Discharging and strip casting device of nylon 66 polymerization kettle

Abstract

The utility model belongs to the technical field of chemical equipment, and particularly relates to a nylon 66 polymerizer discharging and strip casting device. Comprising a casting head, a heat conduction jacket is arranged outside the casting head, a melt runner is arranged in the casting head, and the casting head further comprises a purging pipeline communicated to the interior of the melt runner; a strip casting unit is arranged at the bottom of the strip casting head and comprises a strip casting plate and a distribution disc attached to the feeding side of the strip casting plate in a sealed mode, a distribution hole is formed in the distribution disc, the upper end of the distribution hole communicates with the lower end of the melt runner, the lower end of the distribution hole communicates with a strip casting hole of the strip casting plate, and a replaceable discharging head is embedded in the strip casting hole. The discharging heads have different sizes and specifications; and the electric heating rod is embedded in the cavity wall of the die body between the distribution disc and the casting strip plate. The device can effectively achieve heat preservation and blockage prevention, meanwhile, the replaceable discharging head is adopted to adapt to materials with different viscosities so as to guarantee uniform pelletizing, in addition, a high-pressure steam blowing pipeline is arranged to prevent material residues, and therefore stable and continuous production is achieved.

Description

Technical Field

[0001] This utility model belongs to the field of chemical equipment technology, specifically relating to a nylon 66 polymerization reactor discharge casting device. Background Technology

[0002] Nylon 66, a high-performance engineering plastic, has a production process that mainly includes salt formation, concentration, polymerization, discharge, pelletizing, drying, and screening. The discharge process is a critical batch operation after polymerization. Specifically, the molten material is extruded into strips by a casting device at 280-285℃ and 0.5-0.8MPa nitrogen pressure, then rapidly cooled by water spray before being pelletized into granules, and finally entering the drying process. However, existing casting devices have many defects, seriously affecting product quality and production efficiency. Firstly, there is the problem of black particle entrainment. After each discharge, the high-viscosity molten material remaining in the device, under continuous heating in the heat-conducting jacket without precise temperature control, remains in a state of overheating and carbonizes to form black particles. These black particles are carried out with the next batch of material, leading to a decrease in product purity. To mitigate this impact, the initial discharge material needs to be discharged into a waste hopper, resulting in raw material waste, reduced product yield, and subsequent manual removal of the black particles, incurring significant labor costs. Secondly, the discharge speed is poorly adaptable. The existing equipment uses a fixed-size discharge hole, which cannot adjust the discharge speed according to the viscosity deviation of different grades of nylon 66. When the material viscosity fluctuates, it is easy to cause the material strip to shake, resulting in large deviations in pellet size and poor uniformity. In addition, there are problems with casting strip blockage and irregularly shaped particles. After pelleting, the residual material that has cooled and solidified is prone to blockage of the casting strip, resulting in abnormal discharge of the next batch and producing a large number of irregularly shaped particles such as skewed particles, agglomerated particles, and long particles. These irregularly shaped particles are separated into substandard materials in the subsequent vibrating screening, further reducing the product yield. Utility Model Content

[0003] To address the shortcomings of the existing technology, the present invention aims to provide a nylon 66 polymerization reactor discharge casting device. This device utilizes electric heating rods on both sides of the casting strip plate for continuous heat preservation, effectively preventing solidification and blockage of the melt within the casting strip holes. It employs detachable and replaceable discharge heads, and by configuring discharge heads with different orifice sizes, it adapts to the discharge speed requirements of materials with varying viscosities, thereby ensuring uniform pellet size and reducing the generation of irregularly shaped particles. Simultaneously, a high-pressure steam purging pipeline is installed inside the device, allowing for thorough purging of the internal flow channels and cavity walls after each pelletizing process. This prevents viscous material residue, adhesion, and high-temperature carbonization and blackening, achieving stable and clean continuous production.

[0004] This utility model is achieved using the following technical solution:

[0005] The nylon 66 polymerization reactor discharge casting device includes a casting head, an external heat-conducting jacket, and a melt flow channel inside the casting head. It also includes a purging pipeline that penetrates the casting head body and connects to the melt flow channel. The upper end of the melt flow channel is connected to a melt valve at the top of the casting head. A casting unit is located at the bottom of the casting head. The casting unit includes a casting plate and a distribution plate sealed to the feed side of the casting plate. The distribution plate has a distribution hole, the upper end of which connects to the lower end of the melt flow channel, and the lower end of which connects to the casting hole of the casting plate. A replaceable discharge head with different sizes is nested inside the casting hole. The device also includes an electric heating rod embedded in the mold cavity wall between the distribution plate and the casting plate, arranged along the full forming width direction of the casting head.

[0006] The feed end of the melt valve is connected to the discharge port of the polymerization reactor.

[0007] The heat-conducting jacket is provided with a heat-conducting oil inlet and a heat-conducting oil outlet, which are arranged diagonally.

[0008] The melt flow channel is provided with a temperature detection interface on its side wall, and a thermometer extends into the melt flow channel through the interface.

[0009] The edge of the cast strip plate is provided with fixing holes, and the distribution plate is provided with mounting holes coaxial with the fixing holes of the cast strip plate at the corresponding positions.

[0010] The number of electric heating rods is two or more.

[0011] The discharge head has a funnel-shaped structure, including a rectangular feed section at the top, a trapezoidal transition section in the middle, and a flat slit discharge section at the bottom.

[0012] The melt flow channel has a symmetrical cavity structure, with a frustum-shaped feed section at the top, a concave arc transition section in the middle, and a guide section that converges to both sides at the bottom. The inner walls of each section are smooth curved surfaces. The lower end of the guide section is connected to the edge of the distribution hole, and the width of the guide section matches the total width of the distribution hole.

[0013] The purging medium introduced into the purging pipeline is high-pressure steam.

[0014] The working principle of the nylon 66 polymerization reactor discharge casting device is as follows:

[0015] After polymerization in the polymerization reactor, molten nylon 66 material (280-285℃) is introduced into the melt valve at the top of the casting head under a nitrogen pressure of 0.5-0.8MPa. It then flows into a symmetrical cavity-structured melt channel within the casting head. This melt channel features a frustum-shaped feed section at the top, a concave arc transition section in the middle, and a guide section that converges to both sides at the bottom. The smooth curved surface design of the inner wall guides the melt to flow evenly towards the distribution plate. A heat-conducting jacket is installed on the outside of the melt channel of the casting head. Heat-conducting oil circulates through diagonally arranged inlets and outlets, precisely controlling the temperature of the melt channel. Simultaneously, thermometers on the sidewalls of the melt channel monitor the internal temperature in real time, ensuring the material remains in a stable molten state.

[0016] Molten material flows out from the guide section of the melt flow channel and precisely connects with the distribution holes of the distribution plate. After being evenly distributed through the distribution holes, it enters the casting holes of the casting strip plate. During this process, electric heating rods embedded in the mold cavity wall between the distribution plate and the casting strip plate are arranged along the full forming width of the casting strip head, which can accurately compensate for the temperature at the periphery, eliminate temperature attenuation at the edges, and prevent the melt from crystallizing and sticking to the mold at the edges. The material is extruded into a strip shape through the funnel-shaped discharge head nested in the casting strip hole, completing the casting strip forming.

[0017] After a batch of material is discharged, high-pressure steam is introduced into the melt channel through the purging pipeline to purge and clean the melt channel, distribution hole and discharge head, thoroughly removing residual material and preventing solidification blockage and the formation of carbonized black particles. When it is necessary to produce different grades of Nylon 66, the discharge head in the casting strip hole can be directly replaced (select the corresponding size specification) to adapt to the discharge speed requirements of materials with different viscosities, ensuring the stability of the strip and the uniformity of pellet cutting.

[0018] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0019] (1) The nylon 66 polymerization reactor discharge casting device of this utility model sets a heat-conducting jacket on the outside of the melt flow channel at the casting head and uses a thermometer to achieve accurate monitoring and temperature control, avoiding the overheating and carbonization of residual materials. At the same time, high-pressure steam is introduced through the purging pipeline to thoroughly clean the melt flow channel between batches, reducing black particle entrainment from the source. There is no need to discharge waste at the beginning of discharge, which significantly improves product yield and finished product purity and reduces the cost of manual particle picking.

[0020] (2) The nylon 66 polymerization reactor discharge casting device of the present invention has a replaceable funnel-shaped discharge head of different sizes nested in the casting strip hole. It can be flexibly replaced according to the viscosity deviation of different grades of nylon 66, accurately match the discharge speed, avoid material strip shaking, and effectively improve the uniformity of pellet size.

[0021] (3) The nylon 66 polymerization reactor discharge casting device described in this utility model is equipped with a purging pipeline, which can promptly remove residual solidified material in the casting strip plate and distribution plate flow channel after each discharge, avoid blockage of the casting strip plate, thereby reducing the generation of irregular particles such as skewed particles and fused particles, and greatly improving the product yield.

[0022] (4) The nylon 66 polymerization reactor discharge casting device described in this utility model forms a dual temperature control system through the heat-conducting jacket and the electric heating rods on both sides of the casting strip plate. This system ensures the stability of the melt flow channel temperature and can accurately replenish the temperature of the casting strip plate, ensuring that the temperature of the molten material is uniform during the molding process and further improving the stability of the casting strip and pellets. Attached Figure Description

[0023] Figure 1 This is a front view of the nylon 66 polymerization reactor discharge casting device of this utility model;

[0024] Figure 2 This utility model Figure 1 AA section view;

[0025] Figure 3 This is a bottom view of the nylon 66 polymerization reactor discharge casting device described in this utility model;

[0026] Figure 4 This is a schematic diagram of the distribution disk described in this utility model;

[0027] In the diagram: 1. Cast strip head; 2. Heat-conducting jacket; 3. Melt flow channel; 4. Purge pipeline; 5. Melt valve; 6. Cast strip plate; 7. Distribution plate; 8. Distribution hole; 9. Discharge head; 10. Electric heating rod; 11. Heat transfer oil inlet; 12. Heat transfer oil outlet; 13. Thermometer; 14. Fixing hole; 15. Mounting hole. Detailed Implementation

[0028] To make the objectives and technical solutions of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings.

[0029] Example 1

[0030] like Figure 1-4As shown, the nylon 66 polymerization reactor discharge casting device includes a casting head 1, a heat-conducting jacket 2 on the outside of the casting head 1, a melt flow channel 3 inside the casting head 1, and a purging line 4 that penetrates the casting head 1 body and connects to the inside of the melt flow channel 3. The upper end of the melt flow channel 3 is connected to a melt valve 5 at the top of the casting head 1. The bottom of the casting head 1 is provided with a casting unit, which includes a casting plate 6 and a distribution plate 7 that is sealed and fitted to the feed side of the casting plate 6. The distribution plate 7 is provided with a distribution hole 8, the upper end of which is connected to the lower end of the melt flow channel 3, and the lower end of which is connected to the casting hole of the casting plate 6. A replaceable discharge head 9 is nested inside the casting hole, and the discharge head 9 has different sizes and specifications. It also includes an electric heating rod 10, which is embedded in the mold cavity wall between the distribution plate 7 and the casting plate 6 and arranged along the full forming width direction of the casting head 1.

[0031] The feed end of the melt valve 5 is connected to the discharge port of the polymerization reactor.

[0032] The heat-conducting jacket 2 is provided with a heat-conducting oil inlet 11 and a heat-conducting oil outlet 12, which are arranged diagonally.

[0033] The melt flow channel 3 is provided with a temperature detection interface on its side wall, and the thermometer 13 extends into the melt flow channel 3 through the interface.

[0034] The edge of the cast strip plate 6 is provided with fixing holes 14, and the distribution plate 7 is provided with mounting holes 15 coaxial with the fixing holes 14 of the cast strip plate 6 at the corresponding position.

[0035] The number of electric heating rods 10 is four.

[0036] The discharge head 9 has a funnel-shaped structure, including a rectangular feeding section at the top, a trapezoidal transition section in the middle, and a flat slit discharge section at the bottom.

[0037] The melt flow channel 3 is a symmetrical cavity structure, with a frustum-shaped feed section at the top, an inwardly concave arc transition section in the middle, and a guide section that converges to both sides at the bottom. The inner walls of each section are smooth curved surfaces. The lower end of the guide section is connected to the edge of the distribution hole 8, and the width of the guide section matches the total width of the distribution hole 8.

[0038] The purging medium introduced into the purging pipeline 4 is high-pressure steam.

[0039] The specific steps for doing this are as follows:

[0040] After polymerization in the polymerization reactor, the molten nylon 66 material is kept at a temperature of 280°C. Under the pressure of nitrogen gas at 0.5 MPa, it first enters the melt valve 5 at the top of the casting head 1 through the feed end of the melt valve 5, and then flows smoothly into the symmetrical cavity structure melt channel 3 inside the casting head 1 through the melt valve 5. The upper part of the melt channel is a frustum-shaped feed section, the middle part is an inwardly concave arc transition section, and the lower part is a guide section that converges to both sides. The smooth curved surface of the inner wall can guide the melt to flow downward evenly.

[0041] The melt flow channel 3 of the casting head 1 is provided with a heat-conducting jacket 2. The heat-conducting oil enters from the heat-conducting oil inlet 11 on the heat-conducting jacket 2 and flows out through the diagonally arranged heat-conducting oil outlets 12, forming a circulation channel to precisely control the temperature of the melt flow channel 3. The thermometer 13 installed at the temperature detection interface on the side wall of the melt flow channel 3 monitors the temperature of the material in the cavity in real time, ensuring that the molten material is always in a stable molten state and avoiding abnormal temperature that could cause changes in material viscosity and affect molding.

[0042] The molten material flows out from the guide section of the melt flow channel 3 and precisely connects with the distribution hole 8 of the distribution plate 7. After being uniformly distributed through the distribution hole 8, it continuously enters the casting hole on the casting strip plate 6. During this process, the electric heating rod 10 embedded in the mold cavity wall between the distribution plate 7 and the casting strip plate 6 works continuously along the full forming width direction of the casting strip head 1 to precisely replenish the temperature of the periphery, effectively eliminate the temperature decay at the edge, prevent the molten material in the casting strip hole from solidifying due to the temperature drop, and avoid the problem of blockage in the casting strip hole.

[0043] Under pressure, the material passes through the funnel-shaped discharge head 9 nested inside the casting strip hole and is squeezed into a continuous strip shape, completing the casting strip forming operation. After a batch of nylon 66 material is discharged and cast, the purging pipeline 4 is opened to introduce high-pressure steam into the melt flow channel 3. The high-pressure steam flows through the melt flow channel 3, the distribution hole 8 and the discharge head 9 in sequence, thoroughly purging and cleaning each flow channel and forming structure, completely removing residual molten material in the cavity and flow channel, avoiding the residual material from cooling and solidifying and causing blockage of the device, and preventing the residual material from carbonizing and forming black particles under the continuous heating of the heat-conducting jacket 2.

[0044] When it is necessary to produce different grades of Nylon 66 products, the discharge head 9 in the casting strip hole is directly replaced according to the viscosity deviation requirements of different grades of materials. The funnel-shaped discharge head 9 of the corresponding size and specifications is selected to adapt to the discharge speed of molten materials with different viscosities, ensuring the stability of the strip during the casting process, thereby ensuring the uniformity of particle size in the subsequent pelletizing operation and meeting the production process requirements of different grades of Nylon 66.

Claims

1. A nylon 66 polymerizer discharge cast banding apparatus characterized by, The device includes a casting head (1), a heat-conducting jacket (2) on the outside of the casting head (1), a melt flow channel (3) inside the casting head (1), and a purging line (4) that penetrates the body of the casting head (1) and connects to the inside of the melt flow channel (3). The upper end of the melt flow channel (3) is connected to the melt valve (5) at the top of the casting head (1). The bottom of the casting head (1) is provided with a casting unit, which includes a casting plate (6) and a sealing element that is fitted to the casting plate (6). The feed side has a distribution plate (7), which has a distribution hole (8). The upper end of the distribution hole (8) is connected to the lower end of the melt flow channel (3), and the lower end of the distribution hole (8) is connected to the casting strip hole of the casting strip plate (6). A replaceable discharge head (9) is nested in the casting strip hole. The discharge head (9) has different sizes and specifications. It also includes an electric heating rod (10), which is embedded in the mold cavity wall between the distribution plate (7) and the casting strip plate (6).

2. The nylon 66 polymerization kettle take-off cast banding apparatus of claim 1, wherein, The feed end of the melt valve (5) is connected to the discharge port of the polymerization reactor.

3. The nylon 66 polymerization kettle take-off cast banding apparatus of claim 1, wherein, The heat-conducting jacket (2) is provided with a heat-conducting oil inlet (11) and a heat-conducting oil outlet (12), and the heat-conducting oil inlet (11) and the heat-conducting oil outlet (12) are arranged diagonally.

4. The nylon 66 polymerization kettle take-off cast strip apparatus of claim 1 wherein, A temperature detection interface is provided on the side wall of the melt flow channel (3), and a thermometer (13) extends into the melt flow channel (3) through the interface.

5. The nylon 66 polymerization kettle take-off cast strip apparatus of claim 1 wherein, The edge of the cast strip plate (6) is provided with fixing holes (14), and the distribution plate (7) is provided with mounting holes (15) coaxial with the fixing holes (14) of the cast strip plate (6) at the corresponding position.

6. The nylon 66 polymerization kettle take-off cast strip apparatus of claim 1 wherein, The number of electric heating rods (10) is two or more.

7. The nylon 66 polymerization kettle take-off cast strip apparatus of claim 1 wherein, The discharge head (9) has a funnel-shaped structure, including a rectangular feeding section at the top, a trapezoidal transition section in the middle, and a flat slit discharge section at the bottom.

8. The nylon 66 polymerization kettle take-off cast strip apparatus of claim 1 wherein, The melt flow channel (3) is a symmetrical cavity structure. Its upper part is a frustum-shaped feed section, the middle part is an inwardly concave arc transition section, and the lower part is a guide section that converges to both sides. The inner wall of each section is a smooth curved surface. The lower end of the guide section is connected to the edge of the distribution hole (8), and the width of the guide section matches the total width of the distribution hole (8).

9. The nylon 66 polymerization kettle take-off cast strip apparatus of claim 1 wherein, The purging medium introduced into the purging pipeline (4) is high-pressure steam.

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