Analytic Study on On-Line Model of Moisture in Hot Air Drying Process of Grain

2017 ◽  
Vol 872 ◽  
pp. 360-372
Author(s):  
Zhi Wei Mai ◽  
Bi Ying Wang ◽  
Chang You Li
Keyword(s):  
Moisture Content ◽  
Cross Flow ◽  
Drying Rate ◽  
Drying Process ◽  
Counter Flow ◽  
Drying Characteristics ◽  
Concurrent Flow ◽  
Content Ratio ◽  
Real Time Tracking ◽  
Drying Technology

This study aims to review variation pattern of moisture content ratio of grains in deep-bed drying process, guide the drying technology design, realize real-time tracking and regulation in drying process, improve the quality of drying process and reduce energy consumption. Based on the moisture diffusion model in thin layer drying process, the principle of mass conservation of deep drying process, state function and irreversible thermodynamics analytic method, we have established and solved basic equations of deep-bed drying of grains, obtained the moisture content ratio of grains and analysis formula of drying velocity distribution in processes of concurrent flow drying, counter flow drying, cross-flow drying and standing drying and resolved the sustained decreasing drying process of grains in the concurrent flow drying and extreme point of drying rate in the counter-flow drying. Under the same conditions of temperature, humidity and air output, the drying velocity in counter-flow drying significantly higher than that in the concurrent flow drying. It means the energy utilization effects in counter-flow drying is better than that in the concurrent flow drying. Drying characteristics of grains in cross-flow drying and standing flow drying are the same, while drying rates in inlet-air side and outlet-air side vary widely. It means that when the layer thickness is 0.5m and the moisture content is over 20%, the drying rate in outlet-air side is nearly zero and the drying uniformity is bad. Tests on 5HP-3.5 recirculation drier shows that maximum deviation between analytic value and measured value in deep drying process is 0.69% and the range scope is -0.27%-0.69%. From the drying characteristics of grains, deviations mainly come from instrument detection deviations. The analytic method has important significance for realizing real-time tracking and regulation in drying process, guiding drying technology design, reducing energy consumption, increasing drying rate and drying machine capacity.

Exploratory evaluation of oscillation drying for thick hemlock timbers

Holzforschung ◽  
2004 ◽  
Vol 58 (4) ◽  
pp. 428-433 ◽  
Author(s):  
E. K. Sackey ◽  
S. Avramidis ◽  
L.C. Oliveira
Keyword(s):  
Moisture Content ◽  
Pacific Coast ◽  
High Amplitude ◽  
Temperature Oscillation ◽  
Drying Rate ◽  
Second Phase ◽  
Drying Process ◽  
Drying Characteristics ◽  
Low Amplitude ◽  
Total Impact

Abstract The study explores the effect of dry-bulb (Tdb ) and wet-bulb (Twb ) temperature oscillation in a conventional kiln on the drying characteristics of 105-mm-square Pacific coast hemlock. Five kiln-charges were dried using four oscillating drying schedules and a control. The base drying temperatures for the control were Twb =53°C, Tdb =60°C for the first drying phase and increased to Twb =65°C, Tdb =80°C in the second phase. These temperatures were oscillated at two amplitude and frequency combinations, namely, 3°C for 4 h (low) and 6°C for 8 h (high). The results indicated that the total impact of oscillating schedules on the drying rate was more pronounced at the early stages of the drying process. Oscillating Tdb at higher amplitudes increased drying rate by 12%, whereas the low amplitude counterpart reduced kiln residence time by 10–14%. The final moisture content variability decreased in both Twb oscillated schedules. Core and shell moisture content variation also slightly decreased in the low amplitude Twb oscillated schedules. High amplitude oscillated Tdb also showed 5% less casehardening than the control, whilst its low amplitude counterpart increased. The low amplitude Twb oscillated schedule had the least surface checks and splits.

scholarly journals Mathematical Modelling of the Drying Characteristics of Milled Sorghum Residue

2021 ◽  
pp. 1-17
Author(s):  
J. Isa ◽  
O. I. Majasan ◽  
K. A. Jimoh
Keyword(s):  
Moisture Content ◽  
Initial Moisture Content ◽  
Moisture Diffusivity ◽  
Effective Moisture Diffusivity ◽  
Drying Rate ◽  
Drying Process ◽  
Air Velocity ◽  
Drying Characteristics ◽  
Effective Moisture ◽  
Drying Behaviour

During milling of cereal grains, bran which is separated from the starchy endosperm of the grain is a major by-product. In this study, milled sorghum residue was dried in a cabinet dryer under different conditions (temperature and air velocity). The obtained drying data were fitted into ten existing mathematical models and obtained the best model while, the effective moisture diffusivity and activation energy of the drying process was determined using Arrhenius type approach. The result shows that the initial moisture content obtained for the sorghum residue using standard oven drying method were 41.28 ± 0.33%, 49.52 ± 0.63 % and 47.06 ± 0.42 % on wet basis for the wet residue of variety A, B and C, respectively, at equilibrium point, the final moisture content of about 12.93 ± 0.14 – 14.31± 0.07 as temperature ranges from 40 oC to 70 oC and air velocity ranges from 0.8 m/s to 1.2 m/s. During the drying process, the drying rate falls more rapidly as it was initially high as a result of more moisture in the sorghum residue and the drying rate decreases slowly until reaching the reduced moisture content. The obtained values of effective moisture diffusivity (Deff) ranges between 9.89 x 10-10 and 22.21 x 10-10 m2/s, 9.45 x 10-10 and 20.62 x 10-10 m2/s and 8.56 x 10-10 and 20.76 x 10-10 m2/s for variety A, B and C, respectively. However, the result of the modelling shows that the drying characteristics of variety A and B of the sorghum residue can be predicted using Midilli et al. model while the drying behaviour of Variety C can be predicted using Hii et al. model.

scholarly journals EFEK PERLAKUAN LOW TEMPERATURE LONG TIME BLANCHING TERHADAP KARAKTERISTIK CABAI KERING

Agrika ◽  
2020 ◽  
Vol 14 (2) ◽  
pp. 140
Author(s):  
Nunik Lestari ◽  
Ratnawaty Fadilah ◽  
Andi Muhammad Akram Mukhlis ◽  
Samsuar Samsuar
Keyword(s):  
Low Temperature ◽  
Vitamin C ◽  
Moisture Content ◽  
Drying Rate ◽  
Drying Process ◽  
Direct Sunlight ◽  
Drying Characteristics ◽  
Long Time ◽  
Positive Effect

ABSTRAKProses pretreatment sebelum cabai dikeringkan berperan penting untuk menghasilkan cabai kering dengan kualitas lebih baik. Penelitian ini bertujuan untuk melihat efek pretreatment LTLT blanching sebelum proses pengeringan terhadap karakteristik pengeringan dan kualitas cabai kering. Penelitian dilaksanakan dengan 12 perlakuan, yaitu pengeringan dengan pretreatment LTLT blanching pada suhu 60, 70, dan 80 oC masing-masing selama 10, 15, dan 20 menit, lalu pengeringan dengan pretreatment HTST blanching pada suhu 100 oC selama 10 detik, pengeringan tanpa pretreatment blanching di dalam alat pengering ERK, serta pengeringan tanpa pretreatment blanching di bawah sinar matahari secara langsung. Hasil penelitian menunjukkan pengaruh positif pretreatment LTLT blanching dapat mempercepat laju pengeringan, menghasilkan cabai kering dengan kadar air rendah sesuai standar SNI, menghasilkan warna cabai kering yang menarik, serta memiliki kandungan vitamin C lebih tinggi dibanding cabai kering tanpa pretreatment blanching. Secara keseluruhan, perlakuan pretreatment LTLT blanching pada suhu 80 oC selama 20 menit adalah perlakuan terbaik dari penelitian ini dengan kadar air akhir 8.17%, laju pengeringan yang tercepat, kandungan vitamin C sebesar 0.96%, dan warna yang menarik. ABSTRACTThe pretreatment before drying chilies plays an important role to produce better quality of dried chilies. This study aims to determine the pretreatment effect of LTLT blanching before the drying process on the drying characteristics and quality of dried chilies. This research was carried out with 12 treatments, namely drying with LTLT blanching pretreatment at 60, 70, and 80 oC for 10, 15, and 20 minutes respectively, then drying with HTST blanching pretreatment at 100 oC for 10 seconds, drying without pretreatment blanching in the ERK dryer, and drying without pretreatment blanching in direct sunlight. The results show the positive effect of LTLT blanching pretreatment which can accelerate the drying rate, produce dry chilies with low water content according to SNI standards, produce an attractive dried chilies color, and have a higher vitamin C than dried chilies without blanching pretreatment. Overall, pretreatment with LTLT blanching at 80 oC for 20 minutes is the best treatment in this study with a final moisture content of 8.17%, the fastest drying rate, a vitamin C content of 0.96%, and an attractive color. 

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.

Study on Drying Characteristics of Microalgae under Different Conditions

2013 ◽  
Vol 724-725 ◽  
pp. 296-299
Author(s):  
Chun Xiang Chen ◽  
Xiao Qian Ma ◽  
Xiao Cong Li ◽  
Wei Ping Qin
Keyword(s):  
Moisture Content ◽  
Mass Loss ◽  
Fresh Water ◽  
Chlorella Vulgaris ◽  
Drying Process ◽  
Drying Time ◽  
Drying Characteristics ◽  
Second Stage ◽  
Drying System ◽  
Two Stages

To find out an alternative of coal saving, a kind of microalgae, Chlorella vulgaris (C. vulgaris) which is widespread in fresh water was studied by digital blast drying system. The effect of the moisture content, drying thickness and temperature on the drying process of C. vulgaris were investigated. The results indicated that when the drying temperature is high, the moisture content is low and the material thickness is small, the drying time is short. The drying process of C.vulgaris can be divided into two stages, and the mass loss is mainly occurred in the second stage . The results will provide guidance for design of drying process and dryer of microalgae.

Drying technology of mesquite pods (Prosopis laevigata) and microstructural insights

2020 ◽  
Vol 122 (9) ◽  
pp. 2953-2963
Author(s):  
Sadoth Sandoval Torres ◽  
Daniel Lopez Cravioto ◽  
Juan Rodríguez Ramírez ◽  
Lilia L. Méndez Lagunas ◽  
Luis Gerardo Barriada Bernal ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Moisture Content ◽  
Food Industry ◽  
Characteristic Curve ◽  
Drying Process ◽  
Sem Images ◽  
Content Type ◽  
Milling Operation ◽  
Drying Technology ◽  
First Time

PurposeMesquite pods offer a high nutritional content; A flour can be produced from them; nevertheless, the moisture content makes the milling process difficult. Then, before the milling operation a drying process must be implemented, but drying technology must be studied in order to characterise the process and identify the effect of drying temperature on the magnitude of drying rate.Design/methodology/approachProsopis Laevigata pods were collected in Oaxaca (Southern of Mexico) and they were dried. Three stages of maturity were identified and pods in the stage three of maturity were dried by forced convection. The internal structure of the pods was analyzed by scanning electron microscopy (SEM). The pods were dried in a tunnel dryer at 40, 50, 60 and 70° C, 10% relative humidity and air velocity of 2.6 m/s. From experimental data, a lumped analysis was conducted for drying.FindingsWe found that the internal microstructure of this material is a limiting factor for moisture migration. In order to reduce the moisture content in the pods, a minimum air temperature of 60° C must be applied. The characteristic drying curve shows a good agreement with the experimental drying kinetics. The nutritional composition (carbohydrates, sugar and protein) of pods reveals important applications for the food industry.Practical implicationsThe mesquite pods are important ethnic foods. In order to obtain flour, the drying of pods is mandatory. Drying must be applied in stage three of maturity which can be identified based on color changes and moisture content. The moisture content affects the performance of milling operation, then a minimum drying temperature of 60° C and low relative humidity must be applied. SEM images show the complex microstructure of the pods which hinders the moisture diffusion. The drying characteristic curve was deduced for the first time; it helps to understand the drying behavior of pods. The chemical composition of mesquite pods reveals interesting applications for the food industry. The methodology for drying is useful for researchers and producers.Originality/valueMezquite pods is an interesting ethnic food for people with celiac disease. This is the first time a research paper describes the drying process at detail. The SEM images, the convective drying operation and the characteristic curve are presented for the first time. The information will be useful for the industry and academia.

scholarly journals Influence of Different Hot Air Drying Temperatures on Drying Kinetics, Shrinkage, and Colour of Persimmon Slices

Foods ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 101 ◽  
Author(s):  
Senadeera ◽  
Adiletta ◽  
Önal ◽  
Di Matteo ◽  
Russo
Keyword(s):  
Moisture Content ◽  
Quadratic Model ◽  
Drying Process ◽  
Air Velocity ◽  
Hot Air Drying ◽  
Drying Time ◽  
Air Drying ◽  
Drying Characteristics ◽  
Drying Temperature ◽  
Hot Air

Drying characteristics of persimmon, cv. “Rojo Brillante”, slabs were experimentally determined in a hot air convective drier at drying temperatures of 45, 50, 55, 60, and 65 °C at a fixed air velocity of 2.3 m/s. It was observed that the drying temperature affected the drying time, shrinkage, and colour. Four empirical mathematical models namely, Enderson and Pabis, Page, Logarithmic, and Two term, were evaluated in order to deeply understand the drying process (moisture ratio). The Page model described the best representation of the experimental drying data at all investigated temperatures (45, 50, 55, 60, 65 °C). According to the evaluation of the shrinkage models, the Quadratic model provided the best representation of the volumetric shrinkage of persimmons as a function of moisture content. Overall, higher drying temperature (65 °C) improved the colour retention of dried persimmon slabs.

scholarly journals Experimental Study on Super-Heated Steam Drying of Lignite

2011 ◽  
Vol 347-353 ◽  
pp. 3077-3082 ◽  
Author(s):  
Yong Chun Shi ◽  
Jie Li ◽  
Xuan You Li ◽  
Jing Wu ◽  
Mao Gang Wu ◽  
...  
Keyword(s):  
Power Plants ◽  
Experimental System ◽  
Drying Rate ◽  
Drying Process ◽  
Operation Conditions ◽  
Hot Air ◽  
Application Potential ◽  
Drying Technology ◽  
Two Stages ◽  
Steam Drying

This paper applies super-heated steam drying technology to improve the quality of lignite. A unique experimental system was built up. In order to obtain the optimum operation conditions, the drying kinetics was measured. The temperature range of super-heated steam was from 120 to 200°C. The results showed that the drying process of super-heated steam drying of lignite can be well depicted by two stages, as a constant drying rate stage followed by a falling drying rate stage. The comparison of drying process to the hot air drying showed the superior advantages of super-heated steam drying on safety, drying capacity and energy conservation. Analysis shows the huge application potential of lignite in power plants by means of the super-heated steam drying.

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.

scholarly journals Mathematical Model for Solar Drying of Grains

2019 ◽  
pp. 1-18
Author(s):  
A. O. Fagunwa ◽  
O. A. Aregbesola ◽  
M. O. Faborode
Keyword(s):  
Mathematical Model ◽  
Thermal Properties ◽  
Moisture Content ◽  
Climatic Conditions ◽  
Drying Rate ◽  
Solar Drying ◽  
Drying Process ◽  
Complex Procedure ◽  
Unique Method ◽  
Complex Phenomena

Mathematical modeling of drying process is a complex procedure that should be carefully done. Moreso, model for solar drying, which is a unique method of drying due to constant fluctuation in the climatic conditions, requires complete integration of the complex phenomena that are involved for accurate prediction of moisture content and drying rate. A mathematical model was developed from heat and mass balance equation considering the physical and thermal properties of the grain, meteorological factors and convective heat transfer during solar drying of grains. The data obtained from the model was compared with experimental results obtained using a solar dryer to dry five selected grains – cowpea, soyabean, groundnut, maize and sorghum at airflow rates of 0.22 m/s, 0.76 m/s and 0.94 m/s. The results from statistical analysis and regression analyses used to compare the results showed that the model is adequate in predicting the moisture content and drying rate of the selected grains as well as other agricultural products with closer physical and thermal properties.

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