• Journal of Biosystems Engineering
• /
• v.16 no.4
• /
• pp.372-383
• /
• 1991

This study was performed to find out optimum drying conditions of red pepper to minimize energy consumption and drying time, respectively, under the quality constraint using Box's complex method. The results from this study are summarized as follows. 1. From the optimization results for the drying process, energy consumption was minimized at the drying condition to minimize drying time. 2. The optimization results according to drying method was found out to be greatly affected by the quality constraint of red pepper. Especially, the turning point to change drying stage was a very important factor in the drying method with two stages.

• Journal of Biosystems Engineering
• /
• v.1 no.1
• /
• pp.55-55
• /
• 1976

An experimental work was conducted to develop an optimum operating system of various hay drying systems ; sun-drying with long hay, sun-drying after chopping, sun-drying after crushing, heated air drying after chopping using batch-type dryer and heated air drying after crushing using tunnel-type dryer. Seombody having 60 cm long and initial moisture content of approximately 79 % in wet basis was used for the experiment. The criteria selected for determining the optimum operating condition were the drying performance rate, the production cost and quality of dried matter of each drying systems. The result of this study are summarized as follows : 1. Drying characteristics of leaves of long stem hay, chopped seombody and crushed one were obtained by maintaining the oven temperature at 70 degrees centigrade. The required drying times for various samples to approximately 15% moisture content in wet basis were about 50 min .for leaves ; 160 min. for crushed hay ; 250 min. for chopped hay ; 340min. for ling hay and more than 360 min .for stems. The drying time of crushed hay was required about 50 % of that for the uncrushed long hay. Such a significant difference of drying of time between the leaf and long stem may indicate that an effective drying of seombody may not be achieved unless any kind of special process treatment for the whole hay is undertaken. 2. In each individual drying system, the following conclusions were drawn: a. After 8 days sun-drying on concrete floor under good days with average tempe?rature at $256{\circ}C$ and relative humidity at 55% at 2 P.M., the moisture content of long hay was still above 25 5'~ and the leaf loss during drying caused by wind and rough handling was more than 50 ~G. b. It was possible to dry the chopped seombody by sun-drying down to about 10 % moisture content within 5 days, however, a stock of heat and discolouration phenomena were observed during the drying, which may be due to the increased deposit-density by chopping, resulting in lowering the quality of the dried product. c. Sun-drying for the crushed material by hay-conditioner was required about 4 days to reduce the moisture content to about 10 %, keeping the quality of dried product at good grade. o. The optimum deposit-depth of the chopped seombody in the batch-type dryer used was about 28cm with about 42kg/hr of drying performance rate. However, it was necessary to overturn the materials between the upper and lower layers in order to obtain a good quality of dried product. d. The drying performance rate by the tunnel-type drier was highest among those of drying systems tested, giving the rate of approximately 400kg/day. 3. On reviewing the individual drying system for seombody, it was possible to draw conclusion that the best system was tunnel drying with the crushed seombody as far as the performance rate was concerned. However, the methods gives the highest operational cost. The system for the lowest operational cost with good quality of dried product was the sun-drying with the crushed material. Accordingly, it may be recommended that the system of sun-drying for the crushed seombody may be the most feasible system presently applicable to farm-level operation.

• Journal of Biosystems Engineering
• /
• v.1 no.1
• /
• pp.56-63
• /
• 1976

An experimental work was conducted to develop an optimum operating system of various hay drying systems ; sun-drying with long hay, sun-drying after chopping, sun-drying after crushing, heated air drying after chopping using batch-type dryer and heated air drying after crushing using tunnel-type dryer. Seombody having 60 cm long and initial moisture content of approximately 79 % in wet basis was used for the experiment. The criteria selected for determining the optimum operating condition were the drying performance rate, the production cost and quality of dried matter of each drying systems. The result of this study are summarized as follows : 1. Drying characteristics of leaves of long stem hay, chopped seombody and crushed one were obtained by maintaining the oven temperature at 70 degrees centigrade. The required drying times for various samples to approximately 15% moisture content in wet basis were about 50 min .for leaves ; 160 min. for crushed hay ; 250 min. for chopped hay ; 340min. for ling hay and more than 360 min .for stems. The drying time of crushed hay was required about 50 % of that for the uncrushed long hay. Such a significant difference of drying of time between the leaf and long stem may indicate that an effective drying of seombody may not be achieved unless any kind of special process treatment for the whole hay is undertaken. 2. In each individual drying system, the following conclusions were drawn: a. After 8 days sun-drying on concrete floor under good days with average tempe\ulcornerrature at $256{\circ}C$ and relative humidity at 55% at 2 P.M., the moisture content of long hay was still above 25 5'~ and the leaf loss during drying caused by wind and rough handling was more than 50 ~G. b. It was possible to dry the chopped seombody by sun-drying down to about 10 % moisture content within 5 days, however, a stock of heat and discolouration phenomena were observed during the drying, which may be due to the increased deposit-density by chopping, resulting in lowering the quality of the dried product. c. Sun-drying for the crushed material by hay-conditioner was required about 4 days to reduce the moisture content to about 10 %, keeping the quality of dried product at good grade. o. The optimum deposit-depth of the chopped seombody in the batch-type dryer used was about 28cm with about 42kg/hr of drying performance rate. However, it was necessary to overturn the materials between the upper and lower layers in order to obtain a good quality of dried product. d. The drying performance rate by the tunnel-type drier was highest among those of drying systems tested, giving the rate of approximately 400kg/day. 3. On reviewing the individual drying system for seombody, it was possible to draw conclusion that the best system was tunnel drying with the crushed seombody as far as the performance rate was concerned. However, the methods gives the highest operational cost. The system for the lowest operational cost with good quality of dried product was the sun-drying with the crushed material. Accordingly, it may be recommended that the system of sun-drying for the crushed seombody may be the most feasible system presently applicable to farm-level operation.

• Journal of Biosystems Engineering
• /
• v.36 no.4
• /
• pp.273-278
• /
• 2011

This study was carried out to define the optimum drying conditions for Lycium chinense Miller as a useful healthy food, because recently the cultivation area and yield of this fruit are increased. The experiments of two varieties were performed at the temperature of $45^{\circ}C$, $50^{\circ}C$, $55^{\circ}C$ and $60^{\circ}C$. The drying ratio was the slowest and quality was the best at the drying temperature of $45^{\circ}C$. The drying temperature was higher, drying ratio was more faster and the quality became worse. The difference of drying ratios between the varieties was insignificant. The energy consumption per hour was the minimum at the drying temperature of $45^{\circ}C$, but the total energy consumption was the maximum for the long drying time. Also, the energy consumption at the drying temperature $50^{\circ}C$, $55^{\circ}C$ and $60^{\circ}C$ was not very different from others. Considering the drying ratio, quality and energy consumption, the drying time of 36 hours at the drying temperature of $50^{\circ}C$ was the most optimum condition.

• Applied Biological Chemistry
• /
• v.38 no.1
• /
• pp.78-82
• /
• 1995

A microcomputer drying system, which could be designed to be operated easily and economically, was developed. The optimum drying conditions with this system for onion and ginger were obtained. The temperature, relative humidity, and weight of material were measured and controlled successfully, and the better quality of products was obtained. Optimum drying condition for onion was $65^{\circ}C$ and 25% RH, and for ginger was $50^{\circ}C$ and 25%, respectively.

• Journal of Power System Engineering
• /
• v.19 no.4
• /
• pp.43-49
• /
• 2015

This study has been analyzed and investigated the possibility for the substitution of a heat source with the application of PTC(Positive Temperature Coefficient Heater) in a food drying machine. And this experiment was conducted to measure temperatures at the upper part of the vessel and the heat sink. And the structure has the many holes plane connected with the external air in the upper part of similar volumetric vessel, and attached to the PTC heater (3sets) of total consumption electricity of 120[W] in Al radiant heat structure and the small fan (2sets) in the suitable space of the lower part. Consequently, it was found that at the most conditions of food drying test with the seven holes(5mm) under the control temperature $62^{\circ}C$, the optimum drying condition formatted and the optimum time range especially appeared from 6,500 second to 7,000 second in case of drying test on banana sample.

• Korean Journal of Medicinal Crop Science
• /
• v.18 no.1
• /
• pp.9-14
• /
• 2010

Several presowing seed treatments have been used to facilitate the seed germination and seedling emergence. The study was performed to design a model of presowing seed treatments in Taraxacum platycarpum. Germination and seedling growth responses to temperature, drying, chilling, $GA_3$ and priming were investigated to know the optimum germination conditions and presowing treatment. The optimum temperature condition for germination and seedling growth were $15{\sim}20^{\circ}C$ at dark condition. The seeds exposed to infra red light, however, did not germinate. The moisture content of seeds dried at $35^{\circ}C$ for 3.5 hours was returned to the level of unimbibed seeds. The germination of seeds dried under dark condition was better than those dried under infra red light. Prechilling treatment imposed for 6 weeks showed higher germination rate than $GA_3$ treatment or priming. In field test, the highest field emergence was observed in the seeds dried after prechilled for 6 weeks and followed by drying followed by $GA_3$ > low temperature > $KNO_3$ priming. Imbibition with 0.1 mM $GA_3$ solution for 2 hours then drying at 35 for 3.5 hour under dark condition was effective to the practical presowing treatment for Taraxacum seeds.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.11 no.6
• /
• pp.189-194
• /
• 2012

The purpose of this study is to predict the performance of a cyclone drying machine and air ejector used in drying applications. This paper deals with optimization of the geometry of the ejector for sludge drying using computational fluid dynamics. To facilitate the design of a jet ejector for air drying machines, a numerical model of simultaneous mass and heat transfers between the liquid(sludge) and gas(air) phases in the jet ejector was developed. The steady-state model was based on unidimensional balance equations of mass, energy and momentum for the liquid and gas phases. It was shown that the optimum condition to minimize pressure and momentum loss of air in the ejector was d=220mm. It was found that sludge particles inside the cyclone was smoothly discharged by the conical wedge installed on the bottom of the cyclone.

• Korean Journal of Poultry Science
• /
• v.24 no.2
• /
• pp.59-66
• /
• 1997

Optimum drying conditions to utilize porcine blood from slaughter house for blood meals, and the effects of blood meals on growth in broiler chicks were investigated. Moisture and protein con-tents of slaughter porcine blood were 79.8 and 16.4%, respectively. The protein contents of the flash dried blood meals at 80˚C were not different from those of the spray dried blood meals at 160 and 190˚C, but higher by 17% relative to those of the spray dried blood meals at 80 and 120˚C. Results from protein analysis by SDS-polyacrylamide electrophoresis showed that flash dried blood meals at 80˚C and spray dried blood meals at 160˚C were better than spray dried blood meals at 80, 120 and 190˚C in terms of protein quality. In Feeding Trial I with broiler chicks, body weights of chicks fed 2, 4 and 6% flash dried blood meal diets at 80˚C were increased at 35 days by 5.6, 7.9 and 4.0%, respectively, compared to control group(P<0.05). In Feeding Trial II, body weights of chicks fed 4 and 6% flash dried blood meal diets at 80˚C were increased at 42 days by 4.9 and 5.3%, respectively, compared to control group(P<0.05). Feed conversion ratios of chicks fed diets 4 and 6% flash dried blood meal diets at 80˚C were significantly improved at 42 days by 7.0 and 3.7%, respectively, compared to that of control group(P<0.05). The optimum drying condition of slaughter porcine blood seemed to be the flash drying method at 80˚C

• Food Science and Preservation
• /
• v.10 no.4
• /
• pp.476-481
• /
• 2003

As its high functional properties to be used as medicine or food, the cultivation of Agaricus mushroom has been expanded and iぉ commercialization required better storage methods that can extend its functional and nutritional value for longer period. We selected drying as the most plausible method to meet such requirement, and several drying conditions were investigated to locate the optimum drying condition that can be used to keep the quality of mushroom. Drying temperature of 50$^{\circ}C$, 60$^{\circ}C$, 100$^{\circ}C$ were selected to trace the drying time required to achieve the moisture content of mushrooms less than 10%. The drying temperature at 50$^{\circ}C$ required 29 hrs of drying time, while 100$^{\circ}C$ required only 10 hrs of drying tune. However, their quality characteristics on the following categories, on the degree of browning and color were investigated to find the optimum drying condition. In addition, sensory evaluation was conducted to evaluate the quality of dried mushrooms produced by each drying condition. The browning of the mushroom was evidently increased as the higher drying temperature was used and 50$^{\circ}C$ drying produced the most desirable quality of all in pileus or stipe. The aeon of browning intensified by drying temperature was comparable to the result of whiteness index value, which resulted lower L values as drying temperature increased. and the 50$^{\circ}C$ drying resulted the most highest L values among all drying samples. As the browning and whiteness results implied, the sensory evaluation result gathered from the present research indicated that the 50$^{\circ}C$ drying was the most favorable drying condition by scoring the most highest average scores on flavors, color, appearance, and overall acceptability conducted by the 10 evaluation panels.