Apparatus for Separation of Material of. Heterogeneous Character

Technical Field This invention .relates to apparatus for separating mater¬ ials of a heterogeneous character, i.e. containing components of different specific gravities and sizes, and more partic¬ ularly for the pre-separation of refuse or similar material containing both heavier and lighter articles or material, as well as smaller and larger articles or materials.

Background of the Invention

A large component of municipal refuse, for instance, may comprise paper products, such as newspaper, cardboard in both flat and carton form, and the like. However, there is also and often in varying proportions, material such as waste metal particles and metal articles, both magnetic and non-magnetic, food waste, dirt or soil and articles or particles of glass and other materials. Due to the variation in the amount of the various types of material, often depending upon the area in which the refuse has been collected, it is quite difficult to find adequate separating devices, since those which may be highly effective are particularly adapted for and therefore essentially limited to the separation of smaller or larger fractions only. Since heavier materials are often intermixed with lighter materials, either or both of which may also vary considerably in size, conventional disc screens and so-called "wobbler" separators having spiral ribs on parallel shafts have been found to be unsuitable for the effective separa¬ tion of refuse into both light and heavy components, as well as different sizes. Thus, heavier components tend to become intermixed with large articles, such as newspapers or cartons, and thereby tend to be carried over the holes through which they are intended to drop. Such equipment is also quite heavy, with relatively heavy drives and substantial inertia

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requiring considerable horsepower to start up in the event of jamming of material between moving parts or complete stop page and hand cleaning operation. Also, trommel screens, to be effective, must be equipped with large screening surfaces and openings of four inches or more in diameter, which re¬ sults in an unduly large proportion of light fractions passi through, thereby substantially reducing the yield of the lig fractions.

U. S. patent No. 2,743,813 discloses a device for separat ing oversized particles from mine run ores having a series of horizontally disposed. , parallel shafts which are hollow and have an elliptical configuration. Each shaft is provide with a series of transverse ribs which follow the transverse contour of the shaft, while the alternate shafts are placed at positions 90° apart from the remaining shafts. The ribs of all of the shafts are in longitudinal alignment, the func tion of the ribs being primarily to guide the material moved by the rotating shafts. U. S. patent No. 1,941,147 disclose a classifying apparatus for ore, coal,stones and the like, which includes a series of horizontally disposed, square, parallel shafts with different types of discs in lateral set These discs include spaced, circular discs mounted in dif¬ ferent off-center positions on the same shaft, but in corres ponding positions on all shafts. In one modification, ellip tical discs are mounted centrally on the shaf s, with alter¬ nate elliptical discs mounted at 90° to the remainder. In another modification, all of the discs are three-sided, with each side being an arc, and are mounted at 60° apart on each shaft. All of the discs on the respective shafts are in lon tudinal alignment with each other. U. S. patent No. 3,028,9 discloses an ore separator having a parallel series of hollo cylindrical rollers with a 90° angular relationship between adjacent rollers and equally spaced elliptical ribs mounted on each roller, with all of the ribs in longitudinal align- ment. Among the objects of the present invention are to pro vide a separator which will handle a relatively large variet of different material, particularly when intermixed; to pro-

ide such a separator which will handle such intermixture of materials which may vary in the proportion of the sizes, as well as lighter or heavier materials; to provide such a separator which will separate the heavy fraction with a mini- mum of loss and secure the highest possible yield of light fractions; to provide such a separator which is particularly adapted to handle refuse; to provide such a separator which may be stopped and restarted with a minimum of horsepower; to provide such a separator which need not be unloaded in order to restart or eliminate a jam caused by a piece of refuse becoming jammed between two moving parts; to provide such a separator, the drive of which may be reversed in di¬ rection,, in order to eliminate a jam; to provide such a sep¬ arator which is adapted to handle relatively large load var- iations; to provide such a separator which is relatively simple in construction and economical to build; and to pro¬ vide such a separator which is efficient and effective in use.

Summary of the Invention

A series of similar non-circular discs are mounted on spaced, parallel shafts in a common plane with the discs of one shaft interspaced with the discs of adjacent shafts. Each disc has a plurality of convex surfaces in equally spaced, radial positions and extending from a shaft or a spacer sur¬ rounding the shaft a greater distance than second surfaces which are interspaced between the first surfaces. A pre¬ ferred contour of the discs is elliptical, although other configurations, such as a three lobe type, may be utilized. The spacing between the shafts is such that, when one end of an elliptical disc reaches a point opposite the periphery of the adjacent shaft or a spacer thereon, only a small clear¬ ance is produced, but when either side of the disc reaches a position opposite an adjacent shaft or spacer thereon, a hole is produced through which smaller components may drop. The holes are alternately opened and closed by the rotation of the discs, which enhances the separation. The shafts are rotated in unison in the same direction, so that the first

surfaces, such as the ends of elliptical discs, will move in a rearward to forward direction above the shaft to propel a bed of material forwardly, such bed being composed of heter¬ ogeneous material containing components of different speci- fie gravities and sizes. The widths of the interspaced disc and/or the distance between the second surfaces, such as the sides of elliptical discs, may vary to decrease or increase the size of the holes at different positions or locations along the path of the bed. Several series, such as three, of shafts and discs with each in an upwardly inclined plane, may overlap with the next forward series, so that the mater¬ ial propelled forwardly by one series will drop downwardly onto the lower end of the next series. A reversal of the components of the bed tends to be produced, so that small particles supported by a paper component having a relatively large area on top of the bed, tends to fall to the bottom of the bed when the paper turns over. Other components, such as cardboard boxes, which may contain much smaller par¬ ticles, tend to be turned upside down in falling from the upper end of one series onto the lower end of the next serie so that the contents of the cardboard box tend to be spilled out and thus fall through the holes. Also, the size of the holes of the three sets of discs may vary, such as to per¬ mit components smaller than aluminum cans to fall through the holes of the first and second sets, and larger compo¬ nents, such as the aluminum cans, to fall through the holes of the third set. Thus, the aluminum cans will be discharge with larger components and obviate difficulties in the attem ted separation of aluminum cans from small pieces of paper, for instance, as by an air stream or jet.

The apparatus of this invention is particularly adapted to be utilized as a pre-separator for the refuse treatment apparatus and method disclosed in the U. S. application of Konrad Ruckstuhl, Serial No. 867,698 filed January 9, 1978 and entitled "Method and Apparatus for Treating Waste Mater¬ ial", now U. S. patent No.

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Brief Description of the Drawings

Additional features and details will become apparent from the description which follows, taken in conjunction with the accompanying drawings, in which: Fig. 1 is a diagrammatic top plan view illustrating gen¬ erally the construction of the separator of this invention. Fig. 2 is a diagrammatic rear elevation of the separator of Fig. 1.

Fig. 3 is a side elevation of the operating discs and associated parts of the separator of Fig. 1.

Fig. 4 is a top plan view of a portion of the separator parts of Fig. 3, on an enlarged scale and illustrating an instantaneous position of certain parts including spaced, parallel shafts rotating in the same direction and non- circular discs mounted thereon.

Fig. 5 is a top plan view similar to Fig. 4, but illus¬ trating the instantaneous position of the parts after rota¬ tion of the shafts through 45°.

Fig. 6 is a top plan view similar to Fig. 4, but illus- trating the instantaneous position of the parts after rota¬ tion of the shafts through 90°.

Fig. 7 is a fragmentary section taken along line 7-7 of Fig. 4 on a further enlarged scale.

Fig. 8 is a fragmentary section similar to Fig. 7, but taken along line 8-8 of Fig. 5.

Fig. 9 is a fragmentary section similar to Fig. 7, but taken along line 9-9 of Fig. 6.

Fig. 10 is a fragmentary section similar to Fig. 7, but illustrating the instantaneous position of the parts after rotation of the shafts through 135°.

Fig. 11 is a fragmentary section similar to Fig. 7, but showing the position of the parts after movement of the shafts through 180°.

Fig. 12 is a side elevation of a disc of Figs. 4-11. Fig. 13 is a fragmentary top plan view showing a portion of the drive mechanism connecting the shafts.

Fig. 14 is a fragmentary top plan view of a construction in which a spacer is placed on the shaft between each adja¬ cent pair of elliptical discs.

Fig. 15 is a cross section taken along line 15-15 of Fig. 10.

Fig. 16 is a side elevation of a disc of Fig. 15.

Fig. 17 is an end elevation of a series of discs which are mounted on the same shaft, but instead of the major axes of the discs being in alignment, the angular relation betwee the axes changes so that a spiral relation is produced to move material also laterally from one side of the separator to the other, as well as longitudinally.

Fig. 18 is a top plan view of the shaft and discs of Fig. 17. Fig. 19 is a fragmentary section similar to Fig. 7 but showing three lobe discs mounted on a series of adjacent shafts.

Preferred Embodiment of the Invention The apparatus, illustrated diagrammatically in Figs. 1 and 2, includes a series of shafts 10 extending in a paralle relation, spaced essentially equally from each other in the same plane, and carrying a series of non-circular discs rep¬ resented by lines 11 and 12 mounted on alternating shafts in different radial positions and extending between side walls 13 and 14. The discs D of the preferred embodiment, as in Fig. 3, are generally elliptical in shape, as will hereinafter appear, although other suitable configurations may be utilized, such as one having a plurality of first convex surfaces in equally spaced, radial positions and having a greater extension from the shaft means than second surfaces interspaced between the first surfaces. In the instantaneous position shown in the top plan view of Fig. 1, the greater length of lines 11 represents the center lines of discs whose longest dimension extends in a horizontal direction,i.e. longitudinally of the apparatus, whereas the lines 12 represent the discs on alternating shafts whose

shortest dimension extends in the horizontal direction and whose longest dimension therefore extends in a transverse or upright direction. As viewed from the end, as in Fig. 2, the longer lines 12 represent discs shown in Fig. 1 as having a greater dimension upright, while the shorter lines 11 rep¬ resent discs whose longer dimension extends horizontally and whose shorter dimension is now seen as upright. When the discs are elliptical, the longer lines of Figs. 1 and 2 correspond to the major axis of the ellipse and the shorter lines to the minor axis. At the front or intake end, a feed apron 15 may be mounted extending at a suitable angle so that the material to be separated may slide down the feed apron onto the discs.

In accordance with this invention, the discs D on one shaft are interspaced with the discs of each adjacent shaft and have substantially the same thickness, so that the discs will rotate with the respective shafts, in turn rotated in a direction to move the discs upwardly from the front toward the rear to move the material from the intake end of feed apron 15 to the opposite or discharge end. In general, as the discs rotate, the material fed onto them will be pro¬ pelled not only forwardly, but also upwardly, so that the various layers and strata of the material will tend to be disturbed and larger pieces of material, such as newspapers, cardboard or the like, will generally be propelled toward the discharge end of the separator, while smaller material will, when reaching the bottom of the bed of material, fall through the holes between the rotating discs, alternately uncovered as the discs rotate. While the forward movement imparted to the bed of material by the discs propels the larger fractions forwardly to the discharge end of the discs, the upward movement imparted to the bed of material will tend to cause smaller components to seek their way down¬ wardly through the bed, for separation by falling through the alternately opened holes. The operation of the discs represented by lines 11 and 12 of Figs. 1 and 2 is also illustrated generally in Fig. 3, in which each set of discs

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D on each shaft is mounted on a pipe 16 which extends throug the spaced discs on that shaft and reduces the size of the aperture uncovered as the discs on the adjacent shafts move upwardly or downwardly past the pipe, between a longitudinal or horizontal and a transverse or upright position. The general movement of the material placed on the discs is in the direction of the arrow 17, i.e. forwardly from the feed apron 15 of Fig. 1, while the direction of discharge of the smaller or fine material is indicated by the arrows 18. The shafts 10 and the discs D along with them, are rotated by a drive mechanism 19, indicated in Figs. 1 and 2. For move¬ ment of the material in the direction of the arrow 17, each shaft 10 is rotated in a clockwise direction, as viewed in Fig. 3. As shown in Figs. 4 and 7, the opposite ends 21 of discs D having the longer dimension in Fig. 4, during rotation, will move upwardly or downwardly, past the pipe 16 on the preceding or succeeding shaft, with a slight clearance, while the clearance between the opposite sides 22 of discs D on alternate shafts and the pipe 16 on the shaft preceding or succeeding such alternate shafts is at a maximum in the transverse or upright position, i.e. at holes 23. It is through these holes that the smaller material falls, in the direction of arrow 18 of Fig. 3, and thereby become separ- ated from the larger material which is propelled forwardly and upwardly by the rotating discs. As in Fig. 4, the shaft may be supported by bearings 24 outside the respective side wall 13 or 14, with the drive train 19 being outside the adjacent bearings. As in Figs. 5 and 8, when the shafts hav rotated through 45° in the direction of arrows 25, holes 23 have begun to open between the discs whose ends 21 were formerly horizontal and the adjacent pipe 16, while the holes 23' between the discs whose ends 21 were formerly upright have begun to close. As in Figs. 6 and 9, when the discs have rotated through 90° from the position of Figs. 4 and 7, they will then be in the opposite position from Figs. 4 and 7, i.e. the discs whose ends 21 were formerly horizontal will now be vertical and the discs whose ends 21 were fc

vertical will now be horizontal. Also, the holes 23 will then be between the sides 22 of the discs whose ends 21 are now vertical and the pipe 16 on each adjacent shaft. As in Fig. 10, when the discs have rotated 135° from the posi- tion of Figs. 4 and 7, i.e. 45° from the position of Figs.

6 and 9, a position opposite to that of Fig. 8 will be reached. Finally, when the discs have rotated 180° from Figs. 4 and 7, as in Fig. 11, the same relative position will be reached, although the underside 22 of a disc formerly on the bottom will now be on the top and the end 21 of a disc formerly on the bottom will now be on the top and the end 21 of a disc formerly beneath will now be on top. As will be evident, during rotation of the discs from the position of Figs 4 and 7, the holes 23 present therein will disappear when the position of Figs. 6 and 9 is reached and an alternate set of holes 23 will appear, while further rotation to the posi¬ tion of Fig. 11 will cause the alternate holes to disappear and holes in the relative position of Figs. 4 and 7 to appear again. It will be noted that, as the discs corresponding to those shown at the center of Fig. 7 rotate from the position of Figs. 4 and 7 to the position of Figs. 6 and 9, the upper end of those discs will move downwardly toward the pipe 16 on the next shaft 10, facilitating the passage of small mater- ial through the hole 23. Of course, the lower end of the center disc of Fig. 7, when moving to the position of Fig. 9, will move upwardly toward the pipe 16 on the previous shaft 10 and will tend to move the material above it upwardly, thereby tending to impel upwardly smaller material above it, although some of the smaller material which has reached the lower portion of the bed of material will slide along the disc until the position of Fig. 11 is reached, when that end of the center disc will move downwardly to open up a hole 23. As illustrated in Fig. 12, the ends 21 of each ellipti¬ cal disc D is arcuate about a shorter radius than the arc¬ uate sides 22. Although any desirable proportion between

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the length and height of the discs may be utilized, as illustrated in Fig. 12, a proportion of two to one has been found desirable in several instances. To accommodate pipe 16, each disc may be provided with a circular, central hole 26, corresponding in diameter to the outer diameter of pipe 16. Discs D may be attached to pipe 16 in any suitable manner, as by spot welding, keying or the like. Also, each pipe 16 may be mounted on a shaft 10 by an annu¬ lar block at each end of the shaft, or the shafts 10 may merely be stub shafts, each extending from an annular attach ment block mounted at an end of a shaft 10. Each shaft or stub shaft extends through a wall 13 or 14 and through a bearing 24, with the shafts or stub shafts on one side,as at wall 13, extending to the drive train 19. As in Fig. 13, the drive train may include a series of chains 28, each of which extends around a pair of inside sprockets 29 mounted on an adjacent pair of shafts 10, and a series of chains 30, each of which extends around a pair of outside sprockets 31 mounted on an alternating adjacent pair of shafts 10. A sprocket on the first shaft may, of course, be driven by a chain which also extends around a sprocket on a shaft of an electric or other driving device. The sprockets are driven so that all of the shafts and the discs along with them, will rotate in the same direction, as by the upper reach of each chain moving in the direction of an arrow 32.

As illustrated in Figs. 14-16, an alternative constructio may comprise a series of discs D' mounted directly on a shaf 10, with a spacer 35 encircling the shaft between each pair of discs. Both the spacers and the discs are preferably cen- tered on the shaft and the spacers have an annular configur¬ ation, as in Fig. 15, as well as a thickness slightly greater than the thickness of the discs, in order to provide lateral clearance for the discs on adjoining shafts. As in Fig. 16, a central hole 36 in each disc D ¹ may be provided with a keyway 37 for attachment of the disc to the shaft. Since the spacers 35 have a circular periphery, the center of which is at the center of the shaft, there is no need to key or

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otherwise attach the spacers to the shaft. As illustrated, the spacers extend outwardly nearly to each side edge 22 of disc D' and are thus particularly useful when the diameter of the circular area between the discs is to be equal to or slightly less than the transverse dimension of the disc. As will be evident, an enlargement of pipe 16 of Figs. 4-11 to approach the side edges 22, for instance, would cause hole 26 of Fig. 12 to be so large that the discs, at the side edges 22, might be so thin that breakage might readily occur. As illustrated in Figs. 17 and 18, the consecutive discs on each shaft may be spaced apart angularly, so as to pro¬ duce a lateral, as well as a forward, movement of the mater¬ ial. This may be particularly desirable when the holes 23 adjacent one side, as adjacent wall 13 or 14, are smaller or larger, the former to limit the size of the material which may drop through, and the latter to increase the size of the material which may drop through. One instance of the latter is when cans, for instance, are mixed with smaller material and are more effectively removed by permitting the smaller material to first drop off, then separating the cans at one side. Such a construction is exemplified by the angular posi¬ tions 41, 42, 43, 44 and 45 of the discs D' on the shaft 10. In the position shown, the difference in angularity between the discs is 15°, although a variation in such difference in angularity may be utilized, such as up to 45°.

An alternative configuration of the discs which may be utilized, when it is desirable to produce a lesser rate of movement of the material from the inlet toward the discharge end, as well as provide smaller holes uncovered by the discs, is illustrated in Fig. 19. Each of the discs D" is illus¬ trated as mounted on a pipe 16 which is supported and ro¬ tated by a shaft 10, although a construction similar to Fig. 16 may be utilized. Discs D" are constructed as essentially three lobe discs, having three convex arcuate projections 47 and three relatively flat sides 48. The apices of the convex, arcuate projections 47, as well as the flat sides 48, are located 120° apart. Also, the convex projections 48

are symmetrical about their center lines. As shown in Fig. 19, a set of discs on one shaft is angularly spaced 60° from the discs on each adjacent shaft, so that the projections 47, as they approach the pipe 16 on either adjacent shaft, will close the space, which will open to its fullest extent when a flat side 48 is directly opposite the pipe 16 on eith adjacent shaft.

In a further construction of this invention, the shafts on which each of three sets of discs are mounted are in parallel relation but disposed in an upwardly inclined plane, as at an angle on the order of 12° to 15°, and overlapping the next set, so that the material falling off the upper dis¬ charge end of the upwardly inclined first set of discs will drop onto the lower end of the second set of discs and, similarly, the material falling off the upper discharge end of the second set of discs will drop onto the lower end of the third set of discs. The impetus given to the bed by the respective discs and the drop to the next set of discs is preferably sufficient that the bed of material will tend to be turned over as it drops from one set of discs to the next. The upper end of each set of discs overlaps the lower end of the next set of discs, respectively, but a slide ex¬ tends downwardly and rearwardly underneath the upper end of the first and second set of discs, so that any material falling through the spaces between the discs of the first and second set of discs, or stages, adjacent the discharge end will move down the slide for discharge, rather than being deposited on the next set of discs.

Such a construction is particularly adapted to be uti- lized when there are objects, such as cardboard boxes or cans carried along with the bed of material moved along by the discs, which objects may have other objects in then, such as small particles of dirt or the like, which would tend to remain in the boxes or cans as the boxes or cans are moved to the discharge end of the apparatus of Fig. 1, for instance. Thus, the tendency of the objects in the bed to turn over as they pass from the first stage discs

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to the second stage discs, as well as from the sedond stage to the third stage discs, insures that the particles carried by the boxes or cans will fall out of them as they turn over. In addition, small particles or objects will move from the top to the bottom of the moving bed, if carried on top of a large object, such as a sheet of newspaper or the like. Thus, in addition to turning over boxes, cans or the like, the tendency of the top of the bed to reverse and becone the bottom when falling over the discharge end of the first and second stages contributes to the facility with which smaller particles and also smaller objects may be separated.

In addition, a variation in the size of the holes or aper¬ tures corresponding to holes 23 of Figs. 4-6 and produced by the discs of the respective stages may be utilized, such as smaller holes produced by the discs of the first stage, while the discs of the second and third stages may produce holes larger in size or increase consecutively. One way in which the difference in holes may be provided, such as smaller holes formed by the first stage discs, intermediate holes formed by the second stage discs and larger holes formed by the third stage discs, is by variation in the length and thickness of the discs of each stage. Thus, the distance between the apices of the ends of each of the first stage discs may be less than the distance between the ends of the second stage discs, in turn less than the distance between the ends of the third stage discs. In other words, the length of the discs may increase from the first stage discs through the third stage discs, such as successive increases on the order of 30% to 35%. The ratio of the length of the respec- tive discs to the width of the discs may be approximately two to one, as before. The spacing between the supporting shafts depends upon the length of the respective discs and the diameter of the spacers for the discs, such as corres¬ ponding to pipe 16 of Figs. 4-11 or spacers 35 of Fig. 15, which, in turn, depends on the desired lengths of the re¬ spective holes produced. To produce square holes, the thick¬ ness of each disc should correspond to the width of the cor¬ responding hole.

In addition to the turning effect- on the components falling from the upper end of one set of discs to the lower. end of the next set of discs, a shaft may be positioned for¬ wardly of and below the last disc of the first stage and carry a pair of oppositely disposed, radially positioned and longitudinally extending blades. Rotation of the shaft in a direction toward the first stage produces a dual effect both insuring the turning effect and causing the blades to impact the falling and turning material, so as to break up articles of glass or similar material sufficiently to permit it to drop through the holes or spaces produced by the sec¬ ond stage discs, rather than being carried on to the third stage discs, even though a substantial proportion of glass may be sufficiently small to fall through the first stage discs. In order to prevent material being impelled rear- wardly of the second stage discs, beneath the slide, an up¬ right stop may be suspended from the underside of the slide and may be conveniently formed of flexible material, such as plastic, to permit it being moved aside to permit access to the discs rearwardly of the stop. A similar...shaft/having blades rotated away from the second stage but at a rela¬ tively slow speed may be provided adjacent the discharge end of the second stage discs, to insure the turning effect and thereby cause dirt or the like to drop out of a carton, for instance.

The difference in the size of the holes may be utilized to cause tin cans or the like to ride over the holes pro¬ duced by the first and second stage discs, which may be pro¬ portioned so as to be smaller than a tin can or aluminum can, but to fall freely through the holes produced by the third stage discs. Thus, smaller articles, including lighter particles, such as paper and the like, will tend to be dis¬ charged through holes produced by the discs prior to the time the tin or aluminum cans are discharged. Those medium sized, light fractions, like paper, can be effectively separated from cans and the heavier fractions by low velocity air sep¬ aration, requiring little air, less power and less filter

back house capacity than other known methods.

In the event that difficulty is encountered with elon¬ gated articles, such as discarded rope, stocking or the like, winding around the pipes 16 of Figs. 4-11 or the spacers 35 of Figs. 14-16, suitable wipers may be installed to en¬ gage the downward moving side of pipe or spacer just below the centerline. Each such wiper may be bowed toward the pipe or spacer, having a width corresponding thereto and be resiliently mounted, as well as being formed of spring mat- erial, if desired. The resilient mounting for each wiper may be supported below the respective pipe or spacer by a transverse bar, pipe, tube or the like which is below the corresponding shaft or shaft means but spaced a sufficient distance from the spacer to provide adequate clearance for the projections of the discs mounted on the shaft means, as they rotate below the spacers.

Although different embodiments of this invention and var¬ iations of particular parts have been illustrated and de¬ scribed, it will be understood that other embodiments may exist and other variations made,all without departing from the spirit and scope of this invention.