U.S. patent application number 12/790361 was filed with the patent office on 2011-03-03 for axial-sump electrolytic flow cell.
Invention is credited to Karl J. Fritze, Rudolph R. Hegel, Brian Luebke.
Application Number | 20110048964 12/790361 |
Document ID | / |
Family ID | 43623243 |
Filed Date | 2011-03-03 |
United States Patent
Application |
20110048964 |
Kind Code |
A1 |
Luebke; Brian ; et
al. |
March 3, 2011 |
AXIAL-SUMP ELECTROLYTIC FLOW CELL
Abstract
Apparatus and associated methods pertaining to an axial-flow
electrolytic sump for operation in low to medium conductivity hard
water. The axial-flow electrolytic sump can include easily
replaceable components providing for ease of maintenance, low-cost
replacement, and the lowest impact to the environment for the
service life of the system. In general, the axial-flow electrolytic
sump can comprise a removable/replaceable electrode cartridge that
is operably enclosed in a sump housing.
Inventors: |
Luebke; Brian; (Trempealeau,
WI) ; Fritze; Karl J.; (Hastings, MN) ; Hegel;
Rudolph R.; (Richfield, MN) |
Family ID: |
43623243 |
Appl. No.: |
12/790361 |
Filed: |
May 28, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61181980 |
May 28, 2009 |
|
|
|
Current U.S.
Class: |
205/687 ;
204/242; 204/275.1 |
Current CPC
Class: |
C02F 1/46104 20130101;
C02F 1/4691 20130101; C02F 2001/46152 20130101; C02F 2201/46115
20130101; C02F 2201/4611 20130101; C02F 2201/003 20130101; C02F
2001/46133 20130101 |
Class at
Publication: |
205/687 ;
204/275.1; 204/242 |
International
Class: |
C25B 9/00 20060101
C25B009/00 |
Claims
1. An axial-flow electrolytic cell, comprising: a sump assembly
having a sump head and a sump chamber, the sump head including a
cartridge aperture providing access to an internal volume of the
sump chamber; and a removable electrode cartridge having an
electrode assembly mounted to a cartridge head, the cartridge head
adapted for removable attachment to the sump head such that the
electrode assembly is positioned within the internal volume of the
sump chamber.
2. The axial-flow electrolytic cell of claim 1, further comprising:
a plug assembly attaching to a plug receptacle on the cartridge
head, the plug assembly providing power to the electrode assembly
when the plug assembly is connected to the plug receptacle.
3. The axial-flow electrolytic cell of claim 2, wherein the plug
assembly is axially aligned with the electrode assembly when the
plug assembly is connected to the plug receptacle.
4. The axial-flow electrolytic cell of claim 1, wherein the sump
head includes a flow inlet port and a flow outlet port, the flow
inlet port and the flow outlet port being axially aligned so as to
define a sump mounting width between the flow inlet port and the
flow outlet port.
5. The axial-flow electrolytic cell of claim 4, wherein the sump
mounting width is less than an electrode length.
6. The axial-flow electrolytic cell of claim 4, wherein the sump
head includes a quick connect feature at the flow inlet port and
the flow outlet port.
7. The axial-flow electrolytic cell of claim 1, wherein the sump
chamber is removably connected to the sump head with a rotational
connection means.
8. The axial-flow electrolytic cell of claim 7, wherein the
rotational connection means comprises a threaded connection.
9. The axial-flow electrolytic cell of claim 1, wherein the
removable electrode cartridge is rotatably connected to the sump
head.
10. The axial-flow electrolytic cell of claim 9, wherein the
removable electrode cartridge includes at least one bayonet tab
that interfaces with a retention flange on the sump head so as to
positively retain the electrode assembly within the internal volume
of the sump chamber during operation.
11. The axial-flow electrolytic cell of claim 1, wherein the
removable electrode cartridge further comprises a sleeve positioned
over the electrode assembly, the sheath comprising a scale
inhibiting material.
12. The axial-flow electrolytic cell of claim 11, wherein the scale
inhibiting material comprises polyethylene.
13. The axial flow-electrolytic cell of claim 11, wherein the sump
head, sump chamber and cartridge head are constructed of a
non-conducting material, the non-conducting material being
different than the scale inhibiting material.
14. The axial-flow electrolytic cell of claim 13, wherein the
non-conducting material is selected from the group consisting of:
ABS, PVC, and PPO.
15. The axial-flow electrolytic cell of claim 1, wherein a second
sump housing having a second sump internal volume can be attached
to the sump head; and wherein a second removable cartridge assembly
having a second electrode assembly can be attached to the sump
head, wherein the second sump internal volume and second electrode
assembly are matched so as to vary electrolytic performance as
compared to the original sump internal volume and electrode
assembly.
16. The axial-flow electrolytic cell of claim 15, wherein the sump
head remains operably mounted within a flow system as the
electrolytic performance is varied through attachment of the second
sump housing and the second electrode assembly.
17. A method of electrolytically treating fluid comprising:
providing a sump head having a fluid flow inlet and a fluid flow
outlet, wherein the fluid flow inlet and fluid flow outlet are in
axial alignment; attaching a sump chamber to the sump head to
define an interior sump volume; mounting a removable electrode
cartridge in a cartridge aperture in the sump head such that an
electrode assembly is positioned within the interior sump volume;
supplying a nontreated fluid flow to the fluid flow inlet; and
removing an electrolytically treated fluid flow from the fluid flow
outlet.
18. The method of claim 17, further comprising the step of:
replacing the removable electrode cartridge with a second electrode
cartridge upon reaching an end of a useful life of the removable
electrode cartridge.
19. The method of claim 17, further comprising the step of:
supplying power to the electrode assembly with a removable plug
assembly, the removable plug assembly attaching to a plug
receptacle in a cartridge head of the removable electrode cartridge
such that the removable plug assembly is in axial alignment with
the electrode assembly.
20. The method of claim 17, further comprising the step of:
covering the electrode assembly with an electrode sleeve, wherein
said electrode sleeve comprises a scale resistant material.
21. A fluid flow system for treating a fluid with electrolysis,
comprising: a removable electrode cartridge having an electrode
assembly mounted to a cartridge head; and a means for mounting the
removable electrode cartridge to a fluid flow system, wherein the
removable electrode cartridge is replaceable with a second
removable electrode cartridge without disassembling the means for
mounting from the fluid flow system.
22. The fluid flow system of claim 21, wherein the means for
mounting comprises a sump head such that the electrode assembly is
positioned directly within a sump chamber attached to the sump
head.
23. The fluid flow system of claim 21, wherein the means for
mounting comprises a cartridge fitting directly mounted within a
conduit such that the electrode assembly is positioned directly
within the conduit.
Description
RELATED APPLICATION
[0001] The present application claims the benefit of U.S.
Provisional Application No. 61/181,980 filed May 28, 2009, and
entitled "AXIAL-SUMP ELECTROLYTIC FLOW CELL", which is incorporated
herein in its entirety by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a device which treats fluid
electrolytically, typically by generating gases and such that can
be dissolved into the fluid. More specifically, the present
invention relates to an electrolytic flow cell device having an
improved design utilizing easily replaceable to components to
promote ease of use and installation as well as reduced costs of
operation.
BACKGROUND OF THE INVENTION
[0003] Electrolytic flow-through cells are used extensively in
treating swimming pool water. In a pool installation, these
electrolytic flow-through cells are utilized to generate chlorine
from a chloride-based salt that is added to the water. When this
salt containing water is passed through the electrolytic
flow-through cell, the electrodes contained therein pass electrical
current through the salt water passing from electrode to electrode.
The resulting current flow generates chlorine, molecular oxygen,
and molecular hydrogen. The electrodes can be made from any
electrically conductive material but are frequently constructed of
titanium due to its high resistance to corrosion. Additionally, the
electrodes are typically coated with metallic oxides such as, for
example, ruthenium, iridium, platinum, rhodium, and palladium that
serve to reduce the oxidation of the titanium electrodes and
augments the generation of gasses, oxidizing and reducing agents
such as, for example, hydrogen peroxide, ozone, atomic oxygen,
atomic hydrogen, hydrogen ions, and hydroxide ions. Absent this
metallic oxide coating, the active surfaces of the titanium
electrodes will oxidize and have a detrimental effect on the active
surfaces until the titanium electrode is ineffective. Additionally,
any uncoated or raw edges provide unwanted nucleation sites which
precipitate scale.
[0004] Electrolytic flow-through cells similar to these pool
devices have been developed to treat water to affect its
potability. Various contaminants including metallic ions such as,
for example, manganese, iron, arsenic, lead, chrome, aluminum,
antimony, radium, and uranium, and other undesirable compounds such
as, for example, hydrogen sulfides can be physically altered by
interacting with electrolyzed fluids such that physical filtration
can thereafter remove the contaminant. The list of known
contaminants that can be successfully treated by this type of
process continues to expand. Water sources which are desired to be
used as sources of potable water have on average, significantly
less dissolved solids, typically ranging from a conductivity of 100
to 1200 microsiemens, as compared to what is normally found in
swimming pools. Also, the type of dissolved solids required for
swimming pool water disinfection must contain chlorides and these
are most often derived from using sodium chloride salt. Thus the
chlorides are converted into chlorine-based disinfectants, while
the sodium metals remain soft. Soft minerals do not destructively
scale electrodes in the manner that hard minerals such as calcium
and magnesium do. Also, chlorine compounds tend to assist in
keeping the electrodes clean. Water sources, such as well water are
mostly full of hard minerals without chlorine and therefore tend to
cause significant scaling issues and can greatly degrade the
long-term performance of these electrolytic flow-through cells.
[0005] While there are have been many different types of geometries
available to arrange electrodes in a cell to treat a flow of
aqueous fluid, the axial-flow variant is most common. Axial flow
electrodes can typically take advantage of cylindrical conduits
particularly when any significant pressure is present.
Unfortunately, there are many disadvantages with a purely axial
design such as, for example, small flow cross-sections, rectangular
flow passageways, small aspect ratios, side electrical contacts,
run-dry concerns, difficulty with electrode replacement, fluid
mixing issues, compactness and materials of construction as
detailed below.
[0006] Any fluid distribution system has conduit, i.e., pipes or
tubing, which is selected for the required flow rate and having an
acceptable pressure loss. For example, residential plumbing systems
are typically 3/4'' to 1'' in pipe size, which has an internal
dimension (d) of 1'' or less. It is difficult to arrange electrodes
inside a similarly sized residential plumbing system without
reducing the net flow area and such arrangements typically require
very long electrodes to gain the necessary surface area to conduct
enough electrical current. These long electrode arrangements are
often problematic in trapping scale and can become less efficient
when large current densities coupled with low fluid flow rates
aerate the electrode with excessive gas bubble formation.
Therefore, electrolytic flow-cells which take advantage of properly
sized electrodes generally reside in conduits having a
significantly larger cross-sections.
[0007] The most practical method of manufacturing electrodes is in
flat sheets of titanium. These sheets are then coated with iridium,
ruthenium, platinum, rhodium, and/or palladium. After these metals
are thermally bonded to the titanium, the flat sheets are then
blanked into flat electrode shapes. The cell arrangement of flat
blades which provides the best use of surface area is a parallel
stack of blades with alternating polarities. For example, a
cathode, anode, cathode . . . array of (n) blades of dimension (x)
by (y) provides for a total active surface area of xy (n-1). While
other flat and non-flat blade geometries are possible, the flat
sandwich geometry is practical and is widely used in the industry.
These sandwich type geometries almost always have a parallelogram
cross-section. If the blade thickness is (t) and the interspacing
between the electrodes is (s), then the dimension of the flow cross
section width is x(tn+s(n-1)). The flow area therefore becomes
xs(n-1). Lastly, it is advantageous to have flow area
xs(n-1)>.pi. d.sup.2/4. For example, a square flow cross section
of (9) blades each having a blade thickness (t) of 0.025'' thick
requires an internal conduit size of at least 1.42 times larger
than a 1'' internal diameter pipe to carry the required flow
without any additional pressure drop. However, the chamber internal
diameter should be even larger to accommodate any scale build-up.
This means that a starting design point for an axial flow chamber
must be a 11/2'' pipe to be used with 1'' pipe systems. For this
example, the blades would have a width (x) of 0.886'' with an
internal spacing of 0.098''.
[0008] If the above example is expanded to create a typical
axial-flow cell with a 80 sq. inch surface area, than the (9)
blades would have n-1 or (8) active surface areas. 80/8=10''. Each
blade is required to be 10'' long. The resulting aspect ratio is
0.886/10 or 0.089. This means that the blade is 11.28 times longer
than it is wide or its width is 0.089 times its length. When the
blades have aspect ratio smaller than about 0.25, there can be
difficulty in dislodging scale during polarity reversals and
excessive ventilation due to bubbles forming and keeping the
downstream regions of the blades wet and conducting electrical
current. For this reason, it is preferred to have shorter, wider
blades than narrow longer blades. Creating a square cross section
with a 0.25 aspect ratio is not possible with a small number of
blades. If more blades are added, then the costs of the blades and
connection hardware multiply accordingly. In order to optimize
economics, it is desirable to keep the blade count as small as
possible.
[0009] Given a purely axial-flow electrode design, it is necessary
for the electrical contact to exit 90 degrees from the flow axis.
Such cross connections are not advantageous to economic blade
manufacturing and they necessarily complicate chamber design. Any
side opening in a conduit is a potential cause of structural
concerns and requires gaskets, potting agents, caps, or suitable
secondary conductors. Any time the electrical connection is made
internal to the chamber, the metals must be the very same material
or galvanic corrosion will rapidly degrade the contacts. Also, to
achieve a robust electrical connection, any active coatings on the
electrodes should be removed to get to un-oxidized base metals. For
example, if an electrode is made from titanium with an iridium
oxide coating, then the coating should be removed and a suitable
titanium connector must be joined gas-tight to effect a solid
connection. This is not only expensive in terms of material and
parts but also in assembly labor. This also creates a joint which
is inferior to passing an integral blade tab through the side of
the conduit.
[0010] Operation of axial-flow chambers in a horizontal manner can
subject them to partial-flow conditions when the fluid flow rate is
less than maximum and/or there is entrapped air resulting in the
electrodes being only partially wet. Partial-flow conditions do not
promote efficient operation and can reduce the net effectiveness of
the electrolytic flow-through cell. If axial flow chambers are used
in a vertical pipe run, then the fluid can either be flowing
upward, or downward. In a downward flow condition, the fluid can
simply drop down the pipe and not even fill the chamber allowing it
to run dry. The only effective orientation for an axial-flow
chamber is vertical up-flow. However, such a vertical up-flow
orientation can often require special modifications to the existing
piping scheme and may not be suitable for many applications.
[0011] With respect to electrode replacement, use of an axial flow
design can necessitate the placement of a large access port on the
conduit. Alternatively, the entire axial-flow chamber can be
designed to be removed from the piping/tubing scheme.
[0012] Electrolyzed water is more effective in treating the
contaminants in the fluid if there is some type of mixing that can
transpire as close to the actual electrolysis as possible. When the
mixing occurs in the direct vicinity of the electrodes, mixing
features can result in the formation of flow eddies. These
turbulent non-laminar flow conditions can greatly augment the
formation of scale, particularly on the flow-disturbing feature
itself. Scale which develops on these flow disturbing features will
grow rapidly and soon completely occlude the chamber. Therefore,
traditional axial-flow chambers should have perfectly laminar flow
conditions in the direct regions of the electrodes. If the fluid is
to be mixed, it should therefore be done after the chamber and thus
requires additional system length, complexity, and can result in
unwanted pressure drops.
[0013] It is often desirable to keep any fluid system component
compact to enable it to be easily adapted into the plumbing system
or flow apparatus. Axial-flow chambers are the longest type of
electrode system and require the most space for their
operation.
[0014] With respect to materials of construction, ABS, PVC, and PPO
are commonly used in water treatment devices. These materials are
resistant to the typical concentrations of chemicals found and used
in potable water and are also structurally sound and economic to
use. These materials exhibit a high surface energy to enable
adhesives bonding, particularly where an electrode tab exits the
housing wall. Many structural potting agents can make hermitic
long-term bonds to these plastics. Unfortunately, electrolytic
cells fabricated with these materials tend to enable the
precipitation and adherence of scale. Scale tends to precipitate
when these plastic materials are in close proximity to the
electrical field of the electrodes. Once scale begins to adhere to
the plastic material, the scale continues to rapidly build and
eventually grows to plug the chamber resulting in increased back
pressure and reducing or eliminating fluid flow. Scale in contact
with these plastic materials is not able to be dissolved by the
operation of anodic acid production during electrolysis. Polarity
reversal is only marginally helpful at preventing, controlling, or
removing scale formations remotely located from the surface of the
electrode.
[0015] There are materials which are better at preventing the
adherence or precipitation of scale deposits. There are materials
which discourage the formation of scale such as acrylic,
polycarbonate, polysulfone, and polyethylene. Unfortunately,
acrylic is to brittle for structural integrity during pressure
cycles, polycarbonate has poor chemical resistance to chemicals
used with potable water, and polysulfone is expensive. Polyethylene
has many attractive benefits, low cost, high chemical resistance,
low scale build, very fatigue resistant and it is easy to mold.
Unfortunately, PE has very low surface energy and therefore it is
very difficult to use potting agents such as epoxy and the like to
create a long-term hermitic bond to seal integral electrode
conductors through the housing wall. PE is also a poor material to
use with high-pressure because of excessive elongation, flexing and
creep in moderate to high stress applications.
[0016] As discussed above, current designs of axial-flow style
electrolytic flow-though chambers suffer a variety of problems that
can lead to inefficiency and increased operational costs. As such,
it would be beneficial to have new designs for electrolytic
flow-through chambers that overcome the limitations of current
devices.
SUMMARY OF THE INVENTION
[0017] The present disclosure is directed to an electrolytic cell
for operation in low to medium conductivity hard water that can
keep its electrode scale free for an extended life cycle before
maintenance. In view of the aforementioned issues with the current
design of electrolytic flow-through cells, it is the intent of this
invention to define multiple improvements to the existing designs.
As part of this invention, an improved electrolytic cell will
generally include easily replaceable components providing for ease
of maintenance, low-cost replacement, and the lowest impact to the
environment for the service life of the system. A representative
axial-flow sump design of the present invention provides for a
solution to all of the previously stated shortcomings of existing
axial-flow systems. In general, the axial-flow sump system can
comprise a replaceable electrode cartridge that is housed in a
sump. In one representative embodiment, the replaceable electrode
cartridge comprises a quarter-turn bayonet type electrode cartridge
for replaceable mounting in the sump.
[0018] In a preferred embodiment of an axial-flow sump cell, the
fluid flow path is arranged to allow fluid entry perpendicular to a
main flow axis at a top of the sump and then allowing the fluid to
flow axially downward thereafter to exit inline with the major flow
axis. The major flow axis is defined as a vertical line centered
about the middle of the electrode array. When the fluid flow is
allowed to enter on the side of the electrode array, the problems
of inlet flow area cross-section are avoided and can be made much
larger without impacting the diameter of any conduit diameter. The
inlet cross-section is no longer defined by the limitations of
traditional axial-flow cell geometry, but can take advantage of
additional flow area on the side of the electrodes. The exit flow
can be in-line with the major flow axis, perpendicular to it, or
vented out both sides as desired thereby increasing flow
cross-section as desired.
[0019] In an embodiment of the axial-flow sump cell, the electrodes
are arranged in a traditional alternating parallel array and as
such result in a rectangular flow cross section on a plane
perpendicular to the major flow axis. When an electrode pack is
immersed into a sump, the issues of creating a rectangular flow
passageway which is suitable as a hydraulic super structure are no
longer necessary as the sump provides ample volume to house the
rectangular flow passageways without impacting the housing
geometry. Also, the sump and head can be optimized for hydraulic
structural integrity. The uses of a round sump and head are
divorced from and have no impact on the shape of the removable
electrode cartridge.
[0020] In a representative embodiment, a sump and head can be made
of sufficient size to allow for large electrode widths and short
lengths independent from the normal constraints of traditional
axial-flow cell design. The aspect ratio of the present axial-flow
sump electrode can be better than 0.25. Also, sump length can be
increased to allow a variety of different electrode cartridges,
each having differing amounts of surface area, blade spacing, and
coatings as desired for various functions. In one presently
contemplated embodiment, an electrode can be 5.25'' long by 1.50''
wide to provide an aspect ratio of 0.29 (1.50/5.25=0.29). This
means that the electrode is only 3.5 times as long as it is wide
which shortens the length that scale needs to be scavenged and
limits the size of the resulting bubble formations as they coalesce
and grow along the blade. Smaller bubbles dissolve into the fluid
faster and more efficiently then larger ones. Also, a shorter
electrode tends to get less ventilated at low fluid flow rates and
can thereby remain wetted and operational during electrolysis.
[0021] In another embodiment, the axial-flow sump of the present
invention allows for electrodes to be fabricated with integral
conductor tabs extend outward in line with a major flow axis. Such
an orientation allows the electrodes to be easily fashioned into a
removable cartridge having a round sealing means such as, for
example, a gasket or o-ring style seal. This round sealing means
enables rotary motion to be utilized in facilitating installation
and removal of an electrode cartridge. In some embodiments, the
electrode cartridge can comprise at least one bayonet tab that
serves to engage the cartridge with a sump to provide a secure
connection during operation and to facilitate removal via rotation
of the electrode cartridge with respect to the sump. The electrode
cartridge can also rotatably connect to the sump using other
attachment means such as, for example, threads, or through suitable
axial attachment means including quick-connect style
connections.
[0022] Another aspect of the axial-flow sump of the present
invention is that sump geometry insures immersion of electrode
packs in a volume of fluid at all times. The nature of the sump is
such that gravity always keeps the sump filled with fluid so that
there is no condition in which the electrodes will be in operation
without fluid being present. In the event that the fluid flow rate
is very low, the fluid in the inlet and exit conduits can be in a
partial flow condition. Even in this partial flow condition, the
design of the sump still provides sufficient fluid volume to keep
the majority of the electrode immersed and therefore operable.
[0023] In another aspect of the present disclosure, an axial-flow
sump features a removable electrode pack or electrode cartridge.
Electrodes can be easily disconnected from an electrical connection
via a plug if desired, or alternatively, wires can be potted into
the electrode cartridge as desired. In one embodiment, a power plug
is attached to the electrode cartridge as it can reduce
manufacturing and consequently, replacement cost of the replaceable
electrode cartridge. Further, the removable electrode cartridge can
be divorced from any additional electrical control or monitoring
instrumentation such as temperature, pressure, and flow transducers
that can be integral to a sump or within a flow system. By
separating the removable electrode cartridge from any control or
monitoring function, there exists no requirement for circuitry such
as printed circuit boards, lights, or similar elements to be
integrated into the removable electrode cartridge. As such, the
design of the removable electrode cartridge can be optimized for
the electrodes and without sacrificing electrode performance so as
to accommodate system control or monitoring. In general, the
replacement cost of this removable electrode cartridge is reduced
as there is little additional material than the electrode blades
themselves. As the electrodes are the elements that require the
most maintenance due to their tendency to foul with mineral scale,
the removable cartridge can be easily removed and placed into a
suitable cleaning fluid such as muriatic acid without worry that
something will be damaged. In the event that the precious metal
coating on the electrode has worn off due to long-term use,
replacement of the removable electrode cartridge is fast and easy
and can be done without specialized tools or the need for service
technicians. In addition, a removable cartridge can be small in
size so as to generate minimal material waste for environmentally
conscious recycling.
[0024] In another aspect of the present disclosure, axial flow-sump
geometry as disclosed provides the advantage of mixing evolved gas
bubbles into a fluid stream to promote oxidation/reduction of
contaminants contained in the fluid stream. A treated fluid stream
exits the bottom of the electrodes and then is forced to take a 180
degree directional change in a large flow cross-section so as to
limit any resulting back pressure. The treated fluids can remain in
contact for additional time as they mix within the sump and
precipitate contaminants before being collected into the exit port
for subsequent filtration. The nature of a vertically descending
fluid flow and open bottom electrode array is that gravity can
assist any precipitated solids to drop clear of the electrodes and
fall to the bottom of the sump. When the flow rate is elevated,
these solids can be fluidized and swept out of the sump to be
captured in the filter.
[0025] In another aspect of the present disclosure, an axial-flow
sump architecture takes advantage of a vertical electrode that can
be housed in sump of any length with horizontal inlet and outlet
connections. A resulting horizontal run between the inlet and
outlet connection is kept substantially short to allow for easy
connection with a horizontal conduit scheme. The axial-flow sump
architecture is both easy to connect to an existing piping system
and correspondingly difficult to install in an incorrect or
unadvantageous orientation unlike traditional axial-flow systems.
While the axial-flow sump architecture tends to emphasize fluid
flow in a single direction, the fluid flow can also be reversed if
desired without impacting performance of the axial-flow sump.
[0026] In another aspect of the present disclosure, it can be
advantageous to use polyethylene in close proximity to the
electrodes due to the polyethylene's resistance to scale formation.
However, as the polyethylene is not a good choice for a hermetic
blade conductor seal or a structural housing, polyethylene can be
used as a sleeve or shroud to surround the electrodes. While using
polyethylene as a sleeve or shroud around the electrodes, a main
structural element of electrode cartridge can be made from a
non-conductive material such as ABS, PVC, and PPO to meet
structural requirements. Electrode conductors can be passed through
appropriate molded or otherwise formed apertures and potted with
traditional agents such as, for example, urethane, epoxy, or
acrylic. The electrodes can be surrounded by a thin shroud of
polyethylene or material exhibiting similar properties including
resistance to scale formation while remaining free from the
structural strength and hermetic sealing requirements of the main
structural element of the electrode cartridge. Anywhere there is an
electrical field or ionic activity on or near the electrodes,
materials necessary for supporting the electrodes and controlling
the flow path therefrom can be made from polyethylene to reduce
scale buildup. When the electrodes are surrounded by a sleeve or
shroud, it is generally desirable to provide for a sleeve or shroud
shape that forces all of the fluid to be treated into a region
between an anode and cathode. Any fluid forced to pass between a
cathode and anode will have the best possible interaction with
high-energy oxidation and reduction activity proximate to active
electrode surfaces
[0027] In another aspect of the present disclosure, an electrode
can be fabricated such that any region of the electrode which is
not active such as, for example, the edges can be covered by a
material which shields the inactive edge from a fluid stream or
alternatively, the edges can be activated by coating them with
precious metals that prevent the base titanium from becoming
oxidized and/or causing scale build-up. Since it is often labor
intensive and expensive to coat electrodes with these precious
metals such as iridium, ruthenium, palladium, rhodium, and
platinum, it is desirable to stamp the profile of the electrode
after it has been coated with these precious metals. Careful
arrangement of the electrode design can allow for an exit edge to
remain coated after blanking the coated sheet. With the exit edge
coated, the only other exposed edge of the electrode not in contact
with a polyethylene shroud is an inlet edge which can have a
suitable inlet grate fashioned so as to cap the inlet edge.
[0028] In yet another aspect of the present disclosure, a removable
electrolytic cartridge can be mounted within a flow system with a
means for mounting. In one embodiment, the means for mounting can
comprise a sump head such an electrode assembly is positioned
within an attached sump chamber. Alternatively, the means for
mounting can comprise a cartridge fitting such as, for example, an
elbow, "T" or other port assembly for mounting the electrode
assembly directly within a length of conduit for inline
operation.
[0029] The above summary of the invention is not intended to
describe each illustrated embodiment or every implementation of the
present invention. The Figures and the Detailed Description that
follow more particularly exemplify these embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] The invention can be more completely understood in
consideration of the following detailed description of various
embodiments of the invention in connection with the accompanying
drawings, in which:
[0031] FIG. is a rear, perspective view of a representative
axial-flow sump electrolysis chamber according to an embodiment of
the present disclosure.
[0032] FIG. 2 is a side view of an outlet side of the axial-flow
sump electrolysis chamber of FIG. 1.
[0033] FIG. 3 is a section view of the axial-flow sump electrolysis
chamber of FIG. 1 taken at line A-A of FIG. 2.
[0034] FIG. 4 is a top view of the axial-flow sump electrolysis
chamber of FIG. 1.
[0035] FIG. 5 is an exploded, top perspective view of an axial-flow
sump and a removable electrode cartridge according to an embodiment
of the present disclosure.
[0036] FIG. 6 is a rear, perspective view of the axial-flow sump
electrolysis chamber of FIG. 1 with a plug assembly shown detached
from a removable electrode cartridge according to an embodiment of
the present disclosure.
[0037] FIG. 7 is a rear, perspective view of the axial-flow sump
electrolysis chamber of FIG. 1 with a sump housing shown detached
from a sump head according to an embodiment of the present
disclosure.
[0038] FIG. 8 is an exploded, perspective view of a representative
embodiment of a removable electrode cartridge according to the
present disclosure.
[0039] FIG. 9 is a section view of the axial-flow sump electrolysis
chamber of FIG. 1 taken at line B-B of FIG. 4.
[0040] FIG. 10 is a section view of axial flow sump electrolysis
chamber of FIG. 1 taken at Detail C of FIG. 9.
[0041] FIG. 11 is a bottom, perspective view of a representative
embodiment of a removable power plug according to the present
disclosure.
[0042] FIG. 12 is an exploded, top perspective view of a flow
assembly for mounting a removable electrolytic cartridge directly
within a fluid conduit according to an embodiment of the present
disclosure.
[0043] While the invention is amenable to various modifications and
alternative forms, specifics thereof have been shown by way of
example in the drawings and will be described in detail. It should
be understood, however, that the intention is not to limit the
invention to the particular embodiments described. On the contrary,
the intention is to cover all modifications, equivalents, and
alternatives falling within the spirit and scope of the invention
as defined by the appended claims.
DETAILED DESCRIPTION OF THE DRAWINGS
[0044] Referring to FIGS. 1, 2, 4, 6, 7, a representative
embodiment of an axial-flow electrolytic cell 100 generally
comprises a sump assembly 102, a removable electrolytic cartridge
104 and a plug assembly 106. Axial-flow electrolytic cell 100 is
generally mountable within a fluid flow system by coupling the sump
assembly 102 to a flow inlet line 108 and a flow outlet line 110.
In a preferred embodiment, flow inlet line 108 and flow inlet line
110 are aligned in a generally axial orientation.
[0045] As illustrated in FIGS. 3, 7 and 9, sump assembly 102
generally comprises a sump head 120 and a sump chamber 122. Sump
head 120 generally includes a head body 124 having a sump mounting
width 125. Head body 124 includes an inlet flow port 126 and an
outlet flow port 128. Sump head 120 can include one or more
connectors 129 for retainably engaging the flow inlet line 108 to
the inlet flow port 126 and the outlet flow line 110 to the outlet
flow port 128. Connector 129 can comprise a u-clip retention
feature to enable fittings for PVC, pipe, copper, or PEX tubing as
desired for easily removable connections that are free of stresses.
The head body 124 can comprise a head perimeter wall 130 having an
upper perimeter portion 132 and a lower perimeter portion 134. A
lower head flange 136 is defined at the interface between the upper
perimeter portion 132 and the lower perimeter portion 134. The
lower perimeter portion 134 can include a lower exterior thread
136. The head perimeter wall 130 defines an upper head surface 138
and a lower head surface 140. A cartridge aperture 142 extends
continuously between the upper head surface 138 and the lower head
surface 140. Surrounding the cartridge aperture 142 on the upper
head surface 138 is an upper recess 144. A capture plate 146 can be
mounted within the upper recess 144 using fasteners 148. Sump head
120 generally comprises a molded assembly formed of a suitable
polymer material such as, for example, ABS, PVC, and PPO and the
like.
[0046] Sump chamber 122 can have a generally cylindrical perimeter
wall 150 defining an internal sump volume 152. The cylindrical
perimeter wall 150 extends between an upper chamber surface 154 and
a lower chamber surface 156. A chamber opening 158 is defined at
the upper chamber surface 154. Proximate the upper chamber surface
154, the sump chamber 122 can include an internal chamber thread
160. Sump head 120 comprises a molded assembly and can be formed of
a suitable polymer material including, for example, ABS, PVC, and
PPO and the like. In one preferred embodiment, sump chamber 122 is
molded of a transparent polymer such that fluid flow can be viewed
through the cylindrical perimeter wall 150.
[0047] Referring to FIGS. 5 and 8, removable electrolytic cartridge
104 generally comprises a cartridge head 170, an electrode sleeve
171 and an electrode assembly 172. Cartridge head 170 has a
mounting body 174 defining an upper cartridge surface 176, a
perimeter cartridge surface 178 and a lower cartridge surface 180.
Projecting outwardly from perimeter cartridge surface 178 is one or
more cartridge attachment tabs 182. Perimeter cartridge surface 178
can further comprise a cartridge sealing groove 184 for
accommodating a cartridge sealing member 186. Perimeter cartridge
surface 178 defines a cartridge inlet 188. A connection recess 192
is formed within the upper cartridge surface 176. Lower cartridge
surface 180 can comprise one or more cathode apertures 194 and one
or more anode apertures 196 that extend into the connection recess
192.
[0048] Electrode sleeve 171 generally comprises a rectangular
perimeter 200 that resembles the size and shape of electrode
assembly 172. Electrode sleeve 171 includes a hollow sleeve
interior 174 that extends between an upper sleeve surface 202 and a
lower sleeve surface 204. Proximate the upper sleeve surface 202,
electrode sleeve 171 includes a sleeve inlet aperture 206.
[0049] As illustrated in FIGS. 8, 9 and 10, electrode assembly 172
generally comprises a stacked arrangement of individual electrode
blades 210. Each individual blade 210 includes a conductor end 212
with a cathode 214 and an anode 216. The arrangement of the
individual cathodes 214 and electrodes 216 is alternated with each
individual electrode layer. Each electrode blade 210 has an
electrode length 218 and an electrode width 220. In order to
promote efficiency, an aspect ratio defined as electrode width 220
divided by electrode length 218 can be greater than 0.25. In one
representative embodiment, each individual blade 210 can have
electrode length 218 equal to 5.25'' with electrode width 220 being
equal to 1.50'' to provide an aspect ratio of 0.29
(1.50/5.25=0.29). In this embodiment, electrode blade 210 is
approximately 3.5 times as long as it is wide which shortens the
length along the electrode blade 210 that scale needs to be
scavenged and limits the size of the resulting bubble formations as
they coalesce and grow along each electrode blade 210. Each
electrode blade 210 generally comprises a titanium based coated
with a precious metal such as, for example, iridium, ruthenium,
palladium, rhodium, and platinum. Preferably, electrode length 218
exceeds the sump mounting width 125 so as to increase the amount of
the exposed electrode surface beyond the space required for
mounting the axial-flow electrolytic cell 100 within a flow
system.
[0050] Generally, removable electrolytic cartridge 104 is
fabricated by molding the cartridge head 170 of a non-conductive
polymer material such as, for example, ABS, PVC, and PPO. For
compatibility purposes, it can be advantages to mold the cartridge
head 170 and sump head 120 of the same material. Due to its
proximity to the electrode assembly 172, electrode sleeve 171 is
preferably molded of a scale-resistant polymer such as, for
example, polyethylene. Electrode assembly 172 is attached to the
cartridge head 170 by inserting the cathodes 214 and anodes 216 on
conductor end 212 into the corresponding one or more cathode
apertures 194 and one or more anode apertures 196 on lower
cartridge surface 180 such that cathodes 214 and anodes 216 are
exposed in connection recess 192. The cathodes 214 and anodes 216
can be potted with an appropriate potting agent such as epoxy,
urethane, or acrylic. In some embodiments, cathodes 214 and anodes
216 can be insert molded into the cartridge head 170. Electrode
sleeve 170 can be slidably advanced over the electrode assembly 172
such that upper sleeve surface 202 engages the lower cartridge
surface 180 and sleeve inlet aperture 206 aligns with cartridge
inlet 188. The edges of each electrode blade 210 can be in direct
contact with the electrode sleeve 171 such that no flow
disturbances are created in the region of the electrode blades 210
so as to avoid turbulent flow and potential scale precipitation. It
is also possible to have the edges of the electrode blades 210
spaced a small distance from the interior walls of the electrode
sleeve 171 as long as the edges are masked by a suitable coating
such as the precious metals of iridium, ruthenium, palladium,
rhodium, and/or platinum. This small spacing or gap will also
reduce the interaction of materials from precipitating or
collecting and scale buildup. Alternatively, the edges can be
coated in a material which prevents fluid contact such as a plastic
or glass insulator.
[0051] Referring to FIG. 11, plug assembly 106 generally comprises
a plug body 230 and a plug wire 232. Plug body 230 has a plug
perimeter wall 234, an upper plug surface 236 and a lower plug
surface 238. Lower plug surface 238 includes one or more electrical
contacts 240 for engaging and supplying power to cathodes 214 and
anodes 216. Plug body 230 is constructed such that plug perimeter
wall 234 substantially resembles the shape of connection recess 192
such that plug body 230 is slidably insertable and snugly retained
within the connection recess 192. With plug body 230 retained
within connection recess 192, electrical contacts 240 are
electrically engaged to cathodes 214 and anodes 216. The plug
assembly 106 has a 3.times.2 conductor array to connect to (5)
separate electrodes; (2) anodes 216 and (3) cathodes 214. It should
be understood that during polarity reversal schemes, the electrodes
are constructed and coated with identical materials such that anode
216 can become cathode 214 as the voltage and current are reversed
for scale cleaning. The plug can be configured symmetrically for an
even number of electrodes, or asymmetrical as desired to fit any
electrode geometry. While plug assembly 106 provides for easy and
quick replacement of removable electrolytic cartridges 104, some
embodiments of cartridge head 170 can include the plug wire 232 and
electrical contacts 240 formed as integral components of the
cartridge head 170.
[0052] Generally, axial flow electrolytic cell is assembled by
first assembling the sump assembly 102, attaching the removable
electrolytic cartridge 104 and finally connecting the plug assembly
106. To assembly the sump assembly 102, the sump chamber 122 is
positioned such that the upper chamber surface 154 is proximate the
lower perimeter portion 134 of the sump head 120. The lower
perimeter portion 134 is inserted into the chamber opening 158 such
that the lower exterior thread 136 engages the internal chamber
thread 160. By rotating the sump chamber 122 relative to the sump
head 120, the lower exterior thread 136 and the internal chamber
thread 160 interface and engage to retainably connect the sump head
120 and sump chamber 122. As the sump head 120 and sump chamber 122
are connected, a sump seal member 240 can be compressed between the
lower perimeter portion 134 and a thread flange 242 proximate the
internal chamber thread 160 to prevent leakage under typical
operation pressures.
[0053] Once the sump assembly 102 is sealably connected, the
removable electrolytic cartridge 104 can be coupled to the sump
head 120. Removable electrolytic cartridge 104 is arranged such
that lower sleeve surface 204 is proximate the cartridge aperture
142 as seen in Figure XX. Electrode sleeve 171 is advanced through
the cartridge aperture 142 such that lower sleeve surface 204
enters the internal sump volume 152. Cartridge head 170 is
constructed such that mounting body 174 fits snugly within the
cartridge aperture 142. As lower sleeve surface 204 approaches the
lower chamber surface 156, cartridge sealing member 186 is
compressed against the sump head 120 to provide a liquid tight seal
under typical operating pressures. Lower sleeve surface 204 is
spaced apart from the lower chamber surface 156 with enough
clearance to hold any temporary scale which might collect during
operation at low flow rates. Cartridge attachment tabs 182 enter
the cartridge aperture 142, whereby a turn of the removable
electrolytic cartridge 104 results in the positive capture of the
cartridge attachment tabs 182 below the capture plate 146. With the
cartridge attachment tabs 182 positioned below the capture plate
146, the removable electrolytic cartridge 104 is retainably coupled
to the sump assembly 102. In a preferred embodiment, the cartridge
attachment tabs 180 and capture plate 146 define a bayonet style
capture mechanism where a quarter turn of the removable
electrolytic cartridge 104 results in successful engagement of the
removable electrolytic cartridge 104 and the sump assembly 102. In
some embodiments, cartridge aperture 142 can include one or more
kick-off ramps to allow for a camming action as the cartridge
attachment tabs 182 engage the capture plate 146. One particular
benefit of straight attachment tabs 182 as opposed to threads is
that any pressure which would push outward on the removable
electrolytic cartridge 104 does not result in back-driving of the
removable electrolytic cartridge 104 and potential disconnection at
operating pressures. In the event that a removable electrolytic
element 104 has reached the end of it useful service life, removal
is the reverse of the installation and a second, identical
removable electrolytic element 104 can be installed to continue
operation.
[0054] Once the removable electrolytic cartridge 104 is attached to
the sump assembly 102, the plug assembly can be attached to the
removable electrolytic cartridge 104 by positioning the plug body
230 within the connection recess 192 with the lower plug surface
238 arranged such that electrical contacts 240 are electrically
engaged to cathodes 214 and anodes 216. Finally, plug wire 232 can
be coupled to a power source such that power can be supplied to the
electrode assembly 172 and electrolysis can be accomplished along
electrode blades 210.
[0055] Generally, axial-flow electrolytic cell 100 is installed
within a fluid system by coupling flow inlet line 108 to an inlet
conduit and the flow outlet line 110 to an outlet conduit. A fluid
stream 300 to be treated enters the inlet line 108, flows though
the inlet flow port 126 and into the cartridge inlet 188 as
illustrated in FIG. 3. From cartridge inlet 188, fluid stream 300
is directed into the electrode sleeve 171 though the sleeve inlet
aperture 206. Once inside the electrode sleeve 171, fluid stream
300 is directed downwards along electrode blades 210 where
electrolysis and the generation of oxygen and hydrogen bubbles
occur. Fluid stream 300 flows along the major axis or electrode
length 218 and is forced between the individual electrode blades
210 such that the fluid stream 300 is fully exposed to the
electrical influence of the electrolytically generated oxidation
and reduction activity. Fluid steam 300 is bounded by the sides of
each electrode blade 210 and the electrode sleeve 171. Fluid stream
300 exits electrode sleeve 171 at the lower sleeve surface 204 and
is forced to make a 180 degree toroidal turn which serves to mix
the fluid stream 300. Within the sump chamber 122, the fluid stream
300 experiences additional contact time with the electrolytically
generated gases oxygen until the fluid stream exits the sump
chamber 122 through the outlet flow port 128 and out the flow
outlet line 110. After fluid stream 300 is treated by the
axial-flow electrolytic cell 100, the fluid stream 300 can be
directed to points of use or through additional filtering means to
remove any precipitated contaminants resulting from the
electrolysis reactions. If during operation, scale begins to
accumulate within the sump chamber 122, the axial-flow electrolytic
cell 100 can be backwashed with fluid stream 300 running in a
reverse direction to remove scale.
[0056] With the rotatably connectable design of axial-flow
electrolytic cell 100, it will be understood that various capacity
modifications can be made without substantially altering the system
design. For instance, sump chamber 122 can be replaced with second
sump chamber 122 having a similar diameter but a longer overall
sump to increase the internal sump volume 152. With a large
internal sump volume 152, a second removable electrolytic cartridge
104 having an electrode assembly 172 with electrode blades 210
having an increased electrode length 218 can be attached to the
sump head 120. In this manner, capacity or electrolytic performance
can be varied without impacting connection of the sump head 120 or
the plug assembly 106.
[0057] Referring now to FIG. 12, removable electrolytic cartridge
104 can be employed directly within a fluid conduit as part of an
inline flow system 400. Generally inline flow system 400 comprises
an upstream fluid conduit 402, a downstream fluid conduit 403, a
cartridge fitting 404, the removable electrolytic cartridge 104 and
the plug assembly 106. As shown in FIG. 12, cartridge fitting 404
can comprise an orientation that allows the electrode sleeve 171 to
be positioned directly within a conduit flow stream so as to
provide the benefits of electrolysis directly within the flow
stream and the conduit. In some embodiments, cartridge fitting 404
can comprise an elbow body 406 having an elbow inlet 408 and an
elbow outlet 410. Alternatively, cartridge fitting 404 can comprise
other suitable configurations including, for example, T's, and
various pipe port designs. The elbow body 406 comprises a mounting
surface 412 including a cartridge attachment aperture 414. A
retention plate 416 can be mounted to the mounting surface 412 with
fasteners 418. The removable electrolytic cartridge 104 is attached
to the cartridge fitting 404 in the same manner as removable
electrolytic cartridge 104 was attached to the sump head 120.
Specifically, the electrode sleeve is slidably inserted into the
cartridge attachment aperture 414 such that the electrode sleeve
171, and consequently, the electrode assembly 172 is positioned
directly within the upstream fluid conduit 402. Use of the
cartridge fitting 404 provides for a space saving installation
while providing for quick and easy change out of spent electrodes
in an inline flow arrangement with the removable electrolytic
cartridge 104.
[0058] Although specific examples have been illustrated and
described herein, it will be appreciated by those of ordinary skill
in the art that any arrangement calculated to achieve the same
purpose could be substituted for the specific examples shown. This
application is intended to cover adaptations or variations of the
present subject matter. Therefore, it is intended that the
invention be defined by the attached claims and their legal
equivalents.
* * * * *