scholarly journals Study of the behavior of a multistage dryer provided with downcomer

2018 ◽  
Author(s):  
Mario Vizcarra Mendoza ◽  
Luis Verduzco Mora ◽  
Carlos Martínez Vera
Keyword(s):  
Moisture Content ◽  
Fluidized Bed ◽  
Silica Gel ◽  
Coming Out ◽  
Residence Times ◽  
Fluidized Bed Dryer ◽  
Multi Stage ◽  
In Series ◽  
Kinetics Of ◽  
Gel Drying

We study the behavior of a multi-stage fluidized bed dryer operated continuously with dowcomers. With the kinetics of silica gel drying depending on the mass of solids in the dryer and the gas feeding temperature, E = 14.5 KJ/mol, and the distribution of residence times of solids through the dryer, modeling by N tanks agitated in series, the experimental moisture content of the solids coming out of the dryer is compared with the predicted by the Vanecek model. Keywords: fluidization; gel of sílice; continuous multistage dryer.  

scholarly journals Performance Analysis of Solar Assisted Fluidized Bed Dryer Integrated Biomass Furnace with and without Heat Pump for Drying of Paddy

2016 ◽  
Vol 2016 ◽  
pp. 1-17 ◽  
Author(s):  
M. Yahya
Keyword(s):  
Moisture Content ◽  
Fluidized Bed ◽  
Heat Pump ◽  
Specific Energy Consumption ◽  
Drying Rate ◽  
Fluidized Bed Dryer ◽  
Moisture Extraction ◽  
Rate Period ◽  
Drying Behaviour ◽  
Kinetics Of

The performances of a solar assisted fluidized bed dryer integrated biomass furnace (SA-FBDIBF) and a solar assisted heat pump fluidized bed dryer integrated biomass furnace (SAHP-FBDIBF) for drying of paddy have been evaluated, and also drying kinetics of paddy were determined. The SA-FBDIBF and the SAHP-FBDIBF were used to dry paddy from 11 kg with moisture content of 32.85% db to moisture content of 16.29% db (14% wb) under an air mass flow rate of 0.1037 kg/s within 29.73 minutes and 22.95 minutes, with average temperatures and relative humidities of 80.3°C and 80.9°C and 12.28% and 8.14%, respectively. The average drying rate, specific energy consumption, and specific moisture extraction rate were 0.043 kg/minute and 0.050 kg/minute, 5.454 kWh/kg and 4.763 kWh/kg, and 0.204 kg/kWh and 0.241 kg/kWh for SA-FBDIBF and SAHP-FBDIBF, respectively. In SA-FBDIBF and SAHP-FBDIBF, the dryer thermal efficiencies were average values of 12.28% and 15.44%; in addition, the pickup efficiencies were 33.55% and 43.84% on average, whereas the average solar and biomass fractions were 10.9% and 10.6% and 36.6% and 30.4% for SA-FBDIBF and SAHP-FBDIBF, respectively. The drying of paddy occurred in the falling rate period. The experimental dimensionless moisture content data were fitted to three mathematical models. Page’s model was found best to describe the drying behaviour of paddy.

Design of Hybrid Drying- Dedusting Unit Processor for Rough Rice Processing

2008 ◽  
Vol 4 (6) ◽  
Author(s):  
Law Chung Lim ◽  
Wan Ramli Wan Daud
Keyword(s):  
Moisture Content ◽  
Fluidized Bed ◽  
Separation Efficiency ◽  
Cross Flow ◽  
Drying Kinetics ◽  
Rice Husks ◽  
Two Stage ◽  
Fluidized Bed Dryer ◽  
Rough Rice ◽  
Superficial Gas Velocity

Advanced drying technology enables drying of rough rice and dedusting of rice husks to be carried out simultaneously in the same unit processor. This paper reports the efficiency of dedusting of rice husks in a two-stage inclined cross flow fluidized bed dryer and the drying kinetics of rough rice in a batch fluidized bed dryer as well as the conceptual design of a hybrid drying – dedusting unit processor. Experimental works had been carried out using rough rice (a Group D particle according to Geldart classification of powders) in a 2.5 m height two-stage inclined fluidized bed column of cross sectional area of 0.61m x 0.15m and a 3 m high batch fluidized bed dryer. The objectives of the study was to investigate the separation efficiency of dedusting of rice husks in the two-stage cross flow fluidized bed dryer and to study the drying kinetics of rough rice drying in the batch fluidized bed dryer. The experimental results showed that the dedusting separation efficiency at low superficial gas velocity gave unsatisfactory separation of merely 40% of rice husks. At higher superficial gas velocity, separation efficiency of rice husks as high as 93% was achieved. In addition, higher distributor inclination angle gave slightly improved separation efficiency. The drying kinetics showed that the residence time that is required to reduce the moisture content of rough rice to 18% (intermediate storage moisture content for second stage drying) is 3 minutes whereas the residence time that is required to reduce the moisture content to 13% (desirable final moisture content) is approximately 10 minutes regardless of the effect of kernel cracking. It was also found that higher drying temperatures gave higher drying rate. A conceptual design has been developed based on the results obtained in the studies. In order to maximize the heat utilization and to carry out two processes viz. dedusting and drying in one unit processor, it is suggested that drying – dedusting can be carried out in a multistage mode where drying is taken place at each stage while dedusting is taking place at the upper stage. This concept can be applied to a packed bed or a fluidized bed unit processor.

scholarly journals Method of producing parboiled rice without steam by fluidized bed dryer

2020 ◽  
Vol 187 ◽  
pp. 01002
Author(s):  
Asadayuth Mitsiri ◽  
Somkiat Prachayawarakorn ◽  
Sakamon Devahastin ◽  
Wathanyoo Rordprapat ◽  
Somchart Soponronnarit
Keyword(s):  
Moisture Content ◽  
Fluidized Bed ◽  
Rice Yield ◽  
Experimental Result ◽  
Rice Starch ◽  
Parboiled Rice ◽  
Starch Gelatinization ◽  
Fluidized Bed Dryer ◽  
Head Rice ◽  
Head Rice Yield

A more simple methodology of producing parboiled rice is subject to be investigated in this work with proposed the method, the gelatinization of rice starch, commonly taking place at the steaming step in the traditional process, and drying are combined and replaced by a hot air fluidized bed dryer. A pilot-scale continuous fluidized bed, with a maximum capacity of 140-150 kg/h, has been designed, constructed and tested. Suphanburi 90 paddy variety with high amylose content was dipped into hot water at temperatures of 70, 80, 83°C for 4.0, 3.3, 3.2 h, respectively, to get the moisture content around 47-55% db and dried at 150-170°C using air speed of 3.5 m/s. The paddy bed depth within the dryer was 3 and 5 cm. In the dryer operation, the exhaust air was fully recycled and reheated again by 30 kW electrical heaters to the desired temperature. The experimental result has shown that parboiled rice with a different degree of starch gelatinization could be produced by this technique. The degree ranged between 80-100% as examined by differential scanning calorimeter. The exit moisture content was given in a range of 14-21% db, relying on the drying temperature and soaking time. The aforementioned exit moisture contents were not a detrimental effect on head rice yield although the tempering was not included. The head rice yield was given in the range of 59-66%, depending on the degree of starch gelatinization. The starch granules lost their original shape as revealed by scanning electron microscope.

scholarly journals Drying behavior, diffusion modeling of cuminum cyminum L. undergoing microwave-assisted fluidized bed drying

2018 ◽  
Author(s):  
Gholamreza Askari ◽  
Atefe Babaki ◽  
Zahra Emamdjomeh
Keyword(s):  
Fluidized Bed ◽  
Effective Diffusivity ◽  
Air Velocity ◽  
Cuminum Cyminum ◽  
Fluidized Bed Dryer ◽  
Microwave Assisted ◽  
Air Temperatures ◽  
Drying Behavior ◽  
Fluidized Bed Drying ◽  
Kinetics Of

In order to conserve cuminum cyminum L. during long storage periods, the drying kinetics of this seed undergoing microwave-assisted fluidized bed dryer at various microwave output power (300, 600 and 900w), air velocity (10, 15 and 20 m/s) and air temperatures (45, 55 and 65ᵒc) were studied. The main aim of this research is developing a mathematical model of mass transfer to investigate the microwave-assisted fluidized bed drying of cuminum cyminum L. seed. In this paper, we tried to discover a good model to evaluate moisture effective diffusivity (Deff). Keywords: cuminum cyminum L, microwave-assisted drying, mathematical modeling,

scholarly journals THE INFLUENCE OF STIRRER ON THE DRYING OF WHEAT PARTICLES IN A FLUIDIZED BED AT LOW AIR VELOCITY

2021 ◽  
Vol 21 (3) ◽  
pp. 170-182
Author(s):  
Russul A. Kadhim ◽  
Ekhlas M. Fayyadh ◽  
Sadeq H. Bakhy
Keyword(s):  
Moisture Content ◽  
Fluidized Bed ◽  
Air Velocity ◽  
Low Velocity ◽  
Drying Time ◽  
Fluidized Bed Dryer ◽  
Bed Height ◽  
Air Supply ◽  
Outside Diameter ◽  
Equilibrium Content

This study represents an attempt to reduce the drying time of wet grain wheat of the fluidized bed dryer (FBD), using straight blades, and debates the effect of stirrer on the whole drying time at different static bed heights. Experiments for FBD were conducted at the low velocity of air supply (1.45 cm/s) with moisture content for grain wheat 12% and ambient temperature of 37°C for each static bed height (9, 12, and 15 cm). FBD was made from a glass cylindrical column with inside diameter 4.6 cm, outside diameter (5.2 cm) and length (116 cm). The results showed an enhancement of (12- 20.5%) in the total drying time for bed height (9 and 15) cm, respectively. Also, increasing bed height from 9 cm to 15 cm possesses no influence on the equilibrium content of moisture in both techniques of drying either stirred fluidized bed or conventional fluidized bed.  

scholarly journals Simulation and Analysis of Plug Flow Fluidized Bed Dryer

2020 ◽  
Vol 9 (7) ◽  
pp. 805-811
Keyword(s):  
Mass Transfer ◽  
Moisture Content ◽  
Heat And Mass Transfer ◽  
Fluidized Bed ◽  
Plug Flow ◽  
Small Scale ◽  
Outlet Temperature ◽  
Drying Process ◽  
Fluidized Bed Dryer ◽  
Hot Air

Today many industries now use the dryer as a part of grain-drying process even during wet and dry seasons. This helps in reducing spoilage and wastage of paddy. Mostly the available industrial dryers are expensive to purchase and to maintain its smooth functioning. This study therefore is a step to design a simple Plug flow fluidized dryer that can lead to introduce small scale dryers to paddy process industry. The Plug flow fluidized bed dryers are designed and fabricated in this study consists of the drying chamber, hot air distributer plate, hot air inlet and exit system, paddy entry and exit system, fluidization chamber unit with temperature control unit and the centrifugal fan. The evaluation of dryer is based on drying time and reduction in moisture content and outlet temperature of paddy on quality parameters. Dryer dimensions are very important to analyze heat and mass transfer analysis of the Plug flow fluidized bed drying process of paddy grains. It was found d that heat and mass transfer properties of paddy grains in fluidized bed dryer was decreases as the time of drying passes and very rapid at the start of drying. The model present here predicts about dryer dimensions along safe zone of rough rice moisture content with other parameters. Simulation results show a good agreement between the simulation model and the existing simulation models

scholarly journals Paddy Drying in Batch Fluidized Bed and Scale-up Simulation in Continuous Operation Mode

2017 ◽  
Vol 2 (6) ◽  
pp. 430 ◽  
Author(s):  
Suherman Suherman ◽  
Mohammad Djaeni ◽  
Dyah Hesti Wardhani ◽  
Andri Cahyo Kumoro
Keyword(s):  
Moisture Content ◽  
Fluidized Bed ◽  
Air Temperature ◽  
Operation Mode ◽  
Scale Up ◽  
Drying Rate ◽  
Two Phase ◽  
Fluidized Bed Dryer ◽  
Fluid Bed ◽  
Experimental Works

The objective of this research is to develop the industrial-scale fluid bed dryer for paddy by scale-up of lab-scale experimental data. The developed dryer was conducted by simulation using a two phase model. Firstly, the experimental works by using lab-scale batch fluid bed dryer, was conducted to determine the drying curve of paddy (Xin 0.32 kg/kg dry base). In the experimental works,the inlet air temperature was varied (°C): 40; 50; 60. The drying rate curves as a function of moisture content showed only decreasing drying rate period. Then, a very good agreement between the measured and simualtion results of the profile of moisture content in solids was produced by simulator. Finally, asimulated continuous fluidized bed dryer for paddy with dimension 5 m of length and 1.5 of width was succesfully performed, in which the influence of mass solid flow rate 0.1; 0.2; 0.4 tons/h, height of bed 0.25; 0.50; 0.75 m, and air temperature 50; 70; 100 °C on drying process were studied. Keywords: Paddy; fluid bed dryer; batch, contonious;  modelling; simulation

Sign in / Sign up

Export Citation Format

Share Document