Thesis DESARROLLO DE PROGRAMA COMPUTACIONAL PARA EL DISEÑO Y DIAGNÓSTICO DE SISTEMAS DE TRANSPORTE NEUMÁTICO EN FASE DILUIDA
Date
2016
Authors
WEIPPERT MARTÍNEZ, VICENTE SAMUEL
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Abstract
El objetivo principal del presente trabajo es elaborar un programa con la capacidad de determinar la pérdida de presión y demás parámetros requeridos para diseñar un sistema de transporte neumático que opere en fase diluida. Debido a la complejidad de la elaboración de un modelo analítico para la interacción entre gas y sólidos es que el modelo propuesto se basa tanto en expresiones analíticas como en correlaciones empíricas.El modelo desarrollado obtiene de forma separada la caída de presión en la fase gaseosa y la fase sólida. Para la fase gaseosa se utiliza una modificación de la clásica ecuación de Darcy-Weisbach, incluyendo el efecto de la compresibilidad del aire. Por otra parte, la fase sólida depende de un factor “K”, el cual incorpora el efecto de múltiples variables en el comportamiento final del sistema. Para las curvas y codos, el modelo se basa en el estudio realizado por Schuchart, donde también la pérdida de carga se divide en fase gaseosa y fase sólida pero con otras relaciones de por medio, cobrando gran importancia el radio de curvatura del accesorio.La plataforma utilizada para operar el modelo es Microsoft Excel, con las funcionalidades que otorga el uso de Visual Basic for Applications (VBA), de manera de hacer lo más intuitivo y automatizado cada procedimiento requerido para obtener los resultados numéricos.Para verificar el funcionamiento del programa, se contrastó con valores obtenidos de literatura y ensayos de laboratorio propios, con el fin de verificar y ajustar algunas constantes y parámetros.Finalmente, el modelo es válido, funciona de forma correcta, es capaz de estimar la caída de presión y el diagrama de estado de un sistema de transporte neumático en fase diluida, obteniendo errores menores al 15% en la gran mayoría de los casos, y es una opción para diseñar o diagnosticar sistemas reales.
The main objective of the current work is to develop a software that has the capability to determinate the pressure drop and other relevant parameters for the design and diagnose of a dilute-phase pneumatic conveying system of bulk solids. Due the complexity in the development of an analytical model for the interaction between gas and solids, the proposed model in the current work is based both on analytical expressions and empirical correlations.The developed model obtains separately the pressure drop in the gas phase and solid phase. For the gas phase, a modification of the classic Darcy-Weisbach equation is used, including the air compressibility effect. Otherwise, the solid phase depends on a “K” factor, which incorporates the effect of multiple variables in the final system behavior. For bends and elbows, the model is based on Schuchart research, in which the pressure drop is also divided in gas and solid phase, but in a different way, important being the radius of curvature of bends and elbows.Microsoft excel is the platform selected to operate the model, using the functionalities that provide Visual Basic for Applications (VBA), in order to make more intuitive and automatized each required procedure to obtain the numeric results.To test the performance of the program, a comparison with values obtained from literature and experimental results was done to verify and adjust some constants and parameters.Finally, the model is valid and works fine to estimate the pressure drop and the state diagram of a dilute-phase pneumatic conveying system, obtaining percentage errors less than 15% in most cases, and is an option to design or diagnose real systems.
The main objective of the current work is to develop a software that has the capability to determinate the pressure drop and other relevant parameters for the design and diagnose of a dilute-phase pneumatic conveying system of bulk solids. Due the complexity in the development of an analytical model for the interaction between gas and solids, the proposed model in the current work is based both on analytical expressions and empirical correlations.The developed model obtains separately the pressure drop in the gas phase and solid phase. For the gas phase, a modification of the classic Darcy-Weisbach equation is used, including the air compressibility effect. Otherwise, the solid phase depends on a “K” factor, which incorporates the effect of multiple variables in the final system behavior. For bends and elbows, the model is based on Schuchart research, in which the pressure drop is also divided in gas and solid phase, but in a different way, important being the radius of curvature of bends and elbows.Microsoft excel is the platform selected to operate the model, using the functionalities that provide Visual Basic for Applications (VBA), in order to make more intuitive and automatized each required procedure to obtain the numeric results.To test the performance of the program, a comparison with values obtained from literature and experimental results was done to verify and adjust some constants and parameters.Finally, the model is valid and works fine to estimate the pressure drop and the state diagram of a dilute-phase pneumatic conveying system, obtaining percentage errors less than 15% in most cases, and is an option to design or diagnose real systems.
Description
Catalogado desde la version PDF de la tesis.
Keywords
FASE DILUIDA , PROGRAMA COMPUTACIONAL , TRANSPORTE NEUMATICO