U.S. patent application number 13/324714 was filed with the patent office on 2013-06-13 for dual diaphragm electrolysis cell assembly and method for generating a cleaning solution without any salt residues and simultaneously generating a sanitizing solution having a predetermined level of available free chlorine and ph.
The applicant listed for this patent is Ralph A. Lambert, Michael van Schaik. Invention is credited to Ralph A. Lambert, Michael van Schaik.
Application Number | 20130146473 13/324714 |
Document ID | / |
Family ID | 47630505 |
Filed Date | 2013-06-13 |
United States Patent
Application |
20130146473 |
Kind Code |
A1 |
Lambert; Ralph A. ; et
al. |
June 13, 2013 |
Dual diaphragm electrolysis cell assembly and method for generating
a cleaning solution without any salt residues and simultaneously
generating a sanitizing solution having a predetermined level of
available free chlorine and pH
Abstract
An Electrolysis cell assembly to produce diluted Sodium
Hydroxide solutions (NAOH) and diluted Hypochlorous Acid (HOCL)
solutions having cleaning and sanitizing properties. The
electrolysis cell consists of two insulating end pieces for a
cylindrical electrolysis cell comprising at least two cylindrical
electrodes with two cylindrical diaphragms arranged co-axially
between them. The method of producing different volumes and
concentrations of diluted NAOH solutions and diluted HOCL solutions
comprises recirculating an aqueous sodium chloride or potassium
chloride solution into the middle chamber of the cylindrical
electrolytic cell and feeding softened filtered water into the
cathode chamber and into the anode chamber of the cylindrical
electrolysis cell.
Inventors: |
Lambert; Ralph A.;
(Gettysburg, PA) ; van Schaik; Michael;
(Loxahatchee, FL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Lambert; Ralph A.
van Schaik; Michael |
Gettysburg
Loxahatchee |
PA
FL |
US
US |
|
|
Family ID: |
47630505 |
Appl. No.: |
13/324714 |
Filed: |
December 13, 2011 |
Current U.S.
Class: |
205/510 ;
205/334; 205/556 |
Current CPC
Class: |
C02F 2201/46115
20130101; C02F 2201/4618 20130101; C02F 1/4618 20130101; Y02P
20/129 20151101; C02F 2201/003 20130101; C25B 1/26 20130101; Y02P
20/20 20151101; C25B 9/08 20130101 |
Class at
Publication: |
205/510 ;
205/334; 205/556 |
International
Class: |
C25B 1/16 20060101
C25B001/16; C25B 1/26 20060101 C25B001/26; C25B 1/00 20060101
C25B001/00 |
Claims
1. A method of making electrolyzed liquids utilizing an
electrolysis cell comprising an outer cylindrical electrode
separated from an inner cylindrical electrode by two cylindrical
diaphragms arranged coaxially one within the other to create a
cathode chamber, a middle chamber and an anode chamber; providing a
pair of end pieces where the space between the inner tubular
electrode and the membrane and the space between the membrane and
the outer tubular electrode defines anode and cathode chambers;
where the space between the diaphragms defines the electrolyte
chamber and where one of the electrodes functions as an anode and
the other electrode functions as a cathode; providing a saturated
brine solution to the middle chamber of the electrolysis cell and
providing softened water to the anode and cathode chamber applying
a current across the electrodes, wherein each end piece provides a
sealing engagement between the four sections of the end piece and
each of the cylindrical electrodes and the two cylindrical
diaphragms, wherein the end piece has a lateral inlet through an
outer wall thereof, said inlet being provided with a fitting for
tangential feeding of the liquid to the inside of the end piece,
and wherein three pairs of ports for entrance or exit of fluid are
situated in the upper and lower end piece, each comprising an
external fitting for attachment of a hose or pipe, wherein said
first pair of ports at opposite ends of said assembly internally
addresses a space between said outer electrode tube and said outer
diaphragm and said second pair of ports at opposite ends of said
assembly internally addresses a space between said outer diaphragm
and said inner diaphragm and said third pair of ports at opposite
ends of said assembly internally addresses a space between said
inner electrode tube and said inner diaphragm.
2. The method of claim 1, wherein the two diaphragms are a
cylindrical ceramic membrane or a cylindrical polymer ion exchange
membrane.
3. The method according to claim 1, wherein the anode and cathode,
or both, comprise a titanium base activated with a mixed metal
oxide coating structure comprising ruthenium, iridium, titanium,
tantalum, rhodium and mixtures thereof.
4. The assembly of claim 1, wherein said end piece comprises four
stackable sections of complimentary topography with at least one
seal forming feature at every interface between adjacent sections
wherein said seal forming feature is a sealant or compressible
ridge, a gasket, or an O-ring.
5. The assembly of claim 4, wherein the end pieces comprise
Polyvinyl Chloride (PVC), said gaskets and O-rings comprised of
Ethylene Propylene (EPDM), Nitrile (BUNA-N), Fluorocarbon (FKM any)
or combination of a plastic and a rubber.
6. The method of claim 1, wherein an electrolyte is circulated
through the middle chamber is a sodium chloride solution or a
potassium chloride solution.
7. The method of claim 1, where the electrolyte is saturated by
circulating the electrolyte through an intermediate chamber lined
with sodium chloride or potassium chloride and where the
intermediate chamber can be opened to fill the reservoir with
granular sodium chloride or granular potassium chloride and whereas
the intermediate chamber is an external brine reservoir and not
part of the cylindrical electrolysis cell.
8. The method of claim 7, whereas the electrolyte is circulated
between the middle chamber and the brine reservoir using a variable
speed peristaltic pump and where said pump being in communication
with the reservoir through a main feed line made from a flexible
and resilient material and to the middle chamber.
9. The method of claim 7, whereas the intermediate chamber is
pressurized with softened water and whereas the electrolyte in
intermediate chamber can be drained by opening a valve.
10. The method of claim 1, wherein the liquid is brine and the
method further comprises, isolating an alkaline cleaning liquid
having a negative redox potential ranging from 600 to 1200 mV.
11. The method of claim 1, wherein the liquid is brine and the
method further comprises, isolating an acidic sanitizing solution
having a positive redox potential ranging from 600 to 1200 mV.
12. The method of claim 1, wherein a portion of the liquid exiting
the cathode chamber is fed into the anode chamber and another
portion collected in a storage tank or drained.
13. The method of claim 1, wherein a part of the diluted Sodium
Hydroxide solution (NAOH) is fed successively through the anode
chamber to produce a more neutral pH Hypochlorous Acid solution
(HOCL).
14. The method of claim 13, wherein the pH of the sanitizing
solution is regulated by re-directing a volume of Sodium Hydroxide
(NAOH) through the anode chamber.
15. The method of claim 1, wherein softened water is supplied to
both the anode chamber and cathode chamber at a lower end piece of
the electrolysis cell and cleaning solutions (NAOH) and sanitizing
solutions (HOCL) are obtained from an upper end piece of the
cell.
16. The method of claim 1, wherein a spiral feed of the softened
water is fed to the anode and cathode chamber using tangential
inlet and outlet ports and a spiral fed of electrolyte is fed into
the middle chamber using tangential inlet and outlet ports.
17. The method of claim 1, wherein the current is a direct current
is applied across the electrodes.
18. The method of claim 1, wherein the free available chlorine
content is regulated by altering the voltage, volume of softened
water through the anode chamber and cathode chamber, brine
concentration and whereas the current across the electrodes is at
least 20 amps.
19. The assembly of claim 1, wherein the cathode chamber comprises
an inlet fitting connected to a tube that passes tangentially
through a specific section of the lower end piece to communicate
with the cathode chamber through an aperture and wherein the anode
chamber comprises an inlet fitting connected to a tube that passes
tangentially through a specific section of the lower end piece to
communicate with the cathode chamber through an aperture
20. The assembly of claim 19, wherein a specific section of the
lower end piece comprises an inlet fitting connected to a pipe that
passes through the specific section of the lower end piece to
communicate with the middle chamber through an aperture.
21. The assembly of claim 1, wherein the cathode chamber comprises
an outlet fitting connected to an tube that passes tangentially
through a specific section of the upper end piece to communicate
with the cathode chamber through an aperture and wherein the anode
chamber comprises an outlet fitting connected to a tube that passes
tangentially through a specific section of the upper end piece to
communicate with the cathode chamber through an aperture.
22. The assembly of claim 21, wherein a specific section of the
upper end piece comprises an outlet fitting connected to a pipe
that passes through a specific section of the upper end piece to
communicate with the middle chamber through an aperture.
23. The assembly of claim 1, wherein said ports address said spaces
through said end pieces or through said electrode tubes adjacent to
the site of insertion of said electrode tubes into said end
pieces.
24. The assembly of claim 1, wherein said entrance ports direct the
flow of said fluid at an angle of 0 to 15 degrees relative to the
plane of said seats of said end pieces.
25. The method of claim 1, where the generated diluted Sodium
Hydroxide as cleaning solution is suitable for cleaning all
surfaces, including textiles, fabrics and carpets.
26. The method of claim 1, where the generated diluted Hypochlorous
Acid as sanitizing solution is suitable for sanitizing all hard
surfaces including glass, mirrors, plastics, wood, ceramic,
granite, metals and laminate.
27. The method of claim 1, where the generated cleaning and
sanitizing solution contains no salt residues due to the fact that
the electrolyte is circulated in the middle chamber and no
electrolyte is fed into the cathode chamber and no electrolyte is
fed into the anode chamber.
28. The method of claim 27, wherein the absence of salt residue
means that no residue will appear on surfaces including fabrics
that are cleaned and sanitized with the generated diluted Sodium
Hydroxide and diluted Hypochlorous Acid solutions.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a cylindrical electrolysis
cell assembly for producing simultaneously a diluted Sodium
Hydroxide and diluted Hypochlorous Acid solution for usage as
cleaning and sanitizing solutions by electrolysis of an aqueous
saline solution. The method comprising a cathode chamber, an
electrolyte chamber and an anode chamber separated by two
cylindrical diaphragms to prevent presence of salt residues in the
cleaning and sanitizing solutions and whereas pH and free available
chlorine content of the sanitizing solution can be altered.
BACKGROUND OF THE INVENTION
[0002] Electrolysis cells are used for the production of cleaning
and sanitizing solutions from brine. Also, electrolysis cells are
used to produce a sanitizing solution to disinfect water or other
media. Many types of electrolysis cells exist for these purposes.
The basic feature of these cells is two concentrically disposed
cylindrical electrodes with a diaphragm separating the space
between the two electrodes to define anode and cathode
compartments. An electrolyte, such as brine, is passed through the
anode and cathode compartments, separately or successively. When
brine is electrolyzed in this way, under suitable conditions, it
can produce a cleaning and sanitizing solution of high strength and
long shelf life, which is ecologically and human friendly.
[0003] Typically an electrolyte solution is passed through the
anode and cathode chambers separately to produce a diluted
Hypochlorous Acid solution as a sanitizing solution and a diluted
Sodium Hydroxide solution as a cleaning solution. Alternatively,
neutral sanitizing solutions can be produced when an electrolyte is
passed through the anode and cathode chambers successively.
[0004] The diaphragm is either made of a permeable ceramic or an
ion-exchange membrane. The diaphragm permits the diffusion of
electrolytes between the anode and cathode but retard the migration
of electrolysis products at the anode and cathode from diffusing to
each other reverting back to starting material or undesired side
products.
[0005] Acidic sanitizing solutions are generated by passing saline
through an electrolytic cell comprising an anode chamber, a cathode
chamber, and a separator. The result contains free available
chlorine (FAC) in the form of a mixture of oxidizing species,
predominantly Hypochlorous Acid (HOCl) and sodium hypochlorite, and
is characterized by its pH, FAC content, and redox level. Such
reactive species have a finite life and so, while the pH of the
solution will usually stay constant over time, its biocide efficacy
will decrease with age. Electrolysis cells either comprise
cylindrical electrodes plus one cylindrical ceramic diaphragm or
electrolysis cells comprise plate electrodes plus one ion permeable
sheet of membrane as separator.
[0006] Usage of insoluble ion permeable membranes or ceramic
diaphragms between the electrodes have been described for more than
100 years as, for example, that described in U.S. Pat. No. 590,826.
U.S. Pat. No. 914,856 describes a cell which permits the flow of
electrolyte solutions separately through the anode and cathode
compartments using concentric cylindrical electrodes with an ion
permeable diaphragm.
[0007] The three-chamber cell has the following merits. Reductive
species such as dissolved hydrogen gas produced in the cathode
chamber are likely to migrate into the anode chamber through the
diaphragm when utilizing a two chamber cell, such as described in
U.S. Pat. No. 7,374,645, U.S. Pat. No. 7,691,249 or in U.S. Pat.
No. 7,828,942. However, the middle chamber in the three-chamber
cell control the diffusion of reductive species from the cathode
chamber to the anode chamber and then the more strongly oxidative
anode water can be obtained.
[0008] In the cell shown in FIG. 1, the following electrolysis
reactions take place.
At the Anode:
[0009] 2H.sub.2O.fwdarw.2H.sup.++O.sub.2+2e.sup.- [1]
At the Cathode:
[0010] 2H++2e.sup.-.fwdarw.H.sub.2 [2]
[0011] These reactions increase the oxygen concentration in the
anode solution and the hydrogen concentration in the cathode
solution, while leaving the essential properties of electrolytic
water unchanged. Further, migration of hydrogen ions formed on the
anode toward the cathode is limited, and then the electrolysis
reaction [3] takes place in addition to the reaction [1] and
[2]:
H.sub.2O+2e.sup.-.fwdarw.1/2H.sub.2+OH.sup.- [3]
[0012] This reaction suggests that the pH of cathode water tends to
shift to the alkaline region. Hydrogen ions formed in the anode
chamber in the reaction [1] remain partly in that chamber. In the
two-chamber cell shown in FIG. 1 the anode solution, therefore, is
likely to be charged with the hydrogen ions, while the cathode
water is charged with hydroxide ions. In other words, the charged
water produced using electrolysis cell shown in FIG. 1 may not be
suitable for the surface cleaning such as glass, mirrors, metals or
treatment of semiconductors or resins.
[0013] In order to enhance the cleaning or surface treatment
efficacy, anode water is required to be more oxidative and/or
acidic and cathode water is required to be more reductive and/or
alkaline. However, the electrolysis cell shown in FIG. 1 is
difficult to produce the effective solutions.
[0014] The three-chamber cell shown in FIG. 2 is designed to solve
the problem mentioned above, where the middle chamber added between
the anode chamber and the cathode chamber. Using the three-chamber
cell easily electrolysis softened water.
[0015] Another merit of a three chamber cell is the fact that no
electrolyte is fed into the anode and cathode chamber. Although
efficiency of two chamber electrolysis cells has been significantly
improved, not all electrolytes that pass the cathode chamber are
conversed into Sodium Hydroxide. Likewise, not all electrolytes
that pass the anode chamber are conversed into Hypochlorous Acid
and/or Hypochlorite Ion.
[0016] As a result, both the cleaning and sanitizing solutions
generated in a two cell electrolysis cell contain salt residues.
Presence of salt in both the cleaning and sanitizing solutions
limit its usage for surface treatment, as salt is corrosive,
streaks the surface, and leaves deposits on the surface. As a
result, most cleaning and sanitizing procedures include an extra
rinse with potable water.
[0017] This invention resolves the deposits of salt and thus allows
for cleaning and sanitation of surfaces without additional
rinsing.
SUMMARY OF THE INVENTION
[0018] The invention is directed to a cylindrical dual diaphragm
electrolysis cell assembly comprising a cathode chamber,
electrolyte chamber, and an anode chamber. The present invention
provides an insulating end piece for a cylindrical electrolysis
cell of the type comprising at least two cylindrical electrodes
arranged coaxially one within the other with two cylindrical
diaphragms arranged coaxially between them.
[0019] Softened filtered water passed through the cathode chamber
functions as cleaning agent for all surfaces, fabrics, textiles,
and carpets. Softened filtered water passed through the anode
chamber functions as sanitizing agent for all hard surfaces.
[0020] Anodic electrolysis of softened water produces hydrogen
ions, where no anion is present as counter ion, unlike acidic
solutions prepared by adding acid such as hydrochloric acid or
sulfuric acid. The anode water produced by electrolyzing softened
water exhibits that the solution is charged. Moreover, the hydrogen
ion by itself is an electron acceptor and so exhibits one of
oxidizing species. So, the oxidation-reduction potential of anode
water tends to shift to noble side. In other words, the redox
sensor indicates a plus value. During cathodic electrolysis of
softened water is reduced at the cathode. This occurs because water
is more easily reduced than are sodium ions. Cathodic electrolysis
alters the H+/OH- balance around the cathode making the solution
more basic and the oxidation reduction potential of cathode becomes
negative.
[0021] When the two-chamber cell depicted in FIG. 1 is used, the
cathode water is not necessarily suitable for actual cleaning or a
surface treatment without rinsing the surface with distilled, RO or
tap water. The anode water is not necessarily suitable for
sanitizing hard surfaces without rinsing the surface afterwards
with distilled, RO or tap water. So improving the electrolysis cell
is very important to apply to actual use.
[0022] More specifically, the important factors for producing
effective cleaning and sanitizing agents are an apparent current
density (current (A)/apparent area of whole electrode (cm.sup.2), a
fluid velocity along the electrode surface, and a true current
density (effective current density=current (A)/true area of the
electrode (cm.sup.2)). As the fluid velocity increases, the
hydrogen ions and other electrolytic species produced on the
electrode surface migrate faster.
[0023] Various different sanitizing solutions can be produced in
the electrolysis cells of the present invention, depending on the
various flow patterns through the cell. For example, the softened
water can be fed to the anode and cathode chambers and the
electrolyzed solutions can then be collected from each of these
chambers separately. Alternatively, the softened water can be fed
through both the cathode and anode chambers successively. Other
factors which can be used to vary the sanitizing solution include
the voltage applied to the electrodes, the electrical power
absorbed, the electrode coating and physical size of the electrode,
the shape of the electrodes and distances between them and the
spacing and material of the membrane. The membrane material is also
an important feature since it affects the mobility of ions passing
between the electrodes.
[0024] An objective of the invention is to provide a cylindrical
electrolytic cell than can produce diluted Sodium Hydroxide and
simultaneously diluted Hypochlorous Acid whereas the pH and the
free chlorine content can be adjusted.
[0025] Another objective of the invention is to disclose a method
and apparatus that can prevent the presence of salt residues in
cleaning and sanitizing solutions whereas pH and free available
chlorine content of the sanitizing solution can be altered.
[0026] Another objective of the invention is to improve
cleanliness, as the cleaning solutions produced by the electrolytic
cell are effective for cleaning all surfaces by removing fine
particles or the like wherefrom and sanitizing solutions produced
by the electrolytic cell are effective for sanitizing all hard
surfaces by oxidation of micro-organism and viruses.
[0027] Yet another objective of the invention is to produce
cleaning and sanitizing solutions that are also effective for
cleaning and sanitizing resins or the like, in particular resins
for beverage, dairy, and even medical devices.
[0028] Yet still another objective of the invention is to produce
cleaning and sanitizing solutions wherein no special chemical
remains after cleaning and sanitizing.
[0029] Other objectives and further advantages and benefits
associated with this invention will be apparent to those skilled in
the art from the description, examples and claims which follow.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] FIG. 1 (prior art) is a view of a two chamber cylindrical
electrolysis cell as described in e.g. in U.S. Pat. No. 7,374,645,
U.S. Pat. No. 7,691,249, U.S. Pat. No. 7,828,942, or in U.S. Pat.
No. 8,002,955.
[0031] FIG. 2 is a view of a three chamber cylindrical electrolysis
cell assembly using two diaphragms to create a middle chamber
whereas electrolyte is circulated.
[0032] FIG. 3 (prior art) is a view of a typical two chamber
electrolysis cell assembly cut in a plane on the center axis
between the port to one electrode compartment in one end cap and
the port to the other electrode compartment in the other end
cap.
[0033] FIG. 4 is a view of a three chamber electrolysis cell
assembly cut in a plane on the center axis between the port to one
electrode compartment in one end cap and the port to the other
electrode compartment in the other end cap.
[0034] FIG. 5 (prior art) is a view of a one section end piece from
the side into which the tubes of a two chamber electrolysis cell
would be inserted.
[0035] FIG. 6 (prior art) is a view of a one section end plug with
only the inserted tubes cut in a plane of the center axis.
[0036] FIG. 7 is a view of a multiple section end piece from the
side into which the tubes of a three chamber electrolysis cell
would be inserted.
[0037] FIG. 8 is a view of a multiple section end piece from the
top of a three chamber electrolysis cell.
[0038] FIG. 9 (prior art) is a view of typical flow patterns in a
two chamber electrolysis cell.
[0039] FIG. 10 is a view of typical flow patterns in a three
chamber electrolysis cell.
[0040] FIG. 11 (prior art) is a view of alternative flow patterns
in a two chamber electrolysis cell.
[0041] FIG. 12 is a view of alternative flow patterns in a three
chamber electrolysis cell.
[0042] FIG. 13 is a view of the brine reservoir and peristaltic
pump to circulate the electrolyte.
DETAILED DESCRIPTION OF THE INVENTION
[0043] The present invention is directed to the construction of an
optimized cylindrical electrolysis cell that produces a cleaning
solution and simultaneously a sanitizing solution. The diluted
Sodium Hydroxide solution is more alkaline, contains no salt
residues and, therefore, the solutions can be used to clean any
surface without rinsing the surface afterwards with distilled, RO
water or tap water. The diluted Hypochlorous Acid solution contains
no salt residues and its free available chlorine content as well as
pH can be adjusted. As a result, surfaces can be effectively
sanitized using a sanitizing solution which pH and free available
chlorine is `tailored` to sanitize a certain surface taking into
account chlorine consumption and in line with various sanitizing
procedures as set by regulatory agencies such as the FDA, EPA, USDA
and CDC. Certain surfaces require a more acidic sanitizer whereas
other surfaces are damaged by the acid nature of the sanitizer. In
these cases, a more neutral pH Hypochlorous Acid is preferred.
Also, the absence of salt residues allows the use of the sanitizing
solution on any surface without rinsing the surface with distilled,
RO or tap water.
[0044] The three chamber electrolysis cell is illustrated in FIG. 2
and FIG. 4, where a cylindrical electrode [1] is positioned within
a cylindrical diaphragm [2] which is positioned within a second
cylindrical diaphragm [3], where the cylindrical diaphragm [3] is
positioned within a second cylindrical electrode [4] by the use of
two end pieces [99] which consist of a tube cap [6], port A cap
[7], port B cap [8] and port C cap [9].
[0045] The design of the four sections of the end piece [99]
permits the orientation and sealing of the entire assembly [100].
Tube cap [6] seals the outer electrode [4] with the end piece [99]
using an O-ring [12]. The tube cap [6] is either glued or screwed
on the outer electrode [4]. In case the tube cap [6] is screwed on
the outer electrode [4], the outer electrode tube-ends have a male
thread that fits a female thread manufactured in the tube cap
[6].
[0046] Port A cap [7] features port A for direction of the flow of
softened water through port A ending in fittings [17] into the
chamber A defined by the spaces between the anode [4] and the
diaphragm [3] and out of chamber A through port A ending in
fittings [17] of the opposite port A cap [6].
[0047] Port B cap [8] features port B for direction of the flow of
saturated brine through port B ending in fittings [17] into chamber
B defined by the spaces between the diaphragm [2] and diaphragm [3]
and out of chamber B through port B ending in fittings [17] of the
opposite port B cap [8].
[0048] Port C cap [9] features port C for direction of the flow of
softened water through port C ending in fittings [17] into chamber
C defined by the spaces between the inner electrode [1] and the
diaphragm [2] and out of chamber C through port C ending in
fittings [17] of the opposite port C cap [9].
[0049] The four sections of end piece [99] are either glued on each
other or compressed on each other using O-rings [13] to seal the
section on each other.
[0050] The tube cap [6] is either glued or screwed on the outer
electrode [4]. Port A cap [7] is either glued or pressed on the
tube cap [6] whereas the tube cap [6] facilitated a groove for an
O-ring [13] and whereas port A cap [7] is pressed on the tube cap
[6]. Port B cap [8] is either glued or pressed on port A cap [7]
whereas the port A cap [7] facilitated a groove for an O-ring [13]
and whereas the Port B cap [8] is pressed on port A cap [7]. Port C
cap [8] is either glued or pressed on port B cap [7] whereas port B
cap [7] facilitated a groove for an O-ring [13] and whereas port C
cap [8] is pressed on port B cap [7].
[0051] The tube cap [6], port A cap [7], port B cap [8] and port C
cap [8] are bolted together using three stainless steel bolts [18],
washers [19] and nuts [20]. In each section of the end piece [99],
there are three holes [21] to facilitate the stainless steel bolts
[18], washers [19] and nuts [20]. The seal between each section of
the end piece [99] is achieved by compressing the sections of the
end piece [99] onto each other, in a manner such that the
compressive force can be applied slowly and smoothly without the
introduction of torque such that a reliable seal is produced
without damaging the ceramic diaphragms [2] and [3].
[0052] Either of the electrodes [1] and [4] can act as the anode
with the other acting as the cathode. The choice can be made by
considerations of the ease of manufacture or requirements of the
nature of the electrolysis process to be performed which can favor
the anode or cathode chamber preferentially being the outer
chamber. These considerations include the desired spacing between
the electrodes and the diaphragms, the desired space between
diaphragm [2] and [3] and the relative volume requirements for the
balance of flows of the electrolyte solution in chamber B and the
softened water in chamber A and chamber C.
[0053] The inner electrode [1] and outer electrode [4] tubes are
constructed of an electrically conductive material, preferably
titanium.
[0054] The metal electrode tubes are coated with a mixed metal
oxide on the face of the tube directed toward the diaphragms [2]
and [3]. The metals of the two electrodes can be titanium or
stainless steel. Both metals can be coated with a mixed metal
oxide. The cathode can be an uncoated metal, but the anode has to
be a mixed metal oxide coated metal. A preferred arrangement has
the outside electrode tube [4] as the anode internally coated with
a mixed metal oxide and the inner electrode tube [1] as the cathode
and not coated.
[0055] The outer electrode [4] is shown in FIG. 2 with an
electrical connector [10] welded to the outside of the outer
electrode [4] tube. The inner electrode [1] has an electrical
connector [11] on its end that is part of the inner electrode [1]
and extends out of the outside of the upper end piece [99].
Although not necessary for the function of the assembly, the
outside of the outer electrode [4] is insulated by a rubber sleeve
[5] that is heat-shrinked over the outer electrode [4] and cut to
length. Another option is to glue an insulating sheath [5] or tube
on the outside of the outer electrode [4].
[0056] The anode and cathode are separated by two diaphragms [2]
and [3]. Preferably, these diaphragms are made of alumina,
zirconium containing ceramic. The thickness of the diaphragm can
vary over a broad range depending on the application the
electrolysis cell assembly [100] is to be used, the diaphragms [2]
and [3] are relatively fragile and a wall thickness of 1.5 to 2 mm
is preferred for most applications.
[0057] The relative diameter of the outer electrode [4], inner
electrode [1], diaphragms [2] and [3] can vary within the single
requirement that outer electrode [4] must be of greater diameter
than diaphragm [3], the diameter of diaphragm [3] greater than
diaphragm [2] and the diameter of diaphragm [3] greater than the
inner electrode tube [4]. The actual diameters can vary depending
upon the desired features of the electrolysis cell assembly [100].
To this end the diameters can be varied to optimize the rate of
electrolysis, rate of flow through the cell assembly, and other
needs of the system to which the assembly will be used. Likewise,
the relative length of the electrodes [1] and [4] and diaphragms
[2] and [3] can vary within the single requirement of this
embodiment that the outer electrode tube [4] must be shorter than
diaphragm [3], diaphragm [3] shorter than diaphragm [2] and
diaphragm [2] shorter than inner electrode [1]. The lengths of the
electrodes [1] and [4] and the length of the diaphragms [2] and [3]
can be determined by factors such as ease of construction and
geometries to optimize the performance of the electrolysis cell
assembly in the system in which it is to perform.
[0058] The upper and lower end pieces [99] are interchangeable and
constructed of an insulating material, preferably Polyvinyl
Chloride. Each end piece [99] consist of four sections, the tube
cap [6], Port A cap [7], Port B cap [8] and port C cap [9].
[0059] The four sections of the end piece [99] can be formed by
molding or machining. Ports [17] are for introduction or exit of
softened water to chamber A and to chamber C. Port [17] is for the
introduction and exit of electrolyte to chamber B. All sections of
the end piece [99] consist of three or more holes to accept three
or more stainless steel bolts [18], washers [19] and nuts [20] by
which the four sections of the end piece [99] are compressed
together.
[0060] Three sections [6], [7] and [9] of the end piece [99] have a
groove to facilitate O-ring [13] to form the seals between the end
piece sections. When the tube cap [6] is screwed on the outer
electrode [4] and stainless steel bolts [18], washers [19] and nuts
[20] are used, then the three bolts provide the structural
integrity of the assembly [100]. If the tube cap [6] is glued on
the outer electrode [4], then the three sections of the end piece
[99] are also glued together.
[0061] Two holes [22] with female thread are made in the tube cap
[6] at both opposite sides. This allows mounting the assembly [100]
on a plate or bracket. This plate or bracket may be a plastic or
stainless steel as long as the metal is insulated from one or both
of the electrodes. A preferred fabrication of a mounting plate or
bracket is a machined sheet of Polyvinyl Chloride, which is
commercially available as PVC.
[0062] One critical feature of the end piece [99] is that the
inside diameter of all sections of the end piece [99] closely match
the outside diameters of the four tubes [1], [2], [3] and [4] so
that when using glue as a sealant, a good seal can be achieved.
When screwing the tube cap [6] on the outer electrode [4] and when
the other sections of the end piece [99] are compressed on each
other, it is important that the O-rings [12], [14], [15] and [16]
form a good seal between the tubes [1], [2], [3] and [4] and the
four end caps [6], [7], [8] and [9] as well form a good seal
between the four sections themselves using O-ring [13]. The
relatively fragile diaphragms [2] and [3] require the use of
O-rings [14] and [15] to form the seal such that whilst assembling,
the diaphragms do not break. It is necessary that, upon assembly,
the length of the cell assembly [100] is defined by the length
imposed by the outer electrode tube [4]. The diaphragms [2] and [3]
must be long enough to seal at both ends by O-rings [14] and [15]
even if one end of the diaphragms [2] and [3] is resting on Port B
cap [8] and Port C cap [9].
[0063] A second critical feature of the end caps [99] is the
presence of three ports. Port A begins at fitting [17] on an
outside surface of Port A [7] permits the flow of softened water
through chamber A defined by the inside of the outer electrode tube
[4] and the outside of diaphragm [3] as illustrated in FIG. 2 and
FIG. 4. Port C begins at fitting [17] on an outside surface of Port
C cap [9] and permits the flow of softened water through chamber C
defined by the inside of diaphragm [2] and the outside of inner
electrode [1] as illustrated in FIG. 2 and FIG. 4. Port B begins at
the fitting [17] on an outside surface of port B cap [8] and
permits the flow of an electrolyte solution through chamber B
defined by the inside of diaphragm [3] and the outside diaphragm
[2], as illustrated in FIG. 2 and FIG. 3. The outside of port A,
port B and port C is a fitting [17] which accepts a tube for
introduction or exit of a fluid to the cell assembly [100].
[0064] These fittings [17] can be a compression fitting, as is
illustrated in FIG. 2 and FIG. 4, or it can be a hose barb or some
other coupling which is appropriate for the system within which the
electrolysis cell assembly [100] is to function. The orientation of
the portsis necessarily to promote a tight spiral flow around the
inner electrode tube [1], diaphragm [2] and [3] between the spaces
in chamber A, chamber B and chamber C.
[0065] The end pieces [99] can have other configurations as long as
the configuration permits for the sealing of the assembly where the
compressive force is imposed upon the outer electrode [4] and no
significant compressive force is imposed on the diaphragms [2] and
[3]. The different types of end pieces [99] can be combined in any
combination as long as the appropriate lengths of tubing are chosen
and as long as the sections of the end piece [99] can be sealed
together by compression or by using glue. While the preferred end
piece [99] has been illustrated and described, it will be clear
that the invention is not so limited. Modifications, changes,
variations, substitutions and equivalents will occur to those
skilled in the art without departing from the spirit and scope of
the present invention as described in the claims.
[0066] Another critical feature of this invention is the
construction of the brine reservoir [98] and the usage of a pump
[23] to circulate an electrolyte from the brine reservoir [98]
through chamber B to the brine reservoir [98] as shown in FIG. 13.
The brine reservoir [98] is preferably manufactured from a
transparent plastic tube [24] and two end pieces [25] and [26] made
of Polyvinyl Chloride, which is commercially available as PVC. The
transparent tube [24] is glued between end piece [25] and end piece
[26]. End piece [25] has a male thread that allows screwing a cap
[27] on top of end piece [25]. End piece [25] has also a port [28]
whereas through fitting [17] a tube can be connected for the exit
of the electrolyte to chamber B. End piece [26] has a port [29] on
the bottom of end piece [26] whereas through fitting [17] a tube
can be connected for the inlet of softened water. End piece [26]
has another port [30] on the bottom of end piece [26] with valve
[31]. Opening valve [31] allows drainage of the electrolyte from
the brine reservoir [98]. Ports [29] and [30] have been constructed
in such a way that the aperture of ports [29] and [30] is located
above the brine fill line. This feature is important for two
reasons. Firstly, when granular salt is added to the brine
container [98] by opening cap [26], no salt can enter into ports
[29] and [30] as the apertures are located at the side of these
elevated ports [29] and [30]. Secondly, when opening valve [31],
only the electrolyte is drained and the brine reservoir [98]
remains filled with granular salt that is collected at the bottom
of the brine reservoir [98] on top of end piece [26]. End piece
[26] has a third port [32] on the bottom of end piece [26] whereas
through a fitting [17] a tube can be connected for the inlet of
electrolyte from the pump [23]. Port [32] has been constructed in
such a way that the aperture of port [31] is located under the
brine fill line. This feature is important for two reasons.
Firstly, when granular salt is added to the brine container [98] by
opening cap [27], no salt can enter into port [31] as the inlet is
located at the side of the port [31]. Secondly, the electrolyte
from the pump is circulated through a brine layer that saturates
the electrolyte. The electrolyte is circulated through pump [23]
which is preferably a peristaltic pump with a variable pump-speed
and which has two fittings [17] to connect a tube from the brine
reservoir [98] to the pump [23] and from the pump [23] to the cell
assembly [100]. The brine concentration can be adjusted by adding
granular salt and softened water into the brine reservoir [98]. The
electrolyte is preferably made by adding granular sodium chloride
into the brine reservoir [98] by opening cap [27]. Besides granular
sodium chloride, granular potassium chloride can be used. The
electrolyte is preferably a saturated aqueous brine solution.
Saturation of the electrolyte is ensured by circulating the
electrolyte through the brine reservoir [98] that is filled with a
certain minimum amount of brine. The electrolyte is circulated from
the bottom of the brine reservoir [98] through a layer of salt that
is at the bottom of the brine reservoir [98].
[0067] This three chamber cylindrical electrolysis cell can be used
with different flow patterns allowing changing the volume of the
cleaning and sanitizing solution, as well the pH and free available
chlorine content. A typical flow pattern permits approximately 30
to 70% of the softened water to pass the anode chamber and
approximately 70 to 30% of the softened water to pass the cathode
chamber. The volume of softened water that passes the anode chamber
or cathode chamber can be restricted by closing a valve which is
mounted in the outlet tube of the anode chamber and the volume of
softened water that passes the cathode chamber can be restricted by
closing a valve that is mounted in the outlet tube of the cathode
chamber. An alternative flow pattern is a flow pattern whereas 100%
of the softened water is passed through either the cathode chamber
or anode chamber. Approximately 70 to 100% of the electrolyzed
solution that either exits the cathode chamber or anode chamber is
re-directed to the inlet of either the anode chamber or the cathode
chamber whereas 0 to 30% of the electrolyzed liquid is collected in
a Sodium Hydroxide storage container or drained as useful
by-product. This alternative flow pattern whereas 70 to 100% of the
electrolyzed solution is collected in a Hypochlorous Acid storage
container is preferred when there is no or little usage of the
by-product and whereas the volume of the main-product is maximized.
A preferred alternative flow pattern is to pass softened water
first through the cathode chamber, wherein the outlet tube is a tee
mounted to allow approximately 20% of the diluted sodium hydroxide
to flow to a storage tank and where approximately 80% of the
diluted sodium hydroxide is re-entered in the anode chamber. The
result of this preferred alternative flow pattern is that
approximately 80% of the softened water has undergone cathodic
electrolysis followed by anodic electrolysis to generate a neutral
pH sanitizing solution. Re-entering more diluted Sodium Hydroxide
into the anode chamber will increase the pH of the diluted
Hypochlorous Acid and re-entering less diluted Sodium Hydroxide
will reduce the pH of the diluted Hypochlorous Acid. The volume of
the diluted Sodium Hydroxide that enters the anode chamber is
regulated by a valve that is mounted in the outlet tube of the
cathode chamber between the tee and the Sodium Hydroxide storage
container.
[0068] One skilled in the art will readily appreciate that the
present invention is well adapted to carry out the objectives and
obtain the ends and advantages mentioned, as well as those inherent
therein. The embodiments, methods, procedures and techniques
described herein are presently representative of the preferred
embodiments, are intended to be exemplary and are not intended as
limitations on the scope. Changes therein and other uses will occur
to those skilled in the art which are encompassed within the spirit
of the invention and are defined by the scope of the appended
claims. Although the invention has been described in connection
with specific preferred embodiments, it should be understood that
the invention as claimed should not be unduly limited to such
specific embodiments. Indeed, various modifications of the
described modes for carrying out the invention which are obvious to
those skilled in the art are intended to be within the scope of the
following claims.
* * * * *