High-temperature evaporative crystallization compact scale cleaning agent and preparation method thereof

Abstract

The invention provides a high-temperature evaporative crystallization compact scale cleaning agent and a preparation method thereof, and the cleaning agent is mainly prepared from the following raw materials in parts by mass: 13-30 parts of organic acid, 9-20 parts of a chelating agent, 4-15 parts of a surfactant, 0.8-5 parts of a corrosion inhibitor, 4-10 parts of a cosolvent, 0.08-1 part of a defoaming agent and 13-20 parts of deionized water. The cleaning agent can quickly and efficiently dissolve compact scale formed in the high-temperature evaporative crystallization process, and is good in cleaning effect, small in corrosion to equipment, environmentally friendly and free of pollution.

Description

Technical Field

[0001] The invention belongs to the technical field of water treatment, and in particular relates to a high-temperature evaporation crystallization dense scale cleaning agent and a preparation method thereof. Background Art

[0002] High-temperature evaporation and crystallization are critical processes in industries such as coal chemical, petrochemical, textile printing and dyeing, and power plants. However, this process can easily lead to the formation of dense scale on equipment surfaces. This scale, composed of a variety of components such as inorganic salts, organic matter, and metal oxides, has a dense structure and strong adhesion, posing significant challenges to the normal operation and maintenance of equipment.

[0003] Currently, mechanical cleaning and chemical cleaning are the two main methods for cleaning dense scale caused by high-temperature evaporation crystallization. Mechanical cleaning removes the scale layer through physical scrapers and high-pressure water jets, but this method can easily damage the equipment surface during operation, shortening its service life. Furthermore, mechanical cleaning is difficult for some complex equipment, and the cleaning effect is often unsatisfactory.

[0004] Chemical cleaning uses chemical cleaning agents to dissolve scale. While this method can achieve the desired cleaning effect to a certain extent, existing chemical cleaning agents present numerous challenges. For one thing, cleaning efficiency is low, making it difficult to meet the cleaning speed requirements of actual production. Furthermore, some chemical cleaning agents are environmentally unfriendly and contain harmful substances, potentially polluting the environment. Furthermore, some cleaning agents are highly corrosive, potentially corroding equipment and further impacting its performance and service life.

[0005] In view of this, the present invention is proposed. Summary of the Invention

[0006] The first purpose of the present invention is to provide a high-temperature evaporation crystallization dense scale cleaning agent, which can quickly and efficiently dissolve the dense scale formed in the high-temperature evaporation crystallization process, has a good cleaning effect, and is less corrosive to equipment. At the same time, this cleaning agent is environmentally friendly, friendly to the environment and operators during the cleaning process, does not produce harmful waste liquid or irritating gas, and is pollution-free.

[0007] The second purpose of the present invention is to provide a high-temperature evaporation crystallization dense scale cleaning agent. The preparation method is not only simple in process and easy to operate, but can also be stably operated under a conventional industrial production environment, thereby achieving rapid preparation of the product. Moreover, from the perspective of economy and environmental friendliness, it reduces the generation of harmful by-products and realizes a green economy.

[0008] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are adopted: The present invention provides a high-temperature evaporation crystallization dense scale cleaning agent, which is mainly prepared from the following raw materials: 13-30 parts of organic acid, 9-20 parts of chelating agent, 4-15 parts of surfactant, 0.8-5 parts of corrosion inhibitor, 4-10 parts of cosolvent, 0.08-1 part of defoaming agent and 13-20 parts of deionized water.

[0009] Preferably, as a further specific embodiment, by mass fraction, the organic acid is 15-20 parts, the chelating agent is 10-15 parts, the surfactant is 5-10 parts, the corrosion inhibitor is 0.9-3 parts, the cosolvent is 5-8 parts, the defoaming agent is 0.09-0.5 parts, and the deionized water is 14-18 parts.

[0010] Preferably, as a further specific embodiment, the composition includes, by mass, 16 parts of organic acid, 11 parts of chelating agent, 6 parts of surfactant, 1 part of corrosion inhibitor, 6 parts of cosolvent, 0.2 parts of defoaming agent, and 16 parts of deionized water.

[0011] Preferably, the organic acid is at least one of citric acid, oxalic acid and tartaric acid.

[0012] Preferably, the chelating agent is at least one of ethylenediaminetetraacetic acid and its salts, aminotriacetic acid and its salts.

[0013] Preferably, the surfactant is any one of nonylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether, and sorbitan fatty acid ester.

[0014] Preferably, the corrosion inhibitor is at least one of hexamethylenetetramine and benzotriazole.

[0015] Preferably, the co-solvent is at least one of ethanol and propylene glycol.

[0016] The high-temperature evaporation crystallization dense scale cleaning agent provided by the present invention, the combination of its various components is based on an in-depth understanding of the characteristics of dense scale and the consideration of the synergistic effect of each component; in the above-mentioned materials, its core is to first act through organic acid, and its acidic components can release hydrogen ions and directly dissolve in carbonate scale, while its carboxyl structure can combine with metal ions such as calcium and magnesium to form complexes, breaking down the scale layer framework; especially under high temperature environments, these organic acids can still maintain chemical activity. However, acid washing alone is not enough to deal with dense structure scale, so strong chelating agents such as ethylenediaminetetraacetic acid are added to the formula. These chelating agents firmly lock metal ions under high temperature conditions, decompose the originally solid lattice structure into soluble particles, fundamentally destroy the stability of the scale layer, gradually decompose the dense scale, and make its structure loose, creating favorable conditions for subsequent cleaning.

[0017] In order to improve the penetration effect of the cleaning agent in the complex equipment structure, the surfactant is added, which can reduce the surface tension of the liquid, so that the cleaning agent can quickly penetrate into the micropores of the scale layer, and after the scale body falls off, it can quickly wrap and prevent the deposition of the falling objects in the dead angle of the equipment by the electrostatic repulsion. In addition, for the mixed scale containing oil, the surfactant also plays an emulsifying and decomposing function, realizing the synchronous removal of oil stains and scale. Considering the potential corrosion risk of the acidic environment to the metal equipment, the corrosion inhibitor such as urotropine is precisely matched, which can quickly form a molecular-level protective film on the metal surface to prevent the direct contact of the cleaning agent with the metal, thereby protecting the metal matrix and prolonging the service life of the equipment. In this way, the cleaning reaction can proceed without affecting the corrosion rate. At the same time, the addition of ethanol, propylene glycol and other solubilizers plays a synergistic role, which not only enhances the solubility of organic acids and chelating agents, but also improves the flowability of the reagent, ensuring that all active components can be evenly distributed and deeply penetrated.

[0018] In the whole cleaning agent, a small amount of defoaming agent effectively inhibits the generation of foam in the circulating cleaning process, ensuring the efficiency of the equipment pumping; at the same time, the use of deionized water provides a good dissolving environment for each component, so that the cleaning agent can play a role in the appropriate concentration and state. Each component cooperates and synergizes to achieve efficient cleaning of high-temperature evaporation and crystallization dense scale, while protecting the metal body.

[0019] The present application not only provides a high-temperature evaporation and crystallization dense scale cleaning agent, but also provides a preparation method of the high-temperature evaporation and crystallization dense scale cleaning agent, comprising the following steps: The organic acid, the chelating agent and the solubilizer are sequentially added to the deionized water and mixed and stirred; Then the surfactant is added and stirred uniformly; Finally, the corrosion inhibitor and the defoaming agent are added and stirred to obtain the cleaning agent.

[0020] Preferably, the stirring rate is controlled at 200-400 r / min.

[0021] The preparation process of the present application is simple, the raw materials are widely available and easy to obtain, the cost is low, and the raw materials are harmless, which will not cause harm to the operator's body during preparation, and has high economic efficiency and practicality.

[0022] Compared with the prior art, the present application has the following advantages: The cleaning agent of the present invention, through the synergistic effect of organic acids and chelating agents, can quickly and efficiently dissolve stubborn components such as inorganic salts and metal oxides contained in high-temperature evaporated, crystallized, dense scale, thereby disintegrating the scale layer structure. Simultaneously, the addition of surfactants injects a powerful boost into the cleaning process. Its inherent properties greatly enhance the cleaning agent's ability to penetrate the scale layer, allowing it to penetrate deep into the scale layer while dispersing the dissolved scale components, allowing the cleaning agent to fully contact and function within the scale layer, thereby achieving efficient cleaning, significantly shortening the cleaning time required, and improving work efficiency.

[0023] The cleaning agent of the present invention also has unique advantages in terms of equipment protection. It can form a strong and dense protective film on the surface of the equipment. This protective film acts like a solid line of defense, effectively preventing direct contact between the cleaning agent and the metal substrate of the equipment, thereby inhibiting the cleaning agent's corrosive effects on the equipment, effectively extending the service life of the equipment and reducing the cost of repair and replacement of equipment due to corrosion. Furthermore, no toxic or harmful gases are released during the cleaning process, and no seriously polluted wastewater is produced. The waste liquid generated after cleaning can meet environmental emission standards through simple and cost-effective treatment, easily achieving standard discharge, fully complying with the current stringent requirements for environmental protection.

[0024] Whether in different temperature environments or during long-term storage, the cleaning agent of the present invention can always maintain good stability without the occurrence of stratification, precipitation and other phenomena that affect the use effect, ensuring that the cleaning agent can exert stable performance under various conditions. DETAILED DESCRIPTION

[0025] The technical scheme of the present invention will be clearly and completely described below in conjunction with specific embodiments, but it will be understood by those skilled in the art that the following described embodiments are part of embodiments of the present invention, rather than all embodiments, and are only used to illustrate the present invention, and should not be considered as limiting the scope of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work premise belong to the scope of protection of the present invention. Those who do not specify specific conditions in the embodiments are carried out according to normal conditions or the conditions recommended by the manufacturer. Those whose reagents or instruments are not specified by the manufacturer are conventional products that can be purchased commercially.

[0026] Example 1 The specific preparation method of the high-temperature evaporation crystallization dense scale cleaning agent of this embodiment is carried out according to the following steps: 16 g of deionized water was added to a stirring container, and 6 g of citric acid, 11 g of disodium ethylenediaminetetraacetic acid, and 5 g of ethanol were weighed and added to the stirring container in sequence; stirring was continued at a speed of 200 r / min for 30 min to allow all components to be fully dissolved.

[0027] Then weigh 6g of nonylphenol polyoxyethylene ether and add it into the stirring container, and stir at the same speed for 30 minutes to make it evenly dispersed.

[0028] Finally, weigh 1 g of hexamethylenetetramine and 0.1 g of polyether defoaming agent and add them into a stirring container, and stir at the same speed for 30 minutes.

[0029] Example 2 The specific preparation method of the high-temperature evaporation crystallization dense scale cleaning agent of this embodiment is carried out according to the following steps: Add 20 g of deionized water to a stirring container, and then weigh 30 g of tartaric acid, 20 g of ethylenediaminetetraacetic acid, and 10 g of a mixture of ethanol and propylene glycol (mass ratio 1:1) and add them to the stirring container in sequence; continue stirring at a speed of 400 r / min for 60 min to allow all components to be fully dissolved.

[0030] Then, 15 g of sorbitol fatty acid ester was weighed and added to the stirring container, and stirred at the same speed for 60 minutes to make it evenly dispersed.

[0031] Finally, weigh 5 g of a mixture of hexamethylenetetramine and benzotriazole (mass ratio is 1:1) and 1 g of a polyether defoamer, and stir at the same speed for 60 min.

[0032] Example 3 The specific preparation method of the high-temperature evaporation crystallization dense scale cleaning agent of this embodiment is carried out according to the following steps: 18 g of deionized water was added to a stirring container, and 20 g of oxalic acid, 15 g of aminotriacetic acid, and 8 g of propylene glycol were weighed and added to the stirring container in sequence; stirring was continued at a speed of 300 r / min for 45 min to allow all components to be fully dissolved.

[0033] Then weigh 10g of fatty alcohol polyoxyethylene ether, add it to the stirring container, and stir at the same speed for 45 minutes to make it evenly dispersed.

[0034] Finally, weigh 3 g of benzotriazole and 0.5 g of polyether defoamer and stir at the same speed for 45 minutes.

[0035] Example 4 The specific preparation method of the high-temperature evaporation crystallization dense scale cleaning agent of this embodiment is carried out according to the following steps: Add 14 g of deionized water to a stirring container, then weigh 13 g of a mixture of oxalic acid and citric acid (mass ratio 1:1), 9 g of trisodium aminotriacetic acid, and 4 g of a mixture of ethanol and propylene glycol (mass ratio 1:1) and add them to the stirring container in sequence; continue stirring at a speed of 200 r / min for 25 min to allow all components to be fully dissolved.

[0036] Then 4g of fatty alcohol polyoxyethylene ether is weighed and added to the stirring container, and stirred at the same speed for 25 min to make it uniformly dispersed.

[0037] Finally, 0.9g of benzotriazole and 0.09g of polyether antifoaming agent are weighed and stirred at the same speed for 25 min to obtain the product.

[0038] Example 5 The specific preparation method of the high-temperature evaporation crystallization compact scale cleaner of this example is operated according to the following steps: 15g of deionized water is added to the stirring container, and 15g of citric acid, 10g of disodium ethylenediaminetetraacetate, and 5g of ethanol are sequentially added to the stirring container; continuously stirred at a speed of 200r / min for 30 min to make the components fully dissolved.

[0039] Then 5g of nonylphenol polyoxyethylene ether is weighed and added to the stirring container, and stirred at the same speed for 30 min to make it uniformly dispersed.

[0040] Finally, 1g of urotropin and 0.1g of polyether antifoaming agent are weighed and stirred at the same speed for 30 min to obtain the product.

[0041] Example 6 The specific preparation method of the high-temperature evaporation crystallization compact scale cleaner of this example is operated according to the following steps: 13g of deionized water is added to the stirring container, and 13g of tartaric acid mixture, 10g of ethylenediaminetetraacetic acid, and 5g of a mixture of ethanol and propylene glycol (mass ratio 1:1) are sequentially added to the stirring container; continuously stirred at a speed of 200r / min for 35 min to make the components fully dissolved.

[0042] Then 5g of sorbitol fatty acid ester is weighed and added to the stirring container, and stirred at the same speed for 35 min to make it uniformly dispersed.

[0043] Finally, 0.8g of urotropin and 0.08g of polyether antifoaming agent are weighed and stirred at the same speed for 35 min to obtain the product.

[0044] Example 7 The specific implementation method remains the same as example 1, and only the corrosion inhibitor is replaced with equal mass of benzotriazole.

[0045] Comparative Example 1 The specific preparation method of the scale cleaner of this example is operated according to the following steps: Add 10 g of deionized water to a stirring container, and then weigh 10 g of citric acid, 7 g of disodium ethylenediaminetetraacetic acid, and 3 g of ethanol and add them to the stirring container in sequence; continue stirring at a speed of 200 r / min for 30 minutes to allow all components to be fully dissolved.

[0046] Then weigh 3g of nonylphenol polyoxyethylene ether and add it into the stirring container, and stir at the same speed for 30 minutes to make it evenly dispersed.

[0047] Finally, weigh 0.5 g of hexamethylenetetramine and 0.05 g of polyether defoaming agent and add them into a stirring container, and stir at the same speed for 30 minutes.

[0048] Comparative Example 2 The specific preparation method of the comparative example cleaning agent is carried out according to the following steps: Add 20g of deionized water into a stirring container, weigh 25g of citric acid and 18g of disodium edetate, and add them into the stirring container in sequence; stir continuously at a speed of 200r / min for 30min to fully dissolve all the components.

[0049] Comparative Example 3 The specific preparation method of the comparative example cleaning agent is carried out according to the following steps: Add 20 g of deionized water to a stirring container, and then weigh 30 g of tartaric acid, 20 g of ethylenediaminetetraacetic acid, and 10 g of a mixture of ethanol and propylene glycol (mass ratio 1:1) and add them to the stirring container in sequence; continue stirring at a speed of 400 r / min for 60 min to allow all components to be fully dissolved.

[0050] Then, 15 g of sorbitol fatty acid ester was weighed and added to the stirring container, and stirred at the same speed for 60 minutes to make it evenly dispersed.

[0051] Finally, weigh 1 g of polyether defoamer and stir at the same speed for 60 minutes.

[0052] Comparative Example 4 The cleaning agent prepared in Example 7 of patent CN112725813A and the cleaning agent prepared in Example 1 of patent CN115418277A were selected.

[0053] Experimental Example 1 The cleaning agents prepared in Examples 1-7 and Comparative Examples 1-4 were tested for their performance. At 85°C and a 15% cleaning agent concentration, the cleaning agents were used to clean simulated high-temperature evaporator surfaces made of the same material and with the same scale thickness. The results are shown in Table 1 below.

[0054] Table 1. Performance test results

[0055] Based on the above data, we can draw the following conclusions: Examples 1-7 demonstrate that, under identical experimental conditions, the cleaning agents in these examples efficiently completed the cleaning task within 1.20 hours, achieving a 100% scale dissolution rate when cleaning a simulated high-temperature evaporator made of the same material and with consistent scale thickness. This demonstrates their rapid and thorough cleaning capabilities. Furthermore, regarding equipment protection, the corrosion rates of these cleaning agents on carbon steel were significantly lower than industry standards, with a maximum of only 0.013 mm / a and a minimum of 0.007 mm / a, effectively protecting equipment and extending its service life.

[0056] In sharp contrast, Comparative Example 1 has a low cleaning efficiency due to the relatively small amount of each component used. The cleaning time is as long as 4.00 hours, the scale dissolution rate is only 60%, and the corrosion rate of carbon steel is as high as 0.085mm / a. The cleaning effect and equipment protection performance are not ideal. Comparative Example 2 does not add surfactants, which makes the cleaning efficiency also low. The cleaning time is 3.00 hours, the scale dissolution rate is only 50%, and the corrosion rate reaches 0.089mm / a. The cleaning performance and corrosion resistance are both poor. Although Comparative Example 3 has a high cleaning efficiency and can achieve a scale dissolution rate of 100% within 1.20 hours, the corrosion rate of carbon steel is as high as 0.250mm / a due to the lack of corrosion inhibitors, causing serious corrosion to the equipment. The commercially available chemical cleaning agent used in Comparative Example 4 had low cleaning efficiency under different test conditions, with cleaning times of 3.50 hours and 4.00 hours, respectively. Although the scale dissolution rate could reach 100%, the corrosion rate on carbon steel was also at a high level, at 0.076 mm / a and 0.072 mm / a, respectively, which failed to achieve both efficient cleaning and equipment protection.

[0057] In summary, the high-temperature evaporation crystallization dense scale cleaning agent of the present invention has overcome the two major contradictions in the field of high-temperature evaporation crystallization dense scale cleaning, namely the traditional dilemma of balancing efficient scale removal and equipment protection, by rationally proportioning the components. Its 1.2h extremely fast cleaning capacity is 3 times faster than that of the product in Comparative Example 4, its corrosion rate is close to zero, and its stubborn scale dissolution rate is 100%. It provides an industrial solution technology that is both economical and sustainable for scenarios such as high-salt wastewater treatment and chemical evaporation systems. In particular, its super protective performance for carbon steel and stainless steel equipment significantly extends the service life of key equipment such as evaporators and heat exchange tubes. The dual goals of efficient cleaning and effective equipment protection are achieved.

[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high-temperature evaporation crystallization dense scale cleaning agent, characterized in that: The invention is mainly prepared from the following raw materials: by weight, 13-30 parts of organic acid, 9-20 parts of chelating agent, 4-15 parts of surfactant, 0.8-5 parts of corrosion inhibitor, 4-10 parts of cosolvent, 0.08-1 part of defoaming agent and 13-20 parts of deionized water.

2. The high-temperature evaporation crystallization dense scale cleaning agent according to claim 1, characterized in that: Calculated by mass fraction, the organic acid is 15-20 parts, the chelating agent is 10-15 parts, the surfactant is 5-10 parts, the corrosion inhibitor is 0.9-3 parts, the cosolvent is 5-8 parts, the defoaming agent is 0.09-0.5 parts, and the deionized water is 14-18 parts.

3. The high-temperature evaporation crystallization dense scale cleaning agent according to claim 1, characterized in that: Calculated by mass, the ingredients include 16 parts of organic acid, 11 parts of chelating agent, 6 parts of surfactant, 1 part of corrosion inhibitor, 6 parts of cosolvent, 0.2 parts of defoaming agent, and 16 parts of deionized water.

4. The high-temperature evaporation crystallization dense scale cleaning agent according to any one of claims 1 to 3, characterized in that: The organic acid is at least one of citric acid, oxalic acid and tartaric acid.

5. The high-temperature evaporation crystallization dense scale cleaning agent according to any one of claims 1 to 3, characterized in that: The chelating agent is at least one of ethylenediaminetetraacetic acid and its salts, aminotriacetic acid and its salts.

6. The high-temperature evaporation crystallization dense scale cleaning agent according to any one of claims 1 to 3, characterized in that: The surfactant is any one of nonylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether, and sorbitol fatty acid ester.

7. The high-temperature evaporation crystallization dense scale cleaning agent according to any one of claims 1 to 3, characterized in that: The corrosion inhibitor is at least one of hexamethylenetetramine and benzotriazole.

8. The high-temperature evaporation crystallization dense scale cleaning agent according to any one of claims 1 to 3, characterized in that: The cosolvent is at least one of ethanol and propylene glycol.

9. A method for preparing the high-temperature evaporation crystallization dense scale cleaning agent according to any one of claims 1 to 8, characterized in that: The steps include: Adding organic acid, chelating agent and cosolvent into deionized water in sequence and mixing; Then add surfactant and stir it evenly; Finally, add corrosion inhibitor and defoamer and stir to obtain the product.

10. The method for preparing the high-temperature evaporation crystallization dense scale cleaning agent according to claim 9, characterized in that: The stirring rate is controlled to be 200-400 r / min.

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