Shu-San Hsiau

National Central University | NCU · Department of Mechanical Engineering

The calcium looping process has become a promising technology for reducing carbon dioxide emissions because of its lower energy consumption compared with other methods. A three‐dimensional multifluid model based on the kinetic theory was employed to study the movement of granules in the calciner. The results demonstrated that an increase in the rot...

This paper develops a depth‐averaged theory to investigate submarine landslides and resulting water waves. The problems here consist of a pure fluid regime and a mixture regime of grains and fluid. Both regimes separate from one another by an interface, which is a material surface for grains. While the downslope velocities of the both phases are as...

The occurrence of slope disasters mainly depends on the terrain slope, size and amount of soil and rock particles, and the presence of heavy rain. If particles erode and entrain soil and rock in the bottom bed as they flow after the slope collapse, a massive avalanche can occur, threatening human life and causing substantial property damage. We emp...

Experiments were performed in an Couette ring shear cell with particles from the food industry of nearly spherical geometry and nominal diameters between 2.0 and 6.7 mm and with quartz grains with 2.1 to 3.3 mm diameter to examine whether rapid shear flow would give rise to an appreciable change in the granular properties. In particular, it was sus...

Background Granular bed filter technology is a newly emerging field, and the science is in its infancy. There is a lack of background information on these consistencies. This study provides new insights into clean processing, which is useful in hot gas cleanup technology. Methods We employed a moving granular bed filter, which is evaluated in two...

This study employed an experimental approach to investigate the effects of various filling degrees of the granular bed and the rotation speed on size-induced particle segregation behavior in an almost fully filled double-walled rotating drum. The distributions of the concentrations of bicolor particles in the system were obtained via image processi...

Since the dual fluidized bed (DFB) system has been increasingly adopted for waste‐to‐energy gasification, a three‐dimensional computational fluid dynamics full‐loop model of a DFB cold flow system has been developed to predict the pressure and sand circulation rate (SCR) under various operating conditions. The pressure data were recorded at 18 spec...

Optimizations of uniform velocities and residence times of oxygen carriers in chemical looping reactors are key factors. This study firstly applies inserts to improve the flow performance of Fe2O3 beads in an actual 3D reactor. This study proposes a novel DEM approach with null friction boundaries to investigate transport properties of Fe2O3 beads...

This study simplified a comprehensive multistep kinetic mechanism of fast biomass pyrolysis in a fluidized bed reactor (involving dense and dilute flows). A wide range of bioparticle sizes (0.2–2.0 mm) was investigated under four fluidization velocities (0.1–0.65 m/s). A multifluid model integrated with heterogeneous chemical reactions was develope...

In this study, we developed an improved comprehensive pyrolysis scheme by modifying the bio-oil species and gas species fractions, increasing the carbon fraction in the char, and combining and changing the metaplastic decompositions for energy analysis. The two-fluid model (TFM) framework was used to simulate pyrolysis in a two-dimensional tubular...

We propose a dust removal technology in which a two-stage moving granular bed filter was employed using coarse and fine filtering granules. The pressure drop, collection efficiency, and dust particulate size distributions were investigated using various mass flow rates for coarse and fine granules at room temperature. In addition, the ratio of mass...

From the understanding of dynamics and processes of rapid granular flows and the granular-segregation mechanism in gravity-driven flow, we can clarify the particle-composition structure in the downstream areas of avalanches in geophysical contexts, such as landslides, rock falls, and snow-slab avalanches. Such dynamics also provide a basis for geop...

The unsteady behaviors of the air-silica sand flow in a lab-scale dual fluidized bed gasification cold flow system have been studied. A two-dimensional computational fluid dynamics full-loop model with poly-size distribution in solid phases was developed as an innovation of this study to investigate the effects of crucial parameters on system hydro...

An unstable discharge rate occurs during dry fine powder discharge from a silo due to significant two–phase solid/gas interactions that occur in powder flows. In addition, the air bubble phenomenon may occur in a silo during fine powder discharge. The bubble dynamics seriously influence the fine powder discharge stability in the silo. Therefore, fo...

Numerical studies using Computational Fluid Dynamics (CFD) of thermal decomposition of Palm Kernel Shell (PKS) have been conducted in a fluidized bed reactor under atmospheric pressure of nitrogen as fluidization gas. To investigate the effect of temperature, the fast pyrolysis temperature was varied in a range from 400 °C to 650 °C. Furthermore, t...

In this study, we numerically investigate a pneumatic-conveying system for high-density metal powder via a gas-solid two-phase theory. This conveying system is modeled as a conveying pipeline in an additive-manufacturing (AM)-recycling system. The gas phase is set to nitrogen, and the solid-particle phase is set to be a nickel-superalloy material u...

High power generation efficiency and environmental performance are obtained in the integrated coal gasification combined cycle (IGCC) power plants. Hot gas clean-up is a key technology in IGCC systems. In this paper, a moving granular bed filter was constructed to examine the effect on collection efficiency when variations in the working parameters...

A two-dimensional computational fluid dynamics (CFD) multiphase flow model based on a laboratory-scale dual fluidized bed cold flow system has been developed to study the unsteady flow characteristics in that system. Different sizes of silica sand as multiple solid phases were simulated to thoroughly describe the actual sand flow, and hence enhance...

Size-induced granular segregation was performed systematically and experimentally in an almost fully filled double-walled rotating drum at 10 different rotation speeds and two different side wall types. The motion of the granular materials was recorded using a high-speed camera for image analysis of particle segregation development in the drum. Wit...

This study aims to reduce the severity of injuries caused by and the frequency of rear-end vehicle collisions. A better collision prediction method is proposed by means of millimeter-wave radar sensors able to rapidly detect potential collisions and alert drivers. Implementation of the system would bring about a reduction in accidents and potential...

This study presents a filtration technology, aiming to increase the efficiency of industry environment under different integrations and acquire the optimum solution. The goal of this study is to evaluate the performance of a moving granular bed filter designed to filter out coal fly ash. A series of experiments were performed at room temperature to...

Granular flows are constrained by applied stresses. When a granular flow moves rapidly and impinges on an obstacle, the stress is significantly increased along the contact force networks. Granular stresses are still incompletely understood. The aim of this study is to investigate a rapid avalanche of spherical glass beads in an inclined chute with...

We report on experiments we have performed using a rotating drum to investigate the core dynamics and transport properties of granular mixtures with different particle sizes and different fluid viscosities. We used six different fluid viscosities in the experiments, obtained using air and five different fluid mixtures of water and glycerin, and we...

We report the results of an experimental study on the thermal-diffusion mechanisms of particles with fluctuant motion in a dry granular system. Granular beds with different intensities of particle self-diffusion were produced by exerting vertical vibration-driving forces of different strengths. The effective thermal diffusivity, αe, was determined...

The integrated gasification combined cycle (IGCC) is considered a potentially important development in advanced coal-based power plants. In this system, gasification processes provide an opportunity to control and reduce pollutant emissions. Indeed, the clean utilization of flue gas is a key design requirement for new power plants. This study aimed...

Metalorganic chemical vapor deposition (MOCVD) is a critical process and is widely used for the epitaxial growth of light-emitting diode (LED) wafers. The key component, a gas injection system, delivers the gas into the reactor by using a nozzle or showerhead. In this paper, the numerical simulation method was applied to investigate the thermal flu...

Proton exchange membrane (PEM) water electrolysis systems offer several advantages over traditional technologies including higher energy efficiency, higher production rates, and more compact design. In this study, all the experiments were performed with a self-designed PEM electrolyser operated at 1 atm and 25oC. Two types of electrolyte were used:...

Since 1995, the residential sector has been a fast-growing energy consumption sector in Thailand. This sector contributes dramatically to the growth of Thailand’s electricity and oil demand. Our study analysed Thailand’s residential energy consumption characteristics and the seven underlying factors affecting the growth in energy use of five demogr...

The use of moving granular bed filters (MGBFs), which hold an important role in the gasification or combustion of coal and biomass, has been growing. Furthermore, these filters have great potential to be developed for the high-temperature gas cleanup of advanced power generation systems. However, the creation of a stagnant zone due to defective des...

Energy shortages and CO 2 emissions reductions are critical contemporary challenges for Thailand. A consumption-based analysis provides crucial information that enables policymakers to more comprehensively understand the hidden contributors of energy demand and CO 2 in the economy. The other manufacturing, construction and food and beverage sectors...

This study involved a comparison of production-and consumption-based analyses of energy consumption and CO 2 emissions between 2000 and 2010 in Thailand. The results revealed energy consumption contributor and CO 2 emitter based on consumption approach. The lowest energy-intensive (EI) sectors on production-based perspective, such as the 'other man...

This paper describes new design and test procedures of an inlet gas system that is part of a moving granular bed filter. A series of experiments is conducted to demonstrate the collection efficiency of this method under different operating conditions. In addition, the dynamic model and the flow analysis of gas in the inlet gas system and filter bed...

This study reports experimental findings on the sinking dynamics of a heavy granular ring caused by the density-driven segregation effect in sheared granular flows. Specifically, this study systematically investigates the influences of the density ratio, shear rate, and solid fraction of the granular material on the sinking behavior of a heavy gran...

This study focuses on investigating the mixing state by different mixing indices for different pre-organized particles. We also try to propose a new mixing index and discuss the advantages and disadvantages of different cases. The results show that the Avg. distance mixing index indicates the degree of mixing more accurately than other mixing indic...

Thailand has depended heavily on imported fossil fuels since the 1990s, which hindered the nation's economic development because it created uncertainty in the nation's fuel supply. An energy conservation policy was implemented in 1995 to require industries to reduce their energy intensity (EI) and consumption immediately. This study investigates th...

An international joint research project into advanced hot gas cleaning in high-efficiency coal and solid waste power generation processes using a granular bed filter has been developed. The goal of this study is to evaluate the filtration performance of a moving granular bed with baffle designs. A series of experiments are performed at room tempera...

The present study investigates the hydrodynamics and heat transfer phenomena that occur during the biomass fast pyrolysis process. A numerical approach that combines a two-dimensional Eulerian multi-fluid model and the kinetic theory of granular flow has been applied to simulate the gas-solid flow in a bubbling fluidized-bed reactor. In this study,...

The goal of this study is to evaluate the performance of a moving granular bed filter designed to filter out dust particles. We investigate the flow patterns of the filter granules, and the filtration efficiency under different inlet dust concentrations, but with a fixed filtration superficial velocity and mass flow rate of filter granules. All fil...

A core is formed at the center of a quasi-two-dimensional rotating drum filled more than half with granular material. The core rotates slightly faster than the drum (precession) and decreases in radius over time (erosion) due to the granular creeping motion that occurs below the freely flowing layer. This paper focuses on the effect of the surface...

The economy of Thailand has been growing rapidly since the 1980s. Consequent to the fast growth of the economy was a remarkable increase in energy consumption to the extent that domestic energy production was insufficient to cope with the energy demand. Therefore, Thailand's energy supply has relied on fossil fuel imports, which means greater insec...

We performed experiments to measure the dynamic properties of granular matter in a rotating drum device. The rotation speed, particle surface structure, and side wall condition were used as three experimental control parameters. The purpose was to quantify the effect of the internal friction of particles in both monodisperse and bidisperse granular...

We experimentally investigated the effects of interstitial fluid density and viscosity on density-induced granular segregation in a rotating drum. Image processing and a particle-tracking method were used for determining the segregation index and dynamic properties of granular materials. The results indicate that the interstitial fluid density has...

This study investigated the density-induced granular segregation phenomenon of wet granular materials in a quasi-2D rotating drum. The motions of the granular materials were recorded using a high-speed camera. Image-processing technology and the particle-tracking method were employed to measure the intensity of segregation, repose angle, and the ve...

Granular materials are common in daily life and in many industrial processes. Both fundamental research and industrial application studies are crucial for understanding the transport properties and segregation mechanisms of vibrating granular beds. One major related research topic is granular materials subjected to external vibration; such granular...

This paper proposes an exquisite confined compression experiment to validate a recently developed numerical method (Joint DEM–FEM approach). A uni-axial compression apparatus was designed to investigate the mechanical behaviour of a granular solid under vertical loading and the load transmission to the containing wall. This tester consists of an in...

Granular materials segregate because of differences in density, size, surface roughness, or shape, thus causing critical problems in many industries. In this study, we systematically and experimentally investigated the behavior of density-induced granular segregation in a circular thin rotating drum. We studied the effects of the density ratio, rot...

The cross-flow moving granular bed filter where the dust-laden gas passes horizontally through the granular layer and filter granules moves downwards and is removed at the bottom of the bed. It has the advantages of high filtration efficiency and lower pressure drop. The uniformity of gas flow is important for achieving a uniform gas distribution a...

In this study, we used a two-dimensional annular shear cell to systematically investigate the dynamic properties of granular flow when it is subjected to varying bottom wall friction coefficients. A particle tracking method and image processing technology were employed to measure tangential velocity, slip velocity, local solid fraction, and granula...

We describe the experimental measurements and discrete element simulations of steady rapid granular chute flows disturbed by a small fixed semi-cylindrical obstacle. The flow chute has a width of 5 cm, a length of 150 cm, an inclination of 30°, with an obstacle installed at approximately the center of the chute. The steady disturbed flow has a regi...

This study experimentally investigates the effect of a bumpy base on the Brazil-nut phenomenon in a vertically vibrated granular bed. The rise dynamics of an intruder is determined by the particle tracking method. The results indicate that the rise time increases with an increase in the base roughness, and the variation of the rise time with differ...

Granular mixtures may segregate because of external driving forces, which play an important role in industry and geophysics. We investigate experimentally the mechanism of density-driven spontaneous streak segregation patterns in a thin rotating drum. We find that a spontaneous streak segregation pattern can occur in such a system, which we call a...

We experimentally studied the influence of an intruder's friction coefficient and bed-filling height on the Brazil-nut effect in a quasi-2D vertical vibration granular bed. The motion of intruder was successfully measured using a high-speed camera and the rising time of intruder was determined by using a particle tracking method with the help of im...

Experiments were performed to measure the dynamic properties of granular matter in a slurry rotating drum. Five different fluid viscosities, including air and four different liquid viscosities with mixtures of water and glycerin, as well as three different particle densities were used in the experiments. In this study, the purpose was to quantify t...

This paper presents the study of the flow patterns inside a granular moving bed in a quasi-two-dimensional (2D) model of a granular moving bed filter (GMBF) vessel with vertical walls and a mass flow hopper. Fine quartz sand was chosen as the granular filter media in experiments. The related flow properties were measured by a Jenike Shear Tester. A...

This study investigates the dynamic properties of convection rolls in a 2D wet vibrated granular bed. A particle tracking method with the help of image-processing technology was used to measure the velocity fields, convection flow rate, and the granular temperatures in the wet vibrated granular bed. This study examines the dynamic behaviors of wet...

This paper proposes a discrete element method (DEM) model to simulate the convection phenomenon of non-spherical particles in a vibrating bed. The corresponding physical experiments were carried out in our previous study. The discrete element simulation results were validated with the experimental results. The non-spherical particles were paired pa...

A granular flow is normally comprised of a mixture of grain-particles (such as sand, gravel or rocks) of different sizes. In this study, dry granular flows are modeled utilizing a set of equations akin to a two-phase mixture system, in which the interstitial fluid is air. The resultant system of equations for a two-dimensional configuration include...

A compact two-stage granular moving-bed apparatus comprises a vessel, a flow-corrective element, and a filter material supplying part. The vessel comprises a hollow interior, a gas outlet, a first media outlet and a second media outlet. The flow-corrective element divides the hollow interior into a first channel and a second channel. The filter mat...

This study experimentally investigates the influence of intruder surface roughness in the Brazil nut effect in a quasi-two-dimensional vertical vibration granular bed. The intruder dynamics are determined using a particle-tracking method. The results show that surface roughness has a crucial role in the intruder rise dynamics; a rougher intruder ha...

Deflecting wedge obstacles are often built to divert hazardous flows away from residential areas that are in the way of harm. When a rapid avalanche flow is deflected by an obstacle, this usually causes abrupt changes in the flow thickness and velocity and exhibits characteristics like oblique shock waves in the aerodynamic system or oblique hydrau...

Granular materials may behave like a solid, a liquid, or a gas, depending on the processing conditions. In this study, a two-dimensional annular shear cell was used to investigate the dynamic properties of granular flow when subject to varying driving conditions. The effects of different driving conditions on granular flow were examined by taking i...

An experimental two-dimensional (2-D) thin slice panel for studying flow patterns of fine silica sand was designed and manufactured. As supplier of sand was not known at that time, flow properties of the silica sand were assessed without shear tests. A preliminary design of plane-flow hopper of the experimental 2-D panel was assumed to be close to...

Coal is a very important fuel since the supply of oil is quite limited, whereas coal is much more plentiful. The pressurized fluidized bed combustion (PFBC) and integrated gasification combined cycle (IGCC) systems are considered the best for advanced coal-fired power plants. However, the high temperature syngas produced by these systems contains m...

This paper presents an experimental validation of discrete element method (DEM) simulation for falling process of dry granular steps. Three chute slopes were considered in the study. The corresponding physical experiments were carried out in our previous study. The DEM simulations matched well with the experimental results regarding the external fl...

Using particle tracking velocimetry, we study the dynamic properties and flowing behavior of immersed granular matter in a rotating drum. In this study, the interstitial fluid is water or a water–glycerol mixture. The filling degree of the particles, the rotation speed, and the viscosity of the interstitial fluid are the three experimental control...

This paper presents an experimental validation of discrete element method (DEM) simulation for falling process of dry granular steps. Three chute slopes were considered in the study. The corresponding physical experiments were carried out in our previous study. The DEM simulations matched well with the experimental results regarding the external fl...

Silos are widely used for the industrial scale handling and transportation of powdered and granular materials. The process of discharging powder in a silo involves the flow of both solid particles and an interstitial fluid, usually air. In this study, we experimentally investigate the effects of particle size and ambient pressure on the discharge p...

We study the effects of interstitial fluid viscosity on the rates of dynamical processes in a thin rotating drum half-filled with monodisperse glass beads. The rotating speed is fixed at the rolling regime such that a continuously flowing layer of beads persists at the free surface. While the characteristic speed of a bead in the flowing layer decr...

The purpose of this study was to investigate the effects of different initial volume fill ratios of the granulator on granular agglomeration in a high-shear mixer. Calcium carbonate powders, with mean granule sizes of 75–150μm were used as the raw material. Polyethylene glycol 6000 (PEG 6000) was used as the melting binder. The initial liquid to so...

We performed experiments to measure the dynamic properties of wet granular matter in a rotating drum device. Four different amounts of liquid and rotation speeds were used in the experiments. The purpose was to quantify the effect of the cohesive force in the granular system. The results show that when only very small amounts of liquid were added,...

In this study, we detail a method for estimating the flux-averaged solid fraction of a steady granular flows moving down an inclined rectangular chute using velocity measurements from along the perimeter cross section, combined with knowledge of the mass flow rate through the cross section. The chute is 5cm wide and 150cm long with an adjustable in...

The Moving Granular Bed Filter (MGBF) is an important apparatus being developed for filtration of the hot gas. Our research group demonstrated a good solution to diminish stagnant zones in MGBF during the filtration process. However, there still remain some systematic problems that have to be worked out prior to commercializing a whole facility.The...

In this study, we have investigated experimentally the convection phenomenon of granular matter in a vertical shaker device. The motions of the granular materials were recorded by a high-speed camera. Image processing technology and a particle tracking method were employed to measure the convection strength, convection size, and granular temperatur...

Although the segregation of dry granular surface flow has been widely studied, cases where the air is completely replaced by a liquid still remain unexplored. In this study, we report on experiments performed to investigate the phenomena of particle segregation and flowing behavior in a rotating drum with liquids of different viscosities and differ...

The purpose of this study was to investigate the effects of the different surface properties of powders on granular agglomeration in a high-shear mixer. Polyethylene glycol 6000 (PEG 6000) was used as the melting binder. Three different powders, with mean granule sizes of 75–150μm were used as the raw materials: calcium carbonate, calcium sulfate,...

In this study, we carried out experiments to measure the electrostatic charge of a granular matter in a vertical shaker device. The purpose was to quantify the effect of the vibrating conditions on electrostatic charging in the granular matter. In each experimental run, 3 mm glass beads were first discharged to remove any residual charge prior to s...

The dominant mechanism affecting the flow behavior of granular materials is the random motions of particles that results from the interactive collisions between particles. The velocity fluctuations induce the segregation in granular flows. The different densities of granular materials with different filling layers and packing ratios were used to in...

This paper describes the design and testing of a trommel screen system for the separation of undersized particulates. The trommel screen system consisted of a cylindrical separation device that rotated to perform size separation. A series of experiments were carried out at room temperature to demonstrate the screening efficiency of this method unde...

A simplified theory is developed that yields the approximate stresses within a dust cake on the outer surface of ceramic candle filter and gives the critical factors which ensure complete detachment of cake. The radial and tangential stresses in cake during filtration have been derived by consideration of active state of stress in the dust cake. Ba...

Granular bed filter (GBF) technology can be applied for high-temperature gas cleanup in integrated gasification combined-cycle (IGCC) and pressurized fluidized-bed combustion (PFBC) advanced coal-fired power plants. The design of the gas inlet component of the granular bed filter is important to achieve a uniform gas distribution and higher usage r...

In recent years, Particle Tracking Velocimetry (PTV) has been extensively used to measure the translational velocity field of granular assemblies in applications such as vibrated beds, rotating drums and Couette shear cells. However, this technique has not yet been shown to be able to determine the velocity field of non-spherical particles. The aim...