• Applied Chemistry for Engineering
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• v.21 no.1
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• pp.111-114
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• 2010

In the attrition reactor for the American Society for Testing and Materials (ASTM) D5757-95, the attrition characteristics of catalysts for water gas shift reaction were investigated. The effects of attrition characteristics of low temperature shift catalysts (LTS) and high temperature shift catalysts (HTS) on fluidization phenomena and average particle size were investigated and compared with the attrition characteristics of sand particles. The particle size of catalysts was decreased and particle size distribution in attrition tube was changed due to the effect of gas injection. About 40~50 wt% samples of original catalyst particles were entrained and lost. The amount of fly ash of LTS catalyst was less than that of HTS. Also, the weight of entrained particles which had original particle size of $212{\sim}300{\mu}m$ was lower than any other cases.

• Korean Chemical Engineering Research
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• v.55 no.5
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• pp.638-645
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• 2017

A model for predicting the transport velocity was proposed using the correlation of the particle entrainment rate in the gas fluidized bed. The emptying time method was simulated using correlations of Choi et al. and Li and Kato. In order to exclude the influence of the unit of the gas velocity, the dimensionless velocity obtained by dividing the gas velocity by the terminal velocity was used as the value of the x-axis. The inverse of the particle entrainment rate was used as the value of the y-axis. When increasing the gas velocity, the non-dimensional velocity, at which the decreasing slope of the y-value is 0.398 [$m^2s/kg$] in absolute value, was considered as the transport velocity. The transport velocity predicted by the model was in good agreement even at high temperature and high pressure.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 1998.10a
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• pp.73-75
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• 1998

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.11
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• pp.3274-3279
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• 2009

The elutriation characteristics of particle size distribution were investigated in a gas-solid fluidized bed. Experiments were carried out with the mulit-sized particles of Gaussian distributions. The elutriation rate constant obtained from the experiment was correlated with the standard deviation of particle size and the dimensionless group of the velocity ratio. The standard deviation of pressure fluctuation, mean pressure, major frequency and power spectrum density function were calculated by pressure fluctuation properties. Size distribution of elutriated particles and pressure fluctuations were measured for the particle size distribution of particle system depended largrly on the size distribution. Characteristics of fluidization and elutriation were greatly influenced by the particle size distribution and these characteristics could be interpreted with pressure fluctuation properties.

• Journal of the Mineralogical Society of Korea
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• v.28 no.2
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• pp.147-163
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• 2015

Chemical and mineralogical properties of coal ash samples from the nine thermal power plants of Korea were investigated to acquire basic data for estimating the potential of rare metal recovery. Chemical compositions of coal ash were consistent with those of average shale and foreign coal ashes. However, there were small differences between the metal contents of domestic anthracitic and imported bituminous coal ashes. Unburned coal particles were much abundant in the ash of domestic anthracitic coal. Chalcophile elements were relatively enriched in the fly ash compared to bottom ash. Silicate glass was the major component of coal ash with minor minerals such as quartz, illite (muscovite), mullite, magnetite, lime, and anhydrite. Al and Si were the major components of the glass with varying contents of Ca, Fe, K, and Mg. Glass occurred in a form of porous sphere and irregular pumace-like grain often fused with iron oxide spheres or other glass grains. Iron oxide spheres were fine intergrowth of fast-grown iron oxide crystals in the matrix of silicate glass. Chemical, microstructural, and mineralogical properties would guide successful rare metal recovery from coal ash.

• Textile Coloration and Finishing
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• v.7 no.2
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• pp.92-93
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• 1995

1970년도 후반까지만 하더라도 염료생산은 선진국형 산업으로만 생각하여 왔으나 인건비 상승, 환경처리비부담, 운성비 등의 부담으로 선직국의 염료생산공장들은 앞다투어 생산기지를 후진국으로 신설 또는 이전을 하게 되었다. 한편 생산량도 증가되어 수요에 비하여 공급과다로 지나친 판매경쟁이 일어나고 채산성도 나빠진 것이 현실이다. 이러한 나라들 중에는 제조기술의 미흡, 원가절감, 품질관리의 미숙 등으로 lot별 농도차이, 용해성불량, 염료중에서의 재응집, 飛散등의 문제로 염색공장에서 애로를 겪는 경우가 자주 발생하고 있다. 특히 염료의 비산 문제는 칭량원의 보건상 나쁜 영향을 미치게 되고 염색현장까지 염료입자가 날아가 피염물에 오염을 일으키기도 한다. 이러한 문제점을 해결하기 위하여서는 다각적으로 관리에 철저를 기하지 않으면 안된다.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.05b
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• pp.223-224
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• 2003

포장도로에서 발생되는 미세먼지는 주로 자동차의 운행에 의한 직접 배출되는 입자와 도로 표면에서 비산되는 토양입자 그리고 타이어나 브레이크 패드의 마모에 의한 고무 및 석면 둥 다양한 배출원에 의해 발생되는데, 도로 주변의 배출원에 의해 많은 영향을 받을 것으로 판단된다. (최금찬등, 1996) 특히 인천에는 많은 비산먼지 배출원이 산재하여 있어, 이 들 배출원들의 영향이 여타 대도시보다 클 것으로 판단된다. 따라서, 본 연구에서는 인구와 교통량이 많고 공업활동이 활발한 인천지역의 주요 포장도로(H-ADT: High Average Daily Traffic, 5,000대/일 이상인 도로)에서 채취한 silt를 주거지역, 공업지역, 상업지역, 기타지역별로 채취하여 화학적 성분분석을 통해 지역별 특성을 조사하여, 각 지역 별 포장도로에서의 silt의 기원이 무엇인지를 추정하는 기초자료를 구축하고자하였다. (중략)

• Proceedings of the SAREK Conference
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• 2007.06a
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• pp.133-133
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• 2007

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1999.11a
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• pp.31-34
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• 1999

기-고체간의 접촉효율이 높고, 층 내 전체에 걸쳐서 균일한 기-고의 접촉을 갖는 등 많은 장점이 있어 석탄연소로, 촉매반응기와 같은 여러 기-고 반응기에 적용이 확대되고 있는 순환유동층은 높은 유속에서 조업되므로 상승관내 고체입자들은 즉시 비산하게 된다. 따라서, 원활한 반응에 필요한 상승관내 적절한 고체체류량 유지를 위해 고체입자들 대부분은 싸이클론에서 포집 되어 고체재순환부에 의하여 상승관내로 재주입 된다.(중략)

• Journal of Korean Society of Environmental Engineers
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• v.35 no.8
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• pp.547-553
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• 2013

This paper investigates the effect of coal-fired fly ash on dry $CO_2$ sorbents as the supports and additives. For this purpose, various kinds of dry sorbent were manufactured by mixing fly-ash, the primary $CO_2$ absorption components (NaOH and CaO) and water with their different combination. Thereafter, their $CO_2$ absorption performance and the property were analyzed. As a result, variation of absorption efficiency and temperature as well as $CO_2$ desorption of the sorbents are confirmed, which may be primarily ascribed to fly-ash addition to the sorbents. Particularly, fly-ash effect is strongly measured in the sorbent manufactured by mixing all four components (named WNCF sorbents). Absorption efficiency of WNCF sorbents at $550^{\circ}C$ is 35.6% higher than that of flyash free sorbent and desorption is solely observed in WNCF sorbents. Fly-ash in WNCF sorbents leads to increase the dispersity of $CO_2$ absorption components and decrease their particle size in the sorbents. In addition, fly-ash is used as the supports and pozzolanic reaction is hindered by NaOH in WNCF sorbent. Furthermore, $CO_2$ desorption from the sorbents may be due to fly-ash. The interaction between fly-ash and $CO_2$ absorption components substantially attenuate the strength between captured $CO_2$ in CaO and NaOH.