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The Effect of Coal Particle Arrangement and Size Difference on Combustion Characteristics (미분탄 입자의 크기 차이와 배열이 연소특성에 미치는 영향)

  • Kim, Ki-Duck;Kim, Ho-Young;Cho, Chong-Pyo;Yoon, Suk-Goo
    • 한국연소학회:학술대회논문집
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    • 2007.05a
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    • pp.47-53
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    • 2007
  • The laminar combustion characteristics of interacting coal particles in a convective flow are numerically investigated at particle arrangement and size difference. The numerical simulations, which use the two-step global reaction model to account for the surrounding gas effect, show the detailed interaction among the inter-space particles, undergoing devolatilization and subsequent char burning. Several parametric studies, which include the effect of the gas temperature (1700 K), high pressure(10 atm) and variation in geometrical arrangement of the particle diameter on the volatile release rate and the char combustion rate, have been carried out. The comparison indicates that the shift to the multiple particle arrangement resulted in the substantial change of the combustion characteristics and that the volatile release rate of the interacting coal particles exhibits a strong dependency on the particle spacing and size difference.

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Synthesis and Characterization of Phosphorus Polyurethanes Using Phosphorus Polyols (인계 폴리올을 이용한 난연성 폴리우레탄의 합성 및 특성 분석)

  • Kim, Taeyoon;Kim, Yong Gap;Lim, Chung-Sun;Seo, Bongkuk;Lee, Wonjoo
    • Journal of Adhesion and Interface
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    • v.20 no.2
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    • pp.61-65
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    • 2019
  • In this study, phosphorus polyols, having a molecular weight of 880 to 1,560 g/mol, were synthesized by reacting phenylphosphonic dichloride (PPDC), allylphosphonic dichloride (APDC), and ethylene glycol (EG) in solvent, to enhance flame retardance of polyurethane. Phosphorus polyurethanes were polymerized using the synthesized phosphorus polyols, polycarbonate diol (PCD), and 4,4'-diphenylmethane diisocyanate (MDI) by a melt polymerization method. As increasing phosphorus contents of the phosphorus polyurethanes, we observed that the remaining char amount increased. This tendency was also confirmed in the following UL-94V test. We found that when the synthesized phosphorus polyols were applied, the resulting phosphorus polyurethanes show UL-94V0 grade at above 0.5 wt% phosphorus contents.