The drying of sewage sludge by immersion frying

The objective of this work was to dry sewage sludge using a fry-drying process. The frying experiments were carried out in commercial fryers modified by adding thermocouples to the setup. During frying, typical drying curves were obtained and it was verified that, in relation to the parameters: oil temperature, oil type and shape of the sample, the shape factor the most effect on the drying rate, at least within the range chosen for the variables studied. Oil uptake and calorific value were also analyzed. The calorific value of the samples increased with frying time, reaching values around 24MJ/kg after 600s of frying (comparable to biocombustibles such as wood and sugarcane bagasse). The process of immersion frying showed great potential for drying materials, especially sewage sludge, obtaining a product with a high energy content, thereby increasing its value as a combustible.22227127

Drying of a Porous Material in a Pulsed Fluid Bed Dryer: The Influences of Temperature, Frequency of Pulsation, and Air Flow Rate

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)In this work, a four-section pulsed fluid bed apparatus with a 0.18m2 cross-section area was used to investigate the influence of pulsed-fluidization variables on the drying process of molecular sieves, a test material that was chosen because it presents an initial constant drying rate period. A two-level factorial design was developed to evaluate the influences of the inlet gas temperature40 and 70Cthe frequency of pulsation250 and 900rpmand the air flow rate500 and 600 m3(STP)/hon the drying rate. In addition, a comparison was made between the drying rates achieved with conventional and pulsed fluidization. Results showed that all the investigated variables affect the drying rate. Moreover, drying rates with conventional fluidization are considerably higher, which shows that one must expect a lower drying rate when pulsation is used in a drying process controlled by the external evaporation. Concerning fluid dynamics, this work also analyzed the influence of the frequency of pulsation on the pressure drop across the bed. The higher the frequency, the higher the pressure drop. That result can be explained by the reduction of channeling.272212219Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)School of Chemical Engineering of the University of Campinas - UNICAMPMaua Institute of Technology (IMT)OXITENOFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

The effect of initial size on the germination of pelleted broccoli seeds

An experimental study of broccoli (Brassica oleraceae, var Italica) seed pelleting was conducted in a 143 mm diameter conventional spouted bed granulator. The influence of initial seed size and seed condition (naked and pelleted seed) on germination is discussed. The experiments followed a mixed design of two and three factors, and the results were analyzed using response surface methodology. The pelleting process was carried out with broccoli seeds sorted by size using sieves with openings of 2.00, 1.68 and 1.48 mm. The naked and pelleted seeds for each size class were evaluated considering the germination capacity. The results did not show significant differences in germination capacity between pelleted and non-pelleted seeds for seeds of the same size class. Naked and pelleted seeds with initial sizes larger than 1.68 mm were the most representative and displayed the highest physiological quality.4851677168

Scale-up and spouting of two-dimensional beds

The objective of this paper is to present an analysis on the scale-up procedure of two-dimensional spouted beds. The, task was carried out with three different beds measuring 0.15, 0.30 and 0.80 in width; The conditions of scale-up were studied through geometrical similitude analysis. Some parameters of scale were adimensionalised, tested and validated in order to propose relationships capable of predicting values,of dependent properties. Those relationships should be followed in a prototype of an equipment of industrial scale. The-study permitted the development of correlations to predict values of maximum pressure drop, minimum spout velocity and maximum height of spouting.81226426

Drying of beans in a pulsed fluid bed dryer: Drying kinetics, fluid-dynamic study and comparisons with conventional fluidization

Fresh carioca beans (Phaseolus vulgaris) were submitted to convective drying in a pulsed fluidized bed (PFB) dryer. A full factorial design was developed in order to analyze the effects of the following process variables on the kinetic parameters of the Page's equation: inlet air temperature, airflow rate and frequency of pulsation. The only significant variable was the inlet temperature of air. At 60 degrees C, drying was also performed under conventional fluidization. No difference was observed between the drying curves under pulsed and conventional fluidization: therefore, due to the lower pumping requirement, energy savings can be achieved with the pulsed fluidization technique without affecting the production yield. Complementary fluid-dynamic evaluation showed that the maximum pressure drop is approximately the same in both regimes. However, under pulsed fluidization that maximum value is affected by the initial bed height and slightly by the frequency of pulsation. (c) 2006 Elsevier Ltd. All rights reserved.80124925

The Gaussian spectral pressure distribution applied to a fluidized bed

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The present work applies the methodology proposed by Parise er al. [M.R. Parise, O.P. Taranto, P.R.G. Kurka, L.B. Benetti, detection of the minimum gas velocity region using Gaussian spectral pressure distribution in a gas-solid fluidized bed, Powder Technol. 182 (2008) 453-458], as an alternative to the spectral analysis of pressure fluctuation measurements to find the region where the minimum velocity gas takes place in a gas-solid fluidized bed, that is, the zone where the bed is tending to defluidization. The technique is applied to analyze the effect of fixed bed height and particle density in defluidization conditions for particles of microcrystalline Cellulose and sand. Tests are carried out for three fixed bed heights (0.15, 0.20 and 0.25 m) and two particle densities (980 and 2650 kg/m(3)). Experiments show that the best conditions for identifying the defluidization zone are obtained with lower bed aspect ratios (H/D) and lower particle density. The results indicate the high potential of the proposed method for industrial applications, especially for on-line control of gas-solid fluidized bed processes where the defluidization phenomenon needs to be detected and avoided, (C) 2008 Elsevier B.V. All rights reserved.481120125Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Enteric coating process of diclofenac sodium pellets in a fluid bed coater with a wurster insert: Influence of process variables on coating performance and release profile

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)The objective of this work was to study the coating process of diclofenac sodium pellets, with the commercial aqueous coating suspension for enteric release - Acryl-Eze (R) MP, in a fluid bed coater with a Wurster insert. Coating experiments were performed following a 2(2) factorial design to determine the influence of process variables on coating performance, measured by the two response variables: efficiency (eta(%)) and agglomeration index (m(agg%)). Both response variables were found to be affected by inlet temperature and suspension flow rate with a 95% confidence level. This work also studied the release of diclofenac sodium coated and uncoated pellets in HCl 0.1 N and pH 6.8 phosphate buffer media. Results showed that the release of diclofenac sodium during the buffer stage was affected by the prior exposure to the HCl 0.1 N medium and a polymer weight gain above 9.7% (2.7 mg/cm(2)), was needed to modify the release in such a way that it remained below 10% for the first 120 min in HCl 0.1 N and above 75% in pH 6.8 for the next 45 min. Neither the drug content nor the release profiles were significantly affected by storage at 40 degrees C and 75% relative humidity. (C) 2012 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.243659666Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

IDENTIFICATION OF DEFLUIDIZATION REGION IN A GAS-SOLID FLUIDIZED BED USING A METHOD BASED ON PRESSURE FLUCTUATION MEASUREMENTS

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Industrial applications that involve fluidized bed operations must prevent the undesirable phenomenon of partial or complete bed defluidization. Defluidization can be avoided by increasing the gas velocity and/or, in some cases, changing the solid feed conditions in the system, provided that the changes in the hydrodynamics of the flow are detected early enough. The use of a technique that can perform an early detection of the defluidization condition in industrial applications is important, in order to avoid the loss of efficiency or even an undesirable shutting down of the process. The objective of this work is to show the application of a method for early detection of the condition where the bed is tending to the defluidization, in a gas-solid fluidized bed flow. The method is based on pressure fluctuation measurements. Experimental tests are carried out using two solid particles: microcrystalline cellulose and sand. Results show that the proposed method is efficient in detecting the fluidization condition in a conventional bubbling bed regime. The potential of application of the technique is also shown for the control of the defluidization phenomenon in industry.263537543Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Identification of defluidization in fluidized bed coating using the Gaussian spectral pressure distribution

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The partial or complete bed defluidization is an undesired phenomenon in industrial application involving fluidized bed operations. In the process of particle coating, the defluidization can be prevented by increasing the gas velocity and/or decreasing the coating suspension flow rate, if the changes in the hydrodynamics of the fluidization are early detected. For industrial applications, the use of a technique that can quickly identify the defluidization region is very important, avoiding loss of efficiency or even the necessity of shutting down the process. The purpose of the present work is to identify the defluidization region in a fluidized bed coating process using the Gaussian mean frequency, which is an alternative methodology based on pressure fluctuation analysis. Experiments were carried out in a Plexiglas column with a 0.143 m in inner diameter and 0.71 m in height, at a temperature of 70 degrees C. Microcrystalline cellulose (MCC) of 325 pm in diameter and an apparent density of 980 kg/m(3) was used as fluidizing particles, which was coated by a suspension based on Eudragit (R). All raw data sets of pressure in the plenum were collected at a sampling rate of 400 Hz, considering 2048 data points. LabView (R) 7.1 software was used for all data acquisition and signal processing. The results showed that the defluidization region can be clearly identified using the methodology employed. It also could have a high potential in industrial applications, especially for on-line control in order to avoid the defluidization region and consequently the efficiency loss of a coating process. (c) 2010 Elsevier B.V. All rights reserved.20641671SI149153Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq