1. Field of the Invention
This invention relates generally to chlorine dioxide generators and in particular to chlorine dioxide generators having a primary vessel and replaceable, slide-in or screw-in reaction vessel.
2. Description of Related Art
Chlorine dioxide generators are primarily used in two fields, such as pulp and paper processing and drinking water purification. These generators are large, producing many pounds of chlorine dioxide gas daily. Since chlorine dioxide gas can become unstable in higher concentrations, which may accumulate in large-scale generation, these generators require skilled operators and numerous safely devices. In addition to the vast quantities of gas produced, the handling of precursor chemicals such as chlorine gas also becomes a safety concern. Though these large-scale generators could possibly be scaled down in size, they are still quite expensive and would require the same skills to operate.
There are also small-scale generators that use tea bag-like membrane technologies, which produce chlorine dioxide very slowly, on the order of many hours. These small-scale generators are currently being used or tested for various fields of use on a small scale. Additionally, the bags produce small amounts per bag, generally on the order of several grams or less of gas per bag.
The following prior art patents disclose gas generating apparatus and chlorine dioxide generators.
U.S. Pat. No. 5,004,586, issued Apr. 2, 1991 to Minoru Hayashi et al. and assigned to Nippon Koki Co., Ltd. discloses a gas generating apparatus for inflating an air bag protection against collision, life bag, rubber boat, escape chute, etc., comprising a housing and a combustion chamber. A threaded portion inside the housing is screwed into a cylinder which forms the combustion chamber with a multiplicity of combustion gas orifices around its outer circumferential wall. A gas generating agent is stored inside the combustion chamber nozzle is provided for ejecting high-pressure gas flowing from the combustion chamber into a mixing chamber. A gas generating agent in the form of either granules or pellets is stored in the combustion chamber. However, although this is a gas generating apparatus; it is not suitable for safely generating a carbide dioxide gas.
U.S. Pat. No. 6,071,483, issued Jun. 6, 2000 to Mauro Pastore discloses a reactor vessel and process for preparing a controlled-dosage chlorine dioxide solution comprising a hollow body having a first chamber and a second chamber which are mutually connected by a cylindrical duct which lies horizontally between the upper portion of chambers near removable plugs of the vessel. An aqueous solution or a buffered acid solution is introduced into a chamber. A water-soluble compound, capable of releasing chlorine dioxide and a water-soluble proton donor are introduced into a chamber. The vessel is tilted so as to introduce in one chamber a required amount of the aqueous solution, and then the vessel is returned to the uprighted position. A chemical reaction occurs inside the chamber which releases chlorine dioxide vapors which diffuse through a duct into the aqueous solution contained in another chamber. The vessel is turned upside down so as to fully mix the product in one chamber with the aqueous solution in another chamber. However, a closed loop system of a pressurized canister forcing a chlorine dioxide/air mixture into a primary solution vessel is not disclosed.
U.S. Pat. No. 6,238,643 issued May 29, 2001 to Appadurai Thangaraj et al. and assigned to Engelhard Corporation of Iselin, N.J. discloses a method of producing an aqueous solution of chlorine dioxide from the reaction of a metal chlorite and an acid forming component which do not react to produce chlorine dioxide in substantial absence of water. The reactants are separated from liquid water by a membrane which allows the controlled passage of liquid water and/or water vapor into contact with the reactants. However, this method of generating chlorine dioxide is very slow and a closed loop system of a pressurized canister forcing a chlorine dioxide/air mixture into a primary solution vessel is not disclosed.
Therefore, it is desirable to have a small-scale chlorine dioxide generator with safety features for generating a chlorine dioxide gas in a canister and forcing a chlorine dioxide/air mixture into a primary solution vessel in a reasonable amount of time.
Accordingly, it is therefore an object of this invention to provide a self-priming chlorine dioxide generator comprising a primary vessel and a replaceable canister connected to the primary vessel.
It is another object of this invention to provide means for locking the canister within the bottom end of the primary vessel until a reaction goes to completion or an expert removes the canister.
It is a further object of this invention to provide a controller to monitor sensors which sense the canister is fully engaged, fluid level, sealing of the primary vessel and canister, and temperature.
It is another object of this invention to provide a closed loop system for generating chlorine dioxide solution using a combination vacuum and pressure pump attached to a vessel air space cap.
These and other objects are further accomplished by a chlorine dioxide generator comprising a primary vessel having a solution chamber, means for supplying priming water to a canister attached to the primary vessel, the canister having predetermined chemicals for producing chlorine dioxide gas, the canister sealably engages to the primary vessel, and means for providing a path for the priming water and air to pass through the primary vessel to the canister when the canister is engaged to the primary vessel. The generator comprises means for locking the canister within the primary vessel when the canister is fully engaged to the primary vessel. The primary vessel comprises a receptacle for directly engaging with the canister. The receptacle comprises a gas flow lid having a feed tube inserted in the lid, the lid being opened when the canister is fully engaged with the receptacle. The canister comprises a grommet in the engaging end of the canister for sealably engaging with the feed tube of the gas flow lid. The vessel receptacle comprises a membrane for allowing a gas generated in the canister to pass into the solution chamber of the primary vessel. The vessel comprises means for sensing when the canister is fully engaged to the primary vessel prior to start of a chemical reaction sequence. The canister comprises a relief valve to prevent an overpressure of the generated chlorine dioxide gas from occurring in the canister. The primary vessel comprises means for detecting a predetermined gas concentration in the solution chamber. The pump provides the air to the primary vessel. The controller is connected to the pump, the controller having a control panel for controlling and monitoring the operation of the chlorine dioxide generator. The canister comprises at least two chambers for storing the predetermined chemicals.
The objects are further accomplished by a chlorine dioxide generator comprising a primary vessel having a priming chamber and a solution chamber, the primary vessel comprises a first inlet for receiving air for delivery to the priming chamber and a second inlet for receiving water for delivery to the priming chamber and the solution chamber, a canister having predetermined chemicals for producing chlorine dioxide gas, the canister sealably engages to the primary vessel; and means for providing a path for the water and the air to pass from the priming chamber to the canister when the canister is engaged to the primary vessel. The generator comprises means for locking the canister within the primary vessel when the canister is fully engaged to the primary vessel. The chemicals react with the water provided to the canister from the priming chamber to produce the chlorine dioxide gas. The primary vessel comprises a receptacle for directly engaging with the canister. The receptacle comprises a gas flow lid having a feed tube inserted in the lid, the lid being opened when the canister is fully engaged with the receptacle. The canister comprises a grommet in the engaging end of the canister for sealably engaging with the feed tube of the gas flow lid. The vessel receptacle comprises a membrane for allowing a gas generated in the canister to pass into the solution chamber of the primary vessel. The primary vessel comprises means for sensing when the canister is fully engaged prior to start of a chemical reaction sequence. The canister comprises a relief valve to prevent an overpressure of the generated chlorine dioxide gas from occurring in the canister. The primary vessel comprises means for detecting a predetermined gas concentration in the solution chamber. The pump provides the air to the primary vessel. The controller is connected to the pump, the controller having a control panel for controlling and monitoring the operation of the chlorine dioxide generator.
The objects are further accomplished by a primary vessel for a chlorine dioxide generator comprising a solution chamber, a vessel plate attached to the top of the solution chamber, a priming chamber located within an upper portion of the solution chamber having an opening extending through the vessel plate, a vessel receptacle attached to a bottom of the solution chamber having a gas membrane located at the interface between the vessel receptacle and the solution chamber, the vessel receptacle comprises means for receiving a source of chlorine dioxide gas, and means for providing a path for liquid to flow from the priming chamber to a valve in the vessel receptacle. The vessel plate comprises a dome having a valve for receiving a first air supply tube, and a second air supply tube connects to the priming chamber for supplying air. The top vessel plate comprises an anti-siphon block having an input from the priming chamber and an output connected to the valve on the vessel receptacle. The gas membrane located at the interface between the vessel receptacle and the solution chamber allows for the passage of chlorine dioxide gas into the solution chamber. The primary vessel comprises a gas concentration detector positioned within the solution chamber. The vessel receptacle comprises a gas flow lid which opens when the chlorine dioxide gas source is attached to the vessel receptacle. The chlorine dioxide gas source comprises a canister having predetermined chemicals for producing chlorine dioxide gas.
The objects are further accomplished by a method of generating a chlorine dioxide solution comprising the steps of providing a primary vessel having a solution chamber and a canister attached to the solution chamber, providing water to the solution chamber, providing predetermined chemicals in the canister for producing chlorine dioxide gas for delivery to the primary vessel, and providing a path through the primary vessel for priming water and air to pass to the canister for generating the chlorine dioxide gas. The step of providing means for locking the canister within the primary vessel when the canister is fully engaged to the primary vessel. The path for the priming water and the air to pass to the canister comprises the step of the predetermined chemicals reacting with the priming water provided to the canister to produce the chlorine dioxide gas. The step of providing a receptacle having a gas flow lid with a feed tube inserted in the lid, the lid being opened when the canister is fully engaged with the receptacle. The step of providing a receptacle comprises the step of providing a membrane for allowing a gas generated in the canister to pass into the solution chamber of the primary vessel. The step of providing a primary vessel comprises the step of sensing when the canister is fully engaged prior to start of a chemical reaction sequence. The step of connecting a canister comprises the step of providing a relief valve to prevent an overpressure of the generated chlorine dioxide gas from occurring in the canister. The step of providing a primary vessel comprises the step of detecting a predetermined gas concentration in the solution chamber. The method comprises the step of providing a pump to supply the air to the primary vessel. The method comprises the step of providing a controller having a control panel for controlling and monitoring the operation of generating the chlorine dioxide solution.
The objects are further accomplished by a canister for generating chlorine dioxide gas comprising means for attaching the canister to a device for receiving the chlorine dioxide gas, means for storing chemicals within the canister to generate the chlorine dioxide gas, means for providing a path within the canister for air and water to come in contact with the chemicals to generate the chlorine dioxide gas. The attaching means comprises a threaded neck portion for screwing the canister into the device. The attaching means comprises a tube having a first end attached to the canister and a second end attached to the device for receiving the chlorine dioxide gas. The storing means comprises at least two chambers including a first chamber in a base portion of the canister for holding a first chemical and at least a second chamber in the base portion for holding a second chemical. The at least two chambers comprises holes between the first chamber and the at least second chamber, each of the holes being sealed by a water dissolvable film. The means for providing a path for air and water comprises a gas flow valve extending from a top portion of the canister to the chemical storing means. The gas flow valve comprises a grommet positioned on top of the valve for providing a seal when the canister is attached to the device for receiving the chlorine dioxide gas. The gas flow valve comprises a spring for sealing the valve when the canister is not connected to the device to prevent leakage of any chlorine dioxide gas. The canister comprises a relief valve to relieve an excess amount of pressure from within the canister. The canister comprises means for activating an engagement signal when the canister is completely attached to the device for receiving the chlorine dioxide gas.
The objects are further accomplished by a method of generating chlorine dioxide gas in a canister comprising the steps of attaching the canister to a device for receiving the chlorine dioxide gas, storing chemicals within the canister to generate the chlorine dioxide gas, providing a path within the canister for air and water to come in contact with the chemicals to generate the chlorine dioxide gas. The step of attaching the canister to a device for receiving the chlorine dioxide gas comprises the step of providing a threaded neck portion for screwing the canister into the device. The step of attaching the canister to a device comprises the step of providing a tube having a first end attached to the canister and a second end attached to the device for receiving the chlorine dioxide gas. The step of storing chemicals within the canister comprises the steps of providing a first chamber in a base portion of the canister for holding a first chemical, and providing a second chamber in the base portion for holding a second chemical. The steps of providing a first chamber and a second chamber in the base portion of the canister for storing chemicals comprises the steps of providing at least one hole between the first chamber and the second chamber, and covering the at least one hole with a water dissolvable film. The step of providing a path for air and water to contact the chemicals comprises the step of providing a gas flow valve extending from an upper portion of the canister to the stored chemical.
Additional objects, features and advantages of the invention will become apparent to those skilled in the art upon consideration of the following detailed description of the preferred embodiments exemplifying the best mode of carrying out the invention as presently perceived.
The appended claims particularly point out and distinctly claim the subject matter of this invention. The various objects, advantages and novel features of this invention will be more fully apparent from a reading of the following detailed description in conjunction with the accompanying drawings in which like reference numerals refer to like parts, and in which:
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A tube 39b extends from within the vessel air space dome 38 to a side of a priming chamber 12 to provide air to the priming chamber 12 from the pump 14. Another tube 62 connects to the bottom of the priming chamber 12 and extends through the top vessel plate 46 and into the anti-siphon block 47. Another tube 15 extends from the anti-siphon block 47 through the top vessel plate 46 down inside the primary vessel 11 and connects to a valve 68 in the center of a top gas valve plate 78 of the vessel receptacle 23. Extending from the bottom of the priming chamber 12 is an angled bracket 67 for mounting a chlorine dioxide gas concentration detector 26. Two fiber optic cables 64, 65 connect to opposite ends of the chlorine dioxide gas concentration detector 26 and the other ends of the fiber optic cables 64, 65 connect to a sensor 66 attached to and extending above top vessel plate 46.
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The primary vessel 11 comprises the top vessel dome 38 to which the relief valve 30 is connected, and the air input tube 39a extends from a pump 14 and interfaces with a connector on top of the vessel dome 38. The air tube 39a provides air to the top vessel dome 38 and air tube 39b continues the air flow to the priming chamber 12 located in an upper portion of the primary vessel 11 adjacent to the water inlet. An output tube 62 from the priming chamber 12 extends up to the top vessel plate 46 where it is connected to the anti-siphon block 47 and then to the air-primer feed line 15 extends from the anti-siphon block 47 through the primary vessel 11 and connects to connection valve 69 at the vessel receptacle 23. Also connected through the top vessel plate 46 are the ends of fiber optic cables 64, 65 extending from a gas concentration detector 26 through a feed-through 66 in the top vessel plate 46 and then to amplifiers (known by one of ordinary skill in the art) within the controller 27.
The air-primer feed line 15 extends downward to a connection valve 68 in the center of the vessel receptacle 23 wherein the feed line extension 52 continues through grommet 18 in the neck 42 and down into the canister 17. The feed line extension 52 connects with the canister chamber gas flow valve 36. The pump 14 may be embodied by Model No. BP-202 manufactured by Binaca Products of Temecula, Calif. The air pressure provided from the pump 14 to the canister 17 is typically 5-6 PSI.
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The canister 17 may also be secured within the vessel receptacle 23 by a snap-in connection, and in another configuration, the canister 17 can be located separate from the primary vessel 11 having a tube connection between the top of the canister 17 and the vessel receptacle 23.
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Once the canister 17 is fully engaged, a RUN indicator light 133 on the control panel 60 comes ON indicating the canister 17 is fully engaged. At this point, power is turned off from the solenoid 29 and the solenoid rod 28 enters a canister lock slot 53. At this point an operator cannot remove the canister 17 until a reaction goes to completion or an expert operator removes the canister 17.
The controller 27 is under program control stored in a memory within the PLC of the controller 27. The controller 27 checks several sensors as shown in
Then, the priming chamber 12 is pressurized and the water in the priming chamber 12 is forced through the air-primer feed line 15 to the canister reaction chamber 16. The canister 17 then fills with the predetermined amount of water from the priming vessel 12 followed by a continuous flow of air for approximately 25-30 minutes, which flows through the now dry priming vessel 12 and to the canister reaction chamber 16. The gas 60 bubbles flow out of canister 17, through the recipient solution and accumulate in the upper portion of vessel 11 and in the dome 28. There is a port 31 on the top of the dome 38 which is connected to the vacuum side of the pump 14. This make-up air has CLO2 gas in air which is recirculated through the generator 10 by the pump 14.
This closed loop operation optimizes gas transfer to the recipient solution.
The canister 17 of the chlorine dioxide generator 10 is a triple action, replaceable, screw-in reaction vessel. The triple action includes the following steps of reaction: a) the partial opening of a spring loaded gas flow lid 18 in the gas flow chamber 19 beneath the recipient solution chamber 20 in the primary vessel 11, b) the complete opening of the spring loaded canister gas flow valve 21, and c) the completion of opening of the spring loaded gas flow lid 18, which then triggers the sequence of pump-initiation-gas flow. This is achieved by activating the canister proximity microswitch 22, which closes the contacts to an electrical relay in the controller 27. This sequence starts the reaction sequence to generate the chlorine dioxide gas 50. The triple acting aspect is a safety feature incorporated to insure that the initiation of the reaction of dry chemicals 37a, 37b in the canister 17 does not occur until both the gas flow lid 18 is opened and the canister 17 is fully engaged and sealed into the vessel receptacle 13.
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The dry chemicals 37a, 37b in the canister, cannot be removed once the reaction is initiated until the chemical reaction goes to completion: This is because the canister 17 is self-sealing only upon removal. If the canister 17 was resealed immediately after initiation, the generated gas within the canister 17 could possibly build up too high of a pressure if all other safety devices failed. Since the chlorine dioxide gas 50 may be unstable at very high concentrations, its pressure could possibly burst the canister 17 and release the gas in a high concentration. Therefore, the generator 10 incorporates the locking solenoid 29, which locks the canister 17 just prior to initiation of the chemical reaction and will not release the canister 17 until the chemical reaction has gone to completion. This is achieved by the push-pull solenoid 29 that is normally engaged (without power), thereby inhibiting rotation of the screw-in canister 17 until the push-pull solenoid 29 is energized. The solenoid 29 may be embodied by Model 195202-234, manufactured by LEDEX Products of Vandalia, Ohio.
A vessel relief valve 30 (or optional redundant dual vessel relief valves in parallel) is also incorporated on the top vessel dome 38 of the primary vessel 11. The vessel relief valve 30 allows for the following: venting when power is lost, venting when the recipient solution is being emptied from the vessel 11, and venting if an elevated temperature is sensed by the controller 27 while under power. Elevated temperatures may result in unwanted elevated gas pressure in the air spaces within the vessel 11. This is important because the preferred situation is to have atmospheric pressure above the solution, thereby keeping the optimum amount of chlorine dioxide gas 50 in the solution. The vessel relief valve 30 may be embodied by Model 501200, manufactured by ADVANTEC MFS, INC., of Pleasanton, Calif.
A canister relief valve 32 is incorporated into the top of the canister 17 to prevent an overpressure situation as mentioned earlier. The canister relief valve 32 is designed to relieve pressure from within the canister 17. The size of the vent hole 32 is 1/16 inch in diameter with provisions for an O-ring and PTFE membrane material to cover it.
The chlorine dioxide generator 10 is approximately 40 inches in height. The primary vessel 11 is 9 inches in diameter×22 inches high, comprising type 304 stainless steal ⅛ inch thick. It holds approximately 22 liters or 5 gallons. The canister 17 is approximately 8 inches high and 4 inches in diameter. Two mounting bars 40a, 40b are welded on to the side of the primary vessel 11. The stainless steel is coated with PTFE to avoid oxidation. The housing of the canister 17 is made of CPVC plastic. The O-rings are all rubber and gaskets are made of fluorocarbon rubber. All tubing is PTFE or FEP. All fittings are PVDF plastic. Alternatively, all of the stainless steel components could be made of plastic. Among the preferred materials are PUDF, CPVC and PVC. The geometry of the components could also be sealed larger or smaller to generate more or less gas in solution.
This invention has been disclosed in terms of certain embodiment. It will be apparent that many modifications can be made to the disclosed apparatus without departing from the invention. Therefore, it is the intent of the appended claims to cover all such variations and modifications as come within the true spirit and scope of this invention.
This is a nonprovisional patent application claiming priority of provisional application for patent Application No. 60/627,554, filed Nov. 12, 2004.
Number | Date | Country | |
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60627554 | Nov 2004 | US |