Digestion system and total iron rapid detection system based on high-pressure digestion and coordination reaction

Abstract

The invention discloses a digestion system and a total iron rapid detection system based on high-pressure digestion and coordination reaction, the digestion system comprises a digestion cuvette and a digestion system shell, the digestion cuvette is located in the digestion system shell, a heater is arranged on the outer wall of the digestion cuvette, and the digestion cuvette is located in the digestion system shell. A digestion cuvette upper end electromagnetic valve and a digestion cuvette lower end electromagnetic valve are arranged on the outer wall of the digestion system shell, the upper end of the digestion cuvette is communicated with the digestion cuvette upper end electromagnetic valve, and the lower end of the digestion cuvette is communicated with the digestion cuvette lower end electromagnetic valve. Reaction conditions are easy to realize, and measurement lower limit is reduced.

Description

Technical Field

[0001] This invention belongs to the field of total iron detection technology, and relates to a digestion system and a rapid total iron detection system based on high-pressure digestion and complexation reaction. Background Technology

[0002] The total iron content in the steam-water system of a power plant is a crucial indicator of corrosion products. Excessive iron content can cause flow-accelerated corrosion (FAC), scaling, and other operational problems, leading to increased boiler operating pressure differential, accelerated scaling rates on heat exchange surfaces, reduced turbine flow area, and decreased unit efficiency. Therefore, rapid and accurate monitoring of the total iron content in the steam-water system is essential for supervising the quality of steam-water in generator units and ensuring their safe operation. Currently, the measurement of total iron content in water in power systems primarily employs manual spectrophotometric analysis methods, typically the sulfosalicylic acid spectrophotometric method and the o-phenanthroline spectrophotometric method.

[0003] The sulfosalicylic acid spectrophotometric method refers to DL / T 502.25-2019 "Methods for Analysis of Water and Steam in Thermal Power Plants - Part 25: Determination of Total Iron". The basic principle is as follows: ammonium persulfate and hydrochloric acid are added to the sample, and boiling is required to oxidize the ferrous ions in the water sample to ferric ions. Under pH conditions of 9-11, the ferric ions react with sulfosalicylic acid to form a yellow complex, and the total iron content in the water is determined by measuring the absorbance using a spectrophotometer. The o-phenanthroline spectrophotometric method is based on the following principle: hydroxylamine hydrochloride and hydrochloric acid are added to the sample, and boiling is required. Under pH conditions of 4-5, ferrous ions react with o-phenanthroline to form a red complex, and the total iron content in the water is determined by measuring the absorbance using a spectrophotometer.

[0004] The technical drawback of the above analytical methods is that:

[0005] The above measurement method is a manual analysis method. Because it requires converting colloidal iron into dissolved iron and then oxidizing or reducing it, the water sample needs to be boiled. The measurement steps are cumbersome and time-consuming, taking about 1 hour. This makes it impossible to measure total iron quickly, which seriously affects the unit's rapid grid connection and power generation. In addition, this method is suitable for measuring total iron content of 5-10000 ppb. During unit operation, the total iron content in water vapor needs to be controlled below 5 μg / L. For trace amounts of total iron, the detection limit of this method cannot meet the requirements for accurate measurement.

[0006] The sulfosalicylic acid spectrophotometric method for measuring ferric iron in solution requires the addition of an additional oxidant (persulfate) to ensure that all dissolved iron ions are ferric. Furthermore, the colorimetric range of this method is 9-11, and an alkalizing agent is required to strictly control the pH of the reaction solution.

[0007] The 1,000-phenanthroline spectrophotometric method for measuring ferrous iron in solution requires the addition of an additional reducing agent (hydroxylamine hydrochloride) to ensure that all dissolved iron ions are ferrous. Furthermore, the colorimetric range of this method is 4-5, and the pH of the reaction solution needs to be strictly controlled by adding an alkalizing agent or buffer solution.

[0008] In summary, the above methods for measuring total iron are cumbersome, time-consuming, require stringent reaction conditions, and have relatively high measurement limits. Summary of the Invention

[0009] The purpose of this invention is to overcome the shortcomings of the prior art and provide a digestion system and a rapid detection system for total iron based on high-pressure digestion and coordination reaction. This system can detect total iron, and the detection steps are simple, efficient, and the reaction conditions are easy to achieve, while the lower limit of measurement is reduced.

[0010] To achieve the above objectives, the present invention discloses a digestion system, including a digestion tank and a digestion system housing. The digestion tank is located inside the digestion system housing, and a heater is provided on the outer wall of the digestion tank. An upper solenoid valve and a lower solenoid valve of the digestion tank are provided on the outer wall of the digestion system housing. The upper end of the digestion tank is connected to the upper solenoid valve of the digestion tank, and the lower end of the digestion tank is connected to the lower solenoid valve of the digestion tank.

[0011] A further improvement of the digestion system described in this invention is that:

[0012] Furthermore, a cooling system is provided on the outer wall of the digestion system shell.

[0013] This invention discloses a rapid detection system for total iron based on high-pressure digestion and complexation reaction, comprising an acid addition module, a reaction system, a colorimetric system, a compounding reagent dosing device, and the digestion system as described in the claims. The outlet of the water sample pipeline to be tested and the outlet of the acid addition module are connected to the inlet of the digestion system. The outlet of the digestion system and the outlet of the compounding reagent dosing device are connected to the inlet of the reaction system. The outlet of the reaction system is connected to the inlet of the colorimetric system.

[0014] The further improvement of the rapid total iron detection system based on high-pressure digestion and complexation reaction described in this invention lies in:

[0015] Furthermore, the compounding agents include K4[Fe(CN)6] and K3[Fe(CN)6].

[0016] Furthermore, the K4[Fe(CN)6] content in the compounding reaction agent is 0.55 g / L.

[0017] Furthermore, the content of K3[Fe(CN)6] in the compounding reaction agent is 0.50 g / L.

[0018] Furthermore, the reaction system is equipped with a temperature control device.

[0019] Furthermore, the reaction system is equipped with a stirring device.

[0020] Furthermore, a cooling system is provided on the outer wall of the digestion system shell.

[0021] Furthermore, the colorimetric system is based on spectrophotometry, where the absorbance and color of the solution conform to Beer-Lambert law, in order to calculate the total iron content of the water sample being tested.

[0022] The present invention has the following beneficial effects:

[0023] In practical operation, the digestion system and the rapid total iron detection system based on high-pressure digestion and complexation reaction described in this invention have a heater installed on the outer wall of the digestion tank. The outer wall of the digestion system shell is equipped with an upper solenoid valve and a lower solenoid valve for the digestion tank. The digestion system can provide higher dissolution temperature and pressure, reducing the time required for colloidal iron dissolution from approximately 1 hour to 3 minutes. The complexation reaction reagent provided in this invention can simultaneously react with ferrous and ferric iron to generate the same complexation product. The measurement process does not require additional redox reagents or a stringent pH colorimetric environment. Using this invention, rapid and accurate detection and analysis of total iron content in water samples is achieved, providing data support for the rapid start-up of similar units such as thermal power plants. Attached Figure Description

[0024] The accompanying drawings, which form part of this specification, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0025] Figure 1a This is a structural diagram of the digestion system of the present invention;

[0026] Figure 1b This is a side view of the digestion system in this invention;

[0027] Figure 2 This is a structural diagram of the present invention.

[0028] Among them, 1 is the upper solenoid valve of the digestion tank, 2 is the lower solenoid valve of the digestion tank, 3 is the digestion tank, 4 is the cooling system, and 5 is the outer shell of the digestion system. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] In the description of this invention, it should be understood that the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0031] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0032] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes such combinations. For example, A and / or B can represent three cases: A alone, A and B simultaneously, and B alone. Additionally, the character " / " in this invention generally indicates that the preceding and following objects have an "or" relationship.

[0033] It should be understood that although terms such as first, second, third, etc., may be used in the embodiments of the present invention to describe the preset range, these preset ranges should not be limited to these terms. These terms are only used to distinguish the preset ranges from one another. For example, without departing from the scope of the embodiments of the present invention, the first preset range may also be referred to as the second preset range, and similarly, the second preset range may also be referred to as the first preset range.

[0034] Depending on the context, the word "if" as used here can be interpreted as "when," "when," "in response to determination," or "in response to detection." Similarly, depending on the context, the phrase "if determination" or "if detection (of the stated condition or event)" can be interpreted as "when determination," "in response to determination," "when detection (of the stated condition or event)," or "in response to detection (of the stated condition or event)."

[0035] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0036] The accompanying drawings illustrate various structural schematic diagrams according to embodiments disclosed in this invention. These drawings are not to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0037] As is generally known, a colorimetric system is a technical system that determines the color or concentration of a substance based on its light absorption characteristics through optical measurement and data analysis. Its core principles, composition, types, and applications are as follows:

[0038] I. Core Principles

[0039] Fundamentals of optical absorption: The absorption of light by a substance follows the Lambert-Beer law (A = εCL), meaning that the absorbance (A) is directly proportional to the solution concentration (C), the optical path length (L), and the extinction coefficient (ε). By measuring the degree of light absorption at a specific wavelength, the concentration or color parameters of a substance can be deduced.

[0040] Human eye perception simulation: Some systems (such as the Lovibond colorimeter) simulate the human eye's perception mechanism of the four primary colors: red, yellow, blue, and gray. Through color filter combinations or spectral analysis, colors are converted into quantifiable numerical values ​​(such as Lovibond units).

[0041] II. System Composition

[0042] Light source: Provides light with a stable wavelength (such as halogen tungsten lamps, xenon lamps, LEDs), covering the wavelength range from visible light to near-infrared (325-800nm). The color rendering index (CRI) needs to be ≥90, and the color temperature should be close to sunlight (5500-6500K) to reduce ambient light interference.

[0043] Sample chamber: Contains the sample to be tested (such as a cuvette or microfluidic chip), ensuring full interaction between the optical path and the sample. Advanced systems are equipped with temperature control modules (such as 25°C or 37°C) to control reaction conditions.

[0044] Monochromator: Interference filter: Low cost, but wide wavelength bandwidth (>10nm), limited testing accuracy. Grating spectrometer: Wavelength bandwidth <6nm, high spectroscopic accuracy, suitable for high-precision measurements.

[0045] Detector: A photodiode or silicon photodiode array converts the optical signal into an electrical signal. The digital signal is transmitted through optical fibers to avoid electromagnetic interference.

[0046] Data processing system: A computer or embedded chip analyzes electrical signals and outputs color parameters (such as Lab* values, Lovibond units) or concentration values. Advanced system integration AI algorithms enable automatic calibration, multi-channel data parsing, and error correction.

[0047] III. System Types

[0048] Traditional colorimeters: Visual colorimetry: Color differences are manually judged by comparing a standard color chart with the sample (e.g., the Munsell colorimetric system). Photoelectric colorimetry: A photoelectric detector replaces the human eye, improving measurement stability, but wavelength selection depends on the filter.

[0049] Spectrophotometer:

[0050] It covers a wider wavelength range (200-1000nm) and achieves high-precision measurement through grating spectral dispersion. It is applied in scientific research, pharmaceuticals and other fields, and can simultaneously determine the concentration of multiple components.

[0051] Fully automated colorimetric system: Integrates light source, sample chamber, detector, and data processing module to achieve automated measurement (e.g., PFXi195 series). Equipped with intelligent algorithms, it supports remote monitoring, data storage, and analysis report generation.

[0052] Intelligent colorimetric sensing technology: Gas detection: A composite hydrogel sensor based on chelation reaction, combined with deep learning algorithms, enables ultrafast detection of gases such as hydrogen sulfide. Wearable devices: Flexible mechanoluminescent thin-film sensors monitor strain or biomarkers (such as vitamin C and pH in tears) through color changes.

[0053] Example 1

[0054] refer to Figure 1a and Figure 1bThe digestion system of the present invention includes a digestion tank 3, which is located inside the digestion system shell 5. A heater is installed on the outer wall of the digestion tank 3. A cooling system 4, an upper solenoid valve 1 and a lower solenoid valve 2 are installed on the outer wall of the digestion system shell 5. The upper end of the digestion tank 3 is connected to the upper solenoid valve 1, and the lower end of the digestion tank 3 is connected to the lower solenoid valve 2.

[0055] Example 2

[0056] This invention discloses a working method of a digestion system. The digestion system includes a digestion tank 3, which is located inside a digestion system shell 5. A heater is installed on the outer wall of the digestion tank 3. A cooling system 4, an upper solenoid valve 1, and a lower solenoid valve 2 are installed on the outer wall of the digestion system shell 5. The upper end of the digestion tank 3 is connected to the upper solenoid valve 1, and the lower end of the digestion tank 3 is connected to the lower solenoid valve 2.

[0057] Specifically, the following steps are included:

[0058] 1) Open the upper solenoid valve 1 and the lower solenoid valve 2 of the digestion tank at the same time to ensure that the water sample enters the digestion tank 3.

[0059] 2) After acidification with hydrochloric acid or sulfuric acid solution (sample pH controlled below 2.0), the sample enters the digestion tank 3 from the bottom of the digestion tank 3 through the solenoid valve 2 at the bottom of the digestion tank. The internal space of the digestion tank 3 is 25 mL, and the sample injection volume is controlled between 15 and 20 mL.

[0060] 3) Close the upper solenoid valve 1 and the lower solenoid valve 2 of the digestion tank at the same time, and turn on the heater. Since the digestion tank 3 is in a closed and pressurized state at this time, the solution in the digestion tank 3 can be heated to above 100°C. The heating temperature of this system is 120-150°C.

[0061] 3) After the solution temperature rises to the set temperature (e.g., 150℃), keep it at that temperature for 3 minutes. Since the dissolution temperature and pressure are much higher than those of traditional open-air atmospheric pressure heating, the dissolution reaction of colloidal iron is accelerated, and the dissolution process can be completed in 3 minutes.

[0062] 4) After the constant temperature reaction is completed, turn on the cooling system 4 to reduce the solution temperature from 150℃ to below 50℃, and then open the upper solenoid valve 1 and the lower solenoid valve 2 of the digestion tank at the same time, so that the solution in the digestion tank 3 is discharged from the lower end of the digestion tank 3.

[0063] In the above steps, the injection time is 0.5 min, the heating time is 1.5 min, the isothermal time is 3 min, the cooling time is 2.5 min, and the sample dispensing time is 0.5 min. In summary, the entire dissolution process takes 8.0 min, which is far superior to traditional manual analysis methods and lays the foundation for the rapid determination of total iron in samples.

[0064] Example 3

[0065] The rapid detection system for total iron based on high-pressure digestion and complexation reaction of the present invention includes an acid addition module, a reaction system, a colorimetric system, and a dosing device for compounding reaction reagents;

[0066] The outlet of the water sample pipeline to be tested and the outlet of the acid addition module are connected to the inlet of the digestion system. The outlet of the digestion system and the outlet of the compounding reagent dosing device are connected to the inlet of the reaction system. The outlet of the reaction system is connected to the inlet of the colorimetric system.

[0067] Furthermore, addressing the technical shortcomings of traditional manual analysis methods that require oxidizing dissolved iron to trivalent or reducing it to divalent iron during the colorimetric stage and necessitate a strictly controlled pH environment, this invention proposes a novel complex chelating agent based on the coordination reaction mechanism. This agent can react with either divalent or trivalent ferrous ions to generate the same colorimetric substance. Based on this agent, no additional redox reagents are needed after dissolving colloidal iron, nor is it necessary to use alkalizing agents or buffer solutions to provide an appropriate pH environment.

[0068] Specifically, the composition and formulation of the compound reaction agent are as follows:

[0069] Ingredient 1: K4[Fe(CN)6]; 368.343

[0070] Ingredient 2: K3[Fe(CN)6]; 329.24

[0071] The mass ratio of component 1 to component 2 is 1.1:1.0. The compounding reaction agent is a liquid solution, wherein the content of K4[Fe(CN)6] is 0.55 g / L and the content of K3[Fe(CN)6] is 0.50 g / L. This formula can be used to detect and analyze the total iron content within 1000 ppb.

[0072] Ferric ions in the water sample can undergo a complexation reaction with K3[Fe(CN)6] in the complexation reagent to form a blue K[Fe(CN)6Fe] complex. Similarly, ferric ions can undergo a complexation reaction with K4[Fe(CN)6] in the complexation reagent, also forming a blue K[Fe(CN)6Fe] complex. The reaction equations are as follows:

[0073] K + +Fe 3++[Fe(CN)6] 4- =K[Fe(CN)6Fe]

[0074] K + +Fe 2+ +[Fe(CN)6] 3- =K[Fe(CN)6Fe]

[0075] Therefore, the above-mentioned complexing reagent reacts with both ferrous and ferric ions to produce the same blue complexing reaction product, avoiding the oxidation or reduction steps in traditional manual analysis methods.

[0076] Based on the high-pressure digestion and complexation reaction proposed in this invention, a rapid detection system for total iron in water samples can be formed, and the system flowchart is shown in Figure 2.

[0077] Example 4

[0078] This embodiment discloses a working method for a rapid total iron detection system based on high-pressure digestion and complexation reaction. The rapid total iron detection system based on high-pressure digestion and complexation reaction includes an acid addition module, a reaction system, a colorimetric system, and a compounding reagent dosing device. The outlet of the water sample pipeline to be tested and the outlet of the acid addition module are connected to the inlet of the digestion system. The outlet of the digestion system and the outlet of the compounding reagent dosing device are connected to the inlet of the reaction system. The outlet of the reaction system is connected to the inlet of the colorimetric system.

[0079] Specifically, the following steps are included:

[0080] 1) The water sample to be tested and a quantitative amount of hydrochloric acid or sulfuric acid solution are introduced into the digestion system to convert colloidal iron. This process takes 8 minutes.

[0081] 2) After the converted sample is cooled, it is introduced into the reaction system, and 0.15–0.20 mL of the compounded reaction agent is added simultaneously. The reaction system has built-in temperature control and stirring functions. During the reaction, the temperature is maintained at around 50°C, and the stirring rotor speed is 300–500 rpm; the reaction takes 2 minutes.

[0082] 3) The reacted sample is sent into the colorimetric system. The colorimetric system is based on spectrophotometry. The absorbance and color of the solution conform to Beer-Lambert law, so the total iron content of the water sample can be calculated. The colorimetric process takes 1 minute.

[0083] In summary, the process of measuring total iron content in water using this invention takes approximately 11 minutes, which is shorter than the 60 minutes required by traditional manual analysis methods, thus providing data support for the rapid start-up of generator sets.

[0084] It should be noted that the high-pressure digestion system provided by this invention can provide higher dissolution temperatures and pressures, reducing the dissolution process of colloidal iron from approximately 1 hour to 3 minutes. The compound reaction reagent provided by this invention can simultaneously react with ferrous and ferric iron to generate the same complex product. The measurement process requires no additional redox reagents or a stringent pH colorimetric environment. Using this invention, rapid and accurate detection and analysis of total iron content in water samples is achieved, providing data support for the rapid start-up of similar units such as thermal power plants.

[0085] Other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and disclosure of the invention. This application is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of the invention are indicated by the following claims.

[0086] It should be understood that the present invention is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

[0087] The above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the present invention. Any simple modifications, alterations, or equivalent structural changes made to the above embodiments based on the technical essence of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A digestion system, characterized in that, The digestion system includes a digestion tank (3) and a digestion system housing (5). The digestion tank (3) is located inside the digestion system housing (5). A heater is installed on the outer wall of the digestion tank (3). An upper solenoid valve (1) and a lower solenoid valve (2) are installed on the outer wall of the digestion system housing (5). The upper end of the digestion tank (3) is connected to the upper solenoid valve (1), and the lower end of the digestion tank (3) is connected to the lower solenoid valve (2).

2. The digestion system according to claim 1, characterized in that, A cooling system (4) is provided on the outer wall of the digestion system shell (5).

3. A rapid detection system for total iron based on high-pressure digestion and complexation reaction, characterized in that, The system includes an acid addition module, a reaction system, a colorimetric system, a compound reagent dosing device, and the digestion system as described in claim 1. The outlet of the water sample pipeline to be tested and the outlet of the acid addition module are connected to the inlet of the digestion system. The outlet of the digestion system and the outlet of the compound reagent dosing device are connected to the inlet of the reaction system. The outlet of the reaction system is connected to the inlet of the colorimetric system.

4. The rapid detection system for total iron based on high-pressure digestion and complexation reaction according to claim 3, characterized in that, The compounding reaction agents include K4[Fe(CN)6] and K3[Fe(CN)6].

5. The rapid detection system for all iron based on high-pressure digestion and complexation reaction according to claim 4, characterized in that, The K4[Fe(CN)6] content in the compound reaction agent is 0.55 g / L.

6. The rapid detection system for all iron based on high-pressure digestion and coordination reaction according to claim 4, characterized in that, The content of K3[Fe(CN)6] in the compound reaction agent is 0.50 g / L.

7. The rapid detection system for total iron based on high-pressure digestion and coordination reaction according to claim 3, characterized in that, The reaction system is equipped with a temperature control device.

8. The rapid detection system for all iron based on high-pressure digestion and complexation reaction according to claim 3, characterized in that, The reaction system is equipped with a stirring device.

9. The rapid detection system for all iron based on high-pressure digestion and coordination reaction according to claim 3, characterized in that, A cooling system (4) is provided on the outer wall of the digestion system shell (5).

10. The rapid detection system for all iron based on high-pressure digestion and complexation reaction according to claim 3, characterized in that, The colorimetric system is based on spectrophotometry. The absorbance and color of the solution conform to Beer-Lambert law, which is used to calculate the total iron content of the water sample.

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