Patent Application
20140326821
1. Field of the Invention
The invention pertains to the field of methods and apparatus for recovery of landscape fabrics. More particularly, the invention pertains to removal of heavy gauge large area geotextile liners, as used in soil covers for industrial applications.
2. Description of Related Art
Geotextile liners comprise a wide range of sheet or mat materials used in various applications related to oil and gas exploration, construction, landscaping, and other industries. These geotextile liners may be porous, non-porous, natural or synthetic, and comprise one or more layers depending on their intended use. Most notably, the oil and gas exploration industry makes extensive use of geotextile liners in various aspects of drilling operations. Environmental concerns related to spillage of drilling fluids, hydro-fracking additives, and other potentially harmful contaminants dictate that drill pads are constructed with non-porous heavy gauge multi-ply geotextile liners as isolation layers comprising a heavy gauge plastic sheet ply between two separable felt plies that inhibit punctures from rocks or other objects above and below the geotextile liners. These isolation layers are formed from continuous lengths of geotextile material that are unrolled from bulk rolls in overlapping strips covering the entire area to be protected. The overlaps are then formed into water-tight seams by various methods such as heat sealing, welding the sheets together to create a single monolithic layer that may cover an area of 200,000 to 300,000 square feet. Gravel, sand, or soil distributed above the now isolated natural landscape provides a surface for vehicles and other machinery to move on, while chemicals potentially spilled in the area are prevented from leeching into ground water or contaminating native soils.
In other applications, geotextiles can be used to form a water-tight layer at the bottom of excavations to create artificial ponds for storage of fresh water used in hydro-fracking, or for storing contaminated water allowing natural evaporative mechanisms to return at least a part of the water to the environment without need for treatment. Similarly, ditches can be lined to channel contaminated fluids easily without fear of contaminating underlying soils or aquifers. In still further applications, geotextiles are used to create temporary road beds, protect embankments and protective berms against soil erosion, and other soil management purposes.
Many jurisdictions require that oil and gas drilling sites, whether productive or not, be returned to a “natural” state at the completion of drilling operations. Such requirements also apply to temporary ponds and other well related structures that would potentially pose a future environmental hazard, or are even just scenically unappealing.
In the past, it has been the practice in many cases to bury geotextile liners in-place. This has been particularly true of pond liners that can be pushed into the bottom of the pond excavation they line, and then buried with the soil previously removed from the same hole. However, this is not universally possible, and in some cases is environmentally undesirable as the geotextile liners themselves can become highly contaminated with drilling fluids and other harmful substances the liners are designed to block from seeping into underlying soils.
As a result, current best practice dictates complete removal of the liners from the drilling sites. The process of removal is complicated by the seamed connections that are created between sheets during the installation process. Whereas the geotextile liners can be applied directly to the ground in long sheets taken from a construction vehicle holding a bulk spool of material, the finished liner after seaming may cover an area of 200,000 to 300,000 square feet, making it unwieldy to handle in the removal process, and difficult to arrange in compact package for transport to landfills or recycling facilities.
Removal of the geotextile liners therefore first requires that the monolithic sheet be cut into smaller manageable sections. Currently, one method of doing this is to use a “pizza cutter” cutting wheel designed for scoring asphalt surfaces, attached to the bucket of a front end loader or other piece of heavy construction equipment. This method is not efficient however, as soft soils under the geotextile liners allow the target material to simply sink into the earth, rather than being cut by the wheel. As a result, cuts are completed manually using small knives such as gypsum cutters. In some cases this method is completely abandoned, and the geotextile liners are just torn into sections using a claw arm of a heavy construction vehicle.
Disposing of the geotextile liners is also difficult. In some instances the material is just packed into roll-off containers such as Dumpsters® and transported to landfills. In other cases, the material is placed into bailers, similar to the car crushers used in the scrap metal industry, and formed into blocks. In either case, the material so collected is not only unwieldy to handle and space consumptive in land fills, but also often unsuitable for recycling as the collection process also introduces rocks, soil, and other debris into the recovered material that may complicate or preclude the recycling of the high value polymers used to make the geotextile.
The embodiments described herein provide apparatus and a method for rapidly cutting geotextile liners into manageable uniform strips, and then easily collecting those strips onto rolls that are free of excessive debris, inexpensively stored and transported, require less space in land fills, and are easily dealt with by recycling facilities. In a first operation, a cutting apparatus with a lifting arm attached to a skid steer, fork lift, or other self propelled carriage is slid under the geotextile liner. As the lifting arm of the cutting apparatus is moved forward, it lifts the geotextile liner off the ground and directs it to a powered circular cutting disk extending through the lifting arm. The geotextile liner is thus cut, allowing the two halves of the liner to slide off the sides of the lifting arm, past the cutting disk and back onto the ground.
In a second operation, one end of a strip of Geotextile liner previously cut is attached to a disposable bobbin secured at each end by powered rotating spindles attached to a yoke frame of a collection apparatus which, in turn is mounted to a fork lift, skid steer, or other self propelled carriage. In cases in which the geotextile is of sufficiently heavy gauge, the bobbin is unnecessary and the geotextile can be attached directly to the powered rotating spindles, as it is self supporting. The powered spindles then wind the geotextile strip into a compact roll. As the collection apparatus lifts the geotextile liner strips off the ground, debris on the Geotextile strips rolls or slides off the material being collected through normal gravitation. Optionally, the collection apparatus can be fitted with a scraper and/or brush unit through which the Geotextile passes prior to being wound on the roll.
With reference now to the drawings,
The lifting arm 110 in this preferred embodiment is formed from a length of angle iron that has its one end welded to the mounting plate 120, with the angle pointing upward to form an apex. In this embodiment, a 6″×6″×½″ angle iron of roughly 5 foot length is used to form the lifting arm. However, these dimensions may vary widely depending on the target materials the cutting apparatus 100 is designed to separate. The opposite end of the lifting arm 110 is formed with a bevel 112 that allows the lifting arm 110 to easily wedge between the material to be cut and underlying surfaces, for the purpose of lifting the material to be cut off the underlying surface and guiding it along the lifting arm 110 to the cutting disk 150.
In this preferred embodiment, the lifting arm 110 is fixedly welded to the mounting plate 120 and reinforced with a sheet metal gusset 180 for lateral support. The back side of the mounting plate 120 is formed with an adaptor to fit upon the hydraulic arms 20 of the skid steer 10, to allow for both height adjustment and angulations of the mounting plate 120 and the attached lifting arm 110 in operation. In other embodiments where the self propelled carriage does not have such hydraulic arms 20, the attachment of the lifting arm 110 to the mounting plate 120 is made with a pivot that can be locked in position holding the lifting arm at an optimal angle relative to the horizontal, and/or sprung to allow for a range of vertical movement of the lifting arm 110 as it traverses potentially uneven terrain, with articulated linkages providing lateral support relative to the mounting plate 120.
One end of a service boom 130 is also welded to the mounting plate 120 parallel to, and slightly above, the top of the lifting arm 110. At the opposite end of the service boom 130, a motor 140 is mounted to drive a cutting disk 150 that penetrates through a cutting disk slot 190 in the lifting arm 100. In one preferred embodiment, the motor 140 is a hydraulic motor 140. This selection is made for its high torque characteristics and because most heavy and light construction vehicles have hydraulic systems that provide industry standard quick release connectors that accommodate hydraulic accessories. Hydraulic hoses 160 lead from the motor 140 for this purpose and connect to appropriate fittings on the skid steer 10 or other self propelled carriage that is employed.
In other embodiments, shown in
A cutting disk 150 guard 170 is employed to prevent injury from personnel coming in contact with the cutting disk 150, or from debris propelled by the cutting disk 150.
While the motor 140, cutting disk 150, and service boom 130 are shown such that the cutting disk 150 penetrates the lifting arm 110 cutting disk slot 190 from above, it is understood that this is only one preferred embodiment, and the cutting disc 150 can easily be arranged with its rotational axis underneath the lifting arm 110, allowing the disc 150 to penetrate the lifting arm 110 cutting disk slot 190 from below. The angle of the lifting arm 110 relative to the ground provides sufficient space for this purpose. In this case the cutting disk guard 170 is modified with flanges extending laterally away from the cutting disk 150 on each side, and forward of the cutting disk 150, to prevent the geotextile being cut from riding up and over the cutting disk. In this arrangement, the service boom 130 and motor 140 might also be mounted below the lifting arm 110.
In one preferred embodiment, the cutting disk 150 is an 18″ diameter concrete blade, chosen for its ability to cut through not only the geotextile target material, but also any rocks or other debris that may be carried into the blade as it traverses a cutting pathway. The choice of blade is, however, flexible and in other embodiments is chosen to include a conventional toothed blade, a chain toothed blade, sharpened disk, or other blade configuration appropriate to the target material to be cut.
Uniform width and straightness of cut can be important later in the rolling process. Outriggers 122 are provided for this purpose. In use, the outriggers 122 are adjusted such that guides 124 affixed to their outer end indicate a desired distance from the cutting disk 150 to a reference line used for guiding the cutting process. In one preferred embodiment the guide 124 is a chain that hangs close to the ground and can be easily sighted relative to the reference line of travel being used. In other embodiments, this guide 124 is a cable, laser light, adjustable rod, or other reference device.
Typically the operator has one straight edge of the geotextile liner to use as a reference, or uses a seam in the geotextile liner as a reference. Hence, the operator ensures that on each pass with the cutting apparatus, depending on the location of the reference edge relative to the direction of travel, the respective guide 124 follows the chosen reference. In this manner consistent width strips of geotextile are cut in straight uniform widths from the previously assembled geotextile liner.
A collection apparatus is employed to collect the strips of material previously cut into compact rolls that are easily stacked, space efficient, and accommodating to recyclers. Generally such a collection apparatus winds the strips on a bobbin, however in the case of heavy gauge geotextiles, a bobbin is not required as the geotextile is self supporting. The collection apparatus also provides spindles for holding the bobbin and causing it to rotate, creating a roll of geotextile, or for direct attachment of the geotextile if it is of sufficiently heavy gauge to be self supporting when it is rolled around the rotating spindles. The collection apparatus also has a frame or yoke that holds the bobbin or geotextile in operation provides for mounting on a self propelled carriage, provides a motive power source for the spindles, and have at least one side moveable or removable so completed rolls can be deposited for transport.
Referring now to
The support bar 220 is hollow and accepts, at each end, yoke arms 230 which slide in and out of the support bar 220 via movement of linear actuators 240 mounted at one end to the support bar 220 and at the other end to the yoke arms 230. Movement of the linear actuators 240 thus increases or decrease the distance between the spindles 250 mounted on the lower end, and inner side, of the yoke arms 230. Motors 260 mounted on the lower end, and outer side of the yoke arms 230 provide motive power for the roller spindles 250. In other embodiments, a single linear actuator is used to move both yoke arms 230, or a single yoke arm 230 allowing the bobbin 253 to simply slide off the spindle 250 on the other yoke arm. In a preferred embodiment, two sliding yoke arms 230 are employed, and hydraulic pistons are used as linear actuators 240. Also in this preferred embodiment, the motors 260 are hydraulically driven. Hydraulic power for both the motors 260 and hydraulic piston linear actuators 240 is provided by hydraulic lines 290 which are in turn connected to the self propelled carriage 12 hydraulic system via industry standard quick-release hydraulic fittings provided on a wide variety of construction equipment for this purpose. In alternative embodiments, electrically driven linear actuators 240 and electric motors 260 are employed, and operatively connected to the electrical system of the self propelled carriage.
Accordingly, the collection apparatus 200 is combinable with numerous fork lift devices, or through alternative adaptive fixtures (clamps, brackets, etc), with bucket loaders, skid steers, agricultural tractors or other equipment capable of providing accessory hydraulic or electrical outputs and offsetting the weight of the roller and material it accumulates in the rolling process. In alternative embodiments, shown in
The collection apparatus spindles 250 are conical in shape and have at least one slit through their diameter to allow for contraction and expansion of the spindle 250 when pressure is applied inwardly by moving the spindles 250 closer together, or removed when the distance between the spindles 250 is increased.
Generally, prior to rolling operations, the yoke arms 230 are spread to their maximum distance through extension of the linear actuators 240. At this time a bobbin 252, which can be made of a length of PVC pipe, is preferably placed over one spindle 250, and the distance between the yoke arms 230 decreased until the bobbin 252 is held firmly in place via friction between its inner surface and the outer surface of the spindles 250. PVC pipe 252 is chosen for its low cost, general availability, and compatibility with later recycling of the geotextile rolls. However, metal tubes, or bars fitted in the slots 255 of the spindles 250 may also be used for this purpose.
Having placed the bobbin 252 in place, one end of a previously cut geotextile strip is affixed to it, either through tapes or glue, or using an attachment such as a slot 253 cut in the bobbin 252 or hooks, barbs, or clamps on the surface of the bobbin 252. The spindle 250 motors 260 are then activated causing the bobbin 252 to turn, rolling the geotextile strip 15 onto its outer circumference. The strength of the bobbin 252 is not a critical parameter, as the geotextile roll becomes self-supporting after only a few turns, and additional lateral pressure on the roll can be applied as necessary to keep the roll from slipping during rotation by moving the spindles 250 closer to the center of the roll using the linear actuators 240.
In some cases, the geotextile is of sufficiently heavy gauge, for example 60-80 mil (one mil=one thousandth of an inch), it is self supporting, so that the bobbin 252 may be omitted. Instead, the geotextile 15 is inserted into slots 255 in each spindle 250. The collection apparatus is shown in
Guide disks 270 at the thick end of the spindles 250 near the yoke arms 230 help ensure that the geotextile rolls in a uniform manner and does not wander to either side. Additional roll guides 295 are placed on the inside of the yoke arms 230 to further assist in this alignment procedure. These additional roll guides are either welded to the lower portion of the support bar 220, following the inner contour of the yoke arms 230, or hinged at the upper corner of the yoke arms 230. Chains 296 or cables also connecting the support bar 220 with the roll guides 295 maintain the location of the lower portion of the roll guides 295 near the rolled material when the yoke arms 230 are spread to release the final roll. In this manner, both spindles 250 can be removed from the finished roll without one or the other becoming stuck in the center of the completed roll.
A pre-cleaning apparatus 500, shown in
While
The self propelled carriage 30 is preferably powered by a gasoline engine 32, but is also capable of being powered by an electric motor. A universal joint 34 being powered by the self propelled carriage 30 mates with a drive shaft 36 that in turn provides power to a right angle transmission 38 to which the cutting disk 150 is attached. The lifting arm 110, service boom 130, and blade guard 170 are configured relative to each other and the mounting plate 120 as previously described. Additionally, a height adjustable wheel 35 is added under the lifting arm 110 to provide stability and to ensure that the bevel 112 of the lifting arm is optimally positioned to slide under the material to be lifted, but does not dig into potentially sensitive underlayment, such as fiberboard or plywood found under large area carpeting, or roofing membranes, for example.
The collection apparatus 200 is similarly scalable for smaller operations as shown in
Hence, these small scale embodiments are employable for removing man-made ground covering such as Astroturf® in indoor settings, large scale wall to wall carpeting in convention centers or other large spaces, roofing membranes used on residential and commercial structures, and any other large scale covering previously applied in areas that are not accessible to large scale machinery.
When used in combination, the cutting apparatus 100 and collection apparatus 200 provide an efficient, cost effective, and ecologically suitable means of recovering unwanted geotextiles. This method can be summarized as shown in
Alternatively, when heavy gauge, self supporting geotextiles are being collected and a bobbin 252 is omitted, this method can be summarized as shown in
Accordingly, it is to be understood that the embodiments of the invention herein described are merely illustrative of the application of the principles of the invention. Reference herein to details of the illustrated embodiments is not intended to limit the scope of the claims, which themselves recite those features regarded as essential to the invention.
