CN108020546B - Quality tester for chemical cleaning passivation film, testing solution and using method - Google Patents

Abstract

A chemical cleaning passivation film quality tester, a test solution and a use method thereof belong to the technical field of industrial instruments, and particularly relates to a chemical cleaning passivation film tester. The present invention includes a droplet system, a nitrogen sealing and purging system, a color identification and comparison system, a light source system, a data acquisition system, and a display and storage system. The invention is used to identify the quality inspection of chemical cleaning passivation films of various iron-containing condensers, heat exchangers, boiler heating surfaces, chemical equipment and other equipment, and can also be used to inspect the uniformity of the metal coating on the inner surface of the metal.

Description

A kind of chemical cleaning passivation film quality tester, test solution and use method

technical field

The invention belongs to the technical field of industrial instruments, in particular to a chemical cleaning passivation film tester.

Background technique

Due to the leakage and seepage of cooling equipment, raw water enters thermal equipment without treatment, and due to economic constraints, the water for thermal equipment contains trace impurities, etc. Therefore, thermal equipment in electric power, chemical, thermal and other industries will form during operation. Sediments (carbonate scale, silicate scale, sulfate scale, grease, etc.) and metal oxide corrosion products, the deposits and corrosion products on the heating surface will rapidly solidify under high temperature and high pressure conditions, forming a Additional layers of different thicknesses. This kind of additional layer will not only hinder the heat transfer, increase the fuel cost, and cause safety production accidents due to overheating and overheating of the local metal on the heating surface, but also aggravate the corrosion of the metal at the deposition site, which will eventually lead to serious economic losses. The matrix is very different, and it may also cause the metal to bear a large additional stress, and the stress will also aggravate the galvanic corrosion of the metal. Therefore, all enterprises attach great importance to it, and will regularly inspect and chemically clean the heating surface to eliminate deposits and ensure the cleanliness of the metal interior.

Therefore, the "Quality Standards for Chemical Cleaning of Industrial Equipment" (HG/T2387) and "Guidelines for Chemical Cleaning of Thermal Power Plant Boilers" (DL/T 794) ensure the long-term safety, economy, temperature, Environmental protection operation plays an important role, therefore, guiding the cleaning of thermal equipment has achieved important economic and social benefits.

The "Quality Standard for Chemical Cleaning of Industrial Equipment" (HG/T2387-2007) describes the quality inspection of the passive film and gives the method and standard value, but the color development (discoloration) reaction relies on human subjective judgment and artificial titration experiments. The results are often much higher than the standard qualified value (5 seconds is qualified or 8 blue dots.), therefore, it loses its guiding significance and practical effect. Therefore, the "Guidelines for Chemical Cleaning of Thermal Power Plant Boilers" with higher technical requirements ( DL/T 794), the inspection requirements for the passivation film are only: after cleaning, the metal surface forms a good passivation protective film. The reasons for the large errors in the quality inspection of the passivation film in HG/T2387 are: 1) The quality inspection structure is greatly affected by human subjective consciousness; 2) The sensory difference of people on the standard color; 3) Due to other factors, such as organic matter, etc. , resulting in a series of chemical reactions between the titrant and the metal surface, and a delay in the color reaction, resulting in larger results. For these three reasons, the quality inspection method of passivation film in HG/T2387 needs to be further improved and perfected. Therefore, there is an urgent need for a new technical solution in the prior art to solve this problem.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is: to provide a chemical cleaning passivation film quality tester, which is used to identify the chemical cleaning passivation of various iron-containing condensers, heat exchangers, boiler heating surfaces, chemical equipment and other equipment. The quality inspection of chemical film can also be used to inspect the uniformity of metal coating on the inner surface of metal.

A chemical cleaning passivation film quality tester, including a droplet system, a nitrogen sealing and purging system, a color identification and comparison system, a light source system, a data acquisition system, and a display and storage system;

The droplet system includes a sealed titration liquid pool, a titration needle, a needle-shaped solenoid valve, a titration pipeline and a timer 11;

The nitrogen sealing and purging system includes a highly elastic nitrogen storage bag and a nitrogen pipeline, which are used for purging the liquid drop pipeline and the titration needle and replacing and sealing the titration liquid pool to ensure that the titrant does not deteriorate;

The color identification and comparison system is used to monitor the color change of the droplet, and automatically compare it with the standard color, and send a signal when the end color is reached;

The light source system includes a standard color module and a signal amplifier output device. In the carbon steel inspection mode: the fluorescent lamp with the emission wavelength of 450-700nm is activated; in the stainless steel inspection mode: the fluorescent lamp with the emission wavelength of 450-595nm is activated;

The data acquisition system collects the electrical signals sent by the color contrast system, processes and outputs the data, and displays it on the display screen 61;

The display and storage system includes a display screen and a memory card.

Further, the tester also includes a metal frame and four bases.

Further, the specification of the titration needle is 1 drop of 0.1 ml, and the inner diameter of the titration pipeline is 0.15 mm.

Still further, the specification of the timer is a range of 0-1000s and an accuracy of 0.1s.

Still further, the standard color module stores standard color wavelengths of red, yellow-green, yellow, blue, and dark blue.

A carbon steel film quality test solution used in a chemical cleaning passivation film quality tester is configured as follows: 4.1-5.3g analytically pure copper sulfate pentahydrate, 3.5g analytically pure sodium chloride, 2mL of corrosion inhibitor IS- 129. 0.2mL analytically pure 0.1mol/L hydrochloric acid, 0.5mL analytically pure 70% formic acid, 0.2mL analytically pure phenolphthalein, 0.1g analytically pure sodium dodecylsulfonate, 0.1g analytically pure lauric acid, 0.1～0.2mL70 % medical alcohol solution, diluted to 100mL with first-class laboratory water.

A stainless steel film quality test solution used in a chemical cleaning passivation film quality tester is configured as follows: 4.6-5.2g analytically pure K ₃ [Fe(CN) ₆ ], 3.5g analytically pure sodium chloride, 1 mL analytically pure K 3 [Fe(CN) 6 ] Pure 36% hydrochloric acid; 0.5mL0.5mol/L analytically pure sodium glycine, 0.1g analytically pure sodium dodecylsulfonate, 0.2mL1% analytically pure phenolphthalein, 2mL corrosion inhibitor XD-255, 0.2g analytically pure lauric acid , 0.1mL of 70% medical alcohol solution, 0.2mL of analytically pure 98% sulfuric acid, 1mL of analytically pure 70% formic acid, diluted to 100mL with distilled water.

A method of using a chemical cleaning passivation film quality tester, characterized in that it comprises the following steps:

Step 1. Fix the chemical cleaning passivation film quality tester on the metal surface, and select carbon steel mode or stainless steel mode as required;

Step 2, the chemical cleaning passivation film quality tester automatically selects 5 points on the metal surface, and drips the solution on each point;

Step 3, the chemical cleaning passivation film quality tester automatically records the time from the first drop of titration to the time when the solution changes from blue or yellow-green to red or blue, and automatically compares the droplet color with the standard color;

In the carbon steel mode, the quality of the film is checked by the time when the droplet changes from blue to red completely. When the blue color of each point disappears and the time for all the points to change to red is more than 5s, it is qualified, and the evaluation is automatically based on the relationship between the discoloration time of each point. Integrity and uniformity of passivation film quality. After the test is completed, the pipeline and titration needle are automatically purged with nitrogen;

In the stainless steel mode, when the number of small blue dots in yellow-green droplets within 10 minutes at each point is not less than 8, it is qualified. The integrity and uniformity of the passivation film quality were evaluated according to the number of small blue dots in the yellow-green droplets within 10 minutes of each point. After the test is completed, the tubing and titration needle are automatically purged with nitrogen.

Through the above-mentioned design scheme, the present invention can bring the following beneficial effects: the passive film, the exposed metal matrix after being destroyed reacts with blue copper sulfate solution and yellow potassium ferricyanide solution respectively to form red elemental copper (blue Turn red) or blue Fe3[Fe(CN)6]2 (yellow with blue dots), according to the length of discoloration time (the number of blue dots in yellow-green droplets within 10 minutes) to check the quality of the passivation film , relying on the discoloration time difference and the difference in the number of blue dots, automatically check the quality integrity and uniformity of the passivation film according to the program.

Description of drawings

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments:

FIG. 1 is a schematic structural diagram of a chemical cleaning passivation film quality tester according to the present invention.

FIG. 2 is a schematic top view of a chemical cleaning passivation film quality tester according to the present invention.

FIG. 3 is a schematic bottom view of a chemical cleaning passivation film quality tester according to the present invention.

4 is a cross-sectional view of a chemical cleaning passivation film quality tester according to the present invention.

In the figure, 1-droplet system, 2-nitrogen sealing and purging system, 3-color identification and comparison system, 4-light source system, 5-data acquisition system, 6-display and storage system, 11-timer, 61- display.

Detailed ways

A chemical cleaning passivation film quality tester, as shown in Figure 1-4, includes a droplet system 1, a nitrogen sealing and purging system 2, a color identification and comparison system 3, a light source system 4, a data acquisition system 5, and a display and storage system 6;

The droplet system 1 includes a sealed titration pool, a titration needle, a needle-shaped solenoid valve, a titration pipeline and a timer 11;

The nitrogen sealing and purging system 2 includes a highly elastic nitrogen storage bag and a nitrogen pipeline, which are used for purging the liquid drop pipeline and the titration needle and replacing and sealing the titration liquid pool to ensure that the titrant does not deteriorate;

The color identification and comparison system 3 is used to monitor the color change of the droplet, and automatically compare it with the standard color, and send a signal when the end color is reached;

The light source system 4 includes a standard color module and a signal amplifying output device. In the carbon steel inspection mode: the fluorescent lamp with the emission wavelength of 450-700 nm is activated; in the stainless steel inspection mode: the fluorescent lamp with the emission wavelength of 450-595 nm is activated;

The data acquisition system 5 collects the electrical signals sent by the color contrast system, processes and outputs the data, and displays it on the display screen 61;

The display and storage system 6 includes a display screen 61 and a memory card.

The tester also includes a metal frame 7 and four bases.

The specification of the titration needle is 1 drop of 0.1 ml, and the inner diameter of the titration tube is 0.15 mm.

The specification of the timer 11 is a range of 0-1000s and an accuracy of 0.1s.

The standard color module stores standard color wavelengths of red, yellow-green, yellow, blue, and dark blue.

A carbon steel film quality test solution used in a chemical cleaning passivation film quality tester is configured as follows: 4.1-5.3g analytically pure copper sulfate pentahydrate, 3.5g analytically pure sodium chloride, 2mL of corrosion inhibitor IS- 129. 0.2mL analytically pure 0.1mol/L hydrochloric acid, 0.5mL analytically pure 70% formic acid, 0.2mL analytically pure phenolphthalein, 0.1g analytically pure sodium dodecylsulfonate, 0.1g analytically pure lauric acid, 0.1～0.2mL70 % medical alcohol solution, diluted to 100mL with first-class laboratory water.

A stainless steel film quality test solution used in a chemical cleaning passivation film quality tester is configured as follows: 4.6-5.2g analytically pure K ₃ [Fe(CN) ₆ ], 3.5g analytically pure sodium chloride, 1 mL analytically pure K 3 [Fe(CN) 6 ] Pure 36% hydrochloric acid; 0.5mL0.5mol/L analytically pure sodium glycine, 0.1g analytically pure sodium dodecylsulfonate, 0.2mL1% analytically pure phenolphthalein, 2mL corrosion inhibitor XD-255, 0.2g analytically pure lauric acid , 0.1mL of 70% medical alcohol solution, 0.2mL of analytically pure 98% sulfuric acid, 1mL of analytically pure 70% formic acid, diluted to 100mL with distilled water.

A method for using a chemical cleaning passivation film quality tester, comprising the following steps:

Step 1. Fix the chemical cleaning passivation film quality tester on the metal surface, and select carbon steel mode or stainless steel mode as required;

Step 2, the chemical cleaning passivation film quality tester automatically selects 5 points on the metal surface, and drips the solution on each point;

Step 3, the chemical cleaning passivation film quality tester automatically records the time from the first drop of titration to the change of the solution from blue or yellow-green to red or blue, and automatically compares the droplet color with the standard color;

In the carbon steel mode, the quality of the film is checked by the time when the droplet changes from blue to red completely. When the blue color of each point disappears and the time for all the points to change to red is more than 5s, it is qualified, and the evaluation is automatically based on the relationship between the discoloration time of each point. Integrity and uniformity of passivation film quality. After the test is completed, the pipeline and titration needle are automatically purged with nitrogen;

In the stainless steel mode, when the number of small blue dots in yellow-green droplets within 10 minutes at each point is not less than 8, it is qualified. The integrity and uniformity of the passivation film quality were evaluated according to the number of small blue dots in the yellow-green droplets within 10 minutes of each point. After the test is completed, the tubing and titration needle are automatically purged with nitrogen.

Example

Suitable for carbon steel film quality testing

The composition of the test solution is as follows: the mass fraction is a mixed solution of acidic copper sulfate + formic acid + alcohol. Preparation requirements: 4.1～5.3g analytically pure copper sulfate pentahydrate, 3.5g analytically pure sodium chloride, 2mL of corrosion inhibitor IS-129, 0.2mL of analytically pure 0.1mol/L hydrochloric acid, 0.5mL of analytically pure 70% formic acid, 0.2mL1 % analytically pure phenolphthalein, 0.1 g of analytically pure sodium dodecyl sulfonate, 0.1 g of analytically pure lauric acid, 0.1-0.2 mL of 70% medical alcohol solution, diluted to 100 mL with first-class experimental water).

Among them, sodium dodecyl sulfonate is a wetting agent to reduce the surface tension of droplets; the function of phenolphthalein is to eliminate the difference between the color of iron droplets and the standard color; medical alcohol eliminates the reaction and color development of metal adsorption proteins, oil, etc. Reaction delay phenomenon, lauric acid is used to alleviate the optical reaction of medicines and reduce the rate of deterioration of medicines.

Inspection method: display 5-point discoloration time (Sn).

Uniformity inspection basis: The average value of the root mean square of the 5-point discoloration time (Sn) is the benchmark (Sj), and the average of the 5-point discoloration time (Sn) is Ss.

When ︱Sj－Ss︱≤0.5, it means that the quality of the passivation film is very complete and uniform.

When 0.5≤︱Sj－Ss︱≤1, it means that the quality of the passivation film is complete and uniform.

When 1≤︱Sj－Ss︱≤1.5, it means that the quality of the passivation film is relatively complete and uniform.

When 1.5≤︱Sj－Ss︱≤2, it means that the quality of the passivation film is incomplete and uneven.

When ︱Sj－Ss︱＞3, it means that the quality of the passivation film is very incomplete and uneven.

Suitable for stainless steel film quality testing

The composition of the test solution is as follows: the mass fraction is a mixed solution of acidic potassium ferricyanide + formic acid + sodium glycine + phenolphthalein + alcohol. Preparation requirements: 4.6～5.2g analytically pure K ₃ 〖Fe(CN) ₆ 〗, 3.5g analytically pure sodium chloride, 1mL analytically pure 36% hydrochloric acid; 0.5mL0.5mol/L analytically pure sodium glycine, 0.1g analytically pure Sodium dodecyl sulfonate, 0.2mL of 1% analytical phenolphthalein, 2mL of corrosion inhibitor XD-255, 0.2g of analytically pure lauric acid, 0.1mL of 70% medical alcohol solution, 0.2mL of analytically pure 98% sulfuric acid, 1mL of analytically pure 70% Formic acid, diluted with distilled water to 100mL.

Among them, sodium dodecyl sulfonate is a wetting agent to reduce the surface tension of droplets; the function of sodium glycine is to shield the interference of ferric iron on the color reaction (yellow-green → blue dots); the function of phenolphthalein is to eliminate the The difference between the color of iron droplets and the standard color; medical alcohol is not only used to ensure the dissolution of phenolphthalein, but also to eliminate the delay phenomenon of metal adsorption protein, oil, etc. on spotting reaction and color reaction. Formic acid is a buffer solution of pH value. Acids are used to alleviate the optical reaction of pharmaceuticals and reduce the rate of deterioration of pharmaceuticals.

Inspection method: The number of blue dots that appear within 10 minutes of every 5 points.

Uniformity test basis: The root mean square average of the number of blue dots that appear within 5:00 and 10 minutes is the benchmark (Sj), and the average of the number of blue dots (Sn) that appears within 5:00 and 10 minutes is Ss.

When ︱Sj－Ss︱≤1, it means that the quality of the passivation film is very complete and uniform.

When 1≤︱Sj－Ss︱≤2, it means that the quality of the passivation film is complete and uniform.

When 2≤︱Sj－Ss︱≤3, it means that the quality of the passivation film is relatively complete and uniform.

When ︱Sj－Ss︱≥3, it means that the quality of the passivation film is incomplete and uneven.

When ︱Sj－Ss︱＞4, it means that the quality of the passivation film is very incomplete and uneven.

Claims (6)

1. A chemical cleaning passivation film quality tester, characterized in that it comprises a droplet system (1), a nitrogen sealing and purging system (2), a color identification and comparison system (3), a light source system (4), a data an acquisition system (5) and a display and storage system (6); The droplet system (1) includes a sealed titration liquid pool, a titration needle, a needle-shaped solenoid valve, a titration pipeline and a timer (11); The nitrogen sealing and purging system (2) includes a highly elastic nitrogen storage bag and a nitrogen pipeline, which are used for purging the droplet pipeline and the titration needle and replacing and sealing the titration liquid pool, so as to ensure that the titrant does not deteriorate; The color identification and comparison system (3) is used to monitor the color change of the droplet, automatically compare it with the standard color, and send a signal when the end color is reached; The light source system (4) includes a standard color module and a signal amplifying output device, in the carbon steel inspection mode: the fluorescent lamp with the emission wavelength of 450-700nm is activated; in the stainless steel inspection mode: the fluorescent lamp with the emission wavelength of 450-595nm is activated; The data acquisition system (5) collects the electrical signals sent by the color contrast system, processes and outputs the data, and displays it on the liquid crystal display; The display and storage system (6) includes a display screen (61) and a memory card; The titration solution is configured as follows when carbon steel film quality test solution is used: 4.1~5.3g analytically pure copper sulfate pentahydrate, 3.5g analytically pure sodium chloride, 2mL of corrosion inhibitor IS-129, 0.2mL of analytically pure 0.1mol/L Hydrochloric acid, 0.5mL analytically pure 70% formic acid, 0.2mL1% analytically pure phenolphthalein, 0.1g analytically pure sodium dodecyl sulfonate, 0.1g analytically pure lauric acid, 0.1-0.2mL of 70% medical alcohol solution, use first-grade experimental water Dilute to 100mL; The titration solution is configured as follows when using stainless steel membrane quality test solution: 4.6～5.2g analytically pure K ₃ [Fe(CN) ₆ ], 3.5g analytically pure sodium chloride, 1mL analytically pure 36% hydrochloric acid; 0.5mL0.5mol/ L analytically pure sodium glycine, 0.1 g analytically pure sodium dodecyl sulfonate, 0.2 mL of 1% analytically pure phenolphthalein, 2 mL of corrosion inhibitor XD-255, 0.2 g of analytically pure lauric acid, 0.1 mL of 70% medical alcohol solution, 0.2 mL Analytical grade 98% sulfuric acid, 1 mL analytical grade 70% formic acid, diluted to 100 mL with distilled water. 2. A chemical cleaning passivation film quality tester according to claim 1, characterized in that: the tester further comprises a metal frame (7) and four bases. 3. A chemical cleaning passivation film quality tester according to claim 1, characterized in that: the specification of the titration needle is 1 drop of 0.1ml, and the inner diameter of the titration pipeline is 0.15mm. 4. A chemical cleaning passivation film quality tester according to claim 1, characterized in that: the specification of the timer is a range of 0-1000s, and a precision of 0.1s. 5 . A chemical cleaning passivation film quality tester according to claim 1 , wherein the standard color module stores standard color wavelengths of red, yellow-green, yellow, blue, and dark blue. 6 . 6. the using method of a kind of chemical cleaning passivation film quality inspection instrument as claimed in claim 1 is characterized in that comprising the following steps: Step 1, a kind of chemical cleaning passivation film quality tester as claimed in claim 1 is fixed on the metal surface, and carbon steel mode or stainless steel mode is selected as required; Step 2, the described chemical cleaning passivation film quality tester automatically selects 5 points on the metal surface, and drips the solution on each point; Step 3. The chemical cleaning passivation film quality tester automatically records the time from the first drop of titration to the time when the solution changes from blue or yellow-green to red or blue, and automatically compares the droplet color with the standard color ; In the carbon steel mode, the quality of the film is checked by the time when the droplet changes from blue to red completely. When the blue color of each point disappears and the time for all the points to change to red is more than 5s, it is qualified, and the evaluation is automatically based on the relationship between the discoloration time of each point. The integrity and uniformity of the passivation film quality, after the test is completed, the pipeline and titration needle are automatically purged with nitrogen; In the stainless steel mode, when the number of blue dots on yellow-green droplets at each point is not less than 8 within 10 minutes, it is qualified. To ensure the integrity and uniformity of the film quality, after the test is completed, the pipeline and titration needle are automatically purged with nitrogen.

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