Preparation method and preparation system of modified naphthalene water reducer

Abstract

The invention discloses a preparation method and a preparation system of a modified naphthalene water reducer, and relates to the technical field of preparation of modified naphthalene water reducers, and the preparation method comprises the following operation steps: S1, pretreatment: adding water, unsaturated dicarboxylic acid, styrene and sodium hypophosphite into a pretreatment reaction kettle, and heating to 60-70 DEG C under the condition of continuous stirring; according to the preparation method and the preparation system of the modified naphthalene water reducer, in the sulfonation reaction stage, generated naphthalene steam is liquefied and returns to the kettle again to participate in the reaction, and meanwhile, acid gas and the naphthalene steam are separated and then discharged, so that waste of naphthalene raw materials can be effectively reduced, the overall utilization rate of the raw materials is increased, and meanwhile, the concentration of the raw materials in the reaction kettle is ensured; the large fluctuation of the concentration of the sulfonated material caused by the loss of the raw materials is avoided, a reliable raw material basis is provided for the stable development of subsequent hydrolysis and condensation reactions, and the preparation efficiency of the modified naphthalene water reducer is improved.

Description

Technical Field

[0001] This invention relates to the field of modified naphthalene-based water-reducing agent preparation technology, and particularly to a method and system for preparing a modified naphthalene-based water-reducing agent. Background Technology

[0002] Water-reducing agents, also known as plasticizers, are admixtures that improve the rheological properties of concrete and have gradually become the fifth component of modern concrete, in addition to cement, sand, stone and water.

[0003] For example, a patent entitled "A Preparation Method of Modified Naphthalene-Based Water-Reducing Agent" (patent application number: CN201610498001.2) discloses a preparation method of modified naphthalene-based water-reducing agent. A large number of carboxyl groups, hydroxyl groups and phosphate groups are introduced into the molecular structure of the water-reducing agent. While maintaining the high water reduction rate of the naphthalene-based water-reducing agent, it can delay the hydration of cement, thereby improving the slump retention performance of concrete, so that it still has high fluidity after 2 hours, which is convenient for transportation and construction. However, during the sulfonation process of this water-reducing agent, naphthalene and concentrated sulfuric acid will produce a large amount of volatilization or decomposition at high temperature. Without effective treatment, the concentration of reactants in the sulfonation reactor is easily reduced, which affects the preparation efficiency of the modified naphthalene-based water-reducing agent.

[0004] Therefore, it is necessary to propose a preparation method and system for modified naphthalene-based water-reducing agents to solve the above problems. Summary of the Invention

[0005] The purpose of this invention is to provide a method and system for preparing a modified naphthalene-based water-reducing agent, in order to solve the problem that during the sulfonation process, naphthalene and concentrated sulfuric acid will volatilize or decompose in large quantities at high temperatures, and the lack of effective treatment will easily reduce the concentration of reactants in the sulfonation reactor, thus affecting the preparation efficiency of the modified naphthalene-based water-reducing agent.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a method for preparing a modified naphthalene-based water-reducing agent, comprising the following steps: S1. Pretreatment: Water, unsaturated dicarboxylic acid, styrene, and sodium hypophosphite are added to the pretreatment reactor. The mixture is heated to 60–70°C under continuous stirring. Then, a 32% (w / w) liquid sodium hydroxide solution is added to adjust the pH to 5–7. Next, a mixed solution of hydroxyalkyl acrylate, initiator, and water is added dropwise, controlling the dropwise rate to ensure completion within 2–4 hours. After the dropwise addition is complete, the reaction is continued at 60–70°C for another 2–4 hours. Heating is then stopped, and the mixture is discharged when cooled to approximately 40°C to obtain the cocondensation monomer. S2. Sulfonation: A homologue of naphthalene is added to a sulfonation reactor and heated to melt at 130–135°C. Then, concentrated sulfuric acid with a mass fraction of 98% is added, and the sulfonation reaction is carried out at 150–170°C for 3–4 hours to obtain sulfonated material. During this process, the naphthalene vapor generated in the sulfonation reaction is liquefied and re-participated in the reaction. At the same time, the acidic gases in the sulfonation reaction are separated from the naphthalene vapor and discharged. S3. Hydrolysis: After the sulfonated material cools down to 100-130℃, add phosphoric acid and water to carry out hydrolysis treatment for 1-2 hours to obtain hydrolysate. S4. Condensation: After the hydrolysate cools to 90-105℃, add the co-condensation monomer, then add formaldehyde solution dropwise. Carry out the condensation reaction at 100-105℃ for 3-4 hours to obtain the condensed material. S5. Neutralization and Modification: Transfer the condensate to a neutralization reactor, cool it to 60-80℃, add an alkaline neutralizing agent, adjust the pH value to 7.5-9.0, then add a nano-graphene oxide modifier and stir and disperse for 0.5-1h to obtain a modified naphthalene-based water-reducing agent.

[0007] The present invention also discloses a preparation system for a modified naphthalene-based water-reducing agent, which is applied to the above-mentioned preparation method of the modified naphthalene-based water-reducing agent. The system also includes a vessel body, wherein a liquefaction hood is provided inside the vessel body, and the liquefaction hood has an inner cavity for the flow of low-temperature heat transfer oil. The liquefaction hood has a flow channel penetrating its upper and lower surfaces, and the flow channel is inclined. The top of the vessel is rotatably provided with an inner longitudinal tube, the liquefaction hood is slidably provided on the inner longitudinal tube, the lower half of the inner longitudinal tube is provided with an outer longitudinal tube, the bottom end of the outer longitudinal tube is rotatably connected with an inner plate, the inner plate is slidably provided in the vessel body, and a transfer chamber is formed in the vessel body and below the inner plate. The top end of the outer longitudinal tube is fitted with a sliding sleeve via an elastic component. The sliding sleeve, the outer longitudinal tube, and the inner longitudinal tube rotate synchronously. An agitator is fixed on the sliding sleeve. During preparation, the naphthalene vapor generated in the sulfonation reaction is liquefied on the liquefaction hood. The acid gas remains in a gaseous state and passes through the flow channel. When the inner plate moves upward, the auxiliary acid gas quickly enters the transfer chamber through the inner and outer longitudinal pipes. When the inner plate moves downward, the acid gas is discharged out of the transfer chamber. In addition, it drives the liquefaction hood to shake up and down, and the stirring plate is attached to the bottom of the liquefaction hood to push and scrape.

[0008] Preferably, the inner diameter of the flow channel gradually decreases from bottom to top, and multiple flow channels are provided, which are evenly distributed around the axis of the liquefaction hood.

[0009] Preferably, multiple agitator plates are provided, and the multiple agitator plates are evenly distributed around the sliding sleeve.

[0010] Preferably, the elastic component includes a first spring, which is fitted onto the outside of the inner longitudinal tube, with the top end of the first spring fixedly connected to the bottom of the sliding sleeve and the bottom end of the first spring fixedly connected to the top of the outer longitudinal tube.

[0011] Preferably, the top of the liquefaction hood is connected to a sleeve, the sleeve is slidably mounted on the inner longitudinal tube, and a second spring is fitted on the inner longitudinal tube. The top of the second spring is fixedly connected to the top of the vessel body, and the bottom of the second spring is fixedly connected to the top of the sleeve.

[0012] Preferably, the top end of the inner longitudinal tube has a circular hole.

[0013] Preferably, the bottom end of the inner plate is provided with a bottom hole, which is connected to the bottom end of the outer longitudinal tube. A first one-way valve is installed inside the bottom hole. The bottom of the vessel is fixedly connected to a connecting pipe that is connected to the storage chamber, and a second one-way valve is installed on the connecting pipe.

[0014] Preferably, a motor is fixedly installed on the top of the vessel body, and the inner longitudinal tube is fixedly connected to the drive shaft of the motor.

[0015] Preferably, an electric push rod is fixedly connected to the bottom end of the vessel body, and the inner plate is fixedly connected to the telescopic end of the electric push rod.

[0016] The technical effects and advantages of this invention are as follows: 1. This invention liquefies the generated naphthalene vapor during the sulfonation reaction stage and returns it to the reactor to participate in the reaction. At the same time, acidic gases are separated from naphthalene vapor and discharged. This can effectively reduce the waste of naphthalene raw materials, improve the overall utilization rate of raw materials, and ensure the concentration of raw materials in the reactor. It also avoids large fluctuations in the concentration of sulfonated materials due to raw material loss, providing a reliable raw material basis for the stable development of subsequent hydrolysis and condensation reactions, and improving the preparation efficiency of modified naphthalene water-reducing agents. 2. Adding nano-graphene oxide enhances the adsorption stability of water-reducing agent on the surface of cement particles, reduces adsorption loss due to cement hydration, thereby extending the slump retention time. At the same time, its nano-sized structure can fill the micropores of cement hydration products, enhance the compactness of the internal structure of concrete, and further improve the mechanical properties and durability of concrete. 3. By setting up structures such as liquefaction hood, stirring plate and inner plate, naphthalene vapor is liquefied and recycled, and acid gas is separated from naphthalene vapor. At the same time, a moderate suction force is applied to ensure the liquefaction and separation effect and improve the efficiency of the preparation system. 4. This invention utilizes the movement of the inner disc to apply a moderate suction force, allowing the gas to quickly detach from the surface of the reaction liquid, reducing the probability of gas-liquid entrainment; at the same time, the suction force allows naphthalene vapor and acidic gas to flow more quickly and concentratedly towards the liquefaction hood, and in conjunction with the stirring of the stirring plate, increases the probability of collision between naphthalene vapor and the liquefaction hood, promoting its liquefaction and reflux; and this active exhaust method increases the safety of use. 5. By utilizing the movement of the inner plate, the inside of the reactor will not come into contact with the external atmosphere during the process of transporting acidic gas outward, thus preventing oxygen, moisture or impurities in the outside air from entering the reactor and preventing adverse effects on sulfonation, hydrolysis and condensation reactions. 6. By setting an inner plate, it assists in turning the reactants, applies appropriate suction force, acts as a transmission component to push the liquefaction hood upward, scrapes and cleans the inner wall of the reactor, and assists in material discharge, thereby improving the efficiency of use; 7. By setting up structures such as sliding sleeves, stirring plates, and outer longitudinal tubes, the pushing and scraping combined with up-and-down shaking accelerates the dripping speed of the liquid droplets, while driving the stirring blades to move up and down, expanding the stirring range, and realizing the self-cleaning of the liquid droplets on the stirring plate, thus ensuring the efficiency of the sulfonation treatment. 8. By setting up a stirring plate, it can agitate naphthalene vapor and acidic gas, push and scrape liquid droplets, and act as a transmission component to push the liquefaction hood upward, making operation convenient; 9. The stirring plate rotates and agitates the naphthalene vapor and acid gas below the liquefaction hood, ensuring that the naphthalene vapor and the liquefaction hood are in full and uniform contact, thus guaranteeing the liquefaction effect. At the same time, it can also prevent the naphthalene vapor from directly passing through the flow channel with the acid gas. In addition, it can also avoid continuous contact between the stirring plate and the lower surface of the liquefaction hood, thereby reducing wear and extending service life. 10. The inclined design of the flow channel ensures that after the naphthalene vapor flows from bottom to top into the flow channel, it will first contact the inner wall at the top of the flow channel, preventing it from flowing out directly and ensuring that the naphthalene vapor is fully liquefied. At the same time, the inclined design ensures that the flow channel has sufficient length for liquefaction. Attached Figure Description

[0017] Figure 1 This is a flowchart of the preparation method of the modified naphthalene-based water-reducing agent of the present invention.

[0018] Figure 2 This is a schematic diagram of the preparation system for the modified naphthalene-based water-reducing agent of the present invention.

[0019] Figure 3 This is a cross-sectional structural diagram of the preparation system for the modified naphthalene-based water-reducing agent of the present invention.

[0020] Figure 4 For the present invention Figure 3 Enlarged schematic diagram of the structure at point A in the middle.

[0021] Figure 5For the present invention Figure 3 Enlarged schematic diagram of the structure at point B.

[0022] Figure 6 For the present invention Figure 3 Enlarged schematic diagram of the structure at point C.

[0023] Figure 7 This is a schematic diagram of the liquefaction shroud and inner disc structure of the present invention.

[0024] Figure 8 For the present invention Figure 7 Enlarged schematic diagram of the structure at point D.

[0025] Figure 9 This is a schematic diagram of the liquefaction hood and flow channel structure of the present invention.

[0026] In the diagram: 1. Kettle body; 2. Liquefaction hood; 3. Flow channel; 4. Sleeve; 5. Inlet pipe; 6. Outlet pipe; 7. Inner longitudinal pipe; 8. Sliding sleeve; 9. Stirring plate; 10. Inner disc; 11. Outer longitudinal pipe; 12. Stirring blade; 13. Inner groove; 14. Inner block; 15. Bottom hole; 16. First one-way valve; 17. Transfer chamber; 18. First spring; 19. Connecting pipe; 20. Second one-way valve; 21. Electric push rod; 22. Second spring; 23. Motor; 24. Material pipe; 25. Heating ring cavity; 26. Support column; 27. Circular hole. Detailed Implementation

[0027] This invention provides, for example Figure 1 The method for preparing a modified naphthalene-based water-reducing agent includes the following steps: S1. Pretreatment: Water, unsaturated dicarboxylic acid, styrene, and sodium hypophosphite are added to the pretreatment reactor. The unsaturated dicarboxylic acid is selected from maleic acid, maleic anhydride, fumaric acid, fumaric anhydride, itaconic acid, or citraconic acid. The molar ratio of styrene, unsaturated dicarboxylic acid, and subsequently added hydroxyalkyl acrylate is controlled at (0.25–0.5):1:(1.0–1.6). The amount of sodium hypophosphite is 12–20% of the total mass of the unsaturated dicarboxylic acid, styrene, and hydroxyalkyl acrylate. The mixture was heated to 60–70°C under continuous stirring at a rate of 150–200 r / min. Then, a 32% (w / w) liquid sodium hydroxide solution was added to adjust the pH of the reaction system to 5–7. Next, a mixed solution prepared from hydroxyalkyl acrylate, an initiator, and water was added dropwise. The hydroxyalkyl acrylate was selected from either hydroxyethyl acrylate or hydroxypropyl acrylate, and the initiator was selected from one or more of potassium persulfate, ammonium persulfate, or sodium persulfate, with an amount of 0.5–2% of the total mass of the unsaturated dicarboxylic acid, styrene, and hydroxyalkyl acrylate. The dropping rate of this mixed solution was controlled to ensure completion within 2–4 hours. After the dropping was completed, the reaction was maintained at 60–70°C for another 2–4 hours. Heating was then stopped, and the mixture was cooled to approximately 40°C before being discharged to obtain the co-condensation monomer. S2. Sulfonation: A naphthalene homologue, selected from industrial naphthalene, methylnaphthalene, and β-naphthol, is added to a sulfonation reactor. The naphthalene homologue is heated and melted at 130–135°C, followed by the addition of 98% concentrated sulfuric acid at a molar ratio of (1.1–1.8):1. The sulfonation reaction is then carried out at 150–170°C for 3–4 hours to obtain the sulfonated material. During this process, the naphthalene vapor generated in the sulfonation reaction is liquefied and then re-participated in the reaction. At the same time, the acidic gases in the sulfonation reaction are separated from the naphthalene vapor and discharged. S3. Hydrolysis: After the sulfonated material cools to 100–130°C, add 85% phosphoric acid (4–12% of the mass of concentrated sulfuric acid). Stir for 10–15 minutes to fully mix the phosphoric acid with the sulfonated material. Then add deionized water (usually 0.6–1.0 times the total mass of the naphthalene homologues), adding it dropwise over 20–30 minutes to avoid sudden temperature drops. Maintain a stirring rate of 200–300 r / min during hydrolysis for 1–2 hours to obtain the hydrolysate. S4. Condensation: After the hydrolysate cools to 90–105°C, add the co-condensation monomer, which is 5–10% of the total mass of the naphthalene homologues. Stir for 20–30 min to fully integrate the co-condensation monomer with the hydrolysate. Then, add a 37% (w / w) formaldehyde solution with a molar ratio of formaldehyde to naphthalene homologues of (0.8–1.4):1, controlling the addition time at 40–60 min. Carry out the condensation reaction at 100–105°C, maintaining a stirring rate of 250–350 r / min during the reaction, for a reaction time of 3–4 h to obtain the condensate.

[0028] S5. Neutralization and modification: Transfer the condensate into a neutralization kettle, cool it to 60-80℃, and add a 32% (w / w) liquid sodium hydroxide solution as an alkaline neutralizing agent to adjust the pH of the reactants to 8-10. Subsequently, nano-graphene oxide modifier was added, with an amount of 0.1–0.3% of the total mass of naphthalene homologues, and the mixture was stirred and dispersed at a stirring rate of 300–400 r / min for 0.5–1 h to obtain the modified naphthalene-based water-reducing agent.

[0029] Furthermore, the preparation method of modified naphthalene-based water-reducing agents includes the following examples: Example 1 S1, Preprocessing 255.5 parts water, 163.3 parts fumaric acid (unsaturated dicarboxylic acid), 40.4 parts styrene, and 59.1 parts sodium hypophosphite were added to a pretreatment reactor. The mixture was heated to 60°C with continuous stirring (stirring rate 150 r / min). Then, 65.0 parts of a 32% (w / w) liquid sodium hydroxide solution were added to adjust the pH to 5. Next, a mixed solution prepared from 210.5 parts hydroxyethyl acrylate, 6.2 parts ammonium persulfate (initiator), and 200 parts water was added dropwise. The dropping rate of this mixed solution was controlled to ensure that the addition was completed within 2 hours. After the addition was completed, the reaction was continued at 60°C for another 2 hours. After that, heating was stopped, and the mixture was cooled to about 40°C before being discharged to obtain cocondensation monomer A.

[0030] S2, sulfonation A mixture of 138 parts industrial naphthalene and 28 parts methyl naphthalene (a homologue of naphthalene) was added to a sulfonation reactor and heated to melt at 130°C. Then, 145 parts of 98% concentrated sulfuric acid were added, and the reaction was carried out at 150°C for 3 hours to obtain the sulfonated material. During this process, the naphthalene vapor generated in the sulfonation reaction was liquefied using a condenser and reintroduced into the reactor via a reflux pipe. Simultaneously, a gas-liquid separator was used to separate the acidic gases generated in the sulfonation reaction. , After being separated from naphthalene vapor, it is discharged through the tail gas treatment system.

[0031] S3, hydrolysis After the sulfonated material is cooled to 100℃, 9.7 parts of 85% phosphoric acid and 100 parts of water are added for hydrolysis. During the hydrolysis process, the stirring rate is maintained at 200r / min and the hydrolysis time is 1h to obtain the hydrolysate.

[0032] S4, condensation After the hydrolysate cools to 90°C, 26.9 parts of co-condensation monomer A are added and stirred for 20 minutes to fully integrate the two. Then, 95 parts of formaldehyde solution with a mass fraction of 37% are added dropwise (dropping time 40 minutes). The condensation reaction is carried out at a temperature of 100°C, with the stirring rate maintained at 250 r / min during the reaction. The reaction time is 3 hours to obtain the condensate.

[0033] S5, neutralization and modification The condensate was transferred to a neutralization reactor and cooled to 60°C. Then, 148 parts of a 32% (w / w) liquid sodium hydroxide solution (alkaline neutralizer) were added to adjust the pH to 7.5. Next, 0.166 parts of nano-graphene oxide modifier (0.1% of the total mass of naphthalene homologues) were added and stirred and dispersed at a stirring rate of 300 r / min for 0.5 h to obtain the modified naphthalene-based water-reducing agent.

[0034] Example 2 S1, Preprocessing 258.2 parts water, 148.6 parts maleic anhydride (unsaturated dicarboxylic acid), 67.1 parts styrene, and 57.0 parts sodium hypophosphite were added to a pretreatment reactor. The mixture was heated to 65°C with continuous stirring (stirring rate 175 r / min). Then, 62.0 parts of a 32% (w / w) liquid sodium hydroxide solution were added to adjust the pH to 6. Next, a mixed solution prepared from 200.3 parts hydroxypropyl acrylate, 6.8 parts ammonium persulfate (initiator), and 200 parts water was added dropwise. The dropping rate of this mixed solution was controlled to ensure that the addition was completed within 3 hours. After the addition was completed, the reaction was continued at 65°C for another 3 hours. After that, heating was stopped, and the mixture was cooled to about 40°C before being discharged to obtain cocondensation monomer B.

[0035] S2, sulfonation A mixture of 128 parts industrial naphthalene and 46 parts β-naphthol (a homologue of naphthalene) was added to a sulfonation reactor and heated to melt at 132°C. Then, 150 parts of 98% concentrated sulfuric acid were added, and the reaction was carried out at 160°C for 3.5 hours to obtain the sulfonated material. During this process, the naphthalene vapor generated in the sulfonation reaction was liquefied using a condenser and reintroduced into the reactor via a reflux pipe. Simultaneously, a gas-liquid separator was used to separate the acidic gases generated in the sulfonation reaction. , After being separated from naphthalene vapor, it is discharged through the tail gas treatment system.

[0036] S3, hydrolysis After the sulfonated material is cooled to 115℃, 10.4 parts of 85% phosphoric acid and 100 parts of water are added for hydrolysis. During the hydrolysis process, the stirring rate is maintained at 250r / min and the hydrolysis time is 1.5h to obtain the hydrolysate.

[0037] S4, condensation After the hydrolysate cooled to 97°C, 24.4 parts of co-condensation monomer B were added and stirred for 25 minutes to fully integrate the two. Then, 132 parts of a 37% formaldehyde solution were added dropwise (dropping time 50 minutes). The condensation reaction was carried out at a temperature of 102°C, with the stirring rate maintained at 300 r / min during the reaction. The reaction time was 3.5 hours to obtain the condensate.

[0038] S5, neutralization and modification The condensate was transferred to a neutralization reactor and cooled to 70°C. Then, 142 parts of a 32% (w / w) liquid sodium hydroxide solution (alkaline neutralizer) were added to adjust the pH to 8.2. Next, 0.348 parts of nano-graphene oxide modifier (0.2% of the total mass of naphthalene homologues) were added and stirred and dispersed at a stirring rate of 350 r / min for 0.75 h to obtain the modified naphthalene-based water-reducing agent.

[0039] Example 3 S1, Preprocessing 261.4 parts water, 137.5 parts citralic acid (unsaturated dicarboxylic acid), 51.8 parts styrene, and 72.4 parts sodium hypophosphite were added to a pretreatment reactor. The mixture was heated to 70°C with continuous stirring (stirring rate 200 r / min). Then, 56.8 parts of a 32% (w / w) liquid sodium hydroxide solution were added to adjust the pH to 7. Next, a mixed solution prepared from 212.6 parts hydroxypropyl acrylate, 6.3 parts potassium persulfate (initiator), and 200 parts water was added dropwise. The dropping rate of this mixed solution was controlled to ensure that the addition was completed within 4 hours. After the addition was completed, the reaction was continued at 70°C for another 4 hours. After that, heating was stopped, and the mixture was cooled to about 40°C before being discharged to obtain cocondensation monomer C.

[0040] S2, sulfonation 162 parts of industrial naphthalene (a homologue of naphthalene) were added to a sulfonation reactor and heated to melt at 135°C. Then, 163.7 parts of 98% concentrated sulfuric acid were added, and the reaction was carried out at 170°C for 4 hours to obtain the sulfonated material. During this process, the naphthalene vapor generated in the sulfonation reaction was liquefied using a condenser and reintroduced into the reactor via a reflux pipe. Simultaneously, a gas-liquid separator was used to separate the acidic gases generated in the sulfonation reaction. , After being separated from naphthalene vapor, it is discharged through the tail gas treatment system.

[0041] S3, hydrolysis After the sulfonated material is cooled to 130°C, 8.2 parts of 85% phosphoric acid and 100 parts of water are added for hydrolysis. During the hydrolysis process, the stirring rate is maintained at 300 r / min and the hydrolysis time is 2 h to obtain the hydrolysate.

[0042] S4, condensation After the hydrolysate cooled to 105°C, 21.1 parts of co-condensation monomer C were added and stirred for 30 minutes to fully integrate the two. Then, 118 parts of formaldehyde solution with a mass fraction of 37% were added dropwise (dropping time 60 minutes). The condensation reaction was carried out at a temperature of 105°C, with the stirring rate maintained at 350 r / min during the reaction. The reaction time was 4 hours to obtain the condensate.

[0043] S5, neutralization and modification The condensate was transferred to a neutralization reactor and cooled to 80°C. Then, 162 parts of a 32% (w / w) liquid sodium hydroxide solution (alkaline neutralizer) were added to adjust the pH to 9.0. Next, 0.486 parts of nano-graphene oxide modifier (0.3% of the total mass of naphthalene homologues) were added and stirred and dispersed at a stirring rate of 400 r / min for 1 h to obtain the modified naphthalene-based water-reducing agent.

[0044] This invention liquefies the generated naphthalene vapor during the sulfonation reaction stage and returns it to the reactor to participate in the reaction. At the same time, acidic gases are separated from naphthalene vapor and discharged. This effectively reduces the waste of naphthalene-based raw materials, improves the overall utilization rate of raw materials, and ensures the concentration of raw materials in the reactor. It also avoids large fluctuations in the concentration of sulfonated materials due to raw material loss, providing a reliable raw material basis for the stable development of subsequent hydrolysis and condensation reactions, and improving the preparation efficiency of modified naphthalene-based water-reducing agents.

[0045] In addition, the addition of nano-graphene oxide, as a nanomaterial with high specific surface area, excellent dispersibility and interfacial bonding ability, has two advantages. On the one hand, its abundant oxygen-containing groups (such as hydroxyl and carboxyl groups) on the surface can form strong interactions with water-reducing agent molecules and cement particle surfaces, improving the adsorption stability of water-reducing agents on cement particle surfaces, reducing adsorption loss caused by cement hydration, and thus prolonging the slump retention time. On the other hand, the nanoscale size of nano-graphene oxide can fill the micropores of cement hydration products, enhance the compactness of the internal structure of concrete, and further improve the mechanical properties and durability of concrete.

[0046] This invention also discloses, as Figures 2-9The system for preparing a modified naphthalene-based water-reducing agent shown is applied to the above-mentioned method for preparing a modified naphthalene-based water-reducing agent. It also includes a reactor body 1, which can be used in the sulfonation treatment stage. A support column 26 is fixedly connected to the bottom of the outer wall of the reactor body 1. Three support columns 26 are provided, and the three support columns 26 are evenly distributed around the axis of the reactor body 1 to support the reactor body 1.

[0047] A heating ring cavity 25 is provided inside the wall of the vessel body 1 for the flow of a heat transfer medium to heat the inner cavity of the vessel body 1. The heat transfer medium can be heat transfer oil or the like. In actual use, a heat transfer medium flow pipe is provided to cooperate with the heating ring cavity 25 for the heat transfer medium to flow in or out. The flow of the heat transfer medium and the heating are common existing technologies and will not be described in detail here.

[0048] The side wall of the vessel body 1 is connected to a feed pipe 24, which can be used for feeding and discharging, such as industrial naphthalene. In actual use, the feed pipe 24 is equipped with a solenoid valve and other structures to control the opening and closing state of the feed pipe 24. Alternatively, two feed pipes 24 can be set up, one for feeding and the other for discharging.

[0049] To achieve the separation of naphthalene vapor and acidic gas, a liquefaction hood 2 is slidably installed inside the reactor body 1. The liquefaction hood 2 is umbrella-shaped with its tip pointing upwards, and its wall has an inner cavity for the flow of low-temperature heat transfer oil. The low-temperature heat transfer oil flows within this cavity, maintaining the surface temperature of the liquefaction hood 2 at approximately 80.5°C, close to the melting point of naphthalene. Specifically, since the melting point of naphthalene is 80.5°C and its boiling point is 217.9°C, when the naphthalene vapor generated during the sulfonation reaction flows upwards and comes into contact with the liquefaction hood 2, it liquefies into droplets and drips back into the reaction liquid inside the reactor body 1. as well as The acidic gas remains in a gaseous state, thus separating the naphthalene vapor from the acidic gas during the sulfonation reaction.

[0050] A rotating groove is provided at the top of the vessel body 1. An inner longitudinal tube 7 is rotatably arranged inside the rotating groove. The liquefaction hood 2 is slidably arranged on the inner longitudinal tube 7, and the outer ring of the liquefaction hood 2 is attached to the inner wall of the vessel body 1.

[0051] The top of the liquefaction hood 2 is connected to a sleeve 4, which is slidably mounted on the inner longitudinal tube 7. A second spring 22 is fitted onto the inner longitudinal tube 7. The top of the second spring 22 is fixedly connected to the top of the vessel body 1, and the bottom of the second spring 22 is fixedly connected to the top of the sleeve 4. The second spring 22 is used for resetting the liquefaction hood 2. An inlet pipe 5 is connected to the sleeve 4. A through groove is provided on the top of the vessel body 1 for the inlet pipe 5 to slide up and down. An outlet pipe 6 is connected to the outer edge of the liquefaction hood 2. A through groove is provided on the top of the vessel body 1 for the outlet pipe 6 to slide up and down. Since both the inlet pipe 5 and the outlet pipe 6 can slide up and down on the top of the vessel body 1, the up and down sliding of the liquefaction hood 2 is not affected.

[0052] Specifically, low-temperature heat transfer oil is supplied to the inner cavity of the liquefaction hood 2 through the inlet pipe 5 and the casing 4, and the low-temperature heat transfer oil is discharged through the outlet pipe 6, ensuring that the surface temperature of the liquefaction hood 2 is maintained at about 80.5℃, which is close to the melting point of naphthalene. Alternatively, a pump body, liquid tank, semiconductor cooling plate, or other structures can be installed in conjunction with the inlet pipe 5 and the outlet pipe 6 to achieve the circulating cooling of the low-temperature heat transfer oil.

[0053] The liquefaction hood 2 is umbrella-shaped to ensure a large contact area, and the lower surface of the liquefaction hood 2 is inclined to facilitate the sliding of liquefied droplets.

[0054] In addition, the liquefaction hood 2 has flow channels 3 that run through its upper and lower surfaces. The flow channels 3 are inclined and there are multiple flow channels 3. The multiple flow channels 3 are evenly distributed around the axis of the liquefaction hood 2.

[0055] Reference Figure 3 , Figure 4 As shown, when naphthalene vapor flows from bottom to top, some of the naphthalene vapor directly contacts the lower surface of the liquefaction hood 2, while the rest of the naphthalene vapor enters the interior of the flow channel 3 along with the acidic gas. The naphthalene vapor inside the flow channel 3 liquefies upon contact with the inner wall of the flow channel 3, while the acidic gas can be discharged directly upwards from the top of the flow channel 3. Because the flow channel 3 is inclined, after the naphthalene vapor flows from bottom to top into the flow channel 3, it will first contact the inner wall at the top of the flow channel 3, preventing it from flowing out directly and ensuring that the naphthalene vapor is fully liquefied. At the same time, the inclined design ensures that the flow channel 3 has sufficient length for liquefaction.

[0056] Meanwhile, the inner diameter of the flow channel 3 gradually decreases from bottom to top, so that the bottom of the flow channel 3 has a sufficiently large receiving area, allowing acidic gas to stably enter the interior of the flow channel 3 and be discharged; at the same time, the gradually narrowing design makes the inner diameter of the flow channel 3 gradually smaller, so that the naphthalene vapor entering the flow channel 3 with the acidic gas can fully contact the inner wall of the flow channel 3 and be rapidly liquefied.

[0057] To ensure that the liquid droplets on the liquefaction hood 2 drip off quickly, an outer longitudinal tube 11 is slidably provided on the lower half of the inner longitudinal tube 7. An inner disk 10 is rotatably connected to the bottom end of the outer longitudinal tube 11. The inner disk 10 is slidably provided inside the vessel body 1. A transfer chamber 17 is formed inside the vessel body 1 and below the inner disk 10.

[0058] An electric push rod 21 is fixedly connected to the bottom of the vessel body 1. A through groove is provided at the bottom of the vessel body 1 for the extension and retraction end of the electric push rod 21 to pass through. The inner plate 10 is fixedly connected to the extension and retraction end of the electric push rod 21. The electric push rod 21 is connected to the factory's power supply. When the extension and retraction end of the electric push rod 21 extends, it drives the inner plate 10 to move upward. When the extension and retraction end of the electric push rod 21 retracts, it drives the inner plate 10 to move downward.

[0059] An inner groove 13 is provided on the inner wall of the outer longitudinal tube 11. An inner block 14 is slidably arranged inside the inner groove 13. The inner block 14 is fixedly connected to the inner longitudinal tube 7, so that the outer longitudinal tube 11 and the inner longitudinal tube 7 can rotate synchronously and the outer longitudinal tube 11 and the inner longitudinal tube 7 always remain in communication.

[0060] In addition, a sealing ring can be set at a position such as between the outer ring of the inner plate 10 and the inner wall of the vessel body 1. The sealing ring can be made of polyimide material, but is not limited to polyimide material. It has the characteristics of high temperature resistance and corrosion resistance, which can meet the high temperature environment of S2, S3 and S4 of the above preparation method. It can also be regularly inspected and maintained by the operator and adjusted according to the specific use.

[0061] A motor 23 is fixedly installed on the top of the reactor body 1. The inner longitudinal tube 7 is fixedly connected to the drive shaft of the motor 23, and a stirring blade 12 is fixedly connected to the outer longitudinal tube 11. Multiple stirring blades 12 can be provided. The motor 23 is connected to the power supply of the factory. When the motor 23 is running, it drives the inner longitudinal tube 7 to rotate. With the cooperation of the inner tank 13 and the inner block 14, the outer longitudinal tube 11 rotates synchronously, which in turn drives the stirring blade 12 to rotate, stirring the reactants (a mixture of industrial naphthalene, concentrated sulfuric acid, etc.) in the reactor body 1, thereby achieving the stirring function and accelerating the sulfonation reaction.

[0062] Since the bottom end of the outer longitudinal tube 11 is rotatably connected to the inner plate 10, it does not affect the use of the inner plate 10, and the outer longitudinal tube 11 and the inner plate 10 can move up and down synchronously.

[0063] The top end of the outer longitudinal tube 11 is fitted with a sliding sleeve 8 via an elastic component. An agitator 9 is fixed on the sliding sleeve 8. The agitator 9 is inclined and can fit against the lower surface of the liquefaction hood 2. Multiple agitator 9s are provided and are evenly distributed around the sliding sleeve 8. The number of agitator 9s is the same as the number of flow channels 3, and the width of the agitator 9s is appropriate.

[0064] In specific configuration, the elastic component includes a first spring 18, which is fitted onto the outside of the inner longitudinal tube 7. The top end of the first spring 18 is fixedly connected to the bottom of the sliding sleeve 8, and the bottom end of the first spring 18 is fixedly connected to the top of the outer longitudinal tube 11. The first spring 18 can be made of, but is not limited to, Hastelloy C-276 material. When the outer longitudinal tube 11 rotates, the sliding sleeve 8 can be driven to rotate through the first spring 18, thereby achieving synchronous rotation of the sliding sleeve 8, the outer longitudinal tube 11, and the inner longitudinal tube 7, and synchronous rotation of the stirring plate 9. In actual use, a structure similar to an inner groove 13 and an inner block 14 can also be set between the sliding sleeve 8 and the inner longitudinal tube 7 to ensure the stability of the synchronous rotation of the stirring plate 9 and the inner longitudinal tube 7. This can be adjusted according to the specific usage.

[0065] Furthermore, the elastic support force of the first spring 18 is greater than that of the second spring 22.

[0066] When the inner plate 10 is close to the bottom of the vessel body 1, the height of the storage chamber 17 is relatively small. At this time, there is a certain distance between the stirring plate 9 and the lower surface of the liquefaction hood 2. When the motor 23 drives the stirring blade 12 to rotate, the sliding sleeve 8 and the stirring plate 9 rotate synchronously. The naphthalene vapor and acid gas are stirred at the position below the liquefaction hood 2, so that the naphthalene vapor and the liquefaction hood 2 are fully and evenly contacted, ensuring the liquefaction effect. At the same time, it can also prevent the naphthalene vapor from directly passing through the flow channel 3 with the acid gas. In addition, it can also avoid the continuous contact between the stirring plate 9 and the lower surface of the liquefaction hood 2, thereby reducing wear and extending the service life.

[0067] When the telescopic end of the control electric push rod 21 extends, it drives the inner plate 10 to move upward, the outer longitudinal tube 11 to move upward synchronously, and the stirring blade 12 to move upward. At the same time, the outer longitudinal tube 11 pushes the sliding sleeve 8 and the stirring plate 9 to move upward through the first spring 18. The stirring plate 9 rotates against the lower surface of the liquefaction hood 2, pushing and scraping the droplets on the lower surface of the liquefaction hood 2, causing them to drip down quickly and re-participate in the reaction. The stirring plate 9 pushes the liquefaction hood 2 to move upward. Since the elastic support force of the first spring 18 is greater than that of the second spring 22, the second spring 22 contracts first. After the second spring 22 is fully contracted, the liquefaction hood 2 can no longer move upward. Then the first spring 18 contracts, which can ensure that the outer longitudinal tube 11 can still move upward a certain distance.

[0068] When the telescopic end of the electric push rod 21 is retracted, it drives the inner plate 10 to move downward, the outer longitudinal tube 11 to move downward synchronously, the stirring blade 12 to move downward, the sliding sleeve 8 and the stirring plate 9 to move downward synchronously, and the reset force of the second spring 22 causes the liquefaction hood 2 to move downward and reset. Then the stirring plate 9 disengages from the lower surface of the liquefaction hood 2.

[0069] Repeating the above operation multiple times will create an up-and-down shaking effect in the liquefaction hood 2, accelerating the dripping speed of the liquid; and the stirring blade 12 will move up and down, stirring up and down while rotating, achieving a multi-directional stirring effect and expanding the stirring range.

[0070] In addition, the upward movement distance of the liquefaction hood 2 can be controlled. For example, if there are fewer droplets in the early stage of the reaction, the liquefaction hood 2 only needs to move upward a small distance.

[0071] Meanwhile, the droplets remaining on the stirring plate 9 will fall off due to the rotation and up-and-down movement of the stirring plate 9, achieving a self-cleaning effect.

[0072] By setting up structures such as the sliding sleeve 8, stirring plate 9, and outer longitudinal tube 11, the pushing and scraping combined with up-and-down shaking accelerates the dripping speed of the liquid droplets, while driving the stirring blade 12 to move up and down, expanding the stirring range, and realizing the self-cleaning of the liquid droplets on the stirring plate 9, thus ensuring the efficiency of the sulfonation treatment.

[0073] By setting up the stirring plate 9, it can agitate the naphthalene vapor and acidic gas, push and scrape the liquid droplets, and act as a transmission component to push the liquefaction hood 2 upward, making the operation convenient.

[0074] In addition, the up-and-down movement of the inner plate 10 can also help to agitate the reactants, further ensuring the efficiency of the sulfonation process.

[0075] The inner longitudinal tube 7 has a round hole 27 at its top end, which connects the inner longitudinal tube 7 to the interior of the vessel body 1. A filter screen can be installed inside the round hole 27 to prevent impurities from entering the inner longitudinal tube 7. The bottom end of the inner plate 10 has a bottom hole 15, which connects to the bottom end of the outer longitudinal tube 11. A first one-way valve 16 is installed inside the bottom hole 15. The bottom of the vessel body 1 is fixedly connected to a connecting pipe 19 that connects to the transfer chamber 17. A second one-way valve 20 is installed on the connecting pipe 19, which is connected to the plant's spraying equipment for spraying acidic gases. The spraying equipment includes structures such as a spraying tower.

[0076] A first one-way valve 16 is provided so that the gas inside the vessel body 1 can enter the interior of the transfer chamber 17 through the round hole 27, the inner longitudinal pipe 7, and the outer longitudinal pipe 11 without flowing in the opposite direction; a second one-way valve 20 is provided so that the gas inside the transfer chamber 17 can flow out through the connecting pipe 19 without flowing in the opposite direction.

[0077] In actual use, when the inner control plate 10 moves upward, the transfer chamber 17 expands. With the cooperation of the first one-way valve 16 and the second one-way valve 20, the acidic gas quickly enters the transfer chamber 17 through the round hole 27, the inner longitudinal pipe 7, and the outer longitudinal pipe 11. When the inner control plate 10 moves downward, the acidic gas in the transfer chamber 17 is discharged to the outside through the connecting pipe 19 for spray treatment.

[0078] Considering that after naphthalene vapor and acidic gas mix in the vessel 1, if they only rely on natural buoyancy to diffuse upwards, the slow flow rate may cause some of the gas to be entrained by the reaction liquid in the vessel 1 (forming bubbles or aerosols), making effective separation difficult, this invention utilizes the movement of the inner plate 10 to apply a moderate suction force, allowing the gas to quickly detach from the surface of the reaction liquid and reducing the probability of gas-liquid entrainment; at the same time, the suction force can make the naphthalene vapor and acidic gas flow more quickly and more concentratedly to the liquefaction hood 2, and in conjunction with the stirring of the stirring plate 9, increase the probability of collision between the naphthalene vapor and the liquefaction hood 2, promoting its liquefaction and reflux; and this active exhaust method increases the safety of use.

[0079] By setting up structures such as the liquefaction hood 2, the stirring plate 9, and the inner disk 10, naphthalene vapor is liquefied and recycled, and acidic gas is separated from naphthalene vapor. At the same time, a moderate suction force is applied to ensure the liquefaction and separation effect and improve the efficiency of the preparation system.

[0080] At the same time, by utilizing the movement of the inner plate 10, the inside of the vessel 1 will not come into contact with the external atmospheric environment during the process of acid gas being transported outward, thus preventing oxygen, moisture or impurities in the external air from entering the vessel 1 and preventing adverse effects on the sulfonation, hydrolysis and condensation reactions.

[0081] In actual use, a pressure sensor can be installed at the vessel body 1 to detect the pressure inside the vessel body 1. The sliding distance of the inner plate 10 can be controlled according to the pressure inside the vessel body 1. If the pressure inside the vessel body 1 is large, the inner plate 10 can be controlled to slide upward a larger distance. Adjustments can be made according to the specific usage conditions.

[0082] When the reaction is complete and the vessel body 1 needs to be cleaned, the inner plate 10 is controlled to move upward, which can push and scrape the inner wall of the vessel body 1. For example, when it moves to the bottom of the material pipe 24, the lower half of the inner wall of the vessel body 1 is automatically pushed and scraped to clean it, reducing the workload of the operators.

[0083] In addition, during discharge, the inner plate 10 is controlled to move slowly upward and to the bottom of the feed pipe 24, so that the reactants can be discharged quickly by corresponding to the feed pipe 24.

[0084] By setting the inner plate 10, it can assist in turning the reactants, apply appropriate suction force, act as a transmission component to push the liquefaction hood 2 upward, push and scrape the inner wall of the reactor body 1, and assist in material discharge, thereby improving the efficiency of use.

Claims

1. A method for preparing a modified naphthalene-based water reducing agent, characterized by: The method comprises the following steps: S1, pretreatment, water, unsaturated dicarboxylic acid, styrene and sodium hypophosphite are put into a pretreatment reactor, heated to 60-70℃ under continuous stirring, then 32% mass fraction of liquid sodium hydroxide solution is added, the pH value is adjusted to 5-7, then a mixed solution prepared by hydroxyalkyl acrylate, initiator and water is added dropwise, the dropwise adding speed is controlled to ensure that the dropwise adding is completed within 2-4h, after the dropwise adding is completed, the temperature is still kept at 60-70℃ for 2-4h, then the heating is stopped, and the material is discharged when the temperature is cooled to about 40℃, to obtain a copolymerization monomer; S2, sulfonation, a homolog of naphthalene is put into a sulfonation reactor, and heated to melt at a temperature of 130-135℃, then 98% mass fraction of concentrated sulfuric acid is added, and sulfonation is carried out at a temperature of 150-170℃ for 3-4h to obtain sulfonated material; during the sulfonation, the naphthalene vapor generated in the sulfonation is liquefied and reused, and the acid gas and naphthalene vapor in the sulfonation are separated and discharged; S3, hydrolysis, after the sulfonated material is cooled to 100-130℃, phosphoric acid and water are added for hydrolysis, the hydrolysis time is 1-2h, and a hydrolyzed liquid is obtained; S4, condensation, after the hydrolyzed liquid is cooled to 90-105℃, the copolymerization monomer is added, and formaldehyde solution is added dropwise, and condensation is carried out at a temperature of 100-105℃ for 3-4h to obtain a condensed material; S5, neutralization and modification, the condensed material is transferred into a neutralization reactor, cooled to 60-80℃, and then an alkaline neutralizing agent is added to adjust the pH value to 7.5-9.0, then a nano graphene oxide modifier is added and stirred and dispersed for 0.5-1h to obtain a modified naphthalene-based water reducing agent.

2. A system for preparing a modified naphthalene-based water reducing agent, characterized by: The preparation method of the modified naphthalene-based water reducing agent of claim 1 further comprises a kettle body (1), the inside of the kettle body (1) is provided with a liquefaction cover (2), the liquefaction cover (2) has an inner cavity for the flow of low-temperature heat-conducting oil, the liquefaction cover (2) has a flow channel (3) penetrating through its upper and lower surfaces, and the flow channel (3) is inclined; the top end of the kettle body (1) is rotatably provided with an inner vertical pipe (7), the liquefaction cover (2) is slidably arranged on the inner vertical pipe (7), the lower half of the inner vertical pipe (7) is provided with an outer vertical pipe (11), the bottom end of the outer vertical pipe (11) is rotatably connected with an inner disc (10), the inner disc (10) is slidably arranged in the kettle body (1), and a transfer chamber (17) is formed in the kettle body (1) below the inner disc (10); the top end of the outer vertical pipe (11) is mounted with a sliding sleeve (8) through an elastic assembly, the sliding sleeve (8), the outer vertical pipe (11) and the inner vertical pipe (7) rotate synchronously, and the sliding sleeve (8) is fixed with a stirring plate (9); In the preparation, the naphthalene vapor generated in the sulfonation reaction is liquefied on the liquefaction cover (2), the acid gas is maintained in the gaseous state and passes through the flow channel (3), and when the inner disc (10) moves upward, the auxiliary acid gas is quickly introduced into the storage chamber (17) from the inner vertical pipe (7) and the outer vertical pipe (11), and when the inner disc (10) moves downward, the acid gas is discharged from the storage chamber (17) to the outside, and the liquefaction cover (2) is shaken up and down, and the stirring plate (9) is attached to the bottom of the liquefaction cover (2) to push and scrape.

3. The system for preparing a modified naphthalene-based water reducing agent according to claim 2, characterized in that: The inner diameter of the flow channel (3) gradually decreases from bottom to top, and the flow channel (3) is provided with a plurality of flow channels (3) which are uniformly distributed around the axis of the liquefaction cover (2).

4. The system for preparing a modified naphthalene series water reducing agent according to claim 2, characterized by: The stirring plate (9) is provided with a plurality of stirring plates (9) which are uniformly distributed around the sliding sleeve (8).

5. The system for preparing a modified naphthalene-based water reducing agent according to claim 2, characterized in that: The elastic assembly includes a first spring (18), the first spring (18) is sleeved on the outside of the inner vertical pipe (7), the top end of the first spring (18) is fixedly connected to the bottom of the sliding sleeve (8), and the bottom end of the first spring (18) is fixedly connected to the top of the outer vertical pipe (11).

6. The system for preparing a modified naphthalene-based water reducing agent according to claim 2, characterized by: The top end of the liquefaction cover (2) is communicated with a sleeve box (4), the sleeve box (4) is slidably arranged on the inner vertical pipe (7), the inner vertical pipe (7) is sleeved with a second spring (22), the top end of the second spring (22) is fixedly connected to the top of the kettle body (1), and the bottom end of the second spring (22) is fixedly connected to the top of the sleeve box (4).

7. The system for preparing a modified naphthalene-based water reducing agent according to claim 2, characterized by: The top end of the inner vertical pipe (7) is provided with a circular hole (27).

8. The system for preparing a modified naphthalene-based water reducing agent according to claim 2, characterized by: The bottom end of the inner disc (10) is provided with a bottom hole (15), the bottom hole (15) is communicated with the bottom end of the outer vertical pipe (11), a first one-way valve (16) is mounted in the bottom hole (15), the bottom of the kettle body (1) is fixedly connected with a butt joint pipe (19) communicated with the storage chamber (17), and a second one-way valve (20) is mounted on the butt joint pipe (19).

9. The system for preparing a modified naphthalene-based water reducing agent according to claim 2, characterized by: The top of the kettle body (1) is fixedly connected with a motor (23), and the inner vertical pipe (7) is fixedly connected with the driving shaft of the motor (23).

10. The preparation system of the modified naphthalene-based water-reducing agent according to claim 2, characterized in that: The bottom end of the kettle body (1) is fixedly connected with an electric push rod (21), and the inner disc (10) is fixedly connected with the telescopic end of the electric push rod (21).

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