A reaction apparatus and system for preparing polyacrylamide

Abstract

The present application relates to the technical fields of high polymer preparation, in particular to a reaction device and system for preparing polyacrylamide, which provides a reaction device for preparing polyacrylamide, comprising a feeding port, a flow plate body and a discharging port; the two ends of the flow plate body are connected with the feeding port and the discharging port respectively, the flow plate body is inclined downward to make the prepolymer solution flow from the feeding port to the discharging port, and a plurality of heating devices are arranged at the bottom of the flow plate body, which are arranged along the flow direction of the material in the flow plate body to provide the flow plate body with increasing temperature from the feeding port to the discharging port. The present application provides a reaction device and system for preparing polyacrylamide, which can provide a temperature-controllable reaction device and system.

Description

Technical Field

[0001] This invention relates to the field of polymer preparation technology, and in particular to a reaction apparatus and system for preparing polyacrylamide. Background Technology

[0002] Polyacrylamide is a linear polymer compound. During polymerization, different monomers can be selected according to requirements to give the polymer multiple functions.

[0003] In related technologies, the preparation of polyacrylamide is an exothermic reaction, making it difficult to control the temperature inside the reactor. Both excessively high and low temperatures will reduce the reaction rate and degrade the product quality.

[0004] Therefore, in order to address the above shortcomings, there is an urgent need for a temperature-controllable reaction device and system. Summary of the Invention

[0005] This invention provides a reaction apparatus and system for preparing polyacrylamide, which can provide a temperature-controllable reaction apparatus and system.

[0006] In a first aspect, embodiments of the present invention provide a reaction apparatus for preparing polyacrylamide, comprising an inlet, a flow plate, and an outlet;

[0007] The two ends of the flow plate are connected to the inlet and the outlet, respectively. The flow plate is tilted downward so that the prepolymer solution flows from the inlet to the outlet. Multiple heating devices are provided at the bottom of the flow plate. The multiple heating devices are arranged along the flow direction of the material in the flow plate to provide the flow plate with an increasing temperature from the inlet to the outlet.

[0008] In one possible design, a conveying mechanism is also included, which includes a conveyor belt and baffles. The conveyor belt rotates cyclically, and the lower part of the conveyor belt is arranged parallel to the flow plate. The conveyor belt is provided with a plurality of the baffles. The rotation of the conveyor belt cyclically conveys the plurality of baffles to the surface of the flow plate.

[0009] When the baffle moves downward to the surface of the flow plate near the inlet, the two baffles and the flow plate form a box-shaped space containing the prepolymer solution. When the baffle moves to the surface of the flow plate near the outlet, the baffle moves upward along the conveyor belt to open the box-shaped space, and the product formed in the box-shaped space is transported to the outlet.

[0010] In one possible design, the flow plate is 55–60 m long and 0.8–1.2 m wide. The heating devices are spaced 1 m apart. The heating devices adjust their power to raise the temperature of the first half of the flow plate to 55–60 °C at a rate of 1.5–2.5 °C per meter, while the second half maintains a constant temperature of 55–60 °C. The first half is the half of the flow plate closest to the inlet, and the second half is the half of the flow plate closest to the outlet. The temperature of the prepolymer solution entering the flow plate is 2–7 °C.

[0011] In one possible design, temperature sensors are installed at 1m intervals on the flow plate. Each temperature sensor corresponds to and is electrically connected to the heating device. The temperature sensor transmits the detected temperature to the heating device, and the heating device adjusts its output power in real time according to the received temperature to control the temperature of the flow plate.

[0012] In one possible design, the height of the baffle is 5 to 8 cm.

[0013] In one possible design, the conveyor belt has a transmission speed of 60 m / h.

[0014] In one possible design, the discharge port is provided with a cutting component for cutting the generated colloid into blocks.

[0015] Secondly, embodiments of the present invention also provide a system for preparing polyacrylamide, based on a reaction apparatus according to any one of the above, the system comprising a mixing device, the reaction apparatus, and a processing device;

[0016] The mixing device is used to mix the various raw materials for preparing polyacrylamide uniformly to form the prepolymer solution;

[0017] The feed inlet of the reaction device is used to receive the prepolymer solution obtained by the mixing device, and the colloid obtained by the reaction device is transported to the processing device via the discharge outlet.

[0018] The processing device is used to granulate, dry, crush, sieve and package the colloid obtained from the reaction device in sequence.

[0019] In one possible design, the mixing device includes a batching tank, a feeding tank, an initiator batching tank, an initiator feeding tank, a polymerization mixing buffer tank, and a nitrogen tank;

[0020] The mixing tank is used to receive various raw materials for the polymerization reaction to complete the mixing process. The feed tank is used to receive the various ingredients from the mixing tank and mix them evenly. The initiator mixing tank is used to prepare initiators with different components. The initiator feed tank is used to mix the various initiator components from the initiator mixing tank. The polymerization mixing buffer tank is used to mix the materials from the feed tank and the initiator feed tank evenly and then introduce them into the feed inlet of the reaction device. The nitrogen tank is used to introduce nitrogen into the mixing tank, feed tank, initiator mixing tank, initiator feed tank, polymerization mixing buffer tank, and reaction device.

[0021] In one possible design, the processing apparatus includes a screw crusher, a first conveying auger, a granulator, a second conveying auger, a drying fluidized bed, a grinder, a cyclone dust collector, a fully enclosed vibrating screen, a blower, a finished product tank, a third conveying auger, and an automatic weighing and packaging machine.

[0022] The spiral crusher is used to receive the colloid output from the discharge port and crush it. The first conveying auger is used to convey the crushed colloid to the granulator for granulation. The second conveying auger is used to convey the granules prepared by the granulator to the fluidized bed dryer for drying. The grinder is used to grind and crush the granules dried by the fluidized bed dryer. The crushed granules are sent to the cyclone dust collector by the induced draft fan. The powder collected by the cyclone dust collector enters the fully enclosed vibrating screen for sieving. Powder with qualified particle size enters the finished product tank by the fan. Powder with unqualified particle size enters the grinder for further grinding. The finished powder in the finished product tank is transported to the weighing and packaging machine for dosage bagging by the third conveying auger.

[0023] Compared with the prior art, the present invention has at least the following beneficial effects:

[0024] In this embodiment, the flow plate serves as the site for the polymerization reaction of the prepolymer solution. The flow plate in this application is elongated and narrow. This design distributes the prepolymer solution within the flow plate, resulting in a lower liquid surface depth. A lower liquid surface facilitates heat dissipation, and the volume of prepolymer solution per unit length of the flow plate is smaller, leading to lower heat generation during the polymerization reaction. Therefore, the design of the flow plate is more conducive to controlling the reaction temperature of the polymerization reaction. Furthermore, by coordinating multiple heating devices, the temperature gradient of the entire prepolymer solution is increased, gradually controlling the reaction temperature within the optimal range, greatly improving the reaction rate and product quality. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of a system structure for preparing polyacrylamide provided in an embodiment of the present invention.

[0027] In the diagram: 1. Batching vessel; 2. Feeding vessel; 3. Initiator batching tank; 4. Initiator feeding tank; 5. Polymerization mixing buffer tank; 6. Nitrogen tank; 7. Reaction device; 71. Flow plate; 72. Conveyor belt; 73. Baffle; 8. Screw crusher; 9. First conveying auger; 10. Granulator; 11. Second conveying auger; 12. Drying fluidized bed; 13. Grinding mill; 14. Cyclone dust collector; 15. Fully enclosed vibrating screen; 16. Fan; 17. Finished product tank; 18. Third conveying auger; 19. Automatic weighing and packaging machine. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0029] In the description of the embodiments of the present invention, unless otherwise expressly specified and limited, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance; unless otherwise specified or stated, the term "multiple" refers to two or more; the terms "connected," "fixed," etc., should be interpreted broadly. For example, "connected" can be a fixed connection, a detachable connection, an integral connection, or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0030] like Figure 1 As shown, an embodiment of the present invention provides a reaction apparatus 7 for preparing polyacrylamide, including a feed inlet, a flow plate 71, and a discharge outlet;

[0031] The two ends of the flow plate 71 are connected to the inlet and the outlet respectively. The flow plate 71 is tilted downward so that the prepolymer solution flows from the inlet to the outlet. Multiple heating devices are provided at the bottom of the flow plate 71. The multiple heating devices are arranged along the flow direction of the material in the flow plate 71 to provide the flow plate 71 with an increasing temperature from the inlet to the outlet.

[0032] In this embodiment, the flow plate 71 serves as the site for the polymerization reaction of the prepolymer solution. The flow plate 71 of this application is elongated and narrow. This design distributes the prepolymer solution within the flow plate 71, resulting in a lower liquid surface depth. A lower liquid surface depth facilitates heat dissipation. Furthermore, the volume of prepolymer solution per unit length of the flow plate 71 is smaller, leading to lower heat generation during the polymerization reaction. Therefore, the design of the flow plate 71 is more conducive to controlling the reaction temperature of the polymerization reaction. Further, through the coordination of multiple heating devices, the temperature gradient of the entire prepolymer solution is increased, gradually controlling the reaction temperature within the optimal range, greatly improving the reaction rate and product quality.

[0033] It should be noted that gradient heating can prevent the temperature of the prepolymer solution from rising too quickly due to an overly vigorous polymerization reaction, which would ultimately hinder the proper control of the reaction temperature.

[0034] In some embodiments of the present invention, a conveying mechanism is also included, which includes a conveyor belt 72 and baffles 73. The conveyor belt 72 rotates cyclically, and the lower part of the conveyor belt 72 is arranged parallel to the flow plate 71. The conveyor belt 72 is provided with a plurality of baffles 73. The rotation of the conveyor belt 72 cyclically conveys the plurality of baffles 73 to the surface of the flow plate 71.

[0035] When the baffle 73 moves downward to the surface of the flow plate 71 near the inlet, the two baffles 73 and the flow plate 71 form a box-shaped space containing the prepolymer solution. When the baffle 73 moves to the surface of the flow plate 71 near the outlet, the baffle 73 moves upward along the conveyor belt 72 to open the box-shaped space, and the product formed in the box-shaped space is transported to the outlet.

[0036] In this embodiment, when the baffle 73 moves onto the flow channel, it forms a box-shaped space. As the baffle 73 moves, the prepolymer solution within the box-shaped space also moves with it. The moving speed of the baffle 73 is the moving speed of the prepolymer solution, and the liquid surface does not fluctuate significantly during this movement. By controlling the moving speed of the baffle 73 and the power of the heating device, the temperature of the prepolymer solution at different locations can be precisely controlled, allowing the prepolymer solution to gradually heat up to the optimal reaction temperature. Furthermore, the baffle 73 effectively isolates the prepolymer solution in different box-shaped spaces, thereby effectively preventing heat transfer between the prepolymer solutions in different box-shaped spaces, which is more conducive to achieving precise temperature control.

[0037] In some embodiments of the present invention, the flow plate 71 is 55-60m long and 0.8-1.2m wide, and the heating devices are arranged at 1m intervals. The heating devices adjust their power to raise the temperature of the first half of the flow plate 71 to 55-60°C at a heating rate of 1.5-2.5°C per meter, while the second half maintains a constant temperature of 55-60°C. The first half is the half of the flow plate 71 closest to the inlet, and the second half is the half of the flow plate 71 closest to the outlet. The temperature of the prepolymer solution entering the flow plate 71 is 2-7°C.

[0038] In this embodiment, the flow plate 71 is 55–60 m long and 0.8–1.2 m wide, allowing a large amount of prepolymer solution to be arranged at a relatively low depth within it. Heating devices are spaced 1 m apart; this arrangement allows for flexible and precise control of temperature changes along the length of the flow plate 71 by adjusting the power of the heating devices. The first half of the heating channel is temperature-controlled by the heating devices, raising the temperature to 55–60°C at a rate of 1.5–2.5°C per meter, thus gradually and controllably raising the prepolymer solution to the optimal reaction temperature. The second half maintains the prepolymer solution temperature at the optimal reaction temperature by controlling the power of the heating devices.

[0039] It should be noted that, compared to water bath temperature control, this application achieves more precise temperature control through the combination of a narrow, elongated flow plate 71 and a heating device. Water bath temperature control, due to its circular internal reaction chamber where all prepolymer solutions react, results in a large amount of heat generated that cannot be dissipated quickly via heat transfer, especially the heat generated in the center. Therefore, even with water bath temperature control, the reaction temperature varies in different parts of the chamber, leading to reduced reaction efficiency and inconsistent product quality.

[0040] In some embodiments of the present invention, a temperature sensor is provided at 1m intervals on the flow plate 71. The temperature sensor corresponds to and is electrically connected to the heating device. The temperature sensor transmits the temperature it detects to the heating device. The heating device adjusts its output power in real time according to the temperature it receives to control the temperature of the flow plate 71.

[0041] In this embodiment, the temperature collected by the temperature sensor in real time is fed back to its corresponding heating device in real time. The heating device adjusts its power in real time according to the received temperature so that the temperature of the flowing plate 71 is always maintained at the preset temperature.

[0042] In some embodiments of the present invention, the height of the baffle 73 is 5 to 8 cm.

[0043] In this embodiment, the height of the baffle 73 limits the height of the prepolymer solution surface. Therefore, the height of the baffle 73 can be designed according to the preset liquid level.

[0044] In some embodiments of the present invention, the transmission speed of the conveyor belt 72 is 60 m / h.

[0045] In this embodiment, the transmission speed of the conveyor belt affects the reaction time of the prepolymer solution in the flow plate 71. The faster the conveyor belt 72 travels, the shorter the reaction time of the prepolymer solution; conversely, the slower the conveyor belt 72 travels, the longer the reaction time of the prepolymer solution. For the polymerization reaction to prepare polyacrylamide, the speed of the conveyor belt 72 is controlled at 60 m / h, ensuring that the prepolymer solution is fully reacted when it flows to the outlet, resulting in a high preparation rate and complete reaction of the reactants.

[0046] In some embodiments of the present invention, the discharge port is provided with a cutting component, which is used to cut the generated colloid into blocks.

[0047] This invention also provides a system for preparing polyacrylamide, based on the reaction apparatus 7 of any one of the above, the system including a mixing device, a reaction apparatus 7 and a processing device;

[0048] The mixing device is used to mix the various raw materials for preparing polyacrylamide uniformly to form a prepolymer solution;

[0049] The feed inlet of the reaction device 7 is used to receive the prepolymer solution obtained by the mixing device, and the colloid obtained by the reaction device 7 is transported to the processing device through the discharge outlet.

[0050] The processing device is used to granulate, dry, crush, sieve and package the colloid obtained from the reaction device 7 in sequence.

[0051] In some embodiments of the present invention, the mixing device includes a batching tank 1, a feeding tank 2, an initiator batching tank 3, an initiator feeding tank 4, a polymerization mixing buffer tank 5, and a nitrogen tank 6;

[0052] The mixing tank 1 is used to receive the various raw materials for the polymerization reaction to complete the mixing. The feeding tank 2 is used to receive the various ingredients from the mixing tank 1 and mix them evenly. The initiator mixing tank 3 is used to prepare initiators with different components. The initiator feeding tank 4 is used to mix the various initiator components from the initiator mixing tank 3. The polymerization mixing buffer tank 5 is used to mix the materials from the feeding tank 2 and the initiator feeding tank 4 evenly and then introduce them into the feed port of the reaction device 7. The nitrogen tank 6 is used to introduce nitrogen into the mixing tank 1, the feeding tank 2, the initiator mixing tank 3, the initiator feeding tank 4, the polymerization mixing buffer tank 5, and the reaction device 7.

[0053] In some embodiments of the present invention, the processing apparatus includes a spiral crusher 8, a first conveying auger 9, a granulator 10, a second conveying auger 11, a drying fluidized bed 12, a grinder 13, a cyclone dust collector 14, a fully enclosed vibrating screen 15, a blower 16, a finished product tank 17, a third conveying auger 18, and an automatic weighing and packaging machine 19.

[0054] The spiral crusher 8 is used to receive the colloid output from the discharge port and crush it. The first conveying auger 9 is used to convey the crushed colloid to the granulator 10 for granulation. The second conveying auger 11 is used to convey the granules prepared by the granulator 10 to the drying fluidized bed 12 for drying. The grinder 13 is used to grind and crush the granules dried by the drying fluidized bed 12. The crushed granules are sent to the cyclone dust collector 14 by the blower 16. The powder collected by the cyclone dust collector 14 enters the fully enclosed vibrating screen 15 for sieving. The powder with qualified particle size enters the finished product tank 17 by the blower 16. The powder with unqualified particle size enters the grinder 13 for further grinding. The finished powder in the finished product tank 17 is transported to the automatic weighing and packaging machine 19 for dosage and bagging by the third conveying auger 18.

[0055] To more clearly illustrate the technical solution and advantages of the present invention, the lifting system will be described in detail below through embodiments.

[0056] Example 1

[0057] (1) Ingredients

[0058] The temperature of the mixing tank 1 is controlled at 2°C using a circulating refrigerant. 45% acrylamide, 80% DMC (methacryloyloxyethyltrimethylammonium chloride), and demineralized water are sequentially metered and pumped into the mixing tank 1 at a mass ratio of 10:2:1, controlling the acrylamide monomer concentration at 34.6%. Nitrogen gas is introduced into the mixing tank 1 through the outlet valve of nitrogen tank 6 to remove oxygen from the liquid raw materials. The agitator in the mixing tank 1 is turned on and stirred for 1 hour. Ten minutes before the end of stirring, a complexing agent dissolved in the demineralized water is added at a concentration of 100 ppm. The preferred complexing agent is diethyltriaminepentaacetic acid or ethylenediaminetetraacetic acid.

[0059] The temperature of the initiator mixing tank 3 is controlled at 2°C by circulating refrigerant. One part of demineralized water is added to the initiator mixing tank 3, ultrasonic stirring is turned on, and nitrogen deoxygenation is turned on. Then, the redox initiator composed of potassium persulfate and sodium bisulfite (the amount of initiator added is 0.35% of the monomer mass, and the mass ratio of sodium bisulfite to potassium persulfate in the initiator system is 1:5) is added to the initiator mixing tank 3.

[0060] (2) Feed polymerization

[0061] Before the batching process is completed, nitrogen is introduced from nitrogen tank 6 into feed kettle 2, initiator feed kettle 4, and polymerization mixing buffer tank 5 to remove oxygen. The temperature of feed kettle 2 and initiator feed kettle 4 is controlled at about 2°C by circulating refrigerant. Nitrogen is introduced from nitrogen tank 6 into reaction device 7 to maintain a slight positive pressure of 0.10 MPa. The gradient temperature control system of reaction device 7 is started to prepare for polymerization feeding.

[0062] After the ingredients meet the requirements, the reaction solution is pumped from the mixing tank 1 into the feeding tank 2, and the stirring of the feeding tank 2 is started; the initiator is pumped from the initiator mixing tank 3 into the initiator feeding tank 4, and the ultrasonic stirring of the initiator feeding tank 4 is started.

[0063] Simultaneously, the feed pumps of feed vessel 2 and initiator feed tank 4 are started. The two feed streams converge at the hydraulic spiral nozzle in the polymerization mixing buffer tank 5 according to the set ratio flow rate. The reaction liquid phase flow velocity of feed vessel 2 is high, which drives the spiral propeller at the nozzle to rotate and perform preliminary mixing with the initiator. Under the action of ultrasonic stirring at the bottom of polymerization mixing buffer tank 5, the mixture is further mixed. The fully mixed reaction material enters the reaction device 7 at the set flow rate.

[0064] The reaction device 7 has a plate width of 1 meter and an effective length of 60 meters. Temperature control is achieved through digital electric heating and variable frequency pump circulating hot water. Within 1 meter of the feed in reaction device 7, the temperature is heated to approximately 10°C, maintaining a liquid level of 5 cm and a material flow rate of 60 m / h. The temperature control system gradually increases the temperature to 55°C in increments of 1.8°C per meter for the first 25 meters, maintaining relative stability at each gradient terminal to achieve a final reaction temperature of 60°C. Acrylamide and DMC polymerize to form cationic polyacrylamide gel. The polymerization reaction time is 1 hour, with a conversion rate of 100%. The cationic polyacrylamide gel is cut into blocks by a scraper and cutter at the discharge end of the reaction plate and falls into the storage silo.

[0065] After the storage bin of the reaction device 7 is full, the lower electric mechanism opens the unloading bin door of the storage bin, and the material is extruded by the screw crusher 8 and sent to the granulator 10 for granulation via the first conveying auger 9.

[0066] (3) Granulation and drying

[0067] The cationic polyacrylamide gel blocks are extruded into granules by granulator 10, and then conveyed to vibrating fluidized bed drying 12 via second conveying auger 11 for drying. The drying temperature is controlled at 140℃, and the drying time is 1.1 hours. The blown-out material is recovered by cyclone separator and bag filter dust collector, and then sent to grinder 13 for grinding. The steam is drawn out by induced draft fan and discharged after drying. After drying, the moisture content of the cationic polyacrylamide is less than 10%.

[0068] (4) Crushing, sieving, and packaging

[0069] The dried material enters the grinder 13 for crushing. After crushing, it is sent to the cyclone dust collector 14 by an induced draft fan. The collected material enters the fully enclosed vibrating screen 15 for sieving. No waste gas is generated during the sieving process. The particle size is customized according to customer requirements. Material with unqualified particle size is returned to the grinder 13 for repeated crushing and sieving until the particle size is qualified. Then, it is sent to the finished product tank 17 by the blower 16 for storage. When sold, it is sent to the automatic weighing and packaging machine 19 for weighing and bagging via the third conveying auger 18.

[0070] Example 2

[0071] (1) Ingredients

[0072] The temperature of the mixing tank 1 is controlled at 2°C using circulating refrigerant. 45% acrylamide, 80% DMC (methacryloyloxyethyltrimethylammonium chloride), and demineralized water are sequentially metered and pumped into the mixing tank 1 at a mass ratio of 10:2:1, controlling the acrylamide monomer concentration at 34.6%. Nitrogen gas is introduced into the mixing tank 1 through the outlet valve of nitrogen tank 6 to remove oxygen from the liquid raw materials. The agitator in the mixing tank 1 is turned on and stirred for 45 minutes. Ten minutes before the end of stirring, a complexing agent dissolved in the demineralized water is added at a concentration of 100 ppm. The preferred complexing agent is diethyltriaminepentaacetic acid or ethylenediaminetetraacetic acid.

[0073] The temperature of the initiator mixing tank 3 is controlled at 2°C by circulating refrigerant. One part of demineralized water is added to the initiator mixing tank 3, ultrasonic stirring is turned on, and nitrogen deoxygenation is turned on. Then, the redox initiator composed of potassium persulfate and sodium bisulfite (the amount of initiator added is 0.30% of the monomer mass, and the mass ratio of sodium bisulfite to potassium persulfate in the initiator system is 1:4.5) is added to the initiator mixing tank 3.

[0074] (2) Feed polymerization

[0075] Before the batching process is completed, nitrogen is introduced from nitrogen tank 6 into feed kettle 2, initiator feed kettle 4, and polymerization mixing buffer tank 5 to remove oxygen. The temperature of feed kettle 2 and initiator feed kettle 4 is controlled at about 2°C by circulating refrigerant. Nitrogen is introduced from nitrogen tank 6 into reaction device 7 to maintain a slight positive pressure of 0.10 MPa. The gradient temperature control system of reaction device 7 is started to prepare for polymerization feeding.

[0076] After the ingredients meet the requirements, the reaction solution is pumped from the mixing tank 1 into the feeding tank 2, and the stirring of the feeding tank 2 is started; the initiator is pumped from the initiator mixing tank 3 into the initiator feeding tank 4, and the ultrasonic stirring of the initiator feeding tank 4 is started.

[0077] Simultaneously, the feed pumps of feed vessel 2 and initiator feed tank 4 are started. The two feed streams converge at the hydraulic spiral nozzle in the polymerization mixing buffer tank 5 according to the set ratio flow rate. The reaction liquid phase flow velocity of feed vessel 2 is high, which drives the spiral propeller at the nozzle to rotate and perform preliminary mixing with the initiator. Under the action of ultrasonic stirring at the bottom of polymerization mixing buffer tank 5, the mixture is further mixed. The fully mixed reaction material enters the reaction device 7 at the set flow rate.

[0078] The reaction device 7 has a plate width of 1 meter and an effective length of 60 meters. Temperature control is achieved through digital electric heating and variable frequency pump circulating hot water. Within 1 meter of the feed in reaction device 7, the temperature is heated to approximately 10°C, maintaining a liquid level of 5 cm. The material flow rate is controlled at 60 m / h. The temperature control system gradually increases the temperature to 55°C in increments of 1.8°C per meter for the first 25 meters, maintaining relative stability at each gradient terminal to achieve a final reaction temperature of 58°C. Acrylamide and DMC polymerize to form cationic polyacrylamide gel. The polymerization reaction time is 1 hour, with a conversion rate of 100%. The cationic polyacrylamide gel is cut into blocks by a scraper and cutter at the discharge end of the reaction plate and falls into the storage silo.

[0079] After the storage bin of the reaction device 7 is full, the lower electric mechanism opens the unloading bin door of the storage bin, and the material is extruded by the screw crusher 8 and sent to the granulator 10 for granulation via the first conveying auger 9.

[0080] (3) Granulation and drying

[0081] The cationic polyacrylamide gel blocks are extruded into granules by granulator 10, and then conveyed to vibrating fluidized bed drying 12 via second conveying auger 11 for drying. The drying temperature is controlled at 130℃, and the drying time is 1.1 hours. The blown-out material is recovered by cyclone separator and bag filter dust collector, and then sent to grinder 13 for grinding. The steam is drawn out by induced draft fan and discharged after drying. After drying, the moisture content of the cationic polyacrylamide is less than 10%.

[0082] (4) Crushing, sieving, and packaging

[0083] The dried material enters the grinder 13 for crushing. After crushing, it is sent to the cyclone dust collector 14 by an induced draft fan. The collected material enters the fully enclosed vibrating screen 15 for sieving. No waste gas is generated during the sieving process. The particle size is customized according to customer requirements. Material with unqualified particle size is returned to the grinder 13 for repeated crushing and sieving until the particle size is qualified. Then, it is sent to the finished product tank 17 by the blower 16 for storage. When sold, it is sent to the automatic weighing and packaging machine 19 for weighing and bagging via the third conveying auger 18.

[0084] Example 3

[0085] (1) Ingredients

[0086] The temperature of the mixing tank 1 is controlled at 2°C using circulating refrigerant. 45% acrylamide, 80% DMC (methacryloyloxyethyltrimethylammonium chloride), and demineralized water are sequentially metered and pumped into the mixing tank 1 at a mass ratio of 10:2:1, controlling the acrylamide monomer concentration at 34.6%. Nitrogen gas is introduced into the mixing tank 1 through the outlet valve of nitrogen tank 6 to remove oxygen from the liquid raw materials. The agitator in the mixing tank 1 is turned on and stirred for 45 minutes. Ten minutes before the end of stirring, a complexing agent dissolved in the demineralized water is added at a concentration of 100 ppm. The preferred complexing agent is diethyltriaminepentaacetic acid or ethylenediaminetetraacetic acid.

[0087] The temperature of the initiator mixing tank 3 is controlled at 2℃ by circulating refrigerant. One part of demineralized water is added to the initiator mixing tank 3, ultrasonic stirring is turned on, and nitrogen deoxygenation is turned on. Then, the redox initiator composed of potassium persulfate and sodium bisulfite (the amount of initiator added is 0.25% of the monomer mass, and the mass ratio of sodium bisulfite to potassium persulfate in the initiator system is 1:4.0) is added to the initiator mixing tank 3.

[0088] (2) Feed polymerization

[0089] Before the batching process is completed, nitrogen is introduced from nitrogen tank 6 into feed kettle 2, initiator feed kettle 4, and polymerization mixing buffer tank 5 to remove oxygen. The temperature of feed kettle 2 and initiator feed kettle 4 is controlled at about 2°C by circulating refrigerant. Nitrogen is introduced from nitrogen tank 6 into reaction device 7 to maintain a slight positive pressure of 0.10 MPa. The gradient temperature control system of reaction device 7 is started to prepare for polymerization feeding.

[0090] After the ingredients meet the requirements, the reaction solution is pumped from the mixing tank 1 into the feeding tank 2, and the stirring of the feeding tank 2 is started; the initiator is pumped from the initiator mixing tank 3 into the initiator feeding tank 4, and the ultrasonic stirring of the initiator feeding tank 4 is started.

[0091] Simultaneously, the feed pumps of feed vessel 2 and initiator feed tank 4 are started. The two feed streams converge at the hydraulic spiral nozzle in the polymerization mixing buffer tank 5 according to the set ratio flow rate. The reaction liquid phase flow velocity of feed vessel 2 is high, which drives the spiral propeller at the nozzle to rotate and perform preliminary mixing with the initiator. Under the action of ultrasonic stirring at the bottom of polymerization mixing buffer tank 5, the mixture is further mixed. The fully mixed reaction material enters the reaction device 7 at the set flow rate.

[0092] The reaction device 7 has a plate width of 1 meter and an effective length of 60 meters. Temperature control is achieved through digital electric heating and variable frequency pump circulating hot water. Within 1 meter of the feed in reaction device 7, the temperature is heated to approximately 10°C, maintaining a liquid level of 5 cm and a material flow rate of 60 m / h. The temperature control system gradually increases the temperature to 55°C in increments of 1.8°C per meter for the first 25 meters, maintaining relative stability at each gradient terminal to achieve a final reaction temperature of 55°C. Acrylamide and DMC polymerize to form cationic polyacrylamide gel. The polymerization reaction time is 1 hour, with a conversion rate of 100%. The cationic polyacrylamide gel is cut into blocks by a scraper and cutter at the discharge end of the reaction plate and falls into the storage silo.

[0093] After the storage bin of the reaction device 7 is full, the lower electric mechanism opens the unloading bin door of the storage bin, and the material is extruded by the screw crusher 8 and sent to the granulator 10 for granulation via the first conveying auger 9.

[0094] (3) Granulation and drying

[0095] The cationic polyacrylamide gel blocks are extruded into granules by granulator 10, and then conveyed to vibrating fluidized bed drying 12 via second conveying auger 11 for drying. The drying temperature is controlled at 130℃, and the drying time is 1.1 hours. The blown-out material is recovered by cyclone separator and bag filter dust collector, and then sent to grinder 13 for grinding. The steam is drawn out by induced draft fan and discharged after drying. After drying, the moisture content of the cationic polyacrylamide is less than 10%.

[0096] (4) Crushing, sieving, and packaging

[0097] The dried material enters the grinder 13 for crushing. After crushing, it is sent to the cyclone dust collector 14 by an induced draft fan. The collected material enters the fully enclosed vibrating screen 15 for sieving. No waste gas is generated during the sieving process. The particle size is customized according to customer requirements. Material with unqualified particle size is returned to the grinder 13 for repeated crushing and sieving until the particle size is qualified. Then, it is sent to the finished product tank 17 by the blower 16 for storage. When sold, it is sent to the automatic weighing and packaging machine 19 for weighing and bagging via the third conveying auger 18.

[0098]

[0099]

[0100] Comparison of product indicators through examples shows that: under the conditions of consistent reactant concentration and the same stirring speed, the stirring time can be shortened by 15 minutes from the usual 1 hour; in terms of product molecular weight, the added initiator dosage of 0.30% at a ratio of approximately 1:4.5 is higher than that of 0.35%, while less than 0.3% results in a lower molecular weight, thus reducing the initiator dosage by more than 14% compared to the current process; in terms of the final reaction temperature, it can be controlled at around 60℃, which is more than 33% lower than the 95℃ of the existing process, effectively suppressing the occurrence of side reactions and reducing the content of metal ions; especially in the drying process, the drying time of the same power equipment and process is shortened from 2 hours to between 1.2 and 1.5 hours, with a very significant effect; in terms of reaction time, it is reduced from about 5 hours for batch reaction to about 1 hour, with a very significant effect; from the observation of the reaction process, when there is more initiator, the reaction rate is relatively faster, and the reactant color is uneven, with clumps and linear areas.

[0101] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A reaction apparatus for preparing polyacrylamide, characterized in that, Includes the inlet, the flow plate, and the outlet; The two ends of the flow plate are connected to the inlet and the outlet respectively. The flow plate is tilted downward so that the prepolymer solution flows from the inlet to the outlet. Multiple heating devices are provided at the bottom of the flow plate. The multiple heating devices are arranged along the flow direction of the material in the flow plate to provide the flow plate with an increasing temperature from the inlet to the outlet. It also includes a conveying mechanism, which includes a conveyor belt and baffles. The conveyor belt rotates in a cycle. The lower part of the conveyor belt is arranged parallel to the flow plate. The conveyor belt is provided with multiple baffles. The rotation of the conveyor belt circulates and conveys multiple baffles to the surface of the flow plate. When the baffle moves downward to the surface of the flow plate near the inlet, the two baffles and the flow plate form a box-shaped space containing the prepolymer solution. When the baffle moves to the surface of the flow plate near the outlet, the baffle moves upward along the conveyor belt to open the box-shaped space, and the product formed in the box-shaped space is transported to the outlet. The flow plate is 55-60m long and 0.8-1.2m wide. The heating devices are spaced 1m apart. The heating devices adjust their power to raise the temperature of the first half of the flow plate to 55-60℃ at a rate of 1.5-2.5℃ per meter, while the second half maintains a constant temperature of 55-60℃. The first half is the half of the flow plate closest to the inlet, and the second half is the half of the flow plate closest to the outlet. The temperature of the prepolymer solution when it enters the flow plate is 2-7℃. Temperature sensors are installed at 1m intervals on the flowing plate. Each temperature sensor corresponds to and is electrically connected to the heating device. The temperature sensor transmits the detected temperature to the heating device. The heating device adjusts its output power in real time according to the received temperature to control the temperature of the flowing plate. The height of the baffle is 5-8cm; The conveyor belt has a transmission speed of 60 m / h.

2. The reaction apparatus according to claim 1, characterized in that, The discharge port is equipped with a cutting component, which is used to cut the generated colloid into blocks.

3. A system for preparing polyacrylamide, characterized in that, The system based on the reaction apparatus according to any one of claims 1-2 includes a mixing device, the reaction apparatus, and a processing device; The mixing device is used to mix the various raw materials for preparing polyacrylamide uniformly to form the prepolymer solution; The feed inlet of the reaction device is used to receive the prepolymer solution obtained by the mixing device, and the colloid obtained by the reaction device is transported to the processing device via the discharge outlet. The processing device is used to granulate, dry, crush, sieve and package the colloid obtained from the reaction device in sequence.

4. The system according to claim 3, characterized in that, The mixing device includes a batching tank, a feeding tank, an initiator batching tank, an initiator feeding tank, a polymerization mixing buffer tank, and a nitrogen tank; The mixing tank is used to receive various raw materials for the polymerization reaction to complete the mixing process. The feed tank is used to receive the various ingredients from the mixing tank and mix them evenly. The initiator mixing tank is used to prepare initiators with different components. The initiator feed tank is used to mix the various initiator components from the initiator mixing tank. The polymerization mixing buffer tank is used to mix the materials from the feed tank and the initiator feed tank evenly and then introduce them into the feed inlet of the reaction device. The nitrogen tank is used to introduce nitrogen into the mixing tank, feed tank, initiator mixing tank, initiator feed tank, polymerization mixing buffer tank, and reaction device.

5. The system according to claim 3, characterized in that, The processing equipment includes a spiral crusher, a first conveying auger, a granulator, a second conveying auger, a drying fluidized bed, a grinder, a cyclone dust collector, a fully enclosed vibrating screen, a blower, a finished product tank, a third conveying auger, and an automatic weighing and packaging machine; The spiral crusher is used to receive the colloid output from the discharge port and crush it. The first conveying auger is used to convey the crushed colloid to the granulator for granulation. The second conveying auger is used to convey the granules prepared by the granulator to the fluidized bed dryer for drying. The grinder is used to grind and crush the granules dried by the fluidized bed dryer. The crushed granules are sent to the cyclone dust collector by the induced draft fan. The powder collected by the cyclone dust collector enters the fully enclosed vibrating screen for sieving. Powder with qualified particle size enters the finished product tank by the fan. Powder with unqualified particle size enters the grinder for further grinding. The finished powder in the finished product tank is transported to the automatic weighing and packaging machine for dosage bagging by the third conveying auger.

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