The development trend of optimization design of screw extruder is analyzed in depth
The development trend of optimization design of screw extruder is analyzed in depth
The plastic net on May 30, 2016, the global network - 】 as polymer processing forming one of the main equipment of screw extruder, get more and more extensive application in polymer processing industry, but also in other industries will get more applications. Sign the working performance of the screw extruder main technical parameters are: screw diameter, screw length to diameter ratio, screw speed range, drag the main screw motor power, machinery, production capacity, the barrel of the heating power and the number of segments, the center of the machine height size and shape, etc., these parameters are measured and choose the main basis of extruder, is designed screw extruder first need to determine the technical parameters. According to the three kinds of polymer in screw extruder physical state change process, as well as to the work requirements of each part of the screw, the screw extruder screw is usually divided into charging, melting and metering section. Because the geometry of the screw is very complicated, it is difficult to establish a mathematical model that can fully reflect the optimal design of the screw extruder. Can even set up an ideal mathematical model for optimal design of screw extruder, due to the complexity of influencing factors, design variables, is also very difficult to solve it, so according to the function of the screw Duan Jianmo and optimize design, conform to the actual requirements. Depth profiling screw extruder optimization design development trend (image) is derived from the network the theory and method for optimizing design of screw extruder at present, the commonly used method for the optimization design of screw extruder are: analytic method and graphical method and computer simulation method. According to the phenomenon of physical model is established, according to the mathematical model is set up physical models, using Pro/E, ANSYS, Polyflow, Matlab software programming optimization design, the input program to computer and by changing the value of optimization calculation is made, through the optimization of computer output result analysis and validation, extruder optimal design parameters are obtained. In addition to the planned optimization goals, the analytical mathematical model depends on the working conditions and theories of the parts. A design scheme can be represented by a number of basic parameters. The independent parameters that need to be selected are called design variables. Because of the extruder screw diameter, length to diameter ratio, thread Angle and screw groove depth is directly related to the screw parameters such as bearing capacity, production capacity, power consumption and extrudate quality, as well as the screw machine processability, etc., so usually choose as design variables. The optimal design features of screw extruder are: design variables; Multi-objective and single-objective optimization design coexist; The multidimensionality and non-linearity of mathematical model; A variety of dimensions coexist in design variables. Screw extruder optimization design of single screw extruder optimization design Tian PuJian from single screw extruder extrusion process and extrusion theory, analysis the screw structure and its geometric parameters affect the performance of screw plasticization, put forward to measure the screw plasticizing performance standards, and the optimization goal, polypropylene (PP)/bamboo powder, for example, optimize the relevant geometric parameters of the screw. The optimization results show that the special screw than ordinary plastic wood-plastics composites with screw in favor of the delivery of the wood plastic composite melt, avoided because wood plastic composite melt viscosity increase and appear a series of problems. The factors that influence the pressure field of the material plasticizing section are: the depth of the gauge, the Angle of the screw, the width of the screw. If it increases the depth of the spiral groove and reduces the Angle of the screw, it can effectively reduce the energy consumption required by the metering section. This is because the larger the spiral depth, the smaller the Angle of the screw, the smaller the resistance of the melt, and the less energy consumed by the metering section. The increase of the spiral width and the increase of energy consumption of the metering section of the feed melt are increasing, but the trend is more gentle. If the spiral width is increased too much, the power consumption of the screw will increase, and there will be a danger of local overheating, which should be controlled in a suitable range. Using Pro/E analysis software, the optimal extruder screw factor was finally determined to achieve the aim of improving production efficiency. Zhi-gang huang based on orthogonal experiment method combined with Matlab simulation method of single screw extruder of a numerical simulation of the solid conveying section is obtained by various optimization analysis was carried out on the target, the optimal results, draw a solid conveying section of single screw geometry parameters on the solid conveying rate and the influence of the solid conveying efficiency, and the optimal parameter combination of screw. Optimization process: firstly, the screw rod of single screw extruder can be optimized quickly and efficiently by combining the simulation and orthogonal test method. Second, due to the spiral groove width of solid conveying rate and solid conveying efficiency is larger, the influence of pitch on the effects of solid conveying rate is the largest, so using Matlab software to optimize the structure of the single screw extruder, to ensure that the above two factors impact on the material in the extrusion process control in a reasonable range. The results show that the design results are not only high reliability, but also shorten the design cycle of single screw and reduce the r&d cost. A and Xue Ping on new type of screw extruder was established in line with the actual size and shape of the finite element model, using ANSYS finite element software on the stress analysis and comparing with the traditional method, proved reasonably using finite element method (fem) simulation, can optimize the extrusion process parameters and structure design of adjustment, the best way to get reasonable. In this paper, the optimal design of screw extruder for single screw extruder is discussed. The minimum energy consumption per unit of production as the optimization goal, the establishment of simplified extruder feeding section of screw, the mathematical model of optimal design, constrained coordinate rotation method was applied to solve, the spiral groove width, screw groove depth and thread Angle optimal values are located in or close to the optimal value range of the proposed in the literature. The optimal design of the single screw extruder is also discussed. Study mentioned in the spiral groove depth, spiral rib width and thread Angle is directly related to plastic extruder production capacity, quality and energy consumption, and with the geometric parameters as design variables, the minimum energy consumption per unit of production as the optimization goal, and has set up a simplified extruder melting section of the screw, the mathematical model of optimization design. The constrained composite method is applied to solve the problem. In this way, the optimal value of the spiral groove, the width of the screw and the Angle of screw Angle is obtained, and the melting section of the screw is optimized. In addition, the optimal design of the extruder screw gauge is also discussed. Using the basic equation of viscous fluid dynamics, the flow of polymer materials in the spiral groove was analyzed. Based on the minimum energy consumption of the unit, a simplified mathematical model of the optimal design of the metering section of extruder is established, and the stochastic direction method is applied to solve the problem. The results show that the depth of the spiral groove, the width of the screw, the top of the thread and the gap of the machine barrel and the Angle of the screw thread are all located in or close to the optimal range proposed in the literature. Goldkorn using three-dimensional modeling software UG to triangle groove barrier mixing element on the structure of the different 3 d modeling, and then mixing element using the finite element analysis software Polyflow flow field in the three dimensional isothermal numerical simulation, and in accordance with the pressure, velocity of flow field, temperature, shear rate and depolymerization of hybrid index and average power and other parameters on the flow field characteristics and mixing effect is analyzed. Finally, the results of numerical simulation were verified by the experiment of LLDPE (LLDPE)/CaCO3. Through numerical simulation and experimental analysis, the following conclusions are obtained: (1) the shape of the triangle groove is the main factor affecting the mixing effect of the mixing component. Triangle groove in the research of four kinds of barriers in mixed element, an isosceles triangle groove reverse barrier mixing elements of peak pressure, shear flow field edges on both sides of the maximum differential pressure and high shear zone proportion mixing elements are higher than other structure and flow field temperature rise higher, shearing edge broken and abrasive action of material, the strongest blend of CaCO3 particles, the average particle size of the minimum material tensile mechanical properties of the best; (2) the cutting edge width and the radial clearance of shear edges also have important influence on the mixing effect of the mixing element flow field. The shearing edge width is 5 mm, shearing edge triangle groove radial clearance of 2 mm barrier mixing elements of material shearing action and dispersive mixing effect is best, blend of CaCO3 particles, the average particle size of the minimum material tensile mechanical properties of the best; (3) the average particle size of CaCO3 particles in the blends can be effectively reduced by increasing the rotation speed of the screw, and the overall mixing effect of mixing components can be improved. Double screw extrusion machine optimization design Li Jinwei to solve SJ - 150 double screw extrusion machine machine barrel wear caused by the thermal deformation problem, puts forward a new design scheme, structure and use of Pro/E and ANSYSWorkbench build collaborative simulation platform, the new scheme of barrel structure, the optimization analysis, determines the optimum location, port barrel flow aperture, and the optimal value of wall thickness. By comparing with the original scheme, the following results are obtained: the overall thermal deformation of the machine cylinder of the improved scheme is reduced by 15.4%, which effectively reduces the wear between the cylinder and the screw. Wang li to support the development of high performance synthetic double screw extruder, in the comparison of several small gear transmission design, on the basis of considering the same double screw two output axial-radial severely restricted space and meet the requirements of the gear contact strength, fatigue strength, the minimum centre distance as the optimization goal, established a three-axis torque distribution to two pairs of gear transmission system optimization mathematical model, and the programming of the mixed penalty function method is used for optimization calculation. In optimization calculation, with 35 synthetic Φ rotating twin screw extruder speed reducer as an example to conduct a comprehensive elaboration, the results show that the distribution of the gear optimization design model is established for small synthetic twin-screw extruder to slow down the development of distribution box to provide optimum design parameters. He liang conical twin-screw extruder is introduced the basic parameters of the screw and the functional parameters of design basis, and aims at SJSZ conical twin screw extruder in the optimization design was carried out on the screw, from the basic parameters of the screw, the functional parameters and analysis of end face curve correction, etc, each parameter is determined by using three dimensional modelling software optimized conical twin-screw structure are obtained. There are usually three methods for correcting screw gaps: first, reduce the theoretical center distance; Secondly, the theoretical axial curve is shifted along the axial and radial direction, and the new thread curve is obtained. Finally, the adjustment of the points along the normal line of the screw surface is shifted along the normal distance, eliminating the shortcomings of the gap law of the axial section, and establishing the correction equation. Liu yan layer reference double screw extrusion machine drive system of some factory as an example, according to the relevant data transmission system and the known conditions, analyze the advantages and disadvantages, and finally optimize the design, so as to achieve a higher requirements. The simplified diagram of the extruder reducer is shown in figure 1. Bring figure 1 twin screw extruder reducer drive system structure diagram, the author first of all, double screw extrusion machine drive system are analyzed, and mastered the arrangement of gear box and various transmission scheme, with the known transmission system has carried on the contrast analysis, conclude its advantages and disadvantages; Then the gear in the transmission system was optimized by Matlab software and optimization toolbox. In the optimization process, mathematical models are established, including the establishment of objective functions, selection of design variables and constraint functions. Then the gears are optimized by Matlab programming. Finally, the gear of the two screw drive shaft and auxiliary shaft was designed. The optimization result shows that the output shaft speed is 43% higher than before optimization, thus improving the productivity of the double screw extruder. Compared with the initial parameters and optimized parameters, the modulus and the tooth number of the gears are reduced, so that the volume and quality of the transmission system are reduced, and the manufacturing cost is saved. Xu Kuo twin-screw extruder gearbox as the research object, by Pro/E, ANSYS as the main application software, creating transmission case in Pro/E components and complete the assembly of the whole body, in the ANSYS finite element analysis was carried out on the box body; Based on the results of finite element analysis, the structure optimization analysis of the driving box of twin screw extruder is carried out. The specific research work and achievements include: to complete the load analysis of the transmission box and establish the three-dimensional model of the transmission box; The static finite element analysis of the gear pair and the box body of the transmission box is carried out. Modal finite element analysis of transmission box and gear assembly is carried out. The structure optimization of the drive box of twin screw extruder was analyzed. Optimization process, according to the motor speed and rated power transmission in the stress analysis of gear shaft in the driving force of the gear mesh point and bearing reaction force of each gear shaft support in using 3 d design software Pro/E3.0 modeling for the transmission case main parts; According to the assembly principle, the assembly of the transmission box is completed, the parts are inspected, the parts are not interfered, and the assembly works well. In the ANSYSworkbench interface, the contact analysis of gear pairs was obtained, and the static contact analysis results of two teeth and three teeth meshing were obtained. The validity of finite element analysis is verified by comparing with the calculation value of the traditional contact stress formula. By using ANSYS software of gear box housing and gear assembly modal finite element analysis, through the modal analysis for gearbox housing and gear assembly of inherent frequency and vibration mode of the figure, compared with the excitation frequency of transmission case, verify the safety of casing, and the rationality of the gear assembly structure arrangements. Conclusion: use of parameterized modeling software Pro/E and general finite element software ANSYS to build collaborative simulation platform, analysis of the basic parameters of screw extruder and screw structure, parametric modeling of screw extruder, it is concluded that the optimal design scheme. Compared with the experience design method, the design method is shorter and less cost, and the determination of important parameters is more reliable, which can be used as reference for similar screw design.
