• Title/Summary/Keyword: Air circulation device

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Development of Bubble Detector for Extracorporeal Circulation Support System (체외 순환 보조 장치 위한 공기방울 감지 장치 개발)

  • Lee, Hyuk-Soo
    • Journal of the Institute of Convergence Signal Processing
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    • v.11 no.4
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    • pp.298-302
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    • 2010
  • Extracorporeal circulation support system is a device for repiratory and heart failure treatment, and there have been many trials for development and clinical application in the world. These devices need to be careful while using is air embolism. Air embolism can be a lethal complication of surgical procedures during which venous pressure at the site of surgery is sub-atmospheric or air is forced under pressure into a body cavity or using extracorporeal circulation support system. To solve the problem, we developed the air detector using relative dielectric constant change. In experiments with a mock circulation system, the proposed system showed a signal difference depending on the amount of air in the tube.

A Study on the Ralstonia Solanacearum Inactivation using Improved Plasma Process (개선된 플라즈마 공정을 이용한 Ralstonia Solanacearum 불활성화에 관한 연구)

  • Kim, Dong-Seog;Park, Young-Seek
    • Journal of Environmental Science International
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    • v.23 no.3
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    • pp.369-378
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    • 2014
  • Effect of improvement of the dielectric barrier discharge (DBD) plasma system on the inactivation performance of bacteria were investigated. The improvement of plasma reactor was performed by combination with the basic plasma reactor and UV process or combination with the basic plasma reactor and circulation system which was equipped with gas-liquid mixer. Experimental results showed that tailing effect was appeared after the exponential decrease in basic plasma reactor. There was no enhancement effect on the Ralstonia Solanacearum inactivation with combination of basic plasma process and UV process. The application of gas-liquid mixing device on the basic plasma reactor reduced inactivation time and led to complete sterilization. The effect existence of gas-liquid mixing device, voltage, air flow rate (1 ~ 5 L/min), water circulation rate (2.8 ~ 9.4 L/min) in gas-liquid mixing plasma, plasma voltage and UV power of gas-liquid mixing plasma+UV process were evaluated. The optimum air flow rate, water circulation rate, voltage of gas-liquid mixing system were 3 L/min, 3.5 L/min and 60 V, respectively. There was no enhancement effect on the Ralstonia Solanacearum inactivation with combination of gas-liquid mixing plasma and UV process.

Natural Circulation Flow Investigation in a Rectangular Channel (사각 단면 채널에서의 자연순환 유동에 관한 연구)

  • Ha, Kwang-Soon;Kim, Jae-Cheol;Park, Rae-Joon;Kim, Sang-Baik;Hong, Seong-Wan
    • Proceedings of the KSME Conference
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    • 2007.05b
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    • pp.3086-3091
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    • 2007
  • When a molten corium is relocated in a lower head of a reactor vessel, the ERVC (External Reactor Vessel Cooling) system is actuated as coolant is supplied into a reactor cavity to remove a decay heat from the molten corium during a severe accident. To achieve this severe accident mitigation strategy, the two-phase natural circulation flow in the annular gap between the external reactor vessel and the insulation should be formed sufficiently by designing the coolant inlet/outlet area and gap size adequately on the insulation device. For this reason, one-dimensional natural circulation flow tests were conducted to estimate the natural circulation flow under the ERVC condition of APR1400. The experimental facility is one-dimensional and scaled-down as the half height and 1/238 rectangular channel area of the APR1400 reactor vessel. As the water inlet area increased, the natural circulation mass flow rate asymptotically increased, that is, it converged at a specific value. And the circulation mass flow rate also increased as the outlet area, injected air flow rate, and outlet height increased. But the circulation mass flow rate was not changed along with the external water level variation if the water level was higher than the outlet height.

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Freeze Protection for Passive Solar Water Heating System (자연순환형 태양열온수기 동파방지기술)

  • Kim, Jong-Hyun;Hong, Hi-Ki;Chung, Jae-Dong
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.23 no.5
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    • pp.327-333
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    • 2011
  • In the present work, a new freeze protection method has been proposed for a natural circulation system of solar water heater. Though electrothermal wire is popularly used for the purpose, there are freezing troubles by wire cut-off and shortage of excessive electric power consumption. In the experimental device, hot water in storage tank was used to heat the outlet pipe from the tank if the pipe surface temperature falls lower than a set point. The cold water pipe to the storage tank was installed to directly contact the hot water pipe surface temperature rose by transferred heat.

Study on Field Experiment of Stack Effect Reduction in Stairwell of Building (건축물 계단에서의 연돌효과 저감방안에 대한 현장실험 연구)

  • Kim, Jung-Yup;Kim, Ji-Seok;Lee, Su-Gak
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.27 no.9
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    • pp.484-490
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    • 2015
  • The winter stack effect that occurs in vertical construction passages such as the stairwell or elevator shaft of a high-rise building negatively affects living environments, energy usage, and personal safety; therefore, a mitigation of the stack effect is required to improve building conditions. Recently, circulation-type facilities that comprise the usage of air blowers and vertical ducts were proposed as part of a mechanical approach to quantitatively control the stack effect. In this study, these circulation-type facilities were installed in a building stairwell and the performance of the device was evaluated during its operation. A numerical-analysis result was obtained under the test conditions using a network-model-based, numerical-analysis method, and the result was then used for a comparison with the test result.

A Numerical Study on the Performance Analysis of a Solar Air Heating System with Forced Circulation Method (강제순환 방식의 공기가열식 태양열 집열기의 성능분석에 관한 수치해석 연구)

  • Park, Hyeong-Su;Kim, Chul-Ho
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.3
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    • pp.122-126
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    • 2017
  • The aim of this study was to develop a device for solving the heating problem of living space using heated air, utilizing a simple air heater type collector for solar energy. At the present time, this study assessed the possibility of a development system through theoretical calculations for the amount of available energy according to the size change of the air-heated solar energy collector. To produce and supply hot water using the heat energy of the sun, hot water at $100^{\circ}C$ or less was produced using a flat or vacuum tube type collector. The purpose of this study was to research the air heating type solar collector that utilizes heating energy with heating air above $75^{\circ}C$, by designing and manufacturing an air piping type solar collector that is a simpler type than a conventional solar collector system. The analysis results were obtained for the generated air temperature ($^{\circ}C$) and the production of air (kg/h) to determine the performance of air heating by an air-heated solar collector according to the heat transfer characteristics in the collector of the model when a specified amount of heat flux was dropped into a solar collector of a certain size using PHOENICS, which is a heat flow analysis program applying the Finite Volume Method. From the analysis result, the temperature of the air obtained was approximately $40.5^{\circ}C$, which could be heated using an air heating tube with an inner diameter of 0.1m made of aluminum in a collector with a size of $1.2m{\times}1.1m{\times}0.19m$. The production of air was approximately 161 m3/h. This device can be applied to maintain a suitable environment for human activity using the heat energy of the sun.

Indoor Air Condition Measurement and Regression Analysis System Through Sensor Measurement Device and Gated Recurrent Unit (센서 측정기와 회로형 순환 유닛(GRU)을 이용한 실내 공기 품질 측정 및 추세 예측 시스템)

  • Ahn, Jaehyun;Shin, Dongil;Kim, Kyuho;Yang, Jihoon
    • KIPS Transactions on Software and Data Engineering
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    • v.6 no.9
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    • pp.457-464
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    • 2017
  • Indoor air quality analysis is conducted to understand abnormal atmospheric phenomena and the external factor affecting indoor air quality. By recording indoor air quality measurements periodically, we are able to observe patterns in air quality. However, it difficult to predict the number of potential parameters, set parameters for a given observation and find the coefficients. Moreover, the results are time-dependent. Thus to address these issues, we introduce a microchip capable of periodically recording indoor air quality and a model that estimates atmospheric changes based on time series data.

Research on Step-Type Chemical Liquid Deodorizer using Liquid Catalyst

  • WOO, Hyun-Jin;KWON, Lee-Seung;JUNG, Min-Jae;YEO, Og-Gyu;KIM, Young-Do;KWON, Woo-Taeg
    • The Korean Journal of Food & Health Convergence
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    • v.6 no.5
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    • pp.19-25
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    • 2020
  • The purpose of this study was to research and develop a step-type chemical liquid deodorizer including a liquid catalyst that can prevent civil complaints due to odor due to its excellent deodorizing performance. The main composition of chemical liquid deodorizer including liquid catalyst is cleaning deodorization, catalyst deodorization, chemical deodorization, water film plate, deodorization water circulation device, deodorization water injection device, catalyst management system, gas-liquid separation device, chemical supply device, deodorizer control panel, etc. It consists of a device. The air flow of the step-type liquid catalyst chemical liquid deodorizer is a technology that firstly removes basic odor substances, and the liquid catalyst installed in the subsequent process stably removes sulfur compounds, which are acidic odor substances, to discharge clean air. The efficiency of treating the complex odor of the prototype was 98.5% for the first and 99.6% for the second, achieving the target of 95%. The hydrogen sulfide treatment efficiency of the prototype was 100% for the first and 99.9% for the second, which achieved 95%, which was the target of the project. As a result, ammonia was removed by the reaction of ammonia and hydrogen sulfide.

Development of Ozone Plasma Sterilizer with Air Circulation Device (공기순환장치 적용 오존 플라즈마 살균장치 개발)

  • An, June;Chun, Young-Nam
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.31 no.1
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    • pp.105-110
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    • 2021
  • Objectives: The purpose of this study was to develop a new sterilization plasma device that would be proficient at sterilizing and removing pathogenic bacteria and viruses, and applicable to air purification systems. Methods: In order to understand the performance characteristics, the discharge characteristics of a packed bed DBD reactor and the ozone reduction characteristics of an ozone filter installed at the outlet of the reactor were investigated. Results: The novel packed-bed DBD reactor was proposed, and it was confirmed that the plasma discharge was uniformly and stably discharged throughout the entire layer, and sufficient ozone was generated for sterilization. The ozone filter was tested for three methods: adsorption, adsorption-decomposition, and catalytic decomposition. When the filter thickness was 30 mm, the ozone concentrations were 0.03 ppm, 0.01 ppm, and 0.21 ppm, respectively. The adsorption and adsorption-decomposition methods satisfied the EPA standard of less than 0.05ppm, but the catalytic decomposition method did not. Conclusions: It was confirmed that the adsorption-decomposition method has relatively excellent ozone filter performance and can provide the best ozone filter.

A new correlation of the enthalpy of vaporization for pure refrigerants (순수물질 냉매에 대한 증발엔탈피의 새로운 상관식)

  • 박경근
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.10 no.4
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    • pp.449-455
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    • 1998
  • A header' is the device that makes uniform flow distribution in all branches from header of heat exchangers, pipe burner or chemical equipments. In this study, experimental tests have been performed in order to investigate the flow distribution characteristics in a straight header and tapered header which have 6 and 11 glass pipe branches. The experimental equipment consists of a water circulation system where the fluid velocity in each glass pipe is measured by Ar-ion LDV system. From the experiments and the theoretical equation, it could be recommended that tapered header should be determined so that its internal velocities inside the header become uniform according to taper of the header and number of attached branches for uniform flow distribution in energy systems.

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