Influence of Soil Suction and Environmental Factors on Drying Characteristics of Granular Subgrade Soils

2000 ◽  
Vol 1714 (1) ◽  
pp. 98-106
Author(s):  
W. Virgil Ping ◽  
Ching-Chin Ling ◽  
Robert K. H. Ho
Keyword(s):  
Relative Humidity ◽  
Water Evaporation ◽  
Granular Soils ◽  
Drying Rate ◽  
Soil Drying ◽  
Soil Suction ◽  
Direct Effects ◽  
Drying Characteristics ◽  
Subgrade Soils ◽  
Excessive Water

According to contractors in Florida, construction problems have emerged because pavement soils hold excessive water and are difficult to dry and compact. Recent research on the effects of soil suction and environmental conditions on drying rate characteristics of six types of troublesome granular soils is presented. Two types of tests were conducted for the study: soil suction tests using the thermocouple psy-chrometer method and drying rate tests using an environmental chamber. The experimental results showed that both the soil suction and relative humidity had direct effects on the soil-drying rate. The drying rate decreased with an increase in soil suction for each soil type and also decreased with an increase in the percentage of fines. The influence of relative humidity on the soil-drying rate was much more significant than the effect of the temperature. The rate of water evaporation was extremely low for the soils with a higher percentage of fines when the relative humidity was high. The A-2-4 soils with greater than 20 percent of fines may have such a low drying rate in an environment with high relative humidity that they are difficult to handle during construction.

CATFISH DRYING (Clarias Batraclus) USING ‘TEKO BERSAYAP’ SOLAR DRYER

2012 ◽  
Vol 2 (1) ◽  
pp. 14-20
Author(s):  
Yuwana Yuwana
Keyword(s):  
Relative Humidity ◽  
Moisture Content ◽  
Ambient Temperature ◽  
Drying Rate ◽  
Drying Process ◽  
Drying Time ◽  
Ambient Relative Humidity ◽  
Solar Dryer

Experiment on catfish drying employing ‘Teko Bersayap’ solar dryer was conducted. The result of the experiment indicated that the dryer was able to increase ambient temperature up to 44% and decrease ambient relative humidity up to 103%. Fish drying process followed equations : KAu = 74,94 e-0,03t for unsplitted fish and KAb = 79,25 e-0,09t for splitted fish, where KAu = moisture content of unsplitted fish (%), KAb = moisture content of splitted fish (%), t = drying time. Drying of unsplitted fish finished in 43.995 hours while drying of split fish completed in 15.29 hours. Splitting the fish increased 2,877 times drying rate.

The Potential Migrated Mechanism of Water-Soluble Components in Pellets Prepared by Wet Extrusion/Spheronization: Effect of Drying Rate

2020 ◽  
Vol 17 ◽  
Author(s):  
Bingwei Wang ◽  
Jianping Liu ◽  
Zhenghua Li ◽  
Yulong Xia ◽  
Shuangshuang Zhang ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Water Soluble ◽  
In Vitro Dissolution ◽  
Drying Rate ◽  
Scanning Calorimetry ◽  
Drying Temperature ◽  
Wet Extrusion ◽  
Extrusion Spheronization ◽  
Soluble Components

Background: At present, there were numerous researches on the migration of components in tablets and granules, the investigation in the pharmaceutical literatrue concerning the effect of drying rate on the migration of water-soluble components of pellets was limited. Temperature and relative humidity (RH) were crucial parameters during the drying process which was an essential step in the preparation of pellets via wet extrusion/spheronization. To quantify these variables, the water loss percentage of pellets per minute was defined as drying rate. Objective: The study aimed to investigate the influence of drying rate on the migration of water-soluble components in wet pellets and the potential migrated mechanism. Methods: The pellets containing tartrazine as a water-soluble model drug and microcrystalline cellulose as a matrix former were prepared by extrusion/spheronization and dried at four different drying temperature and relative humidity. Afterward, the extent of migrated tartrazine was assessed regarding appearance, in-vitro dissolution test, Differential Scanning Calorimetry, X-Ray Powder Diffraction, Attenuated total reflectance Fourier transform infrared spectroscopy and Confocal Raman Mapping. Results: Results demonstrated that red spots of tartrazine appeared on the surface of pellets and more than 40% tartrazine were burst released within 5 minutes when pellets dried at 60℃/RH 10%. While pellets dried at 40℃/RH 80%, none of these aforementioned phenomena was observed. Conclusion: In conclusion, the faster drying rate was, the more tartrazine migrated to the exterior of pellets. Adjusting drying temperature and relative humidity appropriately could inhibit the migration of water-soluble components within wet extrusion/spheronization pellets.

Effect of Pre-Treatment on the Drying Characteristics and Kinetics of Okra (Abelmoschus esculetus (L.) Moench) Slices

2009 ◽  
Vol 5 (2) ◽  
Author(s):  
Olajide Sobukola
Keyword(s):  
Air Temperature ◽  
Sample Thickness ◽  
Hot Water ◽  
Drying Rate ◽  
Diffusivity Coefficient ◽  
Drying Characteristics ◽  
Rate Period ◽  
Pretreatment Conditions ◽  
Air Dryer ◽  
Kinetics Of

The effects of air temperature (50, 60 and 70°C), sample thickness (2, 4 and 6mm) and pretreatment conditions (hot water blanching, 1 and 3% sodium metabisulphite solutions) on the drying characteristics and kinetics of okra were investigated using a convective hot air dryer at a flow rate of 1.5m/s. It was observed that pretreatment conditions, sample thickness and drying air temperature significantly (P<0.05) affected drying rate. Drying rate increases as temperature of drying air increases from 50 to 70°C. The drying curve for all experiments occurred in the falling rate period with no constant rate period. Three thin layer drying models (Page, modified Page I and Wang and Singh) were evaluated using coefficient of determination (R2), root mean square error (RMSE) and the reduced chi square (?2). The three models can appropriately describe the drying kinetics of okra slices considering the different experimental conditions. The effective diffusivity was determined using the Fick’s model and was observed to vary between 1.125x10-8 – 9.93x10-9m2/s and 1.165x10-8 – 7.131x10-9 m2/s for treated and untreated samples. The Arrhenius-type relationship describes the temperature dependence of diffusivity coefficient and was determined to be 16.749kJ/mol and 22.437kJ/mol for treated and untreated samples respectively.

Constant Power Drying Rate Tester: Measurement of Water Evaporation from Textiles with Heat

2018 ◽  
Vol 19 (10) ◽  
pp. 2208-2217 ◽  
Author(s):  
Kam-Hong Chau ◽  
Ka-Po Maggie Tang ◽  
Nga-Fong Lam ◽  
Chi-Wai Kan
Keyword(s):  
Water Evaporation ◽  
Drying Rate ◽  
Constant Power

Drying of Rough Rice in Oven: An Experimental Study

2015 ◽  
Vol 365 ◽  
pp. 77-81 ◽  
Author(s):  
J.V. Silva ◽  
E.M.A. Pereira ◽  
T.H.F. Andrade ◽  
Antônio Gilson Barbosa de Lima
Keyword(s):  
Experimental Study ◽  
Relative Humidity ◽  
Moisture Content ◽  
Product Quality ◽  
Air Temperature ◽  
Drying Rate ◽  
Rough Rice ◽  
Drying Conditions ◽  
Kinetics Of ◽  
Mechanical Movement

This paper aims to present an experimental study of rough rice (BRSMG CONAI cultivar) drying by using a stationary method. The grain was dried in an oven with air mechanical movement under controlled conditions of velocity, temperature and relative humidity. In order to obtain balanced moisture content, the samples studied were kept at 40 and 70°C. Results of the drying and heating kinetics of the grain during the process are shown and analyzed. It was found that higher drying rate and lower time for drying as higher air temperature (70°C) is used. It can be concluded that the reduction of the moisture content of the grain, is considered very complex and, depending on the method and drying conditions, can substantially provokes breaking and cracks, which reduces final product quality.

The thin-layer drying characteristics of sewage sludge by the appropriate foaming pretreatment

2014 ◽  
Vol 69 (9) ◽  
pp. 1859-1866 ◽  
Author(s):  
Hui-Ling Wang ◽  
Zhao-Hui Yang ◽  
Jing Huang ◽  
Li-Ke Wang ◽  
Cheng-Liu Gou ◽  
...  
Keyword(s):  
Sample Thickness ◽  
Coefficient Of Determination ◽  
Drying Rate ◽  
Drying Time ◽  
Drying Characteristics ◽  
Thin Layer Drying ◽  
Dewatered Sludge ◽  
Drying Curves ◽  
Sludge Drying ◽  
The Impact

As dewatered sludge is highly viscous and sticky, the combination of foaming pretreatment and drying process seems to be an alternative method to improve the drying performance of dewatered sludge. In this study, CaO addition followed by mechanical whipping was employed for foaming the dewatered sludge. It was found that the foams were stable and the diameters of bubbles mainly ranged from 0.1 to 0.3 mm. The drying experiments were carried out in a drying oven in the convective mode. The results indicated that foamed sludge at 0.70 g/cm3 had the best drying performance at each level of temperature, which could save 35–45% drying time to reach 20% moisture content compared with the non-foamed sludge. The drying rate of foamed sludge at 0.70 g/cm3 was improved with the increasing of drying temperature. The impact of sample thickness on drying rate was not obvious when the sample thickness increased from 2 to 8 mm. Different mathematical models were used for the simulation of foamed sludge drying curves. The Wang and Singh model represented the drying characteristics better than other models with coefficient of determination values over 0.99.

Temperature Effects on Soil Suction for Compacted Clay Soils

2013 ◽  
Vol 723 ◽  
pp. 527-534
Author(s):  
Shu Rong Yang ◽  
Wei Hsing Huang ◽  
Shao Hung Chung
Keyword(s):  
Water Content ◽  
Clayey Soil ◽  
Expansive Soils ◽  
Soil Suction ◽  
Compacted Clay ◽  
Subgrade Soils ◽  
Thermocouple Psychrometer ◽  
Effects Of Temperature ◽  
Paper Method ◽  
Water Contents

An investigation was conducted to determine the effects of temperature, compaction water content, and compaction efforts on soil suction of two expansive subgrade soils. For this purpose, two expansive soils were statically compacted at target water contents ranging from 5% to 20%. This made it possible to explore a broad spectrum of compaction conditions. Filter paper method and thermocouple psychrometer were used to measure soil suction at temperatures ranging from 10°C to 60°C. Experimental results show that compaction water content, compaction effort, and temperature have influences on soil suction. As water content increases, the influences of compaction effort and temperature on suction become less significant. Finally multiple regression formulations for predicting the soil suction of as-compacted clayey soil were established.

Drying Characteristics of Graininess Agar under Infrared Ray and its Kinetics Model

2013 ◽  
Vol 663 ◽  
pp. 291-296
Author(s):  
Lei Yang ◽  
Qian Qian Ouyang ◽  
Si Dong Li
Keyword(s):  
High Efficiency ◽  
Linear Regression Analysis ◽  
Drying Rate ◽  
Analysis Program ◽  
Drying Method ◽  
Drying Characteristics ◽  
Low Energy Consumption ◽  
Different Temperatures ◽  
Drying Models ◽  
Drying Rates

In order to look for a low-energy–consumption and high-efficiency drying method, the drying characteristics of agar under infrared ray were studied. The results show that temperature has more obvious influence than granularity on the drying rate of agar. With the increase of temperature, the drying rate increases. The agar granularity does not have a significant influence on the drying rate. Comparisons of different drying models at different temperatures were made through linear regression analysis program. The results show that the drying procedure of agar under infrared ray can accurately be described by the Page model, and the drying rates and moisture contents at different drying stages can also be easily estimated with it.

Study on Microwave Drying Process and Drying Characteristics of Sewage Sludge

2013 ◽  
Vol 838-841 ◽  
pp. 2643-2647
Author(s):  
Jin Ping Li ◽  
Meng Yao Li ◽  
Wen Yao ◽  
Ni Wang
Keyword(s):  
Energy Consumption ◽  
Sewage Sludge ◽  
Lower Energy ◽  
Microwave Drying ◽  
Drying Rate ◽  
Municipal Sludge ◽  
Drying Process ◽  
Drying Characteristics ◽  
Pretreatment Time ◽  
Short Time

Combination of oven and microwave and only oven are two ways to study municipal sludge,and it investigates whether different size, microwave drying pretreatment, pretreatment time and oven temperature characteristics have effect on drying characteristics. The results shows that: using microwave to dry sludge need short time, the drying rate is fast, combination of oven and microwave has higher drying rate and lower energy consumption than only oven.

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