Embodiments disclosed herein relate to systems and methods for removing liquidized materials from bodies of fluid and, more particularly, to apparatus and methods for removing sediment and associated matter from water reservoirs, ponds or the like.
It is well known, in storm water and industrial liquid waste management systems, to provide ponds to receive contaminated water flows for treatment prior to discharging the treated water into local watersheds or sewers, where permitted. Treatment typically entails a first step of enabling fluid residence within the pond to allow for a time dependent, water quality improvement process to take place, such as sedimentation of suspended matter including, but not limited to, silt, sand and clay. The initial residence step may include additional treatment or the additional treatment may be included in one or more subsequent steps, such as secondary and tertiary steps, to encourage composting, nutrient removal and the like for further clarifying the treated water.
In urban areas, municipal water ponds typically form a water feature about which residences may be located. Many of these constructed water bodies, particularly those in municipal settings, are of a size and configuration such that most of the pond surface area is within a fixed distance, for example about 50 m, of the pond's edge. Other ponds, such as industrial ponds, tailings ponds used in mining or oilsands processing or a variety of other industrial processes, are typically similarly sized. Further, the constructed water bodies may have components associated therewith from which much of the surface area of the pond is within the fixed distance. Over time, solid materials such as sediment may build up in these ponds, reducing the pond's utility. Applicant believes that the sediment which accumulates in these ponds tends to be of a uniform, slurry consistency.
A conventional remedy to pond sediment accumulation includes draining the pond in order to provide access for excavating machines and conveyance vehicles to remove and dispose of the sediment. One complication to such excavation processes is the close proximity of the residences, construction sites, landscaped terrains with trees or other valuable vegetation or other features which may surround the perimeter of the pond and restrict access thereto by the excavation equipment and sediment disposal carriers.
In municipal environments, remediation processes are often scheduled during the winter. The pond may be drained into the municipal sewer system if drainage onto natural water ways is not permitted during the winter months.
A plurality of backhoes is often employed in a chain arrangement to shovel sediment from a point in the pond to a point closer to the shore and from there to a point on shore for loading onto trucks. The process can, for example, take from 1 to 2 months for remediation of a typical storm water pond. Current cost is about $3M for removal of sediment from each pond. Sediment removal is performed for each pond once every 10 to 20 years or so. Furthermore, Applicant believes that a current cost of disposing of the removed sediment is about $2M for each pond, particularly if special disposal procedures are required, such as contaminated material landfill disposal as may be required for some stormwater or industrial water ponds.
The conventional remediation process, as described, is laborious, requires a long time to complete and is very expensive. Disposal of the drained water may be impractical due to government regulations and permits. Conventional pond remediation also tends to be disruptive to the peace and enjoyment of the local residents. Disposal of removed remediation materials, such as the sediment slurry, is expensive and impractical. Disposal typically involves a process of spreading slurry on other lands to allow the slurry to dry or thickening of the slurry using specialized dewatering equipment.
Shoreline and barge-mounted dredging has been exploited to remove materials from the bottom of water bodies as taught in U.S. Pat. No. 4,942,682 to McDowell. McDowell utilizes a self-contained, reversible dredging module adapted for use as an attachment to a conventional backhoe machine, thereby creating a two-segment backhoe.
Applicant believes that access to the pond surface using such a two-segment backhoe is limited, such as to about 15 m from the shore. As the surface of municipal ponds, industrial ponds or tailings ponds used in mining, oilsands and a variety of other industrial processes have a surface area typically extending much further than 15 m from the shore, a major portion of the pond surface is out of reach of the apparatus as taught in McDowell, unless the pond is almost completely dewatered or the apparatus is supported by a floating barge. Use of a floating barge sufficient in size to accommodate the apparatus of McDowell may be impractical, particularly for use in ponds where access is restricted such as in urban settings in close proximity to residences, construction sites, landscaped terrains and other types of access restrictions. McDowell does not disclose any sophisticated systems which might permit programming remediation patterns or monitoring the location of such apparatus relative to the pond surface and perimeter.
U.S Pat. No. 4,911,831 to Davison et al teaches a self-propelled, floating apparatus and land-based crane gantry for skimming sand from beds of slow sand filters. An auger skimmer removes sand to a pre-determined depth and conveys the sand to a pump for delivery to a remote location via a floating conduit. The pump is located mid-point along the intake conduit away from the point of intake of the sand/water slurry. The slurry has a preferred density of 20% w/w sand. Augur depth is tracked and controlled however azimuthal location is not. Sonar, laser, audio and camera sensors are employed to set and monitor dredging depth. The apparatus of Davison et al is specifically designed for sand filter beds used in water purification plants and requires that weeds be removed from each filter prior to utilizing the sand skimmer. Cutters for removing weeds prior to suctioning the sand may be incorporated.
A floating, mechanical clamshell and hydraulic dredge is disclosed in U.S. Pat. No. 5,311,682 to Sturdivant. The dredge apparatus is fit with angular and linear displacement sensors to permit geo-location for data logging and quality assurance of work completed. Sturdivant is not shoreline based and must navigate the pond to each site requiring remediation. Sediment is removed at near in situ water content, as re-suspension due to water disturbance is minimized. High density sediment is removed and conveyed at low speed and may require pre-pump particle size reduction. A pipeline speed of 1 to 2 m/s compared to the prior art speeds of 2 to 5 m/s for a slurry density of 0% to 30% are quoted. Dredging operations may be tracked and optimized by electronically linking sensors on the apparatus to a data processor such as a PC or a PLC. Sensors on the apparatus may include GPS sensors.
An oil skimmer for use in remediation of oil spills is disclosed in published PCT application WO 2012/027620 to Brown et al. A platform or vehicle having an extendable arm is fit with a fluid skimmer for removing contaminants, particularly oil, which are at or near the surface of contaminated bodies of water such as rivers, lakes, marshes and the like. A pump on the skimmer collects contaminants from the water surface and delivers same to a collection reservoir, via a conduit. Alternatively, instead of a pump, a land based service apparatus embodiment utilizes a boom connected directly to a vacuum truck for sucking water and contaminants from the surface of the water.
Systems and methods for improving water quality in ponds is described in Applicant's issued U.S. Pat. No. 8,333,895, incorporated herein by reference in it's entirety, with respect to Applicant's NAUTILUS POND®. The described systems focus on enhancing sediment and/or nutrient removal performance which are generally considered important functioning components of a pond system. Typically, removal of sediment accumulations from such ponds would require taking an entire pond offline for the duration of a sediment removal operation.
Land-based pond remediation, as disclosed in the prior art, appears to be limited largely by the reach of the equipment used, characteristics of the sediment slurry or other remediation material targeted for removal and pond operation. These limitations are exacerbated in developed areas due to additional constraints imposed by architectural features, landscaping and legislative considerations. Whereas these limitations may be overcome to some extent with the use of an improvised assortment of currently available equipment or a floating apparatus, the equipment is complex and adds constraints of transportation, provision of access to pond and adapted waste conveyance structures.
Clearly there is interest in apparatus, methods and systems which facilitate remediation of stormwater collection ponds efficiently and effectively and at reduced cost compared to conventional systems currently in use. There is clearly a need for effective and efficient apparatus for removal of matter from bodies of fluid or reservoirs which is capable of extended reach into locations having limited or restricted access and/or sensitive access.
Embodiments disclosed herein provide methods, systems and apparatus for remediation of water bodies, the apparatus having an extended reach compared to prior art apparatus, for use in ponds situated in urban, industrial and remote areas. A multi-articulated boom is rotatably connected to a base which can be a mobile base or a stationary structure. A slurry-capable pump, connected to the distal end of the boom, is moved about the water body, such as a stormpond, by rotation and manipulation of segments of the boom for suctioning sediment slurry from the water body. The boom can be manipulated to reach over obstacles such as houses, garages, landscaping positioned between the apparatus and the pond permitting greater access to the pond thereby reducing the number of apparatus required. In systems disclosed herein, the water body may have structured platforms and accessways built therein to permit the apparatus to be deployed within the perimeter of the water body thereby permitting even greater access to the entirety of the water body for remediation operations. Geolocating apparatus operatively connected to the boom and/or the pump permit monitoring of the movements of the boom and pump enabling more efficient remediation with minimal overlap particularly when the pond is full of water. Other attachments such as blenders and fluid-addition jets permit controlling of the fluid properties of the slurry removed by the pump.
Therefore in one broad aspect, apparatus for extended reach remediation of a water body comprises a base and a multi-articulated, extendable boom extending from a distal end to a proximal end and rotatably secured to the base. A fluid conveyance conduit is secured to the extendable boom and extends therealong between the distal end and proximal end of the boom. A slurry-capable pump is supported at the distal end of the boom, the pump having a pump outlet fluidly connected to a distal end of the fluid conveyance conduit. The pump receives pumpable material at a pump intake and pumps the pumpable material through the fluid conveyance conduit to a proximal discharge end of the conduit for discharge therefrom.
The multi-articulated boom comprises a plurality of boom segments which are hingedly connected therebetween. The length of the boom and the maximum reach thereof is generally governed by the length of each of the plurality of segments. The pump is lightweight so as to avoid loading a distal end of the boom so much so that the apparatus becomes unstable. Outriggers, ballasting strategies and buoyance devices can be used where heavier attachments to the pump are used. Further, at least a distal segment of the boom can be reduced somewhat in length to assist with overall stability of the apparatus without compromising the effectiveness of the extended reach of the apparatus.
In another broad aspect, a system for remediation comprises an extended reach apparatus having a base and a multi-articulated, extendable boom having a distal end and a proximal end rotatably secured to the base. A fluid conveyance conduit is secured to the extendable boom and extends therealong between the distal end and the proximal end thereof. A slurry-capable pump is supported at the distal end of the boom. The pump has a pump outlet fluidly connected to a distal end of the fluid conveyance conduit, the pump receiving pumpable material at a pump intake and pumping the pumpable material through the fluid conveyance conduit to a proximal discharge end of the conduit for discharge therefrom. A water body having a perimeter contains the pumpable material therein for removal therefrom using the extended-reach apparatus.
The system further comprises platforms located within the perimeter of the water body for locating the apparatus thereon to more effectively utilize the extended reach of the apparatus for remediation of substantially the entirety of the pond surface. Alternatively, the pond can be drained and the apparatus moved into the pond perimeter. The apparatus is supported on the bottom of the pond or can be supported on temporary supports such as swamp mats positioned therein.
In yet another broad aspect, a method for remediation of a water body comprises locating an apparatus having a multi-articulated, extended-reach boom for operatively supporting a slurry-capable pump at a distal end thereof at a perimeter of the water body. The boom is manipulated for moving the slurry-capable pump about the water body, the pump recovering pumpable materials therewith from the pond. The pump pumps the pumpable materials to the perimeter of the pond for removal therefrom.
Where the perimeter of the water body exceeds the reach of the multi-articulated, extended reach boom, the method further comprises relocating the apparatus to at least another location about or within the perimeter of the pond. The steps of manipulating the boom for moving the pump and pumping the pumpable materials are repeated.
Embodiments disclosed herein provide methods, systems and apparatus for pond remediation, the apparatus having an extended reach compared to prior art apparatus, for use in ponds situated in urban, industrial and remote areas. The apparatus is capable of removing fluids and subsurface sediments and slurry from bodies of fluid without resorting to prior art excavation or dredging apparatus and techniques. Use of the terms “fluid”, “sediment” and “slurry” are used interchangeably herein and are generally pumpable materials removable from the pond using the apparatus described herein. In embodiments “pumpable” materials are typically those which comprise water, solids such as sediment, silt and the like, and possibly other components which are typically lighter than water, such as plant matter, buoyant detritus and the like, and can be pumped by a pump, such as a progressing cavity (PC) pump.
Although apparatus embodiments disclosed herein are described in the context of land-based apparatus, apparatus can also be mounted on barge platforms which are sized and structured to provide sufficient stability so as to permit water-based remediations.
While suitable for use in a variety of constructed water bodies, including storm water ponds and industrial waste water ponds, apparatus embodiments are particularly suited for use in conjunction with NAUTILUS POND®, as disclosed in Applicant's issued U.S. Pat. No. 8,333,895, incorporated herein by reference in its entirety.
Embodiments disclosed herein provide systems for pond remediation wherein pond configuration enables sediment to accumulate therein in a portion of the pond, the sediment being removed therefrom as a liquidized slurry using apparatus disclosed herein. Thickening of the liquidized materials on site may further enable transport therefrom.
As is shown in
Remediation is often scheduled for off-season, such as in winter. The conventional remedy to pond sedimentation may include draining the pond 10 in order to provide access for excavating machines and conveyance vehicles 14 to remove and dispose of excavated sediment. The pond 10 may be drained into the municipal sewer system as drainage onto natural water ways during the winter months may not be permitted.
As shown in
As previously noted, the process can typically take 1 to 2 months for a conventional storm water pond 10 and the cost can be in the order of about $3M for each remediation performed periodically, such as about once every 10 to 20 years or so, on each pond 10. Disposal of drained water may be impractical due to government regulations and permits. Operations are often undertaken in the winter. Disposal of sediment is generally by spreading on other lands to dry or by thickening using specialized slurry dewatering equipment.
Extended-reach Embodiments
Concrete pump trucks are universally used and perceived as mechanisms suitable for one thing only: the delivery of concrete. Having reference to
As shown in
Applicant has determined there is typically no need for excavation-enabling equipment at a distal end 32 of the multi-articulated boom 22, given many subsurface pond sediments and other fine solids accumulations have a very constant, pumpable, slurry-like consistency. Further, given the extremely long moment arm of the multi-articulated boom 22, heavy appurtenances for mechanical excavation at the distal end 32 would be a disadvantage.
In embodiments, as shown in
As those of skill in the art will appreciate, when the multi-articulated boom 22 is extended, there is only a small tolerance for loading at the distal end 32 of the boom 22 without risk of tipping of the entire apparatus 26. Typically, conventional multi-articulated booms, when loaded with concrete, are designed to be able to withstand only a minimum loading at the boom's distal end 32, such as an operator steering the boom 22 for delivery of concrete therefrom.
Thus, in embodiments, to maintain stability of the extended-reach remediation apparatus 26, given the extended reach of the multi-articulated boom 22, Applicant believes the pump 40 must be sufficiently light-weight so as not to generate any significant load on the distal end 32 of the boom 22, over and above the pump's weight and that of the fluid being pumped. Thus, in embodiments, the pump 40 and any attachments thereto, imparts only nominal forces at the boom's distal end 32 so as to avoid threatening the stability of the apparatus 26. In embodiments, the nominal load is about 100 lbs or less.
As shown in
Apparatus and methods of pond remediation herein disclosed generally apply to removal of any fluid material having properties that one of skill in the art could reasonably define as “pumpable”, such as with a progressing cavity (PC) pump, which may or may not be operated as a positive displacement pump. Such fluid materials may include sand, silt and clay sediment slurry that accumulates at a bottom of water bodies 10, such as storm water management ponds.
Embodiments are discussed herein in the context of a PC pump 40, however as one of skill will appreciate the pump 40 can be any similarly capable pump technology. The PC pump 40 is capable of pumping the pumpable material through the conveyance conduit 42 in the boom 22 with sufficient pressure such that flexible or rigid extension pipes or conduit 54 attached to the proximal discharge end 45 thereof may be used for transport of the pumpable material to a local processing unit, to disposal, or to a truck/tanker loading area for remote transport therein.
With reference again to
By comparison, embodiments disclosed herein typically implement an hydraulic drive on the PC pump 40, permitting generation of significant pumping pressure, in addition to providing fine control over pumping flow rates, when enabled as a variable speed drive. As one of skill will understand, the pump 40 can be driven by an electric motor, pneumatics or any other power source that supports the objective of driving the lightweight pump 40.
As discussed above, and as shown in
In embodiments, other optional attachments are mounted to the boom 22 or to the pump 40. As shown in
Optionally, as shown in
In an embodiment as shown in
Other optional attachments include, but are not limited to, sensory probes, spray nozzles, motion or still cameras and light duty, static or actuated manipulators, grasping appurtenances or other custom designed attachments that enable effective and/or efficient removal of slurry according to the general or localized slurry's material properties. Further, combinations of attachments are contemplated, such as combining fluid-addition jets with a blender.
Large, heavy or unwieldy attachments that cannot safely be supported entirely by the fully extended multi-articulated boom 22 may be launched into the water body 10 and be manipulated by the boom 22, or attachments thereto, into the desired operating area.
One such example is a bottom skimmer attachment (not shown) operatively and fluidly connected to the pump intake 50, such as by a flexible hose. Such apparatus is generally too heavy to be supported above the water surface at the distal end of the boom 22 when the boom 22 is fully extended. The skimmer can however be initially deployed into the water body 10 in a stable configuration with the boom 22 only partially extended until the skimmer is supported substantially by the bottom of the water body 10. Thereafter, the skimmer is enabled to be gently dragged about the water body 10 using the boom 22 in the fully extended position without affecting the stability of the apparatus 26.
Alternatively, where heavy attachments intended for underwater operation are to be connected to the distal end 32 of the boom 22, unsafe boom loading forces can be significantly reduced, effectively minimized or eliminated entirely through buoyancy compensation strategies.
Alternatively, in embodiments, adjustments to the length of at least one or more of the boom segments 30 enables safe and stable operation of the apparatus 26 with the boom 22 fully extended. For example, the segment 30 at the distal end 32 of the boom 22 can be shortened, such as by a few metres, to reduce the weight of the distal end of the boom 22 for accommodating heavier attachments to be connected thereto without upsetting the stability of the apparatus.
Further, in embodiments, the apparatus 26 has a distal segment 30 which is configured to receive a variety of specially designed attachments which have an attachment length appropriate for the relative weight of the attachment so as not to challenge the stability of the apparatus 26 when the boom 22 is fully extended.
The utility of the extended-reach apparatus 26 extends to ecologically-sensitive areas, dams, access over embankments, roadside areas, vicinity of forestry roads and impassable areas. The extended-reach apparatus 26 may also be used to remediate spills.
Additional embodiments are focused on extreme mobility, such as may be the case when remediating remote, spill-contaminated water bodies 10 accessible by helicopter or other means of remote transport. The extended-reach apparatus 26 may comprise a lightweight multi-articulated boom 22 mounted on a high-maneuverability trailer or other form of mobile base 24, or may comprise on-site assembled apparatus 26 for assembly onto an in situ stationary support or base 24 from highly mobile components. The mobile components include the lightweight multi-articulated boom 22 and the pump 40 for mounting at the distal end 32 of the boom 22. The boom 22 is rotatably mounted to the in situ base 24 and provided the required functionality, but without the base 24 being mobile. Outrigger arms 52 of such a modular apparatus 26 could be attached to anchors embedded in the in situ base 24. Alternatively, ballast normally provided by the inherent mass of the mobile vehicle base 24 is added to each outrigger arm 52 in the form of either one or more massive objects or reservoirs filled with water, or some combination of ballasting strategies.
Thus, as one can see from the previous description, in embodiments, the base 24, to which the multi-articulated boom 22 is connected, can be mobile base 24, such as a self-propelled vehicle, a trailer for transport to a desired site or an in situ stationary support base 24 on which the apparatus 26, including at least the boom 22 and pump 40, can be assembled.
Pond Remediation Systems
While those of skill in the art will appreciate, there are a wide variety of scenarios in which embodiments disclosed herein could be applied, embodiments are described in the context of constructed water bodies 10. Such constructed water bodies 10 include storm water ponds, industrial process water ponds, tailings ponds such as are used in mining, oilsands and a variety of other industrial processes and the like.
Having reference again to
Alternatively, the conventional concrete slurry pump, or additional slurry-capable pumps are used to boost the slurry pressure in the conveyance conduit 42 if the pump 40 is unable to generate sufficient pressure to discharge the slurry therefrom particularly if the slurry is being delivered to a location remote from the apparatus 26.
As will be appreciated, an advantage of embodiments taught herein is reduced cost as individual components of the extended-reach apparatus 26 are mature products already on the market which can be readily retrofit as described above or otherwise modified for assembly. Alternatively, whilst the extended-reach apparatus 26 can advantageously be constructed by modification of existing equipment, a purpose-built apparatus 26 can also be constructed atop a transportable platform or self-propelled vehicle 24.
Having reference to
As shown in
Having reference to
Having reference to
Alternatively, in the case where the pond 10 is drained prior to remediation, embodiments of the mobile, extended-reach apparatus 26 can be deployed strategically within the pond perimeter 28 to permit access to substantially the entirety of the pond footprint. Temporary structures such as swamp mats or gravel road beds (not shown) can be used to support the apparatus 26 when driven into the drained pond 10. Alternatively, the base of the pond 10 may be constructed in such a manner as to provide a stable base to support the apparatus 26 for remediation from within the pond perimeter 28.
Having reference again to
Alternatively, as shown in
As one of skill will appreciate, local processing facilities 80, whether permanent or mobile, can be used. Such facilities 80 can, for example, permit significant dewatering of the recovered slurry, reducing the volume and thus the cost of transporting material to another location. The drier material is also more conveniently transported. Alternatively, dewatered slurry may be useful onsite in the construction of retrofit berms, equipment platforms within the pond perimeter, and the like. Where available, recovered slurry may be pumped to a local storage area for temporary or permanent disposal.
Pond Remediation Methods
In accordance with the embodiments of the extended-reach apparatus 26, methods for pond sediment remediation described herein are enabled.
As one of skill will understand, using embodiments of the apparatus 26 taught herein, remediation methods can be performed regardless whether the pond 10 is drained or not, or at what level the pond 10 is filled. Applicant believes that the extended-reach apparatus 26 is capable of removing high density pumpable sediment when the PC pump 40 is used. One such pumpable slurry comprises about 40% w/w solids. Further, the pump 40 is capable of removing materials from the water body 10 which are lighter than the water therein. Thus, any pumpable slurry formed of high density sediment and low density materials can be removed. In drained situations, or where pond levels are very low, advantageously the burden on waste disposal in downstream processing is reduced as the amount of water incorporated in the slurry is significantly reduced.
In embodiments, as shown in
Upon operation of the boom 22 and the pump 40, sediment and associated matter is pumped from the pond 10 and conveyed, via the slurry conveyance conduit 42 and extension 54 thereto, to disposal trucks 15 that may be stationed some distance away or to local processing facilities 80 or other desired locations. Through extension, retraction and rotation operations of the extendable, articulated boom 22, the slurry-capable pump 40 can be successively relocated about the pond 10 to the extent of the extended-reach boom 22, such as in a controlled pattern, to reduce remediation overlap and maximize efficiency. Minimum load is required to manipulate the pump 40 to each new location, the material through which the pump 40 is moved being of a slurry-like consistency.
Where the geo-location equipment 60 is used, location data indicative of remediation patterns can be logged and saved to a computer for record keeping and quality assurance reporting. Other electronic records may be made using conventional recording equipment such as cameras, depth monitors and other sensors, to further assist with management of the remediation.
If the size of the pond 10 is sufficiently large, after an operation to remove sediment from one portion of the pond 10, to the maximum practical reach of the extendable multi-articulated boom 22 is completed, the apparatus 26 is relocated to another location on the perimeter 28 or platform 70 located within the pond perimeter and the operation is repeated.
As shown in
In the case where the pond 10 has been drained, the extended-reach apparatus 26 can be relocated to temporary structures or roadways formed in the pond 10 or simply to a desired location of the bed of the pond 10, if so constructed to support the apparatus 26, and the operation as described is repeated.
In embodiments, the platforms 70 are sized about 12 m×about 15 m. As one of skill in the art will realize, the size of platforms 70 is illustrative only. The platforms 70 will vary in size depending on a number of factors, including the kind and size of the base 24 used, site access restrictions, site specific boom-reach requirements or other factors to be considered on a project by project basis.
This application claims the benefits, under 35 U.S.C. 119(e), of U.S. Provisional Application 61/822,998, filed May 14, 2013, and U.S. Provisional Application 61/836,365, filed Jun. 18, 2013, the subject matter of each being incorporated herein by reference in their entirety.
Number | Date | Country | |
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61822998 | May 2013 | US |