Patent Application
20230408149
In the process of designing and excavating large open pond containments for storage of brine solutions, seawater, potable water for human consumption, agriculture, and toxic reagents for minerals and oil/gas extraction, floating pond covers become an important remedial feature in overcoming evaporation losses to atmosphere, which in high deserts, can amount to 3 m or more annually to atmosphere in such exposed environments.
A simple concept in mitigating these lost resources utilizes a floating pond cover comprised of Hexagonal Cells wherein-but not limited to—19 plastic balls, working as an assemblage of spherical lenses are packed uniformly within a hexagonal frame to maximum 2-dimensional density, and wherein the fractional space between all adjacent balls is sealed by welding the interior assembly to a lattice structure composed of a single or double-layer plastic sheet of same material and nominal thickness as said balls and frame. Accordingly, >99.5% of pond areas are protected from evaporation loss, and more importantly, the floating pond cover becomes an effective solar collector, transforming the working media therein into a heat sink for, but not limited to, TES, sustainable salt and freshwater fisheries, chemical reagents for mining, and fracking in the oil patch, stored energy for power generation by Organic-Rankine-Cycle (ORC), and, heat recovery via LCZ in Salt-Gradient-Solar-Ponds (SGSP) for generating electric power and desalinating seawater in advanced multi-effect-distillation (MEDX) plants.
Images (11)
Classifications
Refracting lenses for thermal energy storage in SGSP evaporation control, and insulation for solar TES, potable water storage, chemical processing & metallurgy, wastewater treatment lagoons, aquaculture & mariculture.
This application claims benefit to Provisional Patent-Pending Application No. 63/366,681 filed Jun. 20, 2022, by John D. Walker, and entitled HEXLENS FLOATING SPHERICAL LENS COVERS FOR SOLAR PONDS AND LAGOONS, which is hereby incorporated by reference;
This application is further related to and incorporates by reference non-provisional application Ser. No 16/272,768, filed Feb. 11, 2019, now U.S. Pat. No. 10,987,609, and entitled POLAR-LINEAR-FRESNEL-CONCENTRATING SOLAR-THERMAL POWER AND DESALINATION PLANT, which is hereby incorporated by reference in its entirety, and U.S. patent application Ser. No. 16/951,345, of same title, filed Nov. 18, 2022, and U.S. Nonprovisional application Ser. No. 18/048,193, filed Oct. 20, 2022, the contents of each of which is incorporated by reference.
The present invention relates generally to field of thermal energy storage systems, and more particularly, to SGSP facilities wherein floating liners are emplaced to (1): reduce evaporation losses of water from the saltwater ponds, (2): maximize absorptance of incident beam solar irradiance, providing a thermal energy source to desalinate seawater and generate electricity using Polar-Linear-Fresnel-Concentrating (PLFC) or other CSP designs, and (3): recycle waste Brine solution from a nearby desalination plant utilizing heat transfer via heat exchangers immersed within the LCZ of said SGSP, providing latent heat energy for functions of seawater desalination and power generation (4) provide a floating insulation barrier thereby minimizing losses of thermal energy stored (TES) in the pond during nighttime hours or inclement weather.
SGSP and similar pond designs engineered at improvising TES and evaporation control, have, since the mid-20th century incorporated the use of large-area floating plastic liners composed of various woven fabrics and plastics, while shown to be effective are subject to photo-degradation and tearing under normal weather in most locals: UV radiation, moderate-heavy winds, snow and rain precipitation, and extreme ambient temperature swings, not to mention labor costs in regards to deployment and removal of said liners.
In response to this, several pond-cover systems have been developed by Industrial & Environmental Concepts, Inc. (IEC) and others, wherein lightweight individual balls or cells composed of recyclable HDPE or similar plastic are dispersed in quantities ranging from <10{circumflex over ( )}5 to >10{circumflex over ( )}7 cells, effectively covering ponds and lagoons in their entireties, thereby reducing pond-evaporation rates by >89% whilst primary function being absorptance of IR irradiance wherein heat transfer into the pond media serves multi-purpose functions of TES: examples of which include electrical power generation, seawater desalination, agriculture & aquaculture, regulating temperatures of reagents used and recycled in the mining industry, oil & gas extraction, light and heavy industries. A notable advantage of implementing the use of floating Cells for pond covers is the deployment of such Cells is less labor-intensive than that borne in laying out and welding single—or double LDPE membranes across large open containment areas.
One company, AWTT (Advanced Water Treatment Technologies), has an innovative solution to overcome some of the problems associated with large scale floating liners and more recently the floating balls cover systems, by using a simple geometric concept, wherein identical opaque HDPE hexagon floating Cells are distributed en masse; typical orders of magnitude ranging from ‘n’×10{circumflex over ( )}5 to >10{circumflex over ( )}7 Cells, on a pond or lagoon surface to point of overflow at the pond limits. As the floating hexagonal elements are dispersed across the surface, they tend to attract to one another by a very imperceptible gravitational force between Cells, wherein the equal length sides are the point of least resistance for forming a continuous floating field, or cover-liner with a virtually seamless appearance, resulting in an effective liner of up to 99% pond coverage.
Those of us growing up in the “Star-Trek” generation of the 1960's-‘70’s may recollect one of the earlier classics produced by the late Gene Roddenberry, wherein Captain Kirk was pitted in a fight to the death against a hilariously cuddly reptilian creature known as a Gorn, one of which outstanding anatomical features were a pair of enormous compound eyes. The following invention in part resembles these eyes, perhaps being yet another manifestation of the Sci-Fi author's imagination finding its way into real-world life situations, courtesy of an imaginary intelligent being from the 9th planet in the Tau Lacertae star system; celestial coordinates being R.A. 22 h 44 m/Dec. 45° N.
In the continuing quest worldwide for concentrated solar power (CSP) and seawater desalination systems, low-cost, energy efficient designs such as polar-linear-Fresnel-concentrators (PLFC) and advanced multi-effect-distillation (MEDX) plants respectively, are emerging technologies for producing electric power and fresh water. Thermal energy storage systems (TES), utilizing molten eutectic salts, generally composed of chlorides, nitrates and other inorganic salts in binary, ternary, and quaternary compounds, leading to the development of a single-temperature-thermal-energy storage system (SITTES), through which seawater is pumped through a plurality of lines and heat exchangers in the TES at various flow rates; accordingly, this SITTES is a multi-purpose facility, providing seawater working media to steam-cycle, organic-Rankine-cycle power generation using rotary-screw expanders, and low to moderate temperature MEDX desalination facilities.
Since the mid-20th century, an innovative TES method utilizing large-capacity (e.g., >300 m-square) salt-gradient-solar-ponds SGSP is increasingly applied in low-energy-input and low temperature desalination plants, operational examples found in Israel and other MENA nations, and the Southwestern United States. Typically, ponds are excavated using conventional earthmoving equipment, e.g., dozers and scrapers, by common cut-and-fill practice to several meters in depth, and by lining with impervious soils or clays, followed by overlining the entire excavated, graded and compacted earthworks by a heavy high-density-polyethylene (HDPE) or equivalent polymer liner; 80 mils (2 mm) in thickness. The MEDX desalination process necessarily reject waste-brine media (Brine) at a ratio of 2/3 : 1/3 distillate produced, with salinities exceeding 50 g/l typically being an upper value. In common current practice, the brine reject outflow from the desalination plant is either dispersed back into the sea using branched conduits spread out over a large area of seafloor to recycle the salts back to the sea in a diffused pattern, thereby reducing to a limited extent, environmental consequences to sea life.
In the arid MENA nations and desert Southwestern U.S., high ambient temperatures, low humidity, and strong or moderate wind velocities result in excessive evaporation rates, causing unacceptable waste of the water resource and excessive concentration of the Brine within the plurality of waste-ponds, resulting in supersaturation of said salts in the LCZ, thence excessive deposition of solid layers of chloride-precipitates on the pond floors. As noted in the Prior Art of this text, floating pond sheet liners are problematic in ponds of large dimensions.
It would be desirable to have a simple pond surface-liner comprised of individual cells using a polymer of robust properties, within a one—or two-layer (open- or closed) plastic body, specifically applied to a range of pond-storage containment objectives inside the greater CSP/desalination “Energy Park”, as well as in other applications, ranging from waste-water treatment, mining (metallurgy) process facilities, oil & gas drilling ponds, potable water for human consumption and agriculture.
Accordingly, there is need for a floating pond & lagoon cover-system that combine to mutual benefit the respective attributes of both IEC's Flotation Balls and AWTT's HEXPROTECT™ hexagonal floating cells into a simple design wherein a plurality of optical lenses formed by cutting in half- or lesser-fraction thereof, said Floatation Balls, and all of which are fabricated in mass by common plastic-molding methods from a specific polymer, wherein properties of albedo, absorptance to and refraction of beam solar irradiance at various wavelengths from the near-infrared through the visible light and I.R. regime are chosen in accordance with the principle function of the pond or lagoon: (1) TES storage in a plurality of SGSPs, wherein recycling of Brine reject media from a nearby MEDX facility enables furtherment of seawater distillation and electric power production augmented via direct solar irradiance and waste heat transfer amongst the plurality of Brine-SGSPs (2) maximize insulation properties of the liner by selecting a polymer of high reflectance, e.g., albedo >90%, thereby minimizing heat transfer from the Sun's energy into the pond; specifically applications where water temperatures must remain approximate to mean ambient air temperatures, such as potable water storage, and aquaculture industries (3) maximize absorptance of near-IR and visible light rays into the pond working media by utilizing transparent polymers suited to collection and refraction of the beam irradiance, such that sunlight penetrates into the three-thermocline zones of the SGSP; transferring and maintaining heat therein, accordingly, (4) maximize absorptance of IR irradiance into the SGSP, by utilizing a polymer of very low albedo e.g., ab<3%, or equivalent to “black velvet” surface of high absorptance; transferring heat therein and maintaining TES in the plurality of SGSPs, whilst precluding growths of algae and other photosynthetic flora within the pond working media, (5) minimize evaporation for all functions heretofore described, wherein the gap-ratio for the plurality of HEXLENS elements dispersed at maximum surface packing density in said pond or lagoon is <0.5%, approximating a 100%-objective accordingly, (6) protect birds and other wildlife from falling into and drowning into SGSPs, freshwater storage facilities, sewage ponds, or being poisoned by chemical reagents utilized in petroleum, mining, and industries.
For better understanding of the described devices and functions of the floating-spherical lens designs, reference should be made to the Detailed Description below, in conjunction with the following images, in which same reference numbers, and their respective locations in text refer to corresponding items throughout said figures.
Furthermore, by offsetting the top and base elements by a height of “H” cm truncates the hemispherical sections into a singular water-tight floatation cell, optimized to collection of beam solar irradiance such that there is minimal wasted solar collection area around the base of each lens due to interference from the totality of adjacent lens elements at low solar incident angles, and,
Thereby creating a floating lattice of plurality of Compound HEXLENS Cells providing all functions of (1) evaporation control, (2) TES, (3) insulation (4) solar energy absorption and heat transfer, or (5) solar energy rejection (maximizing albedo).
The floating-spherical-lens apparatuses (Cell) described herein for improvising TES, evaporation control, and insulating properties in SGSP, metallurgical processing, oil & gas drilling-fluids, potable freshwater containment, wastewater treatment systems, and aquaculture/mariculture water storage ponds and lagoons, described herein in eight embodiments are composed of low-cost, 100% recyclable plastics readily available on the market, and are selected on the desired attributes fitting a specific application. All Cell-designs share a commonalty in design by integrating a singular thin spherical convex lens on a center-axis of a hexagonal floatation body and are dispersed in plurality of pond environments in numbers sufficient to create a blanket-like layer atop the pond/lagoon surface in entirety. Cell features diverge from one another with respect to two defining physical properties of the polymer: (1) reflectance (albedo), (2) transparency or opacity to near-UV, visible and IR irradiance reaching Earth's surface, thereby being a versatile application wherein the intent of the pond cover designs range from maximum absorptance, thence transmittance, of solar energy into a TES system, to maximum reflectance, thence maximizing insulation of the pond media therein.
1. Modeling of Hexlens Cell Elements
1.1 Astronomy: Effect of Site Latitude on Beam Solar Irradiance
A large portion of desert regions on Earth facing critical water shortage are in the southern temperate (Mediterranean) and subtropics—equatorial zones of the inhabited continents, 40° N−23.5° N, and 23.5° N−0°, respectively, and their southern hemisphere counterparts, affecting the design of floating pond Cells. A Typical desert-site latitude of 30° N is used to illustrate the problem.
Given: A coastal site latitude of 30° N in Mexico Φ=30.00°
The winter-solstice 12 o'clock-noon altitude angle of 36.55° above the southern horizon is also very near to that value of where solar collection efficiency is about 60% of that at noon, due to apparent-thickness of Earth's atmosphere at low altitude angles (cosine-effect) becomes a factor in effectiveness of solar collection, during winter, and early a.m., late p.m. hours, in general, including other mitigating factors: light scattered to space, absorbed by water vapor, smoke and dust, etc.
1.2 Spherical Lens Optics Reference: Sfu.Ca/˜Gchapman/@89414u.Pdf
Given:
By comparison, for a glass pane comprised mainly of SiO2 n=1.4776
Determine: A ray trace model for a HEXLENS cell with spherical lens of radius r=15 cm, at latitude 36.55° N, at winter solstice; local solar time of 1200 hours.
Ray-trace model for spherical lens @ 30° N site latitude; winter solstice
Angle ABC on isosceles triangle inscribed in hemisphere: center axis-focus-ray 1,
1 HEXLENS Geometry
1.1 Hexprotect™ System
Hexagonal floating-cell pond cover systems produced by AWTT under the label Hexprotect™ are fabricated from opaque, black HDPE plastic, a highly durable material with expected lifetime of ˜25 years, in a plurality of pond environments and solutions. The Hexprotect™ cell upper surface consists of a modified hexagonal plane truncated by a symmetrical three-raised ridges and three-level triangular depressions, all extending radially from a center point of the cell body; in one iteration, a slightly raised dome about one-third width of the hexagonal cell at its minimum width, is featured. Each cell upper (atmosphere-facing) and lower (pond-contacting) surfaces are separated by hexagonally-arrayed rectangular strips, height of several centimeters, cell width-to-height ratio typically being 4.5-3.5/1; long-axis and short axis, respectively, and wherein interiors are either hollow, or packed with a foam material.
Generally, the surface area of a flat hexagon is:
S.A.=(3*(SQRT 3)/2)*t{circumflex over ( )}2, where:
t is the length of one of the six equal sides of said hexagon.
1.2 HEXLENS-COMPOUND-EYE System
HEXLENS-Compound-Eye floating cells are utilized in pond coverage liners wherein the attributes of insulation and evaporation control and maximum collection of solar irradiances reaching Earth's surface is needed for TES in solar ponds, chemical processing facilities, aquaculture farms, and waste-water treatment facilities.
HEXLENS-Compound-Eye floating cell covers are composed of, but not limited to: PET, HDPE, LDPE, and polycarbonate; each polymer being site-specific to the properties of maximum or minimum absorptance to beam solar irradiance, insulation, and chemical resistance to the solution, seawater, contaminants, or working-toxic-metallurgical reagents, e.g., NaCN— (aq) contained beneath the plurality of said HEXLENS Cells in a pond or lagoon.
HEXLENS-Compound-Eye: Open-Cell-Configuration (
Aside from material selection, a principal attribute of the HEXLENS-Compound-Eye Cell is a feature of a plurality of convex hemispherical lens formed by embedding and molding precisely, a plurality of balls (e.g., 19 spheres) horizontally within a horizontal plane the exact, or upper and basal to a singular or pair of plastic sheets of same thickness, thereby forming a water-tight assembly comprised of said 19 spheres, using common plastic fabrication processes, as in the manufacturing of plastic bottles. Being that one of the primary functions of the HEXLENS Cell-design is to maximize absorptance of, thence refraction of solar rays into the working pond media, the surface area of said totality of upper hemispheres (solar absorptance faces) of said 19 Cells is reduced at corresponding material cost savings from the original specification:
Application No.: 63/366,681, Docket No. WAL0103(PPA), wherein the area of the HEXLENS singular-hemisphere design is 1413.72 cm{circumflex over ( )}2.
Given: A circle wherein radius (rc) is inscribed exactly within hexagon of six equal sides (t) such that circumference touches center point (t/2) of each side of said hexagon.
Ahx=12*((0.5(rc/cos 30)*(rc/2))Ahx=799.4229 cm{circumflex over ( )}2
R{circumflex over ( )}2=(r3){circumflex over ( )}2+(r1){circumflex over ( )}2=19.8494 cm
Angle subtended from Z-axis to R=tan{circumflex over ( )}−1 (r1/R2)=49.0856°
Surface area of Sectional hemisphere-lens (cap) above base plane is
SA cap=π(r1{circumflex over ( )}2+h{circumflex over ( )}2)=719.4247 cm{circumflex over ( )}2
Checking by: SA=π(C{circumflex over ( )} 2/4+h{circumflex over ( )}2), where C=dia. cap base-plane; SA cap=719.4247 cm{circumflex over ( )}2
Which fits precisely within the 15 cm-dia. HEXLENS-base cell floatation device.
2 Properties
Physical properties of HEXLENS Cells designs, e.g., albedo, color, luster, transparency, opacity, determine degree to which solar radiation is refracted or reflected thru/from a floating HEXLENS Cell, optimizing absorptance and refraction, thence heat transfer into pond media, or minimize same in applications of maintaining pond temperatures equivalent to seasonal ambient at site-specific, respectively.
Various physical data for several polymers used in HEXLENS cells are tabulated herein:
3. Applications
COMPOUND-EYE-HEXLENS cells in floating pond liner systems are composed of one or all, but not limited to the family of plastics described, including the plurality of polymers numbered in hundreds which are not listed herein. Given that the selection process for a specific plastic is optimized for one or several functions, material used as well as geometry determines the HEXLENS cell ultimately suited to one or plurality of specific tasks.
3.1 Salt Gradient Solar Ponds (SGSP)
Transparent lenses are used in SGSP/TES ponds where solar collection is required throughout the economic solar-day for maximum energy-transfer into the pond working media, in situations wherein daily flow-thru of pond media to external devices is substantial, e.g., >10,000 m{circumflex over ( )}3/d; or in such saline environments wherein algal growths are insignificant wherein LCZ temperatures commonly attain 100° C. Natural analogues to these conditions are extant in various clear hot springs of Yellowstone, WY.
Opaque lenses, composed of black or dark-color plastic, of spherical hemisphere design or spherical caps are optimized for transfer of IR irradiance into SGSP/TES, wherein flow-thru or toxicity of the salt solutions is insufficient to preclude growth of algae or other plant biota.
3.2 Fresh Water Pond Storage
Opaque COMPOUND-EYE HEXLENS cells generally composed of, but not limited to, white or light color plastic, and of high albedo, (e.g., >0.90) thence insulation properties, are utilized in freshwater storage wherein temperatures are maintained approximate to seasonal ambient norms, thereby mitigating external parasitic power losses in heating or cooling the potable water recovered from desalination in reservoir-lagoon, whilst preventing growths of algae, spermatophyte plants, or controlling bacteria proliferation, and reducing evaporative losses. Exceptions are applicable in high latitudes wherein polymer material composed of black or other low albedo surface-color are utilized to control ice-buildup during the winter months.
3.3 Oil and Gas Fields
Saline media and other compounds mixed with water and injected into deep production boreholes to facilitate improved recovery of crude oil and natural gas, necessarily stored in containment lagoons, are covered with opaque COMPOUND-EYE HEXLENS cells to reduce evaporation rates, thence improve volumes available for recycling same media into nearby inactive wells for purpose of generating electric power via ORC utilizing rotary screw expanders, and fracking for enhanced recovery of oil/natural gas in fields nearing end of economic life. Accordingly, this liner design is also effective in preventing wildlife from entering said ponds by forming a visually unattractive setting for fowl and land animals to congregate.
3.4 Metallurgy
Mining gold and other metals entails storage of large volumes of toxic reagents in water, e.g., sodium cyanide solutions, in large open, lined containment ponds, for purpose of reuse; heap leaching of Au/Ag ores being a notable example. Typically, aqueous solutions of Na+CN− of pH ˜10.5 optimum are stored and recycled thru large ponds wherein concentration of said reagent is maintained at levels of 0.5 #-1.0 #NaCN/short-ton solution, the reaction with gold as follows:
2Au+4(NaCN)+O2+2H2O→2NaAu(CN)2+H2O2+2NaOH
Which is performed in distribution on the leach pads of crushed rock, in large volumes via sprinkler-lines laid out atop said leach pads, dissolving said elements for concentration in a secondary “pregnant pond” prior to adsorption of the gold-silver onto activated carbon columns for eventual recovery of concentrates therein by acidic-stripping, electrowinning and smelting stages, respectively. As the recovery process subjects both birds and land-animals to poisoning potential, and in high-latitude and high-altitude climates becomes less efficient due to icing and corresponding temperatures of solution approaching 0° C., standard operating procedure in numerous mine-sites is to deploy netting over the plurality of ponds to exclude wildlife from danger, and to maintain temperatures above freezing through friction-energy created via pumping thru the distribution lines infrastructure, and via external energy (heat) supplied through the mill site's power-plant. Alternatively, a concept utilizing HEXLENS cells comprised of black-opaque HDPE or LDPE are distributed en-masse throughout the totality of said pond areas in (1) absorbing direct solar irradiance in the IR spectral range, thereby transferring thermal energy to the Na+CN-solutions therein, and maintaining a working temperature well above ambient-air, (2) providing an effective insulation barrier, thereby creating limited TES within said ponds and supplementing the functions of Item(1), (3) creating an effective evaporation barrier, thence salvaging nearly 100% of water-bearing solutions in the process facility otherwise lost to evaporation over the pond surface areas (majority of evaporative losses in the heap leaching process are by far, beneath the the sprinkler lines on rock or crushed-ore-leach pads, thru evapotranspiration in the Au recovery process) in low humidity, arid and high ambient temperature climates, (4) providing an effective physical and visual deterrent to wildlife as part of a “greater-whole-design” (Items 1-4) which conventional netting alone does not attain.
3.5 Aquaculture and Mariculture
Transparent and translucent COMPOUND-EYE HEXLENS cells are applicable in small and large-scale sustainable fisheries, often incorporating pluralities of interconnected lagoons and ponds of many acres in size, the former being of function designed to maximize transmissivity of solar irradiance, thence thermal energy, into ponds which siting in mid or high latitudes necessitate fish species therein (e.g., tilapia) can proliferate during winter months. Accordingly, in colder climates HEXLENS-T cells with a fully or partial spherical-hemisphere-lens are distributed across the totality of the pond surfaces, each cellular element being of profile sufficient to maximize low-incident-angles solar-rays capture and absorptance, thence transfer of visible and IR rays into the pond media, creating (1) life sustaining temperatures to tilapia, anadromous ocean mullet, and other fresh or salt-water species of economic importance, (2) provide direct sunlight to ensure photosynthetic plants (which are food sources for both tilapia and mullet) are maintained in quantities necessary for oxygen production, thereby providing a locally grown food source for the fish in addition to those dispensed (e.g., soy-based pellets) by the farmer.
In subtropical to tropical climates, where pond temperatures naturally tend towards the ambient conditions under which the fish species are raised, the farmer is likely to choose a translucent plastic HEXLENS-D (diffuse) cell, thereby (1) preventing evaporative losses from the totality of the pond areas, whilst (2) precluding excessive irradiance from penetrating into the pond and overstressing the fish populations therein by excessive heating of the fresh or sea waters contained, with ensuing correspondingly high mortality rates, and (3) allowing visible light of the photosynthetically active regime (PAR)— about 400-800 nm— to penetrate the HEXLENS cell elements accordingly, with a diffuse polymer of opacity and color which filters out the more harmful rays, particularly in the far red-end and IR spectral classes; e.g., λ>730 nm.
3.6 Sewage and Wastewater
Mesophilic bacterium, being the primary anaerobic (no-oxygen-dependent) microbes utilized in digesting sewage, are most active in water temperatures ranging from 20°-50° C. (68°-122° F.); ideally, 25°-40° C. (70°-104° F.); (Hussein Abed Obaid Alisawi: Performance of Wastewater Treatment during Variable Temperature; 3/07/2020). Correspondingly, optimum conditions for aerobic (oxygen-dependent) microbial treatment of sewage ranges from 25°-35° C. (77°-95° F.); (Sara Heger, Ph.D.; May 8, 2017). In large population centers experiencing high-ambient summer temperatures (Cairo, Kuwait, Baghdad, New Delhi), ponds into which the sewage effluent are pumped into are covered with light-color opaque, COMPOUND-EYE HEXLENS-W spherical-cap cells wherein radius of curvature may exceed by 5 or 10-times (or more) than the radius of the individual hexagonal-base dimension, thence maximizing reflectance of incident solar rays, and, the individual cells also having been purged of all air and filled with an organic or inorganic foam packing, contributing to an insulating pond liner which attenuates excessive IR irradiance from transferring thermal energy, and thereby excessive heat, into said sewage pond, which otherwise is detrimental to the performance of sewage systems where either aerobic or anaerobic bacteria are utilized in digesting of the suspended solids and sludge-precipitate in the wastewater.
Conversely, in high latitudes and/or elevations experiencing low or moderate year-around temperatures, opaque COMPOUND-EYE HEXLENS cells comprised of black HDPE or LDPE-with or without insulating Foam-filling composed of same polymer-injected in totality of said Cells or translucent cells composed of same plastic, with or without an inert gas, filling, are dispersed over the totality of pond surfaces where practical, thence reducing the albedo of the major surface areas of pond-effluents not disrupted by the sewage agitation-pumps accordingly, to <0.05, and thereby providing a limited TES function in the pond by transmission of IR irradiance into the sewage media within, sustaining operating temperatures within the nominal range of 20-40° Celsius.
4. Economics
Following illustration shows the relative costs in materials a floating HEXLENS pond liner system composed of 60 mil HDPE incurs. The capital costs are shown to be obviously higher, than an equivalent sheet-liner of same material and thickness, but are offset by such extraneous factors being, but not limited to:
(1) Labor costs
(2) Recyclability
(3) Durability under extreme weather conditions
4.1 Material Costs
Calculate the comparative costs of applying the COMPOUND-EYE-HEXLENS floating pond cover as described in (
Assumptions
Given: A compound-eye-cell comprised of 19 cells packed into a hexagonal frame of minor axis length (R1) of: R1=15 cm; thence D1=30 cm across the short axis of hexagonal float.
Base area/Compound-Eye-Cell & 19 lenses=c+d 851.18 cm{circumflex over ( )}2; (mirror image-Skirt)
Tot. area/2-sided, invertible Compound-Eye-HEXLENS 2014.13 cm{circumflex over ( )}2
See
See
4.2 Advantages of a COMPOUND-EYE-HEXLENS Floating Pond System
Though capital costs of HEXLENS Cells in all configurations is obviously higher than conventional floating HDPE or other plastics, labor and maintenance issues quickly offset these expenditures, as described herein:
4.21: Labor Cost and Mechanical
Conventional floating-sheet liners of single or double-thickness are rolled out across the pond floor by groups of >10 individuals in most cases, tasked to manually pull and secure the pond cover, with mechanical assistance as needed. Prior to filling the pond with working media, the sheets are welded together using a high temperature “gun” on common seams to each other, thereby attaining final desired area coverage in manageable sections. Ropes and winching devices are used to both (1) stretch and secure the floating liners in final position to prevent damage from weather-related events, and (2) reel-in the liners for section replacement as necessary for planned or unplanned repairs and maintenance. Following installation and throughout economic life of the pond cover, the floating sheets are subject to minor or major damages caused by high winds, or heavy rains and ice storms.
COMPOUND-EYE-HEXLENS using the single-layer-lattice sheet design (
In further embodiment of design (
COMPOUND-EYE-HEXLENS cells of the twin-layer sheet design (
4.23: Recyclability and Disposal Options
Upon attaining end of economic life (<=25 years), COMPOUND-EYE-HEXLENS cells are simply scooped up by loaders and dump trucks from a decommissioned pond and crushed into bales for transport to a recycling facility where they are reprocessed into new products. Alternatively, said bales of polymer are transported to an organic waste incinerator with appropriate protection for particulate emissions and burned along with other similar consumables, generating electrical power accordingly.
| Number | Date | Country | |
|---|---|---|---|
| 63366681 | Jun 2022 | US |
