Graduation date: 1998

Experiments were conducted in a 0.91 m diameter half-cylindrical spouted bed/spout-fiuid bed column equipped with a 60° conical base and semi-circular inlet orifice diameters of 76 to 140 mm. Three particulate solid materials were studied: 3.25 mm polystyrene, 4.72 mm brown beans and 6.71 mm green peas. Beds with static depths of 0.55 to 2.60 m were contacted with air, both in the standard spouted bed and the spout-fluid bed mode. The dependent hydrodynamic parameters studied included minimum spouting velocity, maximum spoutable bed height, spout shape and diameter, fountain height, dead zone dimensions, overall bed pressure drop, fluid distribution in the annulus, longitudinal and radial pressure profiles in the annulus, and regime maps for the spout-fluid bed. Correlations for minimum spouting velocity developed on smaller vessels generally gave poor predictions for the large diameter vessel employed in this work and failed to predict the observed dependence of U[formula omitted]₈ on the static bed height. The empirical correlation due to McNab (1972) was found to predict the average spout diameter very well for standard spouted beds, while the correlation due to Hadzisdmajlovic et al. (1983) gave a reasonable prediction for spout-fluid beds. Substantial dead zone regions where particles were stagnant were observed in the lower portion of the vessel. The Littman et al. (1977) equation overestimated the maximum spoutable bed height, while the McNab and Bridgwater (1977) equation gave a value which appeared to be far too high. The observed fountains were extremely dilute, and their heights always exceeded the corresponding static bed heights for the conditions studied. The Epstein and Levine (1978) equation gave good estimates of overall bed pressure drop. The longitudinal fluid velocity in the annulus was well predicted by the modified Lefroy-Davidson (1969) equation due to Epstein et al. (1978) and was reasonably predicted by the Mamuro-Hattori (1968) model in the cylindrical portion. However, both equations gave poor predictions in the conical base portion. In the conical base section, the Rovero et al. (1983) equation predicted the correct trend, but consistently overestimated U[formula omitted] by a considerable margin. Both the Epstein and Levine (1978) equation and the Lefroy and Davidson (1969) equation were found to be in good agreement with the experimental longitudinal pressure profiles. The radial distribution of pressure in the annulus for any bed level was observed to be nearly constant when there was auxiliary flow. A computer model based on the Ergun equation gave useful qualitative predictions of the fluid flow distribution in the annulus. Four fairly distinct flow regimes were delineated in this work for cases where there were auxiliary air flow: (1) spouting-with-aeration; (2) spout-fluidization; (3) submerged jets, slugs and bubbles in fluidized bed, and (4) packed bed. The minimum total fluid flowrate for spouting-with-aeration always exceeded the minimum spouting flowrate, but was smaller than the minimum fluidization flowrate. The minimum total fluid flowrate for spout-fluidization was found to be equal to the minimum fluidization flowrate. / Applied Science, Faculty of / Chemical and Biological Engineering, Department of / Graduate

Many industrial processes require contact between particles and a fluid or spray in order to effect drying, coating or granulation. One device capable of contacting fluid and particles efficiently is a spouted bed in which a jet of fluid is injected into solid particles. This forms an open channel or spout and induces material circulation in a downward moving annulus. For the continuous throughput of solids, knowledge is required of the mixing and particle motions within the bed. When processing mixtures of particles differing in size or density, the components are often found to segregate into regions rich in larger or denser particles. In a spouted bed this tendency could affect the mixing of solids and residence times of different size fractions with which the process performance is associated. Distributions of particle residence times were measured using a novel magnetic method of tagging. A thin coat of soft iron powder was applied to form tracer particles, a technique having potential for the investigation of mixing in many industrial processes. In this study, perfect mixing was observed for mono-size particle feeds and perfect self-mixing of each component in binary-size feeds. Generally, although not universally, the smaller particles in a mixture passed through the bed more quickly than larger particles. As the bed depth and gas flow rate were increased independently, the difference between the mean res- idence times of the components became greater and was also shown to be dependent on the position of the solids outlet. The difference in residence times is attributed to segregation within the bed. Different residence times for each component will arise if the particles segregate in the spout, the fountain, the free surface, the annulus or as they are drawn off from the outlet. From the studies on a 150 mm diameter bed, the key processes occur on the free surface and in the neighbourhood of the outlet. In larger diameter beds, segregation on the free surface is predicted to be of prime importance, especially when economy dictates the operation of the bed at low gas flow rates. The particles would then be deposited on the free surface near the spout and the cascading of solids towards the perimeter would lead to segregation.

No description available.

Combustion of Minto coal, a sub-bituminous eastern coal which is highly agglomerating and has a high sulphur content, was carried out in a 0.15 m internal diameter half-column spout-fluid bed combustor in inert beds of sand, with limestone addition for sulphur capture. The average bed temperature ranged from 800 to 900°C, flue gas oxygen level was 2.5 to 11.0%, auxiliary to total air was 0 to 0.50, and Ca/S molar ratio was 2.5. High vale coal was employed in hydrodynamic runs. Aspects studied included combustion efficiency, sulphur capture efficiency, axial and radial temperature profiles, axial O₂ and CO₂ concentration profiles, axial SO₂ concentration profiles, minimum spouting velocity, spouting stability, and maximum spoutable bed height. The principal problem encountered with Minto coal in this equipment was agglomeration during the heat-up period. A spout-fluid bed has proved to be great favourable for handling agglomerating coal relative to the standard spouted bed. When limestone was used as bed material, less sintering was encountered. However, limestone could not stand up to spouting for prolonged periods because of excessive attrition. Combustion efficiencies were found to be higher than 80% in the temperature range of 800 to 900°C without solid fines recycle. An increase of temperature between 800°C and 840°C was beneficial for combustion efficiency, while a further increase up to 885°C did not seem to have a significant effect on combustion efficiency. Increase of auxiliary/total air ratio was favourable to combustion efficiency at elevated temperatures. Sulphur capture efficiency passed through a maximum with increasing temperature between 800°C and 900°C The maximum value was obtained at around 830°C. NOx emission increased linearly with increasing flue gas oxygen level. No abrupt temperature increase above the bed surface was observed in both spouted and spout-fluid beds investigated in the present study. Temperature may increase above the bed surface for low excess oxygen runs in view of the substantial amount of combustion found to occur in the freeboard. Temperatures were more uniform after the introduction of auxiliary air. Most oxygen was consumed below the bed surface. Axial profiles showed a significant SO₂ jump in the spout over the bed height. Combustion and sulphation could be considered to occur in two main stages: (1) Combustion of carbon, at the same time as most of the sulphur is released. (2) Sulphation of the sorbent. The Mathur and Gishler (1955) and Wu et al. (1987) equations gave poor agreement with the minimum spouting velocity, Ums, over the entire range of temperature. For large particles Ums tended to increase with increasing temperature, while for small particles it decreased with increasing temperature. Gas viscosity should be taken into consideration for predicting Ums. A considerably greater effect of auxiliary to total air ratio, q/Qt, on total minimum spouting velocity was found at elevated temperatures than at room temperature. At the maximum spoutable bed height, the value of Um/Umf was found to decrease with increasing temperature and to be smaller than unity at elevated temperatures. The McNab and Bridgwater (1977) expression correctly predicted the observed trends of Hm and worked reasonably well at high temperatures, although it was found to over-predict Hm at lower temperatures. Hm decreased with increasing temperature for all particle sizes, with a faster decrease for smaller particles. Fluidization in the annulus was never observed as the termination mechanism of spouting at high temperatures. / Applied Science, Faculty of / Chemical and Biological Engineering, Department of / Graduate

No description available.

Orientador: Sandra Cristina dos Santos Rocha / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-15T13:40:56Z (GMT). No. of bitstreams: 1 Rosa_GabrielaSilveirada_M.pdf: 1952306 bytes, checksum: 6e39c34ab96794dd18a4ddc2c6083579 (MD5) Previous issue date: 2010 / Resumo: A uréia é o fertilizante nitrogenado mais utilizado no Brasil, e seu uso tem aumentado nas últimas décadas. O recobrimento das partículas de uréia é realizado, principalmente, para que o nitrogênio tenha uma liberação lenta, aumentando assim seu tempo de disponibilidade para as plantas. O objetivo deste trabalho foi recobrir os grânulos de uréia com uma suspensão aquosa de natureza polimérica em leito de jorro, a fim de minimizar as perdas de nitrogênio (amônia) por volatilização. O desenvolvimento do trabalho consistiu em: caracterizar as partículas de uréia; formular e caracterizar a suspensão de recobrimento; estudar a fluidodinâmica da partícula no leito de jorro; desenvolver um planejamento experimental do tipo composto central rotacional para o recobrimento; e avaliar a liberação de nitrogênio por volatilização. As variáveis estudadas no planejamento foram: temperatura do ar de jorro (Tar), vazão da suspensão de recobrimento (Ws) e pressão do ar de atomização (Pat); e como respostas avaliou-se a eficiência do recobrimento e o crescimento da partícula. Os resultados para a eficiência do processo de recobrimento e crescimento da partícula ficaram na faixa de 44 a 74 % e 1,1 a 2,6 %, respectivamente. Após a realização do planejamento experimental, fazendo uso das condições otimizadas, determinou-se a cinética de crescimento da partícula, obtendo-se um coeficiente de crescimento linear de 1,13.10-3 min-1. Nestas mesmas condições realizou-se o recobrimento utilizando vinhaça, em substituição à água, na suspensão de recobrimento, resultando em valores de eficiência e crescimento similares aos obtidos com o uso da suspensão aquosa. As análises de volatilidade mostraram que o filme de recobrimento proporcionou diminuição das perdas por volatilização na faixa de 3 a 57 %, sendo estes resultados bastante satisfatórios. As análises obtidas por microscopia eletrônica de varredura demonstraram que o filme formado sobre as partículas recobriu toda superfície de forma uniforme e homogênea / Abstract: Urea is the most used nitrogen fertilizer in Brazil, and its use has been increasing in the last decades. The coating of urea particles is accomplished, mainly, to obtain slow liberation of the nitrogen content, increasing its availability for the plants. The aim of this work was to analyze the urea particles coating with an aqueous polymeric suspension in spouted bed, in order to minimize nitrogen (ammonia) losses by volatilization. The development of the work consisted in: physically characterizing the urea particles; formulating and characterizing the coating suspension; studying the fluid-dynamic of the particles in the spouted bed; developing a central composite rotatable design (CCRD) of experiments for the coating process; and evaluating the nitrogen release by volatilization. The effects of inlet air temperature, coating suspension flow rate and atomizing air pressure on the coating process efficiency and on particle growth were analyzed. The results showed efficiency and particle growth in the range of 44 to 74 % and 1.1 to 2.6 %, respectively. The urea growth kinetics during coating was determined for the optimal operating conditions and a linear growth coefficient of 1.13.10-3 min-1 was obtained. At these same optimal conditions, the coating was carried out using vinasse in the formulation of the suspension, in substitution to the water. Similar results for efficiency and particle growth were obtained compared to the ones using the aqueous suspension. The volatilization analyses showed that the polymer film coating provided a decrease of the nitrogen loss in the range of 3 to 57 %, being these results well satisfactory. The quality of the coated surface was analyzed by scanning electronic microscopy (SEM) and showed uniform and homogeneous distribution of coating layer / Mestrado / Engenharia de Processos / Mestre em Engenharia Química

Orientadores: Osvaldir Pereira Taranto, Virginia Aparecida Silva Moris / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-10T18:40:09Z (GMT). No. of bitstreams: 1 Lopes_NadiaElizaCorrea_M.pdf: 3103834 bytes, checksum: fb203b4d1396353b5e15847051d51028 (MD5) Previous issue date: 2007 / Resumo: O recobrimento de partículas em leito de jorro tem se mostrado bastante promissor, tendo em vista o seu potencial de aplicações em diversos produtos como comprimidos, cosméticos, sementes, fertilizantes. A maioria dos trabalhos reportados na literatura são baseados em observações visuais, em colunas construídas com material transparente, operados a pressão e temperatura ambiente. Porém, o reconhecimento visual dos regimes de escoamento não é possível em escala industrial ou com altas pressões. Logo, o objetivo desse trabalho foi identificar modificações ocorridas durante o processo de recobrimento de partículas em leito de jorro, pela comparação de observações visuais em conjunto com os espectros de potência obtidos a partir da aquisição de dados de queda de pressão em tempo real, utilizando a técnica FFT (Fast Fourier Transform). Para este estudo foram utilizadas partículas de diferentes formas, ABS e poliestireno, com diâmetro médio de 3,03 mm e 3,81 mm, respectivamente, e suspensão polimérica a base de Eudragitâ. O recobrimento foi realizado em um leito de jorro cone cilíndrico, confeccionado em acrílico com as seguintes dimensões: H = 70 cm, Dc = 14,3 cm, Di = 4 cm e ? = 60°, as condições operacionais foram pré-fixadas para cada partícula baseadas em ensaios preliminares. As flutuações da queda de pressão foram determinadas utilizando o software LabView 7.1, a uma taxa de amostragem de 400 Hz. Os resultados permitiram identificar durante o recobrimento a redução na taxa de circulação de partículas, zonas mortas e até ¿completo¿ colapso do leito, tanto por variações fluidodinâmicas visualmente observadas no leito, quanto por alteração espectral on line durante os experimentos de recobrimento. No futuro essa identificação pode ser útil como ferramenta no desenvolvimento de um sistema de controle ao processo de recobrimento / Abstract: The coating of particles in spouted has shown sufficiently promising, in view of its potential of applications in several products such as tablets, cosmetics, seeds, fertilizers. However, the works reported in literature had been predominantly based on visual observations, through columns constructed with transparent material, operated the pressure and ambient temperature. Furthermore, the visual recognition of flow regimes is not possible in industrial scale or with high pressures. Soon, the aim of this work was to identify modifications accured during the coating of particle in spouted bed, the comparison of the visual behavior with the power spectrum gotten from the acquisition of data of pressure drop in real time, using technique FFT (Fast Fourier Transform). For this study had been used particles of ABS and polystyrene, with average diameter of 3,03 mm and 3.81 mm, respectively, and aqueous polymeric suspension the base of Eudragitâ. The coating was carried through in a conical-cylindrical spouted bed, confectioned in acrylic with the following dimensions: H = 70 cm, Dc = 14,3 cm, Di = 4 cm and ? = 60°, the operational conditions had been fixed for each particle based in preliminary assays. The fluctuations of the drop pressure had been acquired using software LabView 7.1, to a rate of sampling of 400 Hz. The results had allowed to identify during the coating the reduction in the circulation rate of particle, zones deceased and until complete collapse of the spouted bed, as much for fluid-dynamics variations visually observed in the spouted bed, how much for spectral alteration during the coating experiments. In the future this identification can be useful development a control process tool / Mestrado / Engenharia de Processos / Mestre em Engenharia Química

Orientadores: Osvaldir Pereira Taranto, Flavio Vasconcelos da Silva / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-07T20:04:54Z (GMT). No. of bitstreams: 1 Pavanelli_PaulaEdilene_M.pdf: 1842381 bytes, checksum: ae8746d54834e8c938141f3e78903477 (MD5) Previous issue date: 2006 / Resumo: Este trabalho apresenta o controle e monitoramento em tempo real do regime de jorro estável através do método de identificação dos regimes de contato gás-sólido por medidas de pressão no leito de jorro. O trabalho foi realizado em duas etapas: 1) identificação em tempo real dos regimes fluidodinâmicos no processo em leito de jorro baseada na análise espectral das flutuações de queda de pressão do leito e 2) controle do processo em regime estável por malha PI. O sistema constitui-se de um leito construído em acrílico com dimensões de 0,70m de altura de coluna e 0,143m de diâmetro interno, operando com três diferentes partículas, esferas de vidro (dp = 2,59mm e Pp = 2,487 g/cm3), poliestireno (dp = 2,19mm e Pp = 1,196 g/cm3) e ABS (dp = 3,08mm e Pp = 1,029 g/cm3). Determinou-se a faixa da freqüência dominante 7,2-7,9 Hz, característico do regime de jorro estável, através do algoritmo da Transformada Rápida de Fourier (FFT) para cada partícula. Todas as medidas de pressão do leito durante o processo foram coletadas pelo sistema de aquisição através da placa PCI 6024E (National Instruments) utilizando o software LabView 7.1TM. Com o intuito de controlar o regime de jorro estável no processo em leito de jorro foram definidas como variáveis controlada e manipulada a freqüência dominante do espectro de potência (Hz) e o sinal de comando para o inversor de freqüência (V), respectivamente. A freqüência dominante foi determinada pela análise espectral das flutuações de queda de pressão no leito. O sinal de comando para inversor de freqüência atuava na variável de processo vazão de ar. Aplicaram-se perturbações degrau em malha aberta na variável manipulada para determinar os parâmetros do controlador e implementou-se a malha de controle no processo. Nos experimentos em malha fechada foram aplicadas perturbações na carga como adição de partículas e alteração na posição de abertura da válvula de ar de entrada no leito afim de testar o desempenho do controlador. Os resultados obtidos mostraram que o controlador PI manteve o sistema operando em regime estável mesmo quando aplicadas perturbações na carga, atingindo assim o objetivo do trabalho proposto / Abstract: This work describes the control and on line monitoring of the spouted bed steady regime using the gas-solid contact regimes identification method by pressure measurements. The work presents two main features: 1) the on line identification of fluid dynamic regimes in the spouted bed process based in the spectral analysis of the pressure fluctuations and 2) the process control using PI controllers. Experiments were performed in an acrylic cylindrical column 0.70m high and with 0.143m of internal diameter. The bed was made of three different particles: glass spheres (dp = 2.59mm and Pp = 2.4873 g/cm3), polystyrene (dp = 2.19mm and Pp = 1.1962 g/cm3) and ABS (dp = 3.08mm and p = 1.0286 g/cm3). The dominant frequency band was determined: 7.2-7.9 Hz for steady regime, through the algorithm of the Fast Fourier Transform (FFT), for each particle. All the measurements of pressure during the process were collected by a data acquisition system and using software LabView 7.0TM. The procedure to control the steady regime in the spouted bed process was: define the dominant frequency as the controlled variable and the signal of command for frequency inverter as the manipulated variable. The dominant frequency was determined by the spectral analysis of pressure fluctuations in the spouted bed. The command signal for frequency inverter affected the air flow variable. Step disturbances were applied in open loop in the manipulated variable to determine the parameters of the controller and control system was implemented in the process. Step disturbances like addition of particles in the spouted bed and change the position of opening of the air valve were applied in closed-loop to test the performance of the controller. The results show that PI controller was able to maintain the system operating in steady regime when disturbances were applied in the feed stream, which was the goal of this research / Mestrado / Engenharia de Processos / Mestre em Engenharia Química

Orientadores: Sandra Cristina dos Santos Rocha, Antonio Marsaioli Junior / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-13T10:14:46Z (GMT). No. of bitstreams: 1 Lescano_CesarAugustoAgurto_D.pdf: 2604640 bytes, checksum: f057c35fa84a33f1e932ab0c420a5210 (MD5) Previous issue date: 2009 / Resumo: O aproveitamento de resíduos industriais tem se tornado muito importante para evitar contaminação do meio e reaproveitar recursos até então considerados desperdícios ou perdas nas indústrias químicas e de alimentos. Na atualidade não se tem um valor aproximado da produção de leite de soja no mundo, mas sabe-se que grandes quantidades de resíduo são geradas pela produção do leite de soja, resíduo este que na literatura se denomina "Okara". Uma forma de aproveitar este resíduo é através de uma operação de secagem. A secagem é uma tecnologia amplamente utilizada pelas indústrias para manter a qualidade e prolongar a vida de prateleira dos produtos devido à diminuição das reações degradativas. Outro resultado da secagem é a diminuição do tamanho e peso do produto, facilitando assim seu transporte e armazenamento. No entanto, ainda hoje, apesar dos avanços tecnológicos nas indústrias químicas e de alimentos, persistem problemas quanto aos métodos específicos adequados para a secagem dos diferentes materiais biológicos, especialmente aqueles usados para alimentação humana. O resíduo de leite de soja é rico em proteínas, fibras e vitaminas, o que o torna de grande importância para diminuir o grande déficit de proteína que tem a população mundial, além de ser possível elaborar novos produtos utilizando o Okara seco como ingrediente e desta forma dar valor agregado aos novos produtos. O Okara apresenta-se como um material particulado muito úmido 80% (b.u.), e com alto teor de umidade superficial. A realização de uma operação mecânica de prensagem anterior à operação de secagem é necessária, para reduzir o teor de umidade até cerca de 60% (b.u.), otimizando dessa maneira a secagem, sem gastos não necessários de energia. O Okara é um material termo-sensível e, enquanto úmido, altamente deteriorável. Após o processo de prensagem, este material é particulado, altamente coesivo, de difícil escoamento, poroso e com alto teor de umidade interna (não podendo ser caracterizado como uma pasta). O objetivo desta pesquisa é estudar a secagem do resíduo do leite de soja, Okara, utilizando três tipos de secadores: secador de leito de jorro, secador de cilindro rotativo com aplicação de microondas e secador de forno de microondas. A secagem no leito de jorro foi realizada em batelada, enquanto, no secador de cilindro rotativo com aplicação de microondas, foi realizada em forma contínua. Foi necessária a utilização de material inerte nestes dois secadores: no secador de leito de jorro o inerte que apresentou melhor fluidodinâmica junto com o Okara úmido foi o polipropileno; diferente do secador rotativo, onde o inerte que apresentou melhor acompanhamento no transporte do Okara. dentro do cilindro foi o poliestireno. O processo de elaboração do Okara foi o mesmo para os dois equipamentos. As variáveis de processo analisadas no secador de leito de jorro foram: temperatura do ar de secagem, razão entre a vazão do ar e a vazão de jorro mínimo e tempo de trituração do material; no secador rotativo com aplicação de microondas as variáveis independentes analisadas foram: temperatura e vazão do ar de secagem e potência das microondas. Para os dois secadores foi elaborado um planejamento fatorial 2³, tendo como respostas avaliadas: teor de umidade para um determinado tempo de secagem e constantes do modelo de Page para a cinética de secagem (esta última apenas para o secador de leito de jorro). Foi ainda avaliado o desempenho operacional de ambos secadores, através da produtividade e eficiência térmica do processo. Foram também determinadas as propriedades físicas para o material antes e à saída nos secadores. O secador de forno de microondas foi utilizado para determinar as curvas de secagem, controlando-se as mesmas variáveis independentes analisadas no secador de cilindro rotativo. / Abstract: The use of industrial residues has become more and more important to avoid the environment contamination and to make use of resources considered wastes in the chemical and food industries. Actually, the approximated soy milk production in the world is unknown; however, it is known that large amounts of its residue, named "Okara", are generated by its production. Drying is an operation that could make this residue viable. The drying is a technology widely used by the industries to improve the quality and extend the shelf-life of the products due the decrease of the degraded reactions. Another result of a drying process is the decrease of the product's weigh and size, facilitating its transport and storage. However, until now, despite the technologic overhauls in the chemical and food industries, problems persist on defining the specific appropriate methods to dry different biological materials, mainly those used as human food. The soy milk residue is rich in proteins, fibers and vitamins, what makes it important in decreasing the enormous protein deficit of the world population, beyond the possibility of elaborating new products using Okara as ingredient, thus giving aggregate value to these new products. Okara is a very moist particulate material, 80% (b.u.), with high content of superficial moisture. A mechanic pressing operation before drying is indicated to decrease the Okara initial moisture content to around 60% (b.u.) and in this way optimize the drying process, without non-necessaries energy losses. The Okara is a thermo-sensible material and, while wet, highly deteriorative. After pressing, this material is particulate, highly cohesive, hard flowing, porous and with highly internal moist content (being not possible to be characterized as a paste). The objective of this research is the analysis of the soy milk residue drying using three types of dryers: conventional spouted bed dryer, rotary cylindrical dryer assisted by microwaves and microwave oven drier. The drying in the spouted bed was made in batch process while, in the rotary cylindrical dryer with application of microwaves it was conducted continuously. The use of inert material inside the dryer was necessary in both cases: in the spouted bed dryer, the inert that showed better fluid-dynamic with the Okara was the polypropylene, while in the rotary dryer the inert that showed better transport monitoring of Okara particles was the polystyrene. The same procedure was followed to prepare the Okara for both equipments. The variables analyzed in the spouted bed dryer were: drying air temperature, ratio between the air flow rate and minimum spout flow rate and time of material shredding; in the rotary cylindrical dryer assisted by microwaves, the independent variables were: drying air temperature and flow rate and microwave power. For both dryers, an experimental factorial design, 2³, was applied and the responses analyzed were: Okara moisture content for a fixed drying time and parameters of Page model for the drying kinetics (the last for the spouted bed dryer only). Operational performance was also determined for both dryers by productivity and process thermal efficiency. Physical properties were determined for Okara before drying and after the dryer exit. The microwave oven dryer was used to determine the drying kinetics, controlling the same variables as in the rotary cylindrical dryer. / Doutorado / Engenharia de Processos / Doutor em Engenharia Química