• Title, Summary, Keyword: Vertical Roller Mill

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A Study on on Failure Analysis of Table Liner for Roller Mill (롤러 분쇄기용 테이블 라이너의 파손 해석에 관한 연구)

  • Lee, Dong-Woo;Hong, Soon-Hyeok;Lee, Kyoung-Young;Cho, Seok-Swoo;Joo, Won-Sik
    • Proceedings of the KSME Conference
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    • pp.163-169
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    • 2003
  • The vertical roller mill is the important machine grinding and mixing various crude materials in the manufacturing process of portland cement. Table liner is one of grinding elements of vertical roller mill and is subjected to the cyclic bending stress by rollers load and the centrifugal force by rotation of table. It demands $4{\times}10^7$ cycle but has $4{\times}10^6{\sim}8{\times}10^6$ cycle. It fractures at the edge of grinding path of outside roller. The repair expense for it amounts to 30% of total maintenance of vertical roller mill. Therefore, this study shows the fracture mechanism of table liner for vertical roller mill using HDM and fatigue analysis

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A Study on the Safety Estimation of Table Liner for Vertical Roller Mill Using HDM (구멍뚫기법을 이용한 수직형 롤러 분쇄기용 테이블 라이너의 안전성 평가에 관한 연구)

  • Lee Dong Woo;Hong Soon Hyeok;Cho Seok Swoo;Joo Won Sik
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.28 no.8
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    • pp.1221-1228
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    • 2004
  • The vertical roller mill is the important machine grinding and mixing various crude materials in the manufacturing process of portland cement. Table liner is one of grinding elements of vertical roller mill and is subjected to the cyclic bending stress by rollers load and the centrifugal force by rotation of table. It demands $4{\times}10^7$ cycle but has $4{\times}10^6{\sim}8{\times}10^6$ cycle. It fractures at the edge of grinding path of outside roller. The repair expense for it amounts to $30\%$ of total maintenance of vertical roller mill. Therefore, this study shows the fracture mechanism of table liner for vertical roller mill using HDM and fatigue analysis and makes the estimation for safety of vertical roller mill.

A Study on the Prediction of Failure Stress for Table Liner under Fatigue Load (피로하중을 받는 테이블 라이너의 파손응력예측에 관한 연구)

  • 이동우;주원식
    • Journal of the Korean Society for Precision Engineering
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    • v.21 no.8
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    • pp.97-105
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    • 2004
  • The vertical roller mill is the important machine grinding and mixing various crude materials in the manufacturing process of portland cement. Table liner is one of grinding elements of vertical roller mill and is subjected to the cyclic bending stress by rollers and the centrifugal force by rotation of table. It demands $4{\times}10^7$ expense of life but has $4{\times}10^6~-8{\times}10^6$ cycle. It fractures at the edge of grinding path of outside roller The repair expense fur it amounts to 30% of total maintenance of vertical roller mill. Therefore, this study shows the fracture mechanism of table liner of vertical roller mill using HDM and fatigue analysis

A Study on Optimal Design for Vertical Roller Mill using DOE and Neural Network (실험계획법과 신경망을 이용한 수직형 롤러 분쇄기의 최적설계에 관한 연구)

  • Lee, Dong-Woo;Lee, Soo-Jin;Hong, Soon-Hyeok;Cho, Seok-Swoo;Joo, Won-Sik
    • Proceedings of the KSME Conference
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    • pp.1130-1135
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    • 2004
  • The vertical roller mill is the important machine grinding and mixing various crude materials in the manufacturing process of portland cement. Vertical roller mill is subjected to the cyclic bending stress by rollers load. It demands $4{\times}10^7$ cycle but has $4{\times}10^6{\sim}8{\times}10^6$ cycle. It fractures at the edge of grinding path of outside roller. The repair expense for it amounts to 30% of total maintenance. Therefore, this study shows optimal design for vertical roller mill using DOE and neural network.

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Optimization of Vertical Roller Mill by Using Artificial Neural Networks (신경회로망을 이용한 수직형 롤러 분쇄기의 최적설계)

  • Lee, Dong-Woo;Cho, Seok-Swoo
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.34 no.7
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    • pp.813-820
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    • 2010
  • The vertical roller mill is important for machine grinding and mixing various crude materials in the process of producing Portland cement. A vertical roller mill is subjected to cyclic bending stress because of the roller load. Because of the cyclic bending stress, only $4{\times}10^6-8{\times}10^6$ cycles are achieved instead of $4{\times}10^7$ cycles. The stress also causes fractures at the edge of grinding path of the outer roller. The expenses incurred in repairing the grinding path amounts to 30% of the total maintenance cost. Therefore, it is desirable to redesign the vertical roller mill in order to reduce the expenses incurred in repairing the roller. In this study, artificial neural networks (ANNs) were applied in order to solve the multiobjective optimization problem for vertical roller mills by using the function approximation ability of ANNs. To learn and generalize ANNs, the maximum and minimum stresses were estimated from the results of the finite-element analysis of a vertical roller mill. Thus, ANNs could be applied to solve the multiobjective optimization problem.

An Experimental Investigation of Bending Fatigue Strength in Table Liner for Cement Mill (시멘트 분쇄기용 테이블 라이너의 굽힘 피로강도의 실험적 조사)

  • Baek, Seok-Heum;Lee, Kyung-Young;Cho, Seok-Swoo;Jang, Deuk-Yul;Joo, Won-Sik
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.31 no.12
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    • pp.1214-1220
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    • 2007
  • The vertical roller mill, which performs the grinding and partly blending of raw material, is the one of the important machine to produce ordinary portland cement. It has been reported that an unexpected fatigue failure occurred in a table liner in the course of grinding portland cement. The life of table liner is estimated to $4{\times}10^7$ cycles in the design stage, but at the field, when its operating time reaches to $2{\times}10^6{\sim}8{\times}10^6$ cycles, the fracture of table liner begins to be found. The fracture of table liner is initiated from the outside edge of grinding path contacting with the grinding roller. Its maintenance normally take 30 % of the total maintenance costs of the roller mill. Therefore, this study shows the clarification of the reasons occurring the fatal destruction of the table liner by fatigue fracture analysis utilizing fracture mechanics and by the finite element method. And, the results from Goodman diagram illustrate relationship of including information on the transition between tensile and bending fatigue strength in the fatigue characterization of table liner.

A Study on Topology Optimization of Table Liner for Vertical Roller Mill using Homogenization Method (균질화법을 이용한 수직형 롤러 분쇄기용 테이블 라이너의 위상최적설계에 관한 연구)

  • 이동우;홍순혁;조석수;이선봉;주원식
    • Journal of the Korean Society for Precision Engineering
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    • v.20 no.6
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    • pp.113-122
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    • 2003
  • Topology optimization is begun with layout optimization that is attributed to Rozvany and Prager of the 1960's. They claimed that structure was transformed into truss connecting all the nodes of finite element and optimized by control of its sectional modulus. But, this method is partial topology optimization. General layout optimal design appliable to continum structure was proposed by Bendsoe and Kikuchi in 1988. Topology optimization expresses material stiffness of structure into function of arbitrary variable. If this variable is 1, material exists but if this variable is 0, material doesn't exist. Therefore, topology optimization searches the distribution function of material stiffness for structure. There are a few researchs for simple engineering problem such as topology optimization of square plane structure or truss structure. So, This study applied to topology optimization of table liner for vertical roller mill that is the largest scale in the world. After table liner decreased by 20% of original weight, the structure analysis for first optimized model was performed.

Study on Failure in Outer Ring of Work Roll Bearing in Hot Rod Rolling Mill (열간 선재 압연기에서 작업롤 베어링의 외측링 파손에 관한 연구)

  • Byon, Sang-Min
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.16 no.4
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    • pp.38-45
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    • 2017
  • A finite element analysis-based approach which investigates the causes of the breakdown in the outer ring of the choke at hot rod rolling mill is presented. Two-dimensional drawings of the whole vertical-type mill stand are transformed into three-dimensional CAD models. Non-linear elasto-plastic deformation analysis of material at the roll gap is performed for computing roll force and torque of the work roll. Then, the reaction forces of the bearing rings together with a set of roller bearings that support the work roll are obtained by means of rigid body motion analysis. Finally, stress behaviors in the bearing rings together with a set of roller bearings that support the work roll are investigated by linear elastic analysis. Results reveal that stress at the contact area between the outer ring and roller bearing is extraordinary high when an internal gap between an external surface of the outer ring and the internal surface of the chock due to wear of the inside of the chock occurs.

Multi-objective Optimization in Discrete Design Space using the Design of Experiment and the Mathematical Programming (실험계획법과 수리적방법을 이용한 이산설계 공간에서의 다목적 최적설계)

  • Lee, Dong-Woo;Baek, Seok-Heum;Lee, Kyoung-Young;Cho, Seok-Swoo;Joo, Won-Sik
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.10
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    • pp.2150-2158
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    • 2002
  • A recent research and development has the requirement for the optimization to shorten design time of modified or new product model and to obtain more precise engineering solution. General optimization problem must consider many conflicted objective functions simultaneously. Multi-objective optimization treats the multiple objective functions and constraints with design change. But, real engineering problem doesn't describe accurate constraint and objective function owing to the limit of representation. Therefore this study applies variance analysis on the basis of structure analysis and DOE to the vertical roller mill fur portland cement and proposed statistical design model to evaluate the effect of structural modification with design change by performing practical multi-objective optimization considering mass, stress and deflection.