DEVICE FOR THE INSTALLATION OF VACUUM CONSOLIDATION DEWATERING HORIZONTAL DRAINS FOR DEWATERING SLUDGE PONDS
A device for installing horizontal drains in a coal combustion residual or other sludge pond consists of a trenching device that extends downwardly to the depth of required installation of the drains and an attachment through which the drains are fed during installation. The trenching device and attachment are mounted onto a carrier for floatation of the required equipment on the surface of a water-filled sludge pond. The carrier can be winched, hauled or driven across the surface of the sludge. A hydraulic system may be used to raise and lower the trenching device and attachment. The trenching device may be equipped with a chain driven blade mechanism or dredging device for the purpose of cutting a trench into the pond sludge, and a vibratory trenching device may be used to effectively liquefy the material to make the trenching device easier to pull or tow through the sludge in the pond.
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This non-provisional application claims priority based upon prior U.S. Provisional Patent Application Ser. No. 62/411,992 filed Oct. 24, 2016, in the names of David Seeger, Steven Kosler, David Morett, and Michael Fontenot entitled “DEVICE FOR THE INSTALLATION OF VACUUM CONSOLIDATION DEWATERING HORIZONTAL DRAINS FOR DEWATERING SLUDGE PONDS,” the disclosures of which are incorporated herein in their entirety by reference as if fully set forth herein.
FIELD OF INVENTIONThis invention relates to a device for the installation of horizontal drains below the surface of a sludge pond for the purpose of removing the water from (dewatering) the sludge. Various methods of using horizontal drains for dewatering sludge are generally known in the art and are referred to here as vacuum consolidation dewatering (VCD). This invention will describe a device used to install the drains below the surface of the sludge pond for the purpose of applying VCD.
BACKGROUND OF THE INVENTIONA variety of industries produce waste from operating processes that are accumulated in sludge ponds or tailing ponds, for example, coal combustion residuals (CCR) sediments in disposal ponds or impoundments. These ponds may require dewatering to mitigate their impact on the neighboring environment and human or animal health. Frequently local, state and federal governments may regulate aspects of managing these ponds and, in the case of CCR ponds, closure is also now required by U.S. environmental regulation.
CCR is known to be unstable when saturated. When saturated CCR is subject to shear strain, it densifies and expels water, resulting in a near total loss of shear strength. In this state, the material becomes a viscous fluid and may begin to slide or flow. This process may result in overtopping of impoundments and makes excavation and handling difficult to impossible. Reducing the water content of the CCR material by only a few percentage points has a dramatic effect on its behavior, allowing stable, near vertical cuts suitable for mass excavation.
Therefore, to facilitate closure, the ponds are sometimes dewatered by pre-drainage of the sludge to enhance strength and stability of the material and thereby provide a stable surface on which to operate earthmoving and grading equipment. VCD is one option for dewatering the sludge.
A typical VCD system consists of prefabricated drains made from plastic cores with a geotextile envelope or perforated plastic pipe or tube surrounded by a geotextile envelope, installed horizontally at a near-coplanar depth below the surface of the sludge pond. The drains are installed in a pattern throughout the area of the sludge pond that is to be dewatered. Herein is described a novel device useful in installing the horizontal drains.
SUMMARY OF THE INVENTIONA device that can be used to install horizontal drains in a sludge pond consists of a plow or other trenching device that extends to the depth of required installation into the pond and an attachment through which the drains are fed during installation. The trenching device and attachment are mounted onto a carrier that is capable of floating all of the associated equipment on the surface of a saturated and/or water-filled sludge pond, and can be winched or hauled across the surface of the sludge by winching devices. Various embodiments of the device may have a hydraulic system to raise and lower the trenching device apparatus and also, or alternatively, may include equipment for generating the power required to operate the hydraulic system.
Some embodiments of the device of the present invention include a location to carry the drain to be installed and storage for the required tools and hoses or pipes for connecting the drains to the vacuum and water pump unit that is part of the VCD system located near the drain installation area. In some embodiments, the device will also include a protected operator cab where the operator can either control the winches, or communicate with support staff. In such embodiments, the protected cab should provide adequate protection for the operator in the event that the winch cable should break.
In some embodiments the device could be towed behind suitable mechanized pond-compatible equipment in place of being moved by winches. A suitable hitching mechanism would be added to the device so that it could be connected to or trailed behind a pond-compatible mechanized vessel.
In some embodiments, the trenching device could have a chain driven blade mechanism or trenching device for the purpose of cutting a trench into the pond sludge. This embodiment could provide a reduced energy requirement of the equipment towing or of the winches pulling the VCD installation device across the surface of the sludge pond. The use of a blade mechanism or trencher may enable moving the device during installation (i.e., if the sludge is too hard or too solid, the towing equipment or the winches may be unable to move the trenching device across the pond, the chain trencher will solve that problem). A vibratory plow or trenching device may be used to effectively liquefy the material to make the trenching device easier to pull or tow through the sludge in the pond. This modification includes a vibrating device mounted to the shaft of the trenching device to vibrate the shaft during installation which will liquefy the sludge material of the pond making it easier to pull or tow the trenching device through the sludge.
Additionally in some embodiments, the carrier may have tracks to aid in moving the VCD installation device across dry sections of sludge rather than dragging the carrier across the sludge surface. These tracks may or may not be mechanized or self-propelled.
In yet another embodiment, the VCD installation device may include the simultaneous installation of drains at multiple depths in the sludge below the pond surface. Some ponds may be more effectively drained by the installation of drains at multiple depths below the surface. The trenching device may be modified to include the option of installing drains at different depths, for example, one drain may be installed at a depth of ten feet below the surface and a second drain at five feet below the surface.
Alternately, the trenching device may be modified to install drains at more than two depths below the surface simultaneously (i.e., drains could conceivably be installed every foot below the surface extending the full length of the trenching device shaft). For example, a fifteen feet long trenching device shaft could be modified to include drain installation at depths of fifteen feet below the surface and one ft. above that extending to the surface, i.e., installation of drains at fifteen feet below the surface, fourteen feet, thirteen feet, twelve feet, etc., extending to one foot below the surface.
The foregoing has outlined rather broadly certain aspects of the present invention in order that the detailed description of the invention that follows may better be understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures or processes for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims.
For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:
The present invention is directed to improved methods and systems for, among other things, the installation of vacuum consolidation dewatering horizontal drains for dewatering sludge ponds. The configuration and use of the presently preferred embodiments are discussed in detail below. It should be appreciated, however, that the present invention provides many applicable inventive concepts that can be embodied in a wide variety of contexts other than device for the installation of vacuum consolidation dewatering sludge ponds. Accordingly, the specific embodiments discussed are merely illustrative of specific ways to make and use the invention, and do not limit the scope of the invention.
Embodiments of the present invention include a device for the installation of the prefabricated drains in a horizontal, co-planar pattern below the surface of a sludge pond with the intent of putting a vacuum on the horizontal drains to withdraw water from the sludge pond material to dewater the sludge to the level of the drains below the pond surface.
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The VCD installation device 100 may be winched across the surface of the pond using the winch connections 114 on the device. Alternately, the VCD installation device 100 may be towed across the surface of the pond behind a suitable piece of heavy equipment using a hitch 116 on the device. In addition, either the hitch 116 or winch connection 114 can be used to haul the VCD installation device 100 to the next point at which a drain 106 should be installed into the pond.
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Those skilled in the art will recognize that the devices described above and shown on
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While the present device has been disclosed according to the preferred embodiment of the invention, those of ordinary skill in the art will understand that other embodiments have also been enabled. Even though the foregoing discussion has focused on particular embodiments, it is understood that other configurations are contemplated. In particular, even though the expressions “in one embodiment” or “in another embodiment” are used herein, these phrases are meant to generally reference embodiment possibilities and are not intended to limit the invention to those particular embodiment configurations. These terms may reference the same or different embodiments, and unless indicated otherwise, are combinable into aggregate embodiments. The terms “a”, “an” and “the” mean “one or more” unless expressly specified otherwise.
When a single embodiment is described herein, it will be readily apparent that more than one embodiment may be used in place of a single embodiment. Similarly, where more than one embodiment is described herein, it will be readily apparent that a single embodiment may be substituted for that one device.
In light of the wide variety of plowing methods and systems available, the detailed embodiments are intended to be illustrative only and should not be taken as limiting the scope of the invention. Rather, what are claimed as the invention are all such modifications as may come within the spirit and scope of the following claims and equivalents thereto.
None of the description in this specification should be read as implying that any particular element, step or function is an essential element which must be included in the claim scope. The scope of the patented subject matter is defined only by the allowed claims and their equivalents. Unless explicitly recited, other aspects of the present invention as described in this specification do not limit the scope of the claims.”
While the present system and method has been disclosed according to the preferred embodiment of the invention, those of ordinary skill in the art will understand that other embodiments have also been enabled. Even though the foregoing discussion has focused on particular embodiments, it is understood that other configurations are contemplated. In particular, even though the expressions “in one embodiment” or “in another embodiment” are used herein, these phrases are meant to generally reference embodiment possibilities and are not intended to limit the invention to those particular embodiment configurations. These terms may reference the same or different embodiments, and unless indicated otherwise, are combinable into aggregate embodiments. The terms “a”, “an” and “the” mean “one or more” unless expressly specified otherwise. The term “connected” means “communicatively connected” unless otherwise defined.
When a single embodiment is described herein, it will be readily apparent that more than one embodiment may be used in place of a single embodiment. Similarly, where more than one embodiment is described herein, it will be readily apparent that a single embodiment may be substituted for that one device.
In light of the wide variety of methods for device for the installation of vacuum consolidation dewatering horizontal drains for dewatering sludge ponds known in the art, the detailed embodiments are intended to be illustrative only and should not be taken as limiting the scope of the invention. Rather, what is claimed as the invention is all such modifications as may come within the spirit and scope of the following claims and equivalents thereto.
None of the description in this specification should be read as implying that any particular element, step or function is an essential element which must be included in the claim scope. The scope of the patented subject matter is defined only by the allowed claims and their equivalents. Unless explicitly recited, other aspects of the present invention as described in this specification do not limit the scope of the claims.
Claims
1. A method for installing a drain into a sludge pond, comprising:
- cutting a trench in a sludge pond at a single depth with a trenching device attached to a amphibious carrier;
- passing a drain into the trench through a downtube coupled with the trenching device; and
- transporting the amphibious carrier across the sludge pond.
2. The method of claim 1, further including removing water from the sludge pond through the drain with a vacuum.
3. The method of claim 1, further including removing water from the sludge pond through the drain with a water pump.
4. The method of claim 1, further including multiple downtubes for simultaneous installation of co-planar drains at multiple depths.
5. The method of claim 1, further including transporting the carrier across the sludge pond with a winch.
6. The method of claim 1, further including cutting a trench in the sludge pond with a chain driven blade attached to the trenching device.
7. The method of claim 1, further including liquefying sludge in the sludge pond with a vibrator attached to the trenching device.
8. The method of claim 1, further including transporting the carrier across dry sections of sludge with tracks attached to the carrier.
9. A device, comprising:
- a trenching device that cuts a trench in a sludge pond extending downwardly from a carrier to a single depth;
- a downtube through which drain may be passed into the trench coupled with the trenching device; and
- a amphibious carrier for transporting the trenching device across the sludge pond.
10. The trenching device of claim 9, further including vacuum attached to the drain to remove water from the sludge pond.
11. The trenching device of claim 9, further including a water pump attached to the drain to remove water from the sludge pond.
12. The trenching device of claim 9, further including multiple downtubes for simultaneous installation of co-planar drains at multiple depths.
13. The trenching device of claim 9, wherein the winch is attached to a motorized vessel.
14. The trenching device of claim 9, wherein the trenching device is equipped with a chain driven blade to assist in cutting a trench in the sludge pond.
15. The trenching device of claim 9, wherein the trenching device is equipped with a vibrator to liquefy sludge in the sludge pond as the trenching device cuts the trench in the sludge pond.
16. The trenching device of claim 9, wherein the carrier is equipped with tracks to aid in moving the carrier across dry sections of sludge.
Type: Application
Filed: Aug 14, 2017
Publication Date: Apr 26, 2018
Applicant: AECOM Technical Services, Inc. (Austin, TX)
Inventors: David Seeger (Austin, TX), Steven Kosler (Austin, TX), David Martinez-Morett (Austin, TX), Michael Fontenot (Austin, TX)
Application Number: 15/676,315