Nonideal Flow Behavior Analysis of Atmospheric Thermal Silicon Oxidation Reactors by the Residence Time Distribution Technique

AbstractThis study explores aspects of the fluid dynamics of CMP processes. The residence time distribution of slurry under the wafer is experimentally determined and used to calculate the Dispersion Number (Δ) of the fluid in the wafer-pad region based on a dispersion model for non-ideal reactors. Furthermore, lubrication theory is used to explain flow behaviors at various operating conditions. Results indicate that at low wafer pressure and high relative pad-wafer velocity, the slurry exhibits nearly ideal plug flow behavior. As pressure increases and velocity decreases, flow begins to deviate from ideality and the slurry becomes increasingly more mixed beneath the wafer. These phenomena are confirmed to be the result of variable slurry film thicknesses between the pad and the wafer, as measured by changes in the coefficient of friction (COF) in the pad-wafer interface.

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Gas flow behavior and residence time distribution in a rough-cut cyclone

Chemical Engineering Journal ◽

10.1016/j.cej.2004.06.014 ◽

2005 ◽

Vol 106 (1) ◽

pp. 43-52 ◽

Cited By ~ 8

Author(s):

C ZHONGXI ◽

S GUOGANG ◽

J JIAO ◽

Y ZHENG ◽

G BING ◽

...

Keyword(s):

Residence Time ◽

Time Distribution ◽

Residence Time Distribution ◽

Gas Flow ◽

Flow Behavior ◽

Rough Cut

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Research on Optimization of Flow Field in 60t Tow-Strand Tundish by Hydraulic Model

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.605-607.1311 ◽

2012 ◽

Vol 605-607 ◽

pp. 1311-1316

Author(s):

Jian Jun Zhang ◽

Wen Fang Gao ◽

Zhu Gang Peng

Keyword(s):

Flow Field ◽

Residence Time ◽

Time Distribution ◽

Residence Time Distribution ◽

Flow Behavior ◽

Hydraulic Model ◽

Dead Volume ◽

Average Residence Time ◽

Original Scheme ◽

The Dead

The original scheme flow behavior of WISCO 60t two-strand tundish was investigated by means of hydraulic model. Optimized scheme was selected by flow field Character analyzing and residence time distribution (RTD) curves analyzing of each scheme. The results show that the dead volume Vd of optimized scheme decreases to 5.33%, reduced by 77.4% compared with the original scheme. The average residence time Ta of optimized scheme increases to 364.5s, increased by 70.5s compared with the original scheme. The optimized scheme favors more reasonable flow field and inclusions removing in the tundish. It is more adaptive than the original scheme for the tow-strand tundish.

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Modeling of Vortex-Flow Solar Reactor via Ideal Reactors in Series Approach

ASME 2010 4th International Conference on Energy Sustainability, Volume 1 ◽

10.1115/es2010-90324 ◽

2010 ◽

Cited By ~ 1

Author(s):

Nesrin Ozalp ◽

Vidyasagar Shilapuram ◽

D. Jayakrishna

Keyword(s):

Residence Time ◽

Time Distribution ◽

Residence Time Distribution ◽

Vortex Flow ◽

Flow Reactor ◽

Flow Behavior ◽

Plug Flow ◽

Flow Reactors ◽

In Series ◽

Sweeping Gas

In this work, we present a thorough reaction engineering analysis on the modeling of a vortex-flow reactor to show that commonly practiced one-plug reactor approach is not sufficient to explain the flow behavior inside the reactor. Our study shows that N-plug flow reactors in series is the best approach in predicting the flow dynamics based on the computational fluid dynamics (CFD) simulations. We have studied the residence time distribution using CFD by two different methods. The residence time distribution characteristics are calculated by approximating the real reactor as N-ideal reactors in series, and then estimated the number of ideal reactors in series for the model. We have validated our CFD model by comparing the simulation results with experimental results. Finally, we have done a parametric study with a different sweeping gas to identify the best screening gas to avoid carbon deposition inside the vortex-flow reactor. Our results have shown that hydrogen is a better screening gas than argon.

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Investigation on a Soft Tubular Model Reactor Based on Bionics of Small Intestine – Residence Time Distribution

International Journal of Food Engineering ◽

10.1515/ijfe-2014-0048 ◽

2014 ◽

Vol 10 (4) ◽

pp. 645-655 ◽

Cited By ~ 4

Author(s):

Renpan Deng ◽

Liqing Pang ◽

Yufen Xu ◽

Lin Li ◽

Xuee Wu ◽

...

Keyword(s):

Small Intestine ◽

Residence Time ◽

Time Distribution ◽

Residence Time Distribution ◽

Flow Behavior ◽

Tubular Reactor ◽

Tubular Reactors ◽

Fluid Particles ◽

Mucosal Surface Area ◽

Structure And Functions

Abstract The human small intestine is responsible for virtually all nutrient uptake and more than 95% of the water absorption in digestion, which is attributed to the vast mucosal surface area and the peristalsis of small intestine. Under the broad conceptual framework of bio-inspired chemical process engineering, by mimicking the structure and functions of small intestine, a flexible tubular reactor with villous protrusions distributed evenly on the inner wall was designed and constructed in this study. In order to understand the flow behavior in the reactor, the residence time distribution (RTD) of fluid particles in the reactor was measured by introducing electrochemical active tracer. Also, a simple mechanism of peristalsis was introduced, and its effects on the RTD in the reactor were investigated. The experimental results showed that the tailing of RTD function curve in the small intestine model reactor was extended significantly compared to a normal tubular reactors. The residence time and mixing of fluid (particles) in the reactor can be regulated efficiently by controlling the peristaltic actions (frequency and location).

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