• 제목/요약/키워드: Centrifugal fluidized bed

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경유차 배기가스 저감용 원심유동층 촉매반응장치의 유동특성에 관한 연구 (A study on the fluidization of centrifugal fluidized bed for reduction of exhaust gas from diesel powered vehicle)

  • 이관석;금성민
    • 한국산학기술학회논문지
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    • 제17권2호
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    • pp.209-213
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    • 2016
  • 경유자동차의 질소산화물을 저감하기위한 원심유동층장치를 개발하기 위해, 가스분산판 내경 184mm, 폭 50mm의 원심유동층장치에서 평균입자직경 $26{\mu}m$, $32{\mu}m$의 Cu-ZSM-5 제오라이트 촉매를 유동입자로 사용하여 원심유동층의 유동특성을 조사한 결과, 원심유동층내의 기포직경은 거의 0.3~3.0mm의 작은 범위이며, 기포의 상승속도는 기포직경 및 가스속도와 상관없이 0.0~0.4m/s 정도이다. 또한 원심유동층에서 사용가능한 평균입자 직경은 $60{\mu}m$이며, 층내에서 기체와 고체의 접촉은 양호한 것으로 조사되었다.

원심유동층에서 Al2O3의 기포 거동에 관한 연구 (Bubble Behavior in Centrifugal Fluidized Bed of Fine Particles)

  • 이관석;금성민
    • 한국산학기술학회논문지
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    • 제10권7호
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    • pp.1446-1452
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    • 2009
  • 직경 340mm, 높이 195mm의 원심유동층에서 10.5${\mu}m$와 21.5${\mu}m$의 평균직경을 갖는 $Al_2O_3$를 유동물질로 하여 400, 600, 800, 1000rpm으로 기포의 거동을 규명하고자 2중사진 촬영에 의해 유동가시화현상을 실험하였다. 실험결과, 본 실험 범위에서 원심유동층에서 기포의 거동은 회전수에 영향을 받는 것을 알 수 있었으며, 회전수가 증가함에 따라 기포가 발생하기 시작하는 속도는 증가하였으나 기포의 직경은 감소하는 것을 알 수 있었고 기포의 크기는 상대적으로 작게 나타났다.

Various Types and Manufacturing Techniques of Nano and Micro Capsules for Nanofood

  • Kim, Dong-Myong
    • Journal of Dairy Science and Biotechnology
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    • 제24권1호
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    • pp.53-63
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    • 2006
  • Nano and micro capsulation (NM capsulation) involve the incorporation for nanofood materials, enzymes, cells or other materials in small capsules. Since Kim D. M. (2001) showed that a new type of food called firstly the name of nanofood, which means nanotechnology for food, and the encapsulated materials can be protected from moisture, heat or other extreme conditions, thus enhancing their stability and maintaining viability applications for this nanofood technique have increased in the food. NM capsules for nanofood is also utilized to mask odours or tastes. Various techniques are employed to form the capsules, including spray drying, spray chilling or spray cooling, extrusion coating, fluidized bed coating, liposome entrapment, coacervation, inclusion complexation, centrifugal extrusion and rotational suspension separation. Each of these techniques is discussed in this review. A wide variety of nanofood is NM capsulated - flavouring agents, acids, bases, artificial sweeteners, colourants, preservatives, leavening agents, antioxidants, agents with undesirable flavours, odours and nutrients, among others. The use of NM capsulation for sweeteners such as aspartame and flavors in chewing gum is well known. Fats, starches, dextrins, alginates, protein and lipid materials can be employed as encapsulating materials. Various methods exist to release the ingredients from the capsules. Release can be site-specific, stage-specific or signaled by changes in pH, temperature, irradiation or osmotic shock. NM capsulation for the nanofood, the most common method is by solvent-activated release. The addition of water to dry beverages or cake mixes is an example. Liposomes have been applied in cheese-making, and its use in the preparation of nanofood emulsions such as spreads, margarine and mayonnaise is a developing area. Most recent developments include the NM capsulation for nanofood in the areas of controlled release, carrier materials, preparation methods and sweetener immobilization. New markets are being developed and current research is underway to reduce the high production costs and lack of food-grade materials.

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