Novel method to meassure fine particle circulation rates in draft tube conical spouted beds

The spouted bed regime is an alternative contact method to fixed and fluidized beds. The ratio between the inlet diameter and particle diameter limits the scaling-up of spouted beds (the inlet diameter should be smaller than 20-30 times the particle diameter). The insertion of a draft tube is the way of overcoming this limitation. Particle cycle time is defined as the time the particle takes to travel from the top of the annulus downwards and back again to its starting point. Since the proportion of time spent by a particle in the spout is insignificant compared with that spent in the annulus, particle cycle times can be deduced from solid flow patterns in the annulus (1). Knowledge of particle cycle time is very useful to ascertain the bases of the spouted bed technique. Furthermore, information on this parameter and particle trajectories is essential for spouted bed applications, given that the average cycle time regulates energy and mass transfer, and influences chemical reactions (2). The most used technique to measure the solid cycle times is particle tracking, but monitoring of fine particles requires very sofisticated techniques, whose reliability is open to debate. Accordingly, the main aim of this work is to setup a device and develop a methodology for measuring the circulation rate of fine particles in conical spouted beds. The device is a sector located on the upper surface of the annulus, which collects the particles raining down in the fountain. Based on the information gathered, the factors of major influence on the solid circulation rate are determined and their effect is quantified. The material used for operation is building sand of0.6 mmparticle diameter, but glass beads (coarse particles) of4 mmdiameter have also been used so as to verify the methodology proposed by comparing the results with those obtained by monitoring a marked (painted) particle. REFERENCES 1. N. Epstein, J.R. Grace. Eds. Cambridge University Press: New York, 2011. 2. J. Makibar, A.R. Fernandez-Akarregi, I. Alava, F. Cueva, G. Lopez and M. Olazar. Investigations on heat transfer and hydrodinamics under pirolisis conditions of a pilot-plant draft tube conical spouted bed reactor. Chem. Eng. Process., 50: 790-798, 2011

Dotrina, erretorika eta erudizioa Mogelen erlijio liburuetan

Kristau dotrinaren irakaspena 1. Juan Antonio Mogel, Markinako apaizak (1745-1804), anaia-aita-aitonak mediku zituenak, bere burua arimen medikutzat zeukan ; arimazaintza eta arimak salbatzea, bere egitekotzat. Horretarako liburu onak idaztea zela onena uste zuen. Hain zuzen, haren idazlan gehienak kristauaren eginbideei buruzkoak dira. Horien artean mamitsu, mardul eta azalpenean oparoenak aipatuko ditugu lehenik ; bizi zela, ondokoak argitara zituen : 1801 : Confesio ta Comunioco Sacramentu..

Paper Art. Fibras papeleras en la Creación Artística. Producción y Edición

Nivel educativo: Grado. Duración (en horas): De 21 a 30 horasEn esta asignatura los estudiantes trabajan las posibilidades creativas y conceptuales que ofrece el papel como soporte y objeto, en su estructura y funciones. Articulando desarrollos y proyectos de intervención con fibras papeleras, en sistemas de impresión o estampación, y desde el contexto de la ilustración, el dibujo o el grabado. Mediante la elaboración de distintos soportes o matrices adecuados al proyecto gráfico, se desarrollan las posibilidades de la materia papel como medio configurador del dibujo, imagen u objeto, y su posterior producción y edición. La asignatura se enmarca en el Grado de Creación y Diseño (Minor de Ilustración), optativa de 4º, en el primer cuatrimestre del curso. Y la ejecución del proyecto se realiza entre las semanas 9 y 14 del cuatrimestre de las quince que conforman la misma. La realización del proyecto con la metodología ABP supone un 40% de la asignatura

Adéma-Zaldubiren hitzaldi, artikulu eta kantu zenbait

1. Gratien Adéma Zalduby apezak  (1828-1907) bere poesiagatik irabazi ditu euskal literaturan duen tokia eta euskaldunen ezagutza. Baina hitz laxozko idazle ere izan zen. Liburuska batzuk, laburrak nahiz luzexagoak argitara zituen : bi, Lurdeko Ama Birjinaren agertze eta mirakuiluak kontatzen dituztenak, beilariendako kantika eta otoitzekin osatuak (Baiona, 1875 eta 1877). Daranatzen arabera (RIEV 2, 1908 :122-123) erreboteko jokoaz eta Aldudez liburuska bana ere argitara zituen, bai eta Les ..

STUDY OF THE MINIMUM SPOUTING VELOCITY IN A DRAFT TUBE CONICAL SPOUTED BED

A study has been carried out on the hydrodynamics of conical spouted beds with a non-porous draft-tube. A hydrodynamic correlation has been proposed for calculating the minimum spouting velocity as a function of dimensionless moduli that take into account geometric factors, particle characteristics and operating conditions. A statistical analysis of the data obtained following a design of experiments shows that the inlet diameter, particle diameter and the height of the entrainment zone are the parameter of greater influence on the minimum spouting velocity

Ezkontide alarguna eta bizirik dirauen izatezko bikotearen babesa Euskal Zuzenbide Zibilearen naitaezko oinordetzan

[ES] El objetivo principal de este trabajo, en la Ley 5/2015, de 25 de junio, de Derecho Civil Vasco (LDCV), es analizar la protección en la sucesión forzosa del cónyuge viudo o pareja de hecho superviviente. De hecho, además de establecer por primera vez una regulación única y unitaria del Derecho civil vasco en toda la Comunidad Autónoma del País Vasco, a través de esta ley se han reformado diversos aspectos para mejorar la situación del cónyuge viudo o la pareja de hecho superviviente. En otras palabras, lo que se pretende abordar en esta investigación sería analizar si la nueva ley vasca responde a las necesidades sociales actuales, analizando si las protecciones sucesorias obligatorias son adecuadas a la situación actual del cónyuge viudo o pareja de hecho superviviente.[EU] Lan honen helburu nagusia, Euskal Zuzenbide zibilari buruzko ekainaren 25eko 5/2015 Legean (EZZL), ezkontide alargunak edo bizirik dirauen izatezko bikotekideak derrigorrezko oinordetzan jasotzen duen babesa aztertzea da. Izan ere, Euskal Autonomia Erkidego (EAE) osoan lehen aldiz euskal Zuzenbide zibil araudi bakar eta bateratua ezartzeaz gain, alargun zein bizirik dirauen izatezko bikotekidearen egoera hobetze aldera hainbat alderdi erreformatu dira lege honen bitartez. Beste hitz batzuetan, ikerketa honetan landu nahi dena euskal lege berriak gaur egungo beharrizan sozialei erantzuten dien aztertzea litzateke, derrigorrezko oinordetza babesak gaur egungo ezkontide alargun edo bizirik dirauen izatezko bikotekidearen egoerari begira egokiak ote diren aztertuz.[EN] The main purpose of this work is to examine the protection that the surviving spouse or civil partner receives in forced share succession under Law 5/2015 of 25 June on Basque Civil Law (LDCV). In fact, in addition to establishing, for the first time throughout the Autonomous Community of the Basque Country (CAPV), a single and unitary regulation of Basque civil law, a number of aspects have been amended in order to improve the situation of the surviving spouse and civil partner. In other words, what is intended to be dealt with in this study would be to examine whether the new Basque law responds to the current social needs by examining whether the protection of forced succession is appropriate to the current situation of the surviving spouse and civil partner

Amodioaren martirra (1900-1901), foiletoinobela ezezaguna

In this article we present an old Basque newspaper serial. This serial was unknown to this day, despite having been published in 1900-1901, and it constitutes the only such work in Basque. We focus on four aspects of this newspaper serial about an eternal triangle that mixes history and fiction: the author and the original novel, its translation and its publication as a serial, the most important features of the genre and the novel itself, and its value and inadequacies as a piece of translated work. As a result, we know now that the serial Amodioaren martirra ('The Martyr of Love') is an adaptation of a novel by Ernest Daudet, characterized by its monarchism and its counterrevolutionary ideology, and that the author tried to adapt the language typical of that genre to the Basque language

Correlation of the Minimum Spouting Velocity for the Design of Open-Sided Draft Tube Conical Spouted Beds for the Treatment of Fine Materials

The hydrodynamics of conical spouted beds provided with open-sided draft tubes have been studied for the treatment of fine particles. A correlation has been proposed for the calculation of the minimum spouting velocity as a function of dimensionless moduli that take into account the geometric factors of the contactor and the draft tube, particle characteristics and operating conditions

A neural-based modelling approach to estimate residence time and solids flow rate in a conical spouted bed with and without draft tubes

Spouted beds are an alternative contact method to the fixed and fluidized beds especially for handling coarse particles. Since its discovery in 1954 by Gishler and Mathur during grain drying in a fluidized bed, spouted beds have been widely studied and applied in different industrial processes, such as, particle coating, catalytic reactors, pyrolysis and drying of solids, pastes and suspensions. One of the main advantages of spouted beds over fluidized beds is its high degree of mixing between gas and solids within the bed due to a cyclical and uniform movement of particles, leading to high heat and mass transfer rates and also a homogeneous final product. Despite its advantages, the conventional configuration of the spouted bed still has some limitations; such as a high pressure drop for stable spouting, the existence of a maximum height for a stable spout with the corresponding scaling-up limitations and the highly dependable gas flow rates on stable spouting. In order to minimize these operational limitations, several spouted bed configurations have been proposed, the main ones being the spouted bed with a draft tube, the two-dimensional spouted bed and the spouted bed with supplementary aeration, among others. Solids residence time and flow rates are key parameters in the modeling, optimization and control of any process. Although predictions of solids residence time and flow rate are important issues that reflect the accuracy of the whole process simulation, difficulties arise in the use of either purely mechanistic or empirical approaches. In developing a reasonable theoretically based model, the only task is to estimate the values of the coefficients in the model, but, taking into account all relevant phenomena involved this model can prove to be impractical. Additionally, the seemingly overwhelming choice of structural options for empirical models may considerably hinder the modeling step. Artificial neural networks may be an effective alternative in that they can represent highly nonlinear processes, with flexibility and robustness against input noise and once they have been developed and their coefficients determined, they can provide a rapid response for a new input [1]. This neural network based model (MatLab® R2013a, Mathworks) uses the particle diameter dp, bed density ρb, cone angle γ, inlet diameter D0 and draft tubes characteristics as inputs whilst the maximum, mean and minimum residence times along with the solid flow rates are predicted with reasonable agreement with the experimental data, as shown in Figure 1 Please click Additional Files below to see the full abstract