U.S. patent application number 11/123144 was filed with the patent office on 2006-11-09 for electrochemical cell with elastomeric cap.
Invention is credited to Walid Abi Aoun, David Edward Cross.
Application Number | 20060249375 11/123144 |
Document ID | / |
Family ID | 37393109 |
Filed Date | 2006-11-09 |
United States Patent
Application |
20060249375 |
Kind Code |
A1 |
Aoun; Walid Abi ; et
al. |
November 9, 2006 |
Electrochemical cell with elastomeric cap
Abstract
An electrochemical cell having co-axial inner and outer
electrodes separated by an ion-permeable tube that defines inner
and outer passageways for liquid flow lengthwise of the electrodes.
The ion-permeable tube has elastomeric caps attached at each end.
The elastomeric caps have rims that engage the inner walls of the
electrochemical cell to separate the inner and outer passageways
and the electrochemical products derived at the inner and outer
electrodes.
Inventors: |
Aoun; Walid Abi; (Wantage,
GB) ; Cross; David Edward; (West Sussex, GB) |
Correspondence
Address: |
KENYON & KENYON LLP
1500 K STREET N.W.
SUITE 700
WASHINGTON
DC
20005
US
|
Family ID: |
37393109 |
Appl. No.: |
11/123144 |
Filed: |
May 6, 2005 |
Current U.S.
Class: |
204/260 |
Current CPC
Class: |
C02F 2201/003 20130101;
C02F 2001/46152 20130101; C25B 9/19 20210101; C02F 2001/46142
20130101; C02F 1/46109 20130101 |
Class at
Publication: |
204/260 |
International
Class: |
C25B 9/06 20060101
C25B009/06 |
Claims
1. An electrochemical cell comprising: opposing first and second
heads respectively having inlet ports and outlet ports, each of the
heads having an inner cylindrical wall; an outer electrode secured
to the opposing first and second heads; an inner electrode co-axial
with the outer electrode; an ion-permeable tube supported
co-axially between the inner electrode and the outer electrode to
define an inner passageway and an outer passageway, the
ion-permeable tube having a first and second end; and a first and
second elastomeric cap respectively attached to the first and
second end of the ion-permeable tube, the first and second
elastomeric cap having a rim respectively engaging the inner
cylindrical wall of the opposing first and second heads providing
liquid-tight sealing therewith and separating the inner and outer
passageways.
2. The electrochemical cell of claim 1, wherein the outer electrode
is a metal tube.
3. The electrochemical cell of claim 1, wherein the inner electrode
is a metal rod.
4. The electrochemical cell of claim 1, wherein the outer electrode
is a cathode and the inner electrode is an anode.
5. The electrochemical cell of claim 1, wherein the inner electrode
is a cathode and the outer electrode is an anode.
6. The electrochemical cell of claim 1, wherein the ion-permeable
tube is fabricated of a porous ceramic material.
7. The electrochemical cell of claim 1, wherein the first head is
one-piece and the second head is one-piece.
8. The electrochemical cell of claim 1, wherein the first
elastomeric cap is one-piece and the second elastomeric cap is
one-piece.
Description
BACKGROUND OF THE INVENTION
[0001] One use of electrochemical cells is purifying water and
producing disinfecting solutions. One type of electrochemical cell
that serves this purpose has co-axial inner and outer electrodes
separated by a co-axial ceramic tube, all of which are fixed in
opposing fittings or heads. The ceramic tube divides the cell into
an anode chamber and a cathode chamber. Each chamber has a channel
in fluid communication with an inlet port and an outlet port into
which electrolyte is supplied and from which the resulting treated
solution is discharged, respectively. In order to keep the channels
of the anode and cathode chambers separate, the electrochemical
cell often includes separators positioned between the inlet ports
of the anode and cathode chamber as well as between the outlet
ports of the anode and cathode chambers. One type of separator is
installed in slots on the butt-ends of fittings and fastened to the
ceramic tube. However, such a separator is difficult to install in
the tight space between the fitting and the ceramic tube and there
is danger of damaging the ceramic tube during assembly. Another
type of separator is a plastic O-ring that is placed around the
ceramic tube and that abuts the inner wall of the fittings. This
type of separator is also not ideal since it does not provide
optimal fitness around all types of ceramic tubes, particularly
ceramic tubes having a cross-sectional configuration that is not
precisely circular. Therefore, a need exists for an electrochemical
cell having a separator that does not damage any components of the
electrochemical cell during assembly and that has better sealing
properties.
SUMMARY OF THE INVENTION
[0002] In an embodiment, the present invention provides an
electrochemical cell comprising opposing first and second heads
respectively having inlet ports and outlet ports and each head
having an inner cylindrical wall. The electrochemical cell further
provides an outer electrode secured to the opposing first and
second heads and an inner electrode co-axial with the outer
electrode. An ion-permeable tube is supported co-axially between
the inner electrode and the outer electrode to define an inner
passageway and an outer passageway. Elastomeric caps are attached
to the ends of the ion-permeable tube. Specifically, the
elastomeric caps have rims which engage the inner cylindrical walls
of the opposing first and second heads to provide liquid-tight
sealing therewith and to separate the inner and outer
passageways.
BRIEF DESCRIPTION OF THE DRAWINGS
[0003] FIG. 1 is a cross-sectional view of an electrochemical cell
according to the present invention.
[0004] FIG. 2 is a side view of an electrochemical cell according
to the present invention.
[0005] FIG. 3 is a side view of an elastomeric cap according to the
present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0006] Referring to FIG. 1, in an embodiment, the present invention
provides an electrochemical cell 10 having opposing first and
second heads 20 and 30. First head 20 has an inner cylindrical wall
35 and an outlet port 40 and an outlet port 50. Second head 30
similarly has an inner cylindrical wall 60 and an inlet port 70 and
an inlet port 80. Preferably, first and second heads 20 and 30 are
cup-shaped with a stepped internal diameter that defines a first
cylindrical cavity part 140 and 150, respectively, into which inlet
port 70 opens and from which outlet port 50 opens, respectively.
Preferably, cavity part 140 and 150 lead, via respective annular
end-faces 160 and 165 into respective second cylindrical cavity
parts 170 and 180 of smaller diameter into which inlet port 80
opens and from outlet port 40 opens, respectively. Preferably,
first and second heads 20 and 30 are each "one-piece." As used
herein, the term "one-piece" means a single solitary piece that
does not have individual combinable components that can be
assembled together into a single unit.
[0007] Electrochemical cell 10 further comprises an outer electrode
90 having an end 100 secured in first head 20 and an end 110
secured in second head 30. For example, cavity parts 140 and 150
can have respective recessed mouths 161 and 162 that receive
respective ends 100 and 110 for liquid-tight sealing therewith. The
ends of the outer electrode can be lightly machined externally over
a short length (for example, 5 mm) so as to enable them to be
received by the respective mouths of the cavities.
[0008] Electrochemical cell 10 further comprises an inner electrode
120 co-axial with the outer electrode 90. Preferably, electrode 120
extends axially through both cavity parts 140 and 150 and both
cavity parts 170 and 180 of first and second heads 20 and 30
respectively, and has end portions 185 and 190 of reduced diameter.
Preferably, ends 185 and 190 project from respective cavity parts
170 and 180 into and through respective bores 200 and 210 of
respective heads 20 and 30. Preferably, there is an interference
fit between end portions 185 and 190 and respective bores 200 and
210. Referring to FIG. 2, preferably end portions 185 and 190 are
threaded to receive respective washers 219 and 229 and nuts 220 and
230, where end portions 185 and 190 project from respective heads
20 and 30. Nuts 220 and 230 are tightened to clamp the heads 20 and
30 firmly onto ends 100 and 110 of outer electrode 90 and to hold
ends 100 and 110 firmly to inner electrode 120 with inner electrode
120 and outer electrode 90 co-axial with one another.
[0009] The outer electrode of the present invention may be a metal
tube and the inner electrode of the present invention may be a
solid metal rod or a hollow metal tube. The metal involved in each
case may be titanium, however, where the electrode is for use as
the cathode of the cell it may, as an alternative, be fabricated of
stainless steel. Where the electrode is for use as an anode, it may
having a coating that acts as a catalyst in the electrochemical
operation of the cell, such as, for example, titanium oxide,
ruthenium oxide, or iridium oxide.
[0010] Referring back to FIG. 1, electrochemical cell 10 further
comprises an ion-permeable tube 130 supported co-axially between
inner electrode 120 and outer electrode 90. Ion-permeable tube 130
provides an intermediate ion-permeable membrane for separating the
products derived electrochemically at the two electrodes and, more
particularly, divides the space between inner electrode 120 and
outer electrode 90 into an inner passageway 145 and an outer
passageway 155. Inner passageway 145 terminates at inlet port 40 of
first head 20 and outlet port 80 of second head 30. Outer
passageway 155 terminates in outlet port 50 of first head 20 and
inlet port 70 of second head 30. The ion-permeable tube may be
porous and in this respect may be fabricated from ceramics made
from, for example, zirconium, aluminum and yttrium oxide and can
contain additives such as, for example, niobium oxide, tantalum
oxide, titanium oxide, gadolinium oxide, hafnium oxide and any
combination thereof. In a preferred embodiment, the ion-permeable
tube has the following specifications: TABLE-US-00001 Length (mm)
210 .+-. 0.5 Outer Diameter (mm) 11.5 + 0.3/-0.2 Thickness (mm) 0.7
+ 0.05/-0.1 Bow (mm) .+-.1 Weight (g) 9.5-12.0 Materials
Composition (% Mass) Alumina: 58-68 Zirconia: 27-37 Yttria: 1.3-3.3
Porosity (%) 42-62 Typical Pore Size (microns) 0.2-0.8 Three Point
Break Strength, Housfield 20-100 Tensometer (N) Hydraulic Cross
Flow (ml/min) 5-16
[0011] Of course, the above-listed specifications are only
preferred and other specifications of the ion-permeable tube are
within the scope of the present application.
[0012] Electrochemical cell 10 further comprises first and second
elastomeric caps 260 and 270 attached to respective first and
second ends 240 and 250 of ion-permeable tube 130. Referring to
FIG. 3, first elastomeric cap 260 has tubular body 281 integral
with a rim 280 and similarly second elastomeric cap 270 has a
tubular body 291 integral with a rim 290. Referring back to FIG. 1,
rim 280 engages inner wall 35 of first head 20 and similarly rim
290 engages inner wall 60 of second head 30. Such engagement of the
rims of the elastomeric caps with the inner walls of the heads
provides liquid-tight sealing therewith and separates the inner and
outer passageways. Furthermore, the elastomeric nature of the
elastomeric cap allows the cap to conform to cross-sectional
configurations of ion-permeable tubes that are not precisely
cylindrical. Referring to FIG. 3, preferably elastomeric cap
260/270 has internal sealing rings 300 which secure elastomeric cap
260/270 on the ends of ion-permeable tube 130. Preferably,
elastomeric cap 260/270 is one-piece.
[0013] The extent of the projection of ion-permeable tube 130
beyond the ends 100 and 110 of outer electrode 90 within each head
20 and 30 ensures that each elastomeric cap 260 and 270 is located
deeper within the respective cavity 140 and 150 than respective
ports 50 and 70 so that elastomeric caps 260 and 270 maintain
appropriate separation of respective ports 50 and 70 from
respective cavities 170 and 180 and respective ports 40 and 80.
[0014] Referring back to FIG. 3, preferably rim 280/290 of
elastomeric cap 260/270 has a length L of between about 13-14
millimeters (mm) and more preferably a length L of 13.75 mm.
Preferably body 281/291 has a length L.sub.1 of between about 12-13
mm and more preferably a length L.sub.1 of 12.9 mm. Preferably,
elastomeric cap 260/270 has a width W of between about 5-7 mm and
more preferably a width W of 6 mm. Elastomeric cap 260/270 can be
fabricated of any suitable elastomer such as, for example,
silicone; rubber; thermoplastic elastomers such as thermoplastic
vulcanizates, including polypropylene-ethylene propylene diene
terpolymer; or polyurethane.
[0015] The foregoing description has been set forth merely to
illustrate the invention and is not intended as being limiting.
Each of the disclosed aspects and embodiments of the present
invention may be considered individually or in combination with
other aspects, embodiments, and variations of the invention. In
addition, unless otherwise specified, none of the steps of the
methods of the present invention are confined to any particular
order of performance. Modifications of the disclosed embodiments
incorporating the spirit and substance of the invention may occur
to persons skilled in the art and such modifications are within the
scope of the present invention. For example, first and second heads
20 and 30 could be interchanged such that first head 20 has an
inlet port 40 and an inlet port 50 and second head 30 has an outlet
port 70 and an outlet port 80. Furthermore, all references cited
herein are incorporated by reference in their entirety.
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