US2667881A - Apparatus for draining and washing granular material - Google Patents

Description

F65. 2, 1954 J. E. WATKINS EI'AL 2,667,881

APPARATUS FOR ISLRIAINING AND WASHING GRANULAR MATERIAL Filed July 3,1948 2 Sheets-Sheet 1 INVENTORS 5 Johfi 5. Watkl'ns marten B. mathea/S 1954 J. E. WATKINS ETAL ,88

APPARATUS FOR DRAINING AND WASHING CRANULAR MATERIAL Filed July 3, 1948 2 Sheets-Sheet 2 INVENTORS John E. Watkins martin B. Mathews Patented Feb. 2, 1954 APPARATUS FOR- DRAINING AND WASHING GRANULAR MATERIAL John E. Watkins, Maywood, and Martin B. Mathews, Chicago, 111.

Application July 3, 1948, Serial No. 36,916

9 Claims.

The invention relates to apparatus for recovering from wet granular material the liquid medium with which the material has been treated, and it has particular reference to apparatus for draining and washing granular material after removal from a liquid treating bath.

While not limited to such use, the invention is particularly well suited for operation in carrying out processes of the general type disclosed in our copending application Serial No. 36,915, filed July 3, 1948, now abandoned. In the process disclosed in that application, the granular materials to be separated according to their different specific gravities are immersed in a liquid separating medium of appropriate density and the material which floats and that which sinks in the medium are removed separately therefrom. The materials after removal are usually quite wet, that is to say, a substantial quantity of the liquid separating medium is entrained with the granular material. To reduce the cost of such treatment, it is desirable to recover from the separated materials as much of the liquid separating medium as possible for reuse in the process.

With the above in view, one object of the invention is to provide improved draining and washing apparatus by which substantially all of the liquid separating medium may be recovered liquid separating medium drained from the material and the wash liquor are recovered separately. I

A further object is to provide draining and washing apparatus for wet granular material in which the washing liquid is applied to the material in a novel manner, insuring thorough washing of the material with a minimum (11121111- tity of washing liquid.

Other objects and advantages of the invention will become apparent from the following detailed description of the preferred embodiment illustrated in the accompanying drawings, in which:

Figure 1 is a side elevational view of draining and Washing apparatus embodying the features of the invention, parts of the apparatus being broken away or sectioned to show details of construction.

Fig. 2 is a fragmentary rear view of the apparatus.

Fig. 3 is a partially sectioned side view of one of the buckets constituting a part of the apparatus.

Fig. 4 is a partially sectioned fragmentary front view of the bucket shown in Fig. 3.

Fig. 5 is a side view of the bucket similar to Fig. 3 but sectioned differently to show the interior passages of the bucket.

While the invention is susceptible of various modifications and alternative constructions, we have shown in the drawings and will herein describe in detail the preferred embodiment, but it is to be understood that we do not thereby intend to limit the invention to the specific form disclosed, but intend to cover all modifications and alternative constructions falling within the spirit and scope of the invention as expressed in the appended claims.

Referring to the drawings, the apparatus selected to illustrate the invention is in the general form of an endless conveyor comprising a series of interconnected material holding buckets l0 supported for movement upwardly in a steeply inclined plane and downwardly in another plane. As herein shown, the buckets I 0 are secured at opposite sides on endless bands or chains ll running over upper and lower sprocket wheels l2 and I3. The sprocket wheels are carried respectively on horizontal shafts M and I5 journaled in bearings l6 and I! supported in vertically spaced relation on a suitable frame (not shown). Provision is made for driving one set of sprocket wheels so that the buckets travel upwardly in their upper run as indicated by the arrow in Fig. 1, and downwardly in their lower run.

The buckets I0 are constructed with a particular view to facilitating loading and unloading, to permit introduction of wash water in a novel manner which insures thorough washing of the material therein, and to promote quick draining of the wet material. As the buckets are alike in construction, a description of one will suffice. As shown in Figs. 3 and i, each bucket H3 comprises a generally rectangular outer shell constructed of sheet metal and providing a front 3 wall 20, a back wall 2!, side walls 22 and 23, and a bottom wall 24. The shell thus defines an open top receptacle capable of holding a substantial quantity of granular material.

In the present instance, the side walls 22 and 23 of the shell are formed with generally triangular upwardly projecting extentions 25 and 26, and with similarly shaped forwardly projecting extensions 27 and 28. These extensions overlap or interfit in nesting relation when the buckets are traversing a straight path, thereby forming a continuous shield along the sides of the buckets to prevent objectionable splashing of water on the material being washed.

To obtain the most efficient washing action and to insure flushing of all traces of foreign matter from the material being washed, provision is made for introducing the wash water into the material from the bottom of the bucket for upward flow therethrough; To this end each bucket is provided with an inner bottom member 36 supported in spaced relation to the bottom wall 24 of the outer shell so as to define therewith a Water distributing channel 3: extending over the entire bottom of the bucket. To provide communication between the channel 3! and the interior of the bucket, the member 3!! is made of foraminous material such as screen wire of a mesh such that passage of the granular material therethrough is prevented. Support for the member 39 is provided in this instance by angular brackets 32 fixed to the walls of the bucket.

The channel 3| is arranged to communicate with an upright channel 33 at the rear of the bucket formed by an imperforate back plate 34 spaced inwardly from the back wall 2| of the outer shell, as shownin Fig. 3. The channel 33, in turn, communicates through a lateral opening 35 with a wash water guide mounted on the sidewall 22 of the bucket, as described hereinafter.

To provide for drainage of wash water or other liquid from the material undergoing treatment, the bucket I is provided with an inner front wall 36 of screen wire or the like spaced inwardly from the front wall 2!] and removably supported by angle brackets 31 carried by the side walls 22 and 23 of the shell. The front wall 28 is preferably inclined slightly, as shown in Fig. 3, so that its lower edge is spaced from the forward edge of the bottom wall 2 thus leaving an elongated opening for the discharge of liquid from the bucket. Preferably, an elongated narrow spout '38 is mounted in this opening for directing the discharged liquid into the next adjacent bucket of the series. The wash liquor discharged from one bucket is thus used successively to preliminarily wash the material in succeeding buckets of the series.

The wash water guide above referred to is constructed and arranged to receive water from one or more outlet nozzles 45 past which the bucket is traversed, and to direct a suitable amount of the water into the channel 33 to effect a thorough washing of the material in the bucket. The guide is additionally arranged so that upon movement of the associated bucket out of registration with the nozzle 49, the water discharged therefrom is directed to the guide of the next adjacent bucket. In this way eificient use of all wash water is insured and excessive dilution of the washed out material is avoided.

In the exemplary bucket, the wash water guide comprises a side plate 4i having its forward and top edges shaped similarly tothe side; wall 22 of the bucket and the bottom wall notched as at 42 to provide clearance between the guides of adjacent buckets. The plate 4! is spaced laterally from the wall 22 and together with an extension 43 of the rear wall 2| of the shell and an inclined plate 44 defines a generally triangular upwardly opening chamber connecting with the channel 33 through the opening 35 in the side wall 22. As the bucket passes the nozzle M the water discharged therefrom is received in this chamber and directed into the bucket through the opening Disposed between the wall 22 of the shell and the forward end of the plate 5! in parallel relation thereto is a sheet metal member 45 having a lateral flange 46 at its inner end extending to the wall 22. A transverse member i? extending between the members 4-5 and i! and the adjacent portion of the plate M forms therewith a spout for receiving the flow of water from the nozzle 48 and directing it into the next adjacent guide as the associated bucket passes out of registration with the nozzle. Loss of water by splashing is avoided by dimensioning the spout to fit be- .tween the angular extension 25 of the wall 22 and a corresponding extension 48 of the plate M. Accordingly, all water discharged through the nozzle 4:) is directed into one or another of the buckets Iii as the buckets move past the nozzle.

In the operation of the apparatus, the buckets l 0 are filled while traversing their inner run and the entrained liquid is drained therefrom as the buckets move downwardly. Filling of the buckets is effected through the medium of an inclined chute 5|, fragmentarily shown in Fig. l, positioned to discharge material into the buckets during their passage beneath its lower end. A shield 52 extending from the chute over a plurality of the buckets serves to guide and steady them during the filling operation and eifectually prevents spillage of the material. For guiding the buckets the shield is provided at opposite sides with depending parallel edge portions .320. (Fig. 1) engageable in upwardly opening slots 53 (Fig. 4) in the front walls 28 of the respective buckets.

Washing of the material to remove all traces of the entrained separating liquid is efi'ected in the upward movementof the buckets in their outer run. To facilitate a flow of wash water and wash liquor the buckets Hi are secured to the chains H in closely spaced relation so that they interfit or nest together in traversing the straight portions of their runs. As shown in Fig. 1, the buckets are spaced apart so that the discharge spout 38 of one bucket projects into the next lower bucket of the series. Likewise, the spout portion of the wash water guide projects into the main chamber of the guide for the next lower bucket.

The nozzles 40 are preferably supported so as to supply wash water to the buckets as they approach the upper end of their outer run. In the exemplary apparatus, water is delivered to the nozzles through a pipe 49 under control of valves 49a individual to the respective nozzles. A splash plate 49b overlying .the buckets adjacent the nozzles confines the water to the buckets.

Preferably, the nozzles 40 are located adjacentthe top of the. apparatus so that the wash liquor is enabled to cascade down through a series of buckets before being discharged at the lower end of the run. In this way the entrained liquid is removed progressively as the buckets move upwardly and the material therein receives a final flushing with clear wash water as the buckets pass the uppermost nozzle 40.

To facilitate emptying, the buckets it are secured to the chains II for pivotal movement about a horizontal axis. To this end the buckets are provided at each side with laterally projecting studs 55 (Figs. 2 and 4) engaging in bearings 56 secured to the chains. Provision is made for holding the buckets in upright position at all times except when passing over the upper sprocket whels l2, at which point the buckets are tipped rearwardly to discharge their contents into a hopper 51 (Fig. 1).

Positioning of the buckets is effected by cam bars cooperating with follower rollers 58 carried by a transverse shaft 59 mounted on the back of each bucket. In the exemplary apparatus, straight cam bars 69 (Fig. 1) maintain the buckets upright while traversing their outer run. The cam bars I50 terminate substantially opposite the axis of the upper sprocket wheels i2. Upon further movement of the bucket, the rollers 58 engage curved cam bars 6| which tilt the bucket further to discharge all the material therefrom. The lower portion of the cam bar 6! is shaped to permit the bucket to tilt back toward an upright position as it approaches the chute 5i and straight cam bars 52 act to hold the bucket in such upright position while it is being filled. Additional cam bars 63 serve to tilt the bucket forwardly for initial direct drainage (as distinguished from removal by washing) of any liquid entrained in the material discharged into the bucket from the chute as the bucket moves down through the remainder of its inner run.

Provision is made for collecting the liquid drained from the wet material without dilution so that it may be reused in the separating process immediately without further treatment. The entrained liquid removed by washing is necessarily diluted, but due to the efficient washing action obtained with the construction and arrangement above described, dilution is held to a minimum. To provide for separate collection of the drained liquid and the wash liquor, a tank 65 positioned at the lower end of the bucket assembly is divided by a partitioning wall 58 to provide a drainage sump 6i and a wash liquor sump 68. A shield 69 serves to catch any drippings from the buckets in the outer run and to direct the same into the sump 58. The sumps are provided with suitable outlets 69a and 'I'il through which the collected liquids may be removed as required.

It will be apparent from the foregoing that the invention provides apparatus of a novel and advantageous character for draining and Washing wet granular material. As some of the wetting liquid which was employed in separating out the granular material is collected without dilution by initial direct drainage immediately after its introduction into the buckets H], it is suitable for immediate use without further processing. Moreover, the wetting liquid recovered through washing is diluted only to the extent required to insure its complete removal from the granular material, thus minimizing the cost of concentrating it to usable condition. The high degree of efliciency attained in the washing action is due in part to the novel manner in which the wash water is introduced to the material and in part to the novel arrangements for preventing the diversion of any of the wash water from the material undergoing treatment. In particular, the arrangement whereby the fresh wash water is six introduced into the last material bucket of a series to thoroughly flush any remaining wetting liquid therefrom and thereafter directing such wash liquor successively through the succeeding material buckets of the series contributes to the high operating efficiency of the apparatus.

We claim as our invention:

1. Apparatus for washing granular material including a series of interconnected material carrying buckets movable upwardly in an inclined plane, a water supply nozzle supported adjacent one of the upper buckets of the series, means for traversing the buckets successively past said nozzle, and guide means on each bucket for receiving the water discharged from said nozzle, said guide means being alined in superposed relation as said buckets move along the inclined plane, each of said guide means having communication with the interior of its associated bucket and including a member operative initially to direct the received water into its associated bucket and upon further movement of that bucket with respect to said nozzle to direct the water into the guide means of the next adjacent bucket.

2. Apparatus for washing granular material including a series of interconnected material carrying buckets movable upwardly in an inclined plane, a water supply nozzle supported adjacent one of the upper buckets of the series, means for traversing the buckets successively past said nozzle, and guide means on each bucket for receiving the water discharged from said nozzle operative to direct it into the associated bucket when that bucket is substantially alined with the nozzle, each of said guide means including a spout portion extending into overlying relation with the guide means of the next adjacent bucket to provide a channel for directing the Water to such adjacent bucket as one bucket moves out of alinement with the nozzle.

3. Apparatus of the class described including a series of interconnected upwardly opening buckets supported for movement in an inclined plane, means for filling the buckets while in mo- J tion including an inclined chute, means for moving the buckets successively past said chute, and a guard extending from the end of said chute over a plurality of the buckets to prevent spillage of material delivered from said chute, said guard having depending parallel flanges engaging in slots in the walls of the buckets to guide the buckets while in filling position adjacent said chute.

4. In apparatus of the class described, in combination, a material holding bucket including a sheet metal shell having front, back, side and bottom walls, means for introducing wash water to the material from the bottom of the bucket including a perforated member supported in spaced relation to the bottom wall of the shell, an imperforate inner member supported in spaced relation to the back wall of the shell, said members and the adjacent walls of the shell defining channels for directing a flow of wash water to the material in the bucket, and a perforated inner member supported in spaced relation to the front wall of said shell, said shell having an outlet opening forwardly of said last-mentioned member for the discharge of wash water passing through said last-mentioned member.

5. In apparatus of the class described, in combination, a material holding bucket including a sheet metal shell having front, back, side and bottom walls, means for introducing wash water to the material from the bottom of the bucket including a perforated -member supported in spaced relation to the bottom wall, of the shell, an imperforate inner member supported in spaced relation to the back wall of the shell, said members and the adjacent walls of the shell defining channels for directing-a flow of wash water to the material in the bucket, said shell having an opening at its lower end for the discharge of wash water, and a perforated member operative to prevent the passage of the material through said opening while permitting the'fiow of wash water therethrough.

6. In apparatus of the class described, in combination, a material holding bucket includinga sheet metal shell having front, back, side and bottom walls, means for introducing wash water to the material from the bottom of the bucket including a perforated member supported in spaced relation to the bottom wall of the shell, an imperforateinner member supported in spaced relation to the back wall of the shell, said members and the adjacent walls of the shell defining channels for directing a flow of wash water to the material in the bucket, said shell having an opening at its lower end for the discharge of wash water, means for preventing the passage of the material through said opening with the wash water, and a spout adjacent said opening for directing the flow of wash water discharged therethrough.

7. In apparatus of the class described, in combination, a plurality of material holding buckets each including a sheet metal shell having front, back, side and bottom walls, upwardly projecting extensions on the side walls of said shell, forwardly projecting extensions on the side walls of said shell adjacent the lower ends thereof, the forwardly projecting extensions of one shell being operative to nest with the upwardly projecting extensions of the next adjacent shell to form a continuous shield extending along the sides of the buckets.

8. In apparatus of the class described, in combination, a plurality of material holding buckets each including a sheet metal shell having front, back, side and bottom walls, inner walls in said shell defining wash water channels extending along the back and bottom walls of the shell, the channel at the bottom of the shell communicating with the interior of the shell for directing a flow of water upwardly through the material in said shell, and an outlet for the water at the front of said shell comprising a generally rectangular spoutextending transversely across the bucket and having its upper-end located above the inner bottom wall and its-lower end projecting substantially below the bottom wall of the shell. 9. Apparatus for washing granular material including a plurality of material carrying buckets interconnected in an endless series and supported for movement in a closed path a part of which is generally upright, a liquid supply nozzle supported adjacent the upper end of the upright part of said path, means for traversing said buckets successively past said nozzle, and means on each bucket defining a chamber portion and. a spout portion positioned for receiving successively the liquid discharged from said nozzle as the bucket moves past the nozzle, said chamber portion communicating with the interior of said bucket, and said spout portion alining with the chamber portion of the bucket next below in, the series to direct thereceived liquid thereto.

JOHN E. WATKINS. MARTIN B. MATHEWS.

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