Preparation method of slump-retaining polycarboxylate superplasticizer and storage powder spraying equipment

Abstract

The invention discloses a preparation method of a slump-retaining polycarboxylate superplasticizer and storage powder spraying equipment, and relates to the technical field of polycarboxylate superplasticizer production.The preparation method comprises the following steps that a material A is prepared, specifically, 15-40 parts of acrylic acid and 30-60 parts of distilled water are taken, stirred and mixed; preparing a material B: taking 0.5-2 parts of a reducing agent, 1-3 parts of a chain transfer agent and 40-80 parts of distilled water, and mixing and stirring; the preparation method comprises the following steps: mixing 300-500 parts of unsaturated polyether macromonomer and 200-300 parts of distilled water, and stirring at normal temperature for 10 minutes; adding 10-30 parts of acrylic acid and 1-3 parts of an oxidizing agent, and stirring for 10 minutes; adding the material A and the material B at the same time, adding 100-200 parts of distilled water 1.5 h later, and stirring for 15 min; lime milk is added, powder spraying is carried out after the pH is adjusted to be within the range of 8-9, the effects of improving the adaptability of the polycarboxylic acid water reducing agent to concrete prepared from machine-made sand in the acting process and improving the water reducing performance and the slump retaining performance in the acting process are achieved, and the use adding amount of the water reducing agent can be reduced.

Description

Technical Field

[0001] The present application relates to the technical field of polycarboxylate water reducer production, and in particular to a method for preparing a collapse-resistant polycarboxylate water reducer and a storage powder spraying device. Background Art

[0002] Polycarboxylate water reducer is a high-performance water reducer and a cement dispersant commonly used in cement concrete applications.

[0003] With the strengthening of supervision on natural sand resources, machine-made sand has gradually replaced river sand as the raw material for concrete. Compared with river sand, machine-made sand has problems such as large fluctuation range of stone powder content and strong sensitivity to polycarboxylic acid admixtures. Therefore, the performance of the produced concrete is difficult to be stably controlled, which can easily lead to problems such as poor concrete fluidity, poor encapsulation, easy segregation and bleeding, high admixture dosage, and rapid concrete collapse.

[0004] At present, polycarboxylic acid water-reducing agents pay more attention to the improvement of water-reducing rate or slump-preserving effect, and pay less attention to the slump-preserving property and material sensitivity of concrete produced with machine-made sand as raw material. Water-reducing water-reducing agents and slump-preserving water-reducing agents are often added separately during the compounding process, so as to have certain initial water-reducing and slump-preserving effects at the same time. However, this approach is very likely to bring disadvantages such as delayed concrete reaction. Summary of the invention

[0005] In order to improve the problems of delayed concrete reaction, poor water reduction and slump retention when polycarboxylic acid water reducer is used in concrete mix with machine-made sand as raw material, the present application provides a slump-retaining polycarboxylic acid water reducer preparation method and storage powder spraying equipment.

[0006] The present application provides a method for preparing a collapse-retaining polycarboxylate water-reducing agent using the following technical solution:

[0007] A method for preparing a collapse-retaining polycarboxylate water-reducing agent comprises the following steps:

[0008] S1. Preparation of chain transfer agent: Add 1-1.5 parts of mercaptoacetic acid, 6-8 parts of carbon disulfide and 15-20 parts of methanol solvent into a reaction kettle, pass nitrogen for 2 hours and then cool for 1-2 hours;

[0009] Then slowly add 30-40 parts of N,N-dimethylformamide, and then add 20-25 parts of benzyl bromide, 80-100 parts of distilled water and 10-15 parts of concentrated sulfuric acid, mix, pass nitrogen for 1-2 hours, and then cool for 2-3 hours;

[0010] React under nitrogen and room temperature for 8-10h;

[0011] After stirring for 2 hours, the reaction solution was filtered, dried, and then recrystallized to obtain a chain transfer agent;

[0012] The parts used in the chain transfer agent preparation are used alone as a ratio in this step only;

[0013] S2. Prepare material A: Take 15-40 parts of acrylic acid and 30-60 parts of distilled water, stir and mix;

[0014] S3, prepare material B: take 0.5-2 parts of reducing agent, 1-3 parts of chain transfer agent and 40-80 parts of distilled water, mix and stir;

[0015] S4, mix 300-500 parts of unsaturated polyether macromonomer and 200-300 parts of distilled water, and stir at room temperature for 10 minutes;

[0016] S5, add 10-30 parts of acrylic acid and 1-3 parts of oxidant and stir for 10 minutes;

[0017] S6. Add material A and material B at the same time. After 1.5 hours, add 100-200 parts of distilled water and stir for 15 minutes.

[0018] S7. Add lime milk, adjust the pH to within the range of 8-9 and then spray powder.

[0019] Optionally, the unsaturated polyether macromonomer is isobutylene polyethylene glycol ether, the oxidant is hydrogen peroxide, and the reducing agent is vitamin C.

[0020] Optionally, in step S6, the time for complete addition of material A and material B is set to 3.5 hours.

[0021] Optionally, in step S7, after pH adjustment is completed, powder spraying is performed at a temperature of 25-35°C.

[0022] The present application also provides a collapse-preserving polycarboxylate water-reducing agent storage and powder spraying device using the following scheme:

[0023] include

[0024] Kettle body;

[0025] The reaction ring shell is provided with an upper opening and is installed at the top of the kettle body. The feed opening of the kettle body is located at the top and above the reaction ring shell. The space formed by the circumferential outer wall of the reaction ring shell and the inner wall of the kettle body is the external heating chamber, and the space surrounded by the circumferential inner wall of the reaction ring shell is the internal heating chamber.

[0026] The part of the kettle body below the reaction ring shell is the powder spraying area;

[0027] The motor is installed on the top of the kettle body, the rotating shaft extends into the inner heating chamber and is fixed with a first gear, the first gear is meshed with a second gear, the second gear is mounted on the top of the inner wall of the reaction kettle body, the second gear is meshed with a gear housing, a rotating rod is fixed at the bottom of the gear housing, the rotating rod is rotatably mounted in the inner heating chamber, and the rotating rod extends into the powder spraying area;

[0028] The heating plate is fixed at the bottom end of the motor rotating rod and is in the shape of an umbrella protruding upwards;

[0029] The heating wire is arranged under the heating plate in a spiral arrangement;

[0030] A nozzle is arranged at the bottom of the reaction ring shell, communicated with the interior of the reaction ring shell, and faces the heating plate;

[0031] The scraper plate is mounted above the heating plate, fits with the upper surface of the heating plate, and is located on the side of the nozzle away from the rotation direction of the heating plate. The scraper plate is tilted and can guide the contacted object downward;

[0032] The unloading frame is arranged at the bottom of the kettle body and below the end of the scraper plate, is arranged to be inclined downward and extends out from the kettle body.

[0033] Optionally, an opening is provided in the middle of the heating plate, and a connecting hole is provided in the middle of the bottom end of the rotating rod, and the connecting hole is connected to the inner heating cavity.

[0034] Optionally, a plurality of reinforcing plates are fixedly provided on the inner wall of the kettle body, the reinforcing plates are vertically arranged and fixedly connected to the circumferential outer wall of the reaction ring shell.

[0035] Optionally, a negative pressure hole is opened on the top of the kettle body and is connected to the negative pressure fan through a pipeline.

[0036] Optionally, a plurality of groups of positioning plates are fixedly arranged on the inner wall of the reaction ring shell, and each group has two positioning plates, which are arranged up and down and have a hole in the middle;

[0037] The two positioning plates in each group are vertically slidably connected with a sliding rod;

[0038] A plurality of rotating paddles are rotatably connected to the sliding rod;

[0039] An undulating ring is fixedly arranged on the part of the rotating shaft of the motor in the kettle body, and the surrounding parts of the undulating ring are arranged to be undulated up and down, and a track groove is opened on the circumferential outer wall of the undulating ring;

[0040] A driving rod which can be slidably connected with the track groove is fixedly arranged on the top of the sliding rod.

[0041] Optionally, a partially rotating paddle is below the lowermost positioning plate.

[0042] In summary, the present application includes at least one of the following beneficial technical effects:

[0043] 1. By introducing polyether macromonomers into hydrophobic long side chains, steric hindrance and other steric repulsion are provided, thereby improving the dispersibility and dispersion retention performance of the water reducer. At the same time, unsaturated carboxylic acid monomers are introduced into the main chain to improve the anchoring, solubilization, and electrostatic repulsion, and improve the adsorption of cement to the water reducer. The effect in concrete is reflected in low sensitivity and improved strength, water reduction rate and slump retention, and the effect on machine-made sand is improved;

[0044] 2. Add acrylic acid in two parts, one part is used as the base material, and the other part is added to the reaction ratio of the system as a small material, which can effectively improve the fluidity of the net slurry in the cement material;

[0045] 3. The self-made chain transfer agent is added to the reaction to make the chain transfer effect better than that of market products such as mercaptoethanol. In the redox system composed of hydrogen peroxide and vitamin C, a free radical polymerization reaction occurs with acrylic acid. Compared with mercaptoethanol, the main chain length is more suitable, the side chain density is higher than that of mercaptoethanol, and the reaction is more complete.

[0046] 4. The slow addition of material A and material B can increase the conversion rate of the polyether macromonomer, making the molecular conformation of the polycarboxylate water-reducing agent more and more extended, while increasing the molecular weight of the polycarboxylate water-reducing agent and narrowing the molecular weight distribution, achieving optimal performance within the set time;

[0047] 5. The produced water-reducing agent is discharged into the reaction ring shell, and the water-reducing agent is sprayed on the heating plate through the nozzle. The rotation of the motor drives the rotating rod to rotate, and then drives the heating plate to rotate, so that the water-reducing agent dried on the heating plate abuts against the scraper plate and falls into the unloading frame, and the powder spraying process of the water-reducing agent is realized. In this process, the heat generated by the heating wire heats the air, and while heating the heating plate, it also heats the inner heating chamber and the outer heating chamber, thereby maintaining the appropriate temperature of the water-reducing agent at the same time, reducing the heat loss of the water-reducing agent before powder spraying, and improving the heat uniformity of the water-reducing agent;

[0048] 6. While the motor is rotating, it will also drive the sliding rod to move up and down through the raised ring plate, and then rotate while the rotating paddle contacts the water reducer, and drive the nearby water reducer to flow, so that the heat distribution of the water reducer is more uniform, and the deposition phenomenon during the powder spraying process is reduced, and the uniformity of the quality of the water reducer after powder spraying is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 is a schematic diagram of the structure of Example 6 of the present application;

[0050] Figure 2 is a cross-sectional view of Example 6 of the present application;

[0051] Figure 3 is a cross-sectional view showing a stirring assembly according to Example 6 of the present application;

[0052] Figure 4 This is Example 6 of the present application Figure 3 Part A in the middle shows an enlarged view of the reduction assembly.

[0053] In the figure, 1, kettle body; 11, inner heating chamber; 12, outer heating chamber; 121, reinforcement plate; 13, powder spraying chamber; 14, negative pressure hole; 15, nozzle; 2, motor; 21, rotating rod; 211, heating plate; 212, connecting hole; 3, speed reduction assembly; 31, first gear; 32, second gear; 33, gear housing; 4, heating wire; 5, scraper plate; 6, unloading frame; 7, stirring assembly; 71, sliding rod; 711, driving rod; 72, rotating paddle; 73, undulating ring; 731, track groove; 8, reaction ring shell; 81, positioning plate. DETAILED DESCRIPTION

[0054] The present application discloses a method for preparing a collapse-retaining polycarboxylic acid water-reducing agent.

[0055] Example 1

[0056] The preparation method of the collapse-retaining polycarboxylate water-reducing agent comprises the following steps:

[0057] S1. Preparation of chain transfer agent: Add 1 part of mercaptoacetic acid, 6 parts of carbon disulfide and 15 parts of methanol solvent into a reaction kettle with a cooling tube, pass nitrogen for 2 hours, and then cool through a cooling tube for 1-2 hours;

[0058] Then slowly add 30 parts of N,N-dimethylformamide, and then add 20 parts of benzyl bromide, 80 parts of distilled water and 10 parts of concentrated sulfuric acid, mix, pass nitrogen for 1-2 hours, and then cool through a cooling tube for 2-3 hours;

[0059] React under nitrogen and room temperature for 8-10h;

[0060] After stirring for 2 hours, the reaction solution was filtered, dried, and then recrystallized to obtain a chain transfer agent;

[0061] The parts used in the chain transfer agent preparation are used alone as a ratio in this step only;

[0062] S2. Prepare material A: Take 15 parts of acrylic acid and 30 parts of distilled water, stir and mix;

[0063] S3, prepare material B: take 0.5 parts of vitamin C, 1 part of chain transfer agent and 40 parts of distilled water, mix and stir;

[0064] S4, mix 300 parts of isobutylene polyethylene glycol ether and 200 parts of distilled water, and stir at room temperature for 10 minutes;

[0065] S5, add 10 parts of acrylic acid and 1 part of hydrogen peroxide and stir for 10 minutes;

[0066] S6. Add material A and material B at the same time. The time for complete addition of material A and material B is set to 3.5 hours. 1.5 hours after the addition, add 100 parts of distilled water and stir for 15 minutes.

[0067] S7. Add lime milk, adjust the pH to 8-9 and then spray at 25-35°C.

[0068] Example 2

[0069] The difference from Example 1 is that the ratio of chain transfer agent preparation is different:

[0070] Add 1.5 parts of mercaptoacetic acid, 8 parts of carbon disulfide and 20 parts of methanol solvent into a reaction kettle with a cooling tube, pass nitrogen for 2 hours, and then cool through the cooling tube for 1-2 hours;

[0071] Then slowly add 40 parts of N,N-dimethylformamide, and then add 25 parts of benzyl bromide, 100 parts of distilled water and 15 parts of concentrated sulfuric acid, mix, pass nitrogen for 1-2 hours, and then cool through a cooling tube for 2-3 hours;

[0072] React under nitrogen and room temperature for 8-10h;

[0073] After stirring for 2 hours, the reaction solution was filtered, dried, and then recrystallized to obtain a chain transfer agent.

[0074] Example 3

[0075] The difference from Example 1 is that the ratio of chain transfer agent preparation is different:

[0076] Add 1.2 parts of mercaptoacetic acid, 8 parts of carbon disulfide and 18 parts of methanol solvent into a reaction kettle with a cooling tube, pass nitrogen for 2 hours, and then cool through the cooling tube for 1-2 hours;

[0077] Then slowly add 36 parts of N,N-dimethylformamide, and then add 24 parts of benzyl bromide, 85 parts of distilled water and 12 parts of concentrated sulfuric acid, mix, pass nitrogen for 1-2 hours, and then cool through a cooling tube for 2-3 hours;

[0078] React under nitrogen and room temperature for 8-10h;

[0079] After stirring for 2 hours, the reaction solution was filtered, dried, and then recrystallized to obtain a chain transfer agent.

[0080] The following table shows the slurry flow test of the water reducing agent prepared in Examples 1-3 added to the machine-made sand cement at a solid content of 0.18%, and the test method is implemented in accordance with GB / T8077-2012.

[0081] Table 1 Flow test of the pure slurry of the water reducing agent obtained in Examples 1-3 added to the machine-made sand cement at a solid content of 0.18%

[0082]

[0083] Combined with the data in Table 1, it can be seen that the chain transfer agent ratio used in Example 3 has the best effect.

[0084] Example 4

[0085] Compared with Example 3, Example 4 has the same composition ratio of the chain transfer agent, and is described starting from step S2:

[0086] S2. Prepare material A: Take 28 parts of acrylic acid and 45 parts of distilled water, stir and mix;

[0087] S3, prepare material B: take 1.5 parts of vitamin C, 2 parts of chain transfer agent and 60 parts of distilled water, mix and stir;

[0088] S4, taking 400 parts of isobutylene polyethylene glycol ether and 250 parts of distilled water, mixing, and stirring at room temperature for 10 minutes;

[0089] S5, add 20 parts of acrylic acid and 2 parts of hydrogen peroxide and stir for 10 minutes;

[0090] S6. Add material A and material B at the same time. The time for complete addition of material A and material B is set to 3.5 hours. 150 parts of distilled water are added 1.5 hours after the addition is completed, and stirred for 15 minutes.

[0091] S7. Add lime milk, adjust the pH to 8-9 and then spray at 25-35°C.

[0092] Example 5

[0093] The difference between Example 5 and Example 4 is that:

[0094] S2. Prepare material A: Take 40 parts of acrylic acid and 60 parts of distilled water, stir and mix;

[0095] S3, prepare material B: take 2 parts of vitamin C, 3 parts of chain transfer agent and 80 parts of distilled water, mix and stir;

[0096] S4, take 500 parts of isobutylene polyethylene glycol ether and 300 parts of distilled water, mix them, and stir them at room temperature for 10 minutes;

[0097] S5, add 15 parts of acrylic acid and 3 parts of hydrogen peroxide and stir for 10 minutes;

[0098] S6. Add material A and material B at the same time. The time for complete addition of material A and material B is set to 3.5 hours. 1.5 hours after the addition, add 200 parts of distilled water and stir for 15 minutes.

[0099] S7. Add lime milk, adjust the pH to 8-9 and then spray at 25-35°C.

[0100] Comparative Example 1

[0101] The difference between Comparative Example 1 and Example 3 is that:

[0102] In step S3, the chain transfer agent is replaced with mercaptoethanol in a ratio of 1 part.

[0103] Comparative Example 2

[0104] The chain transfer agent composition ratio in Comparative Example 2 is the same as that in Example 3, except that:

[0105] S2. Prepare material A: Take 20 parts of acrylic acid and 45 parts of distilled water, and stir and mix;

[0106] S3, prepare material B: take 1.5 parts of vitamin C, 0.5 parts of chain transfer agent and 60 parts of distilled water, mix and stir;

[0107] S4, taking 400 parts of isobutylene polyethylene glycol ether and 250 parts of distilled water, mixing, and stirring at room temperature for 10 minutes;

[0108] S5, add 2 parts of hydrogen peroxide and stir for 10 minutes;

[0109] S6. Add material A and material B at the same time. The time for complete addition of material A and material B is set to 3.5 hours. 150 parts of distilled water are added 1.5 hours after the addition is completed, and stirred for 15 minutes.

[0110] S7. Add lime milk, adjust the pH to 8-9 and then spray at 25-35°C.

[0111] Comparative Example 3

[0112] The difference of Comparative Example 3 is that there is no preparation of chain transfer agent, no addition of chain transfer agent, and the S1 step is deleted and reordered as follows:

[0113] S1. Prepare material A: Take 40 parts of acrylic acid and 60 parts of distilled water, stir and mix;

[0114] S2. Prepare material B: Take 2 parts of vitamin C and 80 parts of distilled water, mix and stir;

[0115] S3, take 500 parts of isobutylene polyethylene glycol ether and 300 parts of distilled water, mix them, and stir them at room temperature for 10 minutes;

[0116] S4, add 30 parts of acrylic acid and 3 parts of hydrogen peroxide and stir for 10 minutes;

[0117] S5. Add material A and material B at the same time. The time for complete addition of material A and material B is set to 3.5 hours. 1.5 hours after the addition, add 200 parts of distilled water and stir for 15 minutes.

[0118] S6. Add lime milk, adjust the pH to 8-9 and then spray at 25-35°C.

[0119] The following table shows the slurry flow test of the water reducing agent prepared in Examples 4-5 and Comparative Examples 1-3 added to the machine-made sand cement at a solid content of 0.18%, and the test method is implemented in accordance with GB / T8077-2012.

[0120] Table 2 Flow test of the pure slurry of the water reducing agent obtained in Examples 4-5 and Comparative Examples 1-3 added with 0.18% of the solid content of the machine-made sand cement

[0121]

[0122] As can be seen from the data in Table 2, the chain transfer agent prepared in the present embodiment is better than the method of using mercaptoethanol as a chain transfer agent in the water-reducing agent ratio. In the redox system composed of hydrogen peroxide and vitamin C, free radical polymerization occurs with acrylic acid, which is more suitable than the main chain length produced by mercaptoethanol, and the side chain density is higher than the side chain density produced by mercaptoethanol, and the reaction is more sufficient. Acrylic acid is divided into two parts for addition at the same time, one part is used as a base material, and the other part is added to the reaction ratio of the system and added as a small material alone, which can effectively improve the fluidity of the net slurry acting on the cement material. By introducing polyether macromonomers into hydrophobic long side chains, steric repulsion such as steric hindrance is provided, and then the dispersibility and dispersion retention performance of the water-reducing agent are improved, and the strong polar anionic groups on the main chain are introduced by unsaturated carboxylic acid monomers to improve anchoring, solubilization, and provide electrostatic repulsion. The adsorption of cement to water-reducing agent is improved, and the effect in concrete is reflected as low sensitivity and improved strength, water reduction rate and slump retention, and the effect on machine-made sand is improved. The slow addition of material A and material B can increase the conversion rate of the polyether macromonomer, make the molecular conformation of the polycarboxylic acid water-reducing agent more and more extended, and at the same time increase the molecular weight of the polycarboxylic acid water-reducing agent and narrow the molecular weight distribution. The performance reaches the best within the set time, and the static paddle flow test results can meet the standards when the amount of water-reducing agent added is small, thereby improving the applicability of the mortar.

[0123] Example 6

[0124] The present application also discloses a collapse-preserving polycarboxylic acid water-reducing agent storage and powder spraying device, which is applied in step S7 of Example 1, and the water-reducing agent after pH adjustment is put into the device for storage and powder spraying.

[0125] refer to Figure 1 and Figure 2 The collapse-preserving polycarboxylic acid water-reducing agent storage powder spraying equipment comprises a kettle body 1, a reaction ring shell 8, a motor 2, a rotating rod 21, a heating plate 211, a scraper plate 5 and a feeding frame 6. The reaction ring shell 8 is provided with an opening, and is installed at the top position inside the kettle body 1. The feeding port of the kettle body 1 is located at the top, directly above the reaction ring shell 8. The space formed by the circumferential outer wall of the reaction ring shell 8 and the inner wall of the kettle body 1 is an external heating chamber 12, and the space surrounded by the circumferential inner wall of the reaction ring shell 8 is an internal heating chamber 11. A plurality of reinforcing plates 121 are fixedly provided on the inner wall of the kettle body 1, and the reinforcing plates 121 are vertically arranged and fixedly connected to the circumferential outer wall of the reaction ring shell 8. The portion of the kettle body 1 below the reaction ring shell 8 is a powder spraying area.

[0126] The motor 2 is mounted on the top of the kettle body 1, and the rotating shaft extends into the inner heating chamber 11, and the inner heating chamber 11 is provided with a speed reduction assembly 3. The rotating rod 21 is rotatably mounted in the inner heating chamber 11 and extends into the powder spraying area. The rotating rod 21 is vertically arranged and coaxially arranged with the rotating shaft of the motor 2. The speed reduction assembly 3 is connected to the rotating shaft of the motor 2 and the rotating rod 21, and is used to drive the rotating rod 21 to rotate.

[0127] The heating disc 211 is mounted at the bottom end of the rotating rod 21, and is in the shape of an umbrella that protrudes upward and is made of metal. A heating wire 4 is mounted on the inner wall of the kettle body 1 below the heating disc 211, and the heating wire 4 is arranged in a spiral. The scraper plate 5 is mounted on the inner wall of the kettle body 1, located above the heating disc 211, and is in contact with the upper surface of the heating disc 211. A nozzle 15 is installed at the bottom of the reaction ring shell 8, and the nozzle 15 is directly opposite to the heating disc 211, and the water reducer is sprayed in atomization on a partial area of ​​the heating disc 211. The scraper plate is located on the side away from the rotation direction of the heating disc 211 relative to the nozzle 15, and the scraper plate is inclined and can drain the contacted objects downward. The unloading frame 6 is arranged at the bottom of the kettle body 1, and is located below the end of the scraper plate 5, and is inclined downward and extends from the kettle body 1. The rotating shaft of the motor 2 is provided with a stirring component 7 for stirring the water reducer in the reaction ring shell 8.

[0128] The heating plate 211 is provided with an opening in the middle, and a connecting hole 212 is provided in the middle of the bottom end of the rotating rod 21, and the connecting hole 212 is connected to the inner heating chamber 11. A negative pressure hole 14 is provided on the top of the kettle body 1, and is connected to the negative pressure fan through a pipeline. In this embodiment, the inner wall of the kettle body 1 is also provided with a frame structure for stably abutting the bottom of the heating plate 211, so as to improve the stability of the heating plate 211 during rotation.

[0129] The water reducing agent is injected into the reaction ring shell 8, the motor 2 drives the rotating shaft to rotate, drives the rotating rod 21 to rotate through the speed reduction component 3, and drives the heating plate 211 to rotate through the rotating rod 21. The rotating shaft of the motor 2 also stirs the water reducing agent in the reaction ring shell 8 through the stirring component 7, thereby reducing the precipitation of the water reducing agent during the powder spraying process, and also improves the heat uniformity during the powder spraying process of the water reducing agent, thereby improving the product quality.

[0130] The water reducer in the reaction ring shell 8 is sprayed onto the reaction disk through the nozzle 15, and the water reducer on the reaction disk is dried and powdered by the heating of the heating wire 4. When the corresponding area of ​​the reaction disk rotates to abut against the scraper plate 5, the water reducer powder is scraped into the unloading frame 6 to achieve the powdering of the water reducer. The heat generated by the heating wire 4 heats the air in the powder spraying area, the inner heating chamber 11 and the outer heating chamber 12, and the efficiency of the hot air flowing into the inner heating chamber 11 and the outer heating chamber 12 is improved by the drainage of the negative pressure fan. The heat of the air heated by the heating wire 4 is used to heat the reaction ring shell 8, and the heat uniformity of the water reducer in the reaction ring shell 8 is improved by stirring, so that the water reducer in the reaction ring shell 8 is maintained in the range of 25-35°C. In this embodiment, the temperature of the water reducer is controlled at 32°C by the power of the negative pressure fan.

[0131] refer to Figure 3 and Figure 4 The reduction assembly 3 includes a first gear 31, a second gear 32 and a gear housing 33. The first gear 31 is fixed to the bottom end of the rotating shaft of the motor 2. There are multiple second gears 32, which are rotatably mounted on the circumferential inner wall of the reaction ring housing 8 and meshed with the first gear 31. The circumferential inner wall of the gear housing 33 meshes with multiple second gears 32, and the rotating shaft is fixedly connected to the lower surface of the gear housing 33. During the rotation of the rotating shaft of the motor 2, the second gear 32 is driven to rotate, and the second gear 32 drives the gear housing 33 to rotate, thereby reducing the rotation speed of the rotating rod 21, giving the water reducer on the reaction disk sufficient drying time.

[0132] refer to Figure 3The stirring assembly 7 includes an undulating ring 73, a sliding rod 71 and a rotating paddle 72. The inner side wall of the reaction ring shell 8 is fixed with a plurality of groups of positioning plates 81, and the plurality of groups of positioning plates 81 are equidistantly distributed in a circle with the axis of the rotating rod 21 as the center. There are two positioning plates 81 in each group, and they are arranged vertically. A hole is provided in the middle position of the upper surface of the positioning plate 81. The sliding rod 71 slides vertically in the holes of the two positioning plates 81 in the same group, and limits the rotation of the sliding rod 71. There are multiple rotating paddles 72, which are rotatably sleeved on the sliding rod 71, and the blades of the multiple rotating paddles 72 on the same sliding rod 71 are oriented in the same direction. Among them, some rotating paddles 72 are below the lowest positioning plate 81. The undulating ring 73 is installed on the rotating shaft of the motor 2, located above the reaction ring shell 8, and the surrounding parts of the undulating ring 73 are arranged to undulate up and down, and the circumferential outer wall of the undulating ring 73 is provided with a track groove 731. A driving rod 711 is fixedly disposed at the top of the sliding rod 71 and is slidably connected to the track groove 731 .

[0133] When the motor 2 drives the rotating shaft to rotate, the undulating ring 73 drives the sliding rod 71 to move up and down through the driving rod 711. When the sliding rod 71 moves up and down, the fluid resistance of the water reducer drives the rotating paddle 72 to rotate, thereby stirring and diffusing the water reducer to the surroundings at the same time, so that the motor 2 can drive the heating plate 211 to rotate while also stirring the water reducer in the reaction ring shell 8. The rotation of the rotating paddle 72 not only improves the uniformity of heat dispersion of the water reducer, but also effectively reduces the deposition of the water reducer during the powder spraying process.

[0134] The embodiments of this specific implementation method are all preferred embodiments of the present application, and are not intended to limit the protection scope of the present application. Therefore, all equivalent changes made based on the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A method for preparing a collapse-retaining polycarboxylate water-reducing agent, characterized in that: The steps include: S1. Preparation of chain transfer agent: Add 1-1.5 parts of mercaptoacetic acid, 6-8 parts of carbon disulfide and 15-20 parts of methanol solvent into a reaction kettle, pass nitrogen for 2 hours and then cool for 1-2 hours; Then slowly add 30-40 parts of N,N-dimethylformamide, and then add 20-25 parts of benzyl bromide, 80-100 parts of distilled water and 10-15 parts of concentrated sulfuric acid, mix, pass nitrogen for 1-2 hours, and then cool for 2-3 hours; React under nitrogen and room temperature for 8-10h; After stirring for 2 hours, the reaction solution was filtered, dried, and then recrystallized to obtain a chain transfer agent; The parts used in the chain transfer agent preparation are used alone as a ratio in this step only; S2. Prepare material A: Take 15-40 parts of acrylic acid and 30-60 parts of distilled water, stir and mix; S3, prepare material B: take 0.5-2 parts of reducing agent, 1-3 parts of chain transfer agent and 40-80 parts of distilled water, mix and stir; S4, mix 300-500 parts of unsaturated polyether macromonomer and 200-300 parts of distilled water, and stir at room temperature for 10 minutes; S5, add 10-30 parts of acrylic acid and 1-3 parts of oxidant and stir for 10 minutes; S6. Add material A and material B at the same time. After 1.5 hours, add 100-200 parts of distilled water and stir for 15 minutes. S7. Add lime milk, adjust the pH to within the range of 8-9 and then spray powder.

2. The method for preparing a collapse-retaining polycarboxylate water-reducing agent according to claim 1, characterized in that: The unsaturated polyether macromonomer is isobutylene polyethylene glycol ether, the oxidant is hydrogen peroxide, and the reducing agent is vitamin C.

3. The method for preparing a collapse-retaining polycarboxylate water-reducing agent according to claim 2, characterized in that: In step S6, the time for complete addition of material A and material B is set to 3.5 hours.

4. The method for preparing a collapse-retaining polycarboxylate water-reducing agent according to claim 2, characterized in that: In step S7, after the pH adjustment is completed, powder spraying is performed at a temperature of 25-35°C.

5. A collapse-preserving polycarboxylate water-reducing agent storage and powder spraying device, suitable for use in step S7 of claim 4, characterized in that: include Kettle body (1); The reaction ring shell (8) is provided with an upper opening and is installed at the top of the kettle body (1). The feed opening of the kettle body (1) is located at the top and above the reaction ring shell (8). The space formed by the circumferential outer wall of the reaction ring shell (8) and the inner wall of the kettle body (1) is the external heating chamber (12), and the space enclosed by the circumferential inner wall of the reaction ring shell (8) is the internal heating chamber (11); The portion of the kettle body (1) below the reaction ring shell (8) is a powder spraying area; The motor (2) is mounted on the top of the reactor body (1), the rotating shaft extends into the inner heating chamber (11) and is fixedly provided with a first gear (31), the first gear (31) is meshed with a second gear (32), the second gear (32) is mounted on the top of the inner wall of the reactor body (1), the second gear (32) is meshed with a gear housing (33), a rotating rod (21) is fixedly provided at the bottom of the gear housing (33), the rotating rod (21) is rotatably mounted in the inner heating chamber (11), and the rotating rod (21) extends into the powder spraying area; The heating plate (211) is fixedly mounted at the bottom end of the rotating rod (21) of the motor (2) and is in the shape of an umbrella protruding upwards; The heating wire (4) is arranged below the heating plate (211) in a spiral arrangement; A nozzle (15) is disposed at the bottom of the reaction ring shell (8), communicated with the interior of the reaction ring shell (8), and faces the heating plate (211); A scraper plate (5) is mounted above the heating plate (211), is in contact with the upper surface of the heating plate (211), and is located on the side of the nozzle (15) away from the rotation direction of the heating plate (211). The scraper plate is arranged at an angle and is capable of directing the contacted object downwards; The material discharge frame (6) is arranged at the bottom of the kettle body (1) and is located below the end of the scraper plate (5). It is arranged to be inclined downward and extends out from the kettle body (1).

6. The collapse-preserving polycarboxylate water-reducing agent storage and powder spraying equipment according to claim 5, characterized in that: The heating plate (211) is provided with an opening in the middle, and a communicating hole (212) is provided in the middle of the bottom end of the rotating rod (21), and the communicating hole (212) is communicated with the inner heating chamber (11).

7. The collapse-preserving polycarboxylate water-reducing agent storage and powder spraying equipment according to claim 6, characterized in that: A plurality of reinforcing plates (121) are fixedly arranged on the inner wall of the kettle body (1); the reinforcing plates (121) are arranged vertically and fixedly connected to the circumferential outer wall of the reaction ring shell (8).

8. The collapse-preserving polycarboxylate water-reducing agent storage and powder spraying equipment according to claim 6, characterized in that: A negative pressure hole (14) is provided on the top of the kettle body (1) and is connected to the negative pressure fan through a pipeline.

9. The collapse-preserving polycarboxylate water-reducing agent storage and powder spraying equipment according to claim 5, characterized in that: The inner wall of the reaction ring shell (8) is fixedly provided with a plurality of groups of positioning plates (81), each group of positioning plates (81) has two, arranged up and down, and having a hole in the middle; Two positioning plates (81) in each group are vertically slidably connected with sliding rods (71); A plurality of rotating paddles (72) are rotatably connected to the sliding rod (71); An undulating ring (73) is fixedly provided on the portion of the rotating shaft of the motor (2) inside the kettle body (1), the circumferential portion of the undulating ring (73) is arranged to undulate up and down, and a track groove (731) is provided on the circumferential outer wall of the undulating ring (73); A driving rod (711) capable of being slidably connected to the track groove (731) is fixedly disposed at the top end of the sliding rod (71).

10. The collapse-preserving polycarboxylate water-reducing agent storage and powder spraying equipment according to claim 9, characterized in that: The partially rotating paddle (72) is below the lowermost positioning plate (81).

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