scholarly journals Effect of Biodegradable Binder Properties and Operating Conditions on Growth of Urea Particles in a Fluidized Bed Granulator

Materials ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2320 ◽  
Author(s):  
Ehsan Zhalehrajabi ◽  
Kok Keong Lau ◽  
Ku Zilati Ku Shaari ◽  
Seyed Mojib Zahraee ◽  
Seyed Hadi Seyedin ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Air Temperature ◽  
Scale Up ◽  
Cost Effective ◽  
Stokes Number ◽  
Operating Conditions ◽  
Air Velocity ◽  
Air Inlet ◽  
Lower Temperature ◽  
Penetration Time

Granulation is an important step during the production of urea granules. Most of the commercial binders used for granulation are toxic and non-biodegradable. In this study, a fully biodegradable and cost-effective starch-based binder is used for urea granulation in a fluidized bed granulator. The effect of binder properties such as viscosity, surface tension, contact angle, penetration time, and liquid bridge bonding force on granulation performance is studied. In addition, the effect of fluidized bed process parameters such as fluidizing air inlet velocity, air temperature, weight of primary urea particles, binder spray rate, and binder concentration is also evaluated using response surface methodology. Based on the results, binder with higher concentration demonstrates higher viscosity and higher penetration time that potentially enhance the granulation performance. The viscous Stokes number for binder with higher concentration is lower than critical Stokes number that increases coalescence rate. Higher viscosity and lower restitution coefficient of urea particles result in elastic losses and subsequent successful coalescence. Statistical analysis indicate that air velocity, air temperature, and weight of primary urea particles have major effects on granulation performance. Higher air velocity increases probability of collision, whereby lower temperature prevents binder to be dried up prior to collision. Findings of this study can be useful for process scale-up and industrial application.

scholarly journals Thermal Performance of Tropical Atrium

2013 ◽  
Vol 12 (1) ◽  
pp. 34-40 ◽  
Author(s):  
Mohammad Baharvand ◽  
Mohd Hamdan Bin Ahmad ◽  
Tabassom Safikhan ◽  
Sayyed Mohammad Mahdi Mirmomtaz
Keyword(s):  
Energy Demand ◽  
Building Energy ◽  
Air Velocity ◽  
Humid Climate ◽  
Air Inlet ◽  
Architectural Feature ◽  
Common Problems ◽  
Hot And Humid Climate ◽  
Lower Temperature ◽  
Tropical Climates

Abstract Atrium is a popular architectural feature utilized widely by building designers and owners to bring various benefits such as adequate daylight, circulation spaces and surfaces for landscape applications. But atrium problems in tropical climates such as excessive daylight, glare and high temperature, which lead to increase building energy demand, have been reported. To avoid and reduce these unpleasant features, a side-lit atrium has been suggested. Although researchers proposed side-lit atrium to prevent common problems of atria, the lack of precedent research on this issue compels these authors to study atrium performance in hot and humid climate. So the research aims to examine two different atrium roof form types in terms of temperature and ventilation impacts in hot and humid climate of Malaysia using DesignBuilder as a simulation program. The results indicate lower temperature of side-lit model with better airflow pattern in comparison with top-lit model while the top-lit model provides higher air velocity at the air inlet and outlet.

Treatment of Slaughterhouse Wastewater Using Fluidized Bed Biofilm Reactors

1987 ◽  
Vol 19 (1-2) ◽  
pp. 1-10 ◽  
Author(s):  
Chun T. Li ◽  
Wen K. Shieh ◽  
Chun S. Wu ◽  
Ju S. Huang
Keyword(s):  
Fluidized Bed ◽  
Cost Effective ◽  
Maximum Amount ◽  
Biofilm Reactor ◽  
Operating Conditions ◽  
High Concentration ◽  
Slaughterhouse Wastewater ◽  
Chemical Coagulation ◽  
Biofilm Reactors ◽  
Cost Effective Alternative

The oxygenic fluidized bed biofilm reactor(FBBR) was evaluated in a laboratory investigation for treatment of pig slaughtering wastewater (slaughterhouse wastewater). Because the slaughterhouse wastewater contains a high concentration of grease, chemical coagulation/flocculation was adopted as the pretreatment step prior to FBBR treatment. The performance of the FBBR was evaluated at BOD loadings of between 8.5 to 98.5 kg/m3-day, hydraulic retention times of between 8.8 to 30.8 minutes, recirculation ratios of between 1 to 6, and feed BOD concentrations of between 305 to 602 mg/L. Under these operating conditions, removal efficiencies of BOD, grease, and NH3-N were in the range of 71 to 94%, 29 to 84%, and 20 to 73%, respectively. Both BOD and grease of the slaughterhouse wastewater used could be lowered to 40 and 10 mg/L, respectively, at a BOD loading of 20 kg/m3-day in order to meet effluent requirements to be enforced in Taiwan in 1990. Because the maximum amount of oxygen that could be dissolved in the oxygenation device used in this investigation was 40 mg/L, the FBBR would become anaerobic when the BOD loading applied exceeded 50 kg/m3-day. Relatively constant biomass holdups (10,000 mg TVS/L) could be maintained in FBBRs over the BOD loadings applied via the practice of regular biofilm separation and biomass wasting. The combined chemical coagulation/flocculation-FBBR process provides a feasible and cost-effective alternative for treatment of slaughterhouse wastewater.

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

scholarly journals Optimisation of Tray Drier Microalgae Dewatering Techniques Using Response Surface Methodology

Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2327 ◽  
Author(s):  
Ruth Anyanwu ◽  
Cristina Rodriguez ◽  
Andy Durrant ◽  
Abdul Olabi
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Air Temperature ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Slight Effect ◽  
Air Velocity ◽  
Independent Variables ◽  
Air Supply ◽  
Central Composite

The feasibility of the application of a tray drier in dewatering microalgae was investigated. Response surface methodology (RSM) based on Central Composite Design (CCD) was used to evaluate and optimise the effect of air temperature and air velocity as independent variables on the dewatering efficiency as a response function. The significance of independent variables and their interactions was tested by means of analysis of variance (ANOVA) with a 95% confidence level. Results indicate that the air supply temperature was the main parameter affecting dewatering efficiency, while air velocity had a slight effect on the process. The optimum operating conditions to achieve maximum dewatering were determined: air velocities and temperatures ranged between 4 to 10 m/s and 40 to 56 °C respectively. An optimised dewatering efficiency of 92.83% was achieved at air an velocity of 4 m/s and air temperature of 48 °C. Energy used per 1 kg of dry algae was 0.34 kWh.

scholarly journals An Experimental Study of the Drying Mechanism of Olive Cake

2007 ◽  
Vol 25 (4) ◽  
pp. 261-271
Author(s):  
Huseyin Gunerhan
Keyword(s):  
Experimental Study ◽  
Developing Countries ◽  
Fluidized Bed ◽  
Air Temperature ◽  
Low Cost ◽  
Air Velocity ◽  
Olive Cake ◽  
Renewable Source ◽  
Suitable Material ◽  
Fluidized Bed Dryer

In this study, an investigation on olive cake as on alternative fuel and effect of drying air temperature and drying air velocity is conducted. In many developing countries olive cake is considered as a biomass and can be used in very large amounts at very low cost. The effect of drying air temperature and air velocity at constant humidity conditions was studied. A process for drying of olive cake in a fluidized bed dryer is proposed. Results of these experiments of the olive cake indicated that olive cake has an excellent potential to be a renewable source of energy and suitable material for these types of dryers.

Optimization of Pistachio Nut Drying in a Fluidized Bed Dryer with Microwave Pretreatment Applying Response Surface Methodology

2017 ◽  
Vol 12 (3) ◽  
Author(s):  
Reza Amiri Chayjan ◽  
Mohammad Kaveh ◽  
Nesa Dibagar ◽  
Moein Zarrin Nejad
Keyword(s):  
Response Surface Methodology ◽  
Energy Consumption ◽  
Fluidized Bed ◽  
Air Temperature ◽  
Specific Energy ◽  
Color Change ◽  
Specific Energy Consumption ◽  
Air Velocity ◽  
Fluidized Bed Dryer ◽  
Total Color Change

Abstract Thin-layer drying kinetics of pistachio nuts were examined experimentally as a function of drying conditions in a fluidized bed dryer with microwave pretreatment. Four drying specifications of diffusivity, shrinkage, specific energy consumption and total color change were calculated and the effects of parameters were studied. Numerous experimentations were conducted at three levels of air temperature (40, 55, 70 °C), air velocity (1.2, 2.93, 4.01 m/s), and microwave power (270, 450, 630 W). The variation ranges of diffusivity, shrinkage, energy consumption and color change were recorded from 5.01×10–10 to 5.07×10–9 m2/s, from 26.95 % to 13.13 %, from 1.04 to 9.23 kWh and from 10.44 to 17.17, respectively. According to response surface methodology, optimum condition of drying process occurred at microwave power of 630, air temperature of 70 ˚C, and air velocity of 1.2 m/s. In this optimum point, the values of diffusivity, shrinkage, specific energy consumption and total color change were 4.865×10–9, 14.22 %, 2.164 kWh and 12.312, respectively.

scholarly journals Agglomeration process in the fluidized bed, the effecting parameters and some applications

2018 ◽  
Vol 13 (3-4) ◽  
pp. 159-163
Author(s):  
Hira Yuksel ◽  
Nur Dirim
Keyword(s):  
Heat Transfer ◽  
Fluidized Bed ◽  
Air Temperature ◽  
Mechanical Resistance ◽  
High Porosity ◽  
Air Velocity ◽  
Mixing Rate ◽  
Agglomeration Process ◽  
Mass And Heat Transfer ◽  
Bed Agglomeration

The agglomeration process has been commonly used to improve the functional properties of powder products to form larger agglomerates. Agglomeration provides a granular structure to powders, reduce the dusting and improving their characteristics, such as storage stability, wettability, dispersibility, and solubility. This process can be performed by different methods, one of which is fluidized bed agglomeration widely used in food processing since the agglomerates produced by this technique have high porosity, low density, and good mechanical resistance. At the same time, this process is influenced by many factors; e.g., inlet air temperature, air velocity, mixing rate, and properties of the binder agents. Inlet air temperature affects the mass and heat transfer; air velocity prevents caking and accelerates mass and heat transfer; mixing rate allows mixing the binder agent uniformly over the particles; and the properties of the binder agent, such as concentration and viscosity have an impact on the properties of the final product. These four factors should be well known and controlled so that the agglomerates produced have the desired properties. Furthermore, the use of fluidized bed agglomeration results in products that can be used in widespread areas and in high quantities, and this method also creates the opportunity to utilize excess foods not consumed.

scholarly journals Spatial and Temporal Distribution of Temperature, Relative Humidity and Air Velocity in a Parallel Milking Parlour During Summer Period

2015 ◽  
Vol 15 (2) ◽  
pp. 517-526 ◽  
Author(s):  
Piotr Herbut ◽  
Sabina Angrecka ◽  
Grzegorz Nawalany ◽  
Krzysztof Adamczyk
Keyword(s):  
Relative Humidity ◽  
Air Temperature ◽  
Ventilation System ◽  
Temporal Distribution ◽  
Operating Conditions ◽  
Air Velocity ◽  
Summer Period ◽  
Air Movement ◽  
Air Stream ◽  
Relative Air Humidity

Abstract The research aimed at determining the most significant parameters affecting the microclimate of milking parlours, such as temperature, relative humidity and air movement in a parallel milking parlour in real operating conditions. The research was conducted in the summer period, when the risk of heat stress in cattle is higher. To check welfare of cows during milking, days with air temperature >25°C and days with temperature equal or lower than 25°C were analysed. Observation and analysis were performed for air flow in milking parlour, range of supplied air stream and how air movement affects cattle. It was observed that the irregular distribution of air movement led to the development of diverse air velocity in different zones of the milking parlour (0.2-9.0 m∙s-1). As a consequence, the conditions inside the barn were not homogenous for all the cattle. A significant effect of the cows and external air temperature (which depends indirectly on orientation of the milking parlour relative to cardinal directions) on temperature increase (approx 6°C) was concluded, with relative air humidity at the level of 85-90%, during the milking, which led to systematic decrease of microclimatic comfort for cattle. Based on the conducted research, it was concluded that the design of ventilation systems in parallel milking parlours should be preceded by increased research not only on ventilation system efficiency but also on the distribution of flow ventilated air.

Computational and Experimental Investigation of Emissions in a Highly Humidified Premixed Flame

2003 ◽  
Author(s):  
Fredrik Hermann ◽  
Jens Klingmann ◽  
Rolf Gabrielsson
Keyword(s):  
Air Temperature ◽  
Combustion Efficiency ◽  
Reaction Scheme ◽  
Operating Conditions ◽  
Aerodynamic Load ◽  
Inlet Temperature ◽  
Atmospheric Conditions ◽  
Air Inlet ◽  
Stirred Reactor ◽  
Maximum Humidity

Emission formation and flame stability were investigated, both experimentally and computationally, for premixed combustion with varying amounts of water vapor in the mixture. Emission measurements were made in a gas turbine combustor at atmospheric conditions, using Danish Natural Gas (NG) as fuel. The emissions were mapped as a function of humidity, inlet air temperature, equivalence ratio and aerodynamic load. Operating conditions were chosen to match what can be expected from e.g. an EvGT cycle for power generation. The inlet air temperature was slightly lower than the inlet temperatures that would be found in a recuperated cycle. The degree of humidity was varied from 0w% to 33w% of the airflow in the experiment, while the air inlet temperature was varied from 500K to 800K. Computations were made using a single Perfectly Stirred Reactor (PSR) model and a reaction scheme with 821 reactions and 69 species. It was found that the NOx emissions were strongly reduced by the addition of water. Most of this decrease vanishes in practical combustion since richer combustion is required to keep CO emissions (combustion efficiency) at a tolerable level. The maximum humidity was found to be dependent on inlet air temperature and aerodynamic load. In this experiment, the maximum humidity achieved was 33%.

scholarly journals Drying of oil palm frond particles in a fluidized bed dryer with inert medium

2013 ◽  
Vol 19 (4) ◽  
pp. 593-603 ◽  
Author(s):  
May Yun ◽  
Ifa Puspasari ◽  
Masrinda Tasirin ◽  
Meor Talib ◽  
Wan Daud ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Air Temperature ◽  
Oil Palm ◽  
Mass Ratio ◽  
Air Velocity ◽  
Drying Time ◽  
New Model ◽  
Fluidized Bed Dryer ◽  
Oil Palm Frond ◽  
Palm Frond

Drying characteristic of oil palm frond fibres was investigated in a fluidized bed dryer with the presence of inert particles. Sand was used as inert material. Effects of air temperature (60, 70 and 80?C), air velocity (0.79 and 0.85 m/s) and mass ratio of fibres to sand (1:0, 1:1 and 1:2) on the drying curves were investigated. The results showed that the shortest drying time was obtained with the highest air temperature, air velocity and fibres to sand mass ratio. The experimental drying data were fitted to nine existing drying models namely Lewis, Page, Modified Page, Henderson and Pabis, Logarithmic, Two-term, Two-term exponential and Wang and Singh models and a proposed new model. The goodness-of-fit was determined based on the values of r2, c2 and RMSE. The results showed that the best quality of the fit was obtained using the proposed model. The new model was also validated for the superheated steam drying of oil palm empty fruit bunch from other work.

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