U.S. patent application number 13/987793 was filed with the patent office on 2015-03-05 for chlorine dioxide generator for the efficient generation of chlorine dioxide in dilute solutions.
This patent application is currently assigned to Truox, Inc.. The applicant listed for this patent is Roy W. Martin. Invention is credited to Roy W. Martin.
Application Number | 20150060370 13/987793 |
Document ID | / |
Family ID | 52581667 |
Filed Date | 2015-03-05 |
United States Patent
Application |
20150060370 |
Kind Code |
A1 |
Martin; Roy W. |
March 5, 2015 |
Chlorine dioxide generator for the efficient generation of chlorine
dioxide in dilute solutions
Abstract
Disclosed is an apparatus and method for the safe and efficient
generation of chlorine dioxide. Chlorine dioxide is produced safely
and efficiently by diluting a source of chlorite in water to
produce less than or equal to 5000 ppm measured as ClO.sub.2 while
achieving at least 80 wt%, more preferably 90 wt %, and most
preferred at least 95 wt % conversion of chlorite anion to chlorine
dioxide.
Inventors: |
Martin; Roy W.; (Downers
Grove, IL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Martin; Roy W. |
Downers Grove |
IL |
US |
|
|
Assignee: |
Truox, Inc.
McClellan
CA
|
Family ID: |
52581667 |
Appl. No.: |
13/987793 |
Filed: |
September 3, 2013 |
Current U.S.
Class: |
210/739 ;
210/143; 210/192; 210/754; 210/97 |
Current CPC
Class: |
C02F 2103/023 20130101;
C02F 2209/06 20130101; C09K 8/665 20130101; C02F 2209/29 20130101;
C02F 2103/365 20130101; C02F 2209/003 20130101; C02F 1/76 20130101;
A01N 59/00 20130101; C02F 1/68 20130101; C02F 2209/40 20130101;
C02F 2103/10 20130101; C02F 2209/04 20130101; C09K 8/605
20130101 |
Class at
Publication: |
210/739 ;
210/192; 210/97; 210/143; 210/754 |
International
Class: |
C02F 1/76 20060101
C02F001/76 |
Claims
1) An apparatus for the safe and efficient generation of chlorine
dioxide comprising: a control panel that controls chemical feed
systems, chemical feed systems in fluid contact with chemicals for
the generation of chlorine dioxide and an injection manifold,
chemicals for the generation of chlorine dioxide comprising a
source of chlorite and a source of acidified chlorine, a reaction
chamber; and wherein a source of motive water passing through the
injection manifold is treated by the chemical feed systems with a
source of chlorite and a source of acidified chlorine, and the
motive water treated with a source of chlorite and a source of
acidified chlorine flows through the reaction chamber generating a
dilute aqueous solution of chlorine dioxide.
2) The apparatus according to claim 1, further comprising: a flow
sensor for detecting the motive water; the flow sensor being in
signal contact with the control panel; and wherein the control
panel actuates the chemical feed systems only when motive water is
confirmed.
3) The apparatus according to claim 1, wherein the efficient
generation of chlorine dioxide comprises converting the source of
chlorite to chlorine dioxide with at least 80 wt % conversion of
chlorite anion to chlorine dioxide.
4) The apparatus according to claim 1, wherein the efficient
generation of chlorine dioxide comprises converting the source of
chlorite to chlorine dioxide with at least 90 wt % conversion of
chlorite anion to chlorine dioxide.
5) The apparatus according to claim 1, wherein the dilute aqueous
solution of chlorine dioxide comprises less than or equal to 5000
ppm measured as ClO.sub.2.
6) The apparatus according to claim 1, wherein the chemical feed
systems are slaved together providing proportional variability in
chemical feed rates and in the production rate of chlorine
dioxide.
7) The apparatus according to claim 1, wherein the control panel
automatically varies the chemical feed-rate of the chemical feed
systems using feed-back and/or feed-forward control.
8) The apparatus according to claim 7, wherein the feed-back
control comprises oxidation reduction potential.
9) A method for safe and efficient generation of chlorine dioxide
for the treatment of water systems according to claim 1.
10) A method according to claim 9, wherein the water system
comprises oil and gas hydraulic fracking water.
11) A method according to claim 9, wherein the water system
comprises oil and gas down-hole water.
12) A method according to claim 9, wherein the water system
comprises oil and gas produced water.
13) A method according to claim 9, wherein the water system
comprises hydraulic fracking flow-back water.
14) A method according to claim 9, wherein the water system
comprises cooling water.
15) A method according to claim 9, wherein the water system
comprises food intervention.
16) A method according to claim 9, wherein the water system
comprises waste-water.
Description
RELATED APPLICATIONS
[0001] This Utility Application is a continuation of Provisional
Application No. 61/743,436 filed on Sep. 04, 2012.
BRIEF DESCRIPTION
[0002] Chlorine dioxide generators come in a variety of
configurations and use a range of generating techniques. Generators
that use chlorite, hypochlorite, and acid often comprise an eductor
to form a vacuum to extract a highly concentrated stream of
chlorine dioxide gas and dilute it with water to produce a chlorine
dioxide solution.
[0003] These techniques have the potential to cause explosion
and/or significant harm to personnel due to contact with highly
concentrated chlorine dioxide in the event of a malfunction. The
invention provides a system and method for producing a dilute
chlorine dioxide solution with a concentration ranging from 250 ppm
to 5000 ppm as chlorine dioxide without the need for combining
concentrated streams of chemical reagents and producing potentially
dangerous concentrations of chlorine dioxide gas.
[0004] The invention provides for the safe and efficient generation
of chlorine dioxide with at least 80 wt %, more preferably at least
90 wt %, and most preferably at least 95 wt % conversion of
chlorite anion to chlorine dioxide without the need of forming
concentrated streams of chlorine dioxide prior to dilution with
water.
DEFINITIONS
[0005] As used herein, "safe and efficient generation of chlorine
dioxide" describes the inventions ability to produce chlorine
dioxide with high conversion of chlorite anion to chlorine dioxide
without producing a process stream of chlorine dioxide that has a
concentration of chlorine dioxide gas that is potentially
explosive. The term "safe" refers to the inventions inherent safe
generation of chlorine dioxide achieved by diluting a source of
chlorite in water to achieve a concentration of chlorite anion
necessary to provide less than or equal to 5000 ppm chlorine
dioxide. By diluting the source of chlorite before generating
chlorine dioxide, at no time is the concentration of chlorine
dioxide at explosive levels. The term "efficient" describes the
efficient generation of chlorine dioxide resulting from the
conversion of chlorite anion (as ClO.sub.2) to chlorine dioxide
(ClO.sub.2) of at least 80 wt %, more preferably 90 wt %, and most
preferably 95 wt % conversion of chlorite anion to chlorine
dioxide. The wt % (weight percent) conversion of chlorite anion to
chlorine dioxide can be determined by dividing the parts per
million of chlorine dioxide by the parts per million of chlorite
anion multiplied by 100. The equation is exemplified by: [ClO.sub.2
(ppm)/ClO.sub.2.sup.- (ppm)].times.100=wt % conversion of chlorite
anion to chlorine dioxide.
[0006] As used herein, "dilute aqueous solution of chlorine
dioxide" describes the effluent aqueous solution discharged from
the reaction chamber having a chlorine dioxide concentration of
less than or equal to 5000 ppm measured as ClO.sub.2.
[0007] As used herein, "flow sensor" describes a device that can
detect a liquid flowing through a pipe. The flow sensor can
measure, but is not required to measure the flow rate. The flow
sensor detects motive water in the pipe. One non-limiting example
of a flow sensor is Rotorflow.RTM. Flow Sensors available by
Gems.TM. Sensors and Controls.
[0008] As used herein, "control panel" describes a system that is
used to control at least, but is not limited to, chemical feed
systems. Non-limiting examples of how the control panel can be used
to control chemical feed systems include: actuating chemical feed;
varying the rate of chemical feed; energizing an electronic device
such as a chemical feed pump, solenoid valve, modulating control
valve; stopping chemical feed; and/or initiating a flushing cycle
that removes residual chemicals from the chemical feed system by
either rinsing with water and/or neutralizing chemicals exemplified
by sodium sulfite. The control panel comprises at least relays that
may function as a switch or as a contactor. The control panel can
also comprise microprocessors, programmable logic controllers, and
timers and/or receive input from externally sourced
microprocessors, programmable logic controllers, timers, and
sensors. The control panel can be used to receive and process
information from external sensors for determining ORP,
amperometric, flow-rate measurement, temperature, pH and the like
to optimize the feed-rate of the chemical feed systems and optimize
the feed rate of chlorine dioxide.
[0009] As used herein, "energize" and "energizing" and its
variations describes the activation of an electrical device by
closing a circuit that delivers an electrical current to the
electrical device so that the electrical device performs a desired
function. For example, a flow sensor detects motive water followed
by the control panel energizing the chemical feed systems. In
contrast, when motive water is no longer confirmed by the flow
sensor, the control panel stops the chemical feed systems.
[0010] As used herein, "actuated" and "actuating" and its
variations is an action initiated by the control panel to cause
something to happen such as initiating chemical feed, stopping
chemical feed, initiating a flushing cycle and the like.
[0011] As used herein, "flushing cycle" describes a process of
rinsing at least the injection manifold and reaction chamber with
water or a neutralizing solution that neutralizes chlorine dioxide,
and acidified chlorine and/or their respective chemical sources
exemplified by sodium chlorite, sodium hypochlorite, and
hydrochloric acid. One example of a neutralizing solution is a
solution of sodium sulfite.
[0012] As used herein, "signal contact" describes the ability of an
electronic device exemplified by a flow sensor to communicate with
a control panel. The methods of communication may comprise a signal
transmitted by electromagnetic means &/or by hard wiring.
Electromagnetic means is exemplified by the non-limiting example
radio transmissions, whereas hard wiring in a physical connection
between the electronic device and the control panel by wire.
[0013] As used herein, "electrical contact" describes the hard wire
connection. One non-limiting example is a wire connection between
the control panel and the chemicals feed systems. The electrical
contact can either provide a signal to energize the chemical feed
system or provide the electrical current to directly energize the
chemical feed system.
[0014] As used herein, the term "efficient" describes the
conversion of chlorite anion (as ClO.sub.2) to chlorine dioxide
(ClO.sub.2) of at least 80 wt %, more preferably 90 wt %, and most
preferably 95 wt % conversion of chlorite anion to chlorine
dioxide. The wt % conversion of chlorite anion to chlorine dioxide
can be determined by dividing the parts per million of chlorine
dioxide by the parts per million of chlorite anion multiplied by
100. The equation is exemplified by: [ClO.sub.2 (ppm)/ClO.sub.2
.sup.- (ppm)].times.100=wt % conversion of chlorite anion to
chlorine dioxide.
[0015] As used herein, "fluid contact" describes intimate contact
between conduits capable of transporting liquid between the
different conduits.
[0016] As used herein, "chemical feed systems" describe any
convenient device that is fluid contact with both the chemicals for
the generation of chlorine dioxide and the injection manifold. The
chemical feed systems can be controlled to deliver the desired
amount of reagent to generate the chlorine dioxide. Non-limiting
examples of chemical feed systems include: chemical metering pumps,
educators, modulating control valves and the like.
[0017] As used herein, "chemicals for the generation of chlorine
dioxide" describes chemicals (reagents) for producing an aqueous
solution of acidified chlorine and chlorite anions used to generate
a dilute aqueous solution of chlorine dioxide.
[0018] As used herein, "source of acidified chlorine" describes
reagents needed to produce an aqueous solution of acidified
chlorine comprising chlorine gas (Cl.sub.2) and/or hypochlorous
acid (HOCl). Non-limiting examples of sources of acidified chlorine
may comprise a two reagent treatment comprising hydrochloric acid
and sodium hypochlorite injected separately into the injection
manifold having a source of motive water to form acidified chlorine
in-situ, a mixture of a source of chlorine and an acid source
injected together into the injection manifold, or a source of
chlorine comprising gaseous chlorine that hydrolyzes in the source
of motive water to form hydrochloric acid and hypochlorous
acid.
[0019] As used herein, "injection manifold" describes a manifold
with at least two and preferable at least three inlet ports to
inject a source of chlorite into a source of motive water
separately from the other reagents for the generation of acidified
chlorine used to generate chlorine dioxide. One non-limiting
example of an injection manifold with two inlet ports injects a
source of chlorite into one inlet port and a source of acidified
chlorine into the other inlet port. One non-limiting example of a
three inlet port manifold injects a source of chlorite, source of
chlorine, and an acid source separately through the different inlet
ports, wherein the source of chlorine and acid source produce
acidified chlorine in-situ.
[0020] As used herein, "reaction chamber" describes a chamber
wherein the aqueous solution comprising water, a source of
chlorite, and acidified chlorine react to produce a dilute aqueous
solution of chlorine dioxide. Non-limiting examples of reaction
chambers include: static mixer, a chamber to increase contact time,
or a length of pipe or hose that increases the contact time to
provide at least 80 wt % conversion, more preferably at least 90 wt
% conversion, and most preferably 95 wt % conversion of chlorite
anion to chlorine dioxide. Non-limiting examples of a reaction
chamber include: a static mixer, a chamber providing increased
volume that increases reactants contact time, and/or a length of
pipe or hose that increase the reactants contact time. The reaction
chamber improves the efficiency by improving the kinetics through
either increasing mixing (e.g. static mixer) and/or the reaction
time to allow the reactions to approach completion (increased
volume).
[0021] As used herein, "source of chlorite" describes a compound
that releases chlorite anions having the general formula
ClO.sub.2.sup.- when dissolved in water. Non-limiting examples of a
source of chlorite include: sodium chlorite, potassium chlorite,
and calcium chlorite.
[0022] As used herein, "chlorite anion" describes the precursor
having the general formula ClO.sub.2.sup.- that is converted into
chlorine dioxide ClO.sub.2 when reacted with acidified
chlorine.
[0023] As used herein, "source of chlorine" is any convenient
source of chlorine that releases chlorine gas and/or hypochlorous
acid when dissolved in an acidified aqueous solution. Non-limiting
examples include: gaseous chlorine, sodium hypochlorite, lithium
hypochlorite, calcium hypochlorite, dichloroisocyanuric acid,
trichloroisocyanuric acid, dichlorodimethyl hydantoin and the
like.
[0024] As used herein, "acid source" describes any convenient
source of a hydrogen ions (H.sup.+) that reduce the pH when
dissolved in water. An acid source can comprise mineral acids
and/or organic acids. Non-limiting examples include: hydrochloric
acid, phosphoric acid, sulfuric acid, citric acid, tartaric acid,
fumaric acid and the like.
[0025] As used herein, "chemical feed systems are slaved together"
describes the ability to control the chemical feed-rate in such as
way so that altering the output of one chemical (exemplified by the
source of chlorite) automatically and proportionally alters the
feed-rate of the other chemicals used to generate chlorine dioxide
(e.g. acidified chlorine). This proportional slaving of the
chemicals feed systems allows for consistent efficiency in the
conversion of chlorite anion to chlorine dioxide while providing
variability in the production rate of chlorine dioxide. The
production rate of chlorine dioxide can be automatically adjusted
by the control panel using on feed-back and/or feed-forward
control.
[0026] As used herein, the singular forms "a," "an," and "the"
include plural referents unless the content clearly dictates
otherwise. Thus, for example, reference to a composition containing
"a compound" includes a mixture of two or more compounds. As used
in this specification and the appended claims, the term "or" is
generally employed in its sense including "and/or" unless the
content clearly dictates otherwise.
DESCRIPTION OF FIGURES
[0027] FIG. 1--Flow sensor (501) is in position to detect a source
of motive water being supplied to the injection manifold and in
signal contact with control panel (502). Control panel (502) is in
electrical contact with the chemical feed systems (101).
[0028] Chemical feed systems (101) are in fluid contact with the
chemical (reagents) for the generation of chlorine edioxide
(non-limiting examples NaClO.sub.2, NaOCl, and HCl) and the
injection manifold (201). The injection manifold (201) is in fluid
contact with the reaction chamber (301). The dilute aqueous
solution of chlorine dioxide from the reaction chamber (301) is
sent to the application.
DETAILED DESCRIPTION
[0029] The invention is an apparatus and method for the safe and
efficient generation of chlorine dioxide using chemicals (reagents)
without producing a concentrate of chlorine dioxide. The invention
comprises a plurality of chemical feed systems in fluid contact
with an injection manifold flooded with water by a source of motive
(flowing) water. The plurality of chemical feeds deliver chemicals
for the generation of chlorine dioxide (reagents) comprising a
source of acidified chlorine and a source of chlorite to produce a
dilute aqueous solution of chlorine dioxide. The motive water,
acidified chlorine, and chlorite anion flow through a reaction
chamber and convert at least 80 wt %, more preferably 90 wt %, and
most preferably 95 wt % of the chlorite anion to chlorine dioxide
before being applied to the application.
[0030] In one preferred method the control panel actuates the
chemical feed systems only when motive (flowing) water is confirmed
using a flow sensor and a sufficient period of time is allowed to
lapse to ensure at least the injection manifold is flooded with
motive water before chemical feed is actuated.
[0031] In another preferred embodiment, the control panel varies
the feed-rate of the chemical feed systems and subsequent
production rate of chlorine dioxide based on input from external
sensors in fluid contact with the water system. The sensor(s)
monitor parameters exemplified by the non-limiting examples ORP,
chlorine dioxide concentration, and/or flow-rate. The control panel
automatically varies the chemical feed-rate of the chemical feed
systems using feed-back and/or feed-forward control.
[0032] In another preferred embodiment, chemical feed systems are
slaved together providing proportional variability in chemical feed
rates resulting in consistent efficiency in the conversion of
chlorite anions to chlorine dioxide while providing variability in
the production rate of chlorine dioxide.
[0033] The invention allows for the safe and efficient generation
of dilute aqueous solution of chlorine dioxide without the need to
combine concentrated reagents that generate potentially dangerous
concentrations of chlorine dioxide exemplified by U.S. Pat. No.
6,855,294 and other prior art. Combining concentrated solutions of
acidified chlorine and liquid chlorite rapidly generates
concentrations of chlorine dioxide that can exceed the explosive
concentration threshold of chlorine dioxide. Any interruption in
water flow across the educator can lead to catastrophic events
include injury or death.
[0034] The invention provides for a chlorine dioxide generating
system that dilutes the source of chlorite to achieve a chlorite
anion concentration necessary to produce a dilute aqueous solution
of chlorine dioxide of preferably less than or equal to 5000 ppm
measured as ClO.sub.2. Using this method, the concentration of
chlorine dioxide is sustained well below the explosive threshold of
chlorine dioxide, while achieving the efficiency of generators that
react concentrated solutions of reactants.
[0035] The chemical feed systems are controlled by a control panel.
The control panel can adjust the chlorine dioxide production rate
based on feed-back and/or feed-forward control. For example,
oxidation reduction potential (ORP) and/or amperometric sensors can
be used to monitor the water being treated with chlorine dioxide.
The feed-back from these sensors can be used to automatically
adjust the amount of chlorine dioxide being produced by altering
the feed-rate of the chemicals used to generate chlorine dioxide.
An example of feed-forward is a device that measures flow-rate and
provides data to the control panel so that the feed-rate of
chlorine dioxide is variable based on flow-rate. Feed-back and
feed-forward control can be combined to further optimize chlorine
dioxide product rate and feed-rate.
[0036] Sensors can also be used to monitor and subsequent allow the
control panel to vary the feed-rate of chemicals used to optimize
the production of chlorine dioxide. For example, pH monitoring of
the chlorine dioxide solution can be used to optimize the feed-rate
of an acid source used to produce the acidified chlorine. Other
sensors can be used to monitor useful parameters. Non-limiting
examples of sensors include: oxidation reduction potential (ORP),
amperometric, reagent based automatic titrator, pH, conductivity,
temperature, and ion specific probes.
[0037] Feed-back control can be used to optimize the production
rate and feed-rate of chlorine dioxide. Oxidation reduction
potential (ORP) is one non-limiting example of a control parameter
that can be used as a feed-back control to optimize the feed-rate
of chlorine dioxide. As oxidant demand and/or flow-rate change, the
ORP controller can provide feed-back that automatically varies the
production rate and feed-rate of chlorine dioxide in order to
sustain the desired millivolt potential. Depending on the
application, proportional, proportional integral, proportional
integral differential, or time based proportional control may be
used to optimize the generation and feed-rate of chlorine
dioxide.
[0038] The invention provides a method for safe and efficient
generation of chlorine dioxide for the treatment of water systems.
Non-limiting examples of water systems include: oil and gas
hydraulic fracking water, oil and gas down-hole water, oil and gas
produced water, hydraulic fracking flow-back water, cooling water,
food intervention, and waste-water.
[0039] Oil and gas hydraulic fracking water (frac water) is water
used to create hydraulic fracturing in a rock layer, as a result of
the action of a pressurized fluid. The fracturing of the rock layer
allows trapped oil and gas to be recovered. Frac water must be
treated to kill waterbome bacteria to prevent contamination of
[0040] Oil and gas down-hole treatment comprises using water
treated with chlorine dioxide often combined with other chemicals
such as surfactants, chelants, acids and the like to increase the
oil and/or gas production of the well. Wells can become sour from
anaerobic bacteria producing hydrogen sulfide which sours the oil
and gas. Bacterial bio-films, iron sulfide deposits, and corrosion
byproducts can foul the well and reduce oil and gas production.
Down-hole treatment with at least chlorine dioxide can increase
productivity by removing the foulants.
[0041] Flow-back water and produced water is water that is returned
to the surface from gas and oil wells. Flow-back water is treated
frac water that contains frac chemicals such as surfactants,
dissolved solids, suspended solids and often oil. Produced water
occurs after the frac process that contains the oil and/or gas
resulting from the production of the well. Both the frac water and
produced water can be treated with chlorine dioxide to induce
coagulation of organics, removal of oxidant demand such as hydrogen
sulfide, and disinfect the water for re-use in frac operations.
[0042] Cooling water can be once-through or circulated for the use
of cooling process equipment such as heat exchangers. Circulated
cooling water is often passes across cooling towers, or spray ponds
to induce evaporation to lose heat of vaporization.
[0043] Chlorine dioxide is an effective biocide for treating water
used in "food intervention" for the treatment of a food product or
food, and/or food processing systems to killing one or more of the
food-borne pathogenic bacteria associated with a food product, such
as Salmonella typhimurium, Salmonella javiana, Campylobacter
jejuni, Listeria monocytogenes, Escherichia coli O157:H7, and the
like.
[0044] A "food product" or "food" refers to any food or beverage
item that may be consumed by humans or mammals. Some non-limiting
examples of a "food product" or "food" include the following: meat
products including ready-to-eat ("RTE") meat and poultry products,
processed meat and poultry products, cooked meat and poultry
products, and raw meat and poultry products including beef, pork,
and poultry products; fish products including cooked and raw fish,
shrimp, and shellfish; produce including whole or cut fruits and
vegetables and cooked or raw fruits and vegetables; eggs, and
egg-based products.
[0045] The "food processing systems" refers to the surfaces of
equipment and surroundings used to process food. Food processing
systems includes the equipment and building structures used to
process, produce, store, wash, move, sanitize, cut, and package
consumable food items.
[0046] Waste-water can be treated with chlorine dioxide to oxidize
odors exemplified by the non-limiting examples hydrogen sulfide and
mercaptans, kill microbiological organisms, oxidize organics, and
induce coagulation. Waste-water is any source of water that is
discarded and is not deemed suitable for discharge to NPDES
regulated waterways or for use by mammals for washing or
consumption.
* * * * *