Engineering Commons^™

Development Of A Cold Model Fuild Coker Pilot Plant, Jessica A. Godin

Electronic Thesis and Dissertation Repository

Fluid Coking^TM is an upgrading process used to produce higher-value products from heavy hydrocarbons through thermal cracking. A Hot Pilot Plant is being designed for potential use to optimize commercial Fluid Cokers.

A Cold Model Fluid Coker was operated in this thesis to identify design limitations restricting operation at the required conditions. Design changes were implemented, and their impact on the system fluid dynamics were characterized. Successful operation of at required conditions was demonstrated.

Pressure measurements provided rapid feedback on potential issues. Models for bed expansion and entrainment flux were developed, which can be used to extrapolate to the …

Water Based Soil Fluidization Using A Soft Eversion Robot, James E. Hand

Doctoral Dissertations and Master's Theses

Soft robotics, a form of robotics that incorporates nonrigid components, continues to grow in scope, system design, and application. A recent addition to this field is the Vine Robot platform, a bio-inspired robot designed by Stanford University in 2017. Its method of movement, known as eversion, closely resembles the way that a vine grows along a tree, giving it its name. The focus of this research was to take its proven abilities of underwater vine-like movement and soil fluidization, a process where granular materials are converted from a solid-like state to a fluid-like state, to create an underwater eversion robot …

Cluster Acceleration And Stabilization In Downflow Catalytic Reactors: Experimental And Cpfd Simulation Studies, Cesar Alejandro Medina Pedraza

Electronic Thesis and Dissertation Repository

Particle cluster dynamics in downflow reactors are of great importance for the implementation of large scale, environmentally friendly catalytic processes. Studies should address particle cluster velocities, solids holdups, and individual cluster sizes to establish reliable models for the unit scale up.

In this PhD dissertation, the individual characteristics of particle clusters, such as cluster size, velocity, and particle volume fraction, were measured in the feeding, intermediate, and fully developed flow sections of a cold-flow model unit using CREC-GS-Optiprobes. The downer unit employed in this research had a 0.051 m ID and a 2 m high acrylic column. The feeding section …

A Laboratory Study On Fluidization Of Subgrade Under Cyclic Train Loading, Buddhima Indraratna, Mandeep Singh, Thanh Trung Nguyen, Serge Leroueil, Aruni Lakmali Abeywickrama Bamunusing Kankanamge, Richard B. Kelly, Tim Neville

Faculty of Engineering and Information Sciences - Papers: Part B

A long term issue that has hampered the efficient operation of heavy haul tracks is the migration of fluidized fines from the shallow soft subgrade to the overlying ballast, i.e., mud pumping. This paper presents a series of undrained cyclic triaxial tests, where realistic cyclic loading conditions were simulated at low confining pressure that is typical of shallow subgrade beneath a ballast track. Subgrade soil specimens with a low plasticity index collected from a field site with recent history of mud pumping were tested at frequencies from 1.0 to 5.0 Hz and a cyclic stress ratio (CSR) from 0.1 to …

The Energy Efficiency Of Separation Mixture "Solid-Solid" Method, Alisher Shonazarovich Abdullaev, Aziza Urazalievna Abdurahimova, Sadogat Shonazarovna Abdullaeva, Khabibulla Sagdullaevich Nurmukhamedov

Chemical Technology, Control and Management

Characteristics of using a fluidized bed in a hydro classifier for the separation of the mixture “pulp - peel” are shown. The study results of separation degree of the pulp R from the skin in three-phase fluidization as a function of the Reynolds number Re with the ratio of the gas and liquid phases G:L = 0.15:1 and G: W = 0.25:1 are presented. Research has found that with equivalent diameter of the skin of root and tuber crops de = 2-8 mm, with of gas and liquid phases G:L = 0.15: 1, and also with live cross-section of the …

Fluidized Bed Classroom Demonstration Unit, Theresa Chapa

Williams Honors College, Honors Research Projects

Fluid and Thermal Operations is a 4th year chemical engineering course at the University of Akron designed to introduce undergraduate students to the engineering and mathematical concepts behind the operation of a fluidized bed. The purpose of this honors project is to design and manufacture an inexpensive and portable unit that can be used in the classroom to visually demonstrate three functions of a fluidized bed to students. The fluidized bed is manufactured from items that can be purchased from a department or hardware store, is capable of being transported by a single person to and from a classroom and …

Conceptual Design Of A Pilot-Scale Pressurized Coal-Feed System, Taylor L. Schroedter

Theses and Dissertations

This thesis discusses the results and insights gained from developing a CFD model of a pilot-scale pressurized dry coal-feed system using the Barracuda CFD software and modeling various design concepts and operating conditions. The feed system was required to transport approximately 0.00378 kg/s (30 lb/hr) of pulverized coal from a vertical hopper to a 2.07 MPa (20.4 atm or 300 psi) reactor with a CO2-to-coal mass flow ratio of 1-2. Two feed system concepts were developed and tested for coal mass flow, CO2-to-coal mass ratio, steadiness, and uniformity. Piping system components also were evaluated for pressure drop and coal roping.With …

Development Of A Two-Fluid Drag Law For Clustered Particles Using Direct Numerical Simulation And Validation Through Experiments, Ahmadreza Abbasi Baharanchi

FIU Electronic Theses and Dissertations

This dissertation focused on development and utilization of numerical and experimental approaches to improve the CFD modeling of fluidization flow of cohesive micron size particles. The specific objectives of this research were: (1) Developing a cluster prediction mechanism applicable to Two-Fluid Modeling (TFM) of gas-solid systems (2) Developing more accurate drag models for Two-Fluid Modeling (TFM) of gas-solid fluidization flow with the presence of cohesive interparticle forces (3) using the developed model to explore the improvement of accuracy of TFM in simulation of fluidization flow of cohesive powders (4) Understanding the causes and influential factor which led to improvements and …

Passive Acoustic Emissions Monitoring Of Fluidized Bed Pellet Coating, Taylor Sheahan

Electronic Thesis and Dissertation Repository

Passive acoustic emissions were assessed for their potential as a non-invasive monitoring tool for the coating of pellets in a fluidized bed. Pharmaceutical pellets are small spherical particles that contain an active ingredient. They are film coated for the purpose of modified drug release and packed into capsules as a multiple unit dosage form. A more reliable monitoring and control method is desired to ensure the appropriate drug release profile is achieved by minimizing variations within and between coated pellets.

Microphones attached to the exterior of a conical top spray fluidized bed measured acoustic emissions produced from the coating process. …

Cluster Fluid Dynamics In Down Flow Reactors: Experimental And Modeling Study, Angel Virgilio Lanza Soto

Electronic Thesis and Dissertation Repository

Gas–solid concurrent downers possess unique features when compared to other gas–solid systems. Establishing their fluid dynamic properties requires both experimental measurements of gas-solid flow properties and computational modeling.

Measuring gas-solid flow properties such as cluster solid concentrations, individual cluster slip velocities, and cluster sizes, involves the use of specialized optical equipment, as well as a rigorous data analysis methodology. In addition, the modeling of the fluid dynamics of gas-solid flows in downer units offers special challenges such as establishing a proper drag model, cluster configuration and sizes, sphericity, boundary conditions, among other issues.

In this PhD dissertation, the fluid dynamics …

Selective Phenol Methylation To 2,6-Dimethylphenol In A Fluidized Bed Of Iron-Chromium Mixed Oxide Catalyst With O–Cresol Circulation, Witold Zukowski, Gabriela Berkowicz, Jerzy Baron, Stanisław Kandefer, Dariusz Jamanek, Stefan Szarlik, Zbigniew Wielgosz, Maria Zielecka

Witold Zukowski

Background 2,6-dimethylphenol (2,6-DMP) is a product of phenol methylation, especially important for the plastics industry. The process of phenol methylation in the gas phase is strongly exothermic. In order to ensure good temperature equalization in the catalyst bed, the process was carried out using a catalyst in the form of a fluidized bed - in particular, the commercial iron-chromium catalyst TZC-3/1. Results Synthesis of 2,6-dimethylphenol from phenol and methanol in fluidized bed of iron-chromium catalyst was carried out and the fluidization of the catalyst was examined. Stable state of fluidized bed of iron-chromium catalyst was achieved. The measured velocities allowed …

Low-Emission Combustion Of Alternative Solid Fuel In Fluidized Bed Reactor, Jerzy Baron, Beata Kowarska, Witold Zukowski

Witold Zukowski

No abstract provided.

Thermal Decomposition Of Selected Chlorinated Hydrocarbons During Gas Combustion In Fluidized Bed, Malgorzata Olek, Jerzy Baron, Witold Zukowski

Witold Zukowski

Background The process of thermal decomposition of dichloromethane (DCM) and chlorobenzene (MCB) during the combustion in an inert, bubbling fluidized bed, supported by LPG as auxiliary fuel, have been studied. The concentration profiles of C6H5CI, CH2Cl2, CO2, CO, NOx, COCl2, CHCl3, CH3Cl, C2H2, C6H6, CH4 in the flue gases were specified versus mean bed temperature. Results The role of preheating of gaseous mixture in fluidized bed prior to its ignition inside bubbles was identified as important factor for increase the degree of conversion of DCM and MCB in low bed temperature, in comparison to similar process in the tubular reactor. …

Incineration Of Municipal Sewage Sludge In A Fluidized Bed Reactor, Beata Kowarska, Jerzy Baron, Stanislaw Kandefer, Witold Zukowski

Witold Zukowski

In the present study reduction of nitrogen oxides using reburning technology, during combustion of sewage sludge (fuel I) and the mixture of sewage sludge, wasted bleaching earth and CaO (fuel II), was carried out. The experimental works were conducted in a laboratory-scale fluidized bed reactor (power up to 10 kW) with application of two types of beds: chemically inert bed (sand) and chemically active bed (CaO). The second combustion (reburning) zone in the reactor was formed by dosing into an area above the bed, additional gaseous fuel (propane). Obtained reduction in emissions of nitrogen oxides in both types of beds …

Investigation Of Gas-Solid Fluidized Bed With Non-Spherical Particles, Mario Alberto Ruvalcaba

Open Access Theses & Dissertations

The number of experimental and numerical studies of multiphase flows has remarkably increased over the last several years. This research has abundant applications in energy, chemical, and conversion processes. Common use of these technologies includes catalytic cracking for petroleum refineries, fluidized bed reactors (type of chemical reactor), interface modification, and has been an important technology breakthrough in coal gasification. The present work will concentrate on the investigation and validation of gas-solid flows utilizing numerical methods. The gas-solid flows study on this research assumes the solid and gas phases as continua with averaged properties.

The fluid flow computation was achieved using …

The Choice Of The Fraction Of Iron-Chromium Catalyst Powder Providing The Correct Fluidization Process, Jerzy Baron, Gabriela Berkowicz, Stanisław Kandefer, Witold Zukowski, Stefan Szarlik, Maria Zielecka, Wielgosz Zbigniew, Dariusz Jamanek

Witold Zukowski

Introduction

The synthesis in the fluid-bed catalytic reactor provides high efficiency by maximum use of surface of the catalyst. Iron-chromium catalyst is characterized by high activity and selectivity, that make it such an attractive bed for fluidized-bed reactor. The choice of the appropriate fraction of the catalyst is necessary to ensure a proper organization of fluid flow.

EXPERIMENTAL PART

The study involved three types of iron-chromium catalyst:catalysts DJ/6 and DJ/7 (are synthetized by Industrial Chemistry Research Institute in Warsaw) and TZC-3/1 catalyst (are produced in Zakłady Azotowe in Tarnowie -Moscicach S.A.). The studies also involved different fractions, which were obtained …

Low-Emission Combustion In A Fluidised Bed Reactor, Beata Kowarska, Jerzy Baron, Witold Zukowski, Jadwiga Zabaglo, Malgorzata Olek

Witold Zukowski

Regardless of the type of fuel and organization of the combustion process, usage of air as an oxidizer in this process is a source of nitrogen oxides emission. Significant increase in the emission occurs when fuel is itself a source of nitrogen. The nitrogen oxides formed in combustion processes, conducted in industrial processes, in power industry as well as in households pose a serious threat to the environment and human health when released to the atmosphere. Apart from solid fossil fuels, solid biomass is being increasingly used for energy purposes. However, it does contain significant amounts of nitrogen, usually exceeding …

Fibre-Optic Probe For The Simultaneous Measurement Of Gaseous Species Composition And Solids Volume Fraction, Jamal Chaouki, Jean-Philippe Laviolette, Gregory S. Patience

The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering

A novel infrared fibre-optic probe was developed to measure quantitatively and simultaneously solids volume fraction (1-E) and gaseous species composition (Yi) in a gas/solid fluidized bed. The fibre-optic probe was used with a FT-IR spectrometer to perform real-time and in-situ measurements of absorbance in the fluidized bed. The effect of (1-E) and Yi on the absorbance spectra were additive and could be independently calibrated. To calibrate the probe, fuel mole fractions and (1-E) were varied between 1.8 - 10.1 mol% and 0 - 0.45, respectively. A proof of concept for a novel application in fluidized beds was completed: the fibre-optic …

Hydrodynamic Characteristics Of Liquid-Solid Fluidization Of Binary Mixtures In Tapered Beds, Sankarshana Talapuru Dr, J S N Murthy, S Nandana, Phani Kiran S V G R, V Ramesh

The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering

The problems associated with fluidization in cylindrical beds like entrainment of particles, limitation of operating velocity could be overcome by adopting tapered beds. There have been no systematic studies reported on fluidization behavior of binary mixtures wherein the effect of size ratio is considered on the hydrodynamic characteristics of liquid-solid fluidization in tapered beds. In the present work, an attempt has been made to study the fluidization behavior and hydrodynamic characteristics of liquid-solid fluidization of binary mixtures of size ratios ranging from 1.2 to 5.13 using sand of different sizes in tapered beds of apex angles 50, 100 and 150. …

High Performance Computing: Clean Coal Gasifier Designs Using Hybrid Parallelization, Madhava Syamlal, C. Guenther, A. Gel, S Pannala

The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering

One of the targets for coal gasification in the near future is capturing 90% of the carbon with less than a 10% increase in cost of electricity. Aggressive goals like this will require innovative gasifier designs to reach the market place quickly, with less risk, and in an economically viable way. Researchers at the National Energy Technology Laboratory (NETL) are collaborating with industry, academia, and other national labs on multiphase computational models like the legacy code MFIX (Multiphase Flow with Interphase eXchange) which can help design, operate, and scale-up clean coal gasifiers to meet the challenges or a carbon constrained …

Numerical Computation Of Hydrodynamic Behavior Of Biomass Particles In Circulating Fluidized Beds, Afsin Gungor Dr.

The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering

A model using a particle based approach is developed to accurately predict the hydrodynamic behavior of biomass particles in CFBs. Generally, the change in the pressure gradient with height in CFB riser is small. Numerical results are in good agreement with experiments, both in form and magnitude.

Enhanced Fluidization Of Nanoparticle Agglomerates, Daniel Lepek

Dissertations

Gas fluidization of nanoparticle agglomerates has recently received much attention due to the excellent way in which these novel nanornaterials can be dispersed in a gaseous medium. Nanopowders have a very high surface area to volume ratio which allows them have unique chemical and physical properties especially at the surface. Fluidization is a popular technique for the continuous dispersal of solid materials in the fluidlike state.

Recently it has been found that nanoparticles exist in a highly agglomerate state which allow them to become fluidizable. The fluidization behavior of the nanopowders is dependent on the bulk and material properties of …

A New Fluid Dynamic Model For The Cfd Simulations Of Fluidized Beds, Luca Mazzei, Paola Lettieri

The 12th International Conference on Fluidization - New Horizons in Fluidization Engineering

A new Eulerian-Eulerian multidimensional model is proposed for the study of the dynamics of dense fluidized suspensions. The main distinctive feature of this new formulation of the equations of motion resides in the closure relationships adopted to express the fluid-particle interaction force. The force accounts for three contributions: buoyant force, drag force and elastic force. The buoyant force is related to the weight of the fluid displaced by the particles. The drag force is expressed as the product of the drag exerted on an unhindered particle, subject to the same volumetric flux of fluid, and a “corrective function” dependent on …

Gas Fluidization And Pneumatic Conveying In Confined Beds: A Numerical Study, Yurong He, Thang Ngoc Cong, Yulong Ding, Huilin Lu

The 12th International Conference on Fluidization - New Horizons in Fluidization Engineering

The fluidization phenomena for gas-fine particle two-phase flow is numerically simulated in confined fluidized bed based on two-fluid model, applying body-fitted coordination for the irregular geometry zone in this work. The simulation was performed either with a partially packed fluidized bed in the bottom part applying various superficial gas velocities in bubbling region, which is used to study the bubbles formation and the average porosity in the packed zone, or with a whole packed fluidized bed applying various solid flux rates in pneumatic region, which is used to investigate the mechanism in the packed bed. The void fraction of the …

Mechanistic Study Of Nano-Particle Fluidization, X. S. Wang, F. Rahman, Martin J Rhodes

The 12th International Conference on Fluidization - New Horizons in Fluidization Engineering

Degussa Aerosil R974 powder, with a primary particle size of 12 nm, was fluidized using nitrogen in a cylindrical vessel, 50-mm-id and 900 mm in height. Characteristics of incipient fluidization are analysed in relation to variations in the initial packing conditions. Bed collapse experiments were performed and the results are used for assessing fluidization characteristics of the particles. It was found that nanoparticles exhibit characteristics of both Group A and Group C powders. Various methods for estimating the cohesion forces between nanoparticle aggregates are discussed.

The Effect Of Vibrations On Fluidized Cohesive Powders, Diego Barletta, Giorgio Donsì, Giovanna Ferrari, Massimo Poletto, Paola Russo

The 12th International Conference on Fluidization - New Horizons in Fluidization Engineering

The fluidization of a cohesive silica powder has been tested with the help of mechanical vibration. The experiments showed how the effectiveness of vibrations changed with the vibrational acceleration and frequency. The aggregative behavior of powders has been highlighted and a model procedure is proposed to predict the aggregate size starting from the measurement of powder flow properties with conventional shear testers.

Simulation Of A Pulsating Bed Using Eulerian Approach, Shyam Shankar Dokka, Hamid Arastoopour

The 12th International Conference on Fluidization - New Horizons in Fluidization Engineering

A numerical study of the effect of gas pulsation on the flow pattern of solid particles in a two-dimensional gas-solid fluidized bed was conducted using the Eulerian granular kinetic theory. Our simulated bed dynamics agreed well with the experimental work of Koksal and Vural, and with the Discrete Element Method (DEM) model simulations of Tsuji et al.

An Explicit Method For The Packing Limit Management In Dense Gas-Solid Flow Cfd Simulations On Both Structured And Unstructured Grids, Alberto Passalacqua, Luca Marmo

Alberto Passalacqua

An explicit method for limiting the volume fraction of the dispersed phase in the CFD simulations of dense gas-solid flows is described and validated both on structured and unstructured computational grids. The procedure is based on the excess solids volume correction method proposed by Lettieri et al. (2003), which has been extended in this work to non-uniform grids made of cells having different shape and size. The method has been implemented in OpenFOAM and validated through the simulation of a fludised bed in which the superficial gas velocity has been reduced to a value close to zero.

Enhancement Of Fluidization And Filtration Using Nanoparticle Agglomerates And Aerogels, Jose A. Quevedo

Dissertations

Previous works have classified the fluidization behavior of nanoparticles as Agglomerate Particulate Fluidization (APF) and Agglomerate Bubbling Fluidization (ABE). These fluidization behaviors are quite different in regard to the fluidized bed expansion, the presence of bubbles and the smoothness of the bed surface, with APF nanopowders showing a much more homogeneous fluidization and a much better dispersion than ABE nanopowders which are generally very difficult to fluidize and show vigorous bubbling. In the present work, the fluidization of APF as well as ABF nanopowders is studied in depth, both conventionally, and in the presence of extemal assistance; several related topics …

Inverse Solid-Liquid Fluidization Of Aerogel Granules And Its Application In Removing Oil From Water, Gaurav Babubhai Patel

Theses

Fluidization is a very well known unit operation used in the chemical industry for various purposes. Inverse solid-liquid fluidization, where the solid particles to be fluidized are less dense than the fluid, is one of the several different kinds of fluidization being studied for its potential in industrial applications. The present work focuses on finding the hydrodynamic characteristics (minimum fluidization velocity, bed expansion and pressure drop) of an inverse fluidized bed of aerogel granules and using this system to remove oil from an oil-water mixture. The solid particles employed for this study are low density (100 kg/m³) surface …