Scale remover

Abstract

The invention discloses an anti-scaling agent for an industrial boiler. Comprising the following components in parts by weight: 10-30 parts of organic acid, 5-15 parts of a chelating agent, 3-10 parts of a surfactant, 5-10 parts of a corrosion inhibitor, 3-5 parts of a dispersing agent, 5-10 parts of essence and 60-100 parts of water. According to the scale remover, strong acid or strong base is not adopted as a main agent, the scale remover is friendly to the environment and constructors and high in safety, the scale removing time is shortened through combined use of the sulfosalicylic acid and the L-glutamic acid-N, N-diacetic acid, the boric acid diglyceride and the rhamnolipid, and the scale removing efficiency is improved. Due to the combined use of-butyl-3-methylimidazolium tetrafluoroborate and sodium molybdate, the scale inhibition time is prolonged.

Description

Technical Field

[0001] This invention belongs to the field of descaling agent technology, specifically relating to a descaling agent for industrial boilers. Background Technology

[0002] Industrial boilers, as core equipment in thermal power generation, shipbuilding, locomotive manufacturing, and mining enterprises, inevitably face scale problems during long-term operation. These hard, dense, white solid deposits are mainly formed by the continuous evaporation and concentration of hardness components such as calcium and magnesium carbonates in the water under high temperature and pressure. When water is heated to its saturation temperature, calcium and magnesium carbonates exceeding their solubility precipitate out, with most adhering to the boiler walls and pipes, affecting heat transfer efficiency, while some settles at the bottom. Scale formation is a complex physicochemical process, with main components including calcium carbonate, magnesium carbonate, calcium sulfate, calcium silicate, and iron oxide. Differences in water quality in different regions can lead to variations in the composition of scale.

[0003] For existing scale buildup, industrial cleaning primarily employs two types of methods: chemical and physical. Chemical cleaning is a common approach, and its standard procedure includes: water rinsing, acid washing, alkaline washing, water rinsing, rinsing, and passivation. According to the "Boiler Chemical Cleaning Rules," when cleaning carbonate scale, the removal area should reach at least 80% of the original scale coverage area; when cleaning silicate or sulfate scale, the removal area should reach 60% of the original scale coverage area. Physical cleaning mainly utilizes high-pressure water jet technology, employing a 750 bar high-pressure cleaner to remove scale using the highly concentrated kinetic energy of the water jet.

[0004] High-pressure water jets possess extremely high energy; improper operation or equipment malfunction can cause serious injury or even death if the water penetrates the skin or strikes the body. Water jets can also splash scale or other debris at high speeds, injuring operators and surrounding equipment. Physical cleaning, especially mechanical descaling of large boilers, is a very slow and labor-intensive process, resulting in prolonged boiler downtime and severely impacting production. While the initial investment in equipment for a single cleaning session may be low, the overall cost can be very high considering the long labor hours, indirect losses from boiler downtime, and potential repair costs for permanent damage to the boiler. The large amounts of scale and wastewater removed during cleaning require proper disposal to prevent environmental pollution. Treating these wastes also requires additional costs and effort. Compared to physical cleaning, chemical cleaning (especially with strong acids and alkalis) can remove scale more thoroughly, but it introduces a series of complex and potentially more dangerous problems: strong acids, while intended to dissolve scale, can also react with the metal substrate (such as iron), causing corrosion of the equipment itself. Even with added corrosion inhibitors, there is a risk that the inhibitors may become ineffective or their effectiveness may decrease at high temperatures and concentrations, potentially causing thinning, pitting, or even perforation of the equipment. Certain acids (especially hydrochloric acid) can cause stress corrosion cracking in austenitic stainless steel. Hydrogen atoms produced by the reaction of acid with metal can penetrate the metal, leading to "hydrogen embrittlement," which reduces the metal's toughness and causes brittle fracture—an extremely dangerous hidden defect. Many metals (such as stainless steel and titanium) rely on a very thin but dense oxide film on their surface for corrosion protection. Strong acids and alkalis can easily destroy this film, putting the metal in an activated state. If proper passivation treatment is not performed after cleaning, the equipment will be highly susceptible to rapid corrosion in the initial stages of operation. Strong acids and alkalis are extremely corrosive; contact with skin or eyes can cause severe burns and even permanent damage. When cleaning scale, strong acids may react with certain scales (such as ferrous sulfide scale) to produce highly toxic hydrogen sulfide gas. Reacting with rust scale can release hydrogen gas, posing an explosion risk. These gases accumulate in confined spaces (such as inside a boiler), posing a deadly threat to human life. Acid or alkaline fumes generated during chemical preparation and cleaning processes can severely irritate and damage the respiratory tract if inhaled. Summary of the Invention

[0005] The purpose of this invention is to provide a descaling agent for industrial boilers.

[0006] A descaling agent comprising the following components in parts by weight: 10-30 parts organic acid, 5-15 parts chelating agent, 3-10 parts surfactant, 5-10 parts corrosion inhibitor, 3-5 parts dispersant, 5-10 parts fragrance, and 60-100 parts water.

[0007] The organic acid is one or more of citric acid, aminosulfonic acid, glycolic acid, sulfosalicylic acid, L-glutamic acid-N,N-diacetic acid, and gluconic acid.

[0008] The organic acid is a mixture of sulfosalicylic acid and L-glutamic acid-N,N-diacetic acid in a mass ratio of 1:3.

[0009] The chelating agent is one or more of the following: disodium ethylenediaminetetraacetate, diethylenetriaminepentaacetic acid, ethylene glycol diethyl ether diaminetetraacetic acid, and aminotrimethylenephosphonic acid.

[0010] The surfactant is a mixture of diglyceride borate and rhamnolipid in a mass ratio of 2:1.

[0011] The corrosion inhibitor is a mixture of 1-butyl-3-methylimidazolium tetrafluoroborate and sodium molybdate in a mass ratio of 1:1.

[0012] The dispersant is one or more of fatty alcohol polyoxyethylene ether, fatty alcohol polyoxyethylene ether phosphate, polyvinylpyrrolidone, and octyl glycoside.

[0013] The fragrance is one or more of the following: rose fragrance, lavender fragrance, vanilla fragrance, tuberose fragrance, jasmine fragrance, basil fragrance, frankincense fragrance, and anise fragrance.

[0014] The descaling agent is prepared according to the following steps: (1) Add water to a container, heat to 60-70℃, add organic acid, chelating agent and surfactant, and stir at 200-400 rpm for 3-5 minutes; (2) Cool down to 40-50℃, add corrosion inhibitor, dispersant and fragrance, and stir at 100-300 rpm for 5-10 minutes; (3) The mixed solution obtained in step (3) is kept under a vacuum of 0.04-0.08 MPa and a temperature of 50-60℃ for 40-60 min, and then naturally cooled to room temperature (25℃) to obtain a descaling agent.

[0015] Preferably, the vacuum degree in step (3) is 0.06 MPa.

[0016] The beneficial effects of this invention are as follows: The descaling agent of this invention does not use strong acids or strong alkalis as the main agents, making it environmentally friendly and safe for construction workers. The combined use of sulfosalicylic acid and L-glutamic acid-N,N-diacetic acid, as well as diglycerides of borate and rhamnolipids, shortens the scale removal time, while the combined use of butyl-3-methylimidazolium tetrafluoroborate and sodium molybdate prolongs the scale inhibition time. Detailed Implementation

[0017] To facilitate understanding of the present invention, a more comprehensive description will be given below. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the present invention. Example 1

[0018] A descaling agent comprising the following components in parts by weight: 5 parts sulfosalicylic acid, 15 parts L-glutamic acid-N,N-diacetic acid, 10 parts disodium ethylenediaminetetraacetate, 4 parts diglyceride borate, 2 parts rhamnolipid, 4 parts 1-butyl-3-methylimidazolium tetrafluoroborate, 4 parts sodium molybdate, 4 parts fatty alcohol polyoxyethylene ether, 7 parts rose fragrance, and 80 parts water.

[0019] The descaling agent is prepared according to the following steps: (1) Add water to a container, heat to 65°C, add sulfosalicylic acid, L-glutamic acid-N,N-diacetic acid, disodium ethylenediaminetetraacetate, diglyceride borate, and rhamnolipid, and stir at 300 rpm for 4 min. (2) Cool down to 45°C, add 1-butyl-3-methylimidazolium tetrafluoroborate, sodium molybdate, fatty alcohol polyoxyethylene ether, and rose fragrance, and stir at 200 rpm for 8 min; (3) The mixed solution obtained in step (3) is kept under a vacuum of 0.06 MPa and a temperature of 55°C for 50 min, and then naturally cooled to room temperature (25°C) to obtain a descaling agent. Example 2

[0020] A descaling agent comprising the following components in parts by weight: 6 parts citric acid, 6 parts aminosulfonic acid, 6 parts diethylenetriaminepentaacetic acid, 2 parts diglyceride borate, 2 parts rhamnolipid, 3 parts 1-butyl-3-methylimidazolium tetrafluoroborate, 3 parts sodium molybdate, 3 parts polyvinylpyrrolidone, 3 parts lavender fragrance, 3 parts tuberose fragrance, and 70 parts water.

[0021] The descaling agent is prepared according to the following steps: (1) Add water to a container, heat to 60°C, add citric acid, aminosulfonic acid, diethylenetriaminepentaacetic acid, diglyceride borate, and rhamnolipid, and stir at 200 rpm for 5 min; (2) Cool down to 40°C, add 1-butyl-3-methylimidazolium tetrafluoroborate, sodium molybdate, polyvinylpyrrolidone, 3 parts lavender fragrance, and 3 parts tuberose fragrance, and stir at 100 rpm for 6 min; (3) The mixed solution obtained in step (3) is kept under a vacuum of 0.04 MPa and a temperature of 50°C for 40 min, and then naturally cooled to room temperature (25°C) to obtain the descaling agent. Example 3

[0022] A descaling agent comprising the following components in parts by weight: 12 parts glycolic acid, 13 parts gluconic acid, 13 parts aminotrimethylenephosphonic acid, 6 parts diglyceride borate, 3 parts rhamnolipid, 4 parts 1-butyl-3-methylimidazolium tetrafluoroborate, 4 parts sodium molybdate, 5 parts octyl glycoside, 8 parts basil flavoring, and 90 parts water.

[0023] The descaling agent is prepared according to the following steps: (1) Add water to a container, heat to 70°C, add glycolic acid, gluconic acid, aminotrimethylene phosphonic acid, diglyceride borate, and rhamnolipid, and stir at 400 rpm for 5 min; (2) Cool down to 50°C, add 4 parts of 1-butyl-3-methylimidazolium tetrafluoroborate, 4 parts of sodium molybdate, 5 parts of octyl glycoside and basil flavor, and stir at 300 rpm for 10 min; (3) The mixed solution obtained in step (3) is kept under a vacuum of 0.08 MPa and a temperature of 60°C for 60 min, and then naturally cooled to room temperature (25°C) to obtain a descaling agent.

[0024] Comparative Example 1 A descaling agent comprising the following components in parts by weight: 20 parts sulfosalicylic acid, 10 parts disodium ethylenediaminetetraacetate, 4 parts diglyceride borate, 2 parts rhamnolipid, 4 parts 1-butyl-3-methylimidazolium tetrafluoroborate, 4 parts sodium molybdate, 4 parts fatty alcohol polyoxyethylene ether, 7 parts rose fragrance, and 80 parts water.

[0025] The descaling agent is prepared according to the following steps: (1) Add water to a container, heat to 65°C, add sulfosalicylic acid, disodium ethylenediaminetetraacetate, diglyceride borate, and rhamnolipid, and stir at 300 rpm for 4 min; (2) Cool down to 45°C, add 1-butyl-3-methylimidazolium tetrafluoroborate, sodium molybdate, fatty alcohol polyoxyethylene ether, and rose fragrance, and stir at 200 rpm for 8 min; (3) The mixed solution obtained in step (3) is kept under a vacuum of 0.06 MPa and a temperature of 55°C for 50 min, and then naturally cooled to room temperature (25°C) to obtain a descaling agent.

[0026] Comparative Example 2 A descaling agent comprising the following components in parts by weight: 20 parts L-glutamic acid-N,N-diacetic acid, 10 parts disodium ethylenediaminetetraacetate, 4 parts diglyceride borate, 2 parts rhamnolipid, 4 parts 1-butyl-3-methylimidazolium tetrafluoroborate, 4 parts sodium molybdate, 4 parts fatty alcohol polyoxyethylene ether, 7 parts rose fragrance, and 80 parts water.

[0027] The descaling agent is prepared according to the following steps: (1) Add water to a container, heat to 65°C, add L-glutamic acid-N,N-diacetic acid, disodium ethylenediaminetetraacetate, diglyceride borate, and rhamnolipid, and stir at 300 rpm for 4 min; (2) Cool down to 45°C, add 1-butyl-3-methylimidazolium tetrafluoroborate, sodium molybdate, fatty alcohol polyoxyethylene ether, and rose fragrance, and stir at 200 rpm for 8 min; (3) The mixed solution obtained in step (3) is kept under a vacuum of 0.06 MPa and a temperature of 55°C for 50 min, and then naturally cooled to room temperature (25°C) to obtain a descaling agent.

[0028] Comparative Example 3 A descaling agent comprising the following components in parts by weight: 5 parts sulfosalicylic acid, 15 parts L-glutamic acid-N,N-diacetic acid, 10 parts disodium ethylenediaminetetraacetate, 6 parts diglyceride borate, 4 parts 1-butyl-3-methylimidazolium tetrafluoroborate, 4 parts sodium molybdate, 4 parts fatty alcohol polyoxyethylene ether, 7 parts rose fragrance, and 80 parts water.

[0029] The descaling agent is prepared according to the following steps: (1) Add water to a container, heat to 65°C, add sulfosalicylic acid, L-glutamic acid-N,N-diacetic acid, disodium ethylenediaminetetraacetate, and diglyceride borate, and stir at 300 rpm for 4 min; (2) Cool down to 45°C, add 1-butyl-3-methylimidazolium tetrafluoroborate, sodium molybdate, fatty alcohol polyoxyethylene ether, and rose fragrance, and stir at 200 rpm for 8 min; (3) The mixed solution obtained in step (3) is kept under a vacuum of 0.06 MPa and a temperature of 55°C for 50 min, and then naturally cooled to room temperature (25°C) to obtain a descaling agent.

[0030] Comparative Example 4 A descaling agent comprising the following components in parts by weight: 5 parts sulfosalicylic acid, 15 parts L-glutamic acid-N,N-diacetic acid, 10 parts disodium ethylenediaminetetraacetate, 6 parts rhamnolipid, 4 parts 1-butyl-3-methylimidazolium tetrafluoroborate, 4 parts sodium molybdate, 4 parts fatty alcohol polyoxyethylene ether, 7 parts rose fragrance, and 80 parts water.

[0031] The descaling agent is prepared according to the following steps: (1) Add water to a container, heat to 65°C, add sulfosalicylic acid, L-glutamic acid-N,N-diacetic acid, disodium ethylenediaminetetraacetate, and rhamnolipid, and stir at 300 rpm for 4 min; (2) Cool down to 45°C, add 1-butyl-3-methylimidazolium tetrafluoroborate, sodium molybdate, fatty alcohol polyoxyethylene ether, and rose fragrance, and stir at 200 rpm for 8 min; (3) The mixed solution obtained in step (3) is kept under a vacuum of 0.06 MPa and a temperature of 55°C for 50 min, and then naturally cooled to room temperature (25°C) to obtain a descaling agent.

[0032] Comparative Example 5 A descaling agent comprising the following components in parts by weight: 5 parts sulfosalicylic acid, 15 parts L-glutamic acid-N,N-diacetic acid, 10 parts disodium ethylenediaminetetraacetate, 4 parts diglyceride borate, 2 parts rhamnolipid, 8 parts 1-butyl-3-methylimidazolium tetrafluoroborate, 4 parts fatty alcohol polyoxyethylene ether, 7 parts rose fragrance, and 80 parts water.

[0033] The descaling agent is prepared according to the following steps: (1) Add water to a container, heat to 65°C, add sulfosalicylic acid, L-glutamic acid-N,N-diacetic acid, disodium ethylenediaminetetraacetate, diglyceride borate, and rhamnolipid, and stir at 300 rpm for 4 min. (2) Cool down to 45°C, add 1-butyl-3-methylimidazolium tetrafluoroborate, fatty alcohol polyoxyethylene ether, and rose fragrance, and stir at 200 rpm for 8 min; (3) The mixed solution obtained in step (3) is kept under a vacuum of 0.06 MPa and a temperature of 55°C for 50 min, and then naturally cooled to room temperature (25°C) to obtain a descaling agent.

[0034] Comparative Example 6 A descaling agent comprising the following components in parts by weight: 5 parts sulfosalicylic acid, 15 parts L-glutamic acid-N,N-diacetic acid, 10 parts disodium ethylenediaminetetraacetate, 4 parts diglyceride borate, 2 parts rhamnolipid, 8 parts sodium molybdate, 4 parts fatty alcohol polyoxyethylene ether, 7 parts rose fragrance, and 80 parts water.

[0035] The descaling agent is prepared according to the following steps: (1) Add water to a container, heat to 65°C, add sulfosalicylic acid, L-glutamic acid-N,N-diacetic acid, disodium ethylenediaminetetraacetate, diglyceride borate, and rhamnolipid, and stir at 300 rpm for 4 min. (2) Cool down to 45°C, add sodium molybdate, fatty alcohol polyoxyethylene ether, and rose fragrance, and stir at 200 rpm for 8 minutes; (3) The mixed solution obtained in step (3) is kept under a vacuum of 0.06 MPa and a temperature of 55°C for 50 min, and then naturally cooled to room temperature (25°C) to obtain a descaling agent.

[0036] Boiler descaling tests were conducted on the descaling agents prepared in the above examples and comparative examples. The scale thickness in the boiler was 2 mm, and the operating temperature was 60℃. After being added to the boiler, the descaling agents were circulated for descaling. The dosage was a solution prepared by mixing the descaling agents prepared in the above examples and comparative examples with water at a volume ratio of 1:4, which was then added to the boiler for circulation at a flow rate of 0.5 m / s. The experimental results were statistically analyzed using SPSS 24.0 software. The results of the quantitative data are expressed as x ± (mean ± standard deviation). The Kolmogorov-Smirnov test was used to test the normality of the data. For data that conform to a normal distribution, the t-test was used to compare the differences in means between two groups. A p-value < 0.05 was considered statistically significant. The measurement results are shown in Tables 1-2. Table 1

[0037] Note: * indicates that compared with Example 1 group, P<0.05.

[0038] Table 2

[0039] Note: * indicates that compared with Example 1 group, P<0.05.

[0040] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A descaling agent, characterized in that, It includes the following components in parts by weight: 10-30 parts organic acid, 5-15 parts chelating agent, 3-10 parts surfactant, 5-10 parts corrosion inhibitor, 3-5 parts dispersant, 5-10 parts fragrance, and 60-100 parts water.

2. The descaling agent according to claim 1, characterized in that, The organic acid is one or more of citric acid, aminosulfonic acid, glycolic acid, sulfosalicylic acid, L-glutamic acid-N,N-diacetic acid, and gluconic acid.

3. The descaling agent according to claim 2, characterized in that, The organic acid is a mixture of sulfosalicylic acid and L-glutamic acid-N,N-diacetic acid in a mass ratio of 1:

3.

4. The descaling agent according to claim 1, characterized in that, The chelating agent is one or more of the following: disodium ethylenediaminetetraacetate, diethylenetriaminepentaacetic acid, ethylene glycol diethyl ether diaminetetraacetic acid, and aminotrimethylenephosphonic acid.

5. The descaling agent according to claim 1, characterized in that, The surfactant is a mixture of diglyceride borate and rhamnolipid in a mass ratio of 2:

1.

6. The descaling agent according to claim 1, characterized in that, The corrosion inhibitor is a mixture of 1-butyl-3-methylimidazolium tetrafluoroborate and sodium molybdate in a mass ratio of 1:

1.

7. The descaling agent according to claim 1, characterized in that, The dispersant is one or more of fatty alcohol polyoxyethylene ether, fatty alcohol polyoxyethylene ether phosphate, polyvinylpyrrolidone, and octyl glycoside.

8. The descaling agent according to claim 1, characterized in that, The fragrance is one or more of the following: rose fragrance, lavender fragrance, vanilla fragrance, tuberose fragrance, jasmine fragrance, basil fragrance, frankincense fragrance, and anise fragrance.

9. The method for preparing the descaling agent according to claim 1, characterized in that, Follow these steps: (1) Add water to a container, heat to 60-70℃, add organic acid, chelating agent and surfactant, and stir at 200-400 rpm for 3-5 minutes; (2) Cool down to 40-50℃, add corrosion inhibitor, dispersant and fragrance, and stir at 100-300 rpm for 5-10 minutes; (3) The mixed solution obtained in step (3) is kept under a vacuum of 0.04-0.08 MPa and a temperature of 50-60℃ for 40-60 min, and then naturally cooled to room temperature to obtain a descaling agent.

10. The method for preparing the descaling agent according to claim 9, characterized in that, The vacuum degree in step (3) is 0.06 MPa.

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