• Title/Summary/Keyword: Mixing Intensity

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Numerical Study on Improvement of Mixing Equipment' Plan in a Water Treatment Plant (수리해석을 이용한 정수장내 혼화장치 설계 개선에 관한 연구)

  • Oh, S.Y.;Hyun, D.S.;Oh, J.J.;Lee, S.H.;Lee, N.Y.
    • Proceedings of the KSME Conference
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    • 2001.06e
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    • pp.777-782
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    • 2001
  • In this study, we used In-line orifice mixer for efficient chemicals mixing in water treatment. The method of using In-line orifice mixer has been already proved the improvement of water treatment efficiency. Numerical study was performed using FLUENT, a commercial code, to standard design and production of effective In-line orifice mixer. As variable for exactly standardizing, a proper ratio between an outer diameter of cone and a diameter of pipe, a distance between cone and orifice, a determination of orifice diameter for an optimal mixing, a distance between injection nozzle's position and cone, Numerical study has been performed for optimal standard and analyzed flow field on a basis of turbulent intensity in an orifice downstream.

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Visualization for the mixing state of a batch-type ultrasonic mixer for its application to the microdevice (마이크로믹서에의 응용을 위한 batch type 초음파믹서의 혼합 상태 가시화)

  • Heo, Pil-Woo;Yoon, Eui-Soo;Koh, Kwang-Sik
    • Journal of Sensor Science and Technology
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    • v.14 no.1
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    • pp.47-51
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    • 2005
  • An active ${\mu}$-mixer is important in Bio-MEMS and ${\mu}$-TAS. The mixing state depends on some kinds of factors including the intensity of ultrasonic radiation. We have visualized the mixing state of the mixing chamber with radiation time and presented the influence of the driving voltage in this research. It will be possible to compare the performances of the ultrasonic radiation parts used in the active ${\mu}$-mixer using this method.

Numerical Study on effective Mixing Chemical Liquid using Hydraulic Energy in a Water Treatment Plant (정수장내 수류에너지를 이용한 액체약품의 효율적인 혼화를 위한 수리해석)

  • Song K. S.;Oh S. Y.
    • 한국전산유체공학회:학술대회논문집
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    • 2001.10a
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    • pp.132-137
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    • 2001
  • We used In-line orifice mixer for efficient chemicals mixing in water treatment. The method of using In-line orifice mixer has been already proved the improvement of water treatment efficiency. Code of computational fluid dynamics for numerical analysis was performed using FLUENT, a commercial code. As variable for exactly standardizing, a proper ratio between an outer diameter of deflector and a diameter of pipe, the distance between deflector and orifice, a determination of orifice diameter fur an optimal mixing, a distance between injection nozzle's position and cone, Numerical study has been performed for optimal standard and analyzed flow field on a basis of turbulent intensity in an orifice downstream.

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Fluoride Removal Using Ready-Mixed Concrete Sludge (레미콘 슬러지를 이용한 불소제거)

  • Kang, Min-Koo;Shin, Gwan-Woo;Lee, Sang-Ill
    • Journal of Korean Society of Environmental Engineers
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    • v.35 no.11
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    • pp.803-808
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    • 2013
  • The purpose of this study was performed to investigate the optimum conditions of pH, concrete sludge, seed dosage, mixing intensity, operation time in treating fluoride-containing wastewater as $CaF_2$ using the ready-mixed concrete sludge. Considering fluoride removal, water content, that pH 6, concrete sludge dosage of 10 g/L, Seed dosage ($CaF_2$) of 2 g/L, mixing intensity of 100 rpm and operation time of 60 min were found to be optimum. Correspondingly, removal of fluoride and water content was about 85% and 64%, respectively. Increase in amount of seed dosage did not affect fluoride removal efficiency. but the result that the water content is decreased was shown up in occuring the solid-liquid separation well.

A Study on the Mixing Characteristics in Complex Turbulent Flow by a Laser Induced Fluorescence Method (레이저 형광여기법(LIF)를 이용한 복잡 난류유동장의 혼합특성에 관한 연구)

  • Kim, Kyung-Chun;Jeong, Eun-Ho
    • Proceedings of the KSME Conference
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    • 2001.06e
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    • pp.542-547
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    • 2001
  • A non-intrusive Planar Laser-Induced Fluorescence(PLIF) technique was applied to study the turbulent mixing process in a Rushton turbine reactor. Instantaneous and ensemble averaged concentration fields are obtained by measuring the fluorescence intensity of Rhodamine B tracer excited by a thin Nd:Yag laser sheet illuminating the whole center plane of the stirred tank. The gray level images captured by a 14-bit cooled CCD camera can be transformed to the local concentration values using a calibration matrix. The dye injection point was selected at the tank wall with three quarter height (3/4H) from the tank bottom to observe the mixing characteristics in upper bulk flow region. There exist distinct two time scales: the rapid decay of mean concentration in each region after the dye infusion reflects the large scale mixing while the followed slow decay reveals the small scale mixing. The temporal change of concentration probability functions conjectures the two sequential processes in the batch type mixing. An inactive column of water existed above the impeller disk, in which the fluid rotates with the shaft but is isolated from the mean bulk flow.

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A Study on the Mixing Characteristics in a Rushton Turbine Reactor by a Laser Induced Fluorescence Method (레이저 형광여기법(LIF)를 이용한 러쉬톤 터빈 교반기의 혼합특성에 관한 연구)

  • Jeong, Eun-Ho;Kim, Gyeong-Cheon
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.26 no.8
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    • pp.1145-1152
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    • 2002
  • A non-intrusive Planar Laser-Induced Fluorescence(PLIF) technique was applied to study the turbulent mixing process in a Rushton turbine reactor. Instantaneous and ensemble averaged concentration fields was obtained by measuring the fluorescence intensity of Rhodamine B tracer excited by a thin Nd:Yag laser sheet illuminating the whole center plane of the stirred tank. The gray level images captured by a 14-bit cooled CCD camera could be transformed to the local concentration values using a calibration matrix. The dye injection point was selected at the tank wall with three quarter. height (3/4H) from the tank bottom to observe the mixing characteristics in upper bulk flow region. There exist distinct two time scales: the rapid decay of mean concentration after the dye infusion reflects the large scale turbulent mixing while the fellowed slow decay reveals the small scale molecular mixing. The temporal change of concentration variance field conjectures the two sequential processes for the batch type mixing. An inactive column of water is existed above the impeller disk, in which the fluid rotates with the shaft but is isolated from the mean bulk flow.

Experimental Study on the Optimum Operation Conditions of Rapid Mixing Impellers for an Effective W.T.P. Design (정수장 효율 향상을 위한 혼화기별 최적 운전조건 산정에 관한 실험적 연구)

  • Son, Gwang-Ik
    • Journal of Korea Water Resources Association
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    • v.30 no.6
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    • pp.731-741
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    • 1997
  • Optimum design conditions of rapid mixing impellers for an effective Water Treatment Plant operation were experimentally studied by thorough examination of parameters, such as impeller type and detention time. which govern the removal efficiency of turbidity. It was found that the impeller type is one of the major parameters governing the economic power consumption and the efficiency of turbidity removal. The experimental results showed that not only the velocity gradient G but also a new design guide. so called mixing energy per unit volume of raw water, could be used as a design and operation guides for rapid mixing in W.T.P.

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Effect of Calcium Sources for the Treatment of Wastewater Containing High Fluoride (고농도의 불소함유폐수 처리시 칼슘원에 따른 영향)

  • Kim, Seung-Ha;Kim, Keum-Yong;Ryu, Hong-Duck;Lee, Sang-Ill
    • Journal of Korean Society of Environmental Engineers
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    • v.33 no.5
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    • pp.307-313
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    • 2011
  • As production of LCD increases, it has become necessary to find an economically efficient way of treating LCD wastewater with high concentration of fluoride. This study focuses on the calcium sources : $CaCl_2$, $Ca(OH)_2$ and $CaCO_3$ for the treatment of the LCD wastewater including high concentration of fluoride. Of course considering removal efficiency and economical aspect, study is continued. Then this study have objective giving aid to field. Consequently, each calcium source's removal efficiency was measured in various pH, calcium dosage, reaction time, and mixing intensity. The optimum operational conditions for $CaCl_2$ were found to be pH of 7, calcium dosage of 0.4[Ca]/[F] (mol / mol), 1 hr of operation and 200 rpm of mixing intensity. For $Ca(OH)_2$, they were pH of 7, calcium dosage of 30 mL/L, 1 hr of operation, and 200 rpm of mixing intensity. While $CaCO_3$ had operational conditions of pH of 4, calcium dosage of 30 mL/L, 1 hr operation and 200 rpm of mixing intensity. But it is recommended to use calcium sources according to various field conditions.