• Title/Summary/Keyword: bead radius

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Development of Bioreactors for Hydrogen-Producing Immobilized Photosynthetic Bacteria(I) : Evaluation of lmmobilized CSTR for Hydrogen Productivity and Effectiveness Factor (광합성 박테리아를 이용한 고성능 수소 생산 고정화 생물반응기의 개발(I) 고정화 연속 교반탱크 반응기에서의 수소 생산성 및 효율인자 평가)

  • 선용호;한정우
    • KSBB Journal
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    • v.8 no.3
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    • pp.243-255
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    • 1993
  • In this study, it was observed that hydrogen Productivity varied with stirrer speed, bead radius, input glucose concentration and dilution rate in a continuous stirred tank reactor in which immobilized R. rubrum KS-301 was used as a hydrogen-producing bacterium The mass transfer resistance due to cell immobilization was also studied. In order to estimate an effectiveness factor, Des of glucose was first obtained, which was subsequently represented by the correlation equation between Dos and Xb, As a result external mass transfer resistance could be neglected for stirrer speeds greater than 400rpn With bead radius increasing, the hydrogen productivity and internal effectiveness factor decreased. With input 91ucose concentration increasing, the hydrogen productivity and interval and external effectiveness factor increased. Although an Internal effectiveness factor was not affected, hydrogen productivity Increased with dilution rate increasing. An overall effectiveness factor remained nearly constant for the dilution rates investigate4 but increased with input 91ucose concentration increasing.

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Development of Drawbead Expert Models for Finite Element Analysis of Sheet Metal Forming Processes (Part1:Experiment) (박판성형공정의 유한요소해석을 위한 드로우비드 전문모델 개발(1부: 실험))

  • Lee, Jae-U;Keum, Yeong-Tak
    • Transactions of Materials Processing
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    • v.7 no.1
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    • pp.3-11
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    • 1998
  • During the forming process of sheet metals, the drawbead in the die face controls a restraining force so that the sheet flows into the die cavity with tension. In order to investigate a drawgbead restraining force and a pre-strain just after drawbeads which are essential in the finite element analysis of form-ing processes, the friction test and drawing test are employed. The experiments performed with a cir-cular bead stepped bead double circular bead and circular-and-stepped bead in the various forming conditions and bead sizes show that the restraining force varies linearly with the blank holding force. bead radius blank thickness and friction but the pre-strain nonlinearly does with them.

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A study on the drawing characteristics of circular drawbead by the Finite Element Method (유한요소법에 의한 원형드로오비드의 인출특성에 관한 연구)

  • 신양호
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.6 no.3
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    • pp.26-35
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    • 1997
  • In this study, the drawing characteristics of circular drawbead are examined with the plane strain elastic-plastic FE Method. Both the clamping load and the drawing load investigated by varying the process variables such as drawbead radius, closing depth and friction condition. The effective strain induced by the draw bead is also investigated. In order to verify the results, the computed results are compared with the existing experimental results. It has been found that both the clamping load and drawing loads are related with the geometry of the bead rather than the lubrication conditions.

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An Experimental Study on the Shear Buckling of a Composite Plate with Bead and Hole (비드와 원공을 갖는 복합재 평판의 전단 좌굴 실험에 관한 연구)

  • 임효식;김주언;황정선
    • Journal of the Korea Institute of Military Science and Technology
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    • v.3 no.1
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    • pp.146-154
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    • 2000
  • Buckling behavior was studied for the square plate with bead and hole under shear load. Plates were made to examine the effect of bead and hole to the material, aluminum and composite, the effect of flange angle, bead height and bead radius of curvature. There was little difference between buckling loads obtained by the experiment and Rayleigh-Ritz method to the plate. Buckling load could be increased highly when stress concentration to the hole was dispersed effectively using flange. A well-designed plate using bead and flange showed 3 times as much as stiffness to the plate without bead and flange.

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Degradation of Polyvinyl Alcohol in Dye-Processing Wastewater by Agar-Acrylamide Microbial Immobilization Method (한천-아크릴아마이드 미생물 고정화법에 의한 폐수 중 폴리비닐알콜의 분해)

  • 김재훈;김정목조무환
    • KSBB Journal
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    • v.10 no.3
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    • pp.241-248
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    • 1995
  • For the treatment of poorly biodegradable polyvinyl alcohol(PVA) in dye-processing wastewater, immobilized microbial beads were prepared by uslng agar-acrylamide method. PVA removal efficiency for the synthetic wastewater was 85% at the PVA volume loading rate of $3.1g/\ell$.day. In case of real desizing wastewater, PVA removal efficiency was 81.3% at the PVA volume loading rate of $3.25g/\ell$.day. In observation of cross section of immobilized bead passed 5 months with diameter of 2.4mm, the growth of cell was limited by the resistance of substrate and oxygen transfer for the inners region of more than 48% of bead radius from the surface. It was estimated that 70% of total removed PVA was degraded by the immobilized cells in the continuous immobilized reactor. Substrate utilization rate in the suspended reactor was decreased with increasing dilution rates above 0.083 hr-1, but that in the immobilized reactor was increased with increasing dilution rates up to 0.125hr-1. The substrate removal efficiency of immobilized reactor was much superior to that of suspended reactor with increasing dilution rates. Saturation constant of substrate utilization rate equation, Ks was $6.6 g PVA/\ell$, and maximum specific substrate utilization. k was 0.175g PVA/g cell.hr

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