This invention relates generally to systems and methods for separating materials, such as those that compose disposable diapers.
In the process of diaper manufacturing, there are often defects in the diapers produced, which prevent the diaper manufacturers from selling their product. The defective diapers, as a rule, are unmarketable and ultimately increase the cost of production due to the loss of valuable raw material. Thus, diaper manufacturers rely on recovery or reclamation of the diaper material to make up for at least a portion of the financial loss. This loss is prevalent in the manufacture of diapers of various sizes (such as newborn, toddler, and adult diapers) and colors.
Diaper manufacturers generally bale the defective diapers to be sent to facilities where the materials can be reclaimed. Often, diaper manufacturers pre-shred the diapers coarsely to prevent them from being sold by others. Diaper manufacturers also often process the diapers once to reclaim at least some of the readily accessible cellulose and super-absorbent polymer (SAP), also known as fluff. However, the bales that are sent to reclamation facilities still contain significant amounts of fluff. The diaper material can further comprise high density polyethylene (HDPE) film, non-woven polypropylene (PP), SPL rubber (such as is found in the waist band of diapers), SAP/fluff, print, colorant, additives, and the like.
Current diaper reclaim systems are unable to effectively separate the fluff from the plastic materials in the disposable diapers. Thus, the byproducts of currently known systems are not sufficiently pure for further use in other systems that use the reclaimed products.
Thus, there is a need in the art for systems and methods for efficiently separating diaper materials to achieve high purity levels in the separated materials so that they can thereafter be recycled or reused.
In accordance with the purposes of this invention, as embodied and broadly described herein, this invention, in one aspect, relates to systems for separating materials, such as, but not limited to, materials that compose disposable diapers. In one aspect, the system comprises one or more separator units, each comprising an inlet for receiving the materials, means for separating the materials, and a plurality of outlets for each of the materials that are being separated.
In another aspect, the system comprises one or more of the following: means for shredding the material prior to separating it, means for baling the separated material, means for drawing or driving air through at least a portion of the system, and means for filtering the air being drawn or driven through at least a portion of the system.
In another aspect, the invention relates to methods for separating materials. In one aspect, the method comprises providing at least two materials to a separator unit comprising an inlet configured for receiving the at least two materials, means for separating the materials from each other, a first outlet for a first material and a second outlet for the second material.
Additional advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate (one) several embodiment(s) of the invention and together with the description, serve to explain the principles of the invention.
The present invention may be understood more readily by reference to the following detailed description, examples, drawings, and claims, and their previous and following description. However, before the present devices, systems, and/or methods are disclosed and described, it is to be understood that this invention is not limited to the specific devices, systems, and/or methods disclosed unless otherwise specified, as such can, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular aspects only and is not intended to be limiting.
As used in the specification and the appended claims, the singular forms “a,” “an” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to a “separator unit” can include two or more such separator units unless the context indicates otherwise.
Ranges may be expressed herein as from “about” one particular value, and/or to “about” another particular value. When such a range is expressed, another aspect includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms another aspect. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint.
As used herein, the terms “optional” or “optionally” mean that the subsequently described event or circumstance may or may not occur, and that the description includes instances where said event or circumstance occurs and instances where it does not.
Reference will now be made in detail to the present preferred embodiment(s) of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used throughout the drawings to refer to the same or like parts.
In one aspect of the present invention, a system is provided for separating at least two materials, such as, but not limited to, those materials found in disposable diapers. As previously described, disposable diapers typically comprise cellulose and super-absorbent polymer (SAP), together commonly known as fluff, as well as HDPE film, non-woven PP, SPL rubber, print, colorant, additives, and the like. For simplicity of description, but not intending to be limiting, the materials can generally be categorized as fluff and plastic. However, it is to be appreciated that the materials can comprise more or less than fluff and plastic, or can comprise other components.
As described above, the disposable diapers or diaper material is typically received by a reclamation facility in the form of a bale that is baled with wire or straps. The bale is then received by the system for processing, such as described in various aspects below. In one aspect, the diaper material is loaded onto a conveyor. If baled, the straps are cut and the bales are conveyed to a de-baler. The de-baler can contain conventional means for holding the bale in position while the diaper material is chipped away from the constrained bale. With reference to
The shredded material is then conveyed to one or more separator units 110. According to one aspect, each separator unit comprises an inlet for receiving the input materials and means for substantially separating a first of the materials (such as, but not limited to, fluff) from a second of the materials (such as, but not limited to, plastic). Each separator unit also comprises a first outlet for the first material and a second outlet for the second material. Thus, in one aspect, fluff is passed through the first outlet and plastic is passed through the second outlet. The system also comprises means for baling the first material, such as fluff, in operative communication with the first outlet, and means for baling the second material the second material, such as plastic, in operative communication with the second outlet. Thus, if the two materials are fluff and plastic, the system comprises a fluff baler 124 and a plastic baler 122. In some aspects, the separator unit(s) 110 may separate some, but not all, of the fluff from the plastic. In this aspect, the system can also comprise a final separator 120 configured to further separate the plastic and fluff received from the separator unit(s).
In a preferred aspect, the system primarily relies on air for the separation of the materials and moving the materials to and through the various system components. Accordingly, in one aspect, the system comprises a condenser 130 that is configured, in part, to filter air and remove fluff particles from the air being driven or drawn through the system. The condenser is in operative communication with the first outlet of the primary separator unit(s), and comprises an outlet in operative communication with the fluff baler. The system, in some aspects, further comprises a system air filter 140 configured for filtering the air being driven or drawn through the system and releasing the filtered air to the ambient environment. The system may also include one or more fans (described in greater detail below) for drawing or driving materials through the system. For example, with reference to
As described above, in one aspect, the system comprises a shredder 102 configured for shredding the diaper materials that is in operative communication with the inlet of the separator unit(s) 110. The shredder may be any commercially available shredder, such as the RG62 HiTorc™ shredder, available from Vecoplan, LLC (High Point, N.C.). The shredder can also control or meter the material being conveyed to the separator unit(s).
In other aspects, the system comprises a secondary shredder 104 or chop fan that is configured to shred or chop the diaper material into finer pieces, such as is shown in
In one aspect, the system comprises at least one separator unit that comprises an inlet for receiving the diaper material (such as from the primary shredder 102 or secondary shredder 104). The separator unit also comprises means for separating a first material from a second material, such as separating fluff from plastic. Each of the at least one separator unit also comprises a first outlet for the first material and a second outlet for the second material. Each separator unit comprises a housing and a separation cone positioned within the housing and defining a space between the separation cone and housing for separating the first and second material. A separator unit such as a Model FS400 separator from Ibis International (Hoschton, Ga.), can be used as a suitable separator unit.
With reference to
Referring to
Optionally, air can be driven into the separation cone so as to drive the fluff through the aperture(s) to the space between the separation cone and the housing, while retaining the plastic within the separation cone. It is contemplated that a vacuum source and means for driving air into the separator unit can be simultaneously applied to the separator unit. A scrap fan, such as the I.E. 11-19-B fan (available from American Fan Company/Woods USA, Fairfield, Ohio), can be used to draw (such as in a vacuum manner) or drive air into the separator unit. Optionally, the system comprises a main system fan (such as system fan 150 shown in
With reference to
In one aspect, the system comprises a series of two or more separator units. The system, in one aspect, comprises from about 2 to about 15 units. Optionally, the system comprises from about 5 to about 10 units. In a particular aspect, the system comprises 8 separator units. In such aspect, the system may comprise separator units 114 all having a substantially cylindrical shape, separator units 116 all having an inverse frustoconical upper portion and cylindrical lower portion, or a combination of both in any order. For example, in a particular aspect, the system comprises a series of four separator units having cylindrical separation cones followed by a series of four separator units having frustoconical and cylindrical separation cones.
If two or more separator units are used, the inlet of the first separator unit, such as shown in
As described above, the fluff separated from plastic in each of the separator units is passed through a first outlet of each separator unit. In one aspect, each of the first outlets is in operative communication with a fluff baler. Optionally, the fluff is first passed to a condenser 130. The first outlets may be in operative communication with the condenser via a common conduit or conveyor, or via separate conduits or conveyors. In one aspect, a first series of four separator units may have first outlets all in operative communication with a first conduit, and a second series of four separator units may have first outlets all in operative communication with a second conduit. Fans may be used to blow or drive the fluff through the conduit(s). Fans, such as the I.E. 26-MH fan of American Fan Company/Woods USA (Fairfield, Ohio), are suitable for this purpose.
The condenser comprises an inlet configured for receiving the fluff from the one or more conduits or conveyors. With reference to
Optionally, or in addition to the pressure control described above, the condenser may comprise means for maintaining a uniform, predetermined thickness of the mat. The predetermined thickness can range from a substantially negligent amount of fluff, to several millimeters or inches thick. For instance, the condenser may comprise a solid roller 135 configured to compress the mat against the drum surface. A doffing roller 134 may be positioned in operative relation to the solid roller and may be configured to maintain the predetermined mat thickness by doffing off the excess fluff. In this aspect, the drum is configured to rotate about an axis substantially parallel to the longitudinal axis of the condenser (indicated by the curved arrow in
As discussed above, all or some of the fluff passing through the condenser will be passed via the first condenser outlet to the fluff baler 124. The condenser also comprises a second condenser outlet in communication with the inner portion of the drum 132 configured for the passage of air. The air will be driven or drawn to the air filter 140, described further herein below. A suitable condenser is the 72×54 FAF 11 Style 3 condenser, available from Continental Conveyor and Equipment Company (Winfield, Ala.).
In various aspects, fluff passes from the primary separator unit(s) to the fluff baler 124. In other aspects, the fluff passes from the primary separator unit(s) to the condenser, and then to the fluff baler. The baler is configured to bale the fluff, such as for sale on the secondary market. A suitable baler may be a horizontal baler, such as the HL-12-X-HDM baler available from Harris Waste Management Group, Inc. (Peachtree City, Ga.). As may be appreciated, fluff bales or plastic bales and mini-bales (described below) can be wrapped (e.g., stretch wrapped, shrink wrapped, etc.) in a conventional manner, such as by using the H206-072-1138 AV bale wrapper from Highlight Industries (Grand Rapids, Mich.).
As described above, plastic (and any additional fluff) passes through the second outlet of each separator unit. In one aspect and as illustrated in
In various aspects, plastic passes from the second outlet of the final separator unit of the series of primary separator units 110 to a desired or selected plastic baler 122. Optionally, the plastic passes through a final separator 120 for additional fluff/plastic separation, and is thereafter passed to the plastic baler. In one aspect, a mini-baler may be used for creating mini-bales that are used in the production of reusable plastic pellets, as described in U.S. patent application Ser. No. 11/466,040 entitled “System and Method for Recycling Using Waste Stream Products”, filed Aug. 21, 2006, which is incorporated in its entirety herein by reference. A suitable mini-baler is the HRB-14N 40 HP mini-baler available from Harris Waste Management Group, Inc. (Peachtree City, Ga.).
As described above, in various aspects, the system of the present invention is substantially a pneumatic system. Air may be driven or drawn through the system via one or more fans, such as system fan 150, which is configured to draw air through some or all of the system components. With reference to
In one aspect, the system comprises an air filter 140 for filtering the air being driven and/or drawn through the system. The air filter in one aspect comprises a drum. The drum may be substantially large, having a length in the range of about 100 to 200 inches, and a diameter of 50 to 100 inches. In one particular aspect, the drum is approximately 163-164 inches in length and about 83 inches in diameter. In another aspect, the drum is approximately 95 inches in diameter. The drum may be sized for approximately 32,000 to 40,000 CFM, 100 to 150 FPM. In one aspect, the drum comprises a metal mesh covered with a filter media “blanket”. A suitable drum filter is the Model 7-6 filter of Ibis International. The drum is in operative communication with a vacuum source (such as, but not limited to, Fan #4 or system fan 150) such that the “blanket” surface is adapted to pull fine dust from the condenser 130 and other system components.
In operation, the drum rotates and a series of fixed nozzles is activated via a diverter valve to pull material off of the drum surface and into a nozzle fan which sends the dust to a cartridge collector for final collection and disposal into a waste container. Optionally, any additional fluff particles pulled off of the drum surface can be fed back to the condenser and processed as described above. Material sent to the cartridge collector is collected on a fiber or paper cartridge, which is periodically pulse cleaned using compressed air from the clean air side of the cartridge collector. Material dropping off of the contaminated side of the cartridge due to the pulse cleaning drops through a rotary airlock into a collection container.
Any remaining particulate matter in the air that has passed through the drum filter “blanket” is captured on secondary filtration cartridges, which are periodically pulse cleaned from the clean air side of the drum filter. The material which is removed from the contaminated side of the series of secondary filtration cartridges drops onto the floor of the secondary filtration chamber for later removal. Finally, air passing through the series of air filters (e.g., the drum and filter cartridges) is drawn by the system fan 150 to the ambient environment. It is contemplated that this air is 99.5% (or higher) particulate-free down to 0.4 microns. The system fan may be operated by a variable speed drive so that it can be adjusted to accommodate the current parameters or state of the system.
As may be appreciated, the system according to various aspects of the present invention may comprise additional components or instrumentation, such that the system can be controlled partially or fully automatically. For example, sensors may be installed on or within various system components: optical sensors within the duct work or conduits (such as to monitor for jams or clogs); optical sensors on the fiber baler and plastic baler; and pressure sensors or instrumentation on each separator unit. It is contemplated that each system component can be controlled manually, automatically, or a combination of both. For example, logic can be implemented to control each component individually or in combination with other system components. As an example, logic may be implemented to increase or decrease pressure within the separator unit(s) in the case of a material jam or clog, or to modulate the flow of material between potions of the system components.
Other components may be used to maintain stable functionality of the system. For example, clean outs can be installed in the separator units and/or the ducts and conduits of the system to allow for easy removal of clogs or jams. In this aspect, the clean outs can be placed in such a way that the system need not be fully or partially shut down in the case of a jam or clog.
In one aspect, a method is provided for separating materials, such as those found in disposable diapers. In one aspect, a system substantially as described above may be used to implement one or more steps of the method, as described throughout. With reference to
The shredded material is separated by the one or more primary separator units into the respective diaper materials, such as fluff and plastic. Thus, at step 210, the plastic is separated from the fluff, and at step 220, the fluff is separated from the plastic. In one aspect, these steps are performed substantially simultaneously. For example, a separator unit may be provided for separating the materials and comprises an inlet for receiving the materials (such as, but not limited to, the shredded material), means for separating the materials, and a first and second outlet for respective first and second materials (such as, but not limited to, fluff and plastic, respectively).
As described above, in one aspect the separator unit comprises a housing and separation cone for separating the materials. The separation cone is positioned within the housing and defines a space between the separation cone and the housing. The space may be configured for receiving separated fluff, such as through one or more apertures in the separation cone, and is in operative communication with the first outlet. The separation cone comprises an upper portion that is in operative communication with the inlet, and a lower portion in operative communication with the second outlet. The step of separating the materials may also comprise driving or drawing air into the separator unit to agitate or vacuum the materials, respectively, via air communication means.
At step 222, the separated fluff is conveyed to the condenser, and thereafter is conveyed at step 224 to a fluff baler. The separated plastic (and any additional fluff) is conveyed to a final separator at step 212. Additional fluff is separated at step 220, and is conveyed to the condenser along with previously separated fluff. The separated plastic is conveyed to a plastic baler at step 214. In one aspect, the fluff may be conveyed directly to the fluff baler without passing through a condenser.
In one aspect, the method also comprises providing a system fan configured for drawing or driving air through one or more components of the system. For example, the system fan may be configured for drawing air through the separator unit(s), to assist in the separation process for example. Optionally, drawing air through the separator unit(s) may assist in moving the materials from the separator unit to additional separator units or other system components. An air filter may also be provided for filtering the air being driven or drawn through the system. The system fan, or an additional fan, may be configured to release the filtered air into the ambient environment.
Referring now to
In this aspect of the system, the flow of material though the separator unit(s) 110 can be controlled in a four stage reclaim cycle. In one exemplary aspect, and as shown in
In one embodiment, the plurality of diverter valves 300 can comprise a first plurality of diverter valves 302 (diverter valves V1, V2 and V3). Referring to
In one aspect, diverter valve V1 is positioned in a raw feed line extending between the shredder 102 and the material intake of the first separator unit 110. Diverter valve V2 is positioned in a recycle feed line that is in communication with the material exhaust of the final sequential separator unit and the raw feed line. In one aspect, the recycle feed line joins the raw feed line between the diverter valve V1 and the material intake of the first separator unit. Diverter valve V3 is positioned in a bale feed line that is in communication with the recycle feed line and an intake of the final separator 120 of the plastic baler 122. The bale feed line joins the recycle feed line intermediate diverter valve V2 and the exhaust of the final separator unit. The first plurality of diverter valves 302 can also comprise diverter valve V4 that is positioned in a mini-bale feed line in communication with the recycle feed line and an intake of the final separator 120 of a second plastic baler 122. The mini-bale feed line joins the recycle feed line intermediate diverter valve V2 and the exhaust of the final separator unit.
In operation, for a predetermined time during the fill stage, the shredder 102 is actuated and diverter valve V1 is opened to allow for material from the shredder to be fed to the separation units. Diverter valve V2 is positioned in an open position to allow for material to be recycled as the unit is filling. In the fill stage, diverter valves V3 and V4 are positioned closed. For a predetermined time in the subsequent feed clearing stage, the shedder 102 is turned off so that no new material is inserted into the feed line. Diverter valves V1, V2, V3, and V4 remain in their respected fill stage positions during the feed clearing stage.
In the subsequent recycling stage, diverter valves V1, V3 and V4 are positioning closed. However, diverter valve V2 stays open so that material can be cycled repeatedly through the separator unit(s) 110 for a predetermined period of time. After the time period for the recycling stage lapses, the bale stage is initiated. In this bale stage, diverter valves V1 and V2 are closed and either one of diverter valves V3 or V4 is opened so the one of the baler units can be selectively fed. As one skilled in the art will appreciate, it is contemplated that after the time for the baling stage has elapsed, the system automatically will reinitiate the feed stage of the reclaim cycle.
It is contemplated that the plurality of diverter valves 300 can also comprise a second plurality of diverter valves 304 that are configured to selectively open in response to the selected baler in operation. In the embodiment illustrated in
Referring now to
It is contemplated that the distal end of each pressure line of the plurality of pressure lines can comprise a nozzle that can be moved to selectively select the application of pressurized air. In one aspect, the nozzle can be automatically controlled to select a preferred pattern or pressure of the applied pressurized air.
It is contemplated, in one aspect, that the first and second pressure sensors can provide feedback such that the pressurized air can be actuated from respective pressure lines in response to a noted differential between pressures sensed by the respective first and second pressure sensors. In another aspect, it is contemplated that pressurized air can be actuated from respective pressure lines in response to a noted expiration of a predetermined time period between actuations. In yet another aspect, it is contemplated that pressurized air can be actuated from respective pressure lines in response to either a noted differential between pressures sensed by the respective first and second pressure sensors or a noted expiration of a predetermined time period between actuations.
Referring to
It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.
This application claims priority to and the benefit of U.S. Provisional Application No. 60/888,900, filed on Feb. 8, 2007, which is incorporated in its entirety in this document by reference.
Number | Date | Country | |
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60888900 | Feb 2007 | US |