Patent Application
20130174517
Not Applicable
1. Field of Invention
The invention relates to methods and processes useful in recycling carpet. More particularly, this invention relates to methods and processes whereby carpet is reduced into component materials by separating carpet fibers in the carpet from calcium carbonate that forms the backing material of the carpet.
2. Description of the Related Art
The concept of recycling and reclaiming waste materials and refuse for use in starting material for new products is well known. Environmental concerns and landfill regulations have placed an increasing emphasis on the need to recycle and decrease waste in the manufacturing of goods and products. Furthermore, manufacturing processes that utilize recycled goods can also decrease manufacturing costs, thereby lowering the price of the goods.
There is a growing awareness of the need to reclaim raw materials from used carpets for use as starting materials in numerous industries. According to the Carpet America Recovery Effort's 2010 Annual Report statistics, over six (6) billion pounds of carpet were discarded in 2010. Of those six (6) billion pounds of discarded carpet, less than one (1) billion pounds were recycled. Over four and one-half (4½) billion pounds were placed in landfills. Accordingly, there is a continuing need for new efficient and convenient methods and devices for recycling carpet.
Generally, carpets comprise fibrous materials and backing materials which may be separated and harvested for reintroduction into carpeting as starting material. More specifically, many modern carpets comprise fibers which are fabricated from nylon, polypropylene, polyethylene tetraphthalate (PET), or other such materials, together with a backing which usually includes polypropylene, calcium carbonate, and latex glue. In the field of recycling carpet, emphasis is placed on reclaiming nylon fibers from carpet due to the relative cost of nylon in comparison to the other materials discussed above. However, in order to reclaim nylon from carpet such that the reclaimed nylon may be used in the manufacture of new carpet, the nylon must be separated from the backing materials to which it is typically adhered.
Several carpet recycling processes are well known in the art. For instance, one method of recycling carpet includes sending the carpet through a machine which shaves nylon fibers from the backing material in the carpet. However, this method typically results in reclamation of only that portion of the nylon fibers in the carpet which protrude beyond a threshold distance from the backing material. Thus, a significant percentage of the nylon fibers in the carpet must be discarded along with the backing material.
U.S. Pat. No. 7,635,099 issued to Meredith et al. teaches another method of recycling carpet, whereby carpet pieces are shredded, screened to separate fibrous materials from backing materials, and then introduced into a liquid slurry and centrifuged. However, the method disclosed in Meredith et al. is limited in its ability to separate calcium carbonate in the backing material of carpet from nylon fibers in the carpet. Furthermore, none of the known processes are capable of immediate breakdown and recycling of wet carpet. This presents an issue when, for instance, a carpeted building is flooded and replacement of carpet in the flooded building and recycling of the wet carpet is desired. The carpet in the flooded building becomes wet, and is therefore no longer capable of being recycled through known processes. Thus, instead of the carpet's components being recycled and reclaimed for use as starting material, the wet carpet rolls are often placed in a landfill.
In light of the above, there is a need in the art for a carpet recycling process that is capable of receiving either wet or dry carpet rolls and separating the carpet fibers from the backing material for reintroduction into carpeting as starting material.
A carpet recycling method is disclosed according to several embodiments of the present general inventive concept. The carpet recycling method, in certain embodiments, may include, in a toroidal flow pulper, disintegrating carpet in a quantity of liquid to form a slurry of fibrous carpet materials and carpet ash. The carpet recycling method may further include separating at least a portion of the fibrous carpet materials from the slurry, drying the separated fibrous carpet materials, isolating at least a portion of the carpet ash from the slurry, and drying the isolated carpet ash. In several embodiments of the present general inventive concept, a first output comprising dried separated fibrous carpet materials and a second output comprising dried carpet ash are produced, the first and second outputs being suitable for use as starting material in numerous industries.
In certain embodiments of the present general inventive concept, the toroidal flow pulper used in disintegrating the carpet may include a tank sized and shaped to receive the carpet and the quantity of liquid. The toroidal flow pulper may further include a pulper in fluid communication with the tank. In certain embodiments, the pulper may comprise a stationary stator and a rotatable rotor having a plurality of blades defined thereon. The rotor may be nested within and cooperate with the stator to define a reduction and attrition zone therebetween. The rotor may be coupled to a drive shaft, and the drive shaft may be in operable communication with a motor configured to rotate the drive shaft and the rotor. Thus, rotation of the rotor in relation to the stator may operate to shear the carpet while simultaneously drawing the liquid and the carpet into and through the reduction and attrition zone, thereby disintegrating the carpet to form the slurry.
In certain embodiments of the present general inventive concept, the operation of disintegrating carpet is performed by placing the carpet and a the quantity of liquid in the tank of the toroidal flow pulper, rotating the rotor in relation to the stator, pumping the carpet and the liquid through the reduction and attrition zone, thereby shearing the carpet, and recirculating the sheared carpet and the liquid to the tank.
The carpet recycling method may, in some embodiments, further include the operation of packaging the dried separated fibrous carpet materials into transportable units. For example, the operation of packaging the dried separated fibrous carpet materials may, in certain embodiments, be performed by baling the dried separated fibrous carpet materials using a baler.
In certain embodiments of the present general inventive concept, the operation of separating at least a portion of the fibrous carpet materials from the slurry may comprise placing the slurry in a screening chamber defining a series of apertures sized to allow the liquid and the carpet ash to pass through the apertures but to limit the fibrous carpet materials from passing therethrough. Such operation may further comprise agitating the screening chamber and applying additional liquid to an interior of the screening chamber to urge the liquid and the carpet ash through the apertures. The operation of isolating at least a portion of the carpet ash from the slurry may comprise placing the slurry in a hydrocyclone defining a conically-shaped chamber adapted to rotate about a central axis thereof, rotating the chamber of the hydrocyclone, thereby urging circulating separation of the at least one portion of the carpet ash from the liquid of the slurry; and allowing the at least one portion of the carpet ash to fall from a lower portion of the chamber.
In certain embodiments of the present general inventive concept, the operation of drying the isolated carpet ash may be performed by processing the isolated carpet ash through at least one of a vacuum filter and a thermal drying apparatus.
In certain embodiments of the present general inventive concept, at least one of the operations of drying the separated fibrous carpet materials, isolating at least a portion of the carpet ash from the slurry, and drying the isolated carpet ash produces a third output comprising the liquid. In these embodiments, the carpet recycling method may further comprise the operation of directing the third output to the toroidal flow pulper for use in disintegrating additional carpet.
The above-mentioned features of the invention will become more clearly understood from the following detailed description of the invention read together with the drawings in which:
A carpet recycling method, in accordance with several features of the present general inventive concept, is disclosed herein and in the accompanying figures. One embodiment of a carpet recycling method, or method, is shown schematically at 10 in
With reference to
Referring now to
Referring to
It will be understood that, whereas certain prior art devices having blade assemblies are not suitable for disintegrating wet carpet, the torodial flow pulper 18 as described above and in the accompanying figures can disintegrate carpet that starts wet or dry into carpet fibers and carpet backing without becoming tangled and jamming. However, it will also be understood by one of skill in the art that the degree to which the carpet 16 is sheared by the toroidal flow pulper 18 may vary depending upon a large number of factors, including but not limited to the relative size of the various components of the toroidal flow pulper 18, the speed at which the rotor 26 rotates in relation to the stator 24, the selected size of the reduction and attrition zone 28, and the number of times the carpet 16 is recirculated through the reduction and attrition zone 28. However, it will generally be recognized that the toroidal flow pulper 18 as described above and in the accompanying figures is capable of dividing carpet into pieces having sizes as large as a few square inches in area, and is also capable of disintegrating the carpet 16 into its component mixed carpet fibers and carpet ash, and is further capable of reducing the size of the fibers themselves. Accordingly, with regard to use of the above-discussed toroidal flow pulper 18 manufactured and sold by Bolton Emerson Americas, LLC and marketed under the brand name “Tornado” to accomplish the disintegration operation 12 of the method 10, in several embodiments of the method 10, such disintegration 12 of the carpet 16 is accomplished by processing the carpet 16 through the toroidal flow pulper 18 for approximately five (5) to ten (10) minutes with the rotor 26 rotating at approximately four hundred thirty (430) rounds per minute. In one embodiment, the carpet 16 is processed through the toroidal flow pulper 18 for six (6) minutes with the rotor 26 rotating at approximately four hundred thirty (430) rounds per minute.
Referring to
The separation device 48 may include one or more of any of a variety of known devices which are suitable to accomplish separation 50 of the mixed carpet fibers from the mixture of water 14 and carpet ash, including but not limited to various types of liquid presses, such as for example a belt press, a filtration device, a screening device, or the like. For example, in several embodiments, the separation device 48 is provided by a screening device. However, it is not the intention of the applicant to limit the method 10 of the present general inventive concept to use of any particular type of device to accomplish separation 50 of the mixed carpet fibers from the mixture of water 14 and carpet ash.
In some embodiments, the separation device 48 is provided by a screening device which includes generally a screening chamber that is lined with a series of apertures sized to separate the carpet fibers from the carpet ash. It will be recognized that the particular aperture sizes can vary without departing from the scope or spirit of the present general inventive concept. However, it will be understood that the apertures are generally sized to substantially retain the carpet fibers within the screening chamber while permitting smaller particles and liquid to pass therethrough. For example, in one embodiment, the apertures defined by the screening chamber are each sized to approximately one (1) micron.
Referring to
It will further be recognized that, depending upon the type of device utilized in the separation operation 50, following the separation operation 50, the carpet fibers may still retain a significant moisture content, sometimes as much as ninety (90) percent by weight. Accordingly, and with reference again to
It will be understood that, in certain embodiments, the drying device 76, in addition to producing dried mixed carpet fibers, produces an output of water 94 separated from the mixed carpet fibers. In some embodiments, the outputted water separated from the carpet fibers by the drying device 76 may be optionally directed 82 back for additional use in the toroidal flow pulper 18. However, it will be understood that such optional direction 82 of the outputted water 94 is not necessary to accomplish the present general inventive concept.
In an optional step following the operation of drying 52 the fibrous carpet materials, the dried carpet fibers are packaged 78 into transportable units. In some embodiments of the present invention, the mixed carpet fibers are collected from the drying device 76 and transferred to a suitable packaging device 80, such as for example a compacting apparatus. In some embodiments, a bailer (not shown) is utilized whereby a collection of mixed carpet fibers are placed in a compacting zone where a compacting member compresses the carpet fibers into a bale that can be circumferentially tied and easily loaded onto a pallet or like transporting unit. In their compacted state, the mixed carpet fibers, can then be easily transported for further use, such as for example for use as starting material in various industries. In any case, following drying 52 of the mixed carpet fibers, an output 96 of dried mixed carpet fibers is produced.
Returning to
In several embodiments, the isolation device 88 is provided by a hydrocyclone which includes a conically-shaped container which is adapted to spin about a central axis of the conically-shaped container, such that upon receiving the mixture, such spinning of the hydrocyclone encourages circulating separation of the carpet ash from the liquid. More specifically, because the carpet ash in the mixture has a density greater than water, spinning of the hydrocyclone encourages the carpet ash to fall through the bottom of the hydrocyclone while the water in the mixture is retained therein. In several embodiments, the state of the carpet ash falling through the bottom of the hydrocyclone is a moist solid. Thus, it will be understood that, while the hydrocyclone serves to isolate the solid particles from a portion of the water in the mixture, the solid particles may contain a certain quantity of moisture.
Referring again to
After isolating the carpet ash 84, the carpet ash is dried 90 in order to purge it of any remaining moisture. Thus, an output of dried carpet ash 98 is produced. In some embodiments, the primarily-solid carpet ash that is isolated 84 by the isolation device 88 is then transferred to a carpet ash dryer 92, such as for example a rotary vacuum filter. The rotary vacuum filter filters the semi-solid mixture by rotating an apertured drum inside of a housing. Washing water is introduced to clean the semi-solid mixture which is urged by a vacuum force against the exterior of the rotating drum, within the housing. The liquid accompanying the solid carpet ash, as well as the washing water introduced inside the housing, is sucked through the apertured, rotating drum, leaving only solid particles adhered against the exterior of the apertured drum. The solid ash may then be preserved while the water may be collected as output water and recycled back to the toroidal flow pulper 18 as discussed above. In one embodiment, after processing the carpet ash through the rotary vacuum filter as discussed above, the carpet ash is then sent to a thermal drying apparatus where electric heat and air cooperate to create a blow-drying effect that is applied directly to the carpet ash. However, numerous suitable devices and configurations for drying 90 the carpet ash to create the output of dried carpet ash 98 will be readily apparent to one of suitable skill in the art, and such other devices and configurations may be used without departing from the spirit and scope of the present general inventive concept.
From the foregoing, it will be recognized that a carpet recycling method has been provided in accordance with various embodiments of the present general inventive concept. Specifically, the carpet recycling process enables a user to recycle carpet pieces and harvest at least two outputs, namely, an output of mixed carpet fibers and an output of predominantly calcium carbonate carpet ash. In several embodiments, the mixed carpet fibers recovered by the carpet recycling method disclosed herein contain an ash content that is less than five (5) percent, which presents a significant improvement over other known carpet recycling methods.
While the present invention has been illustrated by description of several embodiments and while the illustrative embodiments have been described in detail, it is not the intention of the applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional modifications will readily appear to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and methods, and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of applicant's general inventive concept.
This application claims the benefit of U.S. Provisional Patent Application No. 61/585,270, filed on Jan. 11, 2012, which is incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 61585270 | Jan 2012 | US |
