U.S. patent application number 09/802887 was filed with the patent office on 2001-08-09 for method and apparatus for economical solid-liquid separation in water-based solutions.
Invention is credited to Lumbreras, Manuel G..
Application Number | 20010011631 09/802887 |
Document ID | / |
Family ID | 23453964 |
Filed Date | 2001-08-09 |
United States Patent
Application |
20010011631 |
Kind Code |
A1 |
Lumbreras, Manuel G. |
August 9, 2001 |
Method and apparatus for economical solid-liquid separation in
water-based solutions
Abstract
An array of sonic hydraulic nozzles for injecting a mixture of
water with dissolved or suspended particulate into a chamber to
form a continuous spray of spherical droplets. Low pressure areas
form in the wakes of the droplets which promotes a phase change and
evaporation upon being submerged in heat vortices created along the
edges of the sonic shock waves. All dissolved and/or suspended
solid particles in the mixture precipitate from the spray upon the
vaporization of the water. Shortly thereafter, the particle-free
vapor re-condenses into a dense water mist of substantially pure
water, while releasing the excess heat captured in the evaporation
vortices. The water mist then is absorbed by nucleating screens
located above the nozzles. The screens concentrate the dense mist
into water streams through a channel running out of the apparatus.
The invention makes efficient use of the latent heat present in
ambient air to supply all phase change energy requirements to
affect a very low cost solid-liquid separation.
Inventors: |
Lumbreras, Manuel G.;
(Albuqueque, NM) |
Correspondence
Address: |
DYKEMA GOSSETT PLLC
FRANKLIN SQUARE, THIRD FLOOR WEST
1300 I STREET, NW
WASHINGTON
DC
20005
US
|
Family ID: |
23453964 |
Appl. No.: |
09/802887 |
Filed: |
March 12, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09802887 |
Mar 12, 2001 |
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09369067 |
Aug 5, 1999 |
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60096280 |
Aug 12, 1998 |
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Current U.S.
Class: |
203/10 ;
159/48.1; 203/40; 203/90; 210/737; 210/774 |
Current CPC
Class: |
B01D 1/16 20130101; B01D
5/0066 20130101; B01D 5/0003 20130101; B01D 3/06 20130101 |
Class at
Publication: |
203/10 ;
159/48.1; 203/90; 203/40; 210/737; 210/774 |
International
Class: |
C02F 001/04; B01D
003/00; B01D 001/16; B01D 001/18 |
Claims
I claim:
1. A method for separating solids dissolved or suspended in
water-based solutions and recuperating reusable water and the
solids comprising: injecting the solution into an
evaporating-condensing chamber and forming a dense spray of
droplets; whereby: the droplets subsequently evaporate into vapor,
thereby causing precipitation of the solids; and the vapor
subsequently condenses into a mist.
2. The method of claim 1, wherein the solution is at ambient
temperature.
3. The method of claim 1, wherein the evaporating-condensing
chamber is at ambient temperature.
4. The method of claim 1, wherein the evaporating-condensing
chamber is at ambient pressure.
5. The method of claim 1, further comprising collecting the mist
with a screen.
6. The method of claim 5, further comprising forming streams from
collected mist.
7. The method of claim 5, wherein the screen is positioned relative
to a flow direction of the solution at an angle ranging from 30 to
60 degrees.
8. The method of claim 5, wherein the screen is positioned 30 cm
from the nozzle.
9. The method of claim 5, wherein the screen is positioned such
that the screen optimally collects mist carried to the screen due
to momentum gained from said injecting.
10. The method of claim 1, wherein the evaporating-condensing
chamber is a mist making chamber.
11. The method of claim 1, wherein said injecting the solution
accelerates the solution to a velocity ranging between 200 and 300
meters per second.
12. The method of claim 1, wherein said injecting the solution is
substantially vertical.
13. The method of claim 1, wherein the droplets attain a size
ranging between 30 and 100 microns.
14. The method of claim 1, wherein the dense spray of liquid
droplets occurs substantially at 30 cm from the nozzle.
15. The method of claim 1, wherein the mist is substantially free
of solids and salts and has a density ranging between 12 and 18 kg
per cubic meter.
16. The method of claim 1, wherein said injecting is
continuous.
17. The method of claim 1, whereby the droplets do not accumulate
or remain in a suspension in the evaporating-condensing
chamber.
18. The method of claim 1, wherein the nozzle has an orifice with a
diameter of 0.75 to 1.25 mm.
19. The method of claim 1, wherein said injecting occurs at a rate
ranging between 0.20 to 1.5 liters per minute.
20. The method of claim 1, wherein the solution is selected from
seawater, brackish water and mineralized water with high salt
content.
21. The method of claim 1, whereby the solids separated have sizes
greater than 1 micron.
22. An apparatus for separating solids dissolved or suspended in
water-based solutions and recuperating reusable water and the
solids comprising a nozzle configured to generate a stream of
liquid droplets that evaporate, promoting precipitation of the
solids, then re-condense.
23. The apparatus of claim 22, said nozzle having an orifice with a
diameter ranging between 0.75 and 1.23 mm.
24. The apparatus of claim 22, said nozzle being adapted to eject
the stream at a rate ranging between 0.2 and 1.5 liters per
minute.
25. The apparatus of claim 22, said nozzle being adapted to eject
the stream at a rate ranging between 0 and 235 kg per hour.
26. The apparatus of claim 22, wherein said nozzle propels the
stream at a velocity ranging between 80 and 300 m/s.
27. The apparatus of claim 26, wherein the droplets have a size
ranging between 30 and 100 microns.
28. The apparatus of claim 22, further comprising an open-ended
evaporation-condensation chamber adapted to receive said
stream.
29. The apparatus of claim 22, further comprising a plurality of
other nozzles configured similar to said nozzle, said nozzle and
said other nozzles being disposed in concentric arrays.
30. The apparatus of claim 22, said nozzle being adapted to
generate a low-pressure region along a wake of the droplets.
31. The apparatus of claim 22, further comprising a screen
positioned relative to said nozzle for absorbing or condensing
mist.
32. The apparatus of claim 31, wherein said screen is constructed
from partially oriented yarn nylon polyamide.
33. The apparatus of claim 31, wherein said screen has microscopic
diabolo-type holes therein.
34. The apparatus of claim 31, further comprising a second screen
configured similar to said screen, said screen and said second
screen defining a predetermined distance.
35. The apparatus of claim 31, further comprising a second screen
configured similar to said screen, said screen and said second
screen defining a predetermined angle.
36. The apparatus of claim 35, said screen and said nozzle defining
a distance of 30 cm.
37. The apparatus of claim 35, wherein said screen has a total
surface area of 10 square meters.
38. The apparatus of claim 35, the predetermined angle ranging
between 30 and 60 degrees relative to a projection line of the
stream.
39. The apparatus of claim 31, further comprising a channel adapted
to receive fluid from said screen.
40. The apparatus of claim 22, further comprising a particle
distributor/collector beneath said nozzle for receiving
precipitated particles.
Description
REFERENCE TO EARLIER APPLICATION
[0001] This Application claims the benefit of U.S. Provisional
Application Ser. No. 60/096,280, filed Aug. 12, 1998, by Manuel G.
Lumbreras, entitled Technique and Apparatus for Very Economical
Solid-liquid Separation in Water-Based Compounds: The Sonic
Separation Still Process.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to liquid-solid separation. More
specifically, the invention relates to recovering useable water and
solids from salt and brackish water and water-based solutions.
[0004] 2. Discussion of Related Art
[0005] Many techniques have been developed for separating liquids
from solids in water-based compounds, such as where particles and
substances are dissolved in or suspended in water. Examples of such
compounds include solid and particulate matter dissolved mixed, or
in suspension in industrial and urban polluted waters, which may
contain dissolved metals, dissolved complex organics, solvents and
emulsions, radioactive contaminants and others. Other compounds
include naturally occurring sea and brackish waters, mineralized
waters, or man-made solutions used in industrial processes, food
processing, fossil fuels extraction, mineral extraction and others.
The present invention is suited for solid-liquid separation of all
the above, with very low capital and operating costs.
[0006] Current separation methods use a variety of techniques for
separating solids from their liquid bases. In general, the
techniques focus on recovery of the solid component, neglecting the
liquid. With respect to saline and contaminated waters, applied
techniques are purposed at rejecting solid particulate and
recovering the water base. In this latter case however, present
inefficient separation methods result in poor recovery and costly
processing, such as those that involve subjecting solutions to
chemical treatments and heating; evaporating the liquids through
boiling of the solutions and recovering some of the liquid through
condensation; forcing the liquids through high pressure devices;
and/or passing them through special membranes to retain some or all
of the molecules of the dissolved particles.
[0007] Current techniques for water production and treatment are
numerous. However,-- commercially implemented methods that are able
to obtain fresh water from saline and/or contaminated waters are
few, the main ones being distillation, reverse osmosis and
electrodyalisis. Although substantially different in approach, each
technique is fundamental flawed for efficient water recovery by
being very energy-intensive. This, in turn, causes high capital and
operating costs. Additionally, performances associated with each
technique tend to be very low: 25% to 40% for distillation; 30% to
50% for reverse osmosis; and lower still for electrodyalisis.
[0008] Most current water treatment systems for producing sizeable
amounts of potable water require substantial amounts of energy in
the form of heat and high pressures. As a result, the systems
require expensive process equipment such as pressure vessels, heat
exchangers and chemical digesters and processors. Major water
treatment systems also involve filtration, which requires the use
of expensive, perishable filtering organic membranes, thus are
fettered by high capital and operating costs, which results in
uneconomical recovery expenses.
[0009] This high-energy dependency also tends to result in
significantly low performance. If energy is equivalent of `work`,
the amount of work applied to a given separation process is
geometrically proportional to the amount of solids dissolved in the
solutions. A solution having high-solid contents requires more work
to separate the solids from the solution than a solution that has
less solid contents. The more efficient processes, in the best of
circumstances, require at least 50 joules per gram of solution
treated, which far exceeds the 2.5 joules per gram theoretically
needed for separating solids from its water base. This excess work
lowers performances and substantially increases process costs.
[0010] Some processes require high-temperature environments,
gaseous high-speed currents or compressed air to effect the
separation. Some processes involve drying by pulverizing heated
solutions; atomizing hot liquids; drying in fluid beds; filtering
through membranes; atomizing compressed air-liquid mixtures, etc.
However, each process for solid-liquid separation application has
serious limitations, especially in the separation of suspended or
dissolved particles in water solutions. A major limitation is the
requirement of an average of 2,000 joules per gram of solution
treated, mostly in the form of heat, electricity, high pressures or
a combination of the three.
[0011] In the separation of salts in sea and brackish waters, the
use of compressed air to drive and atomize the saline solutions
transfers the inefficiencies of a low performance energy-intensive
driver, such as compressed air, resulting in operating costs equal
or greater than other conventional desalination methods, such as
distillation. Moreover, as compressed air disperses and diffuses
the water vapor more than any other medium, the large masses of air
mixed with the vapor require large condensing cooling devices,
resulting in higher capital costs.
[0012] Spanish Patent No. ES 2,018,732, issued May 1, 1991, to M.
Lumbreras y Gimnez; and U.S. Pat. No. 5,207,928, issued May 4,
1994, to E. J. Lemer describe generating, with compressed air, a
stream of high-velocity saltwater droplets that vaporize without
being heated. Salt precipitates from the vaporizing liquid and is
recovered in a pan while the resulting water vapor is recovered by
showering the water vapor with liquid water. Saltwater is mixed
with compressed air. This mixture then is directed through an
indistinct pneumatic nozzle that atomizes the mixture in a chamber
where temperature and relative humidity are at ambient (room)
levels. The volume and effect of compressed air mixed with the
water and the high velocity of the mixture at the nozzle exit not
only limits the volume of water that can be recovered, but diffuses
the vapor inside the chamber by an entrained air mass that is
approximately 30 times larger at a short distance from the nozzle's
orifice. Diffusing water vapor into the chamber supersaturates the
ambient air. At a relative humidity of 100% or more, air is unable
to provide the energy necessary for evaporation, which impedes the
process. Also, large amounts of air induce the diffused vapor to
recombine with the separated salt particles.
[0013] U.S. Pat. No. 4,323,424, issued Apr. 6, 1982, to D. J.
Secunda et al. also addresses desalinization. However, both the
'424 and the '928 patents do not address the formation of
micron-sized, non-evaporated droplets that are indistinguishable
from vapor. This reduces the amount of fresh water produced. Fresh
water production is further complicated by the minute size of the
droplets, typically 1 to 10 microns in diameter. Once the droplets
evaporate, the resulting salt particles are of sub-micron size. For
example, a saline droplet of 1 micron in diameter, with an average
NaCl content of 3.5% by weight, as it is the case with seawater,
would precipitate a particle less than {fraction (1/50)}.sup.th of
one micron in diameter. According to Stokes' Velocity of
Sedimentation Law, particles up to 1 micron in diameter tend to
behave as molecules and remain suspended in the air for indefinite
periods, thus are able to recombine with the water vapor. For
brackish waters with salt content of 0.5% by weight or less,
processing is very difficult, as the solid salt particles would
have diameters smaller than 0.005 microns. Only droplets of 30
microns in diameter and up will shed salt particles large enough to
fall quickly by gravity. Thus, far from dropping to the bottom of
the chamber as these patents describe, salt particles derived from
droplets less than 30 microns in diameter will remain suspended in
the air for an undetermined amount of time, recombine with the
water vapor produced and be transported with the vapor to the
recovery chamber, driven by blower-produced air currents. Thus, the
collected liquid will be mostly saltwater.
[0014] Additionally, a substantial amount of vapor is produced by
the small water droplets that readily mixes with the large masses
of ambient (secondary) air entrained by the initial compressed
(primary) air at nozzle exit. This rapidly spreading vapor not only
cannot change into water mist, since the large masses of entrained
air impede condensation, but the vapor also fills the chamber
quickly. A chamber filled with vapor causes an entropy dilemma,
whereby the increase in overall humidity levels saturates the
chamber, exhausting the potential for evaporation of the secondary
air. This vapor will warm up and expand. This in turn disables the
remaining air from vaporizing additional droplets. Without heat
from the secondary air, the separation process stops.
[0015] Some of the techniques described counter these adverse
effects by generating an ambient air current in an upward and
oblique direction with a fan or blower at successive intervals from
the lower portion of the chamber. However, the air current crossing
the path of the suspended sub-micron salt particles fuses the salt
particles with expanded fresh water vapor. Further, the
intermittent blower also tends to recombine a portion of the
separated water with larger salt particles, falling to the bottom
of the chamber when the blower is off. The blower equipment also
increases capital and operating expenses, thus increasing the final
cost of any suitable water collected.
[0016] Although these techniques support a low air-water ratio of
1:10, the use of a compressor consumes over 18 kW/h per cubic meter
of fresh water produced. This high power consumption renders the
process non-competitive with current desalination techniques, such
as distillation, which uses less power.
[0017] In view of the above, producing inexpensive, reusable water
requires a separation process that derives a product with the least
possible work. Economically obtaining reusable water from
contaminated or sea/brackish waters ideally should separate the
contaminants and salts from their liquid bases at normalized or
standard room temperature and pressure (STP). A water recovery
process that operates at STP eliminates the need for
energy-intensive process engineering that otherwise would be needed
to drive the separation. Unfortunately, none of the foregoing
provides a method and apparatus for economical solid-liquid
separation in water base solutions that separates contaminants and
salts from their liquid bases at standard room temperature and
pressure. None of the aforementioned references, taken alone or in
combination, are seen as teaching or suggesting the presently
claimed Method and Apparatus for Economical Solid-Liquid Separation
in Water-Based Solutions.
SUMMARY OF THE INVENTION
[0018] The invention provides a method and an apparatus for
economical solid-liquid separation in water-based solutions that
separates contaminants and salts from their liquid bases at
standard room temperature and pressure. The invention provides an
affordable separation process that operates with low energy
requirements. The invention does not rely on a priori subjecting
the solutions to chemical treatment, evaporation and condensation,
such as in distillation. The invention does not rely on: high
pressures; mechanical or electrical filtering through membranes,
such as in reverse osmosis, electrodialysis, ultra-, micro- or
nano-filtration; or compressed air as a vehicle for impulsion and
atomizing the solutions. The invention provides a method and an
apparatus for purification and high-ratio recovery of reusable
waters without a posteriori subjecting the reusable waters to
chemical cleansing, chlorinating or fluoridation, without having to
re-pass the reusable waters through special membranes and without
having to pacify the reusable waters after recovery. The invention
provides a method and an apparatus for economical solid-liquid
separation in water-based solutions with which reusable and/or pure
water may be obtained at a fraction of the cost of present
capital-intensive water treatment methods. The invention provides a
method and an apparatus for the separation of dissolved solids from
contaminated waters and the recuperation of reusable water without
having to statically evaporate the solution, without having to add
or treat the solution with organic or inorganic matter or
chemicals, or to pass it through membranes. The invention provides
a method and an apparatus for separating the solids dissolved or in
suspension in contaminated waters and recuperating reusable water
with low uses of energy and capital. The invention provides a
method and an apparatus for the separation of salts from saline
waters and for recovering fresh water without having to heat the
saline waters to the boiling point until evaporation, without
cooling the fresh water in order to obtain large quantities of
same, without subjecting the liquids to high pressures and passing
the liquids through special membranes, and without the need for
compressed air to atomize the saline liquids. The invention
provides a method and an apparatus for desalting sea and brackish
waters and recovering fresh water with low use of capital and
energy. The invention provides a method and an apparatus for the
separation of solids from water-based liquids in industrial
processes, for recovering and/or recycling of the water used in the
processes, and for the recovery of the particles or solids
dissolved or in suspension in the liquids with a minimum use of
capital and energy. The invention provides a sonic hydraulic nozzle
system for the separation of solids in water-based solutions and
the recuperation of both reusable water and the dissolved solids,
using minimum amounts of capital and energy. The invention provides
improved elements and arrangements thereof, in an apparatus and
method for the purposes described which are inexpensive, dependable
and effective in accomplishing its intended purposes.
[0019] The invention exploits the super-efficient transference of
room air's latent heat to water-based solutions to effect
evaporation when the solutions are forced into low-pressure areas.
This heat transfer occurs when a feed is injected at high
velocities into a chamber where it evaporates upon impact with
still air. The transfer takes place in the high-energy,
low-pressure regions created by the high velocity jet solution,
evaporating all the water therein. While evaporating, the solid
contents present in the feed precipitate. As the vapor leaves the
low-pressure regions, the vapor re-condenses into substantially
pure water.
[0020] Utilizing the latent heat present in the ambient air for
evaporation of water feed at room temperature and local pressure
drastically reduces the energy needed to obtain a unit of fresh
water, dramatically enhancing performance and reducing both capital
and operating costs. Avoiding high pressures or compressed air and
producing water in its liquid form instead of vapor, eliminates
expensive process equipment, such as boilers, heat pumps, heat
exchangers, compressors, high-pressure pumps and membranes. The
corresponding reduction in the amount of process equipment reduces
substantially capital expenditures in a water treatment plant,
while obtaining significant savings on operating costs.
Additionally, as the invention promotes reusable water in liquid
form, the plant can use relatively compact devices, further
reducing capital costs. Finally, as the contaminated or saline
liquids are not chemically pre-treated or pre-heated, the water
produced does not require pacifying or cooling, does not need
chemical digesters and processors, and is ready for consumption.
The simplicity of processing equipment increases overall
performance, which can approach 90%.
[0021] The invention addresses the urgent need for alternative
economical ways of obtaining fresh water from saline waters, such
as sea and brackish waters. Food processing also benefits from the
present separation method because the invention eliminates costly
heated preparation processes. Also, cleaning oil spills,
contaminated ground water, urban water runoff and industrial waters
can benefit from the advent of a new, inexpensive technology for
solid-liquid separation.
[0022] An embodiment configured according to principles of the
invention includes a nozzle or an array of nozzles that, with a
moderate pressure of between 8 and 10 atmospheres, inject(s) the
water solutions to be cleaned of the dissolved and/or suspended
particles. The nozzle or nozzles accelerate(s) the particles to
sonic or subsonic velocities under controlled conditions. The
invention includes a mechanism for injecting the water-based
solutions through the nozzles. The invention also includes a
mechanism for recovery of the water and the particles dissolved or
in suspension. The invention provides a system or an array of
pressure manifolds that locate the nozzles in a horizontal axis and
a mechanism for impelling the solutions through the manifolds. The
invention provides a mechanism for avoiding the clogging of the
nozzle orifices.
[0023] These and other features of the invention will be
appreciated more readily in view of the drawings and detailed
description below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The invention is described in detail below with reference to
the following drawings, throughout which similar reference
characters denote corresponding features consistently, wherein:
[0025] FIG. 1 is a graphical representation of phase-change diagram
for water;
[0026] FIG. 2 is an environmental side perspective view of an
embodiment of a solid-liquid separation system constructed
according to principles of the invention FIG. 3 is an environmental
side perspective view of a commercial application of the embodiment
of FIG. 2;;
[0027] FIG. 4 is a top view of the embodiment of FIG. 2;
[0028] FIG. 5 is a vertical cross-sectional detail view of an
embodiment of a sonic hydraulic nozzle constructed according to
principles of the invention;
[0029] FIG. 6 is a horizontal cross-sectional detail view of the
embodiment of FIG. 5; and
[0030] FIG. 7 is a partial, top side exploded view of the
embodiment of FIG. 5.
DETAILED DESCRIPTION OF THE INVENTION
[0031] The invention is a method and an apparatus for economical
solid-liquid separation in water-based solutions that separates
solid contaminants from their liquid bases at standard room
temperature and pressure with minimal energy requirements.
[0032] For a pure liquid in equilibrium in its vapor phase, the
Clausius-Clapeyron equation and Gibbs phase rule can be used to
determine the water-vapor curve, or evaporation curve, as shown in
FIG. 1. If the temperature is above 0.098.degree. C., the
triple-point temperature, the only occurring phases are the liquid
and vapor phases. If all values of temperature T and pressure P are
allowed, the T, P plane is divided into three regions: solid,
liquid and vapor. These three regions define a liquid-solid curve,
a solid-vapor curve and a liquid-vapor curve, as shown. The three
curves coincide at the triple point. For water, this triple point
occurs at T=0.098.degree. C. and P=0.07 atm. The curves show that
water vapor can exist at very low temperatures, so long as pressure
is sufficiently low.
[0033] A liquid in a container at a pressure below the pressure of
water vapor in the container (0.04 atm at 30.degree. C.) will
vaporize very quickly and cool simultaneously as it does so. With
water, a zero value of "f" in the Gibbs phase rule, the evaporating
liquid derives the energy needed for evaporation from the
surrounding ambient air. Introducing high-velocity water/air
currents into the container at or near sonic speeds causes low
pressure areas, e.g. below 0.04 atm, to form in the wake of each
spherical droplet. This low pressure induces the droplets into a
hydrodynamic phase change. Aerodynamically, this phenomenon is
similar to the one that creates a region of low pressure under the
wing of a plane and provides lift.
[0034] Experiments done by the inventor using Phase Doppler
Interferometry and Particle Analyzer Anemometry analytical
instrumentation, revealed that water droplets in a stream moving at
sonic velocities inside an open-ended chamber tend to entrain each
other, thus reducing collective hydrodynamic surface and opposition
to friction. At velocities needed to overcome the sound barrier,
greater friction enhances the collection of heat, which coalesces
into vortices spinning from the surrounding air along the edge of
the shock waves. It is in these highly energetic vortices that the
droplets, already unstable and near the phase change point,
experience the heat transfer necessary to evaporate.
[0035] When all the solution has evaporated, the only remaining
substances from the traveling droplets are residual solid particles
which, unlike the water in the solution, cannot evaporate. Once
liquid-free, these solid particles fuse with each other, forced by
the kinetic energy generated in the entrainment zone, forming large
solid clusters, which precipitate out of the current by
gravity.
[0036] As the entrainment flow loses velocity, the compact
residue-free vapor travels a few milliseconds due to momentum,
leaving behind the low-pressure, turbulent heat-evaporating regions
and entering a normalized pressure environment of room air. It is
in this normal environment that the vapor experiences another fast
hydrodynamic phase change and condenses instantly into liquid mist.
As it condenses, the mist liberates heat, thus returning most of
the energy taken from the air and helping to maintain the energy
balance of the process indefinitely.
[0037] According to the foregoing, the method underlying the
invention is predicated on the following classical physics
postulates: (1) the injection of a water solution into a chamber,
where, at room temperature, the solution evaporates, forcing the
precipitation of the impurities dissolved or suspended in the
water; (2) the immediate condensation of the vapor into liquid
water mist; (3) the subsequent condensation of the mist into
running water; and (4) the fresh water departing the apparatus by
gravity.
[0038] Referring to FIGS. 2 and 3, an embodiment configured
according to principles of the invention includes sonic nozzles 10
capable of impelling liquid solutions without compressed air. The
sonic nozzles 10 accelerate the solutions from 80 to 300 m/s in
order to develop a jet stream of liquid droplets.
[0039] The solution is injected into a non-pressurized, open-ended
evaporation-condensation chamber 20 such that ejection is
substantially vertical. Vertical ejection aids in breaking the
solution into droplets. Ideally, the droplets attain a size no
smaller than 30 microns and no larger than 100 microns in diameter.
This size range promotes complete evaporation of the solution and
discourages recombination of the solid particles with the
evaporated water.
[0040] The evaporation-condensation chamber 20 has an open-ended
top and bottom. The evaporation-condensation chamber 20 may be
assembled from a fiberglass cylinder encased in a steel
container.
[0041] An injection pump 30 injects feed solution through a pipe 32
and manifold 34 into the evaporation-condensation chamber 20
through the battery of sonic nozzles 10. Preferably, the nozzles 10
are disposed in concentric circles in a horizontal plane, as shown
in FIG. 3. The solution flows vertically from the nozzle orifices
into the chamber 20 at sufficient velocity to break the liquid
solution into small droplets and create low-pressure regions along
the wake of the droplets.
[0042] The invention also includes nucleating screens 40 made of
Partially Oriented Yarn (POY) nylon polyamide. POY permits
texturing the resultant material with microscopic diabolo-type
holes running the length of the screens 40 and accepts etched
channels to nucleate the mist. POY has a high absorbing capacity
for water mist, thus facilitates rapid nucleation of the mist and
its transformation into running streams of fresh water, without
washing the mist with artificially generated showers. The screens
40 are positioned, at angles to each other, at intervals long the
length of the chamber 20 so as to capture all mist created in the
evaporation-condensation chamber 20, and impede any mist from
escaping from the chamber 20.
[0043] In the interior of the chamber 20, all of the liquid in the
front line droplets rapidly evaporates at a short height, e.g. 15
to 30 cm, from each nozzle orifice, within a few milliseconds. The
jets' momentum carries the instantly evaporated water masses into
re-condensing particle-free droplets and a dense water mist, which
quickly approaches and is absorbed by the nucleating screens. This
absorption is accelerated by the upward vertical draft generated
both by the temperature differential generated by the
evaporation-condensation process and the pressure differential
created by entry of air at the bottom and egress of the air from
the top of the chamber. The fresh water mist adheres to the
water-nucleating screens, which have lower edges that rest in a
cylinder channel 25 encircling the evaporation-condensation chamber
20. When saturated with water, the screens 40 swiftly shed the mist
into the channel 25 in running streams. The channel 25 flushes the
water outside of the apparatus by gravity through a fresh water
exit 27. The water is received in a collecting water tank or water
main.
[0044] During evaporation of the solution, particles dissolved in
the solution, but not evaporated, precipitate and drop by gravity
between the nozzles into a cyclone or particle
distributor/collector 50. The particle distributor/collector 50
deposits the particles into a receptacle 52. From the receptacle
52, the particles either are removed by a conveyor belt or
accumulate in a removable container to be disposed of
periodically.
[0045] Referring to FIG. 4, the battery of nozzles 10 are arranged
along concentric arrays of manifolds 15 through which the solution
is distributed to the nozzles 10. The nozzles 10 point vertically
in such a manner as to deliver the liquid, create the droplets, and
urge the ensuing vapor and condensed water mist toward the
nucleating screens. The nozzles have orifices with diameters
ranging between 0.75 and 1.23 mm. The nozzles are capable of
injecting between 0.2 and 1.5 liters per minute of solution with
dissolved or suspended particles. The nozzles produce spherical
droplets with diameters between 30 and 80 microns.
[0046] The outside ambient air entering the apparatus provides more
than enough energy for the feed solution phase changes.
Additionally, the upward draft of the air through the chamber 20
contributes to drawing the water mist into the nucleating screens
40. Thus, the process is continuous and self-sufficient, without
need of supplementary power-driven equipment.
[0047] A preferred method for producing liquid-droplets for
evaporation and subsequent condensation entails: the generation of
dense fresh water mist at approximately 30 cm from the nozzle
orifices. The mist should be free of particles or solids and have a
density between 12 to 18 kg per cubic meter of mist. Generation of
the dense fresh water mist should be continuous and non-pulsating,
yet discourage accumulating a suspension of fresh water droplets
which would supersaturate of the evaporation-condensation area. The
fresh water mist should saturate the condensation area with a
density of 1 to 3 kg of mist per square meter per second, but
without accumulations, until all of mist has been absorbed by the
nucleating screens. The mist then combines to form running
water.
[0048] The method also provides for separation of the solid
particles dissolved or suspended in the liquid, and allowing the
particles to drop by gravity from the evaporation-condensation
area, through separations between nozzles in the manifold. The
particles are evacuated without recombining with the vapor or the
fresh water mist.
[0049] Another embodiment of the invention provides for recovering
the fresh water mist by locating layers of water-collecting screens
40 in a serial or staggered manner. The screens 40 are positioned
at angles with one another, the angles being between 30 and 60
degrees with respect the main cylinder of the apparatus or flow
direction. The edges of the screens rest in the encircling water
channel 25, just inside the evaporation-condensation chamber 20.
The first screen 40 is positioned approximately 30 cm from the
nozzle orifices and has a total surface area of approximately 10
square meters. Recovery of the fresh water from the mist in the
collecting screens occurs by virtue of the momentum caused by the
ejection jet and does not require artificially generated air
currents in order to transport the mist outside of the
evaporation-condensation area. Fresh water from the collecting
screens 40 is delivered into the circular water channel 25
surrounding the evaporation-condensation area, which transports the
water outside of the apparatus, by gravity.
[0050] A preferred embodiment of a water treatment plant configured
according to principles of the invention produce 15 to 20 cubic
meters per day of a treated solution, depending on particulate
concentration and climatic conditions. The nozzles 10 should be
situated in manifold arrays to create a mist suspension of 0.06
liters per second/per nozzle with a density between 10 to 18 kg per
cubic meter of mist. The shape and height of the cylindrical
chamber 20 should be configured to circulate sufficient masses of
ambient air to supply the necessary energy to effect the phase
changes necessary for the separation process and the resultant
internal temperature differential due to the phase changes. The
sonic nozzles 10 should be able to propel 0.40 liters per minute of
solution per nozzle unit and create droplets having diameters of 30
to 100 microns. Each nozzle orifice should have a diameter between
0.75 and 1.5-mm. The nozzles should be arranged so as to allow for
the creation of clumps of particles fused together, separated from
the vapor, which drop by gravity outside of the liquid jets,
without interfering in the upward motion of the jets, and without
recombining with the liquid.
[0051] Referring to FIGS. 5 and 6, a nozzle 10 configured according
to principles of the invention provides a sonic effect, a
relatively monodisperse droplet size and has a flow capacity of
approximately zero to 235 kg per hour. The nozzle 10 receives
solutions to be treated through the body of the nozzle through a
narrow channel K. The channel K expands into a cone-shaped chamber
I. From the chamber I, the solution passes through a
turbulent-making area M. The turbulent making area provides a
serrated surface generally orthogonal to the flow direction. Since
expansion takes place in an inverse current flow, liquid is
accelerated until it exits through orifice B. The orifice B has an
area that is a fraction of the size of the base diameter of the
cone.
[0052] Refrerring also to FIG. 7, through orifice C the liquid is
further accelerated. Upon exiting at orifice C, the pressure
differential with ambient environment produces a vacuum effect,
which draws a column of exterior air through orifices J and D. At
the exit of this column of air is an expansion ring G of less than
0.5 mm thickness which coincides with another expansion ring that
is approximately 3.5 mm thick and has a smaller diameter size than
orifice C. The rushing liquid and drawn air are mixed in the volume
defined within the expansion ring, building substantial pressure
before evacuating through the orifice C.
[0053] The mixture flows through an expanding chamber, between
apertures C to B, the sides of which define an angle N relative to
the flow direction. The angle N is a multiple of the liquid
exit-orifice angle inside the nozzle chamber and the liquid-air
mixture exit orifice angle. The aspired air mixed in the volume
defined by the expansion ring further accelerates the liquid and
induces turbulence in the near-vacuum environment near the nozzle
orifice L. The initial liquid pressure at the injection pump head,
plus the liquid pressure differential at the exit and the orifice
angle all contribute to accelerate the liquid to the point that, at
nozzle exit E, the liquid accelerates to sonic velocity.
[0054] Because the liquid exits the nozzle containing a minimum
amount of air, there is little fractionating of the liquid,
resulting in a monodisperse spectrum of droplets with controllable
size ranges related to the pressure of the injected solution.
[0055] The dimensions for a preferred embodiment of the nozzle 10
are substantially as follows:
1 A B C D E F G H I J K L M Diameter -- .735 .076 .046 .104 .484
.735 .464 .092 .234 Length/ 1718 .015 .076 .140 .515 Height Angle
in 90 110 45
[0056] The invention is not limited to the foregoing, but
encompasses all improvements and substitutions consistent with the
principles of the invention.
* * * * *