• Journal of the Korean Society of Food Science and Nutrition
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• v.18 no.1
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• pp.29-33
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• 1989

As one of the application of microcomputer for data acquisition and temperature control of food drying process, these studies designed and built 'the interface system, measuring sensors of weight and temperature, temperature control system'. The basic and assembly language was used to operating these system. These system measured successfully the variables such as weight and temperature during food drying, and controlled Automatically the drying temperature.

• Korean Journal of Food Science and Technology
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• v.11 no.4
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• pp.258-263
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• 1979

A cylindrical focusing solar food dryer made with aluminum-laminated acryl film was demonstrated for the dehydration of agricultural product and its perfomance was analyzed with respect to the solar energy utilization and its scale-up technology. With one square meter reflector and a 74 cm copper pipe absorber, the heat exchange efficiency between air stream and absorber was 1.39 %. The installation of circular segment-baffle increased 33 % of the efficiency. In dehydration of radish-cut with this drier, 58 % of fuel consumption was saved. The relationship between reflector area and heat energy utilization was established for the scale-up purpose.

• Proceedings of the KIEE Conference
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• 2006.10a
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• pp.184-185
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• 2006

환경오염 등으로 최근 자주 발생하는 국지성 집중호우로 인해 건물 중에서 지하 변전실은 가장 먼저 침수가 발생하게 된다. 따라서 본 논문은 지하에 시설된 전기 설비 중 몰드 변압기의 표면이 수분과 같은 불순물에 의해 오염될 경우 절연물에 미치는 영향과 위험성을 알아보기 위한 것으로 건조 시와 수용액 분무 후에 대한 연면손상에 대해 연구하였다. 실험 장치는 고전압 발생장치, 전극, 촬영장치 등으로 구성되었으며, 실험 결과 불꽃의 형상은 건조 시에는 가늘고 강한 빛으로 거의 직선적이고, 수용액 분 후는 산발적으로 광범위하게 나타난다. 방전에 의한 연면손상 특성을 보면 건조 시와 수용액 분무 후 모두 전극 간격이 증가할수록 탄화의 흔적이나 손상의 정도가 감소함을 알 수 있었으며 전반적으로 수용액 분무 후는 건조 시 보다 탄화 및 손상의 정도가 낮은 반면 부위는 광범위한 것으로 나타났다.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2010.04a
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• pp.173-173
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• 2010

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2010.04a
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• pp.174-174
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• 2010

• Korean Journal of Food Science and Technology
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• v.19 no.6
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• pp.550-555
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• 1987

Strain gauges attached on the Bourdon tube and load cell were used as the sensors for measuring the vacuum pressure in drying chamber and the weight loss of Shiitake mushrooms respectively. The vacuum drying system was interfaced further with the Bear II microcomputer. The interface devices used were built with such IC chips as MC 6821, ADC 0809, SN 74244 and SN 7424. The relationship between readings of vacuum gauge (P, mmHg) and digital outputs (D) from the microcomputer was represented by P =3.08 D-13.4875(r=0.9999). The weights of drying sample (W) were also related with the digital outputs (D) by W=0.4076 D-6.4762 (r=0.9999). During the vacuum drying of Shiitake mushrooms. the data on pressure and weight were recorded at regular intervals using an acquisition program on the microcomputer system. The Page model was fitted well to the drying data of Shiitake mushrooms. resulting in the following empirical equations : $(M-M_e)/(M_o-M_e)=\exp(-0.1569t^{1.0048})$ at 400 mm Hg up to 14 hours and $(M-M_e)/(M_o-M_e)=\exp(-0.1385_t^{1.2688})$ at 600 mm Hg up to 8 hours.

• Journal of the Korea Organic Resources Recycling Association
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• v.16 no.2
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• pp.47-56
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• 2008

The objective of this research is to evaluate the optimum recycling methods for the sewage sludge cakes at different microwave power-settings and for different periods of time. The dehydrated sewage sludge cakes used in this study was obtained from N wastewater treatment plan in the P City. The beginning drying processes were carried out in a microwave oven with 2,450 MHz frequency and power ranges of 1kW to 4 kW. The continuous conveyer drying system was also operated with 2,450 MHz frequency and power setting, ranging from of 1 kW to 6 kW. Initial moisture content of the sewage cake is 78~80%, and the moisture content decreased rapidly up to 0.2~2(wt%) within short periods due to breaking the cell walls. This study is also conducted to evaluate the characteristics of sewage sludge cakes with respect to important physical parameters effect on the thermal kinetics for evaporation water in the sludge which are operation times, moisture contents, drying rates, input amounts, flow rates and calorific values. It takes 60 minutes and 120 minutes to reach the critical moisture contents with power setting of 4 kW for 3kg/min and 6kg/min of the flow rates respectively. It takes 120 minutes and 110 minutes to reach the critical moisture contents with flow rates of 2.5 cm/min and sludge input of 6kg/min for the power settings of 4 kW and 6 kW respectively. The most effective value of the power for drying the sludge is 4 kW. Operation with 6kg/min and 4kW on 2cm of the sludge thickness can be effectively and inexpensively to reach the critical moisture contents, when you compare 2cm of the sludge thickness with 1cm and 3cm of the sludge thickness.

• Journal of the KSME
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• v.35 no.9
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• pp.829-835
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• 1995

통상의 열교환기에서 전열면이 제거된 형태의 직접열교환을 통하여 제작비나 열전달 특성에 큰 효과를 얻을 수도 있어 에너지이용 합리화에 기여하는 특성과 사례를 언급하였다. 또한 통상의 열교환기 설계와 다른 매질간의 공유계면에서 발생 가능한 전달특성을 위주로 설계상의 일부 유의사항을 기술하였다. 직접열교환의 기술축적은 상변화를 동반하는 열전달(two phase heat transfer) 문제의 기초지식은 물론, 염수플랜트(desalination)의 기본 요소설계, 원자로의 냉각계 통사고(LOCD)대책, 기타 냉각탑, 탱크가열, 증발기(evaporator), 건조장치(drier), 각종 기계, 화공 공정장치 설계 등 매우 광범위한 기술파급 효과도 기대할 수 있으므로 관련 기술자들의 많은 관심을 기대한다.

• Bulletin of the Society of Naval Architects of Korea
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• v.41 no.1
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• pp.33-47
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• 2004

조선기자재는 선박의 건조 및 수리에 사용되는 모든 기계와 자재류를 일컫는 것으로, 선종과 규모에 따라 다소 차이가 있으나 약460여종에 이르며 선박 건조원가의 55∼65%를 차지하고 있다. 선박부품인 조선기자재는 기능별로 나누어 금속제품, 화학제품, 용접재료, 주단제품으로 구성되는 선체부, 엔진을 포함하는 추진장치와 보조기계로 대별되는 기관부, 조타, 계선, 하역, 안전장비 및 거주설비 등의 의장부 및 동력, 배선, 조명, 항해통신, 제어장치 등으로 구성되는 전기ㆍ전자부로 분류된다. 특히 최근에는 방화ㆍ방재 설비로 대표되는 안전설비를 의장부에서 별도로 분류하기도 하며, 선박의 자동화 추세에 따라 전기와 전자부분을 분리하여 분류하기도 한다.(중략)

• The Journal of Engineering Geology
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• v.20 no.3
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• pp.281-295
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• 2010

A new, automated apparatus is proposed for calculating the Soil-Water Characteristic Curve (SWCC), representing a simple and easily applied testing device for continuous measurements of the volumetric water content and suction of unsaturated soils. The use of this apparatus helps to avoid the errors that arise when performing experiments. Consequently, the apparatus provides greater accuracy in calculating the SWCC of unsaturated soils. The apparatus is composed of a pressure panel, flow cell, water reservoir, air bubble trap, balance, sample-preparation accessories, and measurement system, among other components. The air pressure can attain 300 kPa, and a general test can be completed in a short time. The apparatus can simply control the drying process and wetting process. The changes in volumetric water content that occur during the drying and wetting processes are shown directly in the SWRC program, in real time. As a case study, we performed an SWCC test of Joomunjin sand (75% relative density) to measure matric suction and volumetric water content during both the drying and wetting processes. The test revealed hysteresis behavior, whereby the water content on the wetting curve is always lower than that on the drying curve for a specific matric suction, during the wetting and drying processes. Based on the test results, SWCCs were estimated using the Brooks and Corey, van Genuchten, and Fredlund and Xing models. The van Genuchten model performed best for the given soil conditions, as it yielded the highest coefficient of determination.