• Food Science and Preservation
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• v.7 no.4
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• pp.389-394
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• 2000

To utilize deteriorated sweet persimmon(Diospyros kaki T.) effectively, this study was investigated about the effective (Dying method of the powder. Chemical components, minerals, fatty acids and amino acids of hot-air dried and freeze dried conditions were determined Sample conditions used on analysis as follow; pretreatments of hot-air dry and freeze dry were soft, soft+peel, mixer, mixer+peel. The contents of crude protein, crude lipid, crude ash of hot-air dry were 0.9-1.1%,15.0-39.0% and 2.3-3.3%, respectively. And those of freeze dry were 1.3-2.2%, 27.-49.0% and 2.5%, respectively. Potassium, magnesium, phosphorus, calcium and sodium content in hot-air dry and freeze dry were high. Other minerals were less than 3.00ppm in all conditions. The major fatty acid contents were detected capric acid(C$\^$10:0/), lauric acid(C$\_$l2:0)/, tridecanoic acid(C$\_$13:00/), palmitic acid(C$\_$l6:00/), palmitoleic acid(C$\_$l6:1/), oleic acid(C$\_$18:1), linoleic acid(C$\_$18:2/), linolenic acid(C$\_$18:3/). The essential amino acids such as aspartic acid, threonine, serine, glutamic acid, glycine, alanine, valine, methirmine, isoleucine, leucine, tryosine, phenylalanine, histidine, lysine, arginine in freeze dry were contained richly. On the basis of chemical analysis, hot-air dry method will have to supply the additional different method, because simple hot-air dry method was shorten the dry time but had many problems. Therefore, the effective drying method considering changed color and nutrition was shown freeze dry method.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2008.10a
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• pp.26-29
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• 2008

Recently, the hydroforming of high strength aluminum tubes has many studies and applications in manufacturing industry, especially in automotive industry. But high strength aluminum tube has limited expansion capability at most 15% at normal temperature. New manufacturing process, called hot air forming, is introduced to apply aluminum tube to the automotive sub frame components which have complex shape and require high expansion ratio about 40%. The process is carried out at the elevated temperature above $500^{\circ}C$, so numerous material properties and process parameters related to high temperature should be investigated and determined to get a sound product. In this paper, the hot air forming process of automotive sub frame was investigated. The effect of the forming parameters such as the temperature of tool, axial feeding and gas pressure are analyzes by using explicit finite element method.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.21 no.2
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• pp.285-293
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• 1997

Numerical calculations has been performed for the flow and heat transfer to a circular cylinder from a hot circular impinging air jet. The characteristics of the flow and heat transfer are investigated and compared with the two-dimensional flow. The present study lays emphasis on the investigation on the flow and heat transfer of the three-dimensionality. The effects of the buoyancy force and the size of jet are also studied. The noticeable difference between the three and the two-dimensional cases is that there is axial flow of low temperature into the center-plane of the cylinder from the outside in the recirculation region. Local Nusselt number over the cylinder surface has higher value for the large jet as compared with that of the small jet since the energy loss of hot jet to the ambient air decreases with increase of the jet size. As buoyancy force increases the flow accelerates so that the period of cooling by the ambient air is reduced, which results in higher local Nusselt number over the surface.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.10 no.6
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• pp.784-794
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• 1998

The present study has been directed at developing thermal models to investigate the dynamic behavior of a solar cooling system including an absorption chiller, solar collectors, a hot water storage tank, a fan coil unit, and the air-conditioned space. The operation of the system was simulated for 8 hours in two different operation modes. In the mode 1, the system operated without any capacity control.0 the mode 2, an auxiliary boiler supplied heat to the generator if hot water temperature became lower than a certain value. Moreover, the mass flow rate of hot water to the generator was controlled by comparing the instantaneous room air temperature with the design value. The variation of temperature and concentration in the system components and that of heat transfer rates in the system were obtained for both modes of operation. It was found that the room temperature was maintained near the desired value in the mode 2 by supplying auxiliary heat or controlling the mass flow rate of hot water, while the deviation of room temperature was quite great in the mode 2.

• Journal of Advanced Marine Engineering and Technology
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• v.28 no.4
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• pp.618-623
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• 2004

This paper has dealt with the heat storage characteristics of gel type micro size latent heat storage material slurry. The heat release operation to the gel type micro size latent heat storage material slurry was carried out using hot air bubbles by direct contact heat exchange. This experiment was carried out using phase change material of n-paraffin so the heat release amount is higher than cold water system. The parameters of this experiment were concentration of latent heat phase change material, height of heat release bath and inlet velocity of hot air. The main results obtained are as follows : (1) The effect of concentration of latent heat phase change material dispersed with water is very affective to the direct contact heat exchange between hot air and gel type micro size latent heat storage material slurry. (2) It is clarified that the most effective concentration of latent heat phase change material dispersed with water exists around 20mass% at this type of direct heat exchange model experiment.

• Food Science and Biotechnology
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• v.15 no.1
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• pp.57-62
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• 2006

Six organophosphorus, one organochlorine, and three synthetic pyrethroid pesticides were analyzed for their residues during washing and hot-air drying of red peppers conducted in the production of powder. The residue ratio in organophosphorus pesticides was 33% in chlorpyrifos, 31 % in diazinon, 50% in methidathion, 80% in EPN, 28% in fenitrothion, and 60% in profenofos. The ratio in pyrethroids was 109% in cypermethrin, 102% in deltamethrin, and 106% in fenvalerate. That in organochlorine was 56% in ${\alpha}$-endosulfan and 90% in ${\beta}$-endosulfan. The results were greatly different between organophosphorus and pyrethroid pesticides. UV irradiation along with hot-air drying brought about a remarkable reduction of the residues, up to 70% as compared with hot-air drying only. The removal effect was most remarkable in pyrethroids, which are hardly removed by hot-air drying. The color of the pepper was not changed during UV irradiation. The use of oxidizing agents such as hydrogen peroxide or chlorine dioxide during washing did not show a remarkable removal of residues. The residue ratio was not affected whether the pesticide is contaminated artificially or naturally.

• Journal of the Semiconductor & Display Technology
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• v.9 no.2
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• pp.73-78
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• 2010

This research is about the drying and curing characteristic of conductivity metallic ink on-line curing device in order to improve the curing time for productivity in RFID Gravure printing. The curing process is carried out to increase the electric conductivity after the metallic ink is printed on the substrate. The metal ink is composed of nano-sized silver or copper particles. In this research, the combined IR and Hot air curing system is used and its results is compared with those of oven, IR and Hot Air type respectively. Generally the curing time in the past is about 3 minutes. But the combined system (IR+Hot Air) in this research shows that curing time is less than 30 seconds. These results is much faster than those of other system. This study can be help to make Roll-to-Roll drying and curing process for mass and continuous production on-line.

• 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 the Korean Society for Geothermal and Hydrothermal Energy
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• v.14 no.4
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• pp.7-12
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• 2018

Energy performance of electric heater and geothermal source heat pump type hot air dryers are compared in this study. For set temperatures of $30^{\circ}C$, $35^{\circ}C$ and $40^{\circ}C$, radish is dried from initial mass 60 kg until it gets 5 kg, where the difference equals the amount of water removed. As set temperature is increased, drying time is shortened for both electric heater and heat pump types, however energy efficiency is decreased due to increasing electricity consumption. Moisture extraction rate(MER) of electric heater is 2.58~2.84 kg/h, and for heat pump type 2.56~2.71 kg/h, showing little difference between the two types. Specific moisture extraction rate (SMER) of electric heater is 0.94~0.96 kg/kWh, and for heat pump type 1.72~2.21 kg/kWh. SMER of heat pump type is greater by 0.78~1.25 kg/kWh than the electric heater hot air dryer, which is 1.8~2.3 times better in terms of energy efficiency.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.3524-3528
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• 2007

In this study, the Peltier effect was applied to eliminate moistures in the air enclosed by a cabinet. We have developed the new electronic dehumidifier which has a new function of automatically evaporating the condensed water inner cabinet into the outside air. To obtain this function, the processes of dehumidification is that it condensed the moistures on the cold side heat sink and drained it into the hot side heat sink by the both gravitational and capillary forces and the droplets on the hot side heat sink surface was evaporated into the air outside the cabinet by the heat conducted through the hot side heat sink surface and the forced heat convection through the fan for cooling hot side heat sink. Compared to existing electronic dehumidifiers, this manufactured one showed a good performance that the electric power consumption for the same dehumidifying quantity was reduced by 50% compared with that of existing ones.