• Title/Summary/Keyword: ceramic heater

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A Study on the Temperature Distribution at the Surface of Diesel Particulate Filter and Partitioned Electric Heater according to the Conditions of Heating and Flow using an Infrared Temperature Camera (적외선 온도 카메라를 이용한 분할형 전기히터 가열 및 유동 조건에 따른 전기히터와 매연필터 표면에서의 온도 분포에 관한 연구)

  • Lee, Choong-Hoon;Paik, Sung-Chon
    • Journal of the Korean Society of Safety
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    • v.23 no.5
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    • pp.7-14
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    • 2008
  • The temperature distribution in a surface of diesel particulate filter(DPF) was measured using an infrared temperature camera. In order to regenerate the DPF, five partitioned electric heaters were used for heating the ceramic filter. The five partitioned heaters were switched on/off with some time interval one the other. The surface temperature distribution in the ceramic filter and electric heaters were measured with varying both the electrical power supply to the heaters and the mass flow rate of the air supply from a blower. The higher mass flow rate in the DPF system enhanced the uniformity in the surface temperature distribution of the ceramic filter due to effective convection heat transfer. The flow in the monolith ceramic structure of the DPF move mainly in the axial direction, which could be identified from the surface temperature of the ceramic filter.

Effects of ZrO2 Addition on Mechanical Strength and Thermal Shock Resistance of Cordierite-Mullite Ceramics (ZrO2가 코디어라이트-뮬라이트 세라믹스의 기계적 강도 및 내열충격성에 미치는 영향)

  • Lim, Jin-Hyeon;Kim, Shi Yeon;Yeo, Dong-Hun;Shin, Hyo-Soon;Jeong, Dae-yong
    • Korean Journal of Materials Research
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    • v.28 no.12
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    • pp.719-724
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    • 2018
  • Cordierite composed of an alumina-silica-magnesia compound has a low coefficient of thermal expansion(CTE) and excellent thermal shock resistance. It also has a low dielectric constant and high electrical insulation. However, due to low mechanical strength, it is limited for use in a ceramic heater. In this study, $ZrO_2$ is added to an 80 wt% cordierite-20 wt% mullite composition, and the effect of $ZrO_2$ addition on the mechanical strength and thermal shock resistance is investigated. With an increasing addition of $ZrO_2$, cordierite-mullite formed $ZrO_2$, $ZrSiO_4$ and spinel phases. With sintering conducted at $1400^{\circ}C$ with the addition of 5 wt% $ZrO_2$ to 80 wt% cordierite-20 wt% mullite, the most dense microstructure forms along with an excellent mechanical strength with a 3-point flexural strength of 238MPa. When this composition is quenched in water at ${\Delta}T=400^{\circ}C$, the 3-point flexural strength is maintained. Moreover, when this composition is cooled from $800^{\circ}C$ to air, the 3-point flexural strength is maintained even after 100 cycles. In addition, the CTE is measured as $3.00{\times}10^{-6}{\cdot}K^{-1}$ at $1000^{\circ}C$. Therefore, 80 wt% cordierite-20 wt% mullite with 5 wt% $ZrO_2$ is considered to be appropriate as material for a ceramic heater.

Growth of LiF Single Crystal by Floating Zone Method (Floating Zone법에 의한 LiF 단결정 성장)

  • 오원석;신건철
    • Journal of the Korean Ceramic Society
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    • v.27 no.5
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    • pp.631-637
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    • 1990
  • Lithium fluolide single crystals were grown by a floating zone method, with infrared radiation convergence type heater, which is free of contamination from the crucible wall. The crystals grown by this apparatus are 5cm in length and 5-6mm in diameter. The grown cryatal was examined by an optical microscope, XRD, Laue camera, Vickers hardness tester, and FTIR.

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Analysis of heat and fluid flows in an instant water heater according to design parameters of an electric heat device (전기히터의 설계 변수에 따른 순간온수기 열유동 특성 해석)

  • Hui Sun;Joon Hyun Kim;Jaeyong Sung
    • Journal of the Korean Society of Visualization
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    • v.21 no.3
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    • pp.23-32
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    • 2023
  • This study aims to explore the heat transfer and flow phenomena inside an instant water heater and the influence of the design parameters of the water heater on the heating performance was investigated by 3-D numerical simulations considering heat convection. The design parameters are the heating ceramic dimension, the power of the heating device, and the water flow rate. The results show that a reasonable space for the heating device is required to optimize the heating performance. It is desirable to design higher heating device as possible for a given electric power. There exists a critical water flow rate that best meets the heating performance. The change in electric power has no impact on the flow phenomena and heating performance.

Fabrication and Electrical Insulation Property of Thick Film Glass Ceramic Layers on Aluminum Plate for Insulated Metal Substrate (알루미늄 판상에 글라스 세라믹 후막이 코팅된 절연금속기판의 제조 및 절연특성)

  • Lee, Seong Hwan;Kim, Hyo Tae
    • Journal of the Microelectronics and Packaging Society
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    • v.24 no.4
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    • pp.39-46
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    • 2017
  • This paper presents the fabrication of ceramic insulation layer on metallic heat spreading substrate, i.e. an insulated metal substrate, for planar type heater. Aluminum alloy substrate is preferred as a heat spreading panel due to its high thermal conductivity, machinability and the light weight for the planar type heater which is used at the thermal treatment process of semiconductor device and display component manufacturing. An insulating layer made of ceramic dielectric film that is stable at high temperature has to be coated on the metallic substrate to form a heating element circuit. Two technical issues are raised at the forming of ceramic insulation layer on the metallic substrate; one is delamination and crack between metal and ceramic interface due to their large differences in thermal expansion coefficient, and the other is electrical breakdown due to intrinsic weakness in dielectric or structural defects. In this work, to overcome those problem, selected metal oxide buffer layers were introduced between metal and ceramic layer for mechanical matching, enhancing the adhesion strength, and multi-coating method was applied to improve the film quality and the dielectric breakdown property.

A Study on Characteristics of Electric Heater Regeneration Filter Trap in Diesel Engine (디젤기관에서 전기 히터 재생 여과 트랩의 특성에 관한 연구)

  • 류규현;박만재
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.10 no.1
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    • pp.10-15
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    • 2001
  • Urgent increasing of the vehicles influence air pollution and the damage of the plants and animals. Particularly, exhaust-ing particulate of diesel vehicles give serious effect to human life. Therefore, this study aim to reduce amount of particulate and to contribute developing after-treatment in diesel engine. Through the experimental and theoretical study about charac-teristics of the electric heat regeneration, various results are obtained.

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Reliability Evaluation on PTC Heater Using Accelerated Life Test and Failure Analysis (고장 분석과 가속 수명시험을 통한 PTC 히터의 신뢰성 평가)

  • Choi, Hyoung-Seuk
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.28 no.12
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    • pp.843-846
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    • 2015
  • In this paper, the failure mechanism of PTC heater were examined closely by failure analysis and based on it, accelerated life test were conducted. Finally, life distribution and acceleration model were established. The failure mechanism of PTC heater such as crack, increase of resistance due to heating were identified. Two acceleration factors such as temperature, humidity were chosen with two levels each and accelerated life test were done. Life distribution were identified as Weibull distribution with shape parameter 5.4 and Temperature-Humidity model was fitted as an acceleration model.

Development of Electroconductive SiC Ceramic Heater by Spark Plasma Sintering (방전플라즈마 소결에 의한 자기 통전식 SiC계 세라믹 발열체 개발)

  • Shin, Yong-Deok;Choi, Won-Seok;Ko, Tae-Hun;Lee, Jung-Hoon;Ju, Jin-Young
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.58 no.4
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    • pp.770-776
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    • 2009
  • The composites were fabricated by adding 0, 15, 30, 45[vol.%] $ZrB_2$ powders as a second phase to SiC matrix. The physical, mechanical and electrical properties of electroconductive SiC ceramic composites by spark plasma sintering(SPS) were investigated. Reactions between ${\beta}$-SiC and $ZrB_2$ were not observed in the XRD and the phase analysis of the electroconductive SiC ceramic composites. The relative density of mono ${\beta}$-SiC, ${\beta}$-SiC+15[vol.%]$ZrB_2$, ${\beta}$-SiC+30[vol.%]$ZrB_2$ and ${\beta}$-SiC+45[vol.%]$ZrB_2$ composites are respectively 99.24[%], 87.53[%], 96.41[%] and 98.11[%] Phase analysis of the electroconductive SiC ceramic composites by XRD revealed mostly of ${\beta}$-SiC, $ZrB_2$ and weakly of $ZrO_2$ phase. The flexural strength showed the lowest of 114.44[MPa] for ${\beta}$-SiC+15[vol.%]$ZrB_2$ powders and showed the highest of 210.75[MPa] for composite no added with $ZrB_2$ powders at room temperature. The trend of the mechanical properties of the electroconductive SiC ceramic composites is accorded with the trend of the relative density. The electrical resistivity of the electroconductive SiC ceramic composites decreased with increased $ZrB_2$ contents. The electrical resistivity of mono ${\beta}$-SiC, ${\beta}$-SiC+15[vol.%]$ZrB_2$, ${\beta}$-SiC+30[vol.%]$ZrB_2$ and ${\beta}$-SiC+45[vol.%]$ZrB_2$ composites are respectively $4.57{\times}10^{-1},\;2.13{\times}10^{-1},\;2.68{\times}10^{-2}\;and\;1.99{\times}10^{-2}[{\Omega}{\cdot}cm]$ at room temperature. The electrical resistivity of mono ${\beta}$-SiC and ${\beta}$-SiC+15[vol.%]$ZrB_2$ are negative temperature coefficient resistance(NTCR) in temperature ranges from $25[^{\circ}C]\;to\; 100[^{\circ}C]$. The electrical resistivity of ${\beta}$-SiC+30[vol.%]$ZrB_2$ and ${\beta}$-SiC+45[vol.%]ZrB_2$ are positive temperature coefficient resistance(PTCR) in temperature ranges from $25[^{\circ}C]\;to\;100[^{\circ}C]$. It is convinced that ${\beta}$-SiC+30[vol.%]$ZrB_2$ composites by SPS for heater or ignitors can be applied.

Development of a PTC Heater for Supplementary Heating in a Diesel Vehicle (디젤 차량의 보조 난방을 위한 PTC 히터 개발)

  • Shin, Yoon Hyuk;Kim, Sung Chul
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.2
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    • pp.666-671
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    • 2014
  • Using positive temperature coefficient (PTC) heater as supplementary heating for diesel engine vehicles with low heat source is a good method to enhance the heating performance during cold start. In this study, the PTC elements were made by using screen printing process for forming ohmic contact layer, and prototype of PTC heater was designed and made for a diesel engine vehicle. In process of designing the PTC heater, the thermal flow analysis of PTC element modules was conducted for verifying the effect of the shapes of contact surface between each of the components (cooling fin, insulator, ceramic element). We also investigated the performance characteristic (heating capacity, energy efficiency, pressure drop) of the PTC heater through the experiments. Therefore, the experimental results indicated that prototype of PTC heater had satisfactory performance. This study will be basis for improving the manufacturing process and increasing the performance of the PTC element and heater.

Crystal Growth of Sapphire (Sapphire 결정성장)

  • ;;S, Kimura
    • Journal of the Korean Ceramic Society
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    • v.23 no.1
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    • pp.21-26
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    • 1986
  • By the floating zone method with infrared radiation convergence type heater homogeneously $Cr^{3+}$ doped alu-mina single crystal was obtained. And sizx {1010} facets appeared at the surface of [0001] grown crystals. $ZrO_2$ and $HfO_2$ precipitated as secondary phase and were not doped in the crystals. We found that the dist-ribution of the secondary phase which was mainly located at the surface and the peripheral region was closely related to the flow pattern of melt zone.

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