• Journal of Ginseng Research
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• v.33 no.4
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• pp.361-366
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• 2009

This research aims to develop a new drying technology using super-heated steam to reduce the time required for drying ginseng and to enhance its quality. The drying rate of ginseng powder treated with hot-air drying after drying with super-heated steam was about 40% faster than the drying rate of ginseng powder treated with hot-air drying. Minimal difference was found between hot-air drying and hot-air drying after drying with super-heated steam in the general composition of the ginseng powder, such as its crude lipid, crude protein, crude fiber, and ash. Moreover, no difference was found between hot-air drying and hot-air drying after drying with super-heated steam in terms of the ginseng powder's mineral and free sugar contents. The crude saponin contents was 5.43% in the ginseng treated with hot-air drying and 5.4% in the ginseng treated with hot-air drying after drying with super-heated steam. The ginseng powder that was treated with hot-air drying after drying with super-heated steam had a slightly higher redness compared to the ginseng powder that was treated with hot-air drying alone. The number of microorganisms of the ginseng powder treated with hotair drying after drying with super-heated steam showed a reduction of one log cycle in the total bacteria and two log cycles in the yeast molds compared to the ginseng powder treated with hot-air drying alone.

• Korean Chemical Engineering Research
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• v.46 no.2
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• pp.258-273
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• 2008

For being recent high oil price age, the interest in superheated steam drying technology is increasing as the method to enhance the energy efficiency of drying process consuming a lot of energy. This technology uses the superheated steam as drying medium to dry the materials and has advantages that can save the energy by recycling the evaporated high-temperature steam, enhance the quality of dried products, and minimize the exhaust of environmental pollution materials. In this work, it has been introduced from general drying principle to the principle and related studies of drying technology using superheated steam, using examples of superheated steam with dryer types, and industrial applications.

• Journal of Korean Society of Water and Wastewater
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• v.38 no.3
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• pp.155-164
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• 2024

There are two primary sludge drying methods such as the direct heating microwave method and the indirect heating steam one. In this study, the drying treatment facility at sewage treatment plant A applied both of these drying methods. The research aimed to investigate the optimal operation approach for the drying facility, considering the input sludge and the moisture content data after the drying process. Moisture content and removal rate data were executed at the research facility from January 2016 to December 2018. First, the microwave, a direct heating drying method, performed intensive drying only on the outer surface of the sludge by directly applying heat to the sludge using far infrared rays, so effective sludge drying was not achieved. On the other hand, the steam method of the indirect heating method used steam from a gas boiler to maximize the utilization of the heat transfer area and reduce energy of the dryer, resulting in an effective sludge drying efficiency. The sludge moisture content brought into the sludge drying facility was about 80%, but the moisture content of the sludge that went through the drying facility was less than 10% of the design standard. Therefore, the steam method of the indirect heating method is more effective than the microwave method of the previous direct heating method and is more effective for maintenance It has proven that it is an efficient method of operating construction facilities.

• Journal of the Korean Wood Science and Technology
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• v.48 no.2
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• pp.121-135
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• 2020

This study aims to evaluate applicability for the continuous drying process using saturated and superheated steam for large-square timber. During drying of the boxed heart square timber, changes in moisture content were examined through the slices of the surface, inner and core layers. The results showed that there was a large moisture content difference between the surface and inner layers during saturated steam drying and between the inner and core layers during superheated steam drying. However, despite the moisture content difference between the layers, no surface check occurred, and an internal check occurred only near the pith or juvenile parts of the wood. The maximum value of the drying stress of the dried larch boxed heart square timber, calculated from the elastic strain of the slice and the tangential elastic modulus of the larch, was 1.30 MPa. The tangential tensile strength of the larch was estimated at 5.21 MPa under temperature and moisture content conditions when drying stress was at a maximum. That is, in the continuous drying process, the saturated and superheated steam did not generate a check in the surface because the drying stress of the wood did not exceed the tangential tensile strength. In further studies, the superheated steam drying conditions will need to be relaxed to suppress the occurrence of internal checks. Such studies would make the continuous drying process using saturated and superheated steam available for the drying of large-square timber.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.3
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• pp.412-417
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• 2015

This study was carried out to investigate the effect of steam-drying method on physicochemical properties and antioxidant activities of Alliun hookeri root (AHR). Moisture, crude protein, crude fat, and crude ash contents of raw and steam-dried AHRs were 10.91~14.15%, 11.14~13.49%, 0.83~3.02%, and 7.55~8.98%, respectively. Sulfur contents of steam-dried AHRs were 2.0 and 2.2 times lower than that of raw AHR (0.51%), respectively. pH and total sugar contents of AHRs were reduced by steam-drying, whereas titrate acidity and browning intensity were increased. The L and b values of AHRs in Hunter's value were also reduced, but a value was increased by steam-drying. Among hot water extracts from raw and steam-dried AHRs, four times steam-drying showed the lowest $EC_{50}$ values (0.44, 9.01, and 0.48 mg/mL, respectively) in DPPH radical assay, ABTS radical assay, and reducing power, whereas four times steam-drying had the highest total phenolic content ($34.47{\mu}g/mg$) and browning intensity (2.05 and 0.20 at 280 and 420 nm, respectively). The antioxidant activities of hot water extracts from raw and steam-dried AHRs were closely correlated with their total phenolic contents and browning intensity, showing coefficient of determination ($R^2$) values higher than 0.87. From the results, we suggest that steam-drying method could be used as an effective process for increasing the antioxidant activity of AHR.

• Clean Technology
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• v.12 no.4
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• pp.217-223
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• 2006

The operating variables of a desorption step were experimentally investigated tor the cycle of the process made up of benzene adsorption, steam desorption, and drying step. The effect of adsorbent regeneration depending on existence and nonexistence of drying step was studied by breakthrough curves obtained in the adsorption step of the second cycle. The duration of drying step was determined by the experimental results. In case that the amount of nitrogen gas was fixed, the regeneration efficiency increased with the amount of steam. However, the effect of steam decreased as the amount of nitrogen increased. Therefore, it would be possible to predict the optimum amount of steam comparing the amount of nitrogen gas with amount of steam in economic view.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.12
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• pp.1725-1731
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• 2016

This study was carried out to investigate the effects of steam-drying on antioxidant compounds and antioxidant activity of Alliun hookeri root (AHR). The yield of methanolic extracts, total phenolic content (TPC), browning intensity (280 nm and 420 nm), and organosulfur compound contents (alliin and cycloalliin) in raw and steam-dried AHRs were 10.71~37.40%, $15.53{\sim}36.36{\mu}g/mg$, 0.48~2.09, 0.01~0.25, $1.46{\sim}700.61{\mu}g/mg$, and $1,173.95{\sim}2,182.60{\mu}g/mg$, respectively. Yield, TPC, and browning intensity of AHRs increased by steam-drying, whereas organosulfur compound contents decreased. Of all methanolic extracts from raw and steam-dried AHRs, four-time steam-drying showed the lowest $EC_{50}$ values (0.43, 7.53, 0.34, and 0.48 mg/mL, respectively) for DPPH radical scavenging activity, ABTS radical scavenging activity, SOD-like activity, and reducing power, whereas four-time steam-drying resulted in the highest TPC ($36.36{\mu}g/mg$) and browning intensity (2.09 and 0.25 at 280 and 420 nm, respectively). The antioxidant activities of methanolic extracts from raw and steam-dried AHRs were closely correlated with their TPC, browning intensity, and organosulfur compound content, showing correlation determination coefficient ($R^2$) values higher than 0.82. As a result, four-time steam-drying of AHRs could be useful as potential antioxidant sources.

• Korean Journal of Food Science and Technology
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• v.29 no.2
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• pp.292-301
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• 1997

In drying process, to minimize the quality degradation by improved drying process and pretreatment methods, carrots, cabbages and radishes were dried and rehydrated. Physico-chemical properties of product were analyzed to determine the optimum pretreatment method and drying models were applied to explain drying mechanisms. Microwave, steam and water were used prior to drying as blanching method. In consideration of physical properties, optimum treatment time was decided that microwave was 1 min, steam and water were each 10 min. Control, steam, water, microwave and osmotic dehydration were treated prior to drying as pretreatment individually, osmotic dehydration was lower than the other treatmemt in drying efficiency, but carotene content was higher than the others. The effect continued after rehydration. Ten panelists tested dried and rehydrated carrots. After rehydration, the quality of air dried product with osmotic dehydration was superior to freeze dried without treatment. The fittness of drying models were conducted in order to explain the mechanism of drying each process. Quadratic model was most fittable to explain during drying. However, in rehydration process, no fittable model was found.

• Journal of the Korean Society of Tobacco Science
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• v.17 no.1
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• pp.68-78
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• 1995

A study of expanding tobacco includes the steps of adjusting the moisture content of cut tobacco, without the use of exogenous impregnants by contacting the filler with a high velocity gaseous medium at elevated temperature such that heat is rapidly and substantially uniformly transferred from the medium to the filler for a total contact time sufficient to expand the tobacco leaves. Study is disclosed for drying and expanding cut tobacco by introducing the tobacco into an elongated tubular shaped conduit through which steam high temperature 150-35$0^{\circ}C$ and high velocity above the 18m1sec, super steam is recycled. moisture content of shreded tobacco leaves, immediately before treatment within the range of from 10% to 24% and, most preferably, within the range of from 18% to 21%. Expanding rate showed 70% in NC -82(B.3) and 42% in Burley -21(B.1) which is produced in 1993 under this condition. When expanding tobacco expanded tobacco did not change significally, but they were decreased at 27$0^{\circ}C$ very largely. The curtailment of cost price and physical and chemical properties of various items were improved in cigarettes. Key words : Expanding tobacco, Super steam tobacco expansion, Fast drying tobacco, High temperature treat tobacco, Puffing tobacco.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.5
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• pp.1058-1063
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• 1999

The purpose of this study was to investigate the differences in proximate composition, free sugars, organic acids, fatty acids, amino acids, mineral components, hunter color values and calory values between freeze dried and steam dried Gastrodia elata Blume. Crude fat and crude fiber decreased during manu facture of steam dried Gastrodia elata Blume. The contents of sugars in steam dried Gastrodia elata Blume decreased during manufacture than that of freeze dried Gastrodia elata Blume. The contents of malic acid, oxalic acid, ketoglutaric acid, malonic acid and succinic acid in freeze dried were similar to those in steam dried Gastrodia elata Blume. Citric acid decreased in steam dried Gastrodia elata Blume. The contents of linoleic acid, palmitic acid and oleic acid in freeze dried were similar to those in steam dried Gastrodia elata Blume. The contents of free amino acids in steam dried Gastrodia elata Blume decreased during manufacture. The mineral component contents of the Gastrodia elata Blume were greater in the order of Mn