WO2003068405A2

WO2003068405A2 - Granular material recovery system

Info

Publication number: WO2003068405A2
Application number: PCT/US2003/004369
Authority: WO
Inventors: Richard R. Ward
Original assignee: Richel, Inc.
Priority date: 2002-02-13
Filing date: 2003-02-12
Publication date: 2003-08-21
Also published as: AU2003213053A1; WO2003068405A3

Abstract

A granular material recovery system for use with a slurry having non-recyclable particles and recyclable particles, the system including a first separator for selectively separating the recyclable particles from the non-recyclable particles, a hopper adapted to receive and accumulate the recyclable particles, a conveyor assembly adapted to selectively transport the recyclable particles from the hopper, and a drying assembly adapted to dry the recyclable particles. A second separator may be provided for further sorting of the recyclable material.

Description

GRANULAR MATERIAL RECOVERY SYSTEM

TECHNICAL FIELD

In general, the present invention relates to a system to recover granular material that when used becomes wet, with a portion ofthe material becoming smaller in size during its normal process of usage, yet which needs to be dry, clean and larger than a specific size for reuse. The present invention can be used in any industry where granular material is used in a fluid a medium and is designed to be recycled by washing, screening, and removing contaminants.

BACKGROUND OF THE INVENTION Many industries use granular material in a fluid a medium such as for sand blasting and the like. In these industries, it is desirable to recover or reclaim that material by washing, reseparating and then drying it for further use. One instance in which granular material may be reclaimed after use is in its use as an abrasive for cutting or other eroding applications. Cleaning and cutting of materials with abrasives entrained in a fluid stream which accelerates the abrasives to erode to different degrees the material it is impinging upon, is a well-known process. If the fluid stream is wet, such as with water as the fluid medium, the dry abrasive introduced into the flow of water will become wet. During the process of impinging the abrasive against the material to be cut or cleaned, a percentage ofthe abrasive or granular material being used will shatter or be eroded reducing its size. As a result, this broken down abrasive material may become unsuitable for reuse. Thus, various methods of recycling the abrasive have been developed.

Typically, once used, the abrasive is discarded in a wet slurry form. Included in the slurry is not only the abrasive granules, but also the eroded particles of the material the abrasive was impinging upon. In known systems, to reclaim the abrasive, the wet slurry is manually dried, and then the abrasive material is screened over a sizing screen to allow smaller particles, unsuitable for further use, to fall through the screen and be discarded. The larger sized particles are retained on top of the screen. These particles may then be washed and cleaned, and on other occasions, the material may be used without washing. Generally, however, most abrasives need to be cleaned and free from dust for reuse and, thus, require washing. Attempts at automation of this procedure have proven labor intensive and cumbersome with several different machines being needed to complete the full process of drying, separating and cleaning the abrasive.

SUMMARY OF THE INVENTION It is therefore an object ofthe present invention to provide an improved system of drying and separating granular material used in a wet application.

It is a further object ofthe present invention to provide a granular material recovery system having a hopper for collecting recyclable material, a conveyor associated with the hopper adapted to selectively transport the recyclable material from the hopper to a dryer assembly adapted to dry the recyclable material or to a separator assembly adapted to sort the collected recyclable material.

Another object ofthe present invention is to provide a conveyer assembly including a conveyor loop having a plurality of voids formed therein to collect material from the hopper in a substantially uniform thickness. Still another object ofthe present invention is to provide a dryer assembly including a heated plate along which the conveyer assembly drags the recyclable material, such that heat transferred from the heated plate dries the particles as they are dragged across the plate.

In general, the present invention generally includes a granular material recovery system for use with a slurry having non-recyclable particles and recyclable particles, the system including a separator for selectively separating the recyclable particles from the non-recyclable particles. A hopper is adapted to receive and accumulate the recyclable particles. A conveyor assembly is adapted to selectively transport the recyclable particles from the hopper. A drying assembly adapted to dry the recyclable particles for reuse. The invention further provides a granular material recovery system for use with wet recyclable material, the system including a hopper adapted to receive and accumulate the recyclable materia. A conveyer assembly is adapted to selectively transport the recyclable material from the hopper. A drying assembly is adapted to dry the recyclable particles for reuse. Means are provided for separating dried recyclable material according to a selected characteristic, the means for separating being located downstream ofthe drying assembly.

The invention further provides a separator in a granular material recovery system.

The separator includes a top screen on which particles and fluid are received, the screen being adapted to move the particles and fluid in a rotary fashion toward its periphery. A spout is provided on the separator and extends outward from the periphery ofthe screen. The spout is divided into a first section and a second section by a divider extending from the periphery of the screen lengthwise down the spout. The first section is located downstream ofthe second section relative to the motion ofthe particles on the top screen. The spout also defines an opening at an end opposite the top screen. The first section of the spout is closed from the opening by an end wall, but the second section of the spout opens into the opening. The invention further provides a separator in a granular material recovery system. At least one screen receives particles and fluid for separation. A vacuum assembly in communication with the separator below at least one ofthe screens is adapted to apply a negative pressure to the separator, whereby the vacuum assembly draws the fluid more rapidly through the at least one ofthe screens.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is front elevational view of a granular material recovery system according to the concepts ofthe present invention with the cover removed to depict details of the system including a vibratory separator having a recycled material discharge connected to a hopper for receiving recyclable material, a conveyor assembly that transports the wet recyclable material from the hopper to a dryer assembly, and a secondary separator for sorting the dried recyclable material exiting the dryer assembly;

Fig. 2 is right side elevational view of the granular material recovery system partially cutaway to depict further details of the secondary separator including a first separator tray having a mesh screen for separating dried granular material received from the dryer assembly, a vibrating motor attached to the first separator tray, a second separator tray located to receive granular material that remains on the mesh screen of the first separator tray, and a pair of guides extending downwardly into a bin to segregate the granular material falling from the first and second separator trays;

Fig. 3 is top plan view of the granular material recovery system depicting a separator having a recyclable material discharge extending over a hopper, where the hopper has a conveyor loop extending through openings on either side ofthe hopper;

Fig. 4 is a view taken substantially along line 4-4 in Fig. 1 depicting the hopper, conveyor assembly, dryer assembly, and secondary separator in greater detail; Fig. 4A is an enlarged view ofthe area circled in Fig. 4 somewhat schematically depicting transport of the granular material from the hopper to the dryer assembly in greater detail;

Fig. 5 is a sectional view taken substantially along line 5-5 in Fig. 2 depicting additional details ofthe dryer assembly and conveyer assembly;

Fig. 6 is a side elevational view of a drying element according to the concepts of the present invention;

Fig. 7 is a bottom plan view of a drying element depicted in Fig. 6;

Fig. 8 is an end view of the drying element depicted in Fig. 7 depicting further details thereof including heating element receivers formed longitudinally in the drying element;

Fig. 9 is a top plan view of a first separator used in conjunction with the present invention depicting a first screen located at the top ofthe first separator on which a slurry of liquid and unseparated granular material is initially received and laterally extending discharge spouts used to remove separated material from the first separator;

Fig. 10 is an elevational view of the first separator depicted in Fig. 9 depicting additional details thereof including an oversized particle discharge spout and container extending radially outward from the top level of the separator, an undersized particle discharge and container extending radially outward from the lowermost level ofthe first separator, and the recyclable material discharge extending from a middle level ofthe first separator;

Fig. 11 is a top plan view of an alternative first separator used in conjunction with an alternative embodiment ofthe present invention depicting a first screen located at the top ofthe first separator on which a slurry of liquid and unseparated granular material is initially received and laterally extending discharge spouts used to remove and dewater separated material from the first separator;

Fig. 12 is an enlarged view of the area encircled in Fig. 12 showing additional details ofthe discharge spout including division ofthe discharge spout into two sections including a first section for capturing the granular material and a second section for discharging fluids from the top screen ofthe first separator; Fig. 13 is an enlarged partially fragmentary side elevational view of a first discharge spout in the first separator partially sectioned to show details of an upwardly sloping floor used to dewater the material before it exits the spout;

Fig. 14 is a front elevational view of an alternative embodiment of a granular material recovery system according to the concepts ofthe present invention;

Fig. 15 is a left side elevational view ofthe alternative granular material recovery system depicted in Fig. 15;

Fig. 16 is an enlarged fragmentary view of a top portion ofthe granular material recovery system depicted in Fig. 14 showing details of a compactor assembly according to the concepts ofthe present invention;

Fig. 17 is an enlarged top perspective view ofthe compactor assembly depicted in Fig. 16; and

Fig. 18 is an enlarged fragmentary front elevational view of a separator assembly depicted in Fig. 14 partially cut away to show details of a second separator assembly having a plough that directs material of different grades to corresponding receptacles.

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the recovery and recycling of granular material. A recycling apparatus is generally indicated by the numeral 10 and may be used in connection with the recycling of a wide variety of granular materials. Thus, the particular materials to be recycled are not considered limiting. For purposes of illustration only, the present invention will be described within the context of an example that involves granular abrasive materials. Therefore, it is to be understood that any reference to abrasives is intended to generally encompass granular materials and the terms will be used interchangeably herein.

It will additionally be understood that any number of applications may require separation based on particle size for purposes of recycling granular material. While the description will proceed with the example of recovering abrasive material from a water jet cutting process, it is to be understood that the present invention is not limited for use in such a process, but may be applied to any number of applications where the reuse of granular material is desirable. In high pressure cutting operations, abrasive may be recovered from a water/abrasive slurry resulting from a high pressure water jet cutting process. In such a process, abrasive entrained within water is directed through a high pressure nozzle to cut through a workpiece made of a material such as wood, ceramics, plastics, metals or the like. The impact ofthe abrasive cuts the workpiece. During this process, the collision of the abrasive granules with the workpiece and with each other results in eroding or shattering ofthe abrasive granules such that they may no longer be of a usable size. On average and depending upon the cutting application, approximately 50% of the original abrasive is recoverable for reuse. Although particle-size measurements are difficult to carry out in a reproducible manner because uniform particles size and shape are rarely achieved in practice, a common description of particle size is by a screen analysis. Standard screens or sieves are made of woven wire that provide essentially square openings. Tyler mesh numbers (W.S. Tyler Co.) are a widely accepted means for describing particle size. Thus, mesh size is often used to segregate reusable abrasive from unusable abrasive material. That is, reusable material may be segregated from oversized or undersized'material through the use of screens, as will be described more completely below.

Returning to the cutting process, typically, abrasive used in cutting is fed into a reservoir and jetted against the workpiece, which is disposed above a sump. The sump collects run-off from the cutting process, including particulate matter such as cuttings from the workpiece, water and the abrasive particles. From this collected material, which will generally be referred to as a slurry, reusable abrasive particles can be separated and reclaimed.

With reference to Fig. 1, recycling apparatus 10 includes a first separator 20 adapted to segregate the abrasive materials within the slurry by mesh size. It will be appreciated that suitable separators are available in the industry and, thus, separator 20 will only be described in general terms; it being understood that any suitable separator may be used in accordance with the concepts of the present invention. By way of example, a conventional vibrating separator 20 is shown in Figs. 9 and 10 and includes a first screen 21, a vibrator 22 and shaker table 23, which provide a mechanical shaking apparatus commonly used in the industry well known to those skilled in the art. In such a separator, the operator adjusts the weights of the shaker table 23 to permit a generally circular agitation.

The slurry is delivered to the separator 20 to begin the separation process. The slurry may be delivered to the separator 20 in any suitable manner including automated and manual means, for example, pumping, pouring, or shoveling the abrasive onto the top screen 21 of first separator 20. The top screen 21 has a selected mesh useful in separating larger particles within the slurry. It will be appreciated that larger particles may clog the top screen 21 resulting in a loss of screen efficiency, and, thus, various means, such as brushes or balls (not shown) may be used to continuously jostle and bump the upper screen to dislodge particles trapped therein.

In the cutting abrasive example, the mesh of top screen 21 is sized to remove oversized particles from the slurry. Smaller particles and fluid are able to pass through the top screen 21 to be discarded or for further separation. The larger particles which do not pass through the top screen 21 are moved by the cooperative shaking ofthe vibrator 22 and shaker table 23 to the periphery 24 of the first separator 20. The abrasive particles are slowly moved by generally circular agitation to the periphery ofthe annular space 25 and under a water wash pipe (not shown), which is disposed around a portion of the periphery 24. The water wash pipe circulates clean water to wash and lubricate the reusable abrasive which accumulates on the perimeter of annular space 25 and which is moved by action ofthe vibrator 22 and shaker table 23 to a discharge spout 28. In this way, at the top screen 21, the oversized particles, collected on the top screen 21, may be washed and removed from the top screen 21 and discharged at an oversized particle discharge spout 28. An oversized particle container 29 may be located beneath spout 28 to collect the oversized particles or these particles may be directed to a general waste container. In the present cutting abrasive example, the oversized particles may include contaminates and particles from the work piece, which may simply be discarded. It is appreciated, however, that the particles gathered on the top screen 21 may be suitable for recycling and, if so, these particles would be collected or further processed as necessary for their reuse. Further separation of the material passing through the top screen 21 may be performed through the use of additional screens or filters. For example, to separate undersized particles or "fines," a second screen 30 may be located beneath the top screen 21 defining an intermediate or middle chamber between the top and second screens 21, 30 within the first separator 20. The undersized particles are able to pass through the second screen 30 leaving the desired sized particles, which will be referred to as recyclable particles R in the present example, on the second screen 30. As with the particles gathered on the top screen 21, the recyclable particles R are radially discharged by the vibratory motion of the first separator 20 and channeled from the separator 20 through a radially extending recyclable discharge spout 31. As desired, the fines may be collected on a filter located near the bottom of the separator 20 and discharged at an undersized particle discharge 33 and collected in an undersized particle container 34. Any liquid within the slurry would pass through the filter and be washed from the separator 20 into a catch basin or waste container, generally indicated by the numeral 35, as by a drain or discharge tube 36 extending from the first separator 20, as shown in Fig. 1. It should be noted that although the first separator, shown by way of example, includes two fixed screens, one skilled in the art will recognize any number of screens, or even a single screen may be used within the purview of the present invention.

It will be appreciated that it is desirable to remove as much water from the particles as possible before they are collected or recycled. As the particles pass the various screens within the separator 20, wash water falls through the screens and drains from the particles until it is collected in the waste container 35. To improve the dewatering ofthe particles, a negative pressure may be applied within the separator 20, as by a vacuum assembly, generally indicated by the numeral 37. In the example shown in Fig. 10, the vacuum assembly generally includes a hose 38 connected to a suitable vacuum source, generally indicated at 39, to create a draw through the separator 20. It will be appreciated that the negative pressure may be applied at generally any point on the separator 20. To draw fluid from the screens, it is believed advantageous to apply negative pressure below one or more of the screens. In the example shown, the vacuum assembly 37 is connected to the top surface ofthe discharge 33. It will further be appreciated that virtually any vacuum source 39 may be used to create the appropriate negative pressure, including, for example, pumps or blowers. The effect of the negative pressure is to draw the wash fluid through the screens 21, 30 more rapidly, such that less fluid is retained in the particles screened by the separator 20. As previously noted, the recyclable particles R are moved from the first separator 20 by way of a recycle spout 31. Recycle spout 31 directs the recyclable particles R to a hopper, generally indicated by the numeral 40 in Fig. 4, where they may accumulate to await drying. To prevent over filling of hopper 40 or clogging ofthe recyclable spout 31 and/or first separator 20, once a suitable level of recyclable particles R is attained within the hopper 40, the first separator 20 may be switched off. The first separator 20 may then be manually reenergized, when suitable fill levels are present in the hopper 40, or an automated switching mechanism may be used. For example, feedback as to the level of material within the hopper 40 may be provided to a process controller, or a timer may be used to automatically return the first separator 20 to an on condition based on a period calculated to create suitable clearance within the hopper 40 for the receipt of additional material.

To allow moisture to escape from the accumulated recyclable material R within the hopper 40, drainage holes may be provided within the walls 41 (Fig. 3) ofthe hopper 40. Moisture draining through the drainage holes may be collected in an overflow down chute 42, which may direct the liquid toward waste container 35. An overflow hose 44 may be attached to the down chute 42 to facilitate transport of the excess moisture to the waste container 35. To transport the recyclable material from the hopper 40, a conveyor assembly, generally indicated by the numeral 50, is provided. As mentioned, the recyclable material R may be held in the hopper 40 until demand arises and, thus, conveyor assembly 50 may be operated intermittently, as such need arises. Alternatively, the conveyor assembly 50 may transport recyclable material R from the hopper 40 in a continuous fashion. Thus, conveyor assembly 50 may be operated manually or by an automated control system. As will be appreciated, a number of conveyor assemblies available in the art may be used to transport the abrasive from the hopper 20 and, thus, the present invention is not limited to the particular embodiment depicted and described herein. In the example shown, conveyor assembly 50 includes a continuous loop, generally indicated by the number 52, directed over a series of guide rollers, generally indicated by the numeral 54, with tension being maintained on the loop by a tensioner, generally indicated by the numeral 55. As shown, the loop 52 may enter the lower portion 56 of hopper 20 through a first opening 57 located at one end of the hopper 40 and exit the hopper at a second opening 58. In this way, loop 52 extends across the entire length ofthe hopper 40 and recyclable abrasive material R within the hopper 40 is deposited on the loop 52 for transport from the hopper 40. Loop 52 rides along a plate 59 beneath hopper 40. Due to the constant movement of the loop 52 over the plate 59, plate 59 may be made removable to facilitate replacement required by wear. As best shown in Fig. 4A, loop 52 may be provided with a plurality of openings or voids 60 within which the recyclable material R is received. For example, loop 52 may be constructed of a network of chain links 61 with the voids 60 being formed between the links 61. As will be appreciated, the weight and vibration ofthe material R above the loop 52, in the abrasive hopper 40, will cause the recyclable material R to fill the voids 60 within the chain loop 52. To ensure a consistent depth of material R on conveyer loop 52, second opening 58 may be in the form of a slot that corresponds to the depth of the thickness of loop 52 yet providing suitable clearance for its passage. In this way, as the loop 52 exits the hopper 40 through slot 58, a substantially even layer of abrasive R is trapped within the voids 60 ofthe loop 52. It will be appreciated that the size ofthe slot 58 may be made adjustable by way of a movable plate or other scraping element, generally indicated by the numeral 56. A variety of scraping elements are commercially available including brushes, squeegees, or simply a plate 65, as shown, and, thus, the invention is not limited to particular type of scraping element used. In the embodiment shown, a plate 65 is provided to adjust the height ofthe slot relative to the loop 52. It is foreseeable that the plate 65 may wear more rapidly than other elements within the hopper 40, as a result of its contact with the material, and thus, plate 65 is made removable such that it may be easily replaced.

In general, the recyclable material R within hopper 40 will remain wet. In most instances, it is desirable to remove moisture from the recyclable material R, and to that end, a dryer assembly, generally indicated by the numeral 70, is located downstream, in terms ofthe path ofthe conveyer loop 52, of hopper 40. It should be appreciated that, in some instances, it may be unnecessary or undesirable to remove the moisture from the recyclable material R. In those instances, the dryer assembly may be inoperative or omitted from the overall recovery apparatus 10. Dryer assembly 70 generally includes a drying element 71 , which transfers heat to the recyclable material R carried by conveyor assembly 50 to cause the moisture within the material R to evaporate. A variety of suitable drying elements 71 are commercially available, for example, radiant heat sources, burners, or electrical resistance heating elements. Each ofthese elements may be incorporated in accordance with the concepts of the present invention.

In the embodiment depicted in Figs. 6-8, dryer element 71 includes a heated plate 72, which defines a plurality of receivers 73 that house electrical resistance heating elements. As best shown in Fig. 8, receivers 73 may be tubular cavities formed within the plate 72. In a manner well known to those skilled in the art, electrical energy is passed through the electrical resistance heating elements (not shown) to generate heat, which is transferred to the surrounding plate 72. The electrical resistance elements may be used in conjunction with any suitable power supply including 110 and 220 volt single phase power supplies, which are widely available for industrial use. The plate 72 is preferably constructed of a conductive material such that heat from the electrical resistance heating elements is readily transferred through the plate 72 and to the recyclable material R, as described in more detail below. Exemplary materials would include metals, such as, copper, steel or aluminum.

To effect drying ofthe recyclable material carried on loop 52, loop 52 passes over the dryer element 71 and may contact the heated plate 72. As shown in Figs. 6 and 7, plate 72 may be provided with a chamfer 74 at one end to force the loop 52 into contact therewith. Once sufficient heat is transferred to the recyclable material R, the moisture within the particles evaporates in the form of steam and rises from the conveyer loop 52. To take advantage ofthe rising heated air and steam emanating from the dryer element and drying material, the dryer assembly 70 may be located beneath the hopper 40, as shown. In this way, heat from the dryer assembly 70 has the secondary effect of heating the hopper 40 raising the temperature ofthe recyclable material R contained therein and potentially drying that material depending on the length of exposure. To reduce heat loss from the apparatus 10, insulating material may at least partially enclose the area surround the hopper 40, conveyer assembly 50 and drying assembly 70. In the embodiment shown, insulating material may conveniently be inserted adjacent the lateral sides ofthese components in the areas indicated by the numeral 67 The drying element 71 may be inclined downwardly from the second opening 58 of hopper 40. In the embodiment shown, drying element 71 extends downwardly and inwardly from a point just outside ofthe second opening 58. To ensure that the recyclable material R is held within the links 61 of loop 52, a guard 68 may extend adjacent to the upstream end 69 of drying element 71 and in close proximity to the loop 52 as it transitions from its path through the hopper 40 downward and inward around roller 54 (Fig. 4A) toward the dryer assembly 70. In this arrangement, as the recycled material R entrapped within the voids of loop 52 dries, the material falls down the incline of the dryer element 71 toward a collection assembly, generally indicated by the numeral 80 and described more completely below. A roller 54 or the tensioner assembly 55 may be located beneath the plane ofthe top surface 76 of plate 72, such that the loop 52 is pulled downward relative to the top surface 76 as it passes the downstream end 77 ofthe plate 52, as best shown in Fig. 4A.

To ensure complete drying ofthe granular material on loop 52, adjustment may be made to the amount of heat generated by drying element 71, as by adjusting the power supplied to electrical resistance elements 73, and/or an adjustment may be made to the rate at which the recyclable material R is carried over the drying element 71. To that end, the conveyor assembly 70 may include a variable speed motor M. It will be appreciated that these adjustments may depend on the type and thickness of material that is carried over the drying element. Advantageously, by using a variable speed motor M, adjustment to the motor speed may be made based on the available power for the dryer element 72. These adjustments would be appreciated by one of ordinary skill and, thus, the present invention is not limited to particular power or rate values. For illustrative purpose only, a heating plate temperature of 600 degrees Fahrenheit and conveyor loop rate of five inches per minute has been found suitable for drying abrasives used in a hydrojet cutting application.

As the moisture exits the material R, it and any dust created during the process may be driven off by a fan, generally indicated by the numeral 78, which may be located on the housing H and communicate externally thereof. Fan 78 may be located at generally any location on housing H suitable for drawing the moisture escaping from the material R. To facilitate operation ofthe fan 78, it may be placed above the drying assembly 70. In the embodiment shown in Fig. 4, a convenient location for the fan 78 is in the open area 79 between the housing H and the hopper 40 above the conveyer assembly 50. As mentioned above, the dried granules that exit the dryer assembly 70 may be collected by a collection assembly 80. Collection assembly 80 may simply include a collection bin 81 into which the dried material falls. However, to perform additional separation or grading of the dried material, a second separator assembly, generally indicated by the numeral 82, may be provided to collect the dried material as it falls from the conveyor assembly 50 at the end of the dryer assembly 70. As in the case of first separator 20, second separator 82 may include multiple screens to separate the dried material into separate grades. For example, as shown in Fig. 4, a first collection tray 83, which is attached to a vibrating motor 84, may be provided with one or more screens to separate the dried material. Material passing through the screen of first tray 83 may then be directed to a first container or area 85 within bin 81 , as by a first chute 86. The material left on the screen of first tray 83 is driven by the vibration ofthe first tray 83 onto a second tray 87 located at the end 88 of first tray 83 and slightly beneath the first tray 83.

Additional screening may take place at the second tray 87, or, the material falling from second tray 87 may be directed to a second area 89 within bin 81 , as by a second chute 90.

An alternative recycling apparatus according to the concepts of the present invention is generally indicated by the numeral 110 and is generally shown in Figs. 14 and 15 of the accompanying drawings. Recycling apparatus 110 is similar to the recycling apparatus 10 and, thus, like numerals will be used to refer to like components as the description proceeds. Recycling apparatus 110 includes a first separator 120 that employs one or more screens to separate abrasive materials within a slurry by mesh size. To begin the separation process, a slurry comprised of abrasive particles in wash water is delivered to the separator 120 in any suitable manner, including automated and manual means. Thus, the abrasive-containing slurry is delivered onto the top screen 121 of separator 120. which provides a generally circular agitation that moves the recyclable materials R to the periphery of the top screen 121. Wash water is provided to help move the oversized particles that will not pass through top screen 121 to a discharge spout 128. One difficulty discovered is that if the top screen 121 has too much material on it, it may not allow efficient processing ofthe recyclable material R and wash water. In such an instance, the top screen 121 may blind, causing the fluids and solids to be discharged at spout 128 without adequate separation or fluid removal. It will be appreciated that it is desirable to remove as much water from the oversized particles as possible before they are delivered to the oversized particle container 129 to reduce the weight of the material within the oversized particle container 129. To that end, spout 128 is designed to more efficiently handle the material on top screen 121 and dewater the material before it is disposed as described more completely below. It will be understood that similar dewatering may be advantageously performed at any screen within the separator 120 and thus, the improved spout design discussed below, may be incorporated at any or all of the spouts within separator 120. In the example depicted in Figs. 11-13, spout 128 is divided into two sections,

128A and 128B. The first spout section 128A is separated from the second spout section 128B by a divider wall 201 that extends from the periphery 124 ofthe top screen 121 to the outlet opening 202 defined by spout 128. An end wall 203 extends from the divider wall 201 to close off section 128 from the outlet opening 202. As shown, end wall 203 may extend generally perpendicularly to the divider wall 201 to close off the first section 128 A from the spout opening 202. Taking advantage ofthe rotary motion ofthe particles, a flap 205 extends from divider wall 201 at the periphery 124 of the top screen 121 to divert particles away from the first section 128 A during normal operation ofthe separator 120. In this way, the particles are generally received in second portion 128B and wash fluid is received in first portion 128 A. The motion of the particles is shown as being clockwise, but a counterclockwise motion may be used. To that end, flap 205 extends in the direction ofthe motion and first section 128 A is generally in a downstream position relative to second portion 128B to facilitate separation ofthe fluid and solid components of the slurry. An opening 206 is defined between the spout 128 and flap 205 to allow runoff of fluid from the top screen 121. First section 128 A defines an overflow outlet 208 that acts as a drain for excess fluid 209 (Fig. 13) on the top screen 121 or second spout section 128B, as will be described below.

With reference to the second spout section 128B , divider wall 201 may be extended beyond the flap 205 to provide a plough portion 210 that diverts particles into the second spout section 128B. The entrance portion 211 of second spout section 128B, which is generally defined between the plough portion 210 and the outer wall 212 of spout 128 adj acent the periphery 124 ofthe top screen 121, may lie generally in the same plane as the top screen 121. To provide for additional dewatering ofthe material entering the second spout section 128B, a ramped section 214 extends outwardly from entrance portion 21 1. As best shown in Fig. 13, the ramped section 214 extends upwardly and outwardly from the entrance portion 211, such that the particles are raised gradually as they move toward the spout opening 202. The ramped section 214 may, as shown, extend upwardly in a linear fashion. A lip 215 extends vertically upwardly from the end ofthe ramped portion 214. The lip 215 causes the oversized particles to build up at the end of second spout section 128B, forcing them to climb over the lip 215 before leaving the spout 128. As the particles climb the incline 214, the fluid within drains from the particles and travels down the incline 214. Further dewatering may occur through an evaporative process. As a result, the oversized particles undergo additional dewatering as they travel up the ramped portion 214 and climb over the lip 215. Eventually the oversized particles exit spout 128 at opening 202, as represented by arrow 216.

As an additional benefit, in the event of flooding of the screen 121, the water and oversized particles must fill the depth (Fig. 13) ofthe second spout section 128B before they could overflow out the spout opening 202. As in the previous embodiment, oversized particles discharged from the spout 128 through opening 202 are collected in an oversized particle container 29 (Fig. 10) or directed to a general waste container. Further separation ofthe material passing through the top screen 121 may be performed through the use of additional screens or filters as described in the previous embodiment.

After recyclable material R leaves the separator 120, it may be collected in a hopper, generally indicated by the numeral 140 to await drying. Drying ofthe recyclable material R may be made in accordance with the previous description, where recyclable material R from the hopper 140 is removed by a conveyor assembly 150 and passed over a drying assembly 170 to cause moisture within the recyclable material R to evaporate. To facilitate use of the conveyor assembly 150, it is desirable to compact the recyclable material R within the hopper 140. To that end, a compacting assembly, generally indicated by the numeral 145, is provided within hopper 140. Compacting assembly 145 generally includes a compacting member 146 that is driven into contact with the material within the hopper 140 by an actuator 147. It will be appreciated that the compacting assembly 145 may take many forms, as such operations are well known in the art. In the example shown, compacting member 146 has the form of a sled having a generally planar main portion 146A and an upturned end 146B. The actuator 147 is a fluid cylinder, which may be hydraulic or pneumatic, pivotally connected to the compacting member 146. Actuator 145 cyclically urges the compactor member 146 into engagement with the recyclable material R to compact it within in the hopper 140. It has been found that an overabundance of recyclable material R within the hopper 140 may cause the conveyer assembly 150 to work inefficiently or become ineffective in transporting the recyclable material R from the hopper 140. Consequently, a limit switch 148 may be provided in connection with the hopper 140 to control the level of recyclable material R therein. It will be appreciated that the limit switch 148 may monitor the level of recyclable material R within the hopper 140 in a number of ways, including vision or mechanical systems. In the example shown, the limit switch 148 interacts with the compacting assembly 145, which rides on the upper surface of the recyclable material R. to deactivate the separator 120 when the hopper 140 has been filled to a selected level. To that end, limit switch 148 is in electrical communication with the separator 120 and includes a switch member 149 that extends to contact the upturned portion 146B of the compacting member 146. As the level of recyclable material R rises, the compacting member is elevated within the hopper 140. Elevation of the compacting member 146 causes the upturned end 146B to move the switch member 149 toward an o f position. As the conveyor assembly 150 removes recyclable material R from the hopper 140, the compacting member 146 falls allowing the switch member 149 to be returned to an on condition reactivating the separator 120 to deliver additional recyclable material R to the hopper 140. It will be appreciated that the switch assembly 148 may be designed for manual reset, such that after turning the separator 120 off, an operator would return the switch to an on condition after a desired amount of recyclable material R had been removed from the hopper 140.

Recyclable material R is removed and dried as described in the previous embodiment. Once dried, the recyclable material R exits the dryer assembly and may be collected by a collection assembly, generally indicated by the numeral 180, which may simply include a collection bin 181 into which the recyclable material R falls. To perform additional separation or grading ofthe recyclable material R, a second separator assembly, generally indicated by the numeral 182, may be provided to separate the recyclable material R as it exits the dryer assembly 170. As described in the previous embodiment, the separator assembly 182 may include multiple screens that separate the recyclable material R into separate grades. Alternatively, or in addition to, the screens as shown in Fig. 18, an air separator assembly, generally indicated by the numeral 220, may be used. In general, air separator assembly 220 includes a blower 222 that directs a stream of air, 224, into the path ofthe falling recyclable material R. The size and weight ofthe particles of recyclable material R causes their path to be influenced to a different extent by the air stream 224. For example, heavier particles R_A are directed downstream to a lesser extent than lighter particles R_B or R_c. Relying on this effect, multiple collection bins 181 may be placed at different locations relative to the air stream 224 to collect particles of varying sized and weight. In the example shown, outlets 225 A, 225B, 225C direct falling particles into bins 181A, 181B, 181C. In this example, heavier particles R_A are collected at 225A, which is located closest to the blower 222, and increasingly lighter particles R_B and R_c are collected at 225B and 225C. It will be appreciated that any number of bins 181 may be used to separate the recyclable material R falling through the air stream 224, as desired.

In light ofthe foregoing, it should thus be evident that upon the granular material recovery system and method ofthe present invention, substantially improves upon the art.

While, in accordance with the patent statutes, only the preferred embodiments of the present invention have been described in detail hereinabove, the present invention is not to be limited thereto or thereby. Rather, the scope of the invention shall include all modifications and variations that fall within the scope of the attached claims.

Claims

What is claimed is: 1. A granular material recovery system for use with a slurry having non-recyclable particles and recyclable particles, the system comprising: a separator for selectively separating the recyclable particles from the non- recyclable particles; a hopper adapted to receive and accumulate the recyclable particles; a conveyor assembly adapted to selectively transport the recyclable particles from the hopper; and a drying assembly adapted to dry the recyclable particles for reuse.

2. The granular material recovery system of claim 1 further comprising a fill switch associated with said hopper and adapted to deenergize said separator when a selected amount of recyclable material is accumulated in said hopper.

3. The granular material recovery system of claim 2, further comprising a timer associated with said switch adapted to selectively reenergize said separator after a selected period of time.

4. The granular material recovery system of claim 2, further comprising a compacting member adapted to contact and compress the recyclable particles within the hopper, wherein said compacting member rides on the recyclable particles, such that when the selected amount of recyclable material is accumulated in said hopper, said compacting member causes said switch to deenergize said separator.

5. The granular material recovery system of claim 4, wherein said switch includes a switch member that extends over said compacting member and is adapted to contact the compacting member when the selected amount of recyclable material is accumulated in said hopper, wherein further elevation of said compacting member urges said lever to an off position, where said separator is deenergized.

6. The granular material recovery system of claim 1 , wherein said conveyor assembly enters said hopper through an entrance slot formed in said hopper and exits said hopper through an exit slot, whereby recyclable material is deposited on to said conveyor assembly as it passes through said hopper.

7. The granular material recovery system of claim 6, wherein said conveyor assembly includes a continuous loop, wherein said continuous loop passes through said slots.

8. The particle recovery system of claim 7, wherein said loop includes a plurality of voids adapted to receive the recyclable material.

9. The granular material recovery system of claim 8, wherein said loop is constructed of chain links.

10. The granular material recovery system of claim 8, wherein said exit slot is adapted to regulate the amount of material carried on said loop.

11. The granular material recovery system of claim 10, wherein said exit slot is sized such that the recyclable material exits said hopper at a generally uniform thickness .

12. The granular material recovery system of claim 11, further comprising a scraper located proximate to said exit slot and in close proximity to said loop, whereby said scraper skims excess recyclable material from said loop to ensure that a generally uniform thickness of material is carried on said loop.

13. The granular material recovery system of claim 12, wherein said scraper is a plate adapted to be adjustably positioned relative to said loop to adjust the thickness of recyclable material exiting the hopper.

14. The granular material recovery system of claim 13, wherein said plate is removable.

15. The granular material recovery system of claim 1, wherein said drying assembly includes a drying element located downstream of said hopper, said conveyor passing in close proximity to said drying element, such that the recyclable material carried by said conveyor assembly is dried as it passes over said drying element.

16. The granular material recovery system of claim 15, wherein said drying element is a heated plate having a plurality of heating elements passing therethrough.

17. The granular material recovery system of claim 15, wherein said dryer element is inclined downwardly toward a collection tray.

18. The granular material recovery system of claim 17, wherein said first collection tray includes a second separator adapted to screen the dried recyclable material, wherein dried recyclable material passing through said screen is channeled to a fi rst recovery chamber and wherein recovery material remaining on said screen is channeled to a second recovery chamber.

19. The granular material recovery system of claim 1, further comprising a second separator located downstream of said drying assembly and adapted to separate the dry recyclable material, said separator assembly including at least one collection tray having a screen on which the dry recyclable material is received, wherein recyclable material that does not pass through said screen is directed to a first bin.

20. The granular material recovery system of claim 19, wherein dried recyclable material passing through said screen is channeled to a second bin.

21. The granular material recovery system of claim 19, wherein dried recyclable material passing through said screen is directed toward an air separator assembly. said air separator assembly including a blower that directs a stream of air across the path ofthe dried recyclable material that passed through said first screen, said air separator assembly further including one or more bins located at selected distances from said blower to collect particles of selected characteristics based on the distance that said particles travel relative to said blower.

22. The granular material recovery system of claim 1 , wherein said separator includes a top screen on which the recyclable material is initially received for separation, said separator being adapted to move particles collected on said top screen in a rotary fashion toward a perimeter of said screen, wherein said separator includes a spout adapted to collect the particles as they are driven from the top screen, said spout including a first portion and a second portion separated from each other by a divider, wherein said first and second portions open toward said top screen. wherein said first portion defines an opening adapted to drain fluid that enters said first portion, and wherein said first portion is adapted to direct granular material accumulated in said second portion toward a material receiving receptacle.

23. The granular material recovery system of claim 22 further comprising, a flap extending from said divider generally in the direction of rotation defined by the separator to partially cover the opening of said first portion.

24. The granular material recovery system of claim 22, wherein said second portion includes a lip extending upwardly from said first portion adjacent said divider, whereby material received in said second portion accumulates to a height corresponding to said lip before exiting said second portion.

25. The granular material recovery system of claim 23 , wherein at least a portion of a floor of said second portion extends upwardly toward said lip, whereby said material in said second portion is elevated as it approaches said lip allowing water to drain from said material before it exits said second portion.

26. A granular material recovery system for use with wet recyclable material, the system comprising: a hopper adapted to receive and accumulate the recyclable material; a conveyer assembly adapted to selectively transport the recyclable material from the hopper; a drying assembly adapted to dry the recyclable particles for reuse; and means for separating dried recyclable material according to a selected characteristic, said means for separating being located downstream of said drying assembly.

27. The granular material recovery system of claim 25, _;wherein said means for separating includes at last one separating tray having a screen adapted to sift the recyclable material based on particle size.

28. The granular material recovery system of claim 25, wherein said means for separating includes an air separator adapted to blow a stream of air across the dried recyclable material leaving the drying assembly, and plural bins located at different distances relative to said air separator, whereby particles of greater weight are directed into the near bin and particles of lesser weight are directed toward the farther bin.

29. The granular material recovery system of claim 25 further comprising means for compacting the recyclable material within the hopper.

30. The granular material recovery system of claim 28, wherein said means for compacting includes a compacting member adapted to contact the recyclable material within the hopper and an actuator adapted to urge said compacting member into engagement with the recyclable material.

31. The granular material recovery system of claim 29, wherein said actuator is a fluid driven cylinder.

32. A separator in a granular material recovery system comprising: a top screen on which particles and fluid are received, said screen being adapted to move said particles and fluid in a rotary fashion toward a periphery of said screen; and a spout extending outward from said periphery having a first section and a second section separated by a divider extending from said periphery lengthwise down said spout, where said first section is located downstream of said second section relative to the motion ofthe particles on said top screen; and wherein said spout defines an opening at an end opposite said top screen, said first section being closed from said opening by an endwall and said second section opening into said opening.

33. The separator of claim 31 further comprising a flap extending from said divider generally in the direction of rotation defined by said top screen and at least partially covering an open end of said first section adjacent said top screen.

34. Separator of claim 32 further comprising, a plough extending from said divider toward said top screen located upstream of said flap, whereby said plough diverts particles toward said second section.

35. The separator of claim 31 , wherein at least a portion of said second section slopes upwardly toward said opening in said spout.

36. The separator of claim 34, wherein said section terminates in an upwardly extending lip, whereby particles must climb said lip before exiting said spout.

37. A separator in a granular material recovery system comprising: at least one screen on which particles and fluid are received for separation; and a vacuum assembly in communication with said separator below at least one of said screens and adapted to apply a negative pressure to the separator, whereby the vacuum assembly draws the fluid more rapidly through said at least one of said screens.

38. A separator of claim 37 further comprising a spout located below at least one of said screens for directing separated particles from out ofthe separator, wherein said vacuum assembly is in communication with said spout.

39. The separator of claim 38, wherein said vacuum assembly includes a hose opening into said spout and connected to a vacuum source.

40. The separator of claim 39, wherein said vacuum source is a blower.