• Journal of the Korean Ceramic Society
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• v.25 no.4
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• pp.309-314
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• 1988

In this study, the effect of the size of sintered body on resonant and filter characteristics in Pb(Sn1/2Sb1/2)O3-PbTiO3 piezo-electric system were investigated. The attenuation characteristics of ring-dot type and ladder type filter were also investigated. As the size of sintered body was decreased, the resonant characteristic(Fr, Fa) and the center frequency(Fo) were increased. As the poling field was increased, the Kp and bandwidth were increased. The big difference between rign-dot type and ladder type was the sharpness of bandwidth, selectivity and the movement of center frequency.

• Journal of the Korean Ceramic Society
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• v.35 no.4
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• pp.399-405
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• 1998

The effect of each factor on the porosity and mean pore size of cordierite(2Mg$.$2{{{{ {Al}_{2 } {O }_{3 } }}$.$5{{{{ {SiO}_{2 } }}) ceram-ics which have been mainly used for hot gas filter was investigated by using orthogonal array. The poros-ity was observed to increase with the content of graphite added as pore-forming material and decrease with increasing talc size. The effects of the other factors the graphite size sintering temperature and hold-ing time at sintering temperature were observed to be small relatively. In case of mean pore size the ef-fect of talc size on the mean pore size of cordierity was investigated to be the largest. The mean pore size was observed to increase with increasing talc size.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.844-847
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• 2009

진공압출성형 공정을 이용하여 한쪽 끝단이 막힌 다공질 탄화규소 캔들 필터를 단일공정으로 제조하는 기술을 확립하였다. 캔들 필터 지지층의 특성 최적화를 위해 탄화규소 출발입자와 무기바인더의 첨가량 변화를 통해 기계적 특성과 기공크기 등의 분석을 수행하여 상용 캔들 필터의 수준에 대응할 수 있는 조합을 도출하였다. Mullite와 clay를 소결조제로 사용하고, $30{\mu}m$ 입도의 탄화규소 입자로 지지층을 제조한 경우, 30% 이상의 기공율을 보유하면서 50 MPa 이상의 상온 3점 굽힘강도를 나타낼 수 있는 조건이 확립됨에 따라 $125{\mu}m$ 입도의 탄화규소와 bi-modal로 사용할 경우, 상용제품의 특성을 상회하는 탄화규소 캔들 필터가 제조될 수 있음을 확인하였다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07a
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• pp.123-126
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• 2002

A proposed multi-layer ceramic (MLC) chip type band-pass filter (BPF) is presented. The MLC chip BPF has the benefits of low cost and small size. The BPF consists of coulped stripline resonators and coupling capacitors. The BPF is designed to have an attenuation pole at below the passband for a receiver band of IMT-2000 handset. The computer-aided design technology is applied for analysis of the BPF frequency characteristics. The passband and attenuation pole depend the coupling between resonators and coupling capacitance. The frequency characterics of the passband and attenuation pole are analysed with the variance of the coupling between resonators and coupling capacitance. An equivalent circuit and structure of MLC chip BPF are proposed. The frequency characteristics of the BPF is well acceptable for IMT-2000 application.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11b
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• pp.152-155
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• 2005

Diesel particulate filter (DPF) is comprised of a number of capillary tubes enclosed by porous ceramic wails, shaped like a plugged duct. Hot gas flows through the DPF along with the exhaust noise from Diesel engine. Based on previous works on the sound propagation through DPF, in this study, losses at entrance, exit, and ceramic walls are considered and the gradients in temperature and flow velocity are considered. Transfer matrix at entrance, monolith, and exit parts are obtained by employing the segmental approach in analyzing the sound propagation through DPF. The predicted transmission loss agrees very well with the empirical one, which is measured by the improved method with correction terms.

• Journal of the Korean Ceramic Society
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• v.23 no.3
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• pp.21-26
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• 1986

In this study the system of $Pb(Mn_{1/3} Nb_{2/3})O_3-PbTiO_3-PbZrO_3$ piexoelectric ceramics was made in the radial mode disk and attenuation characteristic of the desinged ladder type filter was investigated. What is more temperature dependance of resonant frequency and variation of resonant frequency was examined by chan-ging the electrode diameter of piezoelectric resonator. (A Group : De=11mm, B Group : De=7.5mm and C Gro-up : De=5.5mm) Upon investigation it was the following. The center frequency of A, B and c filter showed up in the 200KHz, 270KHz and 380KHz respectively. As the electrode diameter decreased center frequency in creased abruptly. As the Co_2/Co1 increased attenuation characteristics and selectivity was improved. As the x=50. resonant frequ-ency invaried with variation of temperature.

• Transactions of the Korean Society of Automotive Engineers
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• v.4 no.3
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• pp.50-60
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• 1996

We designed and developed the burner which would be adapted on the burner type diesel particulate trap system. The burner type particulate trap system consists of burner system to regenerate to ceramic filter, ceramic filter canister, system controller and etc. Many design factors which affect the performance of the burner system were discussed. We also investigated burner characteristics according to the operating parameters. Burned gas temperature could be controlled better by the 2nd air flow rate than the 1st one. As the space velocity increases, the axial and radial temperature gradients in the filter decreases.

• 한국신재생에너지학회:학술대회논문집
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• 2008.10a
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• pp.246-249
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• 2008

IGCC (석탄가스화 복합발전) 시스템 공정 중 가스화기에서 발생되는 합성가스 내에는 높은 농도의 분진들이 함유되어 있기 때문에 하부 공정들을 보호하기 위해서는 가스화기 후단에 집진장치가 필히 설치되어야 한다. 집진장치의 설계 제작 운전에 있어서 점착성 분진층 부착,분진 브리징, 필터 파손 현상 등과 같은 다양한 문제점들로 인하여 고온의 합성가스를 처리하는 데는 아직 기술적 한계들이 산재해 있는 상황이다. 이와 같은 문제점들은 필터에 부착된 분진층의 탈진성능을 향상시키거나, 필터의 열피로를 줄일 수 있도록 필터 재생을 위한 탈진의 횟수를 줄이는 방법을 통하여 해결될 수 있다. 본 연구에서는 파일롯 규모의 IGCC용 세라믹캔들필터 집진장치에서의 가스 유입 및 탈진 조건에 따른 집진장치의 차압 특성 변화를 수치해석과 실험을 통하여 분석함으로써 탈진성능을 향상시킬 수 있는 조건과 탈진 횟수를 최소화시킬 수 있는 방안을 도출하고자 하였다.

• Journal of the korean Society of Automotive Engineers
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• v.10 no.5
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• pp.54-60
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• 1988

This study is a theoretical analysis and experimental effect of oxygen concentration, exhaust velocity and trap inlet temperature on particulate ignition temperature with installation of ceramic filter trap in diesel engine. So the following results are obtained. 1, Based on the fundamental experiments of the regeneration process, the analytical model was developed and the results from the analytical model agreed with the experiments, then the validity of the model was proved. 2, The ignition temperature for accumulated particulate was proportional to the exhaust velocity and it was known that the optimum exhaust velocity was about 15m/sec. 3, The ignition temperature for accumulated particulate was inversely proportional to the oxygen concentration and the trap inlet temperature, and a minimum oxygen concentration of 5% was required to sustain regeneration. 4, This experimental filter trap(EX-66) is found about 30% of smoke reduction efficiency in comparison with existing muffler.

• Transactions of the Korean Society of Automotive Engineers
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• v.3 no.6
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• pp.41-54
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• 1995

A mathematical model for wall-flow monolith ceramic diesel particulate filter was developed in order to describe the processes which take place in the filter during regeneration. The major output of the model comprises ceramic wall temperature and regeneration time(soot reduction). Various numerical tests were performed to demonstrate how the gas oxygen concentration, flow rate and the initial particulate trap loading affect the regeneration time and peak trap temperature. The model is shown to b in reasonable agreement with the published experimental results. This model can be applied to predict the thermal shock failure due to high temperature during combustion regeneration process.