• 제목/요약/키워드: Pressure Recovery

검색결과 922건 처리시간 0.027초

Nylon SCY 편성물의 편성조직에 따른 외형, 신장특성 및 의복압 변화 (Appearance, stretch, and clothing pressure changes in nylon SCY knitted fabric by structure)

  • 상정선;박명자
    • 한국의상디자인학회지
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    • 제21권4호
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    • pp.17-26
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    • 2019
  • This research aims to obtain useful data on the development of compression garment products with high-stretch knitted materials. Using nylon SCY, four specimens were knitted. Then, appearance (width, length, weight, thickness), stretch property (stretch, recovery) and clothing pressure were measured and their interrelation was analyzed. In the comparison of appearance features, yarn floating caused shrinkage in both course and wale directions of the specimens. Yarn overlapping by tucking caused a release in the course direction and shrinkage in the wale direction. Also, structural change was affected by the weight and thickness change of the knitted fabric. In the analysis of fabric stretch, yarn floating reduced the extension in course direction and increased that in wale direction of the knitted fabric. However, yarn overlapping reduced the elongation in both directions. In the analysis of recovery, yarn floating and overlapping raised fabric recovery in both directions, and tuck structure was superior to float in recovery. In the analysis of clothing pressure, 'Plain-Float' structured fabrics showed a higher clothing pressure than 'Plain' and the clothing pressure value of 'Plain-Tuck' was lower than that of 'Plain'. As for the correlation between fabric appearance, stretch property, and clothing pressure, the appearance change in course direction had a major influence on the clothing pressure. The shrinkage of appearance led to a decrease in stretch and an increase in clothing pressure.

나노여과를 이용한 Sodium Lactate의 회수 (Recovery of Sodium Lactate Using Nanofiltration)

  • 이은교;강상현;장용근;장호남
    • 한국미생물·생명공학회지
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    • 제27권4호
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    • pp.320-326
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    • 1999
  • The effects of operating pressure, lactate concentration, impurities, and pH on solution flux and lactate rejection in nanofiltration were investigated with model sodium lactate solutions (lactate 10~200g/L) as a model system. In the tested range of pressure(80~140 psig), the solution flux was observed to be proportional to the operating pressure and the rejection of lactate increased only slightly with the pressure. Both of the flux and the rejection decreased with lactate concentration, while the recovery rate of lactate increased. The effects of glucose and yeast extract as impurities on lactate rejection were negligible, but the flux decreased significantly with the addition of yeast extract. At low lactate concentrations, the rejection of lactate increased with pH due to the increased repulsion (Donnan exclusion effect) between lactate ions and membrane surface. But, at high lactate concentrations, the donnan effect was observed to be overwhelmed by the effect of sodium ions added to adjust the pH, and the rejection of lactate decreased with pH. When fermentation broth containing about 89g/L of lactate was nanofiltered, the flux and the rejection of lactate were 2.8L/$m^2$h and 5%, respectively at 120psig. Both of them were slightly lower than those with model solutions. The recovery rate was 2.6mol/$m^2$h.

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역삼투 담수시스템용 에너지회수장치의 손실극복 메커니즘 설계 (Design of Loss-reduction Mechanisms for Energy Recovery Devices in Reverse-osmosis Desalination systems)

  • 함영복;김영;노종호;신석신;박종호
    • 동력기계공학회지
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    • 제16권3호
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    • pp.5-9
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    • 2012
  • Novel mechanisms for Energy Recovery Devices are proposed to diminish the pressure loss in the high-pressure reverse-osmosis system. In the beginning, the state-of-the-art in the design of Energy Recovery Devices is reviewed and the features of each model are investigated. The direct-coupled axial piston pump(APP) and axial piston motor(APM) showed 39% energy recovery at operating pressure of reverse osmosis desalination systems, 60 bar. Meanwhile, the developed PM2D model, in which APM pistons are arranged parallel to those of APP, is more compact and showed higher efficiency in a preliminary test. Loss-reduction mechanisms employing rod piston and double raw valve port are additionally proposed to enhance the efficiency and durability of the device.

지능형 포탄의 저 감속 회수장치를 이용한 포탄의 감속방법 (Deceleration Method of Munition to used Soft Recovery System for Smart Munition)

  • 김명구;조종두;이승수;유일용;장쾌현
    • 한국소음진동공학회논문집
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    • 제17권9호
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    • pp.777-784
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    • 2007
  • With the development of micro electronic circuits and optical equipment, the demand for developing smart munitions with the ability to autonomously search for and attack targets has increased. Since the electronic components within smart munitions are affected by high temperatures, pressure, and impulsive forces upon the combustion of gunpowder, stability and reliability need to be secured for them. Securing those stability and reliability requires soft recovery system which can decelerate smart munitions. A theoretical analysis of flow is performed for the secure recovery of bullets on the basis of Euler equation for compressible fluids. The inner pressure on a pressure tube, the speeds of bullets, and the deceleration of munitions are calculated theoretically. Theoretical results are compared with the data from the experiment with soft recovery system set up at the laboratory.

바이오가스로부터 고순도 CH4 회수를 위한 PSA 공정의 실험적 연구 (Experimental Study on PSA Process for High Purity CH4 Recovery from Biogas)

  • 김영준;이종규;이종연;강용태
    • 설비공학논문집
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    • 제23권4호
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    • pp.281-286
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    • 2011
  • The objective of this study is to optimize the four-bed six-step pressure swing adsorption(PSA) process for high purity $CH_4$ recovery from the biogas. The effects of P/F(purge to feed) ratio and cycle time on the process performance were evaluated. The cyclic steady-states of PSA process were reached after 12 cycles. The purity and recovery rate of product gas, pressure and temperature changes were constant as the cycle repeated. It was shown that the P/F ratio gave significant effect on the product recovery rate by increasing the amount of purge gas in purge and regeneration step. The optimal P/F ratio was found to be 0.08. As the cycle time increased, the product purity decreased by increasing the feed gas flow rate. It was found that the optimal operating conditions were P/F ratio of 0.08 and total cycle time of 1,440 seconds with the purity of 97%.

ASME Boiler & Pressure Vessel Code에 따른 배열회수보일러 기수분리기의 피로 평가 (Fatigue Evaluation of Steam Separators of Heat Recovery Steam Generators According to the ASME Boiler and Pressure Vessel Code)

  • 이부윤
    • 한국기계가공학회지
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    • 제17권4호
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    • pp.150-159
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    • 2018
  • The present research deals with a finite element analysis and fatigue evaluation of a steam separator of a high-pressure evaporator for the Heat Recovery Steam Generator (HRSG). The fatigue during the expected life of the HRSG was evaluated according to the ASME Boiler and Pressure Vessel Code Section VIII Division 2 (ASME Code). First, based on the eight transient operating conditions prescribed for the HRSG, temperature distribution of the steam separator was analyzed by a transient thermal analysis. Results of the thermal analysis were used as a thermal load for the structural analysis and used to determine the mean cycle temperature. Next, a structural analysis for the transient conditions was carried out with the thermal load, steam pressure, and nozzle load. The maximum stress location was found to be the riser nozzle bore, and hence fatigue was evaluated at that location, as per ASME Code. As a result, the cumulative usage factor was calculated as 0.00072 (much less than 1). In conclusion, the steam separator was found to be safe from fatigue failure during the expected life.

An Experimental Study on Air Leakage and Heat Transfer Characteristics of a Rotary-type Heat Recovery Ventilator

  • Han, Hwa-Taik;Kim, Min-Kyu
    • International Journal of Air-Conditioning and Refrigeration
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    • 제13권2호
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    • pp.83-88
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    • 2005
  • This study investigates the air leakage and heat transfer characteristics of a commercially available rotary-type air-to-air heat exchanger with a fiber polyester matrix. Crossover leakage between the exhaust and supply air is measured using a tracer gas method for various ventilation rates and rotational speeds of the wheel. A correlation equation for the leakage is obtained by summing up pressure leakage and carryover leakage. The pressure leakage is observed to be a function of ventilation rate only, and the carryover leakage is found to be a linear function of wheel speed. The real efficiency of the heat exchanger can be obtained from its apparent efficiency by taking into account the leakage ratio. The heat recovery efficiency decreases, as the ventilation rate increases. As the wheel speed increases, however, the efficiency increases initially but reaches a constant value for the speeds over 10rpm.

상태방정식을 이용한 주유소 탱크에서의 유증기 배출량 산정법에 관한 연구 (A Study on the Calculation Method of VOCs Emissions Using Equation of State in the Gas Station Tank)

  • 박태준;오휘성;이창언
    • 한국연소학회지
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    • 제20권4호
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    • pp.42-48
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    • 2015
  • This study was investigated the estimation of VOCs (Volatile Organic Compounds) emission from a gas station tank. To improve the atmosphere environmental quality near the gas station, the installation of vapor recovery system has been expanded recently. Therefore, it was necessary to calculate VOCs emissions from the gas station tank with vapor recovery systems for evaluation of their performance. The VOCs emissions are difficult to measure directly because of various sources and irregularly emission by pressure rise. In this study, VOCs emissions were estimated by simple calculation based on the equation of state for measured pressure, temperature and volume of a gasoline tank at a gas station. The result confirmed that the present national emission factor did not have significant discrepancy with the calculated value.

회전식 폐열회수 환기유닛의 공기누설 및 전열특성에 관한 실험적 연구 (An Experimental Study on Air Leakage and Heat Transfer Characteristics of a Rotary-type Heat Recovery Ventilator)

  • 한화택;김민규
    • 설비공학논문집
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    • 제16권12호
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    • pp.1197-1203
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    • 2004
  • This study investigates the air leakage and heat transfer characteristics of a rotary-type air-to-air heat exchanger with a fiber polyester matrix. The leakage airflow rate is measured using a tracer gas method for various ventilation rates and rotational speeds of the matrix wheel. A correlation equation for air leakage is obtained by combining the pressure leakage and the carryover leakage. The pressure leakage is observed to be a function of ventilation airflow rate only, and the carryover leakage is found to be a linear function of rotational speed. The real efficiency of the heat exchanger can be obtained from its apparent efficiencies by taking into account the air leakage ratio. As the ventilation rate increases, the heat recovery efficiency decreases. As the rotational speed of the matrix increases, the efficiency increases initially but reaches a constant value for the rotational speeds over 10 rpm.

화학레이저 압력회복을 위한 축소형 이젝터의 성능변수 (Parametric Study of Subscale Ejector for Pressure Recovery of Chemical Lasers)

  • 김세훈;김형준;권세진
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2002년도 학술대회지
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    • pp.135-138
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    • 2002
  • High-speed ejection of burnt gases from the resonator cavity is essential for performance optimization of the chemical laser system. Additionally, to maintain the population of lasing species at a level for maximum optical power, the pressure within the cavity must be of order of 10 torr. In the present study, a small-scale ejector was designed and built for parametric study of its performance. High-pressure air was used as a motive gas. Measurements include schlieren visualization and pressure distribution trace near the ejector nozzle and along the diffuser downstream of the ejector. preliminary tests showed performance of the ejector is a function of parameters including mass flow rate and stagnation pressure of the motive gas, ejector nozzle area ratio, throat area of the diffuser downstream of the ejector.

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