A continuous bulk polymerization preparation system for superabsorbent resins

Abstract

The present invention provides a continuous bulk polymerization preparation system for superabsorbent resin, which is characterized by comprising: a preheating pipe array, a plurality of parallel and continuous preheating pipe arrays for preheating mixture A; a constant temperature heater, which is communicated with the preheating pipe array, and the preheated mixture A is temperature-controlled through the constant temperature heater; a static mixer, which is connected to the discharge port of the constant temperature heater, and an initiator addition port is arranged on one side of the static mixer; and a polymerization reactor. The present invention can not only greatly reduce the energy consumption intensity of industrial added value and complete the task of energy conservation and consumption reduction, but also meet the technical index requirements of superabsorbent resin at the same time.

Description

Technical Field

[0001] The present invention belongs to the field of preparation of superabsorbent resins, and relates to a preparation system for continuously polymerizing superabsorbent resins by bulk polymerization. Background Art

[0002] Currently, the main methods for preparing superabsorbent resins are aqueous solution polymerization process and inverse suspension polymerization process. A large amount of water needs to be introduced into the monomers before polymerization in both of these two processes, and then all the water is dried out after polymerization, resulting in a high energy consumption intensity of the industrial added value of superabsorbent resins. It is very necessary to innovate the production process, greatly reduce the energy consumption intensity of the industrial added value, and achieve the goal of energy conservation and consumption reduction.

[0003] In order to greatly reduce the energy consumption intensity of the industrial added value of superabsorbent resins and at the same time meet the technical index requirements of superabsorbent resins, the inventor of the present invention has conducted a large number of experiments and in-depth studies, and creatively invented a preparation system for continuously polymerizing superabsorbent resins by bulk polymerization.

[0004] To sum up, in order to solve the deficiencies in the prior art, the present invention designs a preparation system for continuously polymerizing superabsorbent resins by bulk polymerization, which can not only greatly reduce the energy consumption in the preparation process of superabsorbent resins, but also meet the technical index requirements of superabsorbent resins at the same time. Summary of the Invention

[0005] In order to solve the problems existing in the prior art, the present invention provides a preparation system for continuously polymerizing superabsorbent resins by bulk polymerization. The superabsorbent resin prepared by this preparation system can not only greatly reduce the energy consumption intensity of the industrial added value and complete the task of energy conservation and consumption reduction, but also meet the technical index requirements of superabsorbent resins at the same time.

[0006] The object of the present invention can be achieved by the following technical solutions:

[0007] A preparation system for continuously polymerizing superabsorbent resins by bulk polymerization, comprising:

[0008] Preheating pipes 2, a plurality of preheating pipes 2 arranged in parallel and continuously, and the preheating pipes 2 are used for preheating the mixture A;

[0009] Constant temperature heater 5, the constant temperature heater 5 is communicated with the preheating pipes 2, and the preheated mixture A is temperature-controlled by the constant temperature heater 5;

[0010] Static mixer 7, the static mixer 7 is connected to the outlet of the constant temperature heater 5, and an initiator addition port 6 is provided on one side of the static mixer 7;

[0011] The polymerization reactor 23 includes a reaction cavity, in which a spiral propeller 8 is provided, one end of the spiral propeller 8 is provided with a driving device, and a static mixer 7 is arranged at an end close to the driving device and is connected to the polymerization reactor 23; the pitch of the spiral propeller 8 gradually increases from the end close to the driving device to the end away from the driving device.

[0012] As a further improvement of the present scheme, the reaction cavity of the polymerization reactor 23 includes an initiation section 14, a heat exchange section 15, and a strong cooling section 16 which are arranged in sequence. The pitch of the initiation section 14 is a, the pitch of the heat exchange section 15 is b, and the pitch of the strong cooling section 16 is c, satisfying the quantitative relationship: a<b<c.

[0013] More specifically, the inner cavity diameter range of the polymerization reactor 23 is 305mm~865mm, and it includes an initiation section 14, a heat exchange section 15, and a strong cooling section 16 which are arranged in sequence. The length range of the initiation section 14 is 560mm~2500mm, the pitch a ranges from 52mm~75mm, the length range of the heat exchange section 15 is 600mm~2650mm, the pitch b ranges from 95mm~155mm, the length range of the strong cooling section 16 is 650mm~2750mm, and the pitch c ranges from 95mm~195mm. The values satisfy the quantitative relationship: a<b<c.

[0014] As a further improvement of the present scheme, the pitch ratio of the spirals of the initiating section 14 and the heat exchange section 15 of the polymerization reactor is 1:1.2 to 1:2.2, and the pitch ratio of the spirals of the initiating section 14 and the strong cooling section 16 of the polymerization reactor is 1:1.2 to 1:2.2.

[0015] As a further improvement of the present solution, the initiation section 14, the heat exchange section 15 and the strong cooling section 16 of the reaction cavity of the polymerization reactor 23 are separated by insulating gaskets.

[0016] More specifically, the three sections of the outer cylinder are connected by flanges, and insulating gaskets are installed between the flanges to prevent heat from running wildly between the three sections. The inner cavity of the polymerization reactor is connected, and there is a screw propeller in the middle. The material is transported from the inner cavity entrance to the outlet by the screw propeller.

[0017] As a further improvement of the present solution, a polymerization reactor outlet 11 is provided at the end of the polymerization reactor 23 , and a rotary cutter 12 is provided at the polymerization reactor outlet 11 , and the rotary cutter is used to pelletize or segment the polymer.

[0018] As a further improvement of the present solution, a strong heat exchange pipe unit 13 is further provided at the outlet 11 of the polymerization reactor.

[0019] More specifically, the strong cooling pipe unit 13 realizes the strong cooling function of the strong cooling section of the polymerization reactor. It is made of copper with good heat transfer performance and is structured as a matrix-shaped annular pipe. The low-temperature coolant flows inside the pipe to achieve the strong cooling function.

[0020] As a further improvement of this solution, the initiation section 14 is provided with an initiation section heating and temperature control device 10; an initiation section material temperature monitoring device 17 is also provided at the initiation section 14; a heat exchange section material temperature monitoring device 18 is provided in the heat exchange section; a polymerization reactor outlet material temperature monitoring device 19 is provided at the outlet of the polymerization reactor; a preheating pipe inlet temperature monitoring device 20 is provided at the inlet of the preheating pipe; a preheating pipe outlet temperature monitoring device 21 is provided at the outlet of the preheating pipe; a constant temperature heater outlet temperature monitoring device 22 is provided at the outlet of the constant temperature heater. The initiation section heating and temperature control device 10 has an electric heating component arranged on the cylinder wall. The above temperature monitoring is equivalent to temperature detection points, displaying temperature values, and meeting the temperature and temperature difference range requirements at various process conditions.

[0021] As a further improvement of this solution, it further includes a ripening device 24. The ripening device 24 is provided with a ripening device inlet 241 and a ripening device outlet 242. Inside the ripening device 24, there are a ripening device rotating disc 246 and an air-cooled net plate 244. Driven by the ripening device rotating disc 246, the air-cooled net plate 244 cools and conveys the polymer.

[0022] As a further improvement of this solution, the air-cooled net plate 244 is provided with through holes, and the through holes are round holes.

[0023] As a further improvement of this solution, the aperture of the round hole is 1.2 - 5.5 mm.

[0024] As a further improvement of this solution, the opening ratio of the air-cooled net plate 244 is 22% - 41%.

[0025] Compared with the prior art, the structural design of the present invention is reasonable and has the following beneficial effects:

[0026] 1) The preheating pipe plays two roles: aggregating heat release and preheating the mixture A. The polymerization heat is fully utilized. After coming out of the preheating pipe, the mixture A enters the constant-temperature heater for heating, then enters the static mixer to mix with the initiator, and finally enters the inner cavity of the polymerization reactor. The center of the inner cavity is a spiral propeller. The mixture A mixed with the initiator undergoes bulk polymerization reaction under the conditions of rapid stirring and heating temperature control. A strong heat exchanger is arranged at the rear section of the polymerization reactor to control the maximum temperature of the bulk polymerization reaction, prevent the maximum temperature from being too high, which may cause small polymer molecular weight, wide distribution, as well as polymer oxidation and yellowing caused by high temperature. After being extruded from the outlet of the polymerization reactor, the polymer is cut into pellets or segments by a rotary cutter, and then enters the curing device to continue the reaction and cooling, obtaining polymer B;

[0027] 2) The polymerization reactor consists of three sections, which are separated by adiabatic gaskets to reduce the heat leakage between the three metal inner cavities. The heat leakage between the three sections is not conducive to the temperature control and energy consumption loss of each section. The first section of the polymerization reactor is the initiation section, which has the function of heating and temperature control; the second section of the polymerization reactor is the heat exchange section, where part of the polymerization heat release causes the material to heat up itself and accelerate the polymerization, and the other part is transferred to the mixture A in the preheating pipe on the outer wall; the third section of the polymerization reactor is the strong heat exchange section, whose main function is to control the maximum temperature of the bulk polymerization reaction at 96°C to 135°C. The residence time of the material in the inner cavity of the polymerization reactor is 32 seconds to 150 seconds. The pitch ratio of the helices in the initiation section and the heat exchange section of the polymerization reactor is 1:1.2 to 1:2.2, and the pitch ratio of the helices in the initiation section and the strong cooling section of the polymerization reactor is 1:1.2 to 1:2.2. The polymerization reactor is designed into three sections to achieve the chain initiation of free radical polymerization in the present invention, that is, in the initial stage, heating is required to let the initiator initiate to form free radicals, the middle is the chain growth stage, and partial heat dissipation is used to control the rate and intensity of the polymerization reaction, and finally is the chain termination and chain transfer, and strong heat exchange and cooling are used to control the termination of the polymerization reaction. The pitches of the helices in the initiation section, heat exchange section, and strong cooling section of the polymerization reactor are different to control the residence time of the material in each section of the polymerization reactor. When the spiral propeller rotates at the same speed, a shorter pitch means a longer residence time of the material, and a longer pitch means a shorter residence time of the material. The pitch of the initiation section is short because the chain initiation of free radical polymerization is slow and requires a long time. The pitches of the heat exchange section and the strong cooling section are short because the chain growth and chain termination of free radical polymerization are fast;

[0028] 3) The ripening device is an air-cooled wire mesh chain circulation type. The residence time of the material in the ripening device is controlled to be 1 minute to 6 minutes, and the temperature control range of the material at the outlet of the ripening device is 70°C to 30°C, so as to achieve the two functions of complete polymerization reaction and cooling. The air-cooled wire mesh is arranged with round holes, the diameter of the round holes is 1.2 to 5.5 mm, and the opening ratio of the air-cooled wire mesh (the sum of the areas of all the openings on the wire mesh ÷ the total area of the wire mesh) is 22% to 41%. The size of the round hole diameter cannot allow the material to leak out from the round hole, and at the same time, it is necessary to ensure the penetration of cold air for cooling. The opening ratio of the air-cooled wire mesh balances the penetration of cold air and the structural mechanics of the air-cooled wire mesh. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a schematic structural diagram of the continuous bulk polymerization high-absorbency resin preparation system of the present invention.

[0030] Figure 2 is a schematic structural diagram of the ripening device of the present invention.

[0031] Figure 3 is a schematic structural diagram inside the ripening device of the present invention.

[0032] In the figure,

[0033] 1 - Inlet of preheating pipe, 2 - Preheating pipe, 3 - Outlet of preheating pipe, 4 - Heat insulation gasket, 5 - Constant temperature heater, 6 - Initiator addition, 7 - Static mixer, 8 - Spiral propeller, 9 - Motor, 10 - Temperature control of initiator section heating, 11 - Outlet of polymerization reactor, 12 - Rotary cutter, 13 - Strong cooling pipe unit, 14 - Initiator section, 15 - Heat exchange section, 16 - Strong cooling section, 17 - Temperature monitoring device for initiator section material, 18 - Temperature monitoring device for heat exchange section material, 19 - Temperature monitoring device for polymerization reactor outlet material, 20 - Temperature monitoring device for preheating pipe inlet, 21 - Temperature monitoring device for preheating pipe outlet, 22 - Temperature monitoring device for constant temperature heater outlet, 23 - Polymerization reactor;

[0034] 24 - Ripening device, 241 - Inlet of ripening device, 242 - Outlet of ripening device, 243 - Cooling air, 244 - Air-cooled wire mesh, 245 - Round holes on air-cooled wire mesh, 246 - Rotating disc of ripening device. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0035] The technical solution of the present invention will be further described below in conjunction with the embodiments and the drawings.

[0036] The product performance test methods for the examples and comparative examples are as follows:

[0037] (1) Centrifugal water retention rate

[0038] The Centrifuge Retention Capacity (abbreviated as "CRC") refers to the water absorption retention ratio of a unit mass of superabsorbent resin after free swelling in 0.9% sodium chloride brine for a certain period of time and then centrifuging to remove some water.

[0039] Specifically, it means weighing 0.2000 g of superabsorbent resin with a tea bag, immersing it in 0.9 wt% sodium chloride aqueous solution for 30 minutes to allow free swelling, and then the water absorption retention ratio (unit: g / g) after centrifuging to remove some water with a centrifuge (centrifugal force of 250 G). Centrifuge Retention Capacity = (m_after centrifugation - m_sample - m_blank) / m_sample.

[0040] (2) Absorption Under Pressure

[0041] The Absorption Under Pressure (abbreviated as "AUP") refers to the water absorption ratio of a unit mass of superabsorbent resin under the action of a certain pressure for a certain period of time. Specifically, it means the water absorption ratio (unit: g / g) after swelling 0.9000 g of water-absorbent resin in 0.9 wt% sodium chloride aqueous solution for 1 hour under a load of 0.7 psi. Absorption Under Pressure = (m_after water absorption - m_before water absorption) / m_sample.

[0042] The specific structure of a continuous bulk polymerization system for preparing superabsorbent resin of the present invention is as follows: including:

[0043] Preheating pipe array 2, a number of parallel and continuous preheating pipe arrays 2, which are used for preheating mixture A;

[0044] Constant temperature heater 5, the constant temperature heater 5 is connected to the preheating pipe array 2, and the preheated mixture A is temperature-controlled through the constant temperature heater 5;

[0045] Static mixer 7, the static mixer 7 is connected to the outlet of the constant temperature heater 5, and an initiator inlet 6 is provided on one side of the static mixer 7;

[0046] Polymerization reactor 23, the polymerization reactor 23 includes a reaction inner cavity, a spiral propeller 8 is provided in the reaction inner cavity, one end of the spiral propeller 8 is provided with a driving device, the static mixer 7 is arranged at one end close to the driving device and is connected to the polymerization reactor 23; the pitch of the spiral propeller 8 gradually increases from the end close to the driving device to the end far from the driving device.

[0047] Among them, the reaction inner cavity of the polymerization reactor 23 includes an initiation section 14, a heat exchange section 15, and a strong cooling section 16 arranged in sequence. The pitch of the initiation section 14 is a, the pitch of the heat exchange section 15 is b, and the pitch of the strong cooling section 16 is c, satisfying the quantitative relationship: a < b < c.

[0048] The pitch ratio of the helices of the initiation section 14 and the heat exchange section 15 of the polymerization reactor is 1:1.2 to 1:2.2, and the pitch ratio of the helices of the initiation section 14 and the strong cooling section 16 of the polymerization reactor is 1:1.2 to 1:2.2. The initiation section 14, the heat exchange section 15, and the strong cooling section 16 of the reaction inner cavity of the polymerization reactor 23 are separated by heat insulation gaskets. A polymerization reactor outlet 11 is provided at the end of the polymerization reactor 23, and a rotary cutter 12 is provided at the polymerization reactor outlet 11, and this rotary cutter is used to cut or segment the polymer.

[0049] A strong heat exchange tube unit 13 is also provided at the polymerization reactor outlet 11.

[0050] In the preparation system of the present invention, the specific settings in terms of temperature control are as follows: The initiation section 14 is provided with an initiation section heating temperature control 10; an initiation section material temperature monitoring device 17 is also provided at the initiation section 14; the heat exchange section is provided with a heat exchange section material temperature monitoring device 18; a polymerization reactor outlet material temperature monitoring device 19 is provided at the polymerization reactor outlet; a preheating tube inlet temperature monitoring device 20 is provided at the preheating tube inlet; a preheating tube outlet temperature monitoring device 21 is provided at the preheating tube outlet; a constant temperature heater outlet temperature monitoring device 22 is provided at the constant temperature heater outlet.

[0051] As Figure 2 shown, it further includes a ripening device 24. The ripening device 24 is provided with a ripening device inlet 241 and a ripening device outlet 242. The inside of the ripening device 24 is provided with a ripening device rotating disk 246 and an air-cooled net plate 244. Driven by the ripening device rotating disk 246, the air-cooled net plate 244 cools and conveys the polymer. Through holes are provided on the air-cooled net plate 244, and these through holes are round holes. The aperture of the round hole is 1.2 to 5.5 mm. The opening ratio of the air-cooled net plate 244 is 22% to 41%.

[0052] Using the above preparation system and the batching kettle, a high-absorbency resin is prepared by a continuous bulk polymerization method.

[0053] Example 1:

[0054] 300 kg of sodium acrylate and acrylic acid (sodium acrylate accounting for 75% of the molar fraction), 0.9 kg of difunctional crosslinking agent polyethylene glycol (600) diacrylate, 3 kg of dispersant fumed silica, and 0.04 kg of metal ion chelating agent disodium ethylenediaminetetraacetate are added to a batching kettle and stirred into mixture A in the batching kettle. The temperature of mixture A at that time is measured to be 22°C. Mixture A is pumped into a preheating pipe of a special polymerization reactor at a rate of 102 kg / h by a plunger pump. The temperature detection at the outlet of the preheating pipe shows that the temperature of mixture A is 43°C at this time. Mixture A enters a constant-temperature heater and is heated to 95°C, then enters a static mixer and is mixed with 0.32 kg / h of initiator sodium persulfate, and then enters the inner cavity of the polymerization reactor. The highest temperature in the inner cavity of the polymerization reactor is shown to be 123°C, and the residence time of the material in the inner cavity is 96 seconds. The material comes out from the outlet of the polymerization reactor, is pelletized by a rotary cutter, and then enters a curing device. After 2.1 minutes, polymer B at 52°C is obtained. Polymer B is crushed or ground, screened, and surface-treated to obtain the final product C.

[0055] Comparative Example 1

[0056] 300 kg of sodium acrylate and acrylic acid (sodium acrylate accounting for 75% of the molar fraction), 0.9 kg of difunctional crosslinking agent polyethylene glycol (600) diacrylate, 3 kg of dispersant fumed silica, and 0.04 kg of metal ion chelating agent disodium ethylenediaminetetraacetate are added to a batching kettle and stirred into a mixture in the batching kettle. The temperature of the mixture at that time is measured to be 22°C. Mixture A is pumped into a constant-temperature heater at a rate of 102 kg / h by a plunger pump and heated to 95°C, then enters a static mixer and is mixed with 0.32 kg / h of initiator sodium persulfate, and then enters a polymerization reactor composed of a one-stage equal-pitch screw propeller. The residence time is controlled to be 96 seconds. The highest temperature of the material in the polymerization reactor is measured to be 152°C. The material comes out from the outlet of the polymerization reactor, is pelletized by a rotary cutter (the particles are yellow because the material temperature in the polymerization reactor is relatively high, causing the inhibitor p-methoxyphenol introduced in acrylic acid to oxidize and turn yellow), and then enters a curing device. After 2.1 minutes, a yellow polymer at 102°C is obtained. The polymer is crushed or ground, screened, and surface-treated to obtain the final yellow product.

[0057] Comparative Example 2

[0058] Add 300 kg of sodium acrylate and acrylic acid (sodium acrylate accounts for 75% of the molar fraction), 301.2 kg of deionized water, and 0.9 kg of N,N-methylenebisacrylamide into the batching kettle. Start the stirring of the batching kettle, control the temperature to 82°C ± 2°C, and pump it into the static mixer at a rate of 215 kg / h. At the same time, add 20.8 kg of 1% aqueous solution of sodium persulfate, and carry out a polymerization reaction in the silica gel reactor of the circulating chain to obtain a polymer gel. The polymer gel is granulated, dried, crushed or ground, screened, and surface-treated to obtain the final product.

[0059] The superabsorbent resins obtained in Example 1, Comparative Example 1, and Comparative Example 2 are shown in Table 1 below:

[0060] Table 1 Performance test results of Example 1, Comparative Example 1, and Comparative Example 2

[0061]

[0062] It can be seen from the analysis of Table 1 that the preparation method of the continuous bulk polymerization superabsorbent resin provided by the present invention has obvious advantages of low energy consumption and less carbon dioxide emissions per ton of superabsorbent resin product, and the appearance color, centrifugal water retention rate, and pressure absorption rate indicators can be maintained quite well. It can not only greatly reduce the energy consumption in the preparation process of the superabsorbent resin, but also meet the technical index requirements of the superabsorbent resin at the same time.

[0063] What is described herein is only the preferred embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Modifications, supplements, or substitutions in a similar manner made by those skilled in the art to the specific embodiments described shall be covered within the protection scope of the present invention.

Claims

1. A continuous bulk polymerization high absorbent resin preparation system, characterized in that Comprising: Preheating pipes (2), a number of preheating pipes (2) arranged in parallel and continuously, and the preheating pipes (2) are used for preheating mixture A; Constant temperature heater (5), the constant temperature heater (5) is communicated with the preheating pipes (2), and the preheated mixture A is temperature-controlled through the constant temperature heater (5); Static mixer (7), the static mixer (7) is communicated with the discharge port of the constant temperature heater (5), and an initiator addition port (6) is arranged on one side of the static mixer (7); Polymerization reactor (23), the polymerization reactor (23) includes a reaction inner cavity, a spiral propeller (8) is arranged in the reaction inner cavity, a driving device is arranged at one end of the spiral propeller (8), and the static mixer (7) is arranged at one end close to the driving device and communicated with the polymerization reactor (23); the pitch of the spiral propeller (8) gradually increases from the end close to the driving device to the end far from the driving device.

2. The continuous bulk polymerization high absorbent resin preparation system according to claim 1, characterized in that The reaction inner cavity of the polymerization reactor (23) includes an initiation section (14), a heat exchange section (15), and a strong cooling section (16) arranged in sequence. The pitch of the initiation section (14) is a, the pitch of the heat exchange section (15) is b, and the pitch of the strong cooling section (16) is c, satisfying the quantitative relationship: a < b < c.

3. The continuous bulk polymerization high absorbent resin preparation system according to claim 2, characterized in that, The pitch ratio of the spirals of the initiation section (14) and the heat exchange section (15) of the polymerization reactor is 1:1.2 to 1:2.2, and the pitch ratio of the spirals of the initiation section (14) and the strong cooling section (16) of the polymerization reactor is 1:1.2 to 1:2.

2.

4. The continuous bulk polymerization high absorbent resin preparation system according to claim 3, characterized in that, The initiation section (14), the heat exchange section (15), and the strong cooling section (16) of the reaction inner cavity of the polymerization reactor (23) are separated by heat-insulating gaskets.

5. The continuous bulk polymerization high absorbent resin preparation system according to claim 3, characterized in that, A polymerization reactor outlet (11) is arranged at the end of the polymerization reactor (23), and a rotary cutter (12) is arranged at the polymerization reactor outlet (11), and the rotary cutter is used for pelletizing or segmenting the polymer.

6. The continuous bulk polymerization high absorbent resin preparation system according to claim 5, characterized in that, A strong cooling pipe unit (13) is also arranged at the polymerization reactor outlet (11).

7. The continuous bulk polymerization high absorbent resin preparation system according to claim 5, characterized in that, The initiation section (14) is provided with an initiation section heating temperature control (10); an initiation section material temperature monitoring device (17) is also arranged at the initiation section (14); a heat exchange section material temperature monitoring device (18) is arranged at the heat exchange section (15); a polymerization reactor outlet material temperature monitoring device (19) is arranged at the polymerization reactor outlet (11); a preheating pipe inlet temperature monitoring device (20) is arranged at the preheating pipe inlet; a preheating pipe outlet temperature monitoring device (21) is arranged at the preheating pipe outlet; a constant temperature heater outlet temperature monitoring device (22) is arranged at the constant temperature heater outlet.

8. The continuous bulk polymerization high absorbent resin preparation system according to claim 1, characterized in that It further includes a curing device (24), the curing device (24) is provided with a curing device inlet (241) and a curing device outlet (242), and a curing device rotating disk (246) and an air-cooling net plate (244) are arranged inside the curing device (24). Driven by the curing device rotating disk (246), the air-cooling net plate (244) cools and conveys the polymer.

9. The continuous bulk polymerization high absorbent resin preparation system according to claim 8, characterized in that, The air-cooling net plate (244) is provided with through holes, and the through holes are round holes.

10. The continuous bulk polymerization high absorbent resin preparation system according to claim 9, characterized in that, The aperture of the round hole is 1.2 to 5.5 mm.

11. The continuous bulk polymerization high absorbent resin preparation system according to claim 8 or 9, characterized in that, The porosity of the air-cooling net plate (244) is 22% to 41%.

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