In some cleaning applications, one or more chemicals are reacted to form a cleaning solution when needed. During such cleaning applications, the cleaning process can be delayed or prolonged according to the amount of time needed to generate the cleaning product. Furthermore, depending upon the amount of cleaning solution needed, high demands can be placed on the reaction device or devices, such as ion exchange beds or catalyst containers, to satisfy peak demands. In order to expedite the production of cleaning solution, the reaction devices can tend to be quite large to allow a large amount of reactants or intermediate cleaning products to react in a timely manner. In one particular example, some conventional clean-in-place systems use a cleaning solution that is produced via chemical reaction just prior being used. However, because a clean-in-place system can require a large quantity of cleaning solution, the cleaning process can be significantly delayed waiting for the proper amount of cleaning solution to be produced.
Chlorine dioxide (ClO2) can be used as the cleaning solution in some applications. Chlorine dioxide is known to have bleaching, disinfecting and sterilizing properties. For example, chlorine dioxide is a powerful viricide, bactericide, protocide, and algaecide. Accordingly, chlorine dioxide is used in a variety of large scale industrial applications including municipal water treatment as a bactericide, still water treatment, water hygiene taste and odor control, and zebra mussel infestation control, to name a few. It is used to bleach paper and flour, and it is also particularly useful where microbes and/or organic odorants are sought to be controlled on and around foodstuffs.
Unfortunately, chlorine dioxide is not stable for long periods of time. Specifically, at normal operating pressures and temperatures, chlorine dioxide is a gas and is extremely explosive. For example, chlorine dioxide can be explosive at pressures above about 0.1 atmosphere. Therefore, chlorine dioxide gas is not manufactured and shipped under pressure like other industrial gases. Rather, due to its inherent instability, chlorine dioxide must be produced in situ at the point of use. Conventional methods of on-site manufacture prepare chlorine dioxide by oxidation of chlorites or reduction of chlorates, as needed. These conventional methods generally require expensive generation equipment and a high level of operator skill to avoid generating dangerously high concentrations. Due to these constraints, the use of chlorine dioxide has typically been limited to large commercial applications, such as pulp and paper bleaching, water treatment, and poultry processing, where the consumption of chlorine dioxide is sufficiently large that it can justify the capital and operating costs of expensive equipment and skilled operators for on-site manufacture.
The present invention is directed to a method and apparatus for producing and dispensing a cleaning solution. The cleaning solution of some embodiments is produced by reacting or catalyzing one or more chemicals or reactants within a dispensing apparatus.
In some embodiments, the dispensing apparatus has one or more conduits, chambers, vessels, reservoirs, etc., wherein one or more portions of the dispenser contain a catalyst and/or reactant. As a precursor passes through the dispensing apparatus, it reacts in response to entering the portion containing the catalyst and/or reactant to form a cleaning solution or a precursor cleaning solution. This cleaning solution or precursor cleaning solution can be stored in a tank for dispensing. In some embodiments, one or more portions of the dispensing apparatus are coupled to a mobile platform. For example, the tank can be coupled to a mobile platform to allow the cleaning solution or precursor cleaning solution to be transported to a dispensing location.
In one particular application of the above embodiment, sodium chlorite is used as a precursor and is fed through an ion exchange bed to form chlorous acid or a cleaning solution precursor. The chlorous acid is stored in a tank for later use. When a cleaning solution is desired to be dispensed, the chlorous acid passes through a catalyst, which then produces chlorine dioxide. In some embodiments, the storage tank and catalyst are coupled to a mobile platform.
In another application of the above embodiment, chlorous acid is used as a precursor for a cleaning solution containing chlorine dioxide. Chlorous acid passes through the conduit toward a storage tank. Prior to reaching the storage tank, the chlorous acid is fed though a catalyst, which then produces chlorine dioxide. Immediately thereafter, the chlorine dioxide or chlorine dioxide solution can be introduced into water in a desired concentration (about 0-1500 ppm in some situations) and the chlorine dioxide cleaning solution is stored in the tank for quick dispensing. In some embodiments, one or more of the conduit, storage tank, and catalyst are coupled to a mobile platform.
In some embodiments, the dispensing apparatus has a first portion containing a first reactant, mixture of reactants, or other precursor used to produce the cleaning solution and a second portion containing a second reactant, mixture of reactants, other precursor, or catalyst used to produce the cleaning solution. The first portion of the dispenser is in fluid communication with the second portion. During the dispensing operation, the contents of the first portion contact the contents of the second portion, which causes a chemical reaction to produce the cleaning solution. Substantially immediately thereafter, the cleaning solution is used. In some embodiments, either the first portion or the second portion or both can be coupled to a mobile platform.
In one particular application of the above embodiment, the dispenser can generate chlorine dioxide on demand at end use points, which eliminates the need to generate and store high concentrations of chlorine dioxide. The first portion of the dispenser contains chlorous acid as a precursor to the generation of chlorine dioxide and the second portion of the dispenser contains a catalyst that catalyzes the reaction of chlorous acid to form chlorine dioxide. The chlorous acid is kept separate from the catalyst until chlorine dioxide is called for. Upon demand for chlorine dioxide, the chlorous acid is fed through the catalyst to produce chlorine dioxide. The chlorous acid flows through the catalyst during the dispensing operation.
The dispensers of the present invention can be used for continuous or batch production/dispensing. However, some embodiments have particular utility for batch dispensing. For example, some dispensers are mobile and can be effectively used for batch dispensing. As such, the dispenser can be transported to an end use location, which eliminates the need for installation of expensive equipment at the end use location. The dispenser can be coupled to a base that is mobile. For example, in one embodiment, the base has a plurality of wheels that allow the dispenser to be moved to a desired end use location. The dispenser can include a storage area and a reaction area coupled to the base. If the mobile dispenser is used for chlorine dioxide generation, the storage area can be used to store either a batch of chlorous acid or chlorine dioxide cleaning solution as described in the above embodiments.
In one method of producing and dispensing chlorine dioxide, sodium chlorite is stored in a controlled environment away from the dispensing point of use. The sodium chlorite is fed in a dilute form into an ion exchange resin bed where hydrogen (H+) is exchanged for sodium (Na+) to convert the sodium chlorite to chlorous acid or a relatively stable mixture containing chlorous acid. The chlorous acid is then transported closer to the point of use, where it is contained within a first portion of a dispenser. During a dispensing operation, the mixture containing chlorous acid contacts a catalyst, which causes chlorine dioxide to be produced. The chlorine dioxide is then dispensed in an aqueous solution for use as a cleaning solution.
These and other aspects of the present invention, together with the organization and operation thereof, will become apparent from the following detailed description of the invention when taken in conjunction with the accompanying drawings.
Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limited. The use of “including,” “comprising” or “having” and variations thereof is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. The terms “mounted,” “connected” and “coupled” are used broadly and encompass both direct and indirect mounting, connecting and coupling. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings, and can include electrical connections or couplings, whether direct or indirect.
The apparatus 10 includes a chemical reaction area 14 coupled to a storage area 18. The chemical reaction area 14 has an inlet 20 and an outlet 22. A precursor chemical enters the inlet 20, reacts within the reaction area 14, and then passes through the outlet 22. Depending upon the chemicals involved and/or the type of reaction desired, the chemical reaction area 14 can be a fluid passage or conduit, such as a pipe or other line, or it can be a tank, vessel, chamber, or other container. The reaction area 14 can also contain one or more reactants, catalysts, precursors, or the like. In the embodiment illustrated in
As the precursor chemical is fed through the container 24 of the reaction area 14, a chemical reaction occurs to form a precursor cleaning solution or cleaning solution. In the present example, chlorous acid is fed through the catalyst to form chlorine dioxide, which can be used as a cleaning solution. The specifics of this reaction and other similar reactions are known in the art and therefore will not be discussed herein. United States Published Application No. 2003/0064018, which is hereby incorporated by reference, discusses the chemistry regarding conversion of chlorous acid via a catalyst to chlorine dioxide.
The product of the reaction of this embodiment is then sent to the storage area 18. The storage area 18 can be a fluid passage, conduit, container, or the like. In the illustrated embodiment, the storage area is a tank 26. The tank 26 has a product inlet 28 and a product outlet 30. The product inlet 28 communicates with the reaction area via a conduit 32. The product outlet 30 has a dip tube 36 with an opening positioned near the bottom of the tank 26. The product can exit the tank 26 through the dip tube 36 with the assistance of air pressure.
As illustrated, the tank 26 has a pressurized air inlet 34. The inlet 34 is coupled to a source of pressurized air, where the amount and pressure of the air entering the tank 26 can be regulated many different ways. For example, one or more valves and pressure regulators can be used to control the amount and pressure of the air delivered to the tank. The pressurized air assists with dispensing the product from the tank 26. Specifically, it increases the pressure within the tank 26, which forces the product out of the tank 26 through the dip tube 36. The pressure can control the concentration of chlorine dioxide wherein a higher pressure can result in a higher concentration of chlorine dioxide.
The pressurized air inlet 34 can also be used as an outlet for the tank 26 as well. Once some or all of the product has been dispensed from the tank 26, a substantial quantity of air can remain in the tank 26. As the tank 26 is being refilled with product, one or more valves 38 can be opened to allow the air pressure to escape. As illustrated, a filter 39 back flow preventer 29 can be located adjacent the valve to filter the fluid exiting the tank 26 via outlet 34, which could contain limited amounts of chlorine dioxide. Any chlorine dioxide that is expelled in the aforementioned way can be gathered as a source of purified chlorine dioxide for further use.
Product can be drawn from the tank 26 via a flow controller 40 that is coupled to the outlet 30 of the tank 26. The flow controller 40 can control the amount of product dispensed from the tank 26 in response to an operator's intent. One type of flow controller is a venture, which uses pressure to expel the cleaning solution. However, other flow controllers can be used.
The apparatus 10 also has a product dispensing outlet 42 through which product is dispensed. In some embodiments, this outlet 42 is provided with a quick connect fitting to allow quick connection with a system needing the product. For example, as illustrated in
In one particular operation of the apparatus 10 illustrated in
Like the cleaning solution generating and dispensing apparatus 10 of
The apparatus 110 includes a chemical reaction area 114 coupled to a storage area 118. Unlike the previous embodiment of
The storage area 118 of
Precursor can be drawn from the tank 126 via a flow controller 140 coupled to the outlet 122 of the tank 126. Precursor is delivered to the reaction area 114 prior to dispensing. The flow controller 140 can control the amount of precursor dispensed from the tank 126 in response to an operator's intent. The precursor chemical enters the inlet 120 of the reaction area 114 and reacts within the reaction area 114. The product of the reaction then passes through the outlet 122 of the reaction area 114 to be dispensed. Depending upon the chemicals involved and/or the type of reaction desired, the chemical reaction area 114 can be a passage or conduit, such as a pipe or other line, or it can be a tank, vessel, chamber, or other container. The reaction area 114 contains one or more reactants, catalysts, precursors, or the like. Assuming the illustrated embodiment is used to generate chlorine dioxide, a catalyst for driving chlorous acid to chlorine dioxide is contained within container 124.
Like the previous embodiment of
One particular operation of the apparatus 110 illustrated in
Various alternatives to the certain features and elements of the present invention are described with reference to specific embodiments of the present invention. With the exception of features, elements, and manners of operation that are mutually exclusive of or are inconsistent with each embodiment described above, it should be noted that the alternative features, elements, and manners of operation described with reference to one particular embodiment are applicable to the other embodiments.
Various features of the invention are set forth in the following claims.
This claims priority under 35 U.S.C. §119(e) to U.S. provisional patent application No. 60/654,984 filed on Feb. 22, 2005.
| Number | Date | Country | |
|---|---|---|---|
| 60654984 | Feb 2005 | US |