Secado Research Papers - Academia.edu (original) (raw)

En el presente trabajo se realizó la deshidratación del tomate, que es un fruto con un
contenido de agua aproximado al 94%. Se utilizó un secado de bandejas para alimentos
en condiciones constantes de temperatura (a 68ºC), y rebanadas de tomate con área
aproximada de 22.06 cm2 por cara. A tales rebanadas se les determinó el contenido de
humedad en diferentes tiempos así como el material completamente seco que poseen.
Utilizando los datos obtenidos y una serie de cálculos se pudo determinar la velocidad
de secado del tomate, y las curvas de secado obtenidas se analizaron en los periodos
antecrítico y poscrítico, para su posterior comparación.

- by Regino Sanchez Uriarte
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- Secado, Operaciones Unitarias, Secado de alimentos

Operación unitaria de Secado

- by Edgar Verastegui
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- Secado, Operaciones Unitarias

En el presente trabajo se estudiaron dos técnicas de colado utilizando una pasta arcillosa comercial usada para la elaboración de productos de cerámica blanca tipo loza en el municipio antioqueño del Carmen de Viboral. Los dos tipos de conformación en verde comparados fueron el colado tradicional o al aire y el colado asistido por microondas. Además de la conformación en verde, también se compararon dos métodos de secado, el convencional y el secado con microondas. Para dicho estudio se utilizó una barbotina con un 60% de contenido de sólidos y un 40% de agua destilada con base en la masa total. El dispersante utilizado fue silicato de sodio y la cantidad óptima que se obtuvo, gracias al estudio reológico, fue de 0,15% con base en la masa de sólidos. Los moldes de escayola se fabricaron con una relación en masa de 1:1. Para determinar las diferencias entre los métodos de conformación en verde y los métodos de secado se midió la velocidad de formación de pared, la velocidad de secado, se hicieron curvas de Bigot, índice de sensibilidad al secado y perfiles de humedad de las probetas y finalmente éstas se sometieron a pruebas de flexión, densidad y porosidad. Las pruebas realizadas mostraron que las piezas cerámicas coladas con MW se obtienen en un menor tiempo que con la técnica tradicional y el secado con esta misma técnica disminuye los tiempos de permanencia de las piezas en el secadero. Lo anterior conduce a una mayor productividad, menor consumo energético y una reducción de gases contaminantes de la atmosfera sin detrimento de las propiedades físicas y mecánicas de las piezas.

- by Francisco Javier Ramírez-Gil
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- Secado, Cerámica Tradicional, Colado

apuntes de la clase de masa 3
Humidificación y Secado

- by Alexis Cruz Zabalegui
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- Ingenieria Quimica, Química, Humidity, Secado
- by David M
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- Mass Transfer, Leaching, Filtration, Crystallization
- by Cecilia Grunauer
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- Lima, Secado, Pectin, Limon Sutil
- by Lalo Herrera
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- Secado, Equipo
- by Bryan Maldonado
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- Microstructure, Modeling, Drying, Suspensions

The present communication resumes the contents of an investigation project sponsored by the BASQUE COUNTRY UNIVERSITY. The object of the work consists in obtaining the properties of moist air in a wide range of industrial utilization including applications such as driers and transport by fans. The purpose was to find out the approximate grade mentioned by Hyland & Wexler/3/ authors of recognized prestige in this area. The thermodynamic and psychrometric properties of moist air selected cover amply the requirements for industrial application now and the ones expected in the near future. The selected range covers the pressures and temperatures in the use of transport of air by fans and useful atmospheric data in mines and places up to 5000 m height with pressures between 0,54 and 1,35 bar and temperatures between-50 and 350°C with intervals of 1°C to boiling temperature and 5°C from then upwards. The details are shown on tables with three entries. First entry shown below with full details referring to pressure, altitude, and unit systems. Second entry can be the temperature of dry bulb and third the relative humidity with intervals of 5% (or humidity ratio with intervals of 25 g/kg dry air). This original way to show data of moist air is very practical and will probably be used by other authors in the future. The heading of the table presents the used letter symbols and nomenclature in accordance with the one used by ASHRAE/2/. When the relative humidity has no sense, the humidity ratio is taken as entrance parameter within a range from 0 to 500 g/kg dry air, selected in accordance with the industrial experience of the authors considered as most appropriate.

- by J. Javier Doria
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- Refrigeration Air Conditioning, Drying, Secado, Aire Acondicionado

The aim of this study was to model the drying kinetics of microwave and fluidised bed of parchment coffee beans (Coffea arabica L.) using a semi-theoretical approach. A completely randomized design with six treatments: three with microwave drying (MD) and the rest with microwave fluidised bed drying (MFBD) was carried out. The drying curves were established until reaching a final moisture content between 10 and 12 % w.b. Results indicated that the drying time decreased as the microwave power level increased. When MFBD was used, drying times increased approximately 4-fold compared to MD treatments. The values of effective diffusivity for coffee beans treated with MD and MFBD ranged from 0.913 to1.72×10-9 m 2 .s-1 and from 0.23 to 0.42×10-9 m 2 .s-1 , respectively. Although all the models presented high goodness of fit, the two-term model presented the highest R 2 (>0.98) and lowest RMSE (0.0128-0.0285).

- by Revista Ingenierías Universidad de Medellín
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- Coffee, Microwave, Modeling, Drying

Effect of drying conditions upon dehydration kinetic of mulberry (Morus alba). The objective of this work was to determine the dehydration kinetics of mulberry under different conditions of temperature, speed and ai r humidity, between June and December 2006 in Costa Ri ca. White mulberry leaves (Morus alba) with an age of 75 days were used as substrate for the drying process. The drying kinetics was investigated in a electric convective dryer with a single tray (diameter of 0.22 m) loaded with 122 ±1 g of mulberry leaves per batch, maintaining the process until a humidity content of 5 % was reached. Three drying ai r temperatures (60 °C, 75 °C and 90 °C), two fixed airflow rates (1 m/s and 2.5 m/s) and two ai r humidity contents (12 g/kg dry ai r and 45 g/kg dry air) were evaluated for a total of 12 treatments. The drying data were fitted to the Newton mathematical model. Graphics for drying velocity vs. time and vs. humidity were also obtained. The drying kinetics was in good agreement with a typical Newton model showing high correlation coefficients. There was a significant effect (p<0.05) of temperature, velocity and humidity of air upon drying, where temperature was the most influential of them all, followed by velocity and finally by air humidity. Increasing any of these parameters implied a reduction of the drying time. The effect of temperature on drying was most pronounced at a air speed of 1 m/s

- by Alejandro Chacón-Villalobos
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- Kinetics, Drying Behavior of Food Materials, Processing, Drying