsest fraction at the feed or influent inlet and the finest fraction from the spigot at the opposite or eflluent end; of the machine.

This invention has for its object to provide hydraulic sizing apparatus which by comparison with the multiple spigot apparatus just outlined, is of great compactness as Well as of great structural and operational simplicity, and which by comparison requires but a minimum of hydraulic operating water for maintaining the proper sizing conditions in the respective compartments or teeter beds for producing therefrom the desired size fractions.

Another object is to greatly simplify the controls for regulating the sizing conditions of the respective teeter beds and thus regulating the size fractions resulting there from, as by comparison with the automatic spigot discharge controls needed in the operation of the multiple spigot type machine.

These objects are obtained according to this invention by providing a classifier pool subdivided by transverse partitions into a series or sequence of operating compartments, where the transverse partitions extend characteristically from above the pulp level downwardly into the pulp bath to terminate a distance from the bottom in a manner to provide horizontal bottom passages between any two adjoining compartments. In this Way, pulp may migrate in the bottom strata from one cornpartment to the next even while hydraulic teeter operation is in progress in each such compartment. At the same time horizontal bodily vibratory movement is imparted to a member constituting the bottom of the pool.

That is to say, hydraulic water upflows from the bottom of each such compartment at a controlled rate or intensity such as will establish the desired teeter conditions in the respective compartments and thus induce the respective size fractions desired to overflow individually from the respective compartments. Yet, any fraction of solids too large thus to pass ofi by way of the overflow may discharge from the bottom of the last compartment by way of a controllable discharge means or trap device. In other words, with the bottom face vibrating, any particles too large to be passed off hydraulically upwardly through the overflow from the first compartment, will migrate on along the bottom zone into the next compartment there to encounter a greater hydraulic upfiow operating rate so that a corresponding size fraction will be hydraulically raised to and past the overflow of that next compartment, and so on from one compartment to the next in a manner whereby respective size fractions are selectively diverted from the bottom stream or zone upwardly to the respective overflows of the compartments. A last and coarsest fraction of solids may thus reach the last compartment to be discharged therefrom through suitable discharge means or trap means, while the directly preceding fraction discharges from that compartment by way of overflow.

Thus, in the apparatus according to this invention the size fractions are obtained not as underflows but as overflows which are continuous and substantially uniform in character, this in contrast with the more irregular or fluctuating rates at which the automatic density controlled spigot discharges of the earlier machine release the re spective size fractions from the respective spigot discharge devices.

Individual supply and control of hydraulic water for the respective compartments is provided by means of horizontal jet-emitting supply pipes or their functional equivalents, such pipes being mounted at and near the vibratory bottom. A suitable number of jets of hydraulic operating water, suitably disposed, issue from these pipes, the jets being directed at a suitable angle towards the bottom. The combined effect of the jets thus disposed is to produce what may be considered the equivalent of an upflow of operating water through and from the horizontally migrating bottom strata of the pulp, and in substantially uniform distribution across the bottom area of each respective compartment. Means are provided for individually controlling the supply of operating water to the jet-emitting diffuser pipes, so that the teeter conditions in the respective compartments may be individually adjusted to the end of obtaining the desired size fractions therefrom.

It is among the advantages to be gained from the operation of the machine according to this invention, that higher degrees of dilution will not aflect this machine since diluting water will at once be eliminated by overflow from the first pocket. This is in contrast with the above outlined multiple spigot type hydraulic sizing apparatus where all the water must pass through the whole machine with the result that too much dilution in the feed will coarsen the overflow reducing the efliciency of the operation.

As this invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, the present embodiment is therefore illustrative and not restrictive since the scope of the invention is defined by the appended claims rather than by the description preceding them, and all changes that fall within the metes and bounds of the claims, or of forms that are their functional as well as conjointly cooperative equivalents, are therefore intended to be embraced by those claims.

In the drawings,

Figure 1 is a diagrammatic view of a longitudinal sketch of the machine indicating the transverse partitioning and compartmentation of the tank.

Figure 2 is a part sectional side view of the machine structurally more fully implemented.

Figure 3 is a plan view of the machine taken on line 3-3 of Figure 2.

Figure 4 is a cross sectional view taken on line 44 of Figure 2,

Figure 5 is a cross sectional view taken on line 5 5 of Figure 2.

In the diagrammatic view of Figure 1 the vibratory portion of the tank is in the form of a trough structure comprising a bottom 10 and a pair of side walls 11. To allow for vibratory motion this trough structure is suspended as by hangers 12, the vibratory motion being indicated as by double-headed arrow A. The ends of the tank comprise a stationary endwall 13 at the feed inlet end with pulp feed thereto indicated by a feed chute 26, and a stationary end wall 15 at the opposite or coarse fraction discharge end. Both stationary end walls 13 and 15 are connected to the respective associated ends of the vibratory tank portion by means of diaphragms indicated as at 16 and 17 respectively.

A vibrating device 18 is provided for imparting to the tank bottom the desired horizontal vibratory movement. The discharge of the coarse fraction particles takes place through a passage 19 provided between the end wall 15 and the tank bottom 10. The bottom is formed at its outer end with a weir 20 which rises to a point slightly above the upper edge of passage 19, so that the coarse fraction particles may spill over the weir into a stationary receiving chamber 21 formed with the end wall 15. This receiving chamber also represents a clear water column defined by the liquid level L1 or else by the overflow edge E1 of a clear water discharge pipe 22. This receiving chamber is provided with controllable discharge means for the coarse fraction particles as indicated by a valve 23, and is also shown to be provided with an auxiliary water supply connection 24 provided with a control valve 24 for insuring the maintenance of clear water overflow level L1.

Maintaining the clear water overflow level Ll is further predicated upon the presence of a pulp overflow level L2 in the tank, defined by lateral overflow weirs indicated at W1, W2, W3, W4 provided upon at least one of the side walls of the tank.

The differential H between the levels L1 and L2 is the super-elevation of the clear water column in receiving chamber 21 over the pulp column of the body of pulp undergoing classification in the tank. That differential or super-elevation is adjustable as is indicated by removable rings 22 constituting part of the overflow discharge pipe 22. Varying this super-elevation by varying the number of the rings 22 will controllingly alter the density and size separating conditions in the body of pulp in the tank.

The tank is functionally sub-divided into a series of classification compartments C1, C2, C3, C4 by means of corresponding transverse stationary partitions P1, P2, P3 which are connected by means of diaphragms (here not shown) to the respective side walls of the tank. These transverse partitions extend from a point above the pulp level L2 down into the pulp bath terminating a distance above the bottom so as to provide bottom passages p1, p2, 1 between respective classification compartments C1, C2, C3, C4. While all of these compartments are of the same width, it will be noted that the length of each compartment is shorter than that of the preceding compartment. In other Words, if a, b, c, d, designate the respective lengths of these compartments, it will be noted that b is shorter than a, c shorter than b, and d shorter than c.

Operating Water to effect upfiow classification is sup plied at individually controllable rates to each of the classification compartments C1, C2, C3, C4. Means for introducing such operating water at the bottom of each compartment are here diagrammatically shown to comprise for each compartment a horizontal jet-emitting pipe 25*, 25 25, 25 respectively, which pipes are spaced a short distance from the tank bottom, having a vertical feeder pipe 26*, 26", 26, 26 provided with control valve 27 27 27, 27 The vertical feeder pipes in turn have a common horizontal supply header 23.

In Figures 2, 3, 4, 5 this machine is shown as being more fully implemented structurally, namely with respectto tank supporting framework, tank construction,

structural steel members, supply pipe system for operating water, as well as with respect to the mounting of a partitioning system for the tank, defining a sequence of clasliification compartments or classification stages in the tan The machine thus executed comprises as main component portions a framework 29; classifier tank structure T supported and substantially surrounded by the framework 29, which tank structure comprises a movable or vibratable body portion and stationary end portions as well as means for controlling the discharge of coarse fraction solids from the bottom of the tank; a system of transverse stationary partitions 31 functionally subdividing the tank into asequence of classification compartments or stages; and a supply pipe system 32 to provide operating water for therespective classification compartments at individually controllable rates.

These main component portions of the machine will now be described in greater detail:

The basic framework 29 comprises a set of four vertical corner posts in the form of channel irons 33, 34, 35, 36. These corner posts are connected with one another at the top by a pair of transverse tie members 37 and 38, which transverse tie members in turn are interconnected by a pair of longitudinally extending tie members shown in the form of angle irons 39 and 40 at a higher level than an additional pair of horizontally extending longitudinal tie members 41 and 42 also in the form of angle irons, the tie member 41 interconnecting the posts 34 and 35, the tie member 42 interconnecting the posts 33 and 36. The posts 33 and 36 are furthermore interconnected by diagonal tie members 43 and 44 having at their intersecting point a gusset plate 45. Similarly, the posts 34 and are interconnected by diagonal tie members 46 and 47 having at their intersection point a gusset plate '48. The corner posts 33 and 34 are shown to be interconnected by means ofdiagonal brace members 48 and 48 The tank structure 30 comprises a movable trough-like intermediate body portion 49 having a flat horizontal bottom 50 and a pair of side walls 51 and 52. This body portion is suspended from the top of the frame structure 29 within the confines thereof and in a manner to enable it to performlongitudinal horizontal vibratory movement as indicated by a double headed arrow B in Figure 2.

That is to say, the feed inlet end of this vibratable body portion is suspended by means of a pair of hangers 53 and 54 the upper ends of which engage upon brackets 55and 56 respectively, which brackets in turn are rigidly mounted upon the top ends of the corner posts 34 and 35 respectively, the lower ends of the hangers engaging upon the respective ends of a cross bar 57 fastened across the feed inlet ends of the vibratable tank portion 49. The opposite end or coarse fraction discharge end of the vibratable tank portion 49 is suspended from the top of the frame structure 29 by means of a single hanger 58 i the upper end of which engages upon a bracket 59 which is rigidly mounted upon the transverse tie member 38, the lower end of this hanger 58 engaging the central intermediate portion of cross bar 60 fastened across the coarse fraction discharge end of the vibratable tank portion 49.

The tank structure 30 furthermore has a stationary feed inlet end which comprises a stationary end wall plate 61 having marginal connection with the associated end of the vibratory tank portion 49 as by means of a diaphragm member 62. This stationary end plate 61 is provided with a feed chute 63 which has a pair of upstanding bracket members 63 and 63 whereby the feed chute and thus the end plate 61 are rigidly connected to and supported by the transverse tie member 37 of the supporting frame.

The tank structure 3t)further has a stationary coarse fraction discharge end which comprises a stationary end wall 64 the side portions of which are fastened to and supported by the corner posts 35 and 36 respectively, which end wall 64 is connected to the associated end of the vibratory tank portion 49 -by means of a diaphragm member 65. The bottom 59 of the vibratory tank portion 49 extends through a suitably shaped opening 66 in the stationary end wall 64, to provide an outwardly protruding shelf 67 forming with the end plate 64 a discharge passage P of the height in for the coarse fraction material to be delivered from the tank. A submerged weir 68 rises from the outer edge of the shelf 67 to a height hz slightly higher than the height hr of the passage P. A coarse fraction discharge chamber E is provided to receive the coarse fraction solids from passage P spilling over the submerged weir 68, which receiving chamber E is formed by the stationary end plate 64 itself together with a pair of side walls 69 and 70 and an outer end wall 71. The bottom of this receiving chamber E is hopper-shaped namely in the form of an inverted truncated pyramid 72 comprising inclined walls 72 72 72, 72. Coarse fraction material from the bottom of the tank is adapted to spill over the submerged weir 68 into the hopper-shaped bottom '72 whence it may be discharged at a controlled rate as indicated by a discharge connection 73 provided with a control valve 74.

The discharge chamber E is adapted to hold a clear water column defined by an overflow level L3 or else by the overflow edge G of an overflow pipe K. The clear water overflow level Ls has a super-elevation H above the pulp level L4 in the classifier tank, which pulp level in turn is defined by the level of overflow weirs 75, 76, 77, 78 provided in the side wall 51 of the vibrating tank portion 49.

A vibrating device 79 is fixedly attached to the vibrating tank portion 49 at the inlet end thereof, which device comprises a vibrator 80 proper mounted upon the vibratory tank portion by means of a pair of lateral brackets 81 and 82, and a stationary motor 83 driving the vibrator 80 through an endless transmitting element 84 engaging upon a pair of pulleys 85 and 86.

The system of partitions 31 comprises a set of transverse stationary partition walls 87, 88, $9 defining a se ries of classification compartments or classification zones C1, C2, C3, and C4 which compartments are of decreasing lengths. That is to say, the length b of compartment C2 is shorter than the length a of compartment C1, the length c of compartment C3 is shorter than the length b, and the length d of compartment C4 is shorter than the length 0, the effective width W of the tank being the same for all compartments or zones.

Each of the partition walls 87, 88, 89 is adjustably supported from the longitudinal tie members 39 and 40 as by means of a pair of vertical upstanding bracket members or angle irons 96 and 91 unitary with the partition wall, each partition wall being so spaced from the tank bottom as to provide bottom passage p1, pz, 23' between the respective classification compartments. These partition walls have lateral diaphragm connections with the respective side walls 51 and 52 of the vibratable tank portion 49, such lateral diaphragm connections being indicated as at Dr and D2 in Figure 3.

These partition walls are rigidly supported although universally adjustable with respect to the supporting framework, namely adjustable upwardly and downwardly as well as forwardly and backwardly, thus making it possible to vary the vertical extent of the bottom passages pr, p2, p3, as well as to vary the respective lengths a, b, c, d of the respective classification compartments. To this end, each of the vertical bracket members 90 and 91 has a universal slot and bolt connection with its respective supporting member or tie member 39 and 40. This universal connection between the partitioning system and the supporting framework comprises a pair of intersecting slots 92 and 93 extending at right angles to each other with a tightening bo1t94 fastened through the. in

tersect'mg points of these slots fastening the respective bracket members 90 and 91 to their respective supporting members 40 and 39. Forv example, a horizontal slot 92 is provided in the horizontal tie member 40 while a vertical slot 93 is provided in the associated vertical bracket member 90. In this way, a partition may be adjusted forwardly and backwardly within the range X as well as upwardly and downwardly within the range Y.

The pipe system for supplying operating water to the respective classification compartments comprises a horizontal supply header 95 extending above the framework 29 as well as longitudinally and medially of the tank structure 30. Each classification compartment has a pair of sequentially disposed vertical branch supply pipes 96 and 97 extending from the header 95, each vertical branch pipe being provided with a control valve 98. The lower end of each vertical branch pipe connects with a horizontal water emission tube 99* and 99 respectively which tubes are spaced a horizontal distance s (see Figure 2) from the bottom 50. The water emission tubes 99 and 99 have closed ends each being provided along each side with a row of feed emitting holes so disposed as to emit jets 100 of operating water towards the bottom at a suitable angle g below the horizontal. The arrangement of the horizontal tubes 99 and 99 and of the direction of jets relative to the tank bottom are such as to have the operating water in eifect rise from the bottom area in substantially uniform distribution with respect to that area.

The pulp fraction produced in the respective compartments overflow respective weirs 75, 76, 77, 78 into a receiving trough 101 provided along and unitary with the side wall 51 of the tank. The overflow receiving trough 101 which has transverse partitions 102 and 103 and 104 separating the various overflow fractions from one another as Well as discharge spouts 101 102 103 104 for the respective overflow fractions.

The operation of the apparatus may be described by reference to the diagrammatic Figure 1:

With the tank bottom being vibrated horizontally in the directions of double headed arrow A by means of the vibrating device 18, feed pulp containing a wide range of particle sizes from coarse to fine enters the first classification compartment C1 where the rate of supply of operating Water so adjusted by means of the respective control valve 98 that all but a certain fraction of fines is allowed to reach the bottom zone of that compartment, while the fraction of fines overflows with a portion of the liquid across the weir W1 of that compartment. The balance of the mixture of solids in the bottom zone of that compartment migrate to the passage p1 into the bottom zone of the following compartment, such movement or migration in part being due to the vibrating movement of the tank bottom in part to the effect of the hydraulic water, and in part due to hydraulic inducing discharge of the coarsest fraction of solids through bottom opening 19 and spilling over the submerged weir into the receiving chamber 21.

The rate of supply of operating water to the second compartment C2 is so adjusted that the upflowing operating water will selectively lift a next coarser fraction of solids from the mixture of solids in the bottom zone to the top zone in the compartment for overflow and discharge by way of weir W2 of that compartment. From this compartment C2 again the balance of the solids thus remaining in the bottom zone migrate through a bottom passage p2 into the next compartment C3 where again the rate of supply of operating water is adjusted to hydraulically separate and lift a next coarser fraction from the mixture of solids of the bottom zone into the top zone of that compartment and thus to discharge by way of the overflow weir W3 of that compartment.

Again, the balance of the pulp solids thus remaining in the bottom zone of the compartment C3 migrates. through the bottom passage p3 into the last compartment C; where the. supply of operating water is so adjusted as to bydraulically separate a next coarser fraction of the solids from the mixture of solids or pulp in the bottom zone by way of lifting it to and across the overflow weir W4 to discharge, even while the last and very coarsest fraction of the pulp solids, that is the balance of the solids migrates through the bottom passage 19 and across the submerged weir 20 for delivery into the receiving chamber 21 whence it may be removed at a controlled rate through discharge valve 23.

The separation of the various resultant pulp fractions such as received by way of the overflows W1, W2, W3, W4 and the submerged coarse fraction discharge passage 19, is adjusted by the control and coaction of a number of variable operating factors, namely by the control of the operating Water for each classification compartment together with the control of the super-elevation H or level L1 of the clear water column in the receiving chamber 21 over the level L2 of the body of pulp undergoing classification in the tank. The variability of the clear water column in receiving chamber 21 is indicated as by the removable rings 22 at the top of overflow pipe 22. Auxiliary water may be supplied to the receiving chamber 21 through the auxiliary supply pipe 24 and the control valve 24 so that an overflow of clear water is maintained into the overflow pipe 22, insuring the presence of a predetermined liquid level L1 of the clear water column in receiving chamber 21.

A practical example pertaining to the operation of the Figures 1 to 5 embodiment, presents a combination of structural and operational data as follows:

The machine comprises a longitudinal classifying pool about 4 long, about 1 wide, and about 9" deep, with the sands discharge passage at the bottom being about /2 to 2 /2" high and the sands discharge weir about A to 2%" high.

As for the vibrating motion imparted to the bottom of the classifier pool, a practical or suitable operating range for the vibrating stroke under conditions in this example lies in a range of about A2" to about while the stroke frequency covers a practical range of 600 to 1200 reciprocations per minute.

This operating example provides for a stroke length about at a stroke frequency on the order of 900 to 950 reciprocations per minute. In this example, the hydraulic water is supplied by a pair of longitudinally extending horizontal pipes in each classification compartment having a clearance from the bottom of the pool of about /2 with center to center spacing between the pipes of about 6", and the center of each pipe in turn spaced a distance of about 3" from the respective side walls of the pool.

In this example, two jet-emitting pipes are provided parallel to one another in each classification compartment and of /2 standard pipe, having .622 inside diameters and .840 outside diameters. For a typical operation, the first compartment could be 1'-8" long and overflow minus mesh material, the second compartment could be 1-0" long and overflow minus 65 mesh material, the third compartment could be 9" long and overflow minus 48 mesh material, the fourth compartment could be 7" long and overflow minus 35 mesh material. Plus 35 mesh would exit from the bottom drawofl. As an example, the jet-emission pipes in the third compartment would have a spacing between the jet holes of P7 center to center, the jet holes themselves being drill holes produced by a No. 37 drill and having an area each of 0.00849 square inch, the nominal diameter of the drill hole being 0.1040 inch. The first, second and fourth compartments would have similar hole spacing but the jet holes themselves would be smaller progressively through the second and first compartments because of lower water rates used therein and larger in the fourth compartment because of the higher Water rates here. In all compartments, the hydraulic water is emitted from the pipes by jets provided by a double row of. jet orifices in each pipe so disposed that a row of jet openings on each side of each pipe would emit jets of water at an angle of about 20 below the horizontal. The jet emitting pipes extend in the direction of vibration or reciprocation imparted to the bottom of the classification pool. Jet hole sizes as detailed above for the third compartment would give a head loss of about 1 of water column for a flow of about 2.6 gallons per minute. This head loss figure would be adhered to in the other three compartments by varying hole sizes in each compartment to allow for the different water rates necessary therein.

I claim:

1. Apparatus for the hydraulic classification treatment of a pulp containing a mixture of particle sizes ranging from fine to coarse, to effect the separation of the mixture into a fraction of the relatively finest and a fraction of the relatively coarsest size, and also into fractions of at least one intermediate size, which apparatus comprises a horizontal longitudinal tank structure through which pulp is adapted to pass from end to end, said tank structure having at least one transverse partition defining a pair of sizing compartments, said partition terminating downwardly a distance above the bottom to thereby provide a bottom passage and terminating upwardly a distance above the pulp level in the tank, lateral overflow discharge means for each sizing compartment, pulp feeding means for the first compartment, controllable underfiow discharge means forthe last compartment, said tank structure having a horizontal bottom element mounted to perform substantially rectilinear vibratory motion in a horizontal plane, drive means operatively associated with said bottom for imparting thereto said vibratory motion, and individually controllable water supply means for each sizing compartment provided for emitting at the bottom of each compartment operating water at a controlled rate and distributively in a manner whereby the water in cifect rises in substantiall uniform distribution from the bottom, and whereby there is es tablished at the tank bottom a zone of pulp moving from the feed inlet end to the underfiow discharge end, so that by the controlled operation of said underflow discharge and said controllable supply means there are attained by way of overflow size fractions diverted upwardly from said bottom zone of pulp to overflow from the respective sizing compartments.

2. Apparatus according to claim 1, characterized thereby that said tank structure comprises said bottom element together with the side walls of the tank as a vibratory portion, and said transverse partition as a stationary portion, with the addition of flexible diaphragm connections between the side portions of said partition and the respective side walls of the tank structure.

References Cited in the file of this patent UNITED STATES PATENTS 270,492

Claims (1)

1. APPARATUS FOR THE HYDRAULIC CLASSIFICATION TREATMENT OF A PULP CONTAINING A MIXTURE OF PARTICLE SIZES RANGING FROM FINE TO COARSE, TO EFFECT THE SEPARATION OF THE MIXTURE INTO A FRACTION OF THE RELATIVELY FINEST AND A FRACTION OF THE RELATIVELY COARSEST SIZE, AND ALSO INTO FRACTIONS OF AT LEAST ONE INTERMEDIATE SIZE, WHICH APPARATUS COMPRISES A HORIZONTAL LONGITUDINAL TANK STRUCTURE THROUGH WHICH PULP IS ADAPTED TO PASS FROM END TO END, SAID TANK STRUCTURE HAVING AT LEAST ONE TRANSVERSE PARTITION DEFINING A PAIR OF SIZING COMPARTMENTS, SAID PARTITION TERMINATING DOWNWARDLY A DISTANCE ABOVE THE BOTTOM TO THEREBY PROVIDE A BOTTOM PASSAGE AND TERMINATING UPWARDLY A DISTANCE ABOVE THE PULP LEVEL IN THE TANK, LATERAL OVERFLOW DISCHARGE MEANS FOR EACH SIZING COMPARTMENT PULP FEEDING MEANS FOR THE FIRST COMPARTMENT, CONTROLLABLE UNDERFLOW DISCHARGE MEANS FOR THE LAST COMPARTMENT, SAID TANK STRUCTURE HAVING A HORIZONTAL BOTTOM ELEMENT MOUNTED TO PERFORM SUBSTANTIALLY RECTILINEAR VIBRATORY MOTION IN A HORIZONTAL PLANE, DRIVE MEANS OPERATIVELY ASSOCIATED WITH SAID BOTTOM FOR IMPARTING THERETO SAID VIBRATORY MOTION, AND INDIVIDUALLY CONTROLLABLE WATER SUPPLY MEANS FOR EACH SIZING COMPARTMENT PROVIDED FOR EMITTING AT THE BOTTOM OF EACH COMPARTMENT OPERATING WATER AT A BOTTOM OF EACH COMPARTMENT OPERATING WHEREBY THE WATER IN EFFECT RISES IN SUBSTANTIALLY UNIFORM DISTRIBUTION FROM THE BOTTOM. AND WHEREBY THERE IS ESTABLISHED AT THE TANK BOTTOM A ZONE OF PULP MOVING FROM THE FEED INLET END TO THE UNDERFLOW DISCHASRGE END, SO THAT BY THE CONTROLLED OPERATION OF SAID UNDERFLOW DISCHARGE AND SAID CONTROLLABLE SUPPLY MEANS THERE ARE ATTAINED BY WAY OF OVERFLOW SIZE FRACTIONS DIVERTED UPWARDLY FROM SAID BOTTOM ZONE OF PULP TO OVERFLOW FROM THE RESPECTIVE SIZING COMPARTMENTS.

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