Underwater granulator

Abstract

The utility model discloses an underwater granulator, which is used for making a molten polymer into polymer particles, and comprises a forming and conveying assembly, a forming and conveying assembly, a forming and conveying assembly, a forming and conveying assembly and a forming and conveying assembly, and the forming and conveying assembly comprises an extruding and pressurizing module, and the extruding and pressurizing module is used for pressurizing and plasticizing the molten polymer into a linear solution; the cutting assembly comprises a water tank and a cutter module arranged in the water tank, constant-temperature water flow flowing in the fixed direction is arranged in the water tank, the linear solution flows into the cutter module in the water tank after being extruded by the extrusion pressurization module, the linear solution is cut into polymer particles through the cutter module, and the polymer particles flow along with the constant-temperature water flow; the conveying assembly comprises a feeding pipeline and a material distributing pipe, an opening is formed in the bottom of the feeding pipeline, the material distributing pipe is communicated with the opening, a material distributing shifting piece is arranged at the opening, when the material distributing shifting piece is opened, the polymer particles flow into the material distributing pipe from the feeding pipeline, and when the material distributing shifting piece is closed, the polymer particles flow into the next working procedure from the feeding pipeline. The material outlets can be quickly and conveniently converted, material waste is avoided, the whole process is easy to operate, and the labor intensity of workers is reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to mechanical equipment field, especially a kind of underwater pelletizer. BACKGROUND

[0002] TPV material particles are a kind of high-performance thermoplastic elastomer material, which is composed of rubber phase and plastic phase by dynamic vulcanization process. Rubber phase is usually selected from, such as ethylene-propylene-diene rubber (EPDM), nitrile rubber (NBR), etc., which gives the material good elasticity, flexibility and other rubber properties; The plastic phase is generally polypropylene (PP), polyethylene (PE) and other polyolefin plastics, which provides thermoplastic processing performance and certain rigidity and strength. The two phases form a special cross-linking structure during vulcanization, making TPV have the advantages of both rubber and plastic.

[0003] When the material needs to be replaced in the production process, or the production is abnormal (the color changes or the unqualified material is caused by not adding), the produced material needs to be isolated in time to avoid the unqualified material entering the next process, causing the whole warehouse finished product to be unqualified. The existing isolation method needs to be manually connected from the branch pipe below to the outside for sub-packaging into bags, which is very inconvenient to operate, and the material is easy to scatter on the ground, causing material waste and difficult to clean. UTILITY MODEL CONTENT

[0004] The utility model discloses a kind of underwater pelletizers, material outlet can be quickly and conveniently converted, avoid the waste of material, and the whole process is simple to operate, reduce the labor intensity of worker.

[0005] To solve the above technical problems, the embodiment of the utility model discloses a kind of underwater pelletizers for making polymer particles from molten polymer, comprising:

[0006] The forming conveying assembly includes an extrusion pressurizing module for extruding the molten polymer into a linear solution after pressurizing and plasticizing the molten polymer;

[0007] The cutting assembly includes a water tank and a cutter module arranged in the water tank, and a constant-temperature water flow flowing in a fixed direction is arranged in the water tank. The linear solution flows into the cutter module in the water tank after being extruded by the extrusion pressurizing module. The linear solution is cut into polymer particles by the cutter module and flows with the constant-temperature water flow.

[0008] The conveying assembly comprises a feeding pipe and a distribution pipe, the bottom of the feeding pipe is provided with an opening, the distribution pipe is communicated with the opening, and a distribution switch is arranged at the opening, polymer particles flow into the distribution pipe from the feeding pipe when the distribution switch is opened, and the polymer particles flow into the next process from the feeding pipe when the distribution switch is closed.

[0009] The technical scheme can quickly and conveniently switch the material outlet, avoids waste of the material, and has simple operation and reduced labor intensity of workers.

[0010] According to another specific embodiment of the utility model, the utility model discloses an extrusion pressurization module, which comprises:

[0011] The polymer melt flows into the double-screw extruder from the previous process, and the double-screw extruder uniformly mixes the molten polymer after heating the polymer melt to a molten state;

[0012] The melt pump is used for pressurizing the molten polymer;

[0013] The screen changer is used for filtering the molten polymer pressurized by the melt pump;

[0014] The die head extrudes the molten polymer pressurized by the melt pump, the die head is provided with a die orifice, a plurality of through holes for extruding the molten polymer are arranged in an array at the cross section of the die orifice, and the molten polymer is extruded to form a linear solution through the through holes.

[0015] According to another specific embodiment of the utility model, the utility model discloses an extrusion pressurization module, which comprises:

[0016] The water pump comprises a radial nozzle and a tangential nozzle, the radial nozzle is arranged towards the cutter module and is used for flushing the cutter module to prevent polymer particles from adhering, and the tangential nozzle is used for pushing water in the water tank to flow in a preset direction to send the polymer particles to the feeding pipe to flow into the next process in the preset direction;

[0017] The heat exchanger is used for keeping the water in the water tank at a constant temperature within a preset temperature threshold.

[0018] According to another specific embodiment of the utility model, the utility model discloses an extrusion pressurization module, which comprises:

[0019] The cutter unit comprises a cutter, the cutter is connected with the driving motor through a shaft coupling, and the cutter is rotated by the driving motor to cut the linear solution into polymer particles; and the radial nozzle is arranged towards the cutter;

[0020] The fixed knife unit comprises a fixed knife, which is fixedly installed on the opposite side of the movable knife and forms a shearing gap with the movable knife, and is used for completely cutting the linear solution.

[0021] According to another specific embodiment of the utility model, the utility model discloses an embodiment of the utility model discloses a cutter module further comprises:

[0022] The adjusting mechanism comprises a cutter shaft and an adjusting component connected with the cutter shaft, the movable knife is installed on the cutter shaft, and the adjusting component can push the cutter shaft to move along the extension direction of the cutter shaft to adjust the gap between the movable knife and the fixed knife.

[0023] The pressure sensor is arranged on the movable knife and is used for detecting the contact pressure when each blade on the movable knife cuts.

[0024] According to another specific embodiment of the utility model, the utility model discloses an embodiment of the utility model discloses that the recognition unit is arranged above the opening, and the recognition unit is used for identifying the color of the polymer particles on the feeding pipeline.

[0025] According to another specific embodiment of the utility model, the utility model discloses an embodiment of the utility model discloses that the recognition unit is arranged above the opening, and the recognition unit is used for identifying the color of the polymer particles on the feeding pipeline.

[0026] According to another specific embodiment of the utility model, the utility model discloses an embodiment of the utility model discloses that the recognition unit is arranged above the opening, and the recognition unit is used for identifying the color of the polymer particles on the feeding pipeline.

[0027] According to another specific embodiment of the utility model, the utility model discloses an embodiment of the utility model discloses that the recognition unit is arranged above the opening, and the recognition unit is used for identifying the color of the polymer particles on the feeding pipeline.

[0028] The dryer is used for drying and dehydrating the polymer particles, and the polymer particles are sent into the feeding pipeline after drying and dehydrating.

[0029] According to another specific embodiment of the utility model, the utility model discloses an embodiment of the utility model discloses that the recognition unit is arranged above the opening, and the recognition unit is used for identifying the color of the polymer particles on the feeding pipeline.

[0030] The underwater pelletizer can quickly and conveniently switch the material outlet, avoids waste of materials, and has simple operation and reduced labor intensity of workers. BRIEF DESCRIPTION OF DRAWINGS

[0031] Fig. 1 This diagram shows the structure of an underwater pelletizer according to an embodiment of the present invention.

[0032] Fig. 2 This diagram shows a structural schematic of the forming and conveying assembly of the underwater pelletizer according to an embodiment of the present invention;

[0033] Fig. 3 This diagram shows a structural schematic of the conveying assembly of the underwater pelletizer according to an embodiment of the present invention;

[0034] Fig. 4 This diagram shows the structural schematic of the conveying assembly and the spin-drying module of the underwater pelletizer according to an embodiment of the present invention. Detailed Implementation

[0035] The following specific embodiments illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. Although the description of this utility model will be presented in conjunction with preferred embodiments, this does not mean that the features of this utility model are limited to this embodiment. On the contrary, the purpose of describing the utility model in conjunction with the embodiments is to cover other options or modifications that may be derived based on the claims of this utility model. To provide a deep understanding of this utility model, many specific details will be included in the following description. This utility model may also be implemented without using these details. Furthermore, to avoid confusion or obscuring the focus of this utility model, some specific details will be omitted in the description. It should be noted that, without conflict, the embodiments and features in the embodiments of this utility model can be combined with each other.

[0036] It should be noted that in this specification, similar reference numerals and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0037] In the description of this embodiment, it should be noted that the terms "upper", "lower", "inner", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship that the utility model product is usually placed in during use. They are only for the convenience of describing the utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the utility model.

[0038] The terms “first”, “second”, etc., are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0039] In the description of the embodiments, it should also be noted that unless specifically defined and limited, the terms "set", "connected", "connected" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected, it can be mechanically connected, or it can be electrically connected, it can be directly connected, or indirectly connected through an intermediate medium, it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the embodiments can be understood according to the specific circumstances.

[0040] In order to make the purpose, technical scheme and advantages of the utility model clearer, the embodiments of the utility model will be described in further detail below with reference to the drawings.

[0041] Referring to Figs. 1 to 4 The utility model discloses an underwater pelletizer for making molten polymer into polymer particles, comprising a forming conveying assembly 31, which comprises an extrusion pressure boosting module for extruding molten polymer after pressure boosting and plasticizing into linear solution, a cutting assembly 2 comprising a water tank 21 and a cutter module 22 arranged in the water tank 21, wherein a constant temperature water flow flowing in a fixed direction is arranged in the water tank 21, the linear solution flows into the cutter module 22 in the water tank 21 after being extruded by the extrusion pressure boosting module, and the linear solution is cut into polymer particles by the cutter module 22 and flows with the constant temperature water flow, and a conveying assembly 3 comprising a feeding pipe 31 and a distribution pipe 32, wherein an opening 34 is arranged at the bottom of the feeding pipe 31, the distribution pipe 32 is communicated with the opening 34, a distribution paddle 4 is arranged at the opening 34, the polymer particles flow into the distribution pipe 32 from the feeding pipe 31 when the distribution paddle 4 is opened, and the polymer particles flow into the next process from the feeding pipe 31 when the distribution paddle 4 is closed.

[0042] In the embodiments, the extrusion pressure boosting module is internally provided with a high-precision screw structure, the screw is made of special alloy steel material, has excellent wear resistance and high temperature resistance, greatly prolongs the service life, reduces downtime and maintenance cost caused by frequent replacement of parts, ensures production continuity, and does not have deformation and other problems in the process of pressure boosting and plasticizing of molten polymer for a long time. The pitch and thread design can realize uniform pressure boosting of molten polymer, and ensure that the extruded linear solution can be stable in thickness and density. The optimized design of pitch and thread and the provision of pressure and temperature sensors make the pressure and temperature controllable during extrusion, avoid product quality problems caused by abnormal pressure or temperature, improve the forming quality of polymer particles, and improve the product qualification rate.

[0043] In an implementable embodiment, the extrusion booster module is also provided with a pressure sensor and a temperature sensor to monitor the internal pressure and temperature in real time. Once an abnormality occurs, the control system can be fed back in time to quickly adjust the corresponding parameters to ensure the continuity of work.

[0044] The water tank 21 is made of stainless steel and has good corrosion resistance to cope with long-term contact with various polymers and constant temperature water flow. The inner wall of the water tank 21 is polished to effectively reduce the adhesion of polymer particles during flow.

[0045] The stainless steel water tank 21 and the polishing of the inner wall fundamentally solve the corrosion and adhesion problems. On the one hand, long-term use will not cause rust and damage due to contact with polymers and water flow, ensuring the overall durability of the equipment. On the other hand, the smooth flow of polymer particles in the smooth inner wall environment will not be aggregated into blocks due to adhesion, which helps to smoothly carry out subsequent processes, reduces cleaning and maintenance costs, and improves production efficiency.

[0046] In an implementable embodiment, a flow regulating valve and a temperature regulating valve are installed at the water inlet of the water tank 21. By connecting with the external constant temperature circulating system, the flow and temperature of the constant temperature water flowing into the water tank 21 can be accurately controlled, so that the water flow can provide a good cooling environment for the cutter module 22 and ensure that the cut polymer particles can flow smoothly with the water flow. The setting of the flow regulating valve and the temperature regulating valve at the water inlet can accurately regulate the constant temperature water flow to create a suitable cutting environment for the cutter module 22. The appropriate water temperature not only avoids the accelerated wear of the cutter due to overheating and prolongs the service life of the cutter, but also ensures that the polymer particles will not deform due to high or low water temperature. At the same time, stable water flow can also timely remove the heat generated during cutting, making the cutting process more stable and efficient, and improving the cutting quality and appearance flatness of the particles.

[0047] The cutter of the cutter module 22 is made of high-strength hard alloy tool, which has extremely high sharpness and wear resistance, ensuring smooth cutting when cutting linear solute at high speed, so that the obtained polymer particles have regular shape and uniform size. The drive motor of the cutter module 22 is a variable frequency speed regulation motor, which can flexibly adjust the speed of the cutter according to different production needs, so as to accurately control the cutting size of the polymer particles. In addition, the cutter module 22 is also equipped with a tool wear detection device to monitor the wear of the tool in real time. Once the tool wear reaches a certain degree, the operator will be reminded in time to replace it, avoiding affecting the cutting quality.

[0048] High-strength cemented carbide cutters have sharpness and wear resistance, which can ensure smooth cutting, regular particle shape and uniform size during high-speed cutting, making the produced polymer particles of higher quality and meeting the strict requirements of various downstream applications for particle quality, such as uniform plasticization and molding in injection molding, extrusion and other processing technologies, and improving the performance and appearance quality of the final plastic products.

[0049] The variable frequency motor can flexibly adjust the cutting knife speed to meet the diversified demand for particle size in different production scenarios. The cutter wear detection device can monitor the cutter state in real time and timely remind the replacement to avoid cutting failure, particle size deviation and other problems caused by excessive wear of the cutter, further ensuring the stability of product quality, and also helping to reasonably arrange the cutter replacement plan and reducing the risk of affecting production progress due to accidental damage of the cutter.

[0050] The feeding pipe 31 is made of high-strength engineering plastic, which has good wear resistance and chemical corrosion resistance. The internal pipe diameter is accurately calculated to ensure that the polymer particles can smoothly pass through the pipe, while minimizing the accumulation and blockage of particles in the pipe. The bottom opening 34 of the feeding pipe 31 is designed reasonably, and the size of the opening 34 is matched with the pipe diameter of the distribution pipe 32 to ensure that the polymer particles can smoothly flow from the opening 34 to the distribution pipe 32. The use of high-strength engineering plastic has good wear resistance and chemical corrosion resistance, and can withstand the friction and chemical corrosion of polymer particles for a long time, reducing the frequency of pipe damage and replacement, and reducing the long-term cost of equipment operation. The reasonable pipe diameter design can effectively prevent particle accumulation and blockage, ensure the smoothness of the production process, avoid production interruption caused by pipe blockage, and improve the overall production efficiency.

[0051] The sealing performance of the connection method is good, which prevents particle leakage, maintains the cleanliness of the production environment, avoids material waste, and also meets the requirements of environmental protection and safety production, reducing the safety hazards and cleaning work caused by material leakage.

[0052] The material of the distribution pipe 32 is also a high-quality material with wear resistance and corrosion resistance, and the inner wall is smooth, which helps the polymer particles to pass through quickly. The connection between the distribution pipe 32 and the subsequent process is connected by a flange or a quick connector with good sealing performance to prevent particle leakage and ensure the cleanliness and efficiency of the entire production process.

[0053] The high-quality wear-resistant and corrosion-resistant material and the smooth inner wall make the polymer particles transmit quickly and smoothly in the pipe, reducing the friction loss between the particles and the pipe wall and the possible residue, ensuring the integrity and accuracy of material transportation, and facilitating the accurate reception of sufficient and qualified polymer particles by the subsequent process.

[0054] The material distribution push piece 4 is made of wear-resistant polymer material, has good flexibility and sealing performance, can quickly respond during opening and closing, and can accurately control the opening and closing angle, so as to ensure that the polymer particles accurately flow to the corresponding path according to the production requirements, and realize smooth transition whether entering the material distribution pipe 32 or flowing into the next process, thereby avoiding problems such as particle spilling or blockage.

[0055] The material distribution push piece 4 made of wear-resistant polymer material has good flexibility and sealing performance, and the quick opening and closing action and accurate angle control ensure that the polymer particles can be accurately distributed according to the production requirements, avoid material loss and blockage problems caused by particle spilling, improve the accuracy and efficiency of material distribution, ensure that each process can orderly and stably obtain the required polymer particles, and improve the coordination and reliability of the entire production process.

[0056] The above technical scheme can quickly and conveniently switch the material outlet, avoids waste of materials, and the whole process is simple to operate, thereby reducing the labor intensity of workers.

[0057] In an implementable embodiment, the extrusion pressurization module comprises:

[0058] The double-screw extruder 11, the polymer melt flows into the double-screw extruder 11 from the previous process, and the double-screw extruder 11 heats the polymer melt to a molten state and uniformly mixes the molten polymer;

[0059] The melt pump 12, the uniformly mixed molten polymer flows into the melt pump 12, and the melt pump 12 is used for pressurizing the molten polymer;

[0060] The screen changer 13, the molten polymer pressurized by the melt pump 12 flows to the screen changer 13, and the screen changer 13 is used for filtering the molten polymer;

[0061] The die head 14, the molten polymer pressurized by the melt pump 12 is extruded from the die head 14, and the die head 14 is provided with a die orifice, a plurality of through holes for extruding the molten polymer are arranged in an array at the cross section of the die orifice, and the molten polymer is extruded to form a linear solution through the through holes.

[0062] In this embodiment, the twin-screw extruder 11 adopts a twin-screw structure with co-rotating and close meshing, and the length-diameter ratio of the screw is carefully designed and generally falls within a specific reasonable range. The present application adopts a value between 20 and 40, which can ensure that the polymer melt has sufficient residence time in the conveying, shearing and mixing process of the screw, so that it is heated more uniformly and mixed more fully. The parameters such as the screw flight, screw groove shape and pitch of the screw are optimized and matched according to the characteristics of different polymers. For high-viscosity polymers, the present application adopts a design of gradually changing pitch and relatively deep screw groove to ensure smooth conveying and effective mixing of the material.

[0063] The co-rotating and close meshing twin-screw structure of the twin-screw extruder 11, as well as the reasonable length-diameter ratio and the design of parameters such as screw flight, enables the polymer melt to be fully mixed, and different batches and components of the polymer raw material can reach a highly uniform state under the shearing and mixing action of the screw.

[0064] The heating system is equipped with a segmented heating device, which is divided into multiple independent heating zones along the axial direction of the screw. The present application adopts 6 zones, each of which uses electric heating or hot oil circulation heating, and the temperature can be individually and accurately controlled. The temperature of each heating zone is monitored in real time by a temperature sensor and fed back to the control system, which accurately adjusts the heating power according to the set temperature curve to ensure that the polymer melt can be stably and accurately heated to the appropriate molten state, avoiding the problem of uneven material caused by local overheating or insufficient temperature.

[0065] The segmented heating system combined with temperature sensor feedback and precise control system adjustment can effectively avoid the situation of local overheating or insufficient temperature of the polymer melt. Precise temperature control not only ensures that the material can smoothly reach the molten state, but also maintains the material within the ideal processing viscosity range, making the material conveying in the screw more stable and the mixing more uniform, thereby ensuring the stability of the entire extrusion process, reducing production interruptions and product quality problems caused by temperature fluctuations, and improving production efficiency and product quality.

[0066] The transmission system uses a high-performance motor as the power source, which is connected to the screw through a speed reducer. The motor has good speed regulation performance and can flexibly adjust the speed of the screw according to the production process requirements. The speed range generally varies between a few dozen revolutions per minute and a few hundred revolutions per minute to meet the needs of different output and material mixing levels. At the same time, a torque protection device is also provided in the transmission system. When the screw encounters excessive resistance during operation and the torque exceeds the set value, the power transmission can be cut off in time to prevent the motor from being overloaded and damaged and the mechanical structure of the screw from being damaged, ensuring the safe and stable operation of the equipment.

[0067] The transmission system of the high-performance motor combined with the reducer and the good speed regulation performance enable the twin-screw extruder 11 to flexibly adjust the screw speed according to the characteristics of different polymers, different production scales, and specific process requirements. Whether it is large-scale production of general plastic particles or small-batch production of special formula polymer products, the processing time and mixing degree of the material can be optimized by adjusting the speed, greatly enhancing the adaptability of the equipment to different production processes and widening the application range of the equipment.

[0068] The torque protection device is set to cut off the power transmission in time when the screw encounters excessive resistance, avoiding motor overload damage and screw mechanical structure damage. This protection mechanism greatly prolongs the service life of the equipment, reduces the maintenance cost and downtime caused by accidental failure, and ensures the stable and reliable operation of the equipment for a long time, providing a strong guarantee for continuous production.

[0069] The melt pump 12 adopts a high-precision gear pump structure, and the gears are usually made of high-strength, high-temperature-resistant, and wear-resistant alloy steel. After precise machining process, the gears and the pump body cavity wall have a very small fitting gap, usually between tens of microns and hundreds of microns, which can effectively reduce the leakage of the melt and realize high-precision flow delivery and pressure boosting function. The pump body shell adopts a double-layer jacket design, which can be filled with constant-temperature heat-conducting oil and other media for temperature control to maintain the temperature stability of the melt during flowing through the pump body, avoiding the influence of temperature change on the viscosity of the melt and affecting the pressure boosting effect.

[0070] The high-precision gear pump structure and the very small fitting gap of the melt pump 12, combined with the feedback of the flow sensor and the variable frequency speed regulation control, can realize high-precision control of the flow and pressure boosting of the molten polymer. This means that the melt with stable pressure and flow can be accurately provided for the subsequent process according to the production requirements, ensuring that the polymer can be processed in a stable state in the subsequent filtering, extruding, and other links, avoiding the product quality differences caused by flow or pressure fluctuations, such as uneven particle size, which helps to improve the consistency and quality stability of the product.

[0071] The flow regulation and control are equipped with advanced flow sensors that monitor the flow of the melt in real time and feed the signal back to the control system. The control system combines the preset flow parameters to accurately control the output flow of the melt pump 12 by adjusting the speed of the motor. The motor uses variable frequency speed regulation technology, and the speed regulation accuracy can reach a high level, ensuring the stability of the flow during the pressure boosting of the molten polymer, so that it can be delivered to the screen changer 13 with stable pressure and flow.

[0072] The double jacket temperature control design of the pump body shell can effectively maintain the temperature stability of the melt during the flow through the pump body. Since the viscosity of the polymer is sensitive to temperature, stable temperature can ensure that the melt viscosity remains unchanged, thereby ensuring that the pressurization effect of the melt pump 12 is always in the best state, making the entire extrusion pressurization process more stable and efficient, while also helping to reduce problems such as polymer decomposition and aging caused by temperature changes, improving the performance and quality of the product.

[0073] At the inlet and outlet of the pump body and other key parts such as the gear shaft, high-performance sealing elements resistant to high temperature and chemical corrosion are used, such as a combination of polytetrafluoroethylene sealing rings and mechanical seals, which effectively prevent melt leakage and also facilitate daily maintenance and repair. The pump body also has a cleaning port to facilitate regular cleaning of any internal impurities, ensuring long-term reliable operation of the melt pump 12.

[0074] The use of high-performance sealing elements resistant to high temperature and chemical corrosion in key parts effectively prevents melt leakage, not only avoiding material waste and pollution to the production environment, but also reducing problems such as equipment corrosion and failure that may be caused by melt leakage. At the same time, the reserved cleaning port facilitates regular cleaning of internal impurities, making maintenance of the melt pump 12 more convenient, reducing long-term maintenance costs, and improving the overall operating efficiency and reliability of the equipment.

[0075] The screen changer 13 works on the principle of screen filtration, and according to the purity requirements of different polymers and the size of the impurity particles that may be contained, a screen with the appropriate mesh size is selected. The screen material is generally woven from stainless steel wire, with a mesh size ranging from several dozen to several hundred, for example, for some polyolefin polymers with high particle quality requirements, the present application uses a 200-mesh screen. The screen is installed in a replaceable filter basket inside the screen changer 13, making it easy to replace the screen regularly to maintain good filtration efficiency.

[0076] By selecting a screen with the appropriate mesh size to filter the molten polymer, impurity particles such as small pieces of polymer that have not completely melted and foreign matter can be effectively intercepted. This significantly improves the purity of the polymer melt entering the die 14, ensuring that the final polymer particles are free of impurities, and when used in high-end plastic product production or industrial applications with high purity requirements, it can improve the quality and performance of the product, reducing problems such as product defects and performance degradation caused by impurities.

[0077] It has two modes of manual and automatic screen replacement, especially the automatic screen replacement function can realize non-stop screen replacement during production, and quickly switch when the filter screen is blocked, which maximizes the reduction of the impact on production. This feature enables the device to run continuously for a long time, avoiding the loss of production efficiency caused by frequent shutdown to replace the filter screen. For large-scale and continuous polymer particle production, it greatly improves the production efficiency and ensures the timely and sufficient supply of high-quality products.

[0078] It has two modes of manual and automatic screen replacement, especially the automatic screen replacement function can realize non-stop screen replacement during production, and quickly switch when the filter screen is blocked, which maximizes the reduction of the impact on production. This feature enables the device to run continuously for a long time, avoiding the loss of production efficiency caused by frequent shutdown to replace the filter screen. For large-scale and continuous polymer particle production, it greatly improves the production efficiency and ensures the timely and sufficient supply of high-quality products.

[0079] In an implementable embodiment, high-precision pressure sensors are installed at the inlet and outlet of the screen changer 13 to monitor the pressure at the inlet and outlet in real time and calculate the pressure difference. When the pressure difference exceeds the normal range, on the one hand, it triggers a screen replacement prompt or an automatic screen replacement action, and on the other hand, the control system will adjust the speed of the melt pump 12 and other parameters as appropriate to prevent damage to the entire extrusion booster module and subsequent equipment due to excessive pressure, ensuring safe and stable operation of the device.

[0080] The pressure sensors at the inlet and outlet monitor the pressure difference in real time, and timely trigger screen replacement or related adjustment actions when the pressure difference exceeds the normal range, which not only ensures the filtering effect but also prevents damage to the entire extrusion booster module due to excessive pressure. The pressure monitoring and protection mechanism ensures the safety of the device components, reduces the risk of device failure caused by abnormal pressure, prolongs the service life of the device, and ensures the stability and order of the entire production process.

[0081] The die 14 is made of high-quality alloy steel and is cast as a whole, and is subjected to heat treatment and other processes to improve its strength and hardness while ensuring good heat conduction performance. The internal flow channel of the die 14 is designed in a streamline shape and optimized according to the principles of fluid mechanics, so that the molten polymer can be smoothly and uniformly distributed to each die when flowing through the die 14, avoiding uneven melt flow rate and pressure fluctuations, and ensuring consistent quality of the extruded thread-like solution.

[0082] The streamlined design of the internal flow channel of the die head 14 and the optimized fluid mechanics structure enable the molten polymer to be smoothly and uniformly distributed inside to each die orifice. In this way, the linear melt formed by the molten polymer extruded from each die orifice hole is highly consistent in flow rate, pressure, temperature, etc., thereby ensuring that the polymer particles obtained by subsequent cutting also have high consistency in size, shape, density, etc., improving the quality and appearance uniformity of the product, and better meeting the standardization requirements of various industrial applications for polymer particles.

[0083] The multiple arrayed through holes opened on the die orifice have a diameter determined according to the size specification of the required polymer particles, generally between zero point several millimeters and several millimeters, for example, the diameter of the through holes for producing common plastic particles may be about 1-3 millimeters. The machining precision of the through holes is extremely high, and precise drilling or electric spark machining processes are adopted to ensure that the cylindricity, straightness and surface roughness of the through holes meet the requirements, so that the molten polymer can be extruded in a regular shape to form a uniform linear melt. At the same time, in order to facilitate cleaning and maintenance, the die orifice is designed to be detachable, connected to the main body of the die head 14 by bolts or other connection methods, facilitating regular cleaning of the inside of the die orifice to prevent residual polymer accumulation from affecting the extrusion effect.

[0084] The high-precision through holes on the die orifice have strict requirements on diameter, cylindricity, etc., so that the molten polymer can be extruded to form a linear melt according to the accurately set size, thereby accurately controlling the size of the final polymer particles.

[0085] The die orifice is designed to be detachable, facilitating regular cleaning of its inside to prevent residual polymer accumulation from affecting the extrusion effect. This convenient maintenance feature can ensure that the die head 14 maintains a good working state for a long time, reduces the decline in extrusion quality caused by die orifice blockage, wear and tear, etc., prolongs the service life of the die head 14, at the same time, reduces the maintenance cost of the equipment, improves the overall operation stability and reliability of the equipment.

[0086] In an implementable embodiment, the linear melt is extruded into the water tank 21 by the die head 14 and cooled and formed in the water tank 21, and the water tank 21 further includes: a water pump 23 including radial nozzles and tangential nozzles, the radial nozzles being arranged towards the cutter module 22 for flushing the cutter module 22 to prevent polymer particle adhesion; the tangential nozzles are used to push the water in the water tank 21 to flow in a predetermined direction, so as to send the polymer particles in the predetermined direction to the feeding pipe 31 to flow into the next process; a heat exchanger for keeping the water in the water tank 21 at a constant temperature within a predetermined temperature threshold.

[0087] In this embodiment, the water pump 23 is made of corrosion-resistant and high-strength stainless steel material to ensure that it will not rust or corrode in the long-term contact with water and possible trace amounts of polymer, thereby ensuring the service life and stable operation of the water pump 23. The impeller inside is made of precision casting process, and the shape of the blade is optimized by fluid mechanics simulation, so that the impeller can produce efficient and stable water flow when rotating, reducing water turbulence and improving water transportation efficiency and energy conversion efficiency.

[0088] According to the volume of the water tank 21 and the production scale of the entire underwater pelletizer, the power and flow parameters of the water pump 23 are reasonably selected to ensure that a strong enough water flow is generated to meet the needs of flushing the cutter module 22 and pushing the polymer particles to flow. At the same time, the water pump 23 is equipped with multiple speed regulation functions, which can be flexibly adjusted by the control system according to the actual production situation to adapt to different polymer materials, different cutter speeds and different production stages.

[0089] The radial nozzles are evenly distributed in a ring around the cutter module 22, with 8 nozzles, which are optimally configured according to the size and structure of the cutter module 22. The outlet axis of each nozzle forms a specific inclination angle with the plane where the cutter blades are located, and the inclination angle of the present application is 30. After repeated tests and verification, the water flow sprayed from the nozzle can flush the cutter module 22 with the best impact force and coverage, ensuring that the polymer particles on the cutter blades can be effectively flushed off and preventing adhesion.

[0090] The caliber size of the radial nozzle is determined according to the total flow of the water pump 23, and the present application is 15. A flow regulating device is provided inside the nozzle, and the opening of the throttle valve core in the regulating device can accurately control the water flow of each nozzle, so that the water flow of each nozzle is uniform and stable, ensuring consistent flushing effect on the cutter module 22 and avoiding local flushing deficiency that causes the cutter to adhere to the polymer particles, affecting the cutting quality and efficiency.

[0091] The nozzle is made of ceramic material or hard alloy material that is wear-resistant, corrosion-resistant and has good smoothness. Such material not only can withstand long-term flushing and wear of water flow, but also can reduce the possibility of polymer particles adhering and accumulating on the inner wall of the nozzle. At the same time, a fine filter screen is provided at the inlet of the nozzle, with a mesh size of 80-120, which is used to intercept impurity particles that may be carried in the water to prevent them from entering the nozzle and causing blockage, ensuring that the nozzle can continuously and stably spray water flow for flushing operation.

[0092] The tangential nozzles are installed on specific positions of the wall of the water tank 21, arranged along the tangential direction of the inner wall of the water tank 21, and the installation height of all the tangential nozzles is kept consistent, ensuring that the water flow sprayed by them can jointly act to push the water in the water tank 21 to form a stable annular flow in the preset direction. The angle deviation of the outlet direction of the nozzles from the tangential direction of the inner wall of the water tank 21 is controlled within a very small range, so as to ensure that the water flow can smoothly flow along the inner wall of the water tank 21 and drive the polymer particles in the water tank 21 to move in order in the intended direction.

[0093] An adjustable guide vane is arranged at the outlet of each tangential nozzle. By adjusting the angle of the guide vane, the spray direction and flow rate distribution of the water flow can be changed, thereby precisely controlling the overall flow state of the water in the water tank 21. In combination with the speed regulation function of the water pump 23, the flow rate of the water in the water tank 21 can be maintained within a suitable range. For example, for common polymer particle production, the flow rate of the water is generally controlled to be between 0.5-1.5 meters per second. In this way, it can be ensured that the polymer particles are smoothly sent to the feeding pipe 31 along with the water flow, and at the same time, excessive collisions between the particles or accumulation and blockage at the inlet of the pipe can be avoided due to too high water flow speed.

[0094] The multiple tangential nozzles cooperate with each other, and their layout and spray parameters are optimized through computational fluid dynamics simulation analysis, so as to ensure that a uniform, stable and required flow field is formed in the water tank 21. By simulating the flow field under different nozzle numbers, spacings, spray angles and flow rates, the best configuration scheme is adjusted, so that the water in each region of the water tank 21 can flow in the preset direction, avoiding the occurrence of water flow dead zones or local turbulent flow and other conditions that are not conducive to the transportation of polymer particles, and improving the efficiency and accuracy of particle transportation.

[0095] According to the accuracy requirements of water temperature control in the water tank 21, the heat exchange efficiency requirements and the operating environment of the overall equipment, a suitable heat exchanger is selected, and heat exchange is performed through heat conduction by using the water in the water tank 21 and the external constant-temperature medium, so that the water temperature in the water tank 21 is maintained within the preset temperature threshold. High-precision temperature sensors are uniformly arranged at different positions in the water tank 21 to monitor the water temperature in real time, and the temperature data is fed back to the control system. The measurement accuracy of these temperature sensors can reach ±0.1℃ or even higher, which can accurately reflect the subtle changes of the water temperature in the water tank 21, and provide reliable data support for accurate control.

[0096] The control system compares and analyzes the water temperature information fed back by the temperature sensors with the preset temperature threshold. When the water temperature is higher than the preset upper limit value, the control system adjusts the flow rate, flow speed or switches to a low-temperature medium of the external constant-temperature medium in the heat exchanger to accelerate heat dissipation and reduce the water temperature. Conversely, when the water temperature is lower than the preset lower limit value, the heat input is increased by corresponding adjustment measures to increase the water temperature.

[0097] In an implementable embodiment, the cutter module 22 comprises a moving cutter unit including a moving cutter connected with a driving motor through a coupling, and the moving cutter is driven to rotate by the driving motor to cut the linear solution into polymer particles; a radial nozzle is arranged towards the moving cutter; a fixed cutter unit including a fixed cutter is fixedly installed on the opposite side of the moving cutter to form a shearing gap with the moving cutter for completely cutting the linear solution; an adjusting mechanism including a cutter shaft and an adjusting component connected with the cutter shaft, the moving cutter is installed on the cutter shaft, and the adjusting component can push the cutter shaft to move along the extension direction of the cutter shaft to adjust the gap between the moving cutter and the fixed cutter; and a pressure sensor arranged on the moving cutter for detecting the contact pressure when each blade of the moving cutter cuts.

[0098] In this embodiment, the moving cutter is made of a hard alloy material with high strength, high hardness and wear resistance, which has excellent wear resistance and impact resistance, can maintain the sharpness of the cutting edge during long-time high-speed cutting of the linear solution, reduce wear and tear, and prolong the service life. The cutting edge part of the moving cutter is treated by a precise grinding process, and the roughness of the cutting edge can reach Ra0.8 - Ra1.6μm, which ensures that a neat and smooth cut can be formed on the linear solution during cutting, and the edges of the generated polymer particles are regular and uniform in size.

[0099] The shape of the moving cutter is usually designed as a disc or a long strip, and the specific shape is determined according to the overall layout of the cutter module 22 and the cutting requirements. The disc-shaped moving cutter is convenient for high-speed rotary cutting, and has better balance during rotation; the long strip-shaped moving cutter is more suitable for occasions requiring larger cutting width. The thickness of the moving cutter is generally between 5 - 20mm, and the length of the cutting edge is designed according to the cutting width requirement. For example, under the common industrial production scale, the length of the cutting edge may be between 100 - 500mm, and the angle of the cutting edge (such as the rake angle, the relief angle, etc.) will be optimized according to the characteristics of the polymer material. For softer polymer materials, the rake angle of the cutting edge can be appropriately increased to reduce the cutting resistance and improve the cutting efficiency.

[0100] The coupling connecting the moving cutter and the driving motor is selected to be a flexible coupling, which has good buffering and damping performance, can effectively absorb the impact force generated by the moving cutter during cutting and the vibration that may occur during the operation of the motor, protect the shaft components of the moving cutter and the motor, and prevent problems such as shaft fatigue damage and bearing wear caused by rigid connection. The material of the coupling is generally high-strength alloy steel, which is processed by a precise machining process to ensure the matching precision of the coupling with the moving cutter shaft and the motor shaft, and the coaxiality deviation is controlled within a very small range (generally not more than ±0.05mm), which ensures the stability and high efficiency of power transmission, so that the moving cutter can rotate stably and uniformly under the drive of the motor for cutting operation.

[0101] The driving motor preferably uses a high-performance variable frequency speed regulation motor, which can flexibly adjust the speed according to different production process requirements, and has a wide speed regulation range, for example, it can be accurately regulated between 500-5000 revolutions per minute. This speed regulation function enables the cutter module 22 to adapt to the cutting needs of different linear polymer melts, and for polymers with high viscosity and high toughness, the speed can be appropriately reduced to ensure cutting quality; for polymers that are easy to cut, the speed can be increased to improve production efficiency. At the same time, the motor has good overload protection capability, when encountering excessive resistance during cutting, the motor current exceeds the rated value, it can automatically cut off the power or reduce the output power to prevent the motor from burning out and ensure the safe operation of the equipment.

[0102] The motor is installed on a stable motor base made of cast iron or high-strength steel, which is subjected to aging treatment to eliminate internal stress, and has sufficient rigidity and stability to withstand the vibration of the motor during operation and the cutting force transmitted to it. The motor base is connected to the water tank 21 or the entire pelletizer frame through bolts, and vibration isolation measures such as shock-absorbing rubber pads are used at the connection site to further reduce the impact of motor vibration on the entire equipment, ensuring that the equipment remains stable during operation and avoiding problems such as reduced cutting accuracy and loose equipment parts caused by vibration.

[0103] The fixed knife also uses high-strength and wear-resistant hard alloy material, which is matched with the moving knife material to ensure that the wear degree of the two is similar during long-term shearing cooperation, maintaining a stable shearing gap. The surface of the fixed knife is treated with a special coating to further improve its surface hardness and wear resistance, while reducing the adhesion of polymer particles on its surface, preventing polymer particles from sticking to the fixed knife during cutting, affecting the cutting effect and subsequent particle transport.

[0104] The fixed knife is fixedly installed on the opposite side of the moving knife through an accurate positioning mechanism, and the mounting seat is made of high-strength stainless steel material and is precisely machined to ensure that the flatness of the fixed knife mounting plane is within a very small range, so that the fixed knife and the moving knife can accurately form the required shearing gap, and the position remains stable during equipment operation without displacement due to vibration or other external factors, ensuring cutting accuracy and stability. The fixed knife and the mounting seat are connected by bolts and are precisely positioned with a positioning pin, which facilitates installation, disassembly, and later adjustment and maintenance.

[0105] The shearing gap between the moving knife and the fixed knife is one of the key factors affecting the cutting quality. Its initial setting value is determined according to the characteristics of the polymer material and the size of the required polymer particles, and is generally between 0.1-1mm. For softer polymer materials, the shearing gap can be appropriately increased to avoid polymer clogging in the gap; while for higher hardness and smaller particle size, the gap needs to be adjusted to ensure that the linear solution can be completely and neatly cut. In the production process, as the cutter wears, the shearing gap will change, and needs to be adjusted in time through the adjusting mechanism to maintain the best cutting state. A suitable shearing gap can ensure that the linear solution is cleanly cut into regular-shaped and uniform-sized polymer particles when it passes through the shearing action of the moving and fixed knives.

[0106] The knife shaft is made of high-strength alloy steel and is subjected to heat treatment processes such as quenching and tempering to improve its overall strength and hardness, while also having good toughness to withstand the centrifugal force and cutting force of the moving knife during high-speed rotation cutting. The outer diameter of the knife shaft is designed according to the installation requirements of the moving knife and the required load capacity, generally between 20-50mm, and its surface is precisely ground to control the cylindrical and linear errors within a very small range, providing a stable installation foundation for the moving knife and ensuring its coaxiality and balance during rotation.

[0107] The moving knife is installed on the knife shaft by key connection or interference fit. When key connection is used, a suitable flat key or half-round key is selected, and the key and keyway have high precision to ensure that the moving knife can rotate synchronously with the knife shaft and will not loosen during torque transmission. For interference fit, the interference amount is determined through precise calculation and process test to ensure the tight connection of the moving knife and the knife shaft, and facilitate the disassembly operation when the moving knife needs to be replaced. The use of appropriate tooling equipment can achieve smooth disassembly and installation of the moving knife.

[0108] The adjusting component mainly consists of a screw-nut mechanism, a guide rail and block mechanism, and a driving device. The screw-nut mechanism uses high-precision ball screws, which are rotated to drive the nut to move axially along the screw shaft, and then push the knife shaft connected to the nut to move. The guide rail and block mechanism provides precise guidance for the movement of the knife shaft, ensuring that the knife shaft can only move linearly along its extension direction. The straightness and parallelism errors of the guide rail are controlled within a very small range, and low-friction wear-resistant materials are used between the block and the guide rail to ensure the smoothness and accuracy of the knife shaft movement.

[0109] In an implementable embodiment, the driving device generally adopts the form of an electric push rod or a hand wheel, etc. The electric push rod is driven by a motor to rotate the screw rod, and has the advantages of high automation degree and high adjustment precision, and can be accurately controlled by the control system according to the data fed back by the pressure sensor or the preset adjustment parameters. The hand wheel is suitable for manual fine adjustment, and the operator can manually rotate the hand wheel to adjust the position of the cutter shaft according to actual observation and experience, so as to finely adjust the gap between the moving cutter and the fixed cutter. During the adjustment process, the moving distance of the cutter shaft is displayed in real time by a dial or a displacement sensor, etc., so that the operator can accurately master the adjustment amount of the gap and ensure that the adjustment precision meets the cutting requirements.

[0110] The pressure sensor installed on the moving cutter selects a high-precision and high-sensitivity miniature strain gauge type pressure sensor, the measurement range of which is determined according to the maximum contact pressure that the moving cutter may bear during the cutting process, and is generally between 0-500N, which can accurately detect the slight pressure change of each blade of the moving cutter during cutting. The sensor has good anti-interference ability and can work stably in a humid, vibrating and electromagnetically interfering industrial environment, ensuring accurate transmission of the pressure signal.

[0111] The pressure sensor is installed in the cutter body or other key stress parts of the moving cutter, and is installed in an embedded manner to ensure that the sensor is closely attached to the moving cutter and can truly reflect the stress condition of the moving cutter during cutting. During installation, the contact surface between the sensor and the moving cutter is finely polished and flattened to ensure good contact between them and avoid measurement errors caused by improper installation. At the same time, the lead wire of the sensor adopts a shielded cable and is protected against water and moisture, and is led out along the cutter shaft or other safe path and connected to the signal acquisition module of the control system to prevent the signal from being interfered by the outside world.

[0112] During the cutting process, the pressure sensor collects the contact pressure data of each blade of the moving cutter in real time and transmits these data to the control system in the form of electrical signals. The control system analyzes and processes these pressure signals in real time, such as drawing a pressure change curve, observing the fluctuation of the pressure in each cutting cycle, comparing with the preset normal pressure range, and judging whether the cutting process is normal. If the pressure abnormally fluctuates, such as suddenly increasing beyond the set threshold, it may mean that the tool is severely worn, the shearing gap is too small, or there are foreign matters in the linear solution, etc., and the control system will promptly issue an alarm to prompt the operator to check and handle.

[0113] The cutter module 22 parts can work together to achieve efficient and accurate cutting of linear melt. Through reasonable structure design, precise adjustment mechanism and reliable pressure monitoring means, high-quality and uniform size polymer particles can be produced, the service life of the cutter is prolonged, the stable operation of the equipment is ensured, and the strict requirements of different industrial production scenes on the cutting performance of the underwater cutter are met.

[0114] In an implementable embodiment, the feeding pipe 31 is provided with an identification unit 33, which is arranged above the opening 34. The identification unit 33 is used to identify the color of the polymer particles on the feeding pipe 31.

[0115] In this embodiment, the optical detection probe in the identification unit 33 continuously monitors the color of the polymer particles flowing above the opening 34 in the feeding pipe 31, and the signal processing module analyzes the collected particle color information in real time. The preset color reference value and the corresponding color change threshold value are used to determine whether the current material color has changed. For the production of a specific color of polymer particles, the RGB color channel value range corresponding to white is set as the reference value in the control system in advance, and a reasonable color change threshold value is also set. When the RGB value of the particle color detected exceeds the range defined by the reference value and the threshold value, it is determined that the current material color has changed, and the identification unit 33 generates a trigger signal at this time.

[0116] The trigger signal generated by the identification unit 33 is an electrical signal, usually in a standard digital signal format, which is transmitted to the control system along a predetermined line through a shielded cable. The control system is equipped with a dedicated signal receiving port and a corresponding signal processing circuit, which can accurately receive and identify the trigger signal. After receiving the trigger signal, the control system will immediately start the corresponding control program to control the opening or closing action of the material distribution paddle 4, ensuring that the entire material distribution process responds to color changes in a timely and accurate manner.

[0117] The opening and closing actions of the material distribution paddle 4 are realized by a dedicated driving mechanism. The electric push rod is composed of a motor, a screw nut transmission mechanism, etc. After receiving the action instruction from the control system, the motor drives the screw to rotate, which in turn drives the material distribution paddle 4 connected to the nut to move in a set direction, realizing the opening or closing action. The pneumatic push rod uses compressed air as a power source, and controls the movement of the piston in the cylinder through an electromagnetic valve, so that the material distribution paddle 4 connected to the piston performs the corresponding action. Both driving methods have sufficient driving force and precision, which can ensure the stable and reliable operation of the material distribution paddle 4 in frequent opening and closing operations.

[0118] The action accuracy of the distribution pushing piece 4 is high, and the control accuracy of the opening and closing angle can reach within ±1°, so as to ensure that the polymer particles can accurately flow to the corresponding path according to the requirements. In terms of response time, the response time of the whole process is generally controlled within 3 seconds from the triggering of the signal of the identification unit 33 to the completion of the opening or closing action of the distribution pushing piece 4, so that the color change of the material can be quickly responded, and problems such as inaccurate material distribution or blockage caused by slow action can be avoided. At the same time, in order to ensure the stability of the action of the distribution pushing piece 4, the driving mechanism is also provided with a buffer device, such as a spring buffer at the end of the electric push rod or a hydraulic buffer element at the end of the stroke of the pneumatic push rod, so as to reduce the impact force of the distribution pushing piece 4 when reaching the limit position and prolong the service life of the equipment.

[0119] The state under the normal production process is as follows:

[0120] In the normal production process, when the identification unit 33 does not detect the color change of the polymer particles, i.e. is not triggered, the control system defaults that the distribution pushing piece 4 is in the closed state. The polymer particles will naturally flow into the next process along the feeding pipe 31, and the whole process continues until the identification unit 33 detects the color change signal. During this period, the control system will regularly patrol the working state of the identification unit 33 and the position of the distribution pushing piece 4, to ensure that each component is in normal operation, and if an abnormal condition is found, an alarm will be sent to the operator for processing in time.

[0121] Once the identification unit 33 detects the color change of the material and triggers the signal, the control system will send an opening instruction to the driving mechanism of the distribution pushing piece 4 according to the preset logical sequence, and the driving mechanism will drive the distribution pushing piece 4 to open rapidly after receiving the instruction, so that the polymer particles can smoothly flow from the feeding pipe 31 to the distribution pipe 32. During the opening process of the distribution pushing piece 4, the control system will monitor the opening angle in real time, and through the angle information fed back by the angle sensor installed on the driving mechanism, it can ensure that the distribution pushing piece 4 accurately reaches the set opening angle, so as to ensure that the material can smoothly flow into the distribution pipe 32. When the color returns to normal and the identification unit 33 is no longer triggered, the control system will send a closing instruction to drive the distribution pushing piece 4 to close, so that the subsequent material can flow into the next process again, and the cycle is repeated, so as to realize the function of accurately distributing the polymer particles according to the color change of the material.

[0122] The spin-drying module 5 includes a centrifugal dryer 53, which includes a rotating drum 51. The constant-temperature water flow drives the polymer particles to flow into the rotating drum 51, and the rotating drum 51 rotates to separate the water flow and the water on the polymer particles. The polymer particles after water separation are sent to the next process by the rotating drum 51 through the feeding pipe 31.

[0123] A vibrating screen 52 is also included, and the polymer particles are fed into the vibrating screen 52 through the feeding pipe 31 by the rotating drum 51, and the vibrating screen 52 vibrates and sorts the polymer particles;

[0124] A dryer 53 is further included, and the polymer particles screened by the vibrating screen 52 flow into the dryer 53, and the polymer particles are dried by the dryer 53 and then fed into the feeding pipe 31.

[0125] In the embodiment, the rotating drum 51 is made of high-strength and corrosion-resistant stainless steel material as a whole, which can resist corrosion in the environment of long-term contact with water and polymer particles, and ensure the service life and stability of the equipment. The shape of the rotating drum 51 is generally cylindrical, and the inner wall thereof is finely polished, and the surface roughness can reach Ra0.8-Ra1.6μm. Such a smooth surface helps to reduce the adhesion of polymer particles during rotation, so that the polymer particles can be more smoothly thrown out under the action of centrifugal force, and the subsequent cleaning and maintenance of the inside of the rotating drum 51 are also facilitated.

[0126] The diameter and length of the rotating drum 51 are determined according to the production scale of the underwater pelletizer and the processing capacity of the polymer particles. In order to withstand the huge centrifugal force generated during high-speed rotation, the rotating drum 51 is provided with a reinforcing rib structure, which is reasonably distributed along the circumferential direction and axial direction of the rotating drum 51. The reinforcing rib structure increases the overall strength of the rotating drum 51, and does not excessively affect the flow and throwing effect of the particles. The motor driving the rotating drum 51 is preferably a three-phase asynchronous motor or a variable frequency motor with high power, high speed and good speed regulation performance. The variable frequency motor can flexibly adjust the speed of the rotating drum 51 according to different material characteristics, water content and production stages, accurately control the output frequency of the motor through the frequency converter, realize stepless adjustment of the speed, and make the centrifugal drying process more accurate and efficient.

[0127] The motor and the rotating drum 51 are connected by belt transmission or direct transmission. The belt transmission has the advantages of buffering and damping, overload protection, and easy installation and maintenance. By selecting high-strength and wear-resistant belts (such as triangular belts or synchronous belts) and reasonably designing the diameter ratio of the belt pulleys, a suitable transmission ratio can be achieved to meet the speed requirements of the rotating drum 51.

[0128] The feeding port of the centrifugal dryer 53 is arranged at the upper part of one side of the rotating drum 51, and the opening 34 is optimized in size and shape to ensure that the constant-temperature water flow can smoothly carry the polymer particles into the rotating drum 51, and to prevent liquid splashing or material blockage during feeding. A flow regulating valve is provided at the feeding port, which can adjust the feeding flow of the constant-temperature water flow and the polymer particles in real time according to the liquid level in the rotating drum 51 and the material processing speed, so as to ensure that the amount of material entering the rotating drum 51 is stable and uniform, and to maintain good centrifugal drying operating conditions.

[0129] The discharge port is located at the other side of the bottom of the rotating drum 51 and is connected with the feeding pipe 31. The discharge port is designed with a large diameter to avoid blockage caused by the accumulation of polymer particles. Inside the discharge port, a spiral guide vane is arranged, which rotates in the opposite direction of the rotating drum 51. When the rotating drum 51 rotates, the polymer particles are thrown to the inner wall of the rotating drum 51 under the action of centrifugal force. In the process of sliding along the inner wall to the discharge port, the spiral guide vane can further push the particles to flow out smoothly, preventing the particles from accumulating at the discharge port and ensuring the continuity and smoothness of the discharge.

[0130] A drainage hole or a drainage groove is arranged around the bottom of the rotating drum 51 for draining the thrown water out of the rotating drum 51. The diameter of the drainage hole is moderate, which can ensure that the water is quickly drained and prevent the polymer particles from leaking out of the drainage hole. Generally, the diameter is between 5-15 mm, and the drainage holes are evenly distributed to ensure that the water in each area of the rotating drum 51 can be drained in time. The drainage groove is arranged along the circumferential direction of the bottom of the rotating drum 51 and has a certain slope to facilitate the flow of water to the drainage port after collection. The drainage port is connected to the external drainage collection device through a pipe to facilitate subsequent treatment or recycling of the drained water.

[0131] A flow sensor and a liquid level sensor are installed on the drainage pipe. The flow sensor monitors the flow rate of the drainage in real time, and the liquid level sensor monitors the liquid level in the rotating drum 51. Through the data feedback of these sensors, the control system can judge the drainage effect of the centrifugal drying process. If it is found that the drainage is not smooth or the liquid level is abnormally high, an alarm will be sent out in time and appropriate measures will be taken, such as adjusting the rotating speed of the rotating drum 51, checking whether the drainage hole is blocked, etc., to ensure the normal operation of the water separation process.

[0132] The screen body of the vibrating screen 52 is made of high-strength carbon steel or stainless steel material and is processed by welding and reinforcement, etc. to have sufficient rigidity and stability to withstand the impact force in the vibration process and the weight of the material. Multiple layers of screens with different mesh sizes are installed inside the screen body. The screen material is generally made of stainless steel wire knitting. According to the size requirements of the polymer particles and the screening accuracy, appropriate mesh size is selected. For example, the uppermost layer of screen may have a lower mesh size (such as 10-20 mesh) for preliminary removal of larger impurities or agglomerated particles, the middle layer of screen may have a moderate mesh size (such as 20-40 mesh) for particle classification and screening, and the lowermost layer of screen may have a higher mesh size (such as 40-60 mesh) for ensuring that the particles entering the dryer 53 meet the requirements. Each layer of screen is firmly installed in the screen body through a special clamp or slot structure for easy disassembly and replacement.

[0133] The vibrating screen 52 is equipped with a vibrator as a vibration source, which can be selected from a vibrating motor or an eccentric block vibrator, etc. The vibrating motor has the advantages of simple structure, convenient installation, easy adjustment of vibration frequency and amplitude, etc. By changing the speed of the motor and the weight, eccentricity of the eccentric block, etc., the vibration frequency (generally between 1000-3000 times / minute) and amplitude (generally between 1-5mm) of the vibrating screen 52 can be adjusted, so that the polymer particles can be well sorted on the screen. The eccentric block vibrator drives the screen body to vibrate by the centrifugal force generated by the rotating eccentric block, and the vibration direction and intensity can be accurately controlled by adjusting the installation angle and size of the eccentric block, ensuring that the screen body can produce uniform and stable vibration, and promoting the effective layering and screening of the polymer particles on the screen.

[0134] The vibrating screen 52 is installed on the ground or equipment support through an elastic support device, which usually uses rubber springs or metal coil springs, etc. They can provide good elastic support and damping effect, reducing the vibration transmission of the vibrating screen 52 to the surrounding equipment and ground during operation. At the same time, damping measures such as buffer rubber pads are also provided around the base of the vibrating screen 52 to further absorb and isolate vibration, ensuring the smooth operation of the entire equipment, avoiding problems such as component loosening, damage and affecting screening accuracy caused by excessive vibration.

[0135] The feed inlet of the vibrating screen 52 is located at the upper part of one end of the screen body, and the feeding method can adopt chute feeding or vibrating feeder feeding, etc. The chute feeding structure is simple, and by designing a reasonable chute slope and shape, the polymer particles sent from the centrifugal dryer 53 can flow into the vibrating screen 52 naturally by gravity, but in order to ensure the uniformity of feeding, guide plates or other structures can be arranged inside the chute to disperse and guide the material flow. The vibrating feeder feeding is more precise, which drives the feeding trough to vibrate through the vibration motor, so that the material is uniformly fed into the vibrating screen 52 according to the set flow rate and speed, which is suitable for occasions with high requirements for feeding uniformity. By adjusting the parameters of the vibration motor, the feeding speed and amount can be accurately controlled.

[0136] A plurality of discharge outlets are arranged below the screen body of the vibrating screen 52, respectively corresponding to the material outlets after being screened by different mesh screens. For example, larger particle impurities screened by the upper layer screen are discharged and collected through one discharge outlet, polymer particles within a certain size range screened by the middle layer screen flow out through another discharge outlet, and qualified and more fine particles screened by the lowermost layer screen enter the dryer 53 through the corresponding discharge outlet. Each discharge outlet is connected to the corresponding collection device or next process equipment through a pipeline or chute, ensuring that different types of materials can be accurately classified, collected and transported, facilitating subsequent processing and utilization.

[0137] The dryer 53 can be selected from a hot air circulating dryer 53, a vacuum dryer 53, and the like. The specific selection is determined according to the characteristics of the polymer particles, the water content requirement, and the production scale, and the like. The hot air circulating dryer 53 forms hot air by heating air, and uses the hot air to fully contact the polymer particles to evaporate the water, thereby achieving the purpose of dehydration. It has the advantages of simple structure, low cost, and fast drying speed, and is suitable for drying most conventional polymer particles. The vacuum dryer 53 is dried in a vacuum environment, which reduces the boiling point of water, so that the water can be quickly evaporated at a lower temperature. It is particularly suitable for drying polymer particles that are sensitive to temperature, easy to oxidize, or require high-precision dehydration. Although the equipment cost is relatively high, it can ensure the drying quality and product performance.

[0138] Taking the hot air circulating dryer 53 as an example, it is internally provided with multiple layers of drying trays or drying chambers. The polymer particles are uniformly distributed in these trays or chambers to increase the contact area and contact time of the particles with the hot air, thereby improving the drying efficiency. The air duct design inside the dryer 53 is optimized through computational fluid dynamics (CFD) simulation to ensure that the hot air can uniformly blow through each layer of trays or chambers, so that the polymer particles in each area can be dehydrated under the same drying conditions, avoiding local uneven drying. At the same time, ventilation openings are provided at the top and bottom of the dryer 53. The top ventilation opening is used to exhaust humid air containing water vapor, and the bottom ventilation opening is used to introduce fresh hot air, forming a good hot air circulation system to ensure the continuous drying process.

[0139] The heat source of the hot air circulating dryer 53 can be selected from electric heating, steam heating, or gas heating. The electric heating method has the advantages of fast heating speed, precise temperature control, and clean and pollution-free. It converts electrical energy into heat energy through electric heating wires or heating pipes, and then transfers the heat to the air through a heat exchanger to form hot air. Steam heating uses steam provided by the steam pipe network in the factory as a heat source, and heats the air through a heat exchanger. This method has a relatively low cost and is suitable for occasions with steam supply. Gas heating uses the heat generated by the combustion of natural gas, liquefied gas, and the like to heat the air. It has a large heating power and is suitable for large-scale drying applications. Regardless of the type of heat source, a temperature sensor and a temperature control system are provided to monitor the temperature of the hot air in real time, and to accurately control the output power of the heat source according to the preset drying temperature requirement, so that the temperature of the hot air is maintained within a suitable range (for example, between 50-150°C, which is determined according to the characteristics of the polymer particles). This ensures the drying effect while avoiding damage to the polymer particles caused by excessive temperature.

[0140] The feeding port of the dryer 53 is connected with the discharge port of the vibrating screen 52, and the feeding mode can adopt screw conveyor feeding or vibrating feeder feeding, etc., to ensure that the polymer particles screened from the vibrating screen 52 can enter the dryer 53 uniformly and stably. The screw conveyor advances the material through the rotation of the screw blade, and the conveying speed can be controlled by adjusting the motor speed, so that continuous and quantitative feeding can be realized, the material in the dryer 53 is uniformly distributed, and the situation of uneven drying caused by local accumulation is avoided. The vibrating feeder relies on vibration to make the material flow into the dryer 53 uniformly, and the feeding amount can be accurately controlled by adjusting the vibration parameters to meet the feeding requirements of different production scales and drying requirements.

[0141] The discharge port of the dryer 53 is located at the bottom or side position, and a flow regulating valve is arranged at the discharge port. The discharge speed can be adjusted according to the material requirements of the subsequent process and the drying progress in the dryer 53. Online moisture detection instruments can also be installed near the discharge port to detect the water content of the discharged polymer particles in real time. The detection data is fed back to the control system, and only when the water content reaches the preset qualified standard, the particles will be sent to the next process through the feeding pipe 31. If the water content does not meet the requirements, the drying parameters of the dryer 53 (such as prolonging the drying time, increasing the hot air temperature, etc.) can be adjusted through the control system to continue the drying process, so as to ensure that the quality of the final product meets the requirements.

[0142] In an implementable embodiment, an observation window is opened on one side of the feeding pipe 31, and transparent glass is installed on the observation window. The observation window is used for visual inspection of the color of the polymer particles.

[0143] In this embodiment, the frame of the observation window is made of stainless steel material which is firm and corrosion-resistant, so as to ensure that it can be firmly installed on the side wall of the feeding pipe 31 and withstand external forces such as material flow and possible vibration in the pipe; the inner edge of the frame is finely chamfered to avoid sharp corners and prevent damage to the transparent glass during installation and use. The shape of the frame is usually adapted to the curvature of the feeding pipe 31 to ensure close fitting. The frame can be fixed on the feeding pipe 31 by welding or bolt connection. The welding method can achieve better sealing and integrity, while the bolt connection is convenient for subsequent disassembly and maintenance. The specific method can be selected according to actual needs.

[0144] The transparent glass installed on the observation window is made of special glass with high transparency, high strength, and good wear resistance and chemical corrosion resistance, such as borosilicate glass. This glass not only clearly presents the color of the polymer particles in the feeding pipe 31 for visual inspection, but also remains stable in performance under long-term contact with polymer particles and some chemicals that may exist, temperature changes, and other working conditions, and is not prone to problems such as blurring and breaking. The thickness of the glass is determined according to the size of the observation window and the internal pressure of the pipe, and is generally between 5-15 millimeters to ensure sufficient strength to withstand the internal and external pressure difference. When installing, the glass is sealed and fixed with the window frame by a sealing rubber strip made of rubber material such as fluororubber, which can not only ensure good sealing effect to prevent material leakage and foreign matter from entering, but also play a buffering role to avoid damage to the glass due to external pressure.

[0145] The position of the observation window on one side of the feeding pipe 31 takes into full consideration of the two factors of facilitating observation by the operator and being able to fully reflect the color situation of the polymer particles. It is usually installed in the middle of the straight section of the feeding pipe 31, and tries to avoid the connection parts of the pipe, support structures and other places that may affect the observation line of sight. In addition, if there are different flow direction changes or areas where material mixing occurs near the feeding pipe 31, observation windows will also be appropriately added to better monitor the color changes of polymer particles in these key links and timely discover potential quality problems.

[0146] The size of the observation window is determined according to the pipe diameter of the feeding pipe 31 and the actual observation requirements. For the feeding pipe 31 with a smaller pipe diameter (such as a pipe diameter less than 200 millimeters), the length and width of the observation window may be about 100-200 millimeters, which can ensure a sufficient field of view to observe the particle condition without weakening the overall strength of the pipe too much. For the feeding pipe 31 with a large pipe diameter (pipe diameter greater than 500 millimeters), the size of the observation window can be appropriately increased, with a length of 300-500 millimeters and a width of 200-300 millimeters to provide a wider observation angle for the operator to more clearly and comprehensively view the color and state of the polymer particles.

[0147] In order to clearly observe the color of the polymer particles in the feeding pipe 31 under various light conditions, especially in the dark production environment, a lighting device is installed around the inner frame of the observation window. The lighting device can be selected as a waterproof, explosion-proof and brightness adjustable LED light belt. The LED light belt is evenly distributed along the inner edge of the window frame. The light emitted by the LED light belt is scattered and homogenized by a special optical lens to ensure that the light can uniformly illuminate the inside of the pipe, avoid the occurrence of shadow or local over-bright or over-dark conditions, and make the color of the polymer particles truly and clearly presented. The lighting device is controlled by an independent power switch and can be connected with the control system of the equipment to automatically turn on or off according to the production time or actual observation needs.

[0148] Although the present application has been illustrated and described with reference to certain preferred embodiments thereof, it should be understood that the above description is a further illustration of the application and should not be construed as limiting the application. Various modifications and alterations can be made to the present application by those skilled in the art, including making a number of simple substitutions or changes in form or details, without departing from the spirit and scope of the present application.

Claims

1. An underwater pelletizer for producing polymer pellets from a molten polymer, characterized in that, The application relates to a polymer particle forming device. The device comprises: a forming conveying assembly, which comprises an extrusion pressurizing module for pressurizing and plasticizing molten polymer into a linear solution; a cutting assembly, which comprises a water tank and a cutter module arranged in the water tank, wherein a constant-temperature water flow is arranged in the water tank to flow in a fixed direction, the linear solution flows into the cutter module in the water tank after being extruded by the extrusion pressurizing module, and the linear solution is cut into polymer particles by the cutter module and flows with the constant-temperature water flow; 2. The underwater pellet cutter of claim 1, wherein, a conveying assembly, which comprises a feeding pipe and a distribution pipe, the bottom of the feeding pipe is provided with an opening, the distribution pipe is communicated with the opening, a distribution switch is arranged at the opening, the polymer particles flow into the distribution pipe from the feeding pipe when the distribution switch is opened, and the polymer particles flow into the next process from the feeding pipe when the distribution switch is closed. The extrusion pressurizing module comprises: a double-screw extruder, polymer melt flows into the double-screw extruder from the previous process, the double-screw extruder heats the polymer melt to a molten state and uniformly mixes the molten polymer; a melt pump, the uniformly mixed molten polymer flows into the melt pump, and the melt pump is used for pressurizing the molten polymer; a screen changer, the pressurized molten polymer flows into the screen changer, and the screen changer is used for filtering the molten polymer; 3. The underwater pellet cutter of claim 2, wherein, a die head, the pressurized molten polymer is extruded from the die head, a die is arranged on the die head, a plurality of through holes for extruding the molten polymer are arranged in an array on the die, and the molten polymer is extruded to form the linear solution through the through holes. The linear solution is extruded into the water tank from the die head and is cooled and formed in the water tank, and the water tank further comprises: a water pump, which comprises a radial nozzle and a tangential nozzle, the radial nozzle is arranged towards the cutter module and is used for flushing the cutter module to prevent the polymer particles from adhering, and the tangential nozzle is used for pushing the water in the water tank to flow in a preset direction to send the polymer particles to the feeding pipe to flow into the next process; 4. The underwater die cutter of claim 3, wherein, a heat exchanger, which is used for keeping the water in the water tank at a constant temperature within a preset temperature threshold. The cutter module comprises: a moving cutter unit, which comprises a moving cutter, the moving cutter is connected with a driving motor through a shaft coupling and is rotated by the driving motor to cut the linear solution into polymer particles, and the radial nozzle is arranged towards the moving cutter; 5. The underwater die cutter of claim 4, wherein, a fixed cutter unit, which comprises a fixed cutter, the fixed cutter is fixedly installed on the opposite side of the moving cutter and forms a shearing gap with the moving cutter to completely cut the linear solution. The cutter module further comprises: an adjusting mechanism, which comprises a cutter shaft and an adjusting component connected with the cutter shaft, the moving cutter is installed on the cutter shaft, and the adjusting component can push the cutter shaft to move along the extension direction of the cutter shaft to adjust the gap between the moving cutter and the fixed cutter; a pressure sensor, which is arranged on the moving cutter and is used for detecting the contact pressure of each blade when cutting.

6. The underwater die cutter of claim 1, wherein, The feeding pipe is provided with an identification unit, which is arranged above the opening and used for identifying the color of the polymer particles on the feeding pipe.

7. The underwater die cutter of claim 1, wherein, The spin-drying module is further included, the flowing polymer particles are driven by the constant-temperature water flow to flow into the spin-drying module, and the spin-drying module is used for drying the polymer particles and then sending the polymer particles into the feeding pipe.

8. The underwater die cutter of claim 7, wherein, The spin-drying module includes a centrifugal dryer, the constant-temperature water flow drives the polymer particles to flow into a rotating drum, the rotating drum rotates to separate the water flow and the water on the polymer particles, and the polymer particles after water separation are sent into the next process by the rotating drum through the feeding pipe.

9. The underwater pellet mill of claim 8, wherein, The vibrating screen is further included, the polymer particles are sent into the vibrating screen by the rotating drum through the feeding pipe, and the vibrating screen vibrates and sorts the polymer particles. The dryer is further included, the polymer particles after screening by the vibrating screen flow into the dryer, the dryer air-dries and dehydrates the polymer particles, and then sends the polymer particles into the feeding pipe.

10. The underwater die cutter of claim 1, wherein, An observation window is arranged on one side of the feeding pipe, transparent glass is installed on the observation window, and the observation window is used for visually checking the color of the polymer particles.

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