CN218893770U

CN218893770U - Acrylonitrile-acrylic acid polymer dissolving equipment

Info

Publication number: CN218893770U
Application number: CN202222850266.8U
Authority: CN
Inventors: 武兴栋; 杜球; 刘勇; 成强; 赵明
Original assignee: China Petroleum and Chemical Corp; Qilu Petrochemical Co of Sinopec
Current assignee: China Petroleum and Chemical Corp; Qilu Petrochemical Co of Sinopec
Priority date: 2022-10-27
Filing date: 2022-10-27
Publication date: 2023-04-21
Anticipated expiration: 2032-10-27

Abstract

The utility model belongs to the technical field of equipment for acrylic fiber spinning, and particularly relates to acrylonitrile-acrylic acid polymer dissolving equipment. An acrylonitrile-acrylic acid polymer dissolving apparatus characterized in that: the device comprises a stock solution mixing tank 1, wherein the stock solution mixing tank 1 comprises a shell 4 and a preparation cavity 13, and the shell 4 is provided with a stock solution inlet 2, a stock solution outlet 9 and a cylinder cover 14; the inside of the stock solution mixing tank 1 is provided with a stirring assembly 3, the stirring assembly 3 comprises a stirring rod 12, the stirring rod 12 is connected with a stirring paddle 5 and a grinding plate 11, the outer layer of the shell 4 is provided with a jacket 7, and the jacket 7 is provided with a jacket inlet 8, a jacket water outlet 6 and a jacket outlet 10; a thermometer 15 is arranged on the jacket water outlet 6. The utility model provides an acrylonitrile-acrylic acid polymer dissolving device which can reduce uneven mixing in the process of preparing stock solution and improve the high solid content of the product quality and the working efficiency.

Description

Acrylonitrile-acrylic acid polymer dissolving equipment

Technical Field

The utility model belongs to the technical field of equipment for acrylic fiber spinning, and particularly relates to acrylonitrile-acrylic acid polymer dissolving equipment.

Background

The dry polyacrylonitrile powder for dry acrylic fiber spinning is prepared by polymerization reaction with acrylonitrile, methyl acrylate and sodium styrene sulfonate as comonomer. The dry spinning process of polyacrylonitrile is to dissolve the dry polyacrylonitrile powder obtained after polymerization in organic solvent Dimethylformamide (DMF) or Dimethylacetamide (DMAC) to form spinning solution with solid content of 30-33%, and to convey the spinning solution to spinning channel and to eliminate solvent with hot nitrogen to form primary polyacrylonitrile filament. The dry spinning forming process is mild, the internal structure of the fiber is uniform, so that the dry spinning fiber has good physical and mechanical properties and dyeing properties, and the spinning section strength is good.

When a large number of hydrophilic groups such as-OH, -NH 3, -COOH and-CONH are introduced into the molecular chain of the polyacrylonitrile fiber, the moisture absorption and release performances are obviously improved, so that the hydrophilic groups are introduced into the polyacrylonitrile fiber to well play a role in temperature and humidity adjustment. The polyacrylonitrile fiber can also be used as an ion exchange fiber to further develop a new functional material with certain characteristics. However, the introduction of the hydrophilic group can cause the solubility of polyacrylonitrile in the dry acrylic solvent to be poor, when the novel polyacrylonitrile product of acrylonitrile-acrylic acid with the hydrophilic group is introduced, the phenomenon of white core is often generated in the preparation process of industrial dry spinning dope, the outer surface of the clustered white core is swelled, the powder in the inside is wrapped, the solvent is prevented from diffusing into the inside, the powder in the inside cannot be swelled and dissolved, and the change of solution viscosity is uncontrollable, so that the phenomena of yarn doubling or yarn breakage and the like occur in the spinning process.

Disclosure of Invention

The utility model aims to overcome the defects in the prior art, and provides an acrylonitrile-acrylic acid polymer dissolving device which can reduce uneven mixing in the process of preparing stock solution and improve the high solid content of the product quality and the working efficiency.

The utility model is realized by adopting the following technical scheme:

the preparation device of the polyacrylonitrile spinning solution comprises a solution mixing tank, wherein the solution mixing tank comprises a shell and a preparation cavity, and the shell is provided with a solution inlet, a solution outlet and a cylinder cover; a stirring assembly is arranged in the stock solution mixing tank and comprises a stirring rod, and a stirring paddle and a grinding plate are connected to the stirring rod; the outer layer of the shell is provided with a jacket, and the jacket is provided with a jacket inlet, a jacket water outlet and a jacket outlet; a thermometer is arranged on the jacket water outlet.

The stirring paddle adopts a hoop to be fixedly connected with the stirring rod through a bolt.

The grinding plate is anchor-type, and is fixed with the stirring rod by adopting a hoop through bolts.

The stirring paddles are downward-pressing inclined blade paddles, and the stirring rod is connected with an upper group of stirring paddles, a middle group of stirring paddles and a lower group of stirring paddles which are arranged in a cross manner; the lower parts of the upper stirring paddles and the middle stirring paddles are provided with grinding plates, and the lower parts and the side edges of the stirring paddles are of a zigzag structure; the grinding plate is of an inverted saw-tooth structure and can be overlapped with the stirring paddle up and down, namely, the grinding plate is arranged right below the stirring paddle and has a gap smaller than 1mm with the stirring paddle, and the grinding plate is fixed with the inner wall of the stock solution mixing tank and does not rotate along with the stirring rod. The stirring paddle is fastened on the stirring rod by a hoop and is fixed by a bolt. The grinding plate is fastened on the stirring rod by a hoop and is fixed by a bolt.

Specifically, the preparation method of the polyacrylonitrile spinning solution comprises the following steps:

(1) The solvent N, N-dimethylacetamide is heated to 65-85 ℃ and then enters a Mark mixer together with polyacrylonitrile powder for swelling; the mass ratio of the N, N-dimethylacetamide to the polyacrylonitrile is (69-75): (25-31);

(2) Mixing and swelling, then entering a stock solution mixing tank, introducing inert gas, evacuating and deoxidizing, stirring and dissolving for 4-16 hours at 30-80 rpm to prepare spinning stock solution with the solid content of 26-30%;

(3) After the spinning solution is filtered and refined, dry spinning is carried out in a spinning channel through a metering pump and a spinneret plate to obtain nascent fibers; the channel atmosphere is any one or more of nitrogen, ammonia, carbon dioxide, argon and the like, the channel temperature is 150-300 ℃, the channel draft multiple is 2-10, and the residence time is 1-30 s.

The preparation method of the polyacrylonitrile spinning solution comprises the following steps:

(1) After the temperature of the solvent rises, the solvent and the polyacrylonitrile powder synchronously enter a mixing device to be swelled;

(2) Mixing and swelling, and then entering a stock solution mixing tank, stirring and dissolving to prepare spinning stock solution;

application: and (3) after the filtering and refining treatment of the spinning solution, performing dry spinning in a spinning channel through a metering pump and a spinneret plate to obtain the nascent fiber.

The solvent is N, N-dimethylacetamide, and the mass ratio of the N, N-dimethylacetamide to polyacrylonitrile is (69-75): (25-31).

The temperature of the N, N-dimethylacetamide is raised to 65-85 ℃, preferably 75-79 ℃.

The solid content of the spinning solution in the step (2) is 26-30%.

The stirring speed of the step (2) is 30 to 80 rpm, preferably 40 to 70 rpm, more preferably 50 to 60 rpm, and the dissolution time is 4 to 16 hours, preferably 6 to 13 hours, more preferably 8 to 10 hours.

The channel atmosphere in application is one or more of nitrogen, ammonia, carbon dioxide, argon and the like, preferably nitrogen; the channel temperature is 150-300 ℃, the channel draft multiple is 2-10, and the residence time is 1-30 s.

The mixing device in the step (1) is a Mark mixer.

The prepared polyacrylonitrile spinning solution has acrylonitrile content of 90-100% and acrylic acid mass content of 0-10%. Wherein the rotational viscosity of the polyacrylonitrile powder is 50000-80000 mPa.s, and the number average molecular weight is 2-4 ten thousand.

The beneficial effects of the utility model are as follows:

the preparation device of the polyacrylonitrile spinning solution has good solubility of the polyacrylonitrile powder, does not have the phenomenon of white core, greatly reduces the phenomena of broken ends or doubling in the spinning process, and improves the production efficiency.

Drawings

FIG. 1 is a schematic diagram of a preparation device of an acrylonitrile-acrylic acid binary copolymer spinning solution;

FIG. 2 is a schematic view of a stirring assembly of the stock solution mixing tank of the present utility model;

in the figure: 1. a stock solution mixing tank; 2. a stock solution inlet; 3. a stirring assembly; 4. a housing; 5. stirring paddles; 6. a jacket water outlet; 7. a jacket; 8. a jacket inlet; 9. a stock solution outlet; 10. a jacket outlet; 11. a grinding plate; 12. a stirring rod; 13. preparing a cavity; 14. a cylinder cover; 5. a thermometer.

Detailed Description

The utility model is further described below with reference to the accompanying drawings.

As shown in fig. 1, the preparation device of the polyacrylonitrile spinning solution comprises a solution mixing tank 1, wherein the solution mixing tank 1 comprises a shell 4 and a preparation cavity 13, and the shell 4 is provided with a solution inlet 2, a solution outlet 9 and a cylinder cover 14; the inside of the stock solution mixing tank 1 is provided with a stirring assembly 3, the stirring assembly 3 comprises a stirring rod 12, and the stirring rod 12 is connected with a stirring paddle 5 and a grinding plate 11; the outer layer of the shell 4 is provided with a jacket 7, and the jacket 7 is provided with a jacket inlet 8, a jacket water outlet 6 and a jacket outlet 10; a thermometer 15 is arranged on the jacket water outlet 6.

The stirring paddle 5 is fixedly connected with the stirring rod 12 through bolts by adopting a hoop.

The grinding plate 11 is anchor-type and is fastened to the stirring rod 12 by bolts using a collar.

Preparation of polymer dry powder:

adding a comonomer into a polymerization kettle according to the proportion of acrylonitrile=95 and acrylic acid=5 in parts by weight, simultaneously adding the initiator potassium persulfate, sodium bisulfate, ferrous ammonium sulfate, desalted water and sulfur dioxide which are required by the reaction into the polymerization kettle together, controlling the polymerization temperature to 60 ℃, controlling the pH value of a polymerization reaction system to be 3.0, and carrying out aqueous phase precipitation polymerization reaction;

after the polymerization reaction, EDTA is added to terminate the reaction, the material obtained by the polymerization is filtered, washed and dried to obtain a dried polymer with the water content of 0.3%, the number average molecular weight of the obtained polymer is 3.2 ten thousand, the molecular weight distribution is 3.0, and the dried polymer is crushed into fine powder to obtain the polyacrylonitrile dry powder.

Example 1

The polyacrylonitrile resin and the dimethylacetamide at 80 ℃ are mixed at high speed in a Mark mixer, and the stock solution with the solid content of 28 weight percent is injected into a stock solution mixing tank. After mixing, maintaining the temperature of the mixture at 80 ℃ for dissolution, wherein the dissolution time is 8 hours, the stirring speed is 30 revolutions per minute, introducing inert gas in the dissolution process for emptying and deoxidizing, and after dissolution, the rotational viscosity of the spinning solution is 66000mpa.s, and the water content in the spinning solution is 0.2%.

Examples 2 to 6

A dope was prepared as in example 1, except that the stirring speed was 40 rpm, 50 rpm, 60 rpm, 70 rpm, 80 rpm in this order.

Examples 7 to 10

A dope was prepared as in example 3, except that the dissolution time was 6 hours, 7 hours, 9 hours, 10 hours.

Comparative example 1

A dope was prepared as in example 3, except that the dope mixing tank stirring assembly was a beveled blade non-serrated stirring paddle and stirring rod.

Comparative example 2

A dope was prepared as in example 3, except that the dope mixing tank stirring blade was a bevel blade zigzag stirring blade and a stirring rod, and there was no grinding plate.

Dry spinning was performed for examples 1 to 11 and comparative example 1, and the spinning process conditions were: the atmosphere of the channel is nitrogen, the upper temperature of the upper channel is 190 ℃, the lower temperature of the upper channel is 170 ℃, the residence time is 1.5s, and the channel draft is 4.5. Spraying, swinging and falling the channel formed tows to obtain nascent fibers, washing and drafting the nascent fibers at 75 ℃ for 30s, drafting the nascent fibers at a drafting rate of 4.5, and drying the nascent fibers at 120 ℃ for 10s to obtain the dry PAN long fibers.

Performance testing

The testing method comprises the following steps: in the production line, when the quality of the stock solution changes, yarn breakage occurs in the spinning process, acrylic fibers are broken, plates are required to be replaced, and the number of sleeves required to be replaced for producing 100 tons of acrylic fibers is used as a standard for evaluating the yarn breakage phenomenon or viscosity stability of the stock solution. The more broken filaments or the higher the viscosity, the more plate changes are required.

The pressure is the pressure at the nozzle of the spinning step in the spinning process, and when the nozzle pressure is too high, the powder is not sufficiently dissolved to block the nozzle in a solid form, so that the nozzle pressure is increased. The test results are shown in Table 1.

Table 1 test results

Of course, the foregoing is merely preferred embodiments of the present utility model and is not to be construed as limiting the scope of the embodiments of the present utility model. The present utility model is not limited to the above examples, and those skilled in the art will appreciate that the present utility model is capable of equally varying and improving within the spirit and scope of the present utility model.

Claims

1. An acrylonitrile-acrylic acid polymer dissolving apparatus characterized in that: the device comprises a stock solution mixing tank (1), wherein the stock solution mixing tank (1) comprises a shell (4) and a preparation cavity (13), and the shell (4) is provided with a stock solution inlet (2), a stock solution outlet (9) and a cylinder cover (14); a stirring assembly (3) is arranged in the stock solution mixing tank (1), the stirring assembly (3) comprises a stirring rod (12), and a stirring paddle (5) and a grinding plate (11) are connected to the stirring rod (12); the outer layer of the shell (4) is provided with a jacket (7), and the jacket (7) is provided with a jacket inlet (8), a jacket water outlet (6) and a jacket outlet (10); a thermometer (15) is arranged on the jacket water outlet (6).

2. The acrylonitrile-acrylic acid polymer dissolving apparatus according to claim 1, wherein: the stirring paddle (5) is fixedly connected with the stirring rod (12) through a bolt by adopting a hoop.

3. The acrylonitrile-acrylic acid polymer dissolving apparatus according to claim 1, wherein: the grinding plate (11) is anchor-type and is fixed with the stirring rod (12) through bolts by adopting hoops.

4. The acrylonitrile-acrylic acid polymer dissolving apparatus according to claim 1, wherein: the stirring paddle (5) is a down-pressing inclined blade paddle.

5. The acrylonitrile-acrylic acid polymer dissolving apparatus according to claim 1, wherein: the stirring rod (12) is connected with an upper group of stirring paddles (5), a middle group of stirring paddles and a lower group of stirring paddles which are arranged in a cross manner.

6. The acrylonitrile-acrylic acid polymer dissolving apparatus according to claim 1, wherein: the lower part and the side of the stirring paddle (5) are of a zigzag structure.

7. The acrylonitrile-acrylic acid polymer dissolving apparatus according to claim 1, wherein: the grinding plate (11) has an inverted saw tooth structure.

8. The acrylonitrile-acrylic acid polymer dissolving apparatus according to claim 7, wherein: the grinding plate (11) is overlapped with the stirring paddle (5), the gap between the grinding plate (11) and the stirring paddle is smaller than 1mm, and the grinding plate (11) is fixed with the inner wall of the stock solution mixing tank (1) and does not rotate along with the stirring rod (12).