Advances In Desalination:
The Aul EGD Process
by Robert A.
Nelson
Electro-Gravitational Desalination ( EGD
)
A simple method of desalting
ocean water now exists which uses no external energy, and
produces electrical power at the same time! This revolutionary
process, called Electro-Gravitational Desalination (EGD),
makes it possible to recover as potable water more than 80% of
the saline or brackish water treated with the process. It also
produces at least enough electrical power to operate pumps to
keep the system flowing.
According to Albert Aul
(email inJanuary 2003), the Aul EGD process is currently
"dormant" because:
(1) "It was discovered that
the gap between anode and cathode had to be maintained at 0.25
inches for the process to oeprate. This created a design and
maintenance problem that limited the cost effectiveness of any
equipment built, regardless of size.
(2) " Marine
micro-organisms, such as gallionella, attacked copper
voraciously: numerous test units were literally detroyed by
them (chlorine does not appear to kill such organisms.
(3) "Most importantly, the
development activity ran out of funds. Given the above
described difficulties, a prolonged and expensive effort to
overcome them was not to the best interest of the funding
sources, and the work was abandoned."
Accordingly, the following
information is presented with the suggestion that only the
construction of a 1-gpd unit be attempted as a survival
apparatus that can be cleaned manually, without concern for
cost efficiency.
As human population
increases, fresh water resources are being depleted rapidly
due to waste, pollution, declining water tables, and
subsequent salting-up (increased concentrations of dissolved
minerals) of ground water, rivers, etc.. This makes
desalination increasingly necessary and cost-competitive with
the transportation of fresh water over long distances. Some
900 desalination plants with a total capacity of almost 300
million gallons/day are located throughout the world today.
Several processes have been
developed for desalination of water. Distillation is the
oldest and most common desalination process in use. Other
processes include: solvent extraction, electro-dialysis,
reverse osmosis, propane extraction, freezing, and
ion-exchange systems. All of these methods consume large
amounts of energy that alters the economics of desalination.
But the cost of transporting fresh water is increasing, so
desalination remains cost-competitive.
The new method of
Electro-Gravitational Desalination (EGD) is the discovery of
Albert H. Aul, who received U.S Patent #
3,474,014(Cl. 205-150) and several foreign patents
for his invention.
Electronic coagulation of
saline solutions has been developed since the early 1940s, but
such systems employ strong direct current. The Aul EGD system
requires no externally applied energy; rather, it generates
its own electrical power. It is in effect a salt-water battery
in addition to its desalination applications. Aul explains EGD
as follows:
"The principle upon which
EGD is based is galvanic to the extent that a 'primary' (not
rechargeable), low-power battery is galvanic. In any EGD
system (as in any battery), each cell contains two electrodes:
a copper anode and an aluminum cathode. The electrolyte
(dilute sulfuric acid in a storage battery, but only sea water
in an EGD unit) 'connects' the electrodes at one end, but in
order to complete an electric circuit it must be connected at
the other end as well, and in order not to deplete the
'battery very quickly (as would be the case if the electrodes
were connected only with a wire and no 'resistance' --- called
a short-circuit), some resistance (or 'load') must be added,
such as lights, or a motor or other devices, in the connection
between the electrodes at the other end.
"Electricity is produced by
chemical action, and in the case of an EGD unit using copper
anodes and aluminum cathodes, oxygen and aluminum are the
materials that react with each other, and hydrogen is the
catalyst. In plain terms, a catalyst is a substance that
causes other substances to become unstable and recombine to
become stable. Aluminum and oxygen, when in contact, without
the presence of hydrogen, will remain independent and stable,
but in the presence of hydrogen will combine, releasing
electrons. Water is hydrogen and oxygen. When in EGD the
aluminum and oxygen combine, the hydrogen goes off mostly as a
gas.
"In the EGD systems as
described, no other electrode-metal reactions with materials
in the water have been measured or observed. However, with the
electrical field that exists, the particles of salts
(chlorine, sodium, bromine, magnesium, and every other
substance attached to the water molecules) become attracted to
the electrodes. The field generated by the EGD system is
stronger than the field that holds these particles to the
water molecules; thus the copper anode electrode attracts the
positively charged particles (anions), and the aluminum
electrode attracts the negatively charged particles (cations),
the particles or ions being molecules too, but composed of
only atoms that each represents. Sea water, for example does
not contain sodium chloride (table salt); chlorine and sodium
ions are individually attached to the water molecule. In
nature they only combine when the water molecule has been
evaporated away, and there is no 'occupied' water molecule to
become attached to. In EGD, these ions become detached because
of the electrical field.
"In EGD the field strength
is really unimportant, as long as a field exists. We make up
for that lack of a field strength of a copper/aluminum EGD
device by flowing the water through a large number of cells.
The number of cells and the flow rate dictates the rate of
desalting and the amount of saline material remaining in the
water after it has gone through EGD processing. There are
limitations on flow rate for each design, and there are
minimum numbers of cells for each design. The maximum number
of cells is dictated by the builder of the EGD devices; there
is a point in each design where the amount of matter removed
in relation to the cost of the cells is so small that it
becomes impractical to have the extra cells.
"As the materials (ions of
various salts) accumulate adjacent to the electrode surfaces,
and the water's laminar flow downward along the electrode
surfaces carry the ions out of the field, much of the ion
material becomes reattached to water molecules not in the
field (they redissolve), forming a dense brine. That water
from which the saline ions have migrated, now is unburdened
and less dense than the saline water. The desalinated
(desalted) water occurs in the center of the gap between the
electrodes and is "bouyed" up by the denser saline water
below, so that the desalted quantity is to be found at the
top, center-of-gap location of each cell.
"Only about 30% of the EGD
process depends on chemical reactions. For this reason the
initial urge of technical persons to analyze the process using
conventional electro-chemical thermal balance equations should
be subdued. The well-known phenomena of the behavior of matter
ions in solution between a non-reactive cathode and
non-reactive anode, more closely represents the facts, except
that the electrolyte is not an electroplating medium, and that
the system is galvanically disposed by a minimum reaction of
cathode (aluminum) and electrolyte-borne oxygen/hydrogen,
rather than with applied energy from an external source."
Of the 30% of the EGD
process that includes chemical reactions, many of the
materials are released as gases such as hydrogen, chlorine,
and others. Hydrogen and chlorine also recombine to form
hydrogen chloride, which reacts with calcium carbonate to
produce precipitant calcium chloride and free hydrogen. Some
of the liberated ions of sodium, calcium and magnesium
recombine with the carbonate radicals disrupted from calcium
carbonate and form respective carbonates and hydroxides. (Figure 1)
Because most of the salts
are removed by EGD rather than by reducing the electrodes, the
electrodes last a very long time and require only periodic
cleaning. The cathode reduction rate is calculated at 0.0013
oz. avoir. of aluminum hydroxide for each 100 gallons of water
desalinated. The average value of current produced is 0.000022
amp/sq. in. of cathode surface in contact with saline water
being processed.
Albert Aul describes a very
simple model that can be constructed to demonstrate the
principle of EGD:
"Two metal plates, one of
aluminum and one of copper, approximately 2" x 3" x 1/16"
thick, are drilled with two 1/4" diameter holes in the top
corners of both plates. Insert wood dowels through the holes
so as to support the plates about 1/2" apart in a wide-mouthed
jar of about 3-pint capacity. Connect the electrode plates
with a short piece (about 5") of insulated wire, to both ends
of which are soldered alligator clips. Fill the jar with
ordinary tap water in which is dissolved about 1/2 gram of
table salt. Then add a few milligrams of thymol blue pH
indicator. Adjust the pH with a minute amount of very dilute
acetic acid (vinegar) and sodium hydroxide (lye) until the
water turns an orange color. Any additional acetic acid will
increase the pH and produce a bright red color. Additional lye
will change the color to clear yellow. The apparatus now is
complete."
The two plates are
electrically connected using the wire and clips, thereby
establishing a galvanic cell of the type described by Albert
Aul. After several minutes a noticeable change becomes
apparent: the copper plate becomes blanketed with a thin layer
of dark red color, and the aluminum plate is covered with a
thin yellow layer. As the copper anode attracts positive ions
and decreases the pH in its area, the indicator turns bright
red in that region. The pH increases around the aluminum
cathode and the indicator changes to a yellow color in that
zone as the negative hydroxyl ions accumulate there. Within
ten minutes the colored layers become about 1/16" thick on
each side of the metal plates. Then streams of red and yellow
fluid can be seen coming off the bottom of the metal plates
and extending to the bottom of the jar. As the operation
continues, the colored zones increase at the bottom of the
jar. After several hours of operation, small flecks of
aluminum hydroxide form on the aluminum cathode.
"The indicator changes color
because the positively charged (electron-deficient) hydrogen
atoms are attracted to the copper anode, and the negatively
charged hydroxyl ions are attracted to the aluminum cathode.
In the same manner, the dissociated salts yield positive ions
of sodium, magnesium, and calcium that are attracted to the
copper anodes while the anions of chlorine, carbonates, and
hydroxides are attracted to the aluminum cathode. As the
solution of ions increases near the plates they establish a
gravitational convection flow in which the denser fluid layers
containing higher concentrations of salt ions settle to the
bottom of the jar, leaving the fluid zone between the
electrode plates depleted of dissolved salts, i.e.,
desalinated."
The construction of a
practical EGD system requires certain constraints. For
instance, the gap between the aluminum and copper electrodes
must be 1/4", with only a narrow margin for variation. If the
gap is too narrow, it short-circuits as chains of aluminum
hydroxide build up and bridge between the electrodes. If the
gap is too wide, the electrochemical potential is too low and
insufficient to the electrochemical reaction threshold. Also
the water must enter the system within the electrode zone, not
below it, as indicated in Figure 2.
The following is a description of a preferred embodiment of
the Aul EGD process:
"Four tubular copper anode
containers were connected in such a manner as to permit saline
water to be introduced a distance from the bottom of one tube,
then permitted to flow out of the top of that tube into the
next tube, where the inlet was in the identical location of
the first, and so on for all four tubes. The distance from the
bottom of the containers to the inlets was sufficient not to
impede the deposition of the precipitants nor cause the
incoming water to be mixed with the precipitants.
"Tubular aluminum cathode
elements were then suspended into the tubular anode
containers. The cathodes were connected together by... an
insulated wire. The anodes were connected together by an
insulated wire, and then connected to one side of a meter
calibrated to be read in milliamperes. The cathodes were
connected to an electrical resistance of 10 ohms. The
electrical resistance was connected to the other side of the
ammeter.
"The axes of the copper
anode containers and the aluminum cathodes were coaxial and
oriented perpendicular with the earth's surface. The total
capacity of the system was measured at 2.7 gallons of water.
At the bottom of each container a stopcock was provided for
the removal of precipitants.
"Saline water was introduced
and permitted to flow continually through the system at a rate
of 2.7 gal./day. the water was tested. The total dissolved and
solid saline materials were 36,000 ppm of water before the
introduction into the process, and only 370 ppm after ejection
from the system, indicating about 99% desalination. The
precipitants were removed as a dense brine which measured
104,000 ppm of suspended solids for each 2.7 gallons
processed."
After sea water containing
about 15,000 ppm of dissolved or suspended solids has passed
through a series of about a dozen Aul EGD cells, its saline
content has been reduced to about 250 ppm. This is good
drinking water. If the water is used for agricultural
purposes, a higher saline content is acceptable.
In 1965, Louis Shaffer,
chief of the Reclamation Bureau's Division of Hydrology at San
Bernardino, tested an Aul EGD plant which processed water from
the Salton Sea to yield desalted water about equal in quality
to kitchen tap water in San Bernardino. Shaffer said:
"It's a revolutionary
approach to the age-old problem of converting sea water to
fresh water in the arid regions of the world."
The Aul EGD process has
become a dormant technology since the death of the inventor.
This elegant technology now awaits further development, and a
thirsty society awaits its implementation. Following herewith
are Albert Aul's US Patent # 3,474,014 and construction plans
for EGD units with 1 gallon/day and 100 gpd capacity. As
stated at the beginning of this report, only the construction
of a 1-gpd unit can be recommended as a survival apparatus...
References:
1. Aul, Albert H.: U.S
Patent # 3,474,014 (Cl. 204-150), 21 October 1969;
"Electro-Gravitational Desalination of Saline Water"
2. Stuart, Fred E.:
"Electronic Coagulation"; Public Works (April 1947),
pp. 27-36.
3. Murphy, George W.,
& Batzer, David: "Apparatus for Studying
Electro-Gravitational Separations"; J. Electrochem Soc.
(December 1952), pp. 520-526.
4. Luce, Capt. J.D.: U.S.
Coast
Guard Trip Report (12 January 1966):"Visit
to General Marine Technology Corp."
5. U.S. Bureau of
Reclamation Report (23 April1965/3 May 1965):"U.S.
Salinity Lab Water, Untreated & Desalinated Salton Sea
Water, & Sea Water Comparison with City of San Bernardino
Water."
6. San Francisco
Chronicle; 5 July,1965
7. Hoblscher, Prof.
Erwin C.: "Analysis of Desalination Process Proposed by
Mr. Albert Aul"; Supplementary Report (17
January 1969).
Foreign Patents Issued to
Albert Aul for EGD:
Australia # 435,486
(62,235/69), 10 May 1973.
Belgium # 740,506 (20 October
1969).
Canada #909,716 (12 September
1972).
France # 2,063,974
(69-35684), 17 October 1969).
Great Britain # 1,271,829 (20
October 1969).
Israel # 33,147 (28 September
1972).
Italy # 1,045,106 (10 May
1980).
Japan #792,258.
Sweden # 343,282 (15 June
1972).
Figure 1:
ElectroGravitational Desalination ~
Figure 2: EGD Cell ~
U.S.
Patent
#
3,474,014
Electrogravitational
Desalination of Water
U.S. Cl. 204-150 (Oct.
21, 1969)
Albert H. Aul
Abstract:
Electrogravitational
method of desalination of salt water using two dissimilar
metal electrodes connected externally which form a galvanic
couple creating current flow through the system. Portions of
salts that are attracted to the electrodes establish
concentrated areas of higher density that settle to the
bottom of container whereby the solution removed from the
bottom is of a greater concentration than the water
thereabove.
This process removes the
saline materials from saline water for the purpose of making
the water potable and useful for agriculture without ill
effect.
The novelty of this
invention is that it requires no application of energy from
any source external to the process; that it incorporates no
critical or strategic materials and that it is completely
self-contained.
Existing desalination
processes require the application of heat energy or
electrical energy from an independent source to make the
process operational, whether for direct separation of saline
material from water by electrolytic means using applied
electricity, distillation of steam or evaporated water,
operation of pumps and other equipment necessary to such
processes.
This invention produces
its own electrical energy as well as making it possible to
recover more than 80% of the volume of saline water injected
into the process, as desalinated water.
Minerals such as aluminum
and alloys of aluminum and other minerals react with saline
materials that are dissolved and suspended in saline water.
These chemical reactions cause the saline materials to
combine with the minerals placed in the water for that
purpose. The chemical reactions cause a change in the energy
levels of various atoms in the reacting molecules.
When non-reacting minerals
such as copper, alloys of copper or other minerals are
placed at a distance from the reacting minerals with an
unobstructed quantity of saline water between the reacting
and non-reacting materials, an electrostatic field is caused
to exist.
The mineral in contact wit
the saline water and reacting with the saline water is
called the cathode. The mineral in contact with the saline
water and considered non-reacting is termed the anode. When
the cathode and anode are placed at a distance from each
other with an unobstructed quantity of saline water in
contact with the surface of each, and when an electrically
conductive material is placed so that it continually is in
contact with both the cathode and anode, but not in contact
with the saline water, an electric current is caused to
exist. The rate of chemical reaction, production of
electrical energy and rate of separation of the saline
materials and their removal from the saline water are
proportional.
Saline water tested by
this process was obtained from the Pacific Ocean having a
content of dissolved and suspended solids 44,000 milligrams
per liter of water of which 6400 milligrams of the same
solids were CaCO3 (calcium carbonate). After processing per
this process, wherein the reaction was controlled to
accomplish a separation of saline materials of approximately
70% of the amount contained in the saline water, analysis of
the processed water showed that the total of solid materials
remaining dissolved and suspended in the water measured
10,660 milligrams solids per liter of water. Of these solids
1,530 milligrams were calcium carbonate. The control was
subsequently adjusted to cause more separation and removal
of saline materials; the resulting analyses showing the
processed water to contain 650 milligrams per liter of water
of solid matter, of which 320 milligrams were calcium
carbonate.
The reacted materials do
not adhere to the cathode but disengage as their density
increases and fall to the bottom of the vessel in which they
are contained. Non-reacting materials suspended in the water
being processed become charged in the electrical field
between the cathode and anode. Each particle will then be
attracted to the next as their respective negative and
positive poles come into opposition. Ultimately the
accumulated density exceeds their former buoyancy as a
result of the coalescence by attraction and these materials
deposit at the bottom of the vessel in which they are
contained.
The electric current
produced as a by-product of the desalination process
chemical reaction was measured to have an average value of
0.000022 ampere per square inch of cathode surface in
contact with the saline water being processed. For each
combination of cathode and anode the electromotive force as
measured to be 0.5 volt. The rate of separation and removal
of saline materials from the water, termed desalination, has
been calculated. The calculations are based on the amount of
material separated and removed from the water, the observed
change in measurement of electric current and the amount of
water processed. The rate of desalination of one cubic inch
of saline water in contact with the surfaces of one cathode
and one anode of one square inch area, where the cathode and
anode are in mutual contact with an electrically conductive
material not in contact with the water, is two minutes for
water having a content of 650 parts of solid material
in suspension and solution per million parts of water after
processing from an original state wherein 44,000 parts of
solid material in suspension and solution per million parts
of water were measured before processing.
By analysis 31,675 parts
of cathode materials were reacted and removed from the
cathode for each million parts of water processed, where the
processed water contained 650 parts of solid material in
suspension and solution for each million parts of water.
The material separated and
removed from the water by the desalination process described
herein, are removed from the bottom of the vessels in which
they are deposited, and made available for processing into
chemical, metals, chemical products, metal products, and all
other uses to which they are applicable. Many of the
materials released by the chemical reactions of the process
are released as gases, such as hydrogen, oxygen, chlorine
and others.
These gases partially
combine in the water, small portions of chlorine gas
dissolving. Hydrogen and chlorine combine to form
hydrochloric acid that in turn reacts with calcium carbonate
resulting in free hydrogen gas and precipitant calcium
chloride. The hydrogen gas expands out of the water to
atmosphere.
The chlorine gas is
released when the sodium chloride molecule is disrupted by
the electrochemical reactions of this process. As the
chlorine atoms are recombined as described in the foregoing
so does the sodium atom combine with the carbon atoms of the
disrupted calcium carbonate molecule resulting in
precipitant sodium carbonate and sodium hydroxide.
For a clearer
understanding of the invention, specific examples of the
invention, specific examples of the invention are given
below. These examples are merely illustrative ad not to be
understood as limiting the scope and underlying principles
of the invention.
Example I:
A tubular container of
copper was constructed into which a cylindrical rod of
aluminum was suspended coaxially. The aluminum cathode was
connected to the copper anode with an electrical conductor.
The entire assembly was
oriented with the axes of the cylindrical parts
perpendicular to the earth’s surface. Saline water was
introduced into the anode container. The saline water had a
content of dissolved and solid saline matter of 35,00 parts
per million of water.
The distance by which the
surfaces in the container and the cathode rod were separated
was 0.75 inch. The water was permitted to remain in the
container one hour. After one hour the water was removed and
tested. The remaining dissolved and suspended solid material
was measured at 28,900 parts per million of water.
Example II:
Four tubular copper anode
containers were connected in such a manner as to permit
saline water to be introduced a distance from the bottom of
one tube, then permitted to flow out of the top of that tube
into the next tube where the inlet was in the identical
location of the first, and so on for all four tubes. The
distance from the bottom of the containers to the inlets was
sufficient not to impede the deposition of the precipitant
nor cause the incoming water to be mixed with the
precipitants.
Tubular aluminum cathode
elements were then suspended into an anode container. The
cathodes were connected together by an electrically
conductive material. The anodes were connected together by
an electrically conductive material. The anodes were then
connected to one side of a meter calibrated to be read in
millamperes. The cathodes were connected to an electrical
resistance of 10 ohms. The electrical resistance was
connected to the other side of the ammeter.
The axes of the anode
containers and the cathodes were coaxial and oriented to be
perpendicular with the earth’s surface. The total capacity
of the system was measured at 2.7 gallons of water. At the
bottom of each container a means was provided for the
removal of precipitants.
Saline water was
introduced and permitted to flow continually through the
system at a rate of 2.7 gallons per day. This produced 0.05
amperes of electrical current at an electromotive force of
0.5 volts continually. The water was tested. The total
dissolved and suspended solid saline materials were 36,300
parts of water before introduction into the process and 370
parts per million parts of water after ejection from the
process. The cathode reduction rate was calculated at 0.0013
ounces avoirdupois of aluminum lost for each 100 gallons of
water desalinated. The precipitants were removed as a dense
brine that measured 104,000 parts per million parts of water
of suspended solids for each 2.7 gallons processed.
The present invention in
its broader aspects is not limited to the specific minerals,
mechanizations and examples described, but also includes
within the scope of the accompanying claims any departures
made from such minerals, mechanizations and examples which
do not sacrifice their chief advantages.
What is claimed is:
1. The process of
desalination of salt water which comprises flowing such
water between spaced-apart, substantially vertically
arranged dissimilar metal electrodes in a cell-like means,
the electrodes being connected by an electrical conductor
outwardly of the water, whereby an electric current flows
between them, attracting, by such flow of current, portions
of the salts to each electrode, whereby to cause an increase
in density of water adjacent to each electrode, permitting
settlement downward from adjacent the electrodes to the
bottom of cell-like means, and removing from the bottom a
brine of greater concentration than that of the water
thereabove.
2. The process as defined
in claim 1 together with the subsequent steps of flowing the
upper portions of such water between electrodes of further
cell-like means, and repeating the remainder of the steps so
set forth, whereby to effect progressive desalination
References:
566,324
(8/1896) Kendrick (Cl. 204-150)
2,451, 067
(10/1948) Butler (Cl. 204-248)
3,342,712
(9/1967) O’Keef (Cl. 204-148)
INSTRUCTIONS FOR
CONSTRUCTING A ONE HUNDRED GALLON PER DAY,
OR A ONE GALLON PER DAY
SEA WATER DESALTING UNIT EMPLOYING THE
ELECTROGRAVITATIONAL DESALINATION OF SALINE WATER PROCESS,
U. S. PATENT No.
3,474,014
FOREWORD:
Electrogravitational
Desalination of Saline Water (EGD), is a process designed for
the desalting of sea water to produce potable and agricultural
water as a supplement to existing water supplies, for
application in sea coast communities.
The invention operates much
the same as a storage battery except that there are a great
number of cells, and the electrolyte (sea water), continuously
flows through the system. The amount of residual salts left in
the product water is controlled by the flow rate; the faster
the water flows the more is left in it, conversely the slower
the water flows the more is removed, however, for each design
there is an optimum flow rate and a minimum flow rate. The
average minimum flow rate should never fall below one gallon
per day for any system, but for larger systems this figure is
even too low. The rule of never permitting the system flow
rate to be less than 10% of the designed optimum flow rate in
units over 10 gallons per day is best to follow.
Although some ion exchange
takes place in the system and is the source of the by-product
electrical power that is generated, most of the saline matter
is removed by the electrogravitational phenomenon. Between the
rods (the cathodes) and the tubes (the anodes), an electrical
field comes into existence when tube and rod are connected
together electrically (outside of the electrolyte), with some
kind of resistance load (light bulbs, or motors, etc.)
between. The electrolyte forms the other “connection” between
the rod and tube. The dissolved salts are, in fact, ions
(atomic sized particles) with positive or negative charges,
attached to the water molecules. The electrical field in the
EGO process causes these ions to be detached from the water
molecules and migrate to either the anode or cathode,
depending on the charge of the ion.
The ions accumulate at the
surfaces of each (rod and tube), but only the Oxygen and
Hydrogen ions will react with the materials of which the rods
and tubes are made, and in the case of the designs contained
in these instructions, only the rods are consumed over a long
period of time. The rest of the ions (the salt ions)
accumulate at the rod and tube surfaces, gradually being drawn
downward by gravity until these reach the space below the rod
(where there is no electrical field), where these redissolve
(the ions become reattached to the water molecules), forming a
dense brine. To this brine is added the hydroxides formed by
the ion exchanges (reactions) between rods and those ions we
mentioned before. These hydroxides are in the form of flakes
and whitish in color. These flakes are only slightly more
dense than the water, and though most will fall to the bottom,
some will stay suspended in the water and usually filtered out
before the product water is used. These hydroxides are
harmless, being in fact one of the two constituent materials
used in treating digestive tract ailments in products bearing
trade names of Maalox, Di-Gel, etc. The main ingredients of
these products are aluminum and magnesium hydroxides, of which
ours is aluminum hydroxide.
Other beneficial side
effects of EGD operation include the release of chlorine ions,
which expand out of the water as a gas (rising to and out of
the water's upper surface), some, of course, is carried down
with the other materials. The gaseous chlorine destroys
harmful organisms. All but trace amounts of chlorine are
usually removed from the product water by aerating before
storage, as it comes from the output filter.
DESIGN BACKGROUND:
These instructions contain
basic information for the construction of two different units;
a unit that will produce 100 gallons per 24 hour day of water
containing 400 parts per million total dissolved solids, from
saline ocean water containing 30,000 parts per million total
dissolved solids from which suspended matter has been removed
by filtration to ten microns, and a one gallon per 24 hour day
unit producing water of the same quality as that specified for
the 100 gallon per day unit from the same source .
The designs have been
developed to permit the builder to obtain materials that are
commercially available from hardware stores, plumbing supply
centers, lumber supply centers and retail metal products
suppliers. Significant latitude has been allowed to facilitate
substitutions as well as permitting the builder to fully
decide on certain materials as well as size of materials and
parts. Where strict limitation was necessary in material
selection, and dimensions they are clearly identified. The
designs have been developed from fully tested and demonstrated
laboratory devices.
Construction of tube
assemblies for both types of units only differs in size. Rod
assemblies for the two differ in construction due to the very
small diameter of the one gpd unit's rods. The one gallon unit
is intended to be an emergency device only, the design does
not lend itself well to prolonged use as it is a hand filled
unit, and when not in use must be disassembled completely, and
all parts thoroughly dried (after removing all traces of
saline water by rinsing in fresh water). The following
instructions give more on the subject of storage .
CONSTRUCTION
INSTRUCTIONS:
100 gpd:
Figure I
illustrates a vertical side view with partial cut-away to show
cell (tube and rod, assembled), position and identify certain
components as well as construction fundamentals. The solenoid
shown is for lifting the perforated plate that pushes the
valves open momentarily to dump the waste brine. The dumping
need only be done once each day, and for no more than a half
second of time. A hydraulic cylinder may be used instead, but
this requires a motorized pump. The cylinder may be preferable
over the solenoid in order to get the force needed to raise
the valves against nearly 800 lbs. of water weight, but this
is a decision the builder must make based on equipment
availability. The schedule for Figure I is on the page
following.
Figure II
gives the recommended construction dimensions for the housing.
Items 9 and 14 on Figure I need not be mounted to their
support angles, but can be laid on them. The lid should be
locked into position only to prevent shifting and dislocation
that would adversely affect rod/tube alignment and electrical
connections. The method of locking is optional. Inlet and
outlet pipes are not shown or specified on the housing. The
builder has the option as to which way these should project
from the unit (whether out the ends or the sides), keeping in
mind that the inlet of water to the tubes is at the bottom and
the outlet at the top.
Figure
IIA shows the location of two sets of holes that
correspond to the mounting positions of the rods, and the tabs
for making the electrical connections to the tubes. The .201"
diam. holes are for mounting of the rods to the lids as well
as making the electrical connections to the rods. The .250"
diam. holes are for passing the wires from the tube electrical
connection tabs out onto the lid top where the connections can
be made. The frame for the valve plate lift ropes and lifting
mechanism support is also shown on Figure IIA . Standard
fiberglass sheets come in a maximum size of 4' x 8'. These can
be cemented together with a wide strip of the same material to
obtain the larger dimensions recommended in these
instructions, using epoxy cement (2 part is recommended).
Figure
III and its associated schedule illustrate the
assembly of the tubes for the system. The recommended spacing
center to center of each tube in both directions is 2-1/2"
(from centerline of a tube to the centerline of its neighbor
tubes). The inlet and outlet direction is shown for
illustration purposes only, and as stated are optional.
Figure IV
and its associated schedule illustrate tube constructions. All
the materials recommended are those in use for transfer of
potable water (drinking and cooking water). It is recommended
that the builder use only those materials, and not materials
that might be contaminating.
Figure V
illustrates rods for both 100 gpd and one gpd units. Details VI - X should be
carefully examined. Detail VI and Detail VIII
should be drilled in line with the .201" diam. holes in Figure IIA, which in turn must align
with the tube array.
Detail
VIII supports the tube array and is drilled to
permit the valve stems to hang down. Detail
VI maintains tube alignment and separation at the
top of the tubes, while allowing the tabs to clear.
Detail
IX calls out perforated plastic sheet, but
expanded metal sheet that has been completely coated with a
well bonded coating without obstructing the perforations so
that the waste water may pass through, may be preferred. The
plate must lift the valve stems against approximately 800 lbs.
of water weight, without permanently deforming.
Figure
XI illustrates the electrical connections
recommended; 1) connections are series connections that add
the voltage of each cell so connected to the next, and 2)
connections are parallel connections that add the current
values of the cells so connected. Per the recommended
connections shown, an average total of 997 Watts will be
available. This power is ample for operating a water pump
motor 1/4 hp to 1/3 hp), for filling the unit, at a constant
rate. If it is preferred by the builder that the power be
first converted from the DC produced to AC, it must be kept in
mind that some power loss will result in such conversion. It
is recommended that the builder employ a power panel
containing a wattmeter and switching so that power stability
can be monitored. Power drop-off is directly related to
reduction in desalting activity, and is usually due to the
rods having become coated with hydroxides. This condition can
be corrected without shutting the unit down, by employing a
hand held ultrasonic generator, and touching each tube for a
few minutes to "shake-off" the hydroxide materials. Care must
be taken not to cause an electrical short or to be subjected
to electrical shock during this process. It is recommended
that the ultrasonic device be fully electrically insulated.
The rods can be vibrated through their mounting screws.
One gpd:
Figure
XII illustrates the recommended container for a
one gallon emergency use device. Figure XII and its associated
schedule are considered clear enough to permit construction of
such a device, employing the other applicable parts of this
instruction (Figures IV, V, XI and their associated
schedules), and the general recommendations given herein.
Figure
XII - Item 10 is the top plate of the base box.
This plate supports the rods and is where the electrical
connections should be made. The electrical leads can be
connected to a "jack" type socket on the side of the housing
(base box), from which a number of items can be operated if
fitted with mating plugs. Some of the possible devices are: an
emergency transceiver radio, light, emergency radio
transmitter beeper. The device will produce an average 0.98
Watts, ample in a number of the devices mentioned. As shown on
Figure XII, the lid assembly is also the filling reservoir.
Again, as in the 100 gpd unit, the builder has the option of
the outlet location, as well as the inlet to the first cell.
The outlet should have a valve so that the flow can be
controlled, but when flow is controlled at the outlet, extra
care must be taken to prevent overflow of the tubes from
filling with more water than is being allowed to pass out.
Corrosion and electrical shorts can result that would
seriously effect the desalting capability of the device.
GENERAL INFORMATION:
If a unit is stopped for any
reason, it must be drained of all saline water, the electrical
circuit opened (switched off), the cell components thoroughly
rinsed and dried (fresh water rinse). If the units are to be
stored after having been used, stopped and dried, the rods
should be removed from the cells and stored separately. Some
corrosion of the tubes may occur in storage, or a patina may
form in them. Providing that such storage is not for an
exceptionally long period that might seriously damage the
tubes, the unit can usually be put back into operation very
quickly by filling the tubes with any of the liquid copper
cleaners generally available to remove the corrosion products
.The cleaner must be thoroughly rinsed out of the system
before using the system again. The rods should be cleaned to
remove all oxides and expose bare metal. Electrical connection
points should be carefully inspected and corroded parts
cleaned or replaced .
The desalting unit should be
filled with filtered sea water taken from far enough offshore
to minimize the pollutant content. The finer the filtration,
the lower the risk of potential troubles. Petroleum
contaminants for instance, can cause very frustrating
contamination that will obviously stop the process from
operating effectively.
These units should be
operated in as motion free an environment as possible.
Agitation of the water in the tubes will cause mixing which
totally defeats the process function. Too high a flow rate
will cause turbulence that results in the same problem. The
one gallon unit can be used in life boats as long as there is
relative calm, or as long as internal "sloshing" can be
prevented.
The waste brine tank in the
bottom of both units must be fitted with a means for removing
the brine periodically. To monitor the level, a clear plastic
window can be cemented into the housing wall, and a manually
operated drain valve installed. The brine can be evaporation
dried and its salt content recovered .
SCHEDULE FOR FIGURE I
[ # Required / gpd]
1)
108"
x 78" fiberglass sheet (3/16" to ½" thick)
[1 / 100 ]
2)
Figure
IV tube assembly [ 660 / 100 ]
Figure
IV tube assembly [ 48 / 1]
3)
Figure
V rod [ 660 / 100 ]
Figure
V rod [ 48 / 1 ]
4)
#8-32
x 1" round hd. machine screws [ 660 /
100 ]
#5-40
non-conductive, non-corrosive hex. nuts [ 192 / 1
]
5)
Detail
IX (can use fully epoxy coated expanded metal) [ 1
/ 100 ]
6)
1/4""std.
thd. eye bolts w/nuts [ 4 / 100
]
7)
1/4"
marine quality nylon rope [ approx.600 ft. /
100 ]
"
" " " " [ 15 ft. / 1 ]
8)
DC
(or optional AC) 1" stroke vert.mnt. solenoid. [ 1 / 100
]
(must
lift min. 1000 lbs .)
9)
Detail
VI fiberglass sheet (3/16" to 3/16" min. thick) [
1 / 100 ]
10)
3"
x 6" x 1/4" aluminum angle (paint with epoxy) [ 48
ft. / 100 ]
11)
2"
x 2" x 1/4" aluminum angle (paint with
epoxy) [ 144 ft. / 100 ]
12)
3"
x 3" x 1/4" aluminum angle (paint with epoxy) [ 28
ft. / 100 ]
13)
104"
x 84" fiberglass sheet (3/16" min. Thick) [
2 / 100 ]
84"
x 74" " " " "
" [ 2 / 100 ]
14)
Detail
VIII fiberglass sheet (3/16" to 1/2" thick)
[ 1 / 100 ]
15)
Detail
VII 1/2" P\/C or ABS pipe, and elbows (cementable) [ as
req. / 100 ]
16)
72"
x 102" fiberglass sheet (min.3/8" thick, double-up 3/16"
cementing
pieces together at edges to prevent leaks) [ 1 / 100 ]
17)
3"
x 6" x 1/4", aluminum angle (paint with epoxy) [
13 ft. / 100 ]
18)
1/4"
- 20 x 4" bolt with min. g' thread length [
4 / 100 ]
19)
1/4"
- 20 hex. nut for above bolts, with lock washers [ 4 /
100 ]
20)
2"
spacers (cut from tubing, or drill cut round -Alum.) [ 4
/ 100 ]
21)
1/4" aluminum plate 6" x 32" [ 1 / 100
]
22)
Detail
X; 1/4" -20 x 36" threaded round [ 2 / 100 ]
23)
Detail
X; 1/4" -20 hex. nuts & lockwashers [ 4
/ 100 ]
24)
Detail
X; 1/2" O.D. (min. 3/8" I.D.) tubing, 30-1/2" lg. [ 2 /
100 ]
SCHEDULE FOR FIGURE III
For 100 gpd unit:
A ~ 30 rows of cells
interconnected as shown
B ~ 23 cells per row, with
transition connections made per Detail VII
C ~ Salt water inlet into
bottom of first cell
D ~ Desalted water outlet
from top of last cell
E ~ Cell inlet
F ~ Cell outlet
NOTE: Connect first cell and
next cell outlets to adjacent cell inlets for 659 cells (last
cell's outlet is outlet D).
For 1 gpd Unit:
A ~ 8 rows of cells
interconnected as shown
B ~ 6 cells per row, with
transition connections per Detail VII
C )
D ) Same as above (100 gpd
schedule)
E )
NOTE: connect first cell and
next cell outlets to adjacent cell inlets for 48 cells (last
cell's outlet is outlet D).
SCHEDULE FOR FIGURE IV
1) Plastic pipe "T"
(PVC orABS), cementable, modify for achieving dimension-A, if
necessary:
for
100 gpd -- 1" x
1/2"
1320
required
for
1 gpd = 3/4" x
1/"
96
req.
2) Plastic pipe:
for 100 gpd = 1/2" dia.
(PVC/ABS)
360
ft. req.
for
1 gpd = 1/4"dia.
(PVC/ABS)
40
ft. req.
3) Plastic pipe' el'
(PVC/ABS), cementable, modify for achieving dimension -A, if
necessary:
for
100 gpd =
1/2"
1320
req.
for
1 gpd =
1/4"
96
req.
4) Copper tubing:
for
100 gpd = 1" diam x 0.03 wall x 64" lg.(3520
ft.) 660 req.
for
1 gpd -- 3/4" dia. x .06 wall x 18" lg. (72
ft)
48
req.
5) Plastic pipe:
for
100 gpd -- 1" dia. (PVC/ABS) x 2" lg. (110
ft.)
660 req.
for
1 gpd = 3/4" dia. (PVC/ABS) x2" lg. *
ft.)
48
req.
6) Plastic (PVC/ABS) closure
caps drill thu to fit 7:
for
100 gpd -- 1"
cementable
660
req.
for
1 gpd --- 3/4"
cementable
48
req.
7) Standard
faucet washer:
for
100 gpd
--
660
req.
for
1 gpd
--
48
req.
Note:
Must seat and seal hole in 6 without binding, but leak free
7) 2" long bolt selected to
fit hole in faucet washer:
for
100 gpd
--
660
req.
for
1 gpd
---
48
req.
8) 2" long bolt selected to
fit hole in washer:
100
gpd
--
660
req.
1
gpd
--
48
req.
9) Hex nuts to fit bolt 8:
100
gpd
--
1320
req.
1
gpd
--
48
req.
10) #6 self-tapping
screw, 3/8" long:
100
gpd
--
660
req.
1
gpd
--
48
req.
11) 3/16" wide x 1"
lg. X .03 max thick, screw mounting electrical wiring link:
100
gpd
--
660
req.
1
gpd
--
48
req.
Dimension A: for 100
gpd = 2-1/2" ; for 1 gpd = 2"
Dimension B: for 100
gpd = 1-1/2" max.; for 1 gpd = 1-1/2" max.
Dimension C: for 100 gpd =
2"; for 1 gpd = 2"
Dimension D: for 100
gpd = 3/4"; for 1 gpd = 3/4"
Dimension E: for 100
gpd = 1/2" dia.; for 1 gpd = 1/4" dia.
SCHEDULE FOR FIGURE XII:
1) 3" x 3" aluminum angle x
¼" thick (epoxy paint), 22 ft. req.; make frame so that
fiberglass sheet attach inside
2) Lid: top & bottom of
lid must be assembled and sealed to lid frame as a box, and so
assembled that the fill pipe just enters the gap between the
rod and the tube without binding or causing spillage. Lid
"box" is salt water reservoir for and filling thru 6" diam.
hole.
3) Bottom support plate,
1/8" min. fiberglass sheet, 1 req.
4) Fiberglass sheet for
sides, bottom and lid: approx. 25 sq. fr., 1/8" min. thickness
5) 1" x 1" x 1/8" aluminum
angle, 30 ft. required: when preparing assembly with items 3
& 9 & 10, arrange so that disassembly can be achieved
with ease (screw mount support ledges only. Short pieces on
which these plates can be laid then screwed in place.).
6) Seal this 19" x 15" x
1/8" thick min. fiberglass sheet to box as reservoir for waste
brine. A drain pipe must be added, with a valve out of box
side, to permit waste brine removal.
7) [Missing in plans]
8) Epoxy coated expanded
metal sheet for valve lift, 1 req.
9) Tube holding plate, 1
req, 1/8" fiberglass sheet.
10) Rod holding plate, 1
req., 1/8" fiberglass sheet.
Figure I: Elevation, 100
gpd assembly ~
Figure II: Elevations,
100 gpd unit housing ~
Figure IIA: Top View, 100
gpd housing ~
Figure III: Tube array
plan & tube connection data ~
Figure IV: Tube assembly
construction ~
Figure V: Rod assemblies
construction ~
Details VI: Figure X:
Figure XI: Electrical
Connections ~
Figure XII: Housing for 1
gpd unit ~
