| PATENT NUMBER | This data is not available for free |
| PATENT GRANT DATE | May 2, 1995 |
| PATENT TITLE |
Regulating water treatment agent dosage based on operational system stresses |
| PATENT ABSTRACT | A target-specie responsive regulation of water treatment agent feed is achieved by the monitoring of a subject target-specie indicator. A target specie in a sample taken from the system is selected as the subject target-specie indicator, or instead an incipient reagent is added to the system sample to form a subject target-specie indicator. Such a formed subject target-specie indicator comprises a combination of the incipient reagent and a target specie. The subject target-specie indicator might then monitored by fluorescence analysis of the sample to determine at least one fluorescence emission value that can be correlated to the in-system concentration of the target specie. In combination with an inert tracer, the system consumption for the target specie can be determined. A responsive adjustment of the in-system concentration of a water treatment agent can be made |
| PATENT INVENTORS | This data is not available for free |
| PATENT ASSIGNEE | This data is not available for free |
| PATENT FILE DATE | February 14, 1994 |
| PATENT CLAIMS |
We claim: 1. A method of regulating the in-system concentration of a water treatment agent in an industrial fluid system comprising: adding an inert tracer to an industrial fluid system, the inert tracer being added in known proportion to a target specie also being added to said industrial fluid system, wherein the system consumption of the target specie is effected by the water treatment agent; drawing a sample of fluid from said industrial fluid system; monitoring the target-specie by analysis of said sample to determine at least one characteristic that can be correlated to an in-system concentration of said target-specie; monitoring said inert tracer by analysis of said sample to determine the in-system concentration of said inert tracer; determining the system consumption of the target specie from the measured in-system concentration of the target specie and the inert tracer; and regulating the in-system concentration of the water treatment agent in the fluid system based on the system consumption of the target specie. 2. A method of regulating the in-system concentration of a water treatment agent in an industrial fluid system comprising: adding an inert tracer to an industrial fluid system, the inert tracer being added in known proportion to a target specie also being added to said industrial fluid system, wherein the system consumption of the target specie is effected by the water treatment agent; drawing a sample of fluid from said industrial fluid system; adding to the sample an incipient reagent in an amount effective to convert the target specie to a subject target specie indicator; monitoring the subject target-specie indicator by analysis of said sample to determine at least one characteristic that can be correlated to an in-system concentration of said target-specie; monitoring said inert tracer by analysis of said sample to determine the in-system concentration of said inert tracer; determining the system consumption of the target specie from the measured in-system concentration of the target specie and the inert tracer; and regulating the in-system concentration of the water treatment agent in the fluid system based on the system consumption of the target specie. 3. The method of claim 2 wherein said monitoring of said subject target-specie indicator is performed by fluorescence analysis of said sample to determine at least one fluorescence emission value that can be correlated to said in-system concentration of said target specie indicator. 4. The method of claim 2 wherein said subject target-specie indicator comprises a combination of said incipient reagent and a substantially nonfluorescent target specie, and wherein said correlation of said fluorescence emission value to said in-system concentration of said subject target-specie indicator is established by at least one difference between at least one fluorescence characteristic of said incipient reagent and one fluorescence characteristic of said subject target-specie indicator. 5. The method of claim 2 wherein said monitoring of said subject target-specie indicator is conducted at the site of said industrial system on a substantially continuous basis. 6. The method of claim 2 wherein at least one adjustment of said in-system concentration of said water treatment agent is made based on said system consumption for said target specie. 7. The method of claim 2 wherein said incipient reagent is substantially nonfluorescent and said subject target-specie indicator is fluorescent. 8. The method of claim 2 wherein said incipient reagent is fluorescent and said subject target-specie indicator is substantially nonfluorescent. 9. The method of claim 2 wherein both said incipient reagent and subject target-specie indicator are fluorescent, and wherein said fluorescence analysis is performed using a fluorescence analysis technique that at least minimizes interference between fluorescence emission of any residual incipient reagent and fluorescence emissions of said subject target-specie indicator. 10. The method of claim 2 further including feeding said water treatment agent to said fluid system together with a second inert tracer and monitoring the in-system concentration of said second inert tracer. 11. The method of claim 2 further including feeding said water treatment agent to said fluid system and monitoring the zero-consumption concentration of said water treatment agent and said target specie by fluorescence analysis by: (1) feeding said water treatment agent through a feed line to said fluid system as a component of a treatment product which contains a second inert tracer in known proportion to said water treatment agent; and (2) determining the concentration of said inert tracer and said second inert tracer within said fluid system. 12. The method of claim 2 wherein said target specie is sulfide, calcium, iron, carbonate, copper (bi)carbonate, alkalinity, copper, sulfate, fluoride, magnesium, and phosphate. 13. The method of claim 2 wherein said target specie is sulfide, calcium, iron, carbonate, copper and phosphate. 14. A method of target-specie responsive regulation of water treatment agent in-system concentration in an industrial fluid system comprising: drawing a sample of fluid from an industrial fluid system containing at least one target specie, wherein said system consumption of the target specie is affected by at least one water treatment agent; adding to said sample an incipient reagent in an amount effective to convert said target specie to a target-specie indicator which comprises a combination of said incipient reagent and said target specie; monitoring said target-specie indicator by fluorescence analysis of said sample to determine at least one fluorescence characteristic of said target-specie indicator that can be correlated to the in-system concentration of said target-specie indicator; correlating said in-system concentration of said target-specie indicator to an in-system concentration of said target specie; adding an inert tracer to said industrial fluid system in known proportion to the feed of said target specie to said industrial fluid system; monitoring said inert tracer by analysis of said sample to determine the in-system concentration of said inert tracer; correlating said in-system concentration of said inert tracer to a zero-consumption concentration of said target specie; determining the system consumption value for said target specie by subtracting said in-system concentration of said target specie from said zero-consumption concentration of said target specie; and regulating the in-system concentration of a water treatment agent in said fluid system based on said system consumption of the target specie. 15. The method of claim 14 wherein said target-specie is calcium. 16. The method of claim 14 wherein said target-specie indicator is a complex formed between calcium and 1,2-bis(o-aminophenoxy) ethane-N,N,N',N'-tetraacetic acid. -------------------------------------------------------------------------------- |
| PATENT DESCRIPTION |
TECHNICAL FIELD OF THE INVENTION The present invention is in the technical field of regulating the in-system concentration of water treatment agents and/or system operation, particularly the in-system concentration of water treatment agents in industrial water systems, such as cooling water systems, boiler water systems, water reclamation/purification systems, water systems of manufacturing processes and the like, by analysis of target specie(s) in the system, particularly scaling ions and contaminants, so as to increase the efficiency of the water treatment agents and/or operation of systems in which they are used. BACKGROUND OF THE INVENTION The in-system concentration of water treatment agents in industrial water systems is conventionally controlled based on intermittent measurements of the concentration of the target specie(s) and/or the concentration of the water treatment agent(s) in the water of the system or unselective measurements (e.g., conductivity). The control goal of most water-treatment programs is to maintain a predetermined or optimum ratio of water treatment agent(s) to target specie(s) (for instance scaling ions, contaminants and the like) in the water of the system. The in-system concentration of the water treatment agent(s) is regulated to attain or maintain this ratio or the target specie concentration is adjusted to meet specified values. For instance, if the concentration of hardness ions entering a boiler system increases, an increase in the in-system concentration of the water treatment agent(s) may be needed to maintain the water treatment agent(s) to target specie(s) ratio goal. The measurements of the concentration of the target specie(s) and/or the concentration of the water treatment agent(s) in the water of the system, and the responsive in-system concentration adjustments, are commonly based only on occasional grab samples, taken for instance once or twice per shift (a shift commonly encompassing about 8 to 12 hours of system operating time) or once every several days. Concentration determinations for water treatment agents and/or target species in industrial water systems have heretofore generally been based on classical (wet chemistry) analysis techniques, conductivity and/or hydraulic meter readings, for instance water flowmeter readings. Classical analysis techniques for determining the concentration of a target specie and water treatment agents in a water system are usually somewhat cumbrous and/or protracted, and/or provide results that are merely estimates and/or variable (for instance, dependent upon a person's laboratory technique). Long time delays typically exist between changes in system operation and a compensating change in treatment dosage. For example, phosphate concentrations are determined by a spectrophotometric (colorimetric) test. Concentrations of pyrophosphate and organic phosphorus compounds are determined using the same spectrophotometric test with a digestion (reversion) step. Titration methods are routinely employed to determine the concentration of hardness ions, such as calcium and magnesium, and the concentrations of carbonate and bicarbonate, in the water of the water system. Such analysis methods are susceptible to interferences (e.g., turbidity) and/or are subjective (visual observation of color change). These values, and often the ratio therebetween, are then used to manually set the in-system target concentration of the treatment chemicals, such as scale inhibitors and neutralizing amines. The more accurate a conventional manual (grab sample) analysis technique, the more protracted that technique or its response time can be. Feedback information can at times even be days behind the sampling and hence of little value in providing data from which a dosage-regulation response can be determined. The water system consumption of a water treatment agent may well have changed during the elapsed interval between the taking of the sample and the analysis results. Even when accurate indications of the mass or volume of a water treatment agent feed delivered to a system are available, and accurate water treatment agent residual concentrations are available, if the residual concentration determinations are based on grab or intermittent samples, any extrapolation therefrom to a value for the system demand and/or system consumption for the water treatment agent is based on fragmentary data and outdated information. A change in the system consumption may not be detected until it has had a significant impact on treatment agent consumption and system performance. When the detection of system consumption change is delayed, the responsive regulation of a treatment agent's in-system concentration or response to system operation will invariably be late and system performance may suffer. When the responsive regulation of in-system concentration is late, underfeeding or overfeeding of the treatment agent routinely will occur to some extent between the time the system consumption of the water treatment agent has changed and the time the treatment agent in-system concentration and/or system operating parameter (e.g., alkalinity adjustment) is adjusted. In an industrial water system plant the use of any estimated, variable, intermittent, fragmentary or historic data severely diminishes the sensitivity of any demand-responsive regulation of the water treatment agent in-system concentration and/or diminishes the ability to follow changes in the treatment-agent system demand or system consumption with appropriate compensations to the water treatment agent in-system concentration. Conventional procedures for regulating water treatment agent in-system concentration are further complicated by other imprecise evaluations of operating parameters. The rates at which the water treatment agent is being fed to and/or removed from the industrial water system and/or other operating parameters having an influence on the in-system concentration of the water treatment, may defy precise measurement unless inert tracers and selective analytical methods are used. The readings and/or settings on feed and blowdown equipment and/or lines are seldom unquestionably reliable and often complicated by multiple sources of blowdown and makeup and changes in composition of these water samples. Fluctuations in the concentrations in the target species and the water treatment agent may stem from a variety of system conditions, such as dilution when other materials are charged to the system, concentration by evaporation or other means, unaccounted loss of fluid from the system and the like, some of which parameters may not be accurately known. Generally all sources of water intake and loss, and all sources of water treatment agent intake and loss, cannot be known precisely and continuously unless inert tracers and selective analytical methods are used. A sensitive, selective and rapid demand-responsive control of water treatment agent in-system concentration would render most any industrial water system more efficient. Overfeeding of a water treatment agent is unnecessarily expensive, may at times diminish the recycling potential of waste water discharged from the system and may also at times impair system operation. Underfeeding of a water treatment agent almost inevitably impairs system operation, the imbalance between an underfed water treatment agent and the target species leading to higher levels of deleterious effect(s) from which relief is sought by the water treatment. In some water systems an imbalance between the in-system concentrations of water treatment agents and the system's water conditions and/or target species can severely diminish the efficiency of the system. For instance the efficiency of a system's temperature conditioning performance, such as heat exchange and steam generation, may be reduced which in turn may diminish the performance of a process to which it is adjuvant. A sensitive, selective and rapid demand-responsive regulation of water treatment agent in-system concentration that permits the in-system concentration of water treatment agent(s) to be adjusted in response to real-time system conditions is not provided by the conventional methods. It is an object of the present invention to provide a method or process for monitoring the concentration of a target specie(s) in a water system, thereby permitting a responsive regulation of the in-system concentration of one or more water treatment agents and/or adjustment of system operating parameters (e.g., alkalinity, etc.) It is an object of the present invention to provide such a method or process that can be conducted on-site in a very short time period. It is an object of the present invention to provide such a method or process further including the regulation of the in-system concentration of at least one water treatment agent and/or system operating parameter in an industrial water system in response thereto. It is an object of the present invention to provide such a method or process that can be conducted on-site in a very short time period, preferably on a continuous basis. It is an object of the present invention to provide in an industrial water system one or more monitorings of target specie(s) on-site in a very short time period, preferably on a continuous basis. These and other objects of the present invention are discussed in detail below. SUMMARY OF THE INVENTION The present invention provides a demand-responsive management (regulation or control) of water treatment agent in-system concentration(s) and/or system operating parameter(s), for instance by regulating water treatment agent feed, which includes the monitoring of the value of a target-specie indicator, preferably by fluorescence analysis. The present invention provides a process for the regulation of at least one water treatment agent in-system concentration and/or system operating parameter, based on the value of at least one target specie for that treatment agent and/or operating parameter, comprising monitoring a fluorescent characteristic of at least one target-specie indicator that is itself a target specie or is a combination of an incipient reagent and a target specie. The target specie for instance may be a chemical specie, sealants, corrosion products, corrosive agents, foulants or a water condition, such as pH, that is targeted by the treatment agent, that is, indicia of system demand and/or system consumption for a water treatment agent or scaling/deposit forming, fouling, or corrosive conditions. In more detail, the target specie may be a chemical specie that is produced by another chemical specie or by a water condition, for instance corrosion products. The target specie may be a system-demanding and/or system consumption condition, for instance system pH. The target specie may be other types of indicia of system consumption for a water treatment agent that itself is, or in combination with a suitable reagent forms, a target-specie indicator having a fluorescent characteristic which can be correlated to the value of the target specie. That fluorescent characteristic is monitored, preferably on a continuous basis, by at least one fluorescence analysis method and the results of such monitoring preferably are correlated to a regulation of the in-system concentration of such treatment agent and/or system operating parameter. According to other preferred embodiments of the invention, the target-specie is monitored by other election means, including, but not limited to, light absorbance, chemiluminescence and ion-selective electrode. The present method also provides a demand-responsive management (regulation or control) of water treatment agent in-system concentration based on system demand for the target specie. In preferred embodiments, the present invention further includes the monitoring of an inert tracer, which together with the monitoring of the target-specie indicator is used to determine system demand for the target specie, which is described in detail below. In further preferred embodiments, the effects of target-specie responsive adjustments to the treatment agent's in-system concentration are tracked by a continuous monitoring of the target-specie indicator, preferably in combination with a continuous monitoring of an inert tracer, which is described in detail below. |
| PATENT EXAMPLES | available on request |
| PATENT PHOTOCOPY | available on request |
|
Want more information ? Interested in the hidden information ? Click here and do your request. |