PA6 polymerization reactor feed mechanism

Abstract

The utility model relates to PA6 production technical field, concretely for a kind of PA6 polymerization reactor feeding mechanism, including mixing tank and gear pump, fixedly connected with sample introduction tube on the gear pump, mixing mechanism is arranged between the sample introduction tube and mixing tank, for mixing sample to raw material and catalyst;The top of the mixing tank is provided with air pressure adjusting mechanism, for adjusting the pressure in mixing tank.The utility model can be assisted feeding by nitrogen through mixing tank, gear pump, sample introduction tube and mixing mechanism, avoid the existence material residue in pipeline, effectively enhance the stability of feeding, avoid the problem that material residue influences proportioning accuracy.Furthermore, the mixing mechanism can also premix raw material and additive, thereby greatly improve its mixing efficiency, reduce stirring length of time, while guaranteeing its full mixing.

Description

Technical Field

[0001] This utility model relates to the field of PA6 production technology, specifically to a PA6 polymerization reactor feeding mechanism. Background Technology

[0002] PA6 possesses excellent comprehensive properties, including good mechanical properties, good flexibility, wear resistance, oil resistance, and self-lubricating properties, and is widely used in the automotive industry, electronics and electrical appliance industry, machinery and equipment industry, construction industry, and other fields.

[0003] In the PA6 production process, caprolactam and additives are vertically fed through multiple pipelines using metering pumps. After mixing in a mixer, they are then transported to the reaction tank for reaction. However, because the raw materials and additives are added simultaneously according to the formula, the mixing effect is poor, the stirring and mixing time is long, and the possibility of side reactions increases. Furthermore, the existing material conveying system uses high-pressure propulsion from a gear pump and gravity assistance to remove residual material from the pipelines. Since caprolactam still has high viscosity in its liquid state, there is a possibility of residue sticking to the pipeline walls, affecting the accuracy of subsequent mixing and reaction. Therefore, we propose a new feeding mechanism for the PA6 polymerization reactor. Utility Model Content

[0004] The purpose of this invention is to provide a feeding mechanism for a PA6 polymerization reactor, which solves the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution: A PA6 polymerization reactor feeding mechanism includes a mixing tank and a gear pump. A sample inlet pipe is fixedly connected to the gear pump. A mixing mechanism is provided between the sample inlet pipe and the mixing tank for mixing and feeding raw materials and catalyst. A pressure regulating mechanism is provided at the top of the mixing tank for regulating the pressure inside the mixing tank.

[0006] Preferably, the mixing mechanism includes an air inlet pipe, which is fixedly installed at one end of the sample inlet tube near the gear pump. The sample inlet tube is a sleeve consisting of an inner tube and an outer tube, and the air inlet pipe and the inner tube are connected.

[0007] Preferably, the end of the injection tube away from the gear pump is detachably connected to a threaded tube via a connecting block. The threaded tube consists of an outer spiral tube and an inner spiral tube, and the outer spiral tube and the inner spiral tube are fixedly connected by a connecting plate.

[0008] Preferably, the inner tube of the injection tube is connected to the inner spiral tube, the outer tube of the injection tube is connected to the outer spiral tube, there are multiple spiral tubes, and adjacent spiral tubes are detachably connected by a connecting block, and the inner spiral tube passes through the surface of the mixing tank and is fixed to the mixing tank.

[0009] Preferably, multiple fan blades are fixedly installed on the inner wall of the connecting block, and the multiple fan blades are arranged in an array. The diameter of the inner spiral tube gradually decreases from one end near the sample inlet tube to the other end.

[0010] Preferably, the air pressure regulating mechanism includes a housing, which is fixedly installed on the top of the mixing tank. The housing has an air inlet and an air outlet, and the air inlet is connected to the mixing tank.

[0011] Preferably, a sealing ball is provided inside the housing, and a screw is rotatably connected through the top end of the housing. A pressure plate is threaded onto the surface of the screw, and the pressure plate and the sealing ball are connected by a spring.

[0012] Preferably, a pressure sensor is fixedly installed on the mixing tank, and a nitrogen pipe is fixedly installed on the mixing tank. The pressure sensor, the pressure regulating mechanism, and the nitrogen pipe are controlled by a PLC.

[0013] By employing the above technical solution, this utility model provides a feeding mechanism for a PA6 polymerization reactor that has at least the following beneficial effects: (1) This utility model, through a mixing tank, gear pump, injection pipe and mixing mechanism, can use nitrogen to assist in feeding, avoid material residue in the pipeline, effectively enhance the stability of feeding, and avoid the problem of material residue affecting the accuracy of the ratio. In addition, the mixing mechanism can also premix the raw materials and additives, thereby greatly improving the mixing efficiency, reducing the stirring time and ensuring that they are fully mixed.

[0014] (2) This utility model can avoid the influence of nitrogen-assisted feeding on the gas pressure in the mixing tank by using a mixing tank and a gas pressure regulating mechanism, so that the gas pressure in the mixing tank is always within the set range, and the gas pressure range can be adjusted to enhance adaptability and safety, and can effectively suppress the side reaction. Attached Figure Description

[0015] The accompanying drawings, which are included to provide a further understanding of the present invention, form part of this application: Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is a schematic diagram of the hybrid mechanism structure of this utility model; Figure 3 This is a schematic diagram of the spiral tube structure of this utility model. Figure 4 This is a schematic diagram of the connecting block structure of this utility model; Figure 5 This is a schematic diagram of the internal structure of the air pressure regulating mechanism of this utility model; Figure 6 This is a schematic diagram of the sample introduction structure of this utility model.

[0016] In the diagram: 1. Mixing vessel; 2. Gear pump; 3. Sample inlet tube; 4. Mixing mechanism; 5. Pressure regulating mechanism; 6. Pressure sensor; 41. Intake pipe; 42. Outer spiral tube; 43. Inner spiral tube; 44. Connecting block; 45. Fan blade; 51. Motor; 52. Housing; 53. Air inlet; 54. Air outlet; 55. Sealing ball; 56. Pressure plate; 57. Screw. Detailed Implementation

[0017] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0018] Please see Figures 1-6 A feeding mechanism for a PA6 polymerization reactor includes a mixing tank 1 and a gear pump 2. An inlet pipe 3 is fixedly connected to the gear pump 2. The inlet pipe 3 is a sleeve consisting of an inner pipe and an outer pipe, which are fixedly connected by a connecting plate. The inner pipe is used for the flow of raw materials and additives in the PA6 polymerization reaction. Hot water is circulated through the gap between the inner and outer pipes to maintain the temperature of caprolactam, the raw material for the PA6 polymerization reaction, and prevent its crystallization. The gear pump 2 can stably control the dosage of the transported raw materials and additives.

[0019] In addition, a mixing mechanism 4 is provided between the injection tube 3 and the mixing tank 1 for mixing and injecting the raw materials and catalyst, and for enhancing the fluidity of the liquid and the uniformity of mixing by aeration. A pressure regulating mechanism 5 is provided at the top of the mixing tank 1 to regulate the pressure inside the mixing tank 1, ensuring that the pressure inside the mixing tank 1 is within the range of uniform mixing and reaction inhibition.

[0020] Please see Figures 1-3The mixing mechanism 4 includes an inlet pipe 41, which is fixedly installed at the end of the sample inlet tube 3 near the gear pump 2 and is connected to the inner tube. The inlet pipe 41 can inject high-temperature nitrogen gas into the inner tube. The gas temperature is the same as the hot water temperature, ensuring that the nitrogen does not affect the flowability of caprolactam. The nitrogen gas has a certain pressure, which can increase the flow rate of caprolactam and additives, and can also drive the material flow after the gear pump 2 stops working, preventing residual material from remaining in the sample inlet tube 3.

[0021] Please see Figure 2 One end of the outer tube of the intake pipe 41 is detachably connected to an outer spiral tube 42 via a connecting block 44, and one end of the inner tube of the intake pipe 41 is detachably connected to an inner spiral tube 43 via a connecting block 44. Please refer to [link / reference]. Figure 3 The outer spiral tube 42 and the inner spiral tube 43 are fixedly connected by a connecting plate, ensuring a tight connection between them and unobstructed water flow in the gap between them. Hot water can be introduced through the gap between the outer spiral tube 42 and the inner spiral tube 43 to maintain temperature during mixing. The other end of the inner spiral tube 43 penetrates the surface of the mixing tank 1 and is fixedly connected to it. The diameter of the inner spiral tube 43 gradually decreases from one end near the inlet tube 3 to the other end. This gradual decrease in the inner diameter of the raw materials and additives as they move along the inner spiral tube 43 intensifies the collision between liquids, enhancing the mixing effect. Simultaneously, because the inner spiral tube 43 has a spiral structure, the turbulence of the liquid is enhanced as the raw materials and additives flow across the curved surface, further strengthening the mixing effect.

[0022] Please see Figure 3 Multiple fan blades 45 are fixedly installed on the inner wall of the connecting block 44, and the fan blades 45 are distributed in an array. The thickness of the fan blades 45 gradually increases from top to bottom in the direction of water flow. When the raw materials and additives pass through the fan blades 45, they will be disturbed, causing the liquid to turbulent, enhancing the fluidity between different liquids, thereby enhancing the uniformity of mixing between the raw materials and additives.

[0023] Please see Figures 4-6 The air pressure regulating mechanism 5 includes a housing 52, which is fixedly installed on the top of the mixing tank 1. The housing 52 has an air inlet 53 and an air outlet 54 for gas to enter and exit. The air inlet 53 is connected to the mixing tank 1. A sealing ball 55 is provided inside the housing 52. The sealing ball 55 can slide along the inside of the housing 52 and is in contact with both the air inlet 53 and the air outlet 54. Therefore, the position of the sealing ball 55 controls whether the air pressure regulating mechanism 5 is working.

[0024] It should be noted that a screw 57 is rotatably connected to the top of the housing 52, and a motor 51 is fixedly installed at the top of the screw 57. A pressure plate 56 is threaded onto the surface of the screw 57, and the pressure plate 56 is connected to the sealing ball 55 by a spring. When the motor 51 is working, it can drive the screw 57 to rotate. When the screw 57 rotates, it causes the pressure plate 56 to move, thereby adjusting the position of the pressure plate 56. This, in turn, adjusts the tension of the spring, thereby adjusting the elastic force of the spring on the sealing ball 55, and thus regulating the inlet air pressure of the air pressure regulating mechanism 5. In addition, the exhaust nitrogen can be recovered through a pipeline at the outlet 54.

[0025] Please see Figure 1 and Figure 6 The pressure sensor 6 is fixedly installed at the top of the mixing tank 1, and a nitrogen pipe is fixedly installed on the mixing tank 1. The pressure sensor 6, the pressure regulating mechanism 5, and the nitrogen pipe are controlled by a PLC. The pressure sensor 6 can monitor the gas pressure in the mixing tank 1 in real time, and the PLC controls the pressure range of the pressure regulating mechanism 5 and whether the nitrogen pipe is ventilated, thereby controlling the gas pressure in the mixing tank 1 within a certain range, and this range is adjustable.

[0026] Furthermore, the nitrogen pipe, in conjunction with the pressure regulating mechanism 5, can adjust the initial pressure range of the mixing tank 1 and can also expel the air inside the mixing tank 1 to maintain the nitrogen atmosphere inside the mixing tank 1 and prevent oxygen from participating in the formation of side reactions during mixing.

[0027] In addition, the air pressure inside the inner spiral tube 43 is greater than the air pressure inside the mixing tank 1, which allows the mixed material inside the inner spiral tube 43 to be quickly transported into the mixing tank 1 under pressure, reducing the transport time and thus reducing the residence time of the material in the pipeline, reducing the possibility of crystallization and adhesion.

[0028] A feeding mechanism for a PA6 polymerization reactor, the working principle of which is as follows: During operation, gear pump 2 is started to accurately measure and deliver the melted raw materials and additives into injection tube 3. Circulating hot water is circulated between the inner and outer tubes of injection tube 3 to keep the raw material caprolactam warm and prevent crystallization. Simultaneously, nitrogen gas is delivered into the inner tube through air inlet pipe 41 to transport the raw materials and additives.

[0029] Raw materials, additives, and nitrogen are introduced into the inner spiral tube 43 in a synchronized manner through different injection tubes 3. Under the accelerated delivery of nitrogen, the raw materials and additives are rapidly transported along the inner spiral tube 43. When the mixture passes through the inner wall arc surface and fan blade 45 of the inner spiral tube 43, the turbulence of the liquid is continuously enhanced, thereby enhancing the relative fluidity between different liquids and thus enhancing the uniformity of the mixing between the raw materials and additives.

[0030] The mixed material enters the mixing tank 1 through the outlet of the inner spiral tube 43. As the material and nitrogen are introduced into the mixing tank 1, the pressure inside increases. This increased pressure causes the gas to compress the sealing ball 55. When the pressure exceeds the spring force, the sealing ball 55 displaces, connecting the inlet 53 and outlet 54, allowing the gas inside the mixing tank 1 to be expelled and the pressure restored. The pressure sensor 6 monitors the pressure inside the mixing tank 1, and the PLC can accurately adjust the opening pressure of the pressure regulating mechanism 5 based on the pressure status within the mixing tank 1. This effectively enhances stability and safety.

[0031] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0032] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A feeding mechanism for a PA6 polymerization reactor, characterized in that: It includes a mixing tank (1) and a gear pump (2). A sample inlet tube (3) is fixedly connected to the gear pump (2). A mixing mechanism (4) is provided between the sample inlet tube (3) and the mixing tank (1) for mixing and injecting raw materials and catalyst. A pressure regulating mechanism (5) is provided at the top of the mixing tank (1) for regulating the pressure inside the mixing tank (1). The mixing mechanism (4) includes an air inlet pipe (41), which is fixedly installed at one end of the sample inlet pipe (3) near the gear pump (2). The sample inlet pipe (3) is a sleeve consisting of an inner tube and an outer tube. The air inlet pipe (41) is connected to the inner tube. The end of the injection tube (3) away from the gear pump (2) is detachably connected to a threaded tube via a connecting block (44). The threaded tube is composed of an outer spiral tube (42) and an inner spiral tube (43), and the outer spiral tube (42) and the inner spiral tube (43) are fixedly connected by a connecting plate.

2. The feeding mechanism for a PA6 polymerization reactor according to claim 1, characterized in that: The inner tube of the injection tube (3) is connected to the inner spiral tube (43), and the outer tube of the injection tube (3) is connected to the outer spiral tube (42). There are multiple spiral tubes, and adjacent spiral tubes are detachably connected by a connecting block (44). The inner spiral tube (43) passes through the surface of the mixing tank (1) and is fixed to the mixing tank (1).

3. The feeding mechanism for a PA6 polymerization reactor according to claim 1, characterized in that: Multiple fan blades (45) are fixedly installed on the inner wall of the connecting block (44), and the multiple fan blades (45) are arranged in an array. The diameter of the inner spiral tube (43) gradually decreases from one end near the sample inlet tube (3) to the other end.

4. The feeding mechanism for a PA6 polymerization reactor according to claim 1, characterized in that: The air pressure regulating mechanism (5) includes a housing (52), which is fixedly installed on the top of the mixing tank (1). The housing (52) has an air inlet (53) and an air outlet (54), and the air inlet (53) is connected to the mixing tank (1).

5. The PA6 polymerization reactor feeding mechanism according to claim 4, characterized in that: A sealing ball (55) is provided inside the housing (52), and a screw (57) is rotatably connected through the top of the housing (52). A pressure plate (56) is threaded onto the surface of the screw (57), and the pressure plate (56) and the sealing ball (55) are connected by a spring.

6. The feeding mechanism for a PA6 polymerization reactor according to claim 5, characterized in that: A pressure sensor (51) is fixedly installed on the mixing tank (1), and a nitrogen pipe is fixedly installed on the mixing tank (1). The pressure sensor (51), the pressure regulating mechanism (5), and the nitrogen pipe are controlled by a PLC.

Images