Accelerator for evaporator as well as preparation method and application thereof

Abstract

The accelerant is prepared from the following raw materials in parts by weight: 10 to 35 parts of polyepoxysuccinic acid, 5 to 15 parts of polyacrylic acid, 5 to 20 parts of sodium gluconate, 10 to 25 parts of polyaspartic acid, 0.2 to 5 parts of methylbenzotriazole, 0.5 to 5 parts of an initiator, 0.1 to 1 part of dodecyl dimethyl benzyl ammonium chloride and the balance of water according to 100 parts by weight. Meanwhile, the invention discloses a preparation method and application of the accelerant for the evaporator. The accelerant for the evaporator not only can effectively control scaling of inorganic matters and effectively chelate ions such as calcium and magnesium in water, but also can adjust the crystallization speed and promote precipitation and separation of salt substances, so that stable operation of a device is realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of evaporation concentration, and particularly relates to a promoter for an evaporator, a preparation method thereof, and an application thereof. Background Art

[0002] The global water resources are scarce. In order to save water, the vast majority of factories adopt the methods of comprehensive utilization and recycling of industrial water. For example, industrial cooling water is recycled, and sewage is treated at multiple levels and reused to achieve the purpose of zero discharge. Evaporation crystallization and other operations are inevitably used at the end of the treatment. At this time, the salt content in the influent water is relatively high, and the calcium and magnesium ion contents are also relatively high. The pipe walls of evaporators, heat exchangers, etc. will be corroded by these impurities, and precipitates will be generated and deposited in the pipeline to form dirt. Moreover, since the wastewater contains organic impurities, they will combine to form a composite slime, which not only affects the cooling effect of the heat exchanger equipment, forms an oxygen concentration cell, dissolves iron, and causes serious under-scale corrosion. All of these will lead to a decrease in system efficiency, a decrease in throughput, frequent shutdowns for cleaning, and a short service life. Moreover, the presence of these impurities in the concentrated liquid will affect the subsequent precipitation and separation of salts, seriously affecting the stable and efficient operation of the salt separation device.

[0003] To solve the problem of pipeline fouling and blockage in the evaporation system, those skilled in the art add slow-release scale inhibitors to the pipeline. However, the existing corrosion and scale inhibitors have poor use effects, can only remove the dirt deposits caused by impurity ions to a certain extent, have poor inhibitory effects on scale-forming substances such as organic matter and calcium and magnesium ions, and cannot specifically solve this complex scale-forming substance. The long-term use effect is not ideal; moreover, the effect is single, the crystallization rate cannot be adjusted, and there is no promoting effect on the precipitation of salts. Summary of the Invention

[0004] In view of the defects of the prior art, the present invention provides a promoter for an evaporator, which can not only effectively control inorganic fouling, effectively chelate calcium, magnesium and other ions in water, but also adjust the crystallization rate, promote the precipitation and separation of salt substances, and thus realize the stable operation of the device.

[0005] A promoter for an evaporator, calculated based on 100 parts by weight, is composed of the following raw materials: 10-35 parts of polyepoxysuccinic acid, 5-15 parts of polyacrylic acid, 5-20 parts of sodium gluconate, 10-25 parts of polyaspartic acid, 0.2-5 parts of methylbenzotriazole, 0.5-5 parts of initiator, 0.1-1 part of dodecyldimethylbenzylammonium chloride, and the balance is water.

[0006] Preferably, the initiator is a base.

[0007] Preferably, the initiator is sodium hydroxide or potassium hydroxide.

[0008] More preferably, the initiator is sodium hydroxide.

[0009] Preferably, it is composed of the following raw materials: 15-25 parts of polyepoxysuccinic acid, 8-12 parts of polyacrylic acid, 8-15 parts of sodium gluconate, 10-18 parts of polyaspartic acid, 1-3 parts of methylbenzotriazole, 2-5 parts of initiator, 0.2-0.5 parts of dodecyldimethylbenzylammonium chloride, and the balance is water.

[0010] The preparation method of the promoter for the evaporator includes the following steps: First, dissolve the initiator in water, then add methylbenzotriazole and polyepoxysuccinic acid, stir and react at 45-55 °C for 0.8-1.5 hours, add polyacrylic acid and polyaspartic acid thereto, continue to stir for 0.8-1.5 hours, and then add sodium gluconate and dodecyldimethylbenzylammonium chloride thereto, and continue to stir for 0.8-1.5 hours to obtain.

[0011] The application of the promoter for the evaporator in the evaporator is to add the promoter for the evaporator to the inlet water of the evaporator.

[0012] Preferably, the addition amount of the promoter for the evaporator is 60-100 mg / L.

[0013] Advantages of the present invention: 1. The present invention provides an efficient promoter and its preparation method, which can effectively control inorganic scale formation, effectively chelate calcium, magnesium and other ions in water, thereby preventing the further combination of inorganic scale deposits and organic substances, preventing the formation of biological slime, and inhibiting the corrosion of metals; 2. The promoter for the evaporator can act on the surface of crystal nuclei through adsorption, change the electrochemical properties of the crystal nucleus surface, strengthen the formation of crystal nuclei, enable the crystal nuclei to overcome the repulsion of the diffusion double layer and coagulate and grow, thereby regulating the crystallization rate and crystallization morphology, promoting the precipitation and separation of salt substances, promoting evaporation and crystallization, increasing the salt output and purity, and further realizing the stable operation of the device; 3. After exerting the scale inhibition effect, no water-insoluble precipitate will be generated, which can extend the system cleaning cycle, extend the service life of the equipment, and reduce the operation cost; 4. High temperature resistant, and the active ingredients will not decompose under high temperature operating environment; 5. Does not contain highly toxic components, does not contain hydrofluoric acid, fluorides, and has no obvious corrosion to metals and the human body. Description of the Drawings

[0014] Figure 1 The relationship between the dosage of the agent and the purity of the salt output; Figure 2 The relationship between the dosage of the agent and the salt output. Detailed Embodiments

[0015] Example 1 A promoter for an evaporator, which is composed of the following raw materials: 26 g of polyepoxysuccinic acid, 10 g of polyacrylic acid, 9 g of sodium gluconate, 18 g of polyaspartic acid, 3 g of methylbenzotriazole, 3 g of initiator sodium hydroxide, 0.3 g of dodecyldimethylbenzylammonium chloride, 30.7 g of water; The preparation method is as follows: First, dissolve the initiator in water, then add methylbenzotriazole and polyepoxysuccinic acid, stir and react at 50 °C for 1 hour, add polyacrylic acid and polyaspartic acid thereto, continue to stir for 1 hour, and then add sodium gluconate and dodecyldimethylbenzylammonium chloride thereto, and continue to stir for 1 hour. That's it.

[0016] Example 2 A promoter for an evaporator, which is composed of the following raw materials: 28 g of polyepoxysuccinic acid, 9 g of polyacrylic acid, 9 g of sodium gluconate, 17 g of polyaspartic acid, 3 g of methylbenzotriazole, 3 g of initiator sodium hydroxide, 0.3 g of dodecyldimethylbenzylammonium chloride, 30.7 g of water; The preparation method is the same as that of Example 1.

[0017] Example 3 A promoter for an evaporator, which is composed of the following raw materials: 21 g of polyepoxysuccinic acid, 12 g of polyacrylic acid, 11 g of sodium gluconate, 20 g of polyaspartic acid, 4 g of methylbenzotriazole, 3 g of initiator sodium hydroxide, 0.3 g of dodecyldimethylbenzylammonium chloride, 28.7 g of water; The preparation method is the same as that of Example 1.

[0018] Example 4 A promoter for an evaporator, which is composed of the following raw materials: 30 g of polyepoxysuccinic acid, 10 g of polyacrylic acid, 9.5 g of sodium gluconate, 18 g of polyaspartic acid, 4 g of methylbenzotriazole, 2.5 g of initiator sodium hydroxide, 0.2 g of dodecyldimethylbenzylammonium chloride, 25.8 g of water; The preparation method is the same as that of Example 1.

[0019] Example 5 A promoter for an evaporator, which is composed of the following raw materials: 26 g of polyepoxysuccinic acid, 10 g of polyacrylic acid, 9 g of sodium gluconate, 20 g of polyaspartic acid, 2 g of methylbenzotriazole, 4 g of initiator sodium hydroxide, 0.2 g of dodecyldimethylbenzylammonium chloride, 28.8 g of water; The preparation method is the same as that of Example 1.

[0020] Example 6 A promoter for an evaporator, which is composed of the following raw materials: 10 g of polyepoxysuccinic acid, 15 g of polyacrylic acid, 20 g of sodium gluconate, 25 g of polyaspartic acid, 5 g of methylbenzotriazole, 5 g of initiator sodium hydroxide, 1 g of dodecyldimethylbenzylammonium chloride, 19 g of water; The preparation method is the same as that of Example 1.

[0021] Example 7 A promoter for an evaporator, which is composed of the following raw materials: 35 g of polyepoxysuccinic acid, 14.2 g of polyacrylic acid, 5 g of sodium gluconate, 10 g of polyaspartic acid, 0.2 g of methylbenzotriazole, 0.5 g of initiator sodium hydroxide, 0.1 g of dodecyldimethylbenzylammonium chloride, 35 g of water; The preparation method is the same as that of Example 1.

[0022] Example 8 A promoter for an evaporator, which is composed of the following raw materials: 35 g of polyepoxysuccinic acid, 5 g of polyacrylic acid, 20 g of sodium gluconate, 25 g of polyaspartic acid, 2 g of methylbenzotriazole, 2 g of initiator sodium hydroxide, 1 g of dodecyldimethylbenzylammonium chloride, 10 g of water; The preparation method is the same as that of Example 1.

[0023] 1. Scaling inhibition effect detection Water sample to be treated: taken from the inlet water of an evaporator in a water treatment plant in northern Shaanxi. The specific water quality is shown in Table 1. Add the promoter for the evaporator provided in the examples of the present invention into the above water sample to be treated at a concentration of 100 mg / L, stir, place it at 50 °C for 24 h, then measure the calcium and barium ion concentrations in the water sample, and calculate the scaling inhibition rates of calcium carbonate scale, calcium sulfate scale, and barium sulfate scale. The results are shown in Table 2.

[0024] Table 1 Water quality analysis results of the water sample to be treated (mg / L) Water sample source pH <![CDATA[Ca 2+ > <![CDATA[Mg 2+ > <![CDATA[Ba 2+ > <![CDATA[Na + > <![CDATA[CO3 2+ > <![CDATA[HCO3 - > <![CDATA[SO4 2- > <![CDATA[Cl - > Heat exchanger inlet water 9.2 2289.3 1234.2 0 2940.5 829.1 1032.5 1842.4 2152.3 Table 2 Scaling inhibition rate effect (%) Evaporation promoter Calcium carbonate scale Calcium sulfate scale Barium sulfate scale Example 1 97.3 98.5 96.8 Example 2 98.2 98.6 96.3 Example 3 95.6 96.8 97.2 Example 4 98.7 98.3 97.9 Example 5 97.5 97.5 96.9 Example 6 98.3 98.5 97.3 Example 7 97.2 98.2 97.3 Example 8 97.9 98.1 97.8 2. Evaporation effect detection During the crystallization process of the evaporation unit, due to the continuous concentration of the evaporation liquid, various impurities in the mother liquor are enriched, the water quality deteriorates continuously, and the effect of crystal aggregation and precipitation during the forming process is poor, resulting in poor quality of the product salt. Taking the production of sodium sulfate as an example, without changing other working conditions, add promoters with different concentrations of Example 2 to the feed water of the first effect of the evaporation unit (the temperature of the evaporation unit can reach 90 °C), and evaluate by observing indicators such as salt production and salt purity. The results are shown in Figure 1 andFigure 2 ; From Figure 1 and Figure 2 it can be seen that after adding the promoter for the evaporator, the crystallization rate and crystallization form can be adjusted, the salt purity can be improved, and the precipitation and separation of salt substances can be promoted; compared with the case of not adding, the salt output and purity increase significantly. Especially when the addition amount is 60 - 100 ppm (60 - 100 mg / L), the product purity can reach 98%, which can effectively improve the operation efficiency of the device, and the device operates relatively stably.

Claims

1. An accelerator for an evaporator, characterized in that: Based on 100 parts by weight, it is composed of the following raw materials: 10 - 35 parts of polyepoxysuccinic acid, 5 - 15 parts of polyacrylic acid, 5 - 20 parts of sodium gluconate, 10 - 25 parts of polyaspartic acid, 0.2 - 5 parts of methylbenzotriazole, 0.5 - 5 parts of initiator, 0.1 - 1 part of dodecyl dimethyl benzyl ammonium chloride, and the balance is water.

2. The promoter for an evaporator according to claim 1, wherein: The initiator is an alkali.

3. The promoter for the evaporator according to claim 2, wherein: The initiator is sodium hydroxide or potassium hydroxide.

4. The promoter for the evaporator according to claim 1 or 2 or 3, characterized in that: It is composed of the following raw materials: 15 - 25 parts of polyepoxysuccinic acid, 8 - 12 parts of polyacrylic acid, 8 - 15 parts of sodium gluconate, 10 - 18 parts of polyaspartic acid, 1 - 3 parts of methylbenzotriazole, 2 - 5 parts of initiator, 0.2 - 0.5 part of dodecyl dimethyl benzyl ammonium chloride, and the balance is water.

5. The preparation method of the promoter for the evaporator according to claim 1, characterized in that: It includes the following steps: First, dissolve the initiator in water, then add methylbenzotriazole and polyepoxysuccinic acid, stir and react at 45 - 55 °C for 0.8 - 1.5 hours, add polyacrylic acid and polyaspartic acid thereto, continue stirring for 0.8 - 1.5 hours, then add sodium gluconate and dodecyl dimethyl benzyl ammonium chloride thereto, and continue stirring for 0.8 - 1.5 hours to obtain the product.

6. Use of the promoter for evaporator according to claim 1 in an evaporator, characterized in that: Add the promoter for the evaporator to the inlet water of the evaporator.

7. Use of the promoter for an evaporator according to claim 6 in an evaporator, characterized in that: The addition amount of the promoter for the evaporator is 60 - 100 mg / L.

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