Boiler protective agent for shutdown period and preparation method of boiler protective agent

Abstract

The invention relates to the technical field of boiler protection, and particularly provides a boiler protective agent in a shutdown period and a preparation method thereof, and the boiler protective agent comprises the following raw materials: polyamide wax, dimeticone, N, N-diethylhydroxylamine, tannin, span 80 and superfine silver powder. According to the boiler protective agent in the shutdown period and the preparation method thereof, the inner layer and the outer layer are combined, the effect of uniform water and oxygen corrosion resistance is achieved, and the weight of a boiler corroded is reduced.

Description

Technical Field

[0001] This invention relates to the field of boiler protection technology, and in particular to a boiler protection agent for use during downtime and its preparation method. Background Technology

[0002] Boilers are the heart of industry and high-value fixed assets. Post-operation maintenance is crucial; in numerous real-world cases, corrosion during boiler downtime is more severe than during operation. Severe, large-scale damage caused by boiler perforation corrosion often occurs not during operation, but during downtime.

[0003] For most boilers that have been out of use for a long time, calcium chloride and quicklime are added to the bottom of the boiler to absorb water and remove oxygen in order to avoid water vapor and oxidation corrosion. However, this crude treatment method is extremely uneven in the adsorption and removal of water and oxygen, and it is difficult to remove water and oxygen from the upper part of the boiler and deep in the complex structure. On the other hand, excessive adsorption at the bottom of the boiler will accumulate water and oxygen and accelerate corrosion.

[0004] Therefore, it is necessary to develop a boiler protection agent that is uniformly resistant to water and oxygen corrosion during the shutdown period, so as to reduce the weight loss of the boiler due to corrosion. Summary of the Invention

[0005] To address the aforementioned problems, the present invention aims to provide a boiler protection agent for use during shutdown and its preparation method. On one hand, the present invention provides a method for preparing a boiler protection agent for use during shutdown, wherein the method for preparing the boiler protection agent for use during shutdown is as follows: Step 1: Prepare N,N-diethylhydroxylamine (6-13% by mass), tannin (1.5-4% by mass), Span 80 (0.5-1.5% by mass), polyamide wax (1-3% by mass), and dimethicone oil to make up the balance; under nitrogen atmosphere, place the polyamide wax and dimethicone oil into an ultrasonic mixer with 1000-2000W power and 20KHz ultrasonic assistance at 1500-3000r / min and 75-85℃ and stir for 20min. After cooling to 50℃, add Span 80 and continue stirring for 15min. Then cool to 25℃, add the N,N-diethylhydroxylamine and tannin and continue stirring for 10min to obtain component A; Step 2: Under nitrogen atmosphere at 25℃, put 3-6% by mass of silver powder with a particle size of 10,000-50,000 mesh and make up the balance of dimethicone into an ultrasonic mixer with a power of 1000-2000W and an ultrasonic frequency of 20KHz, and stir for 1500-3000r / min for 30min to obtain component B. Step 3: Seal the component A (30-45% by mass) and the component B (to make up the balance) separately to obtain the boiler protection agent for the off-duty period.

[0006] Furthermore, the mass fraction of the N,N-diethylhydroxylamine is 9%.

[0007] Furthermore, the tannin has a mass fraction of 2.5%.

[0008] Furthermore, the mass fraction of the Span 80 is 1%.

[0009] Furthermore, the polyamide wax has a mass fraction of 2.2%.

[0010] Furthermore, the mass fraction of the silver powder is 4.5%.

[0011] Furthermore, the silver powder has a mesh size of 50,000.

[0012] Furthermore, the mass fraction of component A is 41%.

[0013] Furthermore, the ultrasonic power in step one is 2000W, and the stirring speed is 2300r / min.

[0014] Furthermore, the first stirring temperature in step one is 80°C.

[0015] Furthermore, the ultrasonic power in step two is 1000W, and the stirring speed is 2000r / min.

[0016] On the other hand, the present invention provides a boiler protection agent for use during the shutdown period prepared by the method described in any of the above claims.

[0017] The present invention may bring the following beneficial effects: The boiler protection agent for off-season and its preparation method of the present invention form a relatively dense network structure in component A, polyamide wax and dimethyl silicone oil, which can better accommodate N,N-diethylhydroxylamine and tannins. Span 80 improves dispersibility and stabilizes the system. After use, a metal-tannin-N,N-diethylhydroxylamine complex antioxidant layer is formed in the inner layer. In component B, ultrafine silver powder is dispersed in dimethyl silicone oil. After use, a closed oxygen-barrier anti-corrosion layer is formed in the outer layer. The combination of the inner and outer layers achieves the uniform anti-water and oxygen corrosion effect of the present invention, reducing the weight of the boiler due to corrosion. Detailed Implementation

[0018] To more clearly illustrate the overall concept of the present invention, the overall solution of the present invention will be described in detail below by way of embodiments; in the following description, numerous specific details are set forth in order to provide a more thorough understanding of the present invention; however, it will be apparent to those skilled in the art that the present invention may be practiced without one or more of these details; in other instances, some technical features known in the art have not been described in order to avoid confusion with the present invention.

[0019] In this invention, N,N-diethylhydroxylamine CAS number: 3710-84-7; tannin CAS number: 1401-55-4; Span 80 is Zopo S-80; polyamide wax is purchased from Shandong Honghe Chemical Co., Ltd., model DYD-9812; dimethicone oil CAS number 9006-65-9, Hongyao 12500 viscosity type (25℃); ultrasonic mixer is purchased from Hangzhou Gonglu Ultrasonic Equipment Co., Ltd., 10L type, 10L per batch; silver powder is ultrafine silver powder from Nangong Rongbang New Material Technology Co., Ltd. Except for the parameters explicitly stated as changed, all other parameters remain unchanged in the preparation steps.

[0020] Unless otherwise specified, all raw material components in the following examples are commercially available, all experimental instruments used are standard laboratory instruments, and the performance testing methods are those known in the art. The overall operating environment was 25°C and 30% humidity.

[0021] The preferred implementation method is as follows: Example 1: The boiler protection agent for the off-season is prepared using the following method: Step 1: Prepare 9% N,N-diethylhydroxylamine, 2.5% tannin, 1% Span 80, 2.2% polyamide wax, and make up the balance with dimethyl silicone oil; under nitrogen atmosphere, place the polyamide wax and dimethyl silicone oil into an ultrasonic mixer with a power of 2000W, 20KHz ultrasonic assistance, 2300r / min, and 80℃, and stir for 20min. After cooling to 50℃, add the Span 80 and continue stirring for 15min. Then cool to 25℃, add the N,N-diethylhydroxylamine and the tannin, and continue stirring for 10min to obtain component A; Step 2: Under nitrogen atmosphere at 25℃, silver powder with a mass fraction of 4.5% and a particle size of 50,000 mesh and dimethicone oil to make up the balance are put into an ultrasonic mixer with a power of 1000W, a power of 20KHz, and an ultrasonic auxiliary speed of 2000r / min for 30min to obtain component B. Step 3: Seal the 41% mass fraction of component A and the remaining component B separately to obtain the boiler protection agent for the off-duty period.

[0022] Examples 2-13: The only difference between Example 2 and Example 1 is that the mass fraction of N,N-diethylhydroxylamine is 6%; The only difference between Example 3 and Example 1 is that the mass fraction of N,N-diethylhydroxylamine is 13%. The only difference between Example 4 and Example 1 is that the tannin mass fraction is 1.5%; The only difference between Example 5 and Example 1 is that the tannin content is 4% by mass. The only difference between Example 6 and Example 1 is that the mass fraction of Span 80 is 0.5%; The only difference between Example 7 and Example 1 is that the mass fraction of Span 80 is 1.5%; The only difference between Example 8 and Example 1 is that the mass fraction of polyamide wax is 1%. The only difference between Example 9 and Example 1 is that the mass fraction of polyamide wax is 3%. The only difference between Example 10 and Example 1 is that the mass fraction of silver powder is 3%. The only difference between Example 11 and Example 1 is that the mass fraction of silver powder is 6%. The only difference between Example 12 and Example 1 is that the mass fraction of component A is 30%. The only difference between Example 13 and Example 1 is that the mass fraction of component A is 45%.

[0023] Comparative Examples 1-23: The only difference between Comparative Example 1 and Example 1 is that the mass fraction of N,N-diethylhydroxylamine is 3%; The only difference between Comparative Example 2 and Example 1 is that the mass fraction of N,N-diethylhydroxylamine is 25%. The only difference between Comparative Example 3 and Example 1 is that the tannin mass fraction is 0.5%; The only difference between Comparative Example 4 and Example 1 is that the tannin mass fraction is 10%; The only difference between Comparative Example 5 and Example 1 is that the mass fraction of Span 80 is 0.1%; The only difference between Comparative Example 6 and Example 1 is that the mass fraction of Span 80 is 4%; The only difference between Comparative Example 7 and Example 1 is that the mass fraction of polyamide wax is 0.3%; The only difference between Comparative Example 8 and Example 1 is that the mass fraction of polyamide wax is 6%; The only difference between Comparative Example 9 and Example 1 is that the mass fraction of silver powder is 1%. The only difference between Comparative Example 10 and Example 1 is that the mass fraction of silver powder is 12%. The only difference between Comparative Example 11 and Example 1 is that the mass fraction of component A is 10%. The only difference between Comparative Example 12 and Example 1 is that the mass fraction of component A is 70%. The only difference between Comparative Example 13 and Example 1 is that the ultrasonic power in step one is 2000W and the stirring speed is 2300r / min. The only difference between Comparative Example 14 and Example 1 is that the ultrasonic power in step one is 2000W and the stirring speed is 2300r / min. The only difference between Comparative Example 15 and Example 1 is that the ultrasonic power in step two is 1000W and the stirring speed is 2000r / min. The only difference between Comparative Example 16 and Example 1 is that the ultrasonic power in step two is 1000W and the stirring speed is 2000r / min. The only difference between Comparative Example 17 and Example 1 is that the first stirring temperature in step one is 100°C. The only difference between Comparative Example 18 and Example 1 is that the silver powder has a mesh size of 10,000. The only difference between Comparative Example 19 and Example 1 is that the mass fraction of N,N-diethylhydroxylamine is reduced to zero, while the proportions of other components remain unchanged; The only difference between Comparative Example 20 and Example 1 is that the mass fraction of tannin is reduced to zero, while the proportions of other components remain unchanged; The only difference between Comparative Example 21 and Example 1 is that the mass fraction of Span 80 is reduced to zero, while the proportions of other components remain unchanged; The only difference between Comparative Example 22 and Example 1 is that the mass fraction of polyamide wax is reduced to zero, while the proportions of other components remain unchanged; The only difference between Comparative Example 23 and Example 1 is that the boiler protectant during the shutdown period was replaced with an equal mass of dimethicone oil, which served as a control.

[0024] Prepare and weigh clean steel plates of type SA-210C with dimensions of 0.5cm × 25cm × 10cm. The quantity should be three times the total number of samples. Perform three repeated tests for each sample, using three steel plates. Each steel plate should be weighed at 0.8g / cm³. 2 The total coating amount was applied to the surface, A was applied and dried, then B was applied and dried. After standing for 72 hours, the samples were ready for testing. A sealed room with an air oxygen content of 25% and a temperature of 50℃ was prepared. Pure water with dissolved oxygen of 500μg / L was used to maintain a relative humidity of 85%. The steel plates to be tested were suspended in the room. After 90 days of testing, the steel plates were taken out, washed, dried, weighed, and the mass reduction of the steel plates was calculated as the water and oxygen corrosion resistance effect, in mg. The results were taken as the average of three tests and retained to one decimal place. The test results are shown in Table 1.

[0025] Table 1: Corrosion resistance test results for each example:

[0026] As can be seen from the data in Table 1, compared with other examples, the boiler protection agent and its preparation method during the shutdown period of the present invention, especially the scheme of Example 1 of the present invention, have a greater reduction in boiler weight due to corrosion; that is, the boiler protection agent and its preparation method during the shutdown period of the present invention, especially Example 1 of the present invention, can achieve better resistance to water and oxygen corrosion.

[0027] The above description is merely an embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of the present invention should be included within the scope of the claims of the present invention.

Claims

1. A method for preparing a boiler protective agent during shutdown, characterized in that, The preparation method of the boiler protection agent during the shutdown period is as follows: Step 1: Prepare N,N-diethylhydroxylamine (6-13% by mass), tannin (1.5-4% by mass), Span 80 (0.5-1.5% by mass), polyamide wax (1-3% by mass), and dimethicone oil to make up the balance; under nitrogen atmosphere, place the polyamide wax and dimethicone oil into an ultrasonic mixer with 1000-2000W power and 20KHz ultrasonic assistance at 1500-3000r / min and 75-85℃ and stir for 20min. After cooling to 50℃, add Span 80 and continue stirring for 15min. Then cool to 25℃, add the N,N-diethylhydroxylamine and tannin and continue stirring for 10min to obtain component A; Step 2: Under nitrogen atmosphere at 25℃, put 3-6% by mass of silver powder with a particle size of 10,000-50,000 mesh and make up the balance of dimethicone into an ultrasonic mixer with a power of 1000-2000W and an ultrasonic frequency of 20KHz, and stir for 1500-3000r / min for 30min to obtain component B. Step 3: Seal the component A (30-45% by mass) and the component B (to make up the balance) separately to obtain the boiler protection agent for the off-duty period.

2. The method for preparing the boiler protection agent during the shutdown period according to claim 1, characterized in that, The mass fraction of the N,N-diethylhydroxylamine is 9%.

3. The method for preparing the boiler protection agent during the shutdown period according to claim 1, characterized in that, The tannin has a mass fraction of 2.5%.

4. The method for preparing the boiler protection agent during the shutdown period according to claim 1, characterized in that, The mass fraction of the Span 80 is 1%.

5. The method for preparing the boiler protection agent during the shutdown period according to claim 1, characterized in that, The polyamide wax has a mass fraction of 2.2%.

6. The method for preparing the boiler protection agent during the shutdown period according to claim 1, characterized in that, The silver powder has a mass fraction of 4.5%.

7. The method for preparing the boiler protection agent during the shutdown period according to claim 1, characterized in that, The silver powder has a mesh size of 50,000.

8. The method for preparing the boiler protection agent during the shutdown period according to claim 1, characterized in that, The mass fraction of component A is 41%.

9. The method for preparing the boiler protection agent during the shutdown period according to claim 1, characterized in that, The ultrasonic power in step one is 2000W, and the stirring speed is 2300r / min.

10. The method for preparing the boiler protection agent during the shutdown period according to claim 1, characterized in that, The first stirring temperature in step one is 80℃.

11. The method for preparing the boiler protection agent during the shutdown period according to claim 1, characterized in that, The ultrasonic power in step two is 1000W, and the stirring speed is 2000r / min.

12. A boiler protection agent for shutdown period prepared by the method of preparing the boiler protection agent for shutdown period as described in any one of claims 1 to 11.

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