• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.9
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• pp.3827-3834
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• 2012

Recently, instead of hot air type dryers that require a lot of heat, energy-efficient heat pump dryers have been used in various fields such as paper, textile, wood, food, etc. In this paper, the characteristics of heat pump cycle were theoretically evaluated with hot-gas bypass system to further improve the energy efficiency by minimizing the use of electric heaters in early warm-up stage of the dryers for frozen agricultural products. In addition, damper system that leads outside air to flow into the dryer were optimized to obtain extra heat for higher energy efficiency.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.28 no.10
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• pp.408-413
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• 2016

The objective of this study is to investigate the performance of a heat recovery heat pump dryer using a R245fa refrigerant experimentally. In this study, the main components of the heat pump dryer were an evaporator, a compressor, a condenser, and an expansion valve. As a result, when the amount of refrigerant varied from 15 kg to 16 kg, the hot air outlet temperature in the condenser and the heat transfer rate were almost kept constant. Therefore, the amount of refrigerant at 16 kg was considered to be a suitable amount in the heat pump. As the air inlet velocity varied from 0.5 m/s to 1.5 m/s, the highest temperature in the condenser could be obtained when the air inlet velocity was 0.5 m/s. The heat transfer rate, system (COP), and hot air outlet temperature were 5.6 kW, 3.4, and $102.5^{\circ}C$, respectively, when the bypass ratio and water temperature were 0% and $60^{\circ}C$.

• International Journal of Industrial Entomology and Biomaterials
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• v.35 no.1
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• pp.45-50
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• 2017

Using the relatively low-cost, far-infrared dryer inhibiting the destruction of a variety of physiologically active components of the mulberry fruit, we have studied to make semidry mulberry fruit that can be kept at room temperature for a long time. By adjusting the temperature of the far-infrared dryer step-by-step, we developed a semi-dry method of maintaining the shape of the mulberry fruit. In addition, by drying the coating of honey after removing the juice generated by the mulberry fruit thawing process improved the acceptability of the taste of fruit. We conducted heat treatment mulberry fruit into a $95^{\circ}C$ infrared dryer 5 hours to thaw the frozen mulberry fruit. After 10 to 20% of honey coating, the primary drying ($95^{\circ}C$, 5 hours) was implemented. then, the secondary drying was conducted after controlling the temperature of the far infrared dryer $60^{\circ}C$, for 10 hours. These manufacture process was able to obtain semi-dried mulberry fruit. Dry weight ratio and moisture content were around 25%, and around 16% level respectively. It was to enable long-term storage at room temperature. Therefore, it is suggested that the method of using the far-infrared drying machine to manufacture semi-dried mulberry fruit can be a way to improve the farm income if applied to the farm.

• Journal of the Korean Solar Energy Society
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• v.24 no.1
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• pp.21-27
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• 2004

Near Infrared Ray (NIR) are primarily of interest to the high energy physicist. It is the intermediate portion of the spectrum, which extends from approximately 0.8 to 1.5 ${\mu}m$ and include a portion of the all of infrared, that is thermal radiation and is pertinent to heat transfer. It is important to study that temperature distribution of the drying materials by surface encompasses a range of NIR wave lengths. This study is to investigate the characteristics of NIR dryer by experimental results. it was made a comparison with various textiles, velocity ratio and distance of lamp and textiles. In case of spongy type textile the drying performance is the superior of all. The 0.15m distance drying effect of improvement 30% more than 0.26m distance between lamp and textiles. As the contained water increases, the drying speed for textile can be increased.

• International Journal of Industrial Entomology and Biomaterials
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• v.37 no.2
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• pp.63-68
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• 2018

Semi-dried mulberry fruit can be distributed at room temperature and maintained its chewy texture and shape. It can be used for its own itself or food materials. We develop the honey coating semi-dried mulberry fruit manufacturing method through hot air dryer. After extracting the moisture from the thawing process, honey was coated and dried. Drying time for semidried mulberry fruit was shortened by manufacturing on the day of work without going through aging process. The first the mulberry fruit juice was separated from the frozen mulberry fruit at room temperature of the laboratory or in the dryer of $60{\sim}90^{\circ}C$, then the first dried by a hot air drier at $60^{\circ}C$ for 3 to 4 h. Next, it is coated with honey, which is equivalent to 20% weight of the first dried mulberry fruit, and then the second dried at a temperature of $38^{\circ}C$ for 20 ~ 30 h. The honey coating semi-dried mulberry fruit by above method was shiny on the surface and retained its shape. The moisture content was about 15% and it was confirmed that it could be stored at room temperature.

• Journal of Korea Society of Industrial Information Systems
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• v.29 no.1
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• pp.107-116
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• 2024

Copper Filter Dryer (CFD) are responsible for removing impurities from the circulation of refrigerant in refrigeration and cooling systems to maintain clean refrigerant, and defects in CFD can lead to product defects such as leakage and reduced lifespan in refrigeration and cooling systems, making quality assurance essential. In the quality inspection stage, human inspection and defect judgment methods are traditionally used, but these methods are subjective and inaccurate. In this paper, YOLOv7 object detection algorithm was used to detect defects occurring during the CFD Shaft pipe and welding process to replace the existing quality inspection, and the detection performance of F1-Score 0.954 and 0.895 was confirmed. In addition, the cause of defects occurring during the welding process was analyzed by analyzing the sensor data corresponding to the Timestamp of the defect image. This paper proposes a method for manufacturing quality assurance and improvement by detecting defects that occur during CFD process and analyzing their causes.

• Journal of the Korean Society of Safety
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• v.18 no.2
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• pp.16-21
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• 2003

The object of this research is to prevent the industrial accidents which frequently occurred in breaking the coating in cement silo. Research was conducted to identify the cause of the coating formation, and the model experiment of aeration system was done to investigate the effect of moisture air on the coating formation. The results show that dehumidification of supply air in aeration system is the most important factor to suppress the coating formation, and the refrigerated low pressure air dryer applicable to the aeration system of cement silo was newly designed and developed. When this air dryer is applied to the cement silo, 88% of the moisture component of supply air can be reduced. Therefore the cleaning cycle extends over twice, and it contributes to the decrease of industrial accidents and cleaning cost.

• International Journal of Industrial Entomology and Biomaterials
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• v.42 no.1
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• pp.14-20
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• 2021

Mulberry was dried with low temperature vacuum dryer using microwave. The nutritional compositions of microwave-dried mulberry including proximate composition, sugar content, mineral content, total phenolic, flavonoids, and anthocyanin, beta-carotene, vitamin C, and amino acid composition were measured. Sugar contents of mulberry were 42.6 mg/100g (Cheongilppong) and 43.27 mg/100g dw (Gwasang No. 2). The main components of mulberry sugars were fructose and glucose. Mineral analysis showed that K, P, Ca, and Mg were abundant regardless of mulberry cultivars.

• Applied Chemistry for Engineering
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• v.18 no.6
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• pp.575-579
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• 2007

Sludge disposal technology has been studied with many researchers since disposal of sewage sludge has been a social problem. The current technologies include incineration, carbonization, pyrolysis, landfilling and fertilization. However, all of these processes require a dry process, because sewage sludge with more than 80% high water content is difficult to be used as a raw material. This study has the purpose to establish the optimal operation conditions and the technology as changing the variables: kiln residence time, sludge load, dryer temperature, by using the previous study that is rotary kiln type dryer designed as a numerical simulation study. As the results, optimum conditions are determined as follows: kiln residence time, sludge load, dryer temperature are $62.5kg/m^3{\cdot}hr$, 26.2 min, $330^{\circ}C$, respectively. Content of water, drying efficiency, weight loss, volume loss show that the results are $10{\pm}2$, 88, 80, 60%, and the dried sludge is released by a dryer below 10 mm.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.27 no.1
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• pp.8-13
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• 2015

The objective of this paper is to provide design data of fin-tube heat exchanger which have a large diameter oval tube for dryer application. In this study, the heat transfer and pressure drop performance characteristics of the fin-tube heat exchanger were compared with Dittus-Boelter and a new correlation equation using Wilson plot method. The simulation results based on section by section method were compared with experimental results. These results showed that a new correlation equation using Wilson plot method provided better prediction, about 3 to 12%, than the Dittus-Boelter equation, from the experiment comparison. Also, the pressure drop of simulation results showed much more deviation with the experimental results.