Hydroxyapetite is softer than other deposits and will remain in suspension as long as it is kept in circulation. Monitoring Contaminants is a subject that always interests me. The term "active tracer", as used herein, refers to tracers that provide some performance benefit downstream of the sample point and/or are consumed or have their tracer characteristic changed by chemical alteration to some extent within the boiler system downstream of the sample point. The method of any of Claims 1 - 11 wherein at least one of said phosphate-feed tracer and said blowdown tracer is a sulfonated derivative of pyrene. Marcy and Halsted firstly established the concepts and limits for Congruent Phosphate in 1964. pH value, Control of chemical or physico-chemical variables, e.g. Therefore, as discussed above, the required feedwater purity is very high and the permitted concentration of impurities introduced with the feedwater is very low. In more preferred embodiment, at least one of the phosphate-feed tracer and the blowdown tracer is a water-soluble salts of 2-naphthalene sulfonic acid or 1,5-naphthalene disulfonic acid. In preferred embodiment, the phosphate-feed tracer is an inert tracer that is added to the water of the boiler system in an amount at least sufficient to provide a concentration of the inert tracer in the blowdown at steady state of at least about 0.1 ppm. The terms "tracer" or "tracer(s), as used herein, refer to any and all of the tracers used in the present process, regardless of whether a given tracer is active or inert and regardless of whether a given tracer is a "feedwater tracer", a "phosphate-feed tracer" and/or a "blowdown tracer" as these terms are used and defined herein. High pressure boiler users such as pulp producing sites always faced many challenges on getting the boiler water chemistry under control. Removal of calcium and magnesium to below 0.5 ppm as calcium carbonate. Essentially pure HO leaves the boiler as steam. The big challenge is to maintain the Na:PO4 ratio inside the establish limits. Two phosphate-based programs of the pH/phosphate type provide low-alkalinity boiler water treatments. A TRI-AD program's primary advantage in systems where it has been shown to be acceptable is that it provides a small reservoir of excess caustic that can: In Figure 3 are shown the control parameters for coordinated programs of the Congruent Control and TRI-AD types. When the tracer is 2-NSA, one of the water-soluble salts of naphthalene sulfonic acid ("NSA"), its concentration in the feedwater and/or blowdown from a boiler system can be fluorometrically measured by excitation at 277 nm and emission measurement at 334 nm, and the emissions observed referenced to a standard aqueous solution containing 0.5 ppm 2-NSA, as acid actives. This balance between the rate of introduction of impurities ("solids") to a boiler together with feedwater and the rate of solids discharge from the boiler with blowdown may be represented by a hypothetical boiler operation example as follows: The desired cycles value for such a boiler balance is 100/10 = 10. Unless expressly indicated otherwise herein, the inclusion of a prefix or suffix in parenthesis designates the word with such prefix or suffix as an alternative. Phosphate feeds comprised of monosodium phosphate and caustic in combination may provide wide flexibility. This plant is equipped with two high pressure recovery boilers (85 bar). The method of any of claims 1 - 4 wherein said phosphate-feed tracer is a fluorescent tracer and said concentration of said phosphate-feed tracer in said phosphate-feed stream is substantially continuously monitored on-line by sensing the fluorescent characteristic of said phosphate-feed tracer in said phosphate-feed stream. NOTARBARTOLO & GERVASI S.P.A. Ref document number: Measures taken against scale deposits and/or corrosion depend on the characteristics of the boiler and the boiler feedwater. The concentration of any substance in blowdown, therefore, is commensurate with the concentration of that substance in the boiler at the time the blowdown is discharged from the boiler. The most commonly used precipitating agents are carbonate and phosphate. Thus, varying degrees of deposition are generally found in phosphate-treated boilers where hardness incursion has occurred. These and other contaminants may enter a boiler in soluble form, and then precipitate in the vicinity of the hot boiler surfaces. In more preferred embodiment, a feedwater-tracer is added to the boiler in the feedwater, wherein the feedwater tracer and the phosphate-feed tracer are the same tracer or different tracers, and wherein at least one of the phosphate-feed tracer and the feedwater tracer is an active tracer that is an aromatic azole. It is an object of the present invention to provide a pH/phosphate program control method of great sensitivity that is independent of small impurity variations in the boiler feedwater. Monitor chemical injection practices closely during phosphate hideout and return conditions. In preferred embodiment, the phosphate is fed to the feedwater stream by a phosphate pump upstream of the boiler and the phosphate-feed stream is the feedwater stream downstream of the phosphate pump. Film boiling, the second primary cause of caustic gouging, occurs when the heat input (heat flux) to a given section of boiler tube surface is so high that an orderly transfer of the heat from the tube surface to the steam-water mixture does not take place, leading to the formation of highly concentrated, nonboiling liquid films. When the electron's excited state relaxes from a higher energy vibrationally-excited state to the lowest energy vibrationally-excited state, energy is lost in the form of heat. Above that boundary, the equivalent of trisodium phosphate and caustic exist. ORIGINAL CODE: 0009210, Kind code of ref document: 
Phosphates can be fed into the system in solution with other water conditioning chemicals. Since this was quite and old site, many variables interfere directly at the in the box control results, such as: - very long and large chemical feed lines, - feedwater quality upsets and disturbances, - manual adjustment of chemical treatment products. Figure 4 shows the results before and after application of Knowledge Based Control approach by the new controller. One of the worst types of scale buildup is calcium carbonate, commonly known as limestone. Boiler feedwater, which normally is comprised of both makeup water and recirculated condensate water, contains some impurities regardless of the extent to which such waters are treated before being fed to a boiler. The ratio of Na:PO4 in CBD of boiler feed water is about 0.5 and if i multiply Na+ and PO4 (3-) in their molecular weight, the Na:PO4 molar ration is about 0.1 (Is my calculation true for measuring molar ratio of Na:PO4 ? The inert tracer preferably is employed to determine the cycles (impurity or contaminant concentration within the boiler water) on a continuous basis. Just as phosphate disappears with increasing load, so does it reappear with decreasing load, with concurrent impact on the system pH. Since the predominant chelation reactions take place in the boiler feedwater and not in the boiler water, considerable care must be given to selecting the proper chemical feed points. Be reasonably nontoxic and environmentally safe, not only within the environs of the water of the boiler system in which it may be used, but also upon discharge therefrom. Sodium phosphates help fulfill this requirement. Depending upon the period, it could range from 40 up to 70% of the time in the box. 8. That is, the concentration of solids in the blowdown should be 10 times the concentration of solids in the feedwater. The use of fluorescence emission spectroscopy for the analysis of aromatic(thio)(tri)azoles is discussed in more detail in U.S. Patent Application Serial No. The blowdown tracer must be inert, and it may also be the feedwater tracer and/or the phosphate-feed tracer. On most installations, OnGuard iController is adjusted to control the automatic dosage of the low and high pH phosphate blend, and also other regular products in chemical programs (dispersant, oxygen scavenger and neutralizing amines). Enhanced phosphate treatment for drum. The intricate phosphate chemistry that controls these two programs requires very pure feedwater, with make-up water of demineralized or evaporated quality. There are water-soluble inert tracer(s) that are wholly inert, or substantially inert, in the aqueous environments likely to be encountered in industrial boiler systems. In more preferred embodiment, at least one of the phosphate-feed tracer and the blowdown tracer is a 1,3,6,8-pyrene tetrasulfonic acid or water-soluble salt thereof. This article describes the results of the knowledge based control applied to the high pressure boilers at a pulp mill and show precise conclusions for this controller. The concentration of solids within the boiler 12 at any given time, after steady state is reached, should also fall within predetermined limits. It is not well suited for continuous monitoring and/or control. The method of any of Claims 1 - 17 wherein said phosphate-feed tracer is an inert tracer that is added to the water of said boiler system in an amount at least sufficient to provide a concentration of said inert tracer in the blowdown at steady state of at least about 0.1 ppm. After introduction to the boiler it would not precisely follow the phosphate in the system, and instead it can then act as a blowdown tracer for the boiler-cycles determination purposes of the present invention. Although it is not new, it is by far the best choice where there can be feedwater contamination in some level. The detection and quantification of specific substances by fluorescence emission spectroscopy is founded upon the proportionality between the amount of emitted light and the amount of a fluoresced substance present. In preferred embodiment, the combination of the chemical compound(s) selected as the tracer(s) and the analytical technique selected for determining the presence of such tracer(s), permits such determination without isolation of the tracer(s), and more preferably should permit such determination on a continuous and/or on-line basis. 1. Polymers can be used in conjunction with phosphate programs to condition the precipitated compounds, prevent their accumulation, and aid in their removal from the boiler. Waste-heat boilers receive heat from process streams for the production of steam. Such tracer(s) may be a component of a formulated phosphate product, and in most instances it would be a compound(s) added to the formulated phosphate product, or otherwise added to the water system in proportion to the phosphate. Non-Phosphorus, Non-Zinc Cooling Treatment, Environmental, Social, & Corporate Governance, Cooling Scale Inhibitors and Deposition Control, Infrequent operator attention and testing, Water softeners are in use, but control is less than ideal, Boiler design, operating pressure, and steam production rates are compatible with precipitating chemistries, High iron levels (>0.5 ppm) in the feedwater, Feedwater hardness greater than ASME guidelines (>1.0 ppm), Exceptional boiler internal cleanliness required. Such boilers are often, but not necessarily, high pressure, high heat transfer rate boilers that can tolerate almost no solids internally. The discharged steam is replaced by contaminant-containing feedwater. Among the various types of corrosion inhibitors are organic compounds, which act by adsorbing or chemisorbing as thin layers on metal surfaces to separate the water and metal. An ever increasing concentration of dissolved and suspended solids in the boiler water would inevitably result in very serious problems, including deposit formation, corrosion, foaming, mechanical and selective carryover, decreased heat transfer efficiency, boiler tube failure or occlusion, and the like.
Phosphates can be fed into the system in solution with other water conditioning chemicals. Since this was quite and old site, many variables interfere directly at the in the box control results, such as: - very long and large chemical feed lines, - feedwater quality upsets and disturbances, - manual adjustment of chemical treatment products. Figure 4 shows the results before and after application of Knowledge Based Control approach by the new controller. One of the worst types of scale buildup is calcium carbonate, commonly known as limestone. Boiler feedwater, which normally is comprised of both makeup water and recirculated condensate water, contains some impurities regardless of the extent to which such waters are treated before being fed to a boiler. The ratio of Na:PO4 in CBD of boiler feed water is about 0.5 and if i multiply Na+ and PO4 (3-) in their molecular weight, the Na:PO4 molar ration is about 0.1 (Is my calculation true for measuring molar ratio of Na:PO4 ? The inert tracer preferably is employed to determine the cycles (impurity or contaminant concentration within the boiler water) on a continuous basis. Just as phosphate disappears with increasing load, so does it reappear with decreasing load, with concurrent impact on the system pH. Since the predominant chelation reactions take place in the boiler feedwater and not in the boiler water, considerable care must be given to selecting the proper chemical feed points. Be reasonably nontoxic and environmentally safe, not only within the environs of the water of the boiler system in which it may be used, but also upon discharge therefrom. Sodium phosphates help fulfill this requirement. Depending upon the period, it could range from 40 up to 70% of the time in the box. 8. That is, the concentration of solids in the blowdown should be 10 times the concentration of solids in the feedwater. The use of fluorescence emission spectroscopy for the analysis of aromatic(thio)(tri)azoles is discussed in more detail in U.S. Patent Application Serial No. The blowdown tracer must be inert, and it may also be the feedwater tracer and/or the phosphate-feed tracer. On most installations, OnGuard iController is adjusted to control the automatic dosage of the low and high pH phosphate blend, and also other regular products in chemical programs (dispersant, oxygen scavenger and neutralizing amines). Enhanced phosphate treatment for drum. The intricate phosphate chemistry that controls these two programs requires very pure feedwater, with make-up water of demineralized or evaporated quality. There are water-soluble inert tracer(s) that are wholly inert, or substantially inert, in the aqueous environments likely to be encountered in industrial boiler systems. In more preferred embodiment, at least one of the phosphate-feed tracer and the blowdown tracer is a 1,3,6,8-pyrene tetrasulfonic acid or water-soluble salt thereof. This article describes the results of the knowledge based control applied to the high pressure boilers at a pulp mill and show precise conclusions for this controller. The concentration of solids within the boiler 12 at any given time, after steady state is reached, should also fall within predetermined limits. It is not well suited for continuous monitoring and/or control. The method of any of Claims 1 - 17 wherein said phosphate-feed tracer is an inert tracer that is added to the water of said boiler system in an amount at least sufficient to provide a concentration of said inert tracer in the blowdown at steady state of at least about 0.1 ppm. After introduction to the boiler it would not precisely follow the phosphate in the system, and instead it can then act as a blowdown tracer for the boiler-cycles determination purposes of the present invention. Although it is not new, it is by far the best choice where there can be feedwater contamination in some level. The detection and quantification of specific substances by fluorescence emission spectroscopy is founded upon the proportionality between the amount of emitted light and the amount of a fluoresced substance present. In preferred embodiment, the combination of the chemical compound(s) selected as the tracer(s) and the analytical technique selected for determining the presence of such tracer(s), permits such determination without isolation of the tracer(s), and more preferably should permit such determination on a continuous and/or on-line basis. 1. Polymers can be used in conjunction with phosphate programs to condition the precipitated compounds, prevent their accumulation, and aid in their removal from the boiler. Waste-heat boilers receive heat from process streams for the production of steam. Such tracer(s) may be a component of a formulated phosphate product, and in most instances it would be a compound(s) added to the formulated phosphate product, or otherwise added to the water system in proportion to the phosphate. Non-Phosphorus, Non-Zinc Cooling Treatment, Environmental, Social, & Corporate Governance, Cooling Scale Inhibitors and Deposition Control, Infrequent operator attention and testing, Water softeners are in use, but control is less than ideal, Boiler design, operating pressure, and steam production rates are compatible with precipitating chemistries, High iron levels (>0.5 ppm) in the feedwater, Feedwater hardness greater than ASME guidelines (>1.0 ppm), Exceptional boiler internal cleanliness required. Such boilers are often, but not necessarily, high pressure, high heat transfer rate boilers that can tolerate almost no solids internally. The discharged steam is replaced by contaminant-containing feedwater. Among the various types of corrosion inhibitors are organic compounds, which act by adsorbing or chemisorbing as thin layers on metal surfaces to separate the water and metal. An ever increasing concentration of dissolved and suspended solids in the boiler water would inevitably result in very serious problems, including deposit formation, corrosion, foaming, mechanical and selective carryover, decreased heat transfer efficiency, boiler tube failure or occlusion, and the like.