Proposal for improving of paddy rice drying process in dryers inclined pools: Propuesta de mejoramiento del proceso de secado de arroz paddy en secaderos tipo albercas inclinadas

The operation of inclined type dryers for paddy rice is studied to improve their operation and efficiency, considering the variables of drying time, humidity distribution in the rice layer after drying and air velocities within the plenum. Simulating the distribution and velocities of the air flow before crossing the rice layer, the outlet ducts to the plenum are relocated and dampers are placed to distribute the flow evenly. On the other hand, it is proposed to replace the flat-type mesh with a zigzag-type mesh.  To verify the proposed modifications, a scale model was built to determine the humidity and drying time variation inside the rice layer, obtaining more uniform moisture percentages within the rice layer and a decrease in drying time.  Se estudia el funcionamiento de los secaderos tipo inclinado para arroz paddy, con el fin de mejorar su operación y eficiencia, considerando las variables de tiempo de secado, distribución de la humedad en la capa de arroz después del secado y velocidades del aire dentro del plenum. Simulando la distribución y velocidades del flujo de aire antes de cruzar la capa de arroz se reubican los conductos de salida al plenum y se colocan dampers que distribuyan uniformemente el flujo. Por otro lado, se propone la sustitución de la malla tipo plana por una malla tipo zigzag.  Para verificar las modificaciones propuestas se construyó un modelo a escala para medir la variación del tiempo de secado y la humedad dentro de la capa de arroz paddy, obteniendo porcentajes de humedad más uniformes dentro de la capa de arroz y disminución del tiempo de secado

Proposal for improving of paddy rice drying process in dryers inclined pools: Propuesta de mejoramiento del proceso de secado de arroz paddy en secaderos tipo albercas inclinadas

The operation of inclined type dryers for paddy rice is studied to improve their operation and efficiency, considering the variables of drying time, humidity distribution in the rice layer after drying and air velocities within the plenum. Simulating the distribution and velocities of the air flow before crossing the rice layer, the outlet ducts to the plenum are relocated and dampers are placed to distribute the flow evenly. On the other hand, it is proposed to replace the flat-type mesh with a zigzag-type mesh.  To verify the proposed modifications, a scale model was built to determine the humidity and drying time variation inside the rice layer, obtaining more uniform moisture percentages within the rice layer and a decrease in drying time.  Se estudia el funcionamiento de los secaderos tipo inclinado para arroz paddy, con el fin de mejorar su operación y eficiencia, considerando las variables de tiempo de secado, distribución de la humedad en la capa de arroz después del secado y velocidades del aire dentro del plenum. Simulando la distribución y velocidades del flujo de aire antes de cruzar la capa de arroz se reubican los conductos de salida al plenum y se colocan dampers que distribuyan uniformemente el flujo. Por otro lado, se propone la sustitución de la malla tipo plana por una malla tipo zigzag.  Para verificar las modificaciones propuestas se construyó un modelo a escala para medir la variación del tiempo de secado y la humedad dentro de la capa de arroz paddy, obteniendo porcentajes de humedad más uniformes dentro de la capa de arroz y disminución del tiempo de secado

Estudio de alternativas para la recuperacion de aguas residuales en el proceso de obtención de aceite de palma en la planta de beneficio de guaicaramo s.a. meta

En la planta de Guaicaramo, para el proceso de obtención del aceite de palma, las calderas producen la mayor demanda de agua utilizada en el proceso, aproximadamente 96000 m3 por año, este vapor al ser utilizado en este proceso genera condensados, que al reutilizarlos disminuiría la demanda de agua proveniente de pozos profundos  y  del río, por  lo que este estudio   plantea el   diseño de un   sistema de recuperación de los   condensados   que cumplan según parámetros determinados por la ABMA   (American Boiler   Manufacture Asociation)   para nuevamente alimentar a la caldera. También se analizaron los efluentes finales del sistema de tratamiento (EFST)   de diferentes partes del proceso que llegan a una piscina de lodos para su recuperación, para estas se propuso un diseño experimental utilizando materias primas de residuo de la empresa (cuescos de palma, fibra y tusa) y un solo tratamiento tradicional (Filtración o floculación o sedimentación) y mezclas con agua para buscar su posterior utilizacióncomo agua de alimentación de calderas.Palabras Clave: Diseño experimental; eficiencia de calderas; recuperación de aguas residuales; recuperación de condensados

Modelo matemático de la transferencia de calor en el hogar de una caldera pirotubular

The main pipe of a boiler called home, serves to harness the energy released from the fuel to evaporate water effects. excess air to observe changes in the amount of heat transfer is varied. To study the ESS software is used.El tubo principal de una caldera denominado hogar, cumple la función de aprovechar la energía liberada por el combustible para efectos de evaporar el agua. Se varía el exceso de aire para observar los cambios en la cantidad de transferencia de calor. Para el estudio se utiliza el software EES.

The Changing Landscape for Stroke\ua0Prevention in AF: Findings From the GLORIA-AF Registry Phase 2

Background GLORIA-AF (Global Registry on Long-Term Oral Antithrombotic Treatment in Patients with Atrial Fibrillation) is a prospective, global registry program describing antithrombotic treatment patterns in patients with newly diagnosed nonvalvular atrial fibrillation at risk of stroke. Phase 2 began when dabigatran, the first non\u2013vitamin K antagonist oral anticoagulant (NOAC), became available. Objectives This study sought to describe phase 2 baseline data and compare these with the pre-NOAC era collected during phase 1. Methods During phase 2, 15,641 consenting patients were enrolled (November 2011 to December 2014); 15,092 were eligible. This pre-specified cross-sectional analysis describes eligible patients\u2019 baseline characteristics. Atrial fibrillation disease characteristics, medical outcomes, and concomitant diseases and medications were collected. Data were analyzed using descriptive statistics. Results Of the total patients, 45.5% were female; median age was 71 (interquartile range: 64, 78) years. Patients were from Europe (47.1%), North America (22.5%), Asia (20.3%), Latin America (6.0%), and the Middle East/Africa (4.0%). Most had high stroke risk (CHA2DS2-VASc [Congestive heart failure, Hypertension, Age  6575 years, Diabetes mellitus, previous Stroke, Vascular disease, Age 65 to 74 years, Sex category] score  652; 86.1%); 13.9% had moderate risk (CHA2DS2-VASc = 1). Overall, 79.9% received oral anticoagulants, of whom 47.6% received NOAC and 32.3% vitamin K antagonists (VKA); 12.1% received antiplatelet agents; 7.8% received no antithrombotic treatment. For comparison, the proportion of phase 1 patients (of N = 1,063 all eligible) prescribed VKA was 32.8%, acetylsalicylic acid 41.7%, and no therapy 20.2%. In Europe in phase 2, treatment with NOAC was more common than VKA (52.3% and 37.8%, respectively); 6.0% of patients received antiplatelet treatment; and 3.8% received no antithrombotic treatment. In North America, 52.1%, 26.2%, and 14.0% of patients received NOAC, VKA, and antiplatelet drugs, respectively; 7.5% received no antithrombotic treatment. NOAC use was less common in Asia (27.7%), where 27.5% of patients received VKA, 25.0% antiplatelet drugs, and 19.8% no antithrombotic treatment. Conclusions The baseline data from GLORIA-AF phase 2 demonstrate that in newly diagnosed nonvalvular atrial fibrillation patients, NOAC have been highly adopted into practice, becoming more frequently prescribed than VKA in Europe and North America. Worldwide, however, a large proportion of patients remain undertreated, particularly in Asia and North America. (Global Registry on Long-Term Oral Antithrombotic Treatment in Patients With Atrial Fibrillation [GLORIA-AF]; NCT01468701

Study of different turbulence models to obtain the curves characteristics of a naca profile 2415 through the three-dimensional simulation of fluid flows

Se realizó un análisis computacional, mediante la técnica del CFD, del perfil NACA 2415, con los modelos de turbulencia Realizable K-ε y el modelo de turbulencia K-ω SST para obtener sus curvas aerodinámicas. El software utilizado fue el ANSYS FLUENT V14. La simulación se realizó con mallas no estructuradas y bidimensionales, en un dominio computacional cuyas dimensiones corresponden al túnel de viento AF6109 de la Universidad Nacional Experimental del Táchira, Venezuela. Las curvas aerodinámicas se realizaron para diferentes ángulos de ataque, los cuales consistieron en 0°, 4°, 8°, 12° y 16° respectivamente. Las condiciones de borde usadas están basadas en el túnel de viento AF6109. La simulación computacional se validó con las curvas aerodinámicas obtenidas mediante el diseño experimental realizado en el túnel de viento. Se concluye que el modelo de turbulencia K-ω SST predice mejor los gradientes adversos de presión.A computational analysis was performed, using the CFD technique, of the NACA 2415 profile, with the K-ε Realizable turbulence models and the K-ω SST turbulence model to obtain its aerodynamic curves. The software used was the ANSYS FLUENT V14. The simulation was performed with unstructured and two-dimensional meshes, in a computational domain whose dimensions correspond to the AF6109 wind tunnel of the National Experimental University ofTáchira, Venezuela. The aerodynamic curves were made for different angles of attack, which consisted of 0°, 4°, 8°, 12°and 16°respectively. The edge conditions used are based on the AF6109 wind tunnel. The computational simulation was validated with theaerodynamic curves obtained by the experimental design carried out in the wind tunnel. It is concluded that the turbulence model K-ω SST better predicts the adverse pressure gradients

Determination of connective heat transfer coefficients in an intermittent kiln

The determination of heat transfer coefficients are parameters of great importance when evaluating thermal losses in a system. Therefore, the present work reports the convective heat transfer coefficients in different positions of a rectangular kiln for the production of artisanal ceramic materials, located in Ocaña, Norte de Santander, Colombia, from which the heat losses present in the were determined. As a result, a virtual instrument was designed for temperature acquisition, using a data acquisition card, as well as a chassis and thermocouples generating a temperature report and their respective temperature profiles. The determination of heat transfer coefficients are parameters of great importance when evaluating thermal losses in a system. The energy supplied by the fuel is 51.21 kJ and the energy loss in the walls and floor of the brick kiln is 17.67 kJ, which represents 34.51% of the energy supplied. The thermal gradient in the kiln is not homogeneous, affecting the quality of the products. This will be avoided by building the walls with refractory materials

Proposal for improving of paddy rice drying process in dryers inclined pools

The operation of inclined type dryers for paddy rice is studied to improve their operation and efficiency, considering the variables of drying time, humidity distribution in the rice layer after drying and air velocities within the plenum. Simulating the distribution and velocities of the air flow before crossing the rice layer, the outlet ducts to the plenum are relocated and dampers are placed to distribute the flow evenly. On the other hand, it is proposed to replace the flat-type mesh with a zigzag-type mesh. To verify the proposed modifications, a scale model was built to determine the humidity and drying time variation inside the rice layer, obtaining more uniform moisture percentages within the rice layer and a decrease in drying time.Se estudia el funcionamiento de los secaderos tipo inclinado para arroz paddy, con el fin de mejorar su operación y eficiencia, considerando las variables de tiempo de secado, distribución de la humedad en la capa de arroz después del secado y velocidades del aire dentro del plenum. Simulando la distribución y velocidades del flujo de aire antes de cruzar la capa de arroz se reubican los conductos de salida al plenum y se colocan dampers que distribuyan uniformemente el flujo. Por otro lado, se propone la sustitución de la malla tipo plana por una malla tipo zigzag. Para verificar las modificaciones propuestas se construyó un modelo a escala para medir la variación del tiempo de secado y la humedad dentro de la capa de arroz paddy, obteniendo porcentajes de humedad más uniformes dentro de la capa de arroz y disminución del tiempo de secado