• Title/Summary/Keyword: Ceramic mat

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Reaction Behavior of Ceramic Mat with Lithium Salt for the Electrolyte Separators of Thermal Batteries (전해질 분리판용 세라믹 부직포와 리튬염간의 반응성)

  • Cho, Kwang-Youn;Riu, Doh-Hyung;Shin, Dong-Geun;Lim, Kyoung-Hoon;Jin, Eun-Ju;Kim, Hyoun-Ee;Ha, Sang-Hyeon;Choi, Jong-Hwa
    • Journal of the Korean Ceramic Society
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    • v.46 no.6
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    • pp.587-591
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    • 2009
  • Lithium salt have been used mainly as electrolyte of thermal battery for electricity storage. Recently, The 3phase lithium salt(LiCl-LiF-LiBr) is tried to use as electrolyte of thermal battery for high electric power. It is reported that LiCl-LiF-LiBr salt have high ion mobility due to its high lithium ion concentration. Solid lithium salt is melt to liquid state at above $500{^{\circ}C}$. The lithium ion is easily reacted with support materials. Because the melted lithium ion has small ion size and high ion mobility. For the increasing mechanical strength of electrolyte pellet, the research was started to apply ceramic filter to support of electrolyte. In this study, authors used SiOC web and glass fiber filter as ceramic mat for support of electrolyte and impregnated LiCl-LiF-LiBr salt into ceramic mat at above $500{^{\circ}C}$. The fabricated electrolyte using ceramic mat was washed with distilled water for removing lithium salt on ceramic mat. The washed ceramic mat was observed for lithium ion reaction behavior with XRD, SEM-EDS and so on.

A Study on the Improved Design for Automotive Catalytic Converter (자동차용 촉매장치구조의 설계개선에 관한 연구)

  • Park, Y.C.
    • Transactions of the Korean Society of Automotive Engineers
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    • v.3 no.5
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    • pp.135-142
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    • 1995
  • This paper presents the effect of the component performance for mat supported monolithic cordierite ceramic underflow catalytic converters to meet the new stringent durability requirements of the world's. These objectives are met by a conceptional system approach of mat mounting material with stainless steel can(shall), and heatshield(cover), which are related to the mat erosion, a main failure pattern of the mat supported monolithic ceramic catalytic converters. In this paper we study the individual component behavior of mat erosion problem, After studying, we obtain the characterics of the component performance for automotive catalytic converters and the overall understanding of design considerations in catalytic converters.

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Heating Behavior of Silicon Carbide Fiber Mat under Microwave

  • Khishigbayar, Khos-Erdene;Seo, Jung-Min;Cho, Kwang-Youn
    • Journal of the Korean Ceramic Society
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    • v.53 no.6
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    • pp.707-711
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    • 2016
  • A small diameter of SiC fiber mat can produce much higher heat under microwave irradiation than the other types of SiC materials. Fabrication of high strength SiC fiber consists of iodine vapor curing on polycarbosilane precursor and heat treatment process. The curing stage of polycarbosilane fiber was maintained at $150-200^{\circ}C$ in a vacuum condition under the iodine vapor to fabricate a high thermal radiation SiC fiber. The structure and morphology of the fibers were characterized by Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TG) and scanning electron microscopy (SEM). In this study, the thermal properties of SiC fiber mats under microwave have been analyzed with an IR thermal camera and its image analyzer. The prepared SiC fiber mats radiated high temperature with extremely high heating rate up to $1100^{\circ}C$ in 30 seconds. The fabricated SiC fiber mats were not oxidized after the heat radiation process under the microwave irradiation.

An Experimental Study on Combustion Characteristics of Radiant Burner (복사 버너의 연소특성에 관한 실험적 연구)

  • Wie, Jae-Hyug;Lee, Dae-Rae;Kim, Young-Soo;Jeon, Chung-Hwan
    • 한국연소학회:학술대회논문집
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    • 2006.04a
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    • pp.19-25
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    • 2006
  • Energy efficient and low pollution combustion systems the use gaseous fuels have been in great demand in recent year. Radiant burner in many different forms are emerging as very desirable combustion systems for same reason. Porous radiant burners are used in drying, preheating and curing, and in other type of materials processing and manufacturing processes. However, little knowledge is available about the operating characteristics and the structure of flames in porous ceramic fiber radiant burners. The objective of the present work is to investigate the global performance characteristics of the ceramic fiber burner. A detailed study which includes the spectral intensity, gas temperature, radiation efficiency and global pollutant emissions. Another objective is to study the flame structure of the ceramic fiber burner by measuring the local gas temperature. The results indicate that ceramic fiber burner do offer a 19-44% gain in radiant efficiency. The ceramic fiber burner exhibit significant spectral intensity peaks in the band at $2.0-2.5{\mu}m$. The local temperature distribution inside the mat and near the mat surface as a function of the equivalence ratio can be reasonably interpreted by the relation of the heat balance in the mat and movement of the reaction zone. Nox emission from ceramic fiber burner is less than 25ppm throughout the operating range.

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Heat-Generating Behavior of SiC Fiber Mat Composites Embedded with Ceramic Powder for Heat Conservation

  • Joo, Young Jun;Cho, Kwang Youn
    • Journal of the Korean Ceramic Society
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    • v.56 no.6
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    • pp.583-588
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    • 2019
  • Silicon carbide (SiC) fiber mats generate large amounts of heat through microwave interactions and are used as heating elements in rapid heat treatment furnaces. However, SiC fibers cool immediately when the microwave power is turned off. Therefore, ceramic layers are inserted between the SiC fiber layers to improve the heat conservation performance of SiC fiber mats. In this study, we fabricated SiC fiber mat composites (SMCs) with ceramic layers under various pressures. The SMC fabricated under 0.007 kPa showed the lowest heat-generating temperature and deviation because less necking was observed between the materials. On the other hand, the SMC fabricated under 0.375 kPa showed the highest heat-generating temperature of 1532.33℃. The SMCs prepared in this study using ceramic powder not only showed heat-generating temperatures comparable to those of conventional SiC fiber mats but also exhibited excellent heat-preserving ability.

Properties of the Electrolyte Separators for Thermal Batteries Using SiOC Mat (SiOC 매트(Mat)를 이용한 열전지용 전해질 격리판 제조 및 특성)

  • Lim, Kyoung-Hoon;Cho, Kwang-Youn;Riu, Doh-Hyung;Shin, Dong-Geun;Jin, Eun-Ju;Kim, Hyoun-Ee;Cheong, Hae-Won;Lee, Hong-Lim
    • Journal of the Korean Ceramic Society
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    • v.46 no.6
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    • pp.648-652
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    • 2009
  • Ceramic fiber separator is the promising material for thermal battery system because it reduces the production cost and offers the potential to a new application compared to a pellet type electrolyte. The electrolyte separator for thermal battery should be easily handled and loaded a large amount of the molten lithium salt. Ceramic fibers were used as an electrolyte separator and the lithium based molten salts were infiltrated into the ceramic filters. Leakage of molten salt (several lithium salts) leads to short-circuit during the thermal battery operation. In this study, a uniform and fine SiOC mat with fibers ranging from 1 to 3 ${\mu}m$ was obtained by electrospinning of polycarbosilane and pyrolysis. The optimum spinning conditions for obtaining fine diameters of SiOC fiber were controlled by the solution composition and concentration, applied voltage and spinning rate, release rate by porosity. The pore structures of the ceramic filter and the melting properties of the lithium salts affected to the electrolyte loading and leakage. The importance of the fiber size and porosity and their control was discussed and the mechanical properties were also discussed.

The PTCR Effect of Semiconducting Zn-Ti-Ni-O Ceramics (Zn-Ti-Ni-O 반도성 세라믹스의 PTCR 현상)

  • Ko, Il-Young;Choi, Seung-Chul;Kim, Hwan
    • Journal of the Korean Ceramic Society
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    • v.30 no.8
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    • pp.609-614
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    • 1993
  • Semiconducting Zn-Ti-Ni-O and Zn-Ti-O system were investigated. The specimens sintered at the temperature between 125$0^{\circ}C$ and 145$0^{\circ}C$ exhibited PTCR effect between -5$0^{\circ}C$ and 35$0^{\circ}C$ with resistivity ration exceeding three decades. Semiconducting Zn-Ti-Ni-O is consisted of two phases, one is n-type ZnO and the other is p-type spinel structure. The mechanism of PTCR effect was explained in relation to the piezoelectric property of ZnO and the residual stress caused by thermal expansion difference between two phases during cooling process.

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