Visual colorimetric measuring device for trace iron in water vapor

Abstract

The utility model discloses a visual colorimetric measuring device for water vapor trace iron, which comprises a water inlet valve, a pressure gauge, a filter membrane holder, a water inlet pipe, an outer cylinder and an inner cylinder, the water inlet valve and the filter membrane holder are sequentially connected onto the water inlet pipe, the pressure gauge is further connected onto the water inlet pipe between the water inlet valve and the filter membrane holder, and the outer cylinder is connected with the inner cylinder. The outer cylinder and the inner cylinder are longitudinally distributed, openings of the outer cylinder and the inner cylinder face upwards, the inner cylinder is correspondingly arranged in the outer cylinder, and the water outlet end of the filter membrane holder corresponds to the opening of the inner cylinder. The device is convenient to operate and carry out, does not need to add chemical reagents, is convenient and fast, greatly shortens the analysis time, is low in analysis cost, is accurate and reliable in obtained analysis result, and can timely and effectively monitor the operation condition of the boiler.

Description

Technical Field

[0001] The utility model relates to a visual colorimetric measuring device for trace iron in water vapor. Background Art

[0002] The concentration of iron ions in the steam-water system of a power plant is one of the main monitoring indicators during the operation of the unit. A high concentration of iron ions may cause scaling or corrosion in the thermal system. Over time, it will lead to a decrease in the boiler operation efficiency and an increase in the operation cost. More seriously, it will cause the furnace wall to bulge and even explode.

[0003] Currently, there are several analysis methods for trace iron in the steam-water of power plants:

[0004] 1. Principle of atomic absorption method: Atomic absorption spectrometry is based on the fact that light radiated from a light source with a characteristic wavelength of the element to be measured passes through the atomic vapor and is absorbed by the ground-state atoms of the element to be measured in the vapor. According to Lambert-Beer's law, the absorbance is proportional to the concentration of the atoms of the element to be measured in the atomizer. Then, by using a standard solution to find the absorption coefficient, the content of the element to be measured can be calculated. The light source of the atomic absorption spectrometer is an iron hollow cathode lamp, the atomizer is a graphite furnace, the detector uses a photomultiplier tube, the purity of argon is >99.995%, the argon pressure is 0.4 MPa, an iron standard solution, and the resistivity of high-purity water is 18.2 MΩ·cm. This analysis uses more instrument components and is expensive.

[0005] 2. Principle of o-phenanthroline spectrophotometry: Ferrous ions react with o-phenanthroline (1,10-phenanthroline) under the condition of pH value 3-9 to form a stable orange-red complex ion. 3C 12 H8N2 + Fe 2+ → [Fe(C 12 H8N2)3] 2+ , and this complex ion is the most stable at pH value 3-4.5. Ferric ions in water are reduced to ferrous ions by hydroxylamine hydrochloride, and then the total iron can be measured. According to Lambert-Beer's law, the absorbance is proportional to the concentration of the complex, and by using a standard solution to find the absorption coefficient, the content of iron ions can be calculated. This analysis uses many reagents, has a cumbersome operation, a long analysis time, and is applicable to the determination of the iron ion concentration in water ≥1 mg / L.

[0006] Through the systematic corrosion investigation and the supervision of the total iron ion concentration, it is a comprehensive inspection test of the iron ion concentration in various steam and water of the power plant and various items related to iron. It is to find out the distribution of corrosion products in the system, understand the reasons for their generation, and thus take effective measures to prevent and slow down the corrosion, scaling, and accumulation of sediments in the thermal system. Therefore, a rapid and accurate iron ion determination method is particularly important in chemical supervision. Content of the Utility Model

[0007] The main technical problem to be solved by the present utility model is to provide a visual colorimetric measuring device for trace iron in water vapor, which is convenient to operate, does not require the addition of chemical reagents, is convenient and fast, greatly shortens the analysis time, has a low analysis cost, and the obtained analysis results are accurate and reliable, and can effectively monitor the operation status of the boiler in a timely manner.

[0008] To solve the above technical problems, a technical solution adopted by the present utility model is: to provide a visual colorimetric measuring device for trace iron in water vapor, including a water inlet valve, a pressure gauge, a filter membrane holder, a water inlet pipe, an outer cylinder and an inner cylinder. The water inlet valve and the filter membrane holder are sequentially connected to the water inlet pipe. A pressure gauge is also connected to the water inlet pipe between the water inlet valve and the filter membrane holder. Both the outer cylinder and the inner cylinder are longitudinally distributed and have openings facing upwards. The inner cylinder is correspondingly arranged inside the outer cylinder. The water outlet end of the filter membrane holder is correspondingly arranged with the opening of the inner cylinder.

[0009] In a preferred embodiment of the present utility model, the water inlet valve includes a first water inlet valve and a second water inlet valve. The first water inlet valve and the second water inlet valve are arranged in parallel. The second water inlet valve is connected in series with the filter membrane holder. The first water inlet valve is a water inlet bypass valve, and the second water inlet valve is a water inlet pressure regulating valve.

[0010] In a preferred embodiment of the present utility model, the filter membrane holder includes a membrane box, an O-ring, a support plate and a compression bolt.

[0011] In a preferred embodiment of the present utility model, the membrane box is arranged in a cylindrical structure and has a concave cavity recessed at the bottom. An inlet hole communicating with the concave cavity is arranged at the longitudinal center of the membrane box. A first positioning groove with an annular recess is arranged at the bottom of the membrane box. The support plate is arranged in a funnel-shaped structure. A second positioning groove with an annular recess is arranged at the top of the support plate. O-rings are correspondingly arranged in the first positioning groove and the second positioning groove. The edges of the membrane box and the support plate are connected and fixed by a plurality of compression bolts distributed in a ring.

[0012] In a preferred embodiment of the present utility model, the specification of the outer cylinder is 5L, and the specification of the inner cylinder is 500mL.

[0013] The beneficial effects of the present utility model are: a visual colorimetric measuring device for trace iron in water vapor pointed out by the present utility model is convenient to operate, does not require the addition of chemical reagents, is convenient and fast, greatly shortens the analysis time, has a low analysis cost, and the obtained analysis results are accurate and reliable, and can effectively monitor the operation status of the boiler in a timely manner. Description of the Drawings

[0014] To more clearly illustrate the technical solutions in the embodiments of the present utility model, the following will briefly introduce the attached drawings required for the description of the embodiments. Obviously, the attached drawings in the following description are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other attached drawings can also be obtained based on these drawings, where:

[0015] Figure 1 It is a schematic structural diagram of a measuring device of a preferred embodiment of a visual colorimetric measuring device for trace iron in water vapor of the present utility model;

[0016] Figure 2 It is the distribution (percentage of particles) of the particle size of the steel corrosion product under static test conditions of another preferred embodiment of a visual colorimetric measuring device for trace iron in water vapor of the present utility model;

[0017] Figure 3 It is the relationship between the particle size distribution of the steel corrosion product and the temperature of another preferred embodiment of a visual colorimetric measuring device for trace iron in water vapor of the present utility model. Specific embodiments

[0018] The following will clearly and completely describe the technical solutions in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present utility model.

[0019] Please refer to Figure 1 As shown, the embodiments of the present utility model include:

[0020] A visual colorimetric measuring device for trace iron in water vapor, including a water inlet valve, a pressure gauge 3, a filter membrane holder, a water inlet pipe 4, an outer cylinder 5, and an inner cylinder 6.

[0021] Among them, the water inlet valve and the filter membrane holder are sequentially connected to the water inlet pipe 4.

[0022] The water inlet valve includes a first water inlet valve 1 and a second water inlet valve 2. The first water inlet valve 1 and the second water inlet valve 2 are arranged in parallel. The second water inlet valve 2 is connected in series with the filter membrane holder. The first water inlet valve 1 is a water inlet bypass valve for water inlet connection. The second water inlet valve 2 is a water inlet pressure regulating valve to ensure that the water sample entering the membrane box 8 has no air and the flowing water sample is stable, so as to ensure uniform coloring of the filter membrane 7 in the later stage.

[0023] A pressure gauge 3 is also connected to the water inlet pipe 4 between the water inlet valve and the filter membrane holder to ensure the required water output.

[0024] The filter membrane holder includes a membrane cartridge 8, an O-ring 9, a support plate 10, and a compression bolt 11.

[0025] The membrane cartridge 8 is arranged in a cylindrical structure and has a concave cavity 12 recessed at the bottom, which can provide a certain amount of water sample storage space. An inlet hole 13 communicating with the concave cavity 12 is provided at the longitudinal center of the membrane cartridge 8 to facilitate water inlet. The support plate 10 is arranged in a funnel-shaped structure to facilitate water outlet. A first positioning groove 14 with an annular recess is provided at the bottom of the membrane cartridge 8, and a second positioning groove 15 with an annular recess is provided at the top of the support plate 10. O-rings 9 are correspondingly arranged in the first positioning groove 14 and the second positioning groove 15 for sealing the water sample space between the membrane cartridge 8 and the support plate 10. The edges of the membrane cartridge 8 and the support plate 10 are connected and fixed by a plurality of compression bolts 11 distributed in a ring, which facilitates the loading and unloading of the membrane cartridge 8 and the support plate 10.

[0026] Both the outer cylinder 5 and the inner cylinder 6 are longitudinally distributed and have openings facing upwards. The inner cylinder 6 is correspondingly arranged inside the outer cylinder 5. The specification of the outer cylinder 5 is 5L. After repeated tests and comparison of different concentrations of filter membrane 7 deposits, the iron imprint intercepted by 5 liters of water sample is visually the most reasonable. The specification of the inner cylinder 6 is 500 mL to facilitate achieving a water output of 500 mL / min.

[0027] The water outlet end of the filter membrane holder is correspondingly arranged with the opening of the inner cylinder 6, and the water sample preferentially enters the inner cylinder 6 to facilitate the adjustment of the water output.

[0028] A method for visual colorimetric testing of trace iron in water vapor uses a visual colorimetric measuring device for trace iron in water vapor, and includes the following steps:

[0029] a. Connect at the position to be detected with the inlet bypass valve open.

[0030] b. Loosen the compression bolt 11 and remove the support plate 10. Note: When disassembling, hold the support plate 10 firmly to prevent the support plate 10 from falling to the ground and being damaged.

[0031] c. With the inlet bypass valve open, adjust the opening of the inlet pressure regulating valve to ensure a small amount of water inlet into the membrane cartridge 8.

[0032] d. Remove the O-ring 9, place the filter membrane 7 to be tested on the support plate 10 and wet the filter membrane 7, then press the O-ring 9 on the filter membrane 7, reinstall the support plate 10 and the membrane cartridge 8, and tighten them with the compression bolt 11 to an appropriate degree.

[0033] e. Feed water into the inner cylinder 6, adjust the opening of the inlet pressure regulating valve, close the inlet bypass valve, and adjust the pressure of the pressure gauge 3 to ensure a water output of 500 mL / min.

[0034] f. After the water volume to be filtered reaches the full load of water samples in the outer cylinder 5, open the inlet bypass valve, close the inlet pressure regulating valve, loosen the compression bolt 11, remove the support plate 10, and take out the filter membrane 7.

[0035] g. Place the filter membrane 7 flat on a clean filter paper, compare it with the standard colorimetric card, and obtain the value of the iron ion concentration.

[0036] The specification of the filter membrane 7 is 0.45μm. In the steam-water system of power plants, iron ions often exist in the form of ferric oxide and ferric hydroxide precipitates. The 0.45μm filter membrane 7 of this device can effectively intercept 95% of iron, and can accurately reflect the iron ion concentration in water.

[0037] The standard colorimetric card is set to levels 1 - 6, corresponding to the values of iron ion concentration as follows: ≤1.0μg / L, ≤2.0μg / L, ≤4.0μg / L, ≤8.0μg / L, ≤15.0μg / L, and ≤30.0μg / L. The standard color samples are made into a vivid form, and visual comparison can be carried out from two dimensions: the depth of color and the clarity of the gap pattern, making the data more accurate.

[0038] The measuring device is simple and portable, and can be independently measured in the steam-water sampling room of the power plant. During the entire measurement period, the flow fluctuation should not be too large. The measurement time is short, generally 10 minutes, and the iron ion concentration data can be obtained immediately.

[0039] In summary, a visual colorimetric measuring device for trace iron in steam-water pointed out by the present utility model is convenient to operate, does not require the addition of chemical reagents, is convenient and fast, greatly shortens the analysis time, has a low analysis cost, the obtained analysis results are accurate and reliable, and can effectively monitor the operation status of the boiler in a timely manner.

[0040] The above are only the embodiments of the present utility model, and do not limit the patent scope of the present utility model accordingly. Any equivalent structure or equivalent process transformation made by using the content of the specification of the present utility model, or directly or indirectly applied in other related technical fields, shall be included in the patent protection scope of the present utility model by the same token.

Claims

1. A visual colorimetric measurement device for trace iron in water vapor, characterized in that: It includes an inlet valve, a pressure gauge, a filter membrane holder, an inlet pipe, an outer cylinder and an inner cylinder. The inlet valve and the filter membrane holder are sequentially connected to the inlet pipe. A pressure gauge is also connected to the inlet pipe between the inlet valve and the filter membrane holder. The outer cylinder and the inner cylinder are both longitudinally distributed and the openings are arranged upward. The inner cylinder is correspondingly arranged in the outer cylinder. The water outlet end of the filter membrane holder is arranged correspondingly to the opening of the inner cylinder.

2. The visual colorimetric measuring device for trace iron in water vapor according to claim 1, characterized in that: The water inlet valve includes a first water inlet valve and a second water inlet valve, the first water inlet valve and the second water inlet valve are arranged in parallel, the second water inlet valve and the membrane holder are arranged in series, the first water inlet valve is a water inlet bypass valve, and the second water inlet valve is a water inlet pressure regulating valve.

3. The visual colorimetric measurement device for trace iron in water vapor according to claim 1, characterized in that: The filter membrane holder comprises a membrane box, an O-ring, a support plate and a clamping bolt.

4. The visual colorimetric measurement device for trace iron in water vapor according to claim 3, characterized in that: The membrane box is arranged in a columnar structure and has a concave cavity at the bottom. A water inlet hole connected to the concave cavity is arranged in the longitudinal center of the membrane box. A first annular concave positioning groove is arranged at the bottom of the membrane box. The support plate is arranged in a funnel-shaped structure. A second annular concave positioning groove is arranged on the top of the support plate. O-rings are arranged in the first positioning groove and the second positioning groove respectively. The edges of the membrane box and the support plate are connected and fixed by multiple clamping bolts distributed in an annular manner.

5. The visual colorimetric measurement device for trace iron in water vapor according to claim 1, characterized in that: The specification of the outer cylinder is 5L, and the specification of the inner cylinder is 500mL.

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