• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.3
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• pp.205-212
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• 2000

Experimental investigations on the removal of protein, total suspended solids and turbidity from aquacultural water were carried out by using three types of foam separator: counter current air driven type foam separator (CCADFS), high speed aeration type foam separator (HSAFS) and venturi type foam separator (VFS). The decrease of flow rate by CCADFS, HSAFS and VFS were $0.4,\;66.1,\;77.2 {\%}$ respectively. Protein removal rates by three types foam separator were decreased with the increased hydraulic residence time (HRT). Bellw 0.32 minute and 0.21 minute of hydraulic residence times, protein removal rate of HSAFS and YES was higher than that of CCADFS, respectively. Protein removal rate of VFS was lower than that of HSAFS at any HRT. As increasing the HRT, protein removal efficiency of CCADFS was increased, but that of HSAFS and VES were decreased. The changes of removal rates and efficiencies of total suspended solid and turbidity were similar to proteins.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.30 no.6
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• pp.46-52
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• 2002

Characteristics of flow rate control has been studied for a cavitating venturi adopted in a liquid rocket propellant feed system. Both experiment and numerical simulation have been performed to give about 10% discrepancy of mass flow rate for cavitating flow regime. Mass flow rate is confirmed to be saturated for pressure difference higher than $3{\times}10^5$pa when the upstream pressure is fixed to $22.8{\times}10^5$pa and the downstream pressure is varied. The evaporation amount depends substantially to non-condensable gas concentration. However the mass flow rate characteristics is relatively insensitive to the mass fraction of non-condensable gas. So it reduces by only 2% when the non-condensable gas concentration is increased from 1.5PPM to 150PPM. From the previous comparison the expansion of the non-condensable gas and the evaporation of liquid are verified to gave same effect to the pressure recovery pattern.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.05a
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• pp.284-285
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• 2000

분산된 공기 기포에 의해 고형물을 제거하는 포말분리법은 30 $\mu\textrm{m}$이하의 미세 입자와 용존 고형물을 매우 효율적이면서도 경제적으로 운전을 할 수 있고 연속 운전이 가능하며 역세척이 필요 없다는 장점을 지니고 있다((Clarke and Wilson. 1983). 현재 사용되고 있는 포말분리장치는 공기의 공급방식과 유체과 공기의 접촉방향에 따라 항류 공기구동식(counter current air driven type, CCAD), 고속 폭기식(high speed aeration type, HSA), 벤튜리식(venturi type) 등이 있으나 현재까지 우리나라에서 연구되어 오고있는 포말분리 장치는 공기구동 방식이 전부이다. (중략)

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.9
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• pp.6397-6402
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• 2015

This research was performed to review operating parameters, optimum condition and check characteristic of microbubble generation for using bubble size distribution according to venturi specification. Optimum operating condition have airflow rate 0.3 LPM, 3 bar(pressure tank) and connecting nozzle directly(without valve), it is advantageous to generate microbubble. In case of characteristic of microbubble generation according to venturi specification, effect that nozzle specification affects bubble size distribution is low impact. But considering performance aspects, when using nozzle that throat diameter 3-4 mm, $D_{50}$ are $54.98-61.19{\mu}m$(D3L15, D4L15), fraction of bubble less than $50{\mu}m$ are 0.326, 0.345. And it is superior to others. Besides, $D_{50}$ and fraction of bubble less than $50{\mu}m$ of throat length 20 mm are $49.40-54.98{\mu}m$, 0.447, respectively And nozzle that throat length 20 mm is relatively tendency to generate microbubble stably.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.23 no.8
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• pp.543-548
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• 2011

New concept of wind energy conversion system is proposed to increase the energy density at a given working space. The quality of wind for wind power generation is depend on its direction and speed. However, the quality is not good on land because wind direction is changeable all the time and the speed as well. The most popularly operated wind turbine system is an axial-flow free turbine. But its conversion efficiency is less than 30% and even less than 20% considering the operating time. In this research, a cross-flow type wind turbine system is proposed with a convergent-divergent duct system to accelerate the low speed wind at the inlet of the wind turbine. Inlet guide vane is also introduced to the wind turbine system to have continuous power generation under the change of wind direction. In here, the availability of wind energy generation is evaluated with the change of the size of the inlet guide vane and the optimum geometry of the turbine impeller blade was found for the innovative wind power generation system.