Cationic polyacrylamide reaction kettle

Abstract

The utility model discloses a cationic polyacrylamide reaction kettle which comprises a premixing reaction kettle and a polymerization reaction kettle, a material feeding port, a stirrer and a material outlet are arranged on the premixing reaction kettle, the polymerization reaction kettle is a kettle body provided with a thermal insulation layer, and a feeding port, an initiator feeding port and a nitrogen inlet pipe are arranged at the top of the polymerization reaction kettle. A material outlet is formed in the bottom of the polymerization reaction kettle, the material inlet is connected with the material outlet through a material feeding pipe, one end of the nitrogen inlet pipe is connected with a nitrogen generator, the other end of the nitrogen inlet pipe is horizontally inserted into the bottom of the polymerization reaction kettle, and a plurality of self-closing nitrogen holes are formed in the nitrogen inlet pipe. According to the utility model, a monomer and a solvent are fully mixed and dissolved and then are subjected to polymerization reaction, oxygen in a reaction system is effectively eliminated through the self-closed porous nitrogen inlet pipe, the negative influence of the oxygen on the polymerization reaction is reduced, and the polymerization reaction is ensured to be carried out under more stable and controllable conditions, so that the production efficiency is improved.

Description

Technical Field

[0001] The utility model relates to a cationic polyacrylamide reaction kettle, in particular to a polymerization reaction kettle suitable for the production of cationic polyacrylamide, and belongs to the technical field of polymer compound polymerization equipment. Background Technique

[0002] Cationic polyacrylamide is an important water-soluble polymer compound with unique cationic properties. It can combine with anionic substances in water to form macromolecular complexes, thus playing the role of adsorption and flocculation. This characteristic makes it widely used in many fields, including but not limited to water treatment, papermaking, textile, oilfield, mine, etc.

[0003] The production of cationic polyacrylamide usually involves complex chemical reactions, such as copolymerization reaction, modification reaction, etc. These reactions have strict requirements on conditions such as temperature, pH value, monomer concentration, etc. At the same time, the polyacrylamide polymerization reaction is an exothermic process. Especially in aqueous solution polymerization, heat dissipation is more difficult. If the heat cannot be dissipated in time, it may cause a sharp rise in the reaction temperature, affecting the quality and performance of the polymerization product, and even leading to safety accidents. In the existing production of polyacrylamide polymerization, a single reaction kettle is usually used, that is, the reaction monomers need to be mixed and polymerized in the same reaction kettle. Therefore, in the actual production process, there are often situations such as uneven mixing of materials, incomplete deoxidation, and easy occurrence of thermal runaway in the initiation process. For this reason, it is necessary to provide a new type of cationic polyacrylamide polymerization reaction kettle for these problems.

[0004] In the prior art, in order to improve the uniformity of material mixing and the stability of equipment use, a cationic polyacrylamide reaction kettle disclosed in Chinese Patent CN217989331U can mix the solution in the reaction kettle more evenly by setting a motor and a spiral blade on the reaction kettle. At the same time, a metal frame and an impregnation layer are set, making it have the advantages of high temperature resistance, corrosion resistance, anti-degradation, and good heat transfer performance. However, this patent does not solve the problem of incomplete nitrogen deoxidation in the polymerization reaction process, and the use of structures such as a metal frame and an impregnation layer also makes the equipment structure complicated, resulting in a high equipment manufacturing cost.

[0005] In order to improve the nitrogen deoxidation efficiency in the polymerization reaction process, an oil-in-water type cationic polyacrylamide emulsion preparation device disclosed in Chinese Patent CN220861459U can make the reaction materials mix evenly by setting a stirring device in the polymerization reaction kettle. The emulsifying pump is connected at the lower end of the polymerization reaction kettle through a pipeline, and the emulsifying pump is connected to a gas-liquid mixer through a pipeline. The high mass transfer coefficient of the gas-liquid mixer can improve the nitrogen deoxidation efficiency and reduce the production time of the polyacrylamide emulsion. However, this patent is not applicable to the polymerization reaction of cationic polyacrylamide colloid. Content of the Utility Model

[0006] The utility model aims to solve a series of problems existing in the cationic polyacrylamide polymerization reaction using a single reactor, and provides a cationic polyacrylamide reactor. Through the connected premixing reactor and polymerization reactor, the monomers and solvents are fully mixed and dissolved before the polymerization reaction is carried out. Through the self-closing porous nitrogen inlet pipe, the oxygen in the reaction system is effectively removed, reducing its negative impact on the polymerization reaction, ensuring that the polymerization reaction is carried out under more stable and controllable conditions, and thus improving production efficiency.

[0007] The utility model is realized through the following technical solutions: A cationic polyacrylamide reactor, characterized in that: it includes a premixing reactor and a polymerization reactor. A material feeding port, a stirrer and a material outlet are arranged on the premixing reactor. The polymerization reactor is a reactor body provided with a heat preservation layer. An inlet port, an initiator feeding port and a nitrogen inlet pipe are arranged at the top of the polymerization reactor, and an outlet port is arranged at the bottom of the polymerization reactor. The inlet port is connected to the material outlet through a material feeding pipe. One end of the nitrogen inlet pipe is connected to a nitrogen generator, and the other end of the nitrogen inlet pipe is horizontally inserted into the bottom of the polymerization reactor, and a number of self-closing nitrogen holes are arranged on the nitrogen inlet pipe.

[0008] On the premixing reactor, the material feeding port is located at the top of the premixing reactor, the material outlet is located at the bottom of the premixing reactor, and the stirrer shaft extends downward from the top of the premixing reactor, so that the stirrer blades are arranged near the bottom of the premixing reactor.

[0009] A flow regulating valve and a centrifugal pump are arranged on the material feeding pipe.

[0010] An inlet and an outlet for connecting circulating cooling water are arranged on the heat preservation layer.

[0011] A temperature sensor is arranged on the polymerization reactor, and the temperature sensor is interlocked with the water pump of the circulating cooling water.

[0012] A pressure gauge is arranged on the polymerization reactor.

[0013] The outlet port is connected to a granulator.

[0014] Compared with the prior art, the utility model has the following advantages and beneficial effects:

[0015] (1) The utility model combines a premixing reactor and a polymerization reactor, which can premix the reaction monomers and fully dissolve them with the solvent before feeding them into the polymerization reactor for reaction. The flow regulating valve and the centrifugal pump are used to control the addition amount of the dissolved materials, and at the same time, the uniformity of the mixing of various monomers is ensured.

[0016] (2) The present utility model adopts a structural improvement of the nitrogen inlet pipe. Nitrogen enters the polymerization reactor through the self-closing nitrogen holes, which has a self-closing function to prevent the polyacrylamide after the reaction from blocking the pores. The nitrogen inlet pipe enters from the bottom of the polymerization reactor, making the nitrogen enter more fully and the oxygen replacement more thorough during the synthesis process of polyacrylamide, and improving the stability of the product reaction process.

[0017] (3) By means of uniform nitrogen charging, the present utility model reduces the initial temperature of the reaction. At the same time, the temperature during the polymerization process is controlled by circulating cooling water, which can prevent thermal runaway during the polymerization process, effectively increase the molecular weight of polyacrylamide, reduce the monomer residue, and also reduce the generation of polyacrylamide cross-linking, improving the quality stability of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a schematic structural diagram of the present utility model.

[0019] Wherein, 1 - premixing reactor, 2 - polymerization reactor, 3 - material feeding port, 4 - stirrer, 5 - material outlet, 6 - heat insulation layer, 7 - feed port, 8 - initiator feeding port, 9 - nitrogen inlet pipe, 10 - discharge port, 11 - material feed pipe, 12 - self-closing nitrogen hole, 13 - flow regulating valve, 14 - centrifugal pump, 15 - temperature sensor, 16 - pressure gauge, 17 - granulator. SPECIFIC EMBODIMENTS

[0020] The present utility model will be further described in detail below in conjunction with the embodiments, but the embodiments of the present utility model are not limited thereto.

[0021] Embodiment 1:

[0022] This embodiment relates to a cationic polyacrylamide reactor.

[0023] As Figure 1 shown in the structure, the cationic polyacrylamide reactor includes a premixing reactor 1 and a polymerization reactor 2 connected in sequence. The premixing reactor 1 is used for premixing various monomers and fully dissolving them in a solvent, and the polymerization reactor 2 is used for polymerizing the premixed materials. The two are connected through a material feed pipe 11, and a flow regulating valve 13 and a centrifugal pump 14 are arranged on the material feed pipe 11 to ensure the continuity of the polymerization reaction process.

[0024] To ensure that various monomers are premixed evenly, in this embodiment, a material feeding port 3 is provided at the top of the premixing reactor 1 to achieve the addition of various monomers and solvents. A stirrer 4 is arranged inside the premixing reactor 1 for premixing the added materials. The rotating shaft of the stirrer 4 extends downward from the top of the premixing reactor 1, so that the blades of the stirrer 4 are arranged near the bottom of the premixing reactor 1, which can achieve full mixing of the materials at the bottom of the reactor body. A material outlet 5 is provided at the bottom of the premixing reactor 1. When various monomers are mixed evenly in the premixing reactor 1 and dissolved in the solvent, the flow regulating valve 13 and the centrifugal pump 14 can be opened to send the mixed materials into the polymerization reactor 2.

[0025] As Figure 1 shown, the polymerization reactor 2 of this embodiment is a reactor body provided with a heat preservation layer 6. The top of the polymerization reactor 2 is respectively provided with a feed inlet 7 and an initiator feeding port 8. Among them, the feed inlet 7 is connected to the material feed pipe 11 to achieve communication with the premixing reactor 1. The initiator feeding port 8 is used to add an initiator into the polymerization reactor 2 to promote the polymerization reaction. The nitrogen inlet pipe 9 enters from the bottom of the reactor, and is used to introduce nitrogen into the polymerization reactor 2, which can realize the replacement of oxygen in the reactor. To ensure more thorough oxygen replacement during the polymerization reaction process, one end of the nitrogen inlet pipe 9 is connected to a nitrogen generator, and the other end of the nitrogen inlet pipe 9 is inserted horizontally into the polymerization reactor 2 from the bottom of the polymerization reactor 2, and a number of self-closing nitrogen holes 12 are arranged on the nitrogen inlet pipe 9, and the self-closing nitrogen holes 12 are arranged at equal intervals or evenly distributed on the nitrogen inlet pipe 9. The self-closing nitrogen holes 12 themselves have a self-closing function, which can prevent the polyacrylamide after the reaction from blocking the pores, ensuring that the polymerization reaction proceeds under more stable and controllable conditions, thereby improving the polymerization production efficiency.

[0026] In this embodiment, the heat preservation layer 6 of the polymerization reactor 2 uses circulating cooling water as the heat exchange medium, that is, an inlet and an outlet for connecting the circulating cooling water are arranged on the heat preservation layer 6. By controlling the flow rate of the circulating cooling water at the inlet and the outlet, the control of the reaction temperature during the polymerization reaction process can be realized, which can prevent thermal runaway during the polymerization process and improve the product quality. Further, to better realize the automatic control of the polymerization reaction process, this embodiment is also provided with a temperature sensor 15 and a pressure gauge 17 on the polymerization reactor 2. Among them, the temperature sensor 15 can be used to detect the real-time temperature of the polymerization reaction in the polymerization reactor 2 (that is, the temperature of the reaction system). By performing interlocking control on the temperature sensor 15 and the water pump of the circulating cooling water, the control of the circulating cooling water can be realized according to the temperature change of the reaction system, and the temperature control in the polymerization reactor 2 can be realized, and then the reaction process can be made more stable. The pressure gauge 17 is used to monitor the pressure change in the reactor during the polymerization process, and the pressure in the reactor can further reflect the heat change and volume change during the polymerization reaction process under closed conditions.

[0027] The cationic polyacrylamide colloid obtained after the reaction in the polymerization reactor 2 is finally sent to the granulator 17 through the discharge port 10. After granulation by the granulator 17, it enters an electrically heated drying oven for drying. When the moisture content of the colloid is reduced to 8-10%, it can be crushed into fine particles by a pair of rollers and then packaged to obtain the finished product of cationic polyacrylamide for sale.

[0028] Example 2:

[0029] This example relates to the production process using the cationic polyacrylamide reactor of Example 1, which is specifically as follows:

[0030] First, the amide monomer (AM) and cationic monomers (DMC, DAC) are metered and slowly put into the premixing reactor 1 through the material feeding port 3. Then, pure water is added in proportion, and the stirrer 4 is started. After the materials in the reactor are fully stirred and dissolved, the flow regulating valve 13 and the centrifugal pump 14 are started, and the mixed materials are transferred into the polymerization reactor 2 through the material inlet pipe 11.

[0031] The mixed materials are sent into the polymerization reactor 2 through the inlet port 7. At the same time, the nitrogen generator is started, and nitrogen with a purity of ≥99.99% is introduced into the reactor through the nitrogen inlet pipe 9 to displace the oxygen in the solution in the reactor. The nitrogen filling time is about 60 minutes. After complete nitrogen filling, an inorganic peroxide initiator prepared in advance is slowly added to the reactor through the initiator feeding port 8. When adding, pay attention to controlling the reaction temperature of the system. If the reaction temperature rises too fast and the pressure increases too fast, and there is a tendency of explosive polymerization, turn on the circulating cooling water for cooling.

[0032] The materials undergo a polymerization reaction in the polymerization reactor 2. The polymerization reaction temperature is controlled at 60-80 °C. After 6 hours of polymerization reaction, a cationic polyacrylamide colloid is obtained, which is sent out through the discharge port 10 below the reactor body. Then, the granulator 17 is used to granulate the generated cationic polyacrylamide colloid. The granulated cationic polyacrylamide is dried by an electrically heated dryer, and the dried cationic polyacrylamide is crushed to the required particle size of the product and then packaged.

[0033] The above are only the preferred embodiments of the present invention, and do not impose any form of limitation on the present invention. Any simple modification or equivalent change made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A cationic polyacrylamide reactor, characterized in that: It includes a premixing reactor (1) and a polymerization reactor (2). A material feeding port (3), a stirrer (4) and a material outlet (5) are provided on the premixing reactor (1). The polymerization reactor (2) is a kettle body provided with a heat preservation layer (6). An inlet port (7), an initiator feeding port (8) and a nitrogen inlet pipe (9) are provided at the top of the polymerization reactor (2). An outlet port (10) is provided at the bottom of the polymerization reactor (2). The inlet port (7) is connected to the material outlet (5) through a material feeding pipe (11). One end of the nitrogen inlet pipe (9) is connected to a nitrogen generator, and the other end of the nitrogen inlet pipe (9) is horizontally inserted into the bottom of the polymerization reactor (2), and a number of self-closing nitrogen holes (12) are provided on the nitrogen inlet pipe (9).

2. The cationic polyacrylamide reactor according to claim 1, wherein: On the premixing reactor (1), the material feeding port (3) is located at the top of the premixing reactor (1), the material outlet (5) is located at the bottom of the premixing reactor (1), and the stirrer shaft extends downward from the top of the premixing reactor (1) so that the stirrer blades are arranged near the bottom of the premixing reactor (1).

3. The cationic polyacrylamide reactor according to claim 1, wherein: A flow regulating valve (13) and a centrifugal pump (14) are provided on the material feeding pipe (11).

4. The cationic polyacrylamide reactor according to claim 1, characterized in that: An inlet and an outlet for connecting circulating cooling water are provided on the heat preservation layer (6).

5. The cationic polyacrylamide reactor according to claim 4, characterized in that: A temperature sensor (15) is provided on the polymerization reactor (2), and the temperature sensor (15) is interlocked with the water pump of the circulating cooling water for control.

6. The cationic polyacrylamide reactor according to claim 1, wherein: A pressure gauge (16) is provided on the polymerization reactor (2).

7. The cationic polyacrylamide reactor according to claim 1, wherein: The outlet port (10) is connected to a granulator (17).

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