• Title, Summary, Keyword: Taylor reactor

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Numerical Studies of Flow Characteristics and Particle Residence Time in a Taylor Reactor (테일러 반응기의 유동특성과 입자 체류시간에 관한 수치적 연구)

  • Lee, Hyeon Kwon;Lee, Sang Gun;Jeon, Dong Hyup
    • Applied Chemistry for Engineering
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    • v.26 no.1
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    • pp.67-73
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    • 2015
  • Using a computational fluid dynamics technique, the flow characteristics and particle residence time in a Taylor reactor were studied. Since flow characteristics in a Taylor reactor are dependent on the operating conditions, effects of the inlet flow velocity and reactor rotational speed were investigated. In addition, the particle residence time of $LiNiMnCoO_2$ (NMC), which is a cathode material in lithium-ion battery, is estimated in the Taylor vortex flow (TVF) region. Without considering the complex chemical reaction at the inlet, the effect of Taylor flow was studied. The results show that the particle residence time increases as the rotating speed increased and the flow rate decreased.

Numerical Study on Fluid Flow Characteristics in Taylor Reactor using Computational Fluid Dynamics (CFD를 이용한 테일러 반응기의 유동 특성에 관한 수치적 연구)

  • Lee, Seung-Ho;Shim, Kyu Hwan;Jeon, Dong Hyup
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.40 no.1
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    • pp.9-19
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    • 2016
  • This study investigated the variations of Taylor flow and particle residence time in a Taylor reactor according to the changes of angular velocity and inlet velocity using computational fluid dynamics technique. The results showed that the fluid in a reactor became unstable with an increase of angular velocity. The flow moved to the regions of CCF, TVF, WVF and MWVF resulting in an increase of Reynolds number. Accordingly, the flow characteristics were different for each regions. We confirmed that the inlet velocity influences the Taylor flow. The particle residence time and standard deviation increased with an increase of angular velocity and a decrease of inlet velocity.

Three-dimensional Fluid Flow Analysis in Taylor Reactor Using Computational Fluid Dynamics (CFD를 이용한 테일러 반응기의 3차원 유동해석)

  • Kwon, Seong Ye;Lee, Seung-Ho;Jeon, Dong Hyup
    • Applied Chemistry for Engineering
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    • v.28 no.4
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    • pp.448-453
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    • 2017
  • We conducted the three-dimensional fluid flow analysis in a Taylor reactor using computational fluid dynamics (CFD). The Taylor flow can be categorized into five regions according to Reynolds number, i.e., circular Couette flow (CCF), Taylor vortex flow (TVF), wavy vortex flow (WVF), modulated wavy vortex flow (MWVF), and turbulent Taylor vortex flow (TTVF), and we investigated the flow characteristics at each region. For each region, the shape, number and length of vortices were different and they influenced on the bypass flow. As a result, the Taylor vortex was found at TVF, WVF, MWVF and TTVF regions. The highest number of Taylor vortex was observed at TVF region, while the lowest at TTVF region. The numerical model was validated by comparing with the experimental data and the simulation results were in good agreement with the experimental data.

Numerical Study of Aggregation and Breakage of Particles in Taylor Reactor (테일러 반응기 내의 입자응집과 분해에 관한 수치 연구)

  • Lee, Seung Hun;Jeon, Dong Hyup
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.40 no.6
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    • pp.365-372
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    • 2016
  • Using the computational fluid dynamics (CFD) technique, we simulated the fluid flow in a Taylor reactor considering the aggregation and breakage of particles. We calculated the population balance equation (PBE) to determine the particle-size distribution by implementing the quadrature method-of-moment (QMOM). It was used that six moments for an initial moments, the sum of Brownian kernel and turbulent kernel for aggregation kernel, and power-law kernel for breakage kernel. We predicted the final mean particle size when the particle had various initial volume fraction values. The result showed that the mean particle size and initial growth rate increased as the initial volume fraction of the particle increased.

The effect of vibration of the water surface for hydrogen gas generation by plasma electrical discharge (비열플라즈마에 의한 수소가스발생에 미치는 수표면 진통효과)

  • Kim, Jong-Seog;Park, Jae-Yoon;Jung, Jang-Gun;Kim, Tae-Yong;Lee, Jae-Dong;Koh, Hee-Seog;Lee, Hyun-Woo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.115-119
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    • 2004
  • This paper is investigated about the effect of vibration of the water surface for hydrogen gas generation by non-thermal plasma. The vibration of the water surface is more powerful with increasing applied voltage. In this experimental reactor which is made of multi-needle and plate, the maximum acquired hydrogen production rate is about 6.8[ml/sec]. Although the generation of hydrogen gas is increased with elevating time, it is saturated after specific time due to the volume of reactor and the saturation of taylor cone.

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Taylor Series-Based Long-Term Creep-Life Prediction of Alloy 617 (Taylor 급수를 이용한 617 합금의 장시간 크리프 수명 예측)

  • Yin, Song-Nan;Kim, Woo-Gon;Park, Jae-Young;Kim, Soen-Jin;Kim, Yong-Wan
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.34 no.4
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    • pp.457-465
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    • 2010
  • In this study, a Taylor series (T-S) model based on the Arrhenius, McVetty, and Monkman-Grant equations was developed using a mathematical analysis. In order to reduce fitting errors, the McVetty equation was transformed by considering the first three terms of the Taylor series equation. The model parameters were accurately determined by a statistical technique of maximum likelihood estimation, and this model was applied to the creep data of alloy 617. The T-S model results showed better agreement with the experimental data than other models such as the Eno, exponential, and L-M models. In particular, the T-S model was converted into an isothermal Taylor series (IT-S) model that can predict the creep strength at a given temperature. It was identified that the estimations obtained using the converted ITS model was better than that obtained using the T-S model for predicting the long-term creep life of alloy 617.

Comparison of Matrix Exponential Methods for Fuel Burnup Calculations

  • Oh, Hyung-Suk;Yang, Won-Sik
    • Nuclear Engineering and Technology
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    • v.31 no.2
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    • pp.172-181
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    • 1999
  • Series expansion methods to compute the exponential of a matrix have been compared by applying them to fuel depletion calculations. Specifically, Taylor, Pade, Chebyshev, and rational Chebyshev approximations have been investigated by approximating the exponentials of bum matrices by truncated series of each method with the scaling and squaring algorithm. The accuracy and efficiency of these methods have been tested by performing various numerical tests using one thermal reactor and two fast reactor depletion problems. The results indicate that all the four series methods are accurate enough to be used for fuel depletion calculations although the rational Chebyshev approximation is relatively less accurate. They also show that the rational approximations are more efficient than the polynomial approximations. Considering the computational accuracy and efficiency, the Pade approximation appears to be better than the other methods. Its accuracy is better than the rational Chebyshev approximation, while being comparable to the polynomial approximations. On the other hand, its efficiency is better than the polynomial approximations and is similar to the rational Chebyshev approximation. In particular, for fast reactor depletion calculations, it is faster than the polynomial approximations by a factor of ∼ 1.7.

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Xenon in molten salt reactors: The effects of solubility, circulating particulate, ionization, and the sensitivity of the circulating void fraction

  • Price, Terry J.;Chvala, Ondrej;Taylor, Zack
    • Nuclear Engineering and Technology
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    • v.52 no.6
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    • pp.1131-1136
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    • 2020
  • Xenon behaves differently in molten salt reactors (MSRs) compared to solid fuel reactors. This behavior needs exploring due to the large reactivity effect of the 135Xe isotope, given the current interest in MSR power plant development for commercial deployment. This paper focuses on select topics in xenon transport, reviews relevant past works, and proposes specific research questions to advance the state of the art in each of the focus areas. Specifically, the paper discusses the issue of xenon solubility in MSRs, the behavior of particulates circulating in MSR fuel salt and its influence on the xenon transport, the possibility of ionization of xenon atoms which changes its effective size and thus affects its mass transport, and finally the issue of circulating void fraction and how it is measured. This work presents specific recommendations for MSR designers to research the limits of Henry's law validity, circulating particulate scrubbers, validity of mass transport coefficients in high radiation fields, and the effects of pump speed on circulating void fraction.

The Hydrogen Generation's Characteristics using Plasma Reactor of Multi-needle Electrode Type (다중침전극형 플라즈마 반응기를 이용한 수소발생 특성)

  • Park, Jae-Yoon;Kim, Jong-Seok;Jung, Jang-Gun;Goh, Hee-Seok;Park, Sang-Hyun;Lee, Hyun-Woo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.17 no.11
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    • pp.1246-1251
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    • 2004
  • This paper is investigated about the effect of carrier gas type and the humidity for generating hydrogen gas. The vibration of the water surface is more powerful with increasing applied voltage. In this experimental reactor which is made of multi-needle and plate, the maximum acquired hydrogen production rate is about 3500 ppm. In the experimental result of generating hydrogen gas by non-thermal plasma reactor, the rate of generating hydrogen gas is different with what kind of carrier gas is. We used two types of carrier gas, such as $N_2$ and He. $N_2$ as carrier gas is more efficient to generate hydrogen gas than He because $N_2$ is reacted with $O_2$, which is made from water dissociation. In comparison with water droplet by humidifier and without water droplet by humidifier, the generation of hydrogen gas is decreased in case of water droplet by humidifier. That is the result that the energy for water dissociation is reduced on water surface because a part of plasma energy is absorbed at the small water molecular produced from humidifier.