A self-collecting polymerization reactor for preparing polycarboxylate water reducer and preparation method thereof

Abstract

The invention belongs to the technical field of production and preparation of building materials, and proposes a self-sampling type polymerization reactor for preparing polycarboxylic acid water reducer and a preparation method thereof, comprising a reactor body, a reactor cover, a leg, a discharge pipe, a connecting pipe, a feed port, a wall sleeve, a stirring shaft, a stirring motor, a stirring component and a self-sampling component, wherein the self-sampling component comprises a sampling plate, a sampling channel, a sampling port, a sampling transmission box, a stepping motor, a transmission mechanism, a flexible shaft piston mechanism and a sampling tube port; the preparation method comprises glucose ester, methyl allyl polyoxyethylene ether, cyclodextrin grafted maleic anhydride, modified starch ether, hydroxypropyl methyl cellulose ether, water, an initiator aqueous solution, a polysorbate aqueous solution and a mixture of propylene oxide and epichlorohydrin. The invention has reasonable design, high heating and stirring efficiency, and can automatically sample, which is conducive to improving production efficiency and production quality of polycarboxylic acid water reducer, and is suitable for large-scale promotion.

Description

Technical Field

[0001] The invention belongs to the technical field of production and preparation of building materials, and in particular relates to a self-collecting type polymerization reaction kettle for preparing a polycarboxylic acid water reducer and a preparation method thereof. Background Art

[0002] Polycarboxylate water reducer is an environmentally friendly additive used in concrete. The main functions of concrete water reducer include: 1) Improve fluidity. Water reducer can disperse cement particles, improve the workability of concrete mixture, reduce unit water consumption, and thus improve the fluidity of concrete mixture; 2) Save cement: While maintaining the fluidity of concrete, water reducer can reduce unit cement consumption and save concrete production costs; 3) Improve strength: Water reducer can increase the hardness and structural density of cement mortar, thereby increasing the strength of mortar; 4) Maintain slump: Water reducer helps maintain the slump of concrete and prevents concrete from losing fluidity during transportation and pouring.

[0003] At present, the polymerization reactor used in the preparation of polycarboxylic acid water reducer can complete the processes of stirring, titration and polymerization, but the existing polymerization reactor still has some problems in actual production. For example, in terms of sampling, the stirring process and the polymerization reaction require multiple sampling to monitor the reaction progress, but due to the high sampling pressure, in order to ensure safety, a valve group composed of multiple valves will be used, and each sampling needs to ensure a safe valve switching sequence, but this will increase the cumbersomeness of the sampling steps and the sampling efficiency is low; secondly, in terms of heating and stirring, most polymerization reactors use electric heating, steam heating or mixed heating, but because there is a certain distance between the heat and the liquid in the center of the reactor body, this will reduce the efficiency of heating and stirring, thereby affecting production efficiency. Summary of the invention

[0004] The present invention aims at the technical problems existing in the polymerization reaction process of the above-mentioned polycarboxylate water reducer, and proposes a self-sampling type polymerization reactor for preparing polycarboxylate water reducer, which has reasonable design, high heating and stirring efficiency, can automatically sample and is conducive to improving production efficiency, and a preparation method thereof.

[0005] In order to achieve the above-mentioned purpose, the technical scheme adopted by the present invention is as follows: a self-sampling type polymerization reactor for preparing polycarboxylic acid water-reducing agent and a preparation method thereof provided by the present invention include a reactor body, a reactor cover, legs and a discharge pipe are arranged on the reactor body, a plurality of connecting pipes and a feed port are arranged on the top of the reactor cover, a wall sleeve is arranged inside the reactor body, a stirring shaft is arranged at the center of the reactor body, a stirring motor connected to the stirring shaft is arranged on the top of the stirring shaft, a stirring assembly is arranged outside the stirring shaft, and the self-sampling assembly connected to the wall sleeve is arranged inside the reactor body, the self-sampling assembly includes a sampling plate, the sampling plate extends from the inside of the reactor body to the outside of the reactor body and the reactor cover to form a zigzag loop, a sampling channel is arranged inside the sampling plate, a sampling port connected to the inside of the reactor body is arranged at the bottom of the sampling channel, and the The sampling plate is provided with a sampling transmission box at a position outside the kettle body, and a stepper motor is provided on the sampling transmission box. The transmission output end of the stepper motor is provided with a transmission mechanism located inside the sampling transmission box, and the transmission side of the transmission mechanism is provided with a soft shaft piston mechanism which is transmission-connected with the transmission mechanism and cooperates with the sampling channel. A sampling tube mouth is provided on the outside of the sampling plate, and the wall sleeve includes a cylindrical section, and a conical section is provided at the bottom of the cylindrical section. A plurality of concentrically distributed annular sections are provided on the conical section. The annular section is a hollow structure and a plurality of doorways for passing water are provided at the connection position between the annular section and the conical section. The stirring assembly includes a shaft sleeve transmission-connected with the stirring shaft, and a plurality of stirring blades distributed in a circular array are provided on the side of the shaft sleeve. The stirring blades include a main board, and a plurality of support plates spaced apart from the cylindrical section are provided on the main board.

[0006] Preferably, the soft shaft piston mechanism comprises a zigzag soft shaft, which is distributed along the zigzag path of the sampling channel, and is provided with a plurality of flexible pistons spaced apart along its length direction, and the side surfaces of the flexible pistons are frictionally matched with the inner wall of the sampling channel, and the transmission mechanism comprises a transmission shaft, and the transmission shaft is provided with a thumbwheel connected to the transmission shaft, and the rim of the thumbwheel is provided with a plurality of gear teeth, and the gear teeth are provided with wheel grooves matching the soft shaft, and a through opening for the movement of the gear teeth is provided at the turning position of the sampling plate, and the length of the through opening is less than the linear length of the two gear teeth.

[0007] Preferably, a spiral protrusion extending spirally along the length direction of the flexible shaft is provided on the axial surface of the flexible shaft, and an engaging groove cooperating with the spiral protrusion is provided on the wheel groove.

[0008] Preferably, a collection tube is provided at the sample outlet end of the sampling tube mouth, and a plurality of solenoid valves spaced apart along the length direction thereof are provided on the collection tube, and a branch pipe is provided on the solenoid valve, and a sampling bottle is connected to the branch pipe via a quick connector.

[0009] Preferably, the side of the sampling plate facing the wall sleeve is a curved surface, the curved surface is in surface-to-surface fit with the inner wall of the wall sleeve, and the portion of the sampling plate extending out of the kettle cover is inclined to the kettle cover.

[0010] Preferably, the heights of the plurality of annular cylinder segments increase in sequence from the outside to the inside, and the heights of the doorways located on the annular cylinder segments increase in sequence from the outside to the inside.

[0011] Preferably, the heights of the plurality of support plates on the main board increase in sequence from the outside to the inside.

[0012] Preferably, the stirring assembly includes a spiral blade arranged on a shaft sleeve, the spiral radius of the spiral blade gradually increases from low to high, the bottom of the spiral blade is close to the bottom center direction of the kettle body, and the spiral blade is welded to the main board near its top.

[0013] Preferably, a lower supporting ring plate is provided at the bottom of the shaft sleeve, and an upper supporting ring plate is provided at the top of the shaft sleeve, and the upper supporting ring plate is welded to the spiral blades and the main board.

[0014] A method for preparing a polycarboxylate water-reducing agent comprises the following specific steps:

[0015] S1. Preparation of premixed liquid: add glucose ester, methyl allyl polyoxyethylene ether, cyclodextrin grafted maleic anhydride, modified starch ether, hydroxypropyl methyl cellulose ether and water into a batching kettle, stir and mix them evenly at room temperature, and then transfer them to a self-collecting polymerization reactor for normal pressure polymerization reaction at a temperature of 60-70° C. Samples are taken twice within 2-3 hours through the automatic sampling function of the self-collecting polymerization reactor until a premixed liquid is obtained;

[0016] S2, taking the premixed liquid obtained in S1, the initiator aqueous solution, and the polysorbate aqueous solution and adding them into the polymerization reaction kettle through different feed ports until they are stirred evenly;

[0017] S3. Add a mixture of propylene oxide and epichlorohydrin, continue stirring, adjust the reaction pressure to 1-2 MPa, adjust the pH to 5-7, react for 2 hours, and take samples at least 3 times within 2-3 hours of the subsequent reaction through the automatic sampling function of the self-sampling polymerization reactor, with an interval of not less than half an hour, until the polycarboxylate water reducer is obtained.

[0018] Compared with the prior art, the advantages and positive effects of the present invention are:

[0019] 1. The present invention provides a self-sampling type polymerization reactor for preparing polycarboxylic acid water-reducing agent. The self-sampling component can automatically sample during the reaction process of the polymerization reactor without manually adjusting multiple valves, which can ensure sampling efficiency and improve sampling safety. The sampling timing is flexible, which is conducive to improving production efficiency. The annular barrel section of the wall sleeve can improve the heat exchange efficiency with the center of the reactant, and matching it, the stirring component can stir the reactants between adjacent annular barrel sections, which is conducive to improving the production efficiency of the reactants and can also save costs to a certain extent. The present invention has a reasonable design, high heating and stirring efficiency, can automatically sample and is conducive to improving production efficiency, and is suitable for large-scale promotion.

[0020] 2. The present invention provides a method for preparing a polycarboxylate water reducer. By adopting a self-sampling polymerization reactor to participate in the polymerization, titration, heating and stirring processes of the polycarboxylate water reducer, the polycarboxylate water reducer can be automatically sampled at different time points, which is beneficial to improving the production efficiency and the quality of the polycarboxylate water reducer. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0022] Figure 1 It is a cross-sectional view of a self-collecting type polymerization reactor for preparing a polycarboxylate water-reducing agent in the GG direction;

[0023] Figure 2 It is a front view of a self-collecting polymerization reactor for preparing polycarboxylate water-reducing agent;

[0024] Figure 3 The isometric view of a self-collecting polymerization reactor for preparing a polycarboxylate water-reducing agent;

[0025] Figure 4 A schematic diagram of the internal structure of a self-collecting polymerization reactor for preparing a polycarboxylate water-reducing agent;

[0026] Figure 5 is a front view of the stirring assembly;

[0027] Figure 6 It is an expanded top view of the transmission mechanism and the flexible shaft piston mechanism;

[0028] Figure 7 It is the expanded axonometric drawing of the transmission mechanism and the flexible shaft piston mechanism;

[0029] In the above figures, 1, kettle body; 2, kettle cover; 3, wall sleeve; 31, column section; 32, cone section; 33, annular section; 34, door; 4, stirring shaft; 5, stirring motor; 6, stirring assembly; 61, shaft sleeve; 62, stirring blade; 621, main board; 622, support plate; 63, spiral blade; 64, lower support ring plate; 65, upper support ring plate; 7, self-sampling assembly; 71, sampling plate; 72, sampling channel ; 73. Sampling port; 74. Sampling transmission box; 75. Stepper motor; 76. Transmission mechanism; 761. Transmission shaft; 762. Pulley; 763. Gear teeth; 764. Gear groove; 765. Engaging groove; 77. Soft shaft piston mechanism; 771. Soft shaft; 772. Flexible piston; 773. Spiral protrusion; 78. Sampling tube mouth; 79. Collection tube; 710. Solenoid valve; 711. Branch pipe; 712. Sampling bottle. DETAILED DESCRIPTION

[0030] In order to more clearly understand the above-mentioned objects, features and advantages of the present invention, the present invention is further described below in conjunction with the accompanying drawings and embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict. For the convenience of description, if the words "upper", "lower", "left" and "right" appear below, they only indicate that the upper, lower, left and right directions are consistent with the accompanying drawings themselves, and do not limit the structure.

[0031] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways than those described herein. Therefore, the present invention is not limited to the specific embodiments of the following disclosure.

[0032] Examples, such as Figure 1 As shown in FIG. 7 , the present invention provides a self-sampling polymerization reactor for preparing polycarboxylic acid water-reducing agent, comprising a reactor body 1, on which a reactor cover 2, legs and a discharge pipe are arranged, a plurality of connecting pipes and a feed port are arranged on the top of the reactor cover 2, a wall sleeve 3 is arranged inside the reactor body 1, a stirring shaft 4 is arranged at the center of the reactor body 1, a stirring motor 5 connected to the stirring shaft 4 is arranged on the top of the stirring shaft 4, and a stirring assembly 6 is arranged outside the stirring shaft 4. Among them, the connecting pipe is used to connect different feeding pipes, pressure pipes, burettes and required detection components, and the feed port can be used to add water and other materials. The reactor body 1, the reactor cover 2, legs, the discharge pipe, the stirring shaft 4 and the stirring motor 5 are prior art, and this embodiment will not be repeated here. On this basis, the present invention proposes improvements to the wall sleeve 3 and the stirring assembly 6 to improve the efficiency of heating and stirring, and also designs a self-sampling assembly 7 for automatic sampling to improve the efficiency of sampling and timely detect the production status of the reactants.

[0033] Specifically, the interior of the kettle body 1 provided by the present invention is provided with a self-sampling component 7 connected to the wall sleeve 3, and the self-sampling component 7 includes a sampling plate 71, and the sampling plate 71 extends from the interior of the kettle body 1 to the outside of the kettle body 1 and the kettle cover 2 to form a zigzag loop. The interior of the sampling plate 71 is provided with a sampling channel 72, and the bottom of the sampling channel 72 is provided with a sampling port 73 connected to the interior of the kettle body 1. The sampling port 73 can be designed to be strip-shaped to ensure a certain sampling distance, so that the soft shaft piston mechanism 77 can collect the corresponding liquid. The sampling plate 71 is provided with a sampling transmission box 74 at a position located outside the kettle body 1, and a stepping motor 75 is provided on the sampling transmission box 74. The transmission output end of the stepping motor 75 is provided with a transmission mechanism 76 located inside the sampling transmission box 74, and the transmission side of the transmission mechanism 76 is provided with a soft shaft piston mechanism 77 that is transmission-connected to it and cooperates with the sampling channel 72, and the sampling plate 71 is provided with a sampling tube port 78 outside. Wherein, the bottom of the sampling plate 71 can be immersed in the reactant liquid, and the sampling port 73 is immersed in the reactant liquid. The stepper motor 75 can make the flexible shaft piston mechanism 77 move in the sampling channel 72 by inputting power to the transmission mechanism 76, and the flexible shaft piston mechanism 77 can squeeze part of the liquid into the sampling channel 72 when passing through the sampling port 73, and the sucked liquid is moved to the sampling tube mouth 78 position in the sampling channel 72 by the continued movement of the flexible shaft piston mechanism 77, and the reactant liquid is discharged from the sampling tube mouth 78. At the same time, due to the active sealing effect of the flexible shaft piston mechanism 77 in the sampling channel 72, the pressure inside the kettle body 1 can be avoided to be relatively large, and automatic sampling can be completed under safe conditions. In this way, the self-sampling component 7 can automatically sample in the reaction process of the polymerization reactor, without manually adjusting multiple valves, which can not only ensure sampling efficiency, but also improve sampling safety, and the sampling timing is flexible, which is conducive to improving production efficiency.

[0034] Furthermore, the wall sleeve 3 includes a column section 31, a conical section 32 is provided at the bottom of the column section 31, and a plurality of concentrically distributed annular sections 33 are provided on the conical section 32. The annular section 33 is a hollow structure and a plurality of water-passing doors 34 are provided at the connection position with the conical section 32. The stirring assembly 6 includes a sleeve 61 connected to the stirring shaft 4 in a transmission manner, and a plurality of stirring blades 62 distributed in a circular array are provided on the side of the sleeve 61. The stirring blades 62 include a main board 621, and a plurality of support plates 622 spaced apart from the cylindrical section are provided on the main board 621. Among them, the column section 31 can exchange heat with the liquid near the column section 31 in the kettle body 1, and a plurality of annular sections 33 extend in sections to the inside of the liquid, shortening the distance of heat exchange between the liquid and the wall sleeve 3, and improving the heat exchange efficiency between the heat and the center of the reactants. Matching the heating characteristics of the wall sleeve 3, the stirring assembly 6 stirs the reactants between adjacent annular barrel sections 33 through the main board 621 and the support plate 622, which is beneficial to improving the production efficiency of the reactants. The maximum height of the annular barrel section 33 is about 1 / 2 of the kettle body 1, so the upper half of the reactant liquid can be fully mixed and effectively collided, and for the lower half of the reactant liquid, the liquid can be exchanged and collided through the position of the door 34 under the stirring power, and most of the liquid can finally be discharged through the discharge pipe without being retained between adjacent annular barrel sections 33. Since the heating and stirring efficiency of the polymerization reactor is improved, it can also play a role in saving costs to a certain extent, such as saving time costs and heating steam costs.

[0035] In order to improve the automatic sampling efficiency of the present invention, the soft shaft piston mechanism 77 is used as a component for performing sampling, which specifically includes a zigzag soft shaft 771, which is distributed along the zigzag path of the sampling channel 72, and is provided with a plurality of flexible pistons 772 spaced apart along its length direction. The side of the flexible piston 772 is frictionally matched with the inner wall of the sampling channel 72. The transmission mechanism 76 includes a transmission shaft 761, and a thumbwheel 762 is provided on the transmission shaft 761 for transmission connection therewith. The rim of the thumbwheel 762 is provided with a plurality of gear teeth 763, and the gear teeth 763 are provided with wheel grooves 764 that cooperate with the soft shaft 771. A through opening for the gear teeth 763 to move is provided at the turning position of the sampling plate 71, and the length of the through opening is less than the linear length of the two gear teeth 763. Among them, the sampling channel 72 adopts a circular cross-section design, which can generate sliding friction with the piston surface of the flexible piston 772, but can perform corresponding creeping under the action of tension, and can be bent at a certain angle at the path turning point of the sampling plate 71 to ensure continuous and effective movement, so as to carry a certain volume of reactant liquid. The stepper motor 75 is used to drive the transmission shaft 761 and the dial wheel 762. When the dial wheel 762 rotates, the gear 763 can dial the flexible piston 772 entering the tooth groove, and the flexible shaft 771 is driven with the wheel groove 764. The reactant liquid carried between adjacent flexible pistons 772 can be discharged from the sampling port before contacting the dial wheel 762, and the dial wheel 762 is used to continuously drive the flexible shaft piston mechanism 77 to inhale the reactant liquid until the sampling volume of the reactant liquid meets the sampling requirements. For the excess liquid in the sampling channel 72, the flexible shaft piston mechanism 77 is turned back to the interior of the kettle body 1 by reversing the dial wheel 762 before the next sampling, and then rotated forward to sample, thereby reducing the error between the sample sampled at that time and the reactant liquid at that time. The design of the through-port on the sampling plate 71 is to ensure that the sampled liquid does not contact the dial wheel 762 in advance before being discharged from the sampling tube port 78, and to ensure that the sampled liquid carried by the flexible piston 772 has sufficient pressure to be discharged, so as not to leak into the sampling transmission box 74 over a large area.

[0036] In order to improve the sampling efficiency, the axial surface of the flexible shaft 771 provided by the present invention is provided with a spiral protrusion 773 extending spirally along the length direction thereof, and the wheel groove 764 is provided with an engagement groove 765 cooperating with the spiral protrusion 773. In this way, in addition to the wheel groove 764 having the function of preventing the axial side of the flexible shaft 771 from running off, the transmission accuracy of the dial wheel 762 to the flexible shaft 771 can be improved through the transmission of the engagement groove 765 and the spiral protrusion 773, and the moving efficiency of the flexible shaft piston mechanism 77 in the sampling channel 72 can be improved, thereby ensuring the sampling controllability of the self-sampling component 7.

[0037] In order to ensure the flexibility of the sampling timing of the self-sampling component 7, the sampling end of the sampling tube mouth 78 provided by the present invention is provided with a collection tube 79, and the collection tube 79 is provided with a plurality of electromagnetic valves 710 spaced along the length direction thereof, and the electromagnetic valve 710 is provided with a branch pipe 711, and the branch pipe 711 is connected with a sampling bottle 712 through a quick connector. Among them, the electromagnetic valve 710 is used to control the on-off status of the branch pipe 711, so that the sampling bottles 712 on different branches do not affect each other, and reduce the influence of the reaction pressure of the polymerization reactor on the quick-connect sampling bottle 712. In this way, at different reaction times of the polymerization reactor, by starting different electromagnetic valves 710, the reactant liquid at that time can enter the corresponding sampling bottle 712, and as the stepping motor 75 stops the sampling action, the corresponding electromagnetic valve 710 is also closed, and the sampling bottle 712 obtained by the sample can be safely removed, eliminating the workload of manually adjusting multiple valves, simplifying the sampling work, and helping to improve production efficiency.

[0038] Considering that the arrangement depth of the sampling plate 71 and the stirring depth of the stirring assembly 6 have a certain overlap, and considering the safety of the sampling plate 71, and considering the installation requirements of the sampling plate 71 and the wall sleeve 3, the side of the sampling plate 71 provided by the present invention facing the wall sleeve 3 is a curved surface, and the curved surface is in surface-to-surface cooperation with the inner wall of the wall sleeve 3. In this way, the sampling plate 71 can be close to the wall sleeve 3, and the other side thereof is kept at a certain distance from the support plate 622 of the stirring assembly 6, so that the sampling port 73 can be ensured to be at a reasonable sampling depth position, and the safe stirring performance of the stirring assembly 6 can be ensured. At the same time, the part of the sampling plate 71 extending out of the kettle cover 2 is arranged at an angle with the kettle cover 2, so that it is convenient to arrange structures such as the stepping motor 75 and the collection tube 79, which is conducive to improving the spatial coordination effect of the self-sampling assembly 7, and improving the space utilization rate and self-sampling performance of the equipment.

[0039] In order to improve the heating efficiency inside the polymerization reactor, the heights of the plurality of annular barrel sections 33 provided by the present invention are successively increased from the outside to the inside, so that the heat exchange efficiency with the liquid near the center of the reactor body 1 can be improved. Matching this, the heights of the doorways 34 located on the annular barrel sections 33 are successively increased from the outside to the inside, so that sufficient exchange space between the liquids can be ensured, and it is beneficial for the liquid to be discharged from the discharge pipe, thereby avoiding the retention of materials in the reactor body 1.

[0040] In order to improve the coordination effect between the stirring assembly 6 and the wall sleeve 3, the heights of the multiple support plates 622 located on the main board 621 of the present invention are successively increased from the outside to the inside, so that the liquid between adjacent annular sections 33 can be fully stirred and the force uniformity of the stirring shaft 4 can be improved.

[0041] In order to improve the stirring efficiency of the material, the stirring assembly 6 of the present invention includes a spiral blade 63 arranged on the shaft sleeve 61, the spiral radius of the spiral blade 63 gradually increases from low to high, the bottom of the spiral blade 63 is close to the bottom center direction of the kettle body 1, and the position of the spiral blade 63 close to its top is welded to the main board 621. In this way, for the liquid located at the center of the kettle body 1, especially the liquid within the range of the innermost annular cylinder section 33, the continuous rotation of the spiral blade 63 can bring part of the liquid to a high place and then mix and stir with the liquid at other positions, which is conducive to improving the circulation effect and mixing quality of the liquid inside the entire kettle body 1.

[0042] In order to improve the structural strength of the stirring assembly 6, the present invention is provided with a lower support ring plate 64 at the bottom of the shaft sleeve 61, and an upper support ring plate 65 is provided at the top of the shaft sleeve 61, and the upper support ring plate 65 is welded to the spiral blade 63 and the main board 621. The upper support ring plate 65 can provide a welding foundation for the main board 621 and the spiral blade 63, which is conducive to improving the structural strength of the stirring assembly 6; the lower support ring plate 64 can cooperate with the support member at the bottom of the kettle body 1, and the support member position can be arranged with a bearing bush or a bearing to improve the synchronous rotation quality of the stirring assembly 6 and the stirring shaft 4.

[0043] A method for preparing a polycarboxylate water-reducing agent comprises the following specific steps:

[0044] S1. Preparation of premixed liquid: add glucose ester, methyl allyl polyoxyethylene ether, cyclodextrin grafted maleic anhydride, modified starch ether, hydroxypropyl methyl cellulose ether and water into a batching kettle, stir and mix them evenly at room temperature, and then transfer them to a self-collecting polymerization reactor for normal pressure polymerization reaction at a temperature of 60-70° C. Sampling is performed twice within 2-3 hours by the automatic sampling function of the self-collecting polymerization reactor until a premixed liquid is obtained; the modified starch ether is obtained by mixing starch, an alkalizing agent, an alcohol and an alkali metal salt, adding a premix of sodium chloroacetate, propylene oxide and epichlorohydrin, and stirring for reaction;

[0045] S2, taking the premixed liquid obtained in S1, the initiator aqueous solution, and the polysorbate aqueous solution and adding them into the polymerization reaction kettle through different feed ports until they are stirred evenly;

[0046] S3. Add a mixture of propylene oxide and epichlorohydrin, continue stirring, adjust the reaction pressure to 1-2 MPa, adjust the pH to 5-7, react for 2 hours, and take samples at least 3 times within 2-3 hours of the subsequent reaction through the automatic sampling function of the self-sampling polymerization reactor, with an interval of not less than half an hour, until the polycarboxylate water reducer is obtained.

[0047] By using a self-collecting polymerization reactor to participate in the polymerization, titration, heating and stirring processes of the polycarboxylate water reducer, the polycarboxylate water reducer can be automatically sampled at different time points. The sampling timing of the automatic sampling is flexible and the sampling safety is relatively high. The sampling means is combined with the reaction control means of the self-collecting polymerization reactor, and the next control process can be entered in time after the sampling sample meets the standard, which is beneficial to improving the production efficiency and the quality of the polycarboxylate water reducer.

[0048] Furthermore, the modified starch ether improves the water retention of the water reducer by introducing multiple hydrophilic groups, thereby improving the performance of the concrete; and, by using methyl allyl polyoxyethylene ether modified monomers, polysorbates are introduced to control chain transfer, and water-retaining materials such as modified starch ether, hydroxypropyl methylcellulose ether, polyacrylamide, glucose ester, and polyhydroxy phosphate undergo cross-linking reactions to form a rotating structure, thereby increasing the resistance of the concrete adsorption structure, ensuring that the cementitious materials in the concrete are not prone to agglomeration, significantly improving the water retention of the product, and improving the workability of the concrete. The concrete can maintain good fluidity and pumpability for a long time, avoiding sedimentation and bleeding. By grafting maleic anhydride with cyclodextrin, the water retention is further improved in a synergistic manner, which is beneficial to improving the performance of the concrete.

[0049] The above description is only a preferred embodiment of the present invention and does not limit the present invention in other forms. Any technician familiar with the profession may use the technical content disclosed above to change or modify it into an equivalent embodiment with equivalent changes and apply it to other fields. However, any simple modification, equivalent change and modification made to the above embodiment based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A self-feeding polymerization reactor for preparing polycarboxylate water-reducing agent, comprising a reactor body, a reactor cover, legs and a discharge pipe are arranged on the reactor body, a plurality of connecting pipes and a feed port are arranged on the top of the reactor cover, a wall sleeve is arranged inside the reactor body, a stirring shaft is arranged at the center of the reactor body, a stirring motor connected to the stirring shaft is arranged on the top of the stirring shaft, and a stirring assembly is arranged outside the stirring shaft, characterized in that: The interior of the kettle body is provided with a self-sampling component connected with the wall sleeve, and the self-sampling component includes a sampling plate, and the sampling plate extends from the interior of the kettle body to the outside of the kettle body and the kettle cover to form a zigzag loop, and the interior of the sampling plate is provided with a sampling channel, and the bottom of the sampling channel is provided with a sampling port connected with the interior of the kettle body, and the sampling plate is provided with a sampling transmission box at a position outside the kettle body, and a stepper motor is provided on the sampling transmission box, and a transmission mechanism located inside the sampling transmission box is provided at the transmission output end of the stepper motor, and a transmission side of the transmission mechanism is provided with a transmission mechanism connected with the transmission mechanism. The invention relates to a soft shaft piston mechanism which is dynamically connected and cooperates with the sampling channel, the sampling plate is provided with a sampling tube mouth on the outside, the wall sleeve comprises a cylindrical section, the bottom of the cylindrical section is provided with a conical section, the conical section is provided with a plurality of concentrically distributed annular sections, the annular section is a hollow structure and a plurality of water-passing openings are provided at the connection position between the annular section and the conical section, the stirring assembly comprises a shaft sleeve which is transmission-connected to the stirring shaft, a plurality of stirring blades distributed in a circular array are provided on the side of the shaft sleeve, the stirring blades comprise a main board, a plurality of support plates which are spaced apart from the cylindrical section are provided on the main board.

2. The self-collecting polymerization reactor for preparing polycarboxylate water-reducing agent according to claim 1, characterized in that: The flexible shaft piston mechanism comprises a zigzag flexible shaft, which is distributed along the zigzag path of the sampling channel, and is provided with a plurality of flexible pistons which are spaced apart along its length direction, and the side surface of the flexible piston is frictionally matched with the inner wall of the sampling channel, and the transmission mechanism comprises a transmission shaft, and is provided with a thumbwheel which is transmission-connected thereto, and the thumbwheel has a plurality of gear teeth on its rim, and the gear teeth are provided with wheel grooves which match the flexible shaft, and a through opening for the gear teeth to move is provided at the turning position of the sampling plate, and the length of the through opening is less than the linear length of the two gear teeth.

3. The self-collecting polymerization reactor for preparing polycarboxylate water-reducing agent according to claim 2, characterized in that: A spiral protrusion extending spirally along the length direction of the flexible shaft is arranged on the axial surface of the flexible shaft, and an engaging groove matched with the spiral protrusion is arranged on the wheel groove.

4. A self-collecting polymerization reactor for preparing a polycarboxylate water-reducing agent according to claim 1 or 3, characterized in that: A collection tube is provided at the sample outlet end of the sampling tube port, and a plurality of electromagnetic valves are provided on the collection tube and spaced apart along the length direction thereof. A branch pipe is provided on the electromagnetic valve, and a sampling bottle is connected to the branch pipe via a quick connector.

5. The self-collecting polymerization reactor for preparing polycarboxylate water-reducing agent according to claim 1, characterized in that: The side of the sampling plate facing the wall sleeve is a curved surface, and the curved surface is matched with the inner wall of the wall sleeve in a surface-to-surface manner. The portion of the sampling plate extending out of the kettle cover is arranged in an inclined manner with the kettle cover.

6. The self-collecting polymerization reactor for preparing polycarboxylate water-reducing agent according to claim 1, characterized in that: The heights of the plurality of annular cylinder segments increase in sequence from the outside to the inside, and the heights of the doorways located on the annular cylinder segments increase in sequence from the outside to the inside.

7. The self-collecting polymerization reactor for preparing polycarboxylate water-reducing agent according to claim 6, characterized in that: The heights of the plurality of support plates on the main board increase in sequence from the outside to the inside.

8. The self-collecting polymerization reactor for preparing polycarboxylate water-reducing agent according to claim 7, characterized in that: The stirring assembly includes a spiral blade arranged on a shaft sleeve, the spiral radius of the spiral blade gradually increases from low to high, the bottom of the spiral blade is close to the bottom center direction of the kettle body, and the spiral blade is welded to the main board near its top.

9. The self-collecting polymerization reactor for preparing polycarboxylate water-reducing agent according to claim 8, characterized in that: A lower supporting ring plate is arranged at the bottom of the shaft sleeve, and an upper supporting ring plate is arranged at the top of the shaft sleeve. The upper supporting ring plate is welded to the spiral blade and the main plate.

10. A method for preparing a polycarboxylate water-reducing agent, characterized in that: The specific steps include: S1. Preparation of premixed liquid: add glucose ester, methyl allyl polyoxyethylene ether, cyclodextrin grafted maleic anhydride, modified starch ether, hydroxypropyl methyl cellulose ether and water into a batching kettle, stir and mix them evenly at room temperature, and then transfer them into a self-collecting polymerization reactor for preparing a polycarboxylate water reducer as claimed in any one of claims 1 to 3 to carry out polymerization reaction at normal pressure at a temperature of 60 to 70° C., and sample twice within 2 to 3 hours through the automatic sampling function of the self-collecting polymerization reactor for preparing a polycarboxylate water reducer as claimed in any one of claims 1 to 3 until a premixed liquid is obtained; S2, taking the premixed liquid obtained in S1, the initiator aqueous solution, and the polysorbate aqueous solution and adding them into a self-feeding polymerization reaction kettle for preparing a polycarboxylate water-reducing agent according to any one of claims 1 to 3 through different feed ports until they are stirred evenly; S3. Add a mixture of propylene oxide and epichlorohydrin, continue stirring, adjust the reaction pressure to 1-2 MPa, adjust the pH to 5-7, react for 2 hours, and within 2-3 hours of the subsequent reaction, use the automatic sampling function of the self-sampling type polymerization reactor for preparing a polycarboxylic acid water-reducing agent as described in any one of claims 1 to 3 to take samples at least 3 times, with an interval of not less than half an hour, until the polycarboxylic acid water-reducing agent is obtained.

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