• Title, Summary, Keyword: Drying apparatus

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Development of drying apparatus using 2-way condensation for marine products (2방식 응축을 이용한 수산물 건조 장치 개발)

  • Hwang, Jea-Ho
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.42 no.4
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    • pp.259-266
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    • 2006
  • In this study, the 2-way condensation system was designed applying air-to-air heat pump to dry a marine product such as squid in the winter. And to be made the drying apparatuses by this system, there are two kinds of type, A type, was set a compressor outside of the drying apparatus, B type, was set a compressor in the drying room. And then the variations of temperature in drying room were measured to compare the heating performance of the drying apparatuses between A type and B type at $-6.5^{\circ}C$, outdoor temperature. The temperature of the drying room for B type was increased to $36^{\circ}C$ but the temperature of the drying room for A type was not increased to $36^{\circ}C$, to be increased to $20^{\circ}C$.

DRYING CHARACTERISTINCS OF THIN-LAYERS OF WHEAT AND BARLEY AT NEAR-AMBIENT TEMPERATURE

  • Sun, Da-Wen;J.J.Woods
    • Proceedings of the Korean Society for Agricultural Machinery Conference
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    • pp.896-905
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    • 1993
  • Thin-layers of wheat and barley are dried at near-ambient temperatures(3.5$^{\circ}C$ -5$0^{\circ}C$) in order to obtain the intrinsic drying data. The well established apparatus was modified to enable it to record all the sample weight data in still air by using a purpose -built automatically controlled sliding valve. The air could be diverted in less than 0.5seconds and a 7 second period was required to attain a steady weight reading. With this apparatus, very smooth drying curves were obtained. The data of sample weight , drying temperature and dew point temperature wee recorded continuously . The drying process was terminated when the moisture content change in 24 hours was less than 0.004 d.b. This was achieved by drying a sample for about a week . The final points were recorded as the dynamic equilibrium moisture content(EMC). The drying data were than fitted to the exponential Newton model and the dynamic EMC data were fitted to the Modified-Chung-Pfost Model . All the fitted parameters are given and comparison is made with previous published data. The comparisons who that the current drying constants are lower than the previous data, the dynamic EMC data obtained for wheat and barely agree with the previous data. The results show that to obtain the drying constant in the exponential Newton model, adequate drying time is necessary.

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Construction and Application of an Automated Apparatus for Calculating the Soil-Water Characteristic Curve (자동 흙-함수특성곡선 시험장치 구축 및 활용)

  • Song, Young-Suk;Lee, Nam-Woo;Hwang, Woong-Ki;Kim, Tae-Hyung
    • The Journal of Engineering Geology
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    • v.20 no.3
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    • pp.281-295
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    • 2010
  • A new, automated apparatus is proposed for calculating the Soil-Water Characteristic Curve (SWCC), representing a simple and easily applied testing device for continuous measurements of the volumetric water content and suction of unsaturated soils. The use of this apparatus helps to avoid the errors that arise when performing experiments. Consequently, the apparatus provides greater accuracy in calculating the SWCC of unsaturated soils. The apparatus is composed of a pressure panel, flow cell, water reservoir, air bubble trap, balance, sample-preparation accessories, and measurement system, among other components. The air pressure can attain 300 kPa, and a general test can be completed in a short time. The apparatus can simply control the drying process and wetting process. The changes in volumetric water content that occur during the drying and wetting processes are shown directly in the SWRC program, in real time. As a case study, we performed an SWCC test of Joomunjin sand (75% relative density) to measure matric suction and volumetric water content during both the drying and wetting processes. The test revealed hysteresis behavior, whereby the water content on the wetting curve is always lower than that on the drying curve for a specific matric suction, during the wetting and drying processes. Based on the test results, SWCCs were estimated using the Brooks and Corey, van Genuchten, and Fredlund and Xing models. The van Genuchten model performed best for the given soil conditions, as it yielded the highest coefficient of determination.

Determination of soil water characteristic curve and permeability equation of unsaturated soils using modified triaxial apparatus (변형된 삼축시험장치를 이용한 불포화토의 함수특성곡선과 투수계수방정식의 결정)

  • Kim, Suk-Nam;Park, Chi-Won;Mok, Young-Jin
    • Proceedings of the Korean Geotechical Society Conference
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    • pp.362-369
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    • 2005
  • Studying unsaturated soil mechanics, determination of soil water characteristic curve and permeability equation is an essential factor but it is not easy. In this research a new testing apparatus was developed to determine soil water characteristic curve and permeability equation. The testing to get saturated permeability coefficients and soil water characteristic curves for two soils was performed by using the developed testing apparatus. First, a saturated permeability testing was performed and then the testing to get soil water characteristic curve of a drying process was performed. Next, the testing to get soil water characteristic curve of a wetting process was performed. Testing results showed hysteresis phenomena between soil water characteristic curve of a drying process and soil water characteristic curve of a wetting process. The permeability equations were determined by a theoretical method where a saturated permeability coefficient and a soil water characteristic curve were used.

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Drying Characteristics of Plating Sludge by Microwave (마이크로파 가열에 의한 도금슬러지 건조특성)

  • 문경환;손종렬;김덕찬
    • Journal of environmental and Sanitary engineering
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    • v.13 no.1
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    • pp.9-15
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    • 1998
  • Microwave heating and drying processes have been well established in various industrial applications. Feasibilities of successful application of microwave drying to many material have been shown on the laboratory or pilot-plant scale. The microwave drying behavior of plating sludge are considered in this paper. The plating sludge containing 70%, 80% and 90% water exposed to microwave power at 2,450 MHz, 700W. An experimental microwave drying apparatus was designed and constructed to monitor weight loss during drying. By studying the drying characteristic curve, the moisture in sludge was almost classified into two categories : free moisture and intestinal moisture. And the critical moisture contents at which the drying rate ceases to be constant were from 10.1 to 10.5%. A simple drying model is proposed which may be used to describe drying behavior of plating sludge. The constant rate and the falling rate periods in microwave drying were addressed separately. From the eqation of constant rate period the drying rate constants decreased exponentially with increasing depth. Microwave heating compared with conventional heating offered higher heating rates from 9 to 16 times. Therefore, microwave drying process can be effective in removing moisture from plating sludge.

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Heating Dryness Experiment and Characteristic of red pepper by Induction Heating apparatus (유도가열장치에 의한 고추의 가열건조 실험 및 특성)

  • Han, K.H.;Baek, J.W.;Joe, K.Y.;Baek, S.H.
    • Proceedings of the KIEE Conference
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    • pp.260-262
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    • 2002
  • The scope of applications industrial or household manufactures, is on the increase. In this study, it applies a principle of induction heating to food dryness for preservation of food. And it applies indirect heating process using overheating steam, which analyzes thermal characteristic of heating apparatus depending on its construction. It was verified that application of proposed process was appropriate by drying test of food.

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Determination of Soil Water Characteristic Curve and Permeability Equation of Unsaturated Soils Using Modified Triaxial Apparatus (변형된 삼축시험장치를 이용한 불포화토의 함수특성곡선과 투수계수방정식의 결정)

  • Kim Suk-Nam;Park Chi-Won;Mok Young-Jin;Kim Suk-Myung
    • Journal of the Korean Geotechnical Society
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    • v.21 no.5
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    • pp.59-64
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    • 2005
  • In studying unsaturated soil mechanics, determination of soil water characteristic curve and permeability equation though not easy, is an essential factor. In this research a new testing apparatus was developed to determine soil water characteristic curve and permeability equation. A test to get saturated permeability coefficients and soil water characteristic curves for two soils was performed by using the developed testing apparatus. First, a saturated permeability test was performed and then the test to get soil water characteristic curve of a drying process was performed. Next, the test to get soil water characteristic curve of a wetting process was performed. Test results showed hysteresis phenomena between soil water characteristic curve of a drying process and soil water characteristic curve of a wetting process. The permeability equations were determined by a theoretical method where a saturated permeability coefficient and a soil water characteristic curve were used.

Influencing Factors in Drying and Shrinking Characteristics of Root Vegetables (근채류의 건조 및 수축특성에 영향을 미치는 인자)

  • Cho, Duck-Jae;Hur, Jong-Wha;Kim, Hee-Yun
    • Korean Journal of Food Science and Technology
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    • v.21 no.2
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    • pp.203-211
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    • 1989
  • During hot air drying of root vegetables such as radish and sweet potatoes, shrinkage and casehardening occurred, and thereby the quality change appeared. Therfore the hot air drying apparatus in which air temperature, relative humidity and air velocity could be controlled was designed, and the drying and shrinking characteristics of radish and sweet potatoes were studied. Also the external factors that affected these characteristics were investigated. The whole drying process of radish and sweet potatoes could be divided into four different drying rate periods, namely constant rate period, first falling rate period, second falling rate period (a) and (b). The shrinking rate curve consisted of four periods nearly corresponding to drying rate periods. The shrinking rate slowly increased in the constant rate period, rapidly increased in the first falling rate period, and reached the highest value in the early period of the second falling rate period. The surface shrinkage was greatly affected by the thickness of sample, relative humidity and initial moisture content. The shrinking ratio was increased with decreasing thickness and increasing relative humidity and initial moisture content.

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A Suggested Method for Predicting Permeability of Porous Sandstone Using Porosity and Drying Rate (공극률과 건조율을 이용한 다공질 사암의 투과도 추정방법 제안)

  • Ko, Eunji;Kim, Jinhoo
    • Geophysics and Geophysical Exploration
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    • v.17 no.3
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    • pp.121-128
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    • 2014
  • As the permeability is an important parameter to characterize the ease with which a porous medium transmits fluids, it is usually obtained by fluid flow experiment using core samples. In order to measure the permeability, however, an experimental apparatus is required and it might take long measurement time, especially for tight samples. In this study, the relationship between permeability and porosity as well as drying rate has been investigated to predict the permeability without a series of measuring experiments. Porosity is measured by drying monitoring method, which measures weight variation continuously while drying surface-dried saturated sample, and drying rate is obtained from weight variation ratio with respect to the water saturation. The total of 6 Berea sandstone samples, which have a permeability range of 70 to 670 mD, were used in this work, and a new and empirical equation which could predict permeability of porous sandstone by using porosity and drying rate were obtained through regression analysis.

Comparative Study on Unsaturated Characteristic Curves of Boeun Granite Weathered Soil during Drying and Wetting Paths (건조 및 습윤과정에서 보은 화강암 풍화토의 불포화특성곡선 비교)

  • Song, Young-Suk
    • Journal of the Korean Geotechnical Society
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    • v.32 no.7
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    • pp.15-24
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    • 2016
  • To investigate the unsaturated characteristics of the Boeun granite weathered soil, matric suction and volumetric water content were measured in both drying and wetting paths using Automated Soil-Water Characteristics Curve Apparatus. Based on the measured results, Soil-Water Characteristics Curve was estimated by van Genuchten (1980) model. The relationship between effective degree of saturation and matric suction showed the non-linear curve with S-shape and the hysteresis phenomenon occurred during drying and wetting paths. Suction Stress Characteristics Curve was estimated by the Lu and Likos (2006) model. The suction stress in drying path was constantly maintained and that in wetting path tended to increase when the effective degree of saturation was low. But the suction stress in drying path was larger than that in wetting path at the same degree of saturation when the effective degree of saturation became larger. Meanwhile, Hydraulic Conductivity Function was evaluated by the van Genuchten (1980) model which is one of the parameter estimation methods. The unsaturated hydraulic conductivity decreased with increasing the matric suction, and the decreasing velocity regarding to the matric suction in drying path was larger than that in wetting path.