• Title/Summary/Keyword: Drying Characteristics

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A Study on the Thermal Characteristics of Low Temperature Vacuum Drying by Hot Water Temperature (가열수 온도에 의한 저온진공건조 열적 특성에 관한 연구)

  • 김경근;최순열
    • Journal of Advanced Marine Engineering and Technology
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    • v.25 no.3
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    • pp.588-594
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    • 2001
  • The aim of this paper is to develop the low temperature vacuum dryer, with low initial investments and operating costs, easy operating method and trouble-free operation Usally operations just below atmospheric pressure, as with direct dryers, but some are built for vacuum operation with pressure as low 50 mmHg abs. The lowers the boiling point to $39^{\circ}C$ The experimental data of quantitative analysis for using practically were obtained by the constant drying rate period and reducing drying rate period according to the temperature of hot water which is the experimental parameters of present experiment. As the results, it took about 20 hours for material to reach about 18% of the final moisture content is order to store products for a long time about 450% of the early moisture content at the beginning of drying and maximum drying rate comes to about 0.30 kg/m2hr at about 350% of the moisture content.

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Artificial Neural Network Models in Prediction of the Moisture Content of a Spray Drying Process

  • Taylan, Osman;Haydar, Ali
    • Journal of the Korean Ceramic Society
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    • v.41 no.5
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    • pp.353-358
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    • 2004
  • Spray drying is a unique drying process for powder production. Spray dried product must be free-flowing in order to fill the pressing dies rapidly, especially in the ceramic production. The important powder characteristics are; the particle size distribu-tion and moisture content of the finished product that can be estimated and adjusted by the spray dryer operation, within limits, through regulation of atomizer and drying conditions. In order to estimate the moisture content of the resultant dried product, we modeled the control system of the drying process using two different Artificial Neural Network (ANN) approaches, namely the Back-Propagation Multiplayer Perceptron (BPMLP) algorithm and the Radial Basis Function (RBF) network. It was found out that the performance of both of the artificial neural network models were quite significant and the total testing error for the 100 data was 0.8 and 0.7 for the BPMLP algorithm and the RBF network respectively.

An Experimental Study on the Properties of Drying Shrinkage for Alkali-Activated Slag Mortar (알칼리 자극제를 혼입한 고로슬래그 모르타르의 건조수축 특성에 관한 실험적 연구)

  • Chun Jung-Hwan;Kim Jae-Hun;Jee Nam-Yong
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2006.05a
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    • pp.97-100
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    • 2006
  • This paper report the result of the investigation on the properties of drying shrinkage for alkali-activated slag mortar in different relative humidity Commonly we know that drying shrinkage means lost more moisture but the mechanism of drying shrinkage of alkali activated slag mortar is not entirely due to the quantity of weight loss of water from mortar. pore size distribution and the calcium silicate hydrate gel characteristics have a critical influence on the magnitude of drying shringkage to alkali activated slag mortar. For this investigation, Ca(OH)2, Na2SiO4 were as alkali activator with 5 dosages(6%, 9%, 12%, 15%, 20%) and curing condition were three different relative humidity(35%, 65%, 95%) at $20{\pm}3^{\circ}C$

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Operation of microcomputer aided convective drying system (마이크로컴퓨터 제어 열풍건조장치의 제작운영)

  • Jeong, Sin-Gyo;Gang, Jun-Su;Choe, Jong-Uk
    • Food Science and Preservation
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    • v.1 no.2
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    • pp.99-105
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    • 1994
  • To convert the analog signal from the drying process into the digital signal, the interface circuit was designed and built. To measure the weight and temperature during drying process, strain gauge type load cell and temperature transducer composed of pt 100 $\Omega$ thermometers and wheatstone bridge circuits were built and used. The temperature control device was composed of photocoupler and triac. Microcomputer aided experimental convective drying system was built with above cricuits and devices. Drying characteristics of onions can be estimated using this system.

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Drying characteristics and physical properties of medicinal and edible mushrooms (약용버섯과 식용버섯의 건조방법에 따른 품질특성)

  • Kim, Bo-Min;Jung, Eun-sun;Aan, Yong-hyun;Hwang, In-Wook;Chung, Shin-Kyo
    • Food Science and Preservation
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    • v.23 no.5
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    • pp.689-695
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    • 2016
  • In this study, the drying characteristics of medicinal (Ganoderma lucidum, Phellinus linteus) and edible (Pleurotus eryngii, Lentinus edodes) mushrooms were investigated. Their shrinkage ratios, Hunter's color values, and rehydration ratios were evaluated. Mushrooms were cut with rectangular (1 cm) and square ($1{\times}1cm$) shapes, and dried in the room temperature and at $50^{\circ}C$ and $70^{\circ}C$ using hot-air dryer. Initial moisture contents of edible mushrooms were higher than those of medicinal mushrooms, whereas final moisture contents were vice versa. Drying rate was the highest when drying at $70^{\circ}C$ (p<0.05). Moreover the drying rate of square slices was higher than that of rectangular slices (p<0.05). The shrinkage ratios of both medicinal mushrooms and edible mushrooms were the least when drying at $50^{\circ}C$ and $70^{\circ}C$, respectively (p<0.05). The changes of color values were less in the medicinal mushrooms dried in the room temperature than in the hot-air dried medicinal mushrooms (p<0.05). However, in case of edible mushrooms, the changes of color values were less in the hot-air dried mushrooms (p<0.05). Rehydration ratios of medicinal mushrooms dried at $50^{\circ}C$ was the highest (p<0.05). In contrast, rehydration ratios of edible mushrooms was the highest when drying in the room temperature (p<0.05). Thus, the hot-air drying at $50^{\circ}C$ would be suggested as the efficient drying method for both medicinal mushrooms and edible mushrooms.

Quality Characteristics of Ginseng Treated by Hot Air Drying after Being Dried using Super-heated Steam (초급속 과열증기를 이용한 인삼의 품질 특성)

  • Kim, Kyung-Tack;Hong, Hee-Do;Kim, Sung-Soo
    • 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.