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At least 19 records

Experimental Results for Large Particle Separation from Non-Newtonian Slurries Using Tapered Bump Arrays

Lateral displacement arrays are useful for separating particles such as blood cells and sand from carrier fluids. These arrays consist of staggered posts, which allow smaller particles to follow streamlines and larger particles to flow around the posts and migrate to one side. This migration increases the particle concentration in one direction and depletes the particle concentration in the other direction allowing particle separation to occur. Experiments were conducted to separate large particles in non-Newtonian yield stress slurries using tapered bump arrays. The non-Newtonian slurry used was composed of a bentonite kaolin blend with the inclusion of larger diameter particles. These experiments were conducted to evaluate the performance of particle separation using a tapered array of staggered posts as configured in a bump array for non-Newtonian yield stress slurries, an application that has not been explored experimentally. A theory for large particle separation was developed for slurries that exhibit Bingham or Cross rheology. The results of these experiments are described. This information could be applied in industrial settings such as separation of particles from nuclear waste slurries including those to be processed at the Hanford site, where removing large particles from waste streams is important to processing.

slurry, solids removal, deterministic lateral disp↗

Comparing Experimental Results for Large Particle Separation from Non-Newtonian Slurries Using Full and Tapered Bump Arrays

To separate particles from carrier fluids arrays of staggered posts inserted into the flow stream can be employed. The smaller particles follow the flow stream while the larger particles move laterally to one side. During flow, the concentration of particulate increases in one direction and decreases in the other crosswise direction. This technique separates the particles from the carrier fluid. Experiments using a slurry with non-Newtonian rheology were conducted to evaluate large particle separation from the non-Newtonian carrier fluid using bump arrays. The bentonite kaolin clay slurry with non-Newtonian rheology was spiked with large diameter inert glass particles. Experiments with flow through lateral displacement arrays evaluated the performance of particle separation using two array configurations: a full array with all posts and a tapered array with posts removed in a triangular portion of the array past the rows of anticipated particle of separation. The posts are staggered posts to promote particle segregation to one side of the flow channel. Using this type of array for removing particles from non-Newtonian yield stress slurries is novel and we present unique results. In this paper, the performance of full and tapered arrays are compared. These results have many industrial applications including removing particles from slurries of nuclear waste. Large particle removal is an important step in waste processing.

slurry, solids removal, deterministic lateral disp↗

Method and Apparatus for Separating Particles by Dielectrophoresis

Particle separation apparatus separate particles and particle populations using dielectrophoretic (DEP) forces generated by one or more pairs of electrically coupled electrodes separated by a gap. Particles suspended in a fluid are separated by DEP forces generated by the at least one electrode pair at the gap as they travel over a separation zone comprising the electrode pair. Selected particles are deflected relative to the flow of incoming particles by DEP forces that are affected by controlling applied potential, gap width, and the angle linear gaps with respect to fluid flow. The gap between an electrode pair may be a single, linear gap of constant gap, a single linear gap having variable width, or a be in the form of two or more linear gaps having constant or variable gap width having different angles with respect to one another and to the flow.

Pant, Kapil↗

Acoustic particle separation

A method is described which uses acoustic energy to separate particles of different sizes, densities, or the like. The method includes applying acoustic energy resonant to a chamber containing a liquid of gaseous medium to set up a standing wave pattern that includes a force potential well wherein particles within the well are urged towards the center, or position of minimum force potential. A group of particles to be separated is placed in the chamber, while a non-acoustic force such as gravity is applied, so that the particles separate with the larger or denser particles moving away from the center of the well to a position near its edge and progressively smaller lighter particles moving progressively closer to the center of the well. Particles are removed from different positions within the well, so that particles are separated according to the positions they occupy in the well.

Barmatz, M. B.↗

Experimental study of the application of rotating fluidized beds to particle separation

Rotating fluidized beds provide a unique opportunity to exploit fluidization under higher particle forces. The centripetal force in a rotating fluid bed is typically on the order of 10 times the force of gravity. Since the force keeping the particles in the unit is larger, the drag force can also be larger, allowing for higher gas and slip velocities. This operating regime provides intensified gas-solids contact through higher mass transfer, heat transfer, gas throughput, and bubble suppression. One application for using a rotating fluidized bed is in Chemical Looping Combustion (CLC). When solid fuels are used, oxygen carrier and ash are mixed in the process. In order to maintain high carbon capture efficiencies and recyclability of the oxygen carrier, the ash needs to be separated from the oxygen carrier. This separation can be done aerodynamically since the oxygen carrier is larger and heavier than the ash. It is theorized that rotating fluidized beds could improve both the gas-solid and solid-solid separation process efficiency and throughput as compared to conventional fluidized beds. A 43 cm diameter, 2.5 cm long vortex chamber has been designed and constructed to investigate the application to particle separation. A series of experiments have been performed to investigate the separation of different binary mixtures of solids. These experiments demonstrate the use of a rotating fluidized bed for high-G intensified particle separation that can be combined with high-G intensified gas-solids contact and gas-solids separation.¼

01 COAL, LIGNITE, AND PEAT↗

Volatile particles measured by vapor-particle separator

Vapor-Particle Separator (VPS) is a new technology developed for characterization of the volatile fraction of particulate matter in a combustion aerosol population. VPS incorporates a novel metallic membrane and operates in a cross-flow filtration mode for separation of vapor and solid (i.e. non-volatile) particles. Demonstration of the VPS technology on aircraft engine-emitted particles has led to the improvement of the technology and increased confidence on the robustness of its field performance. In this study, the performance of the VPS was evaluated against the Particle Measurement Programme (PMP) volatile particle remover (VPR), a standardized device used in heavy duty diesel engines for separation and characterization of non-volatile particulate matter. Using tetracontane particles in the laboratory reveals that the VPS performed reasonably well in removing the volatile species. In the field conditions, a single-mode particle size distribution was found for emitted particles from a T63 turboshaft engine at both idle and cruise engine power conditions. Removal of the volatile T63 engine particles by the VPS was consistent with that of PMP VPR. In tests on an F117 turbofan engine, the size distribution at the idle (4% rated) engine power condition was found to be bimodal, with the first mode consisting of particles smaller than 10nm, which are believed to be mostly semi-volatile particles, while the second mode of larger size was a mixture of semi-volatile and non-volatile particles. The distribution was single modal at the 33% rated engine power with no secondary mode observed. Altogether, for particles emitted by both engines, the removal efficiency of the VPS appears to surpass that of the PMP VPR by 8-10%.

42 ENGINEERING↗

Validation and optimization of batch and continuous particle separation processes

Recent advances in simulation capabilities coupled with advanced manufacturing can be leveraged to create highly efficient compact reactors with low emissions, low cost, high reliability, and high flexibility for energy conversion. This type of reactor is especially important for conversion of bio-mass, a storable, renewable and fast-growing energy source, considering the distributed nature of raw material and cost of biomass collection and transportation. To achieve this goal, it is critical to developing new process technologies that are significantly more efficient than traditional processes for which the added manufacture provides a fast way of realization and evaluation. Based upon the flagship MFiX multiphase computational fluid dynamic software suite, NETL has developed an Optimization Toolset to facilitate the CFD simulation based reactor design and optimization, and process intensification. This technical report presents the recent development and application of the Optimization Toolset and the framework for process optimization of particle separation in batch and continuous processes. In these processes, a fluidized bed reactor under proper operating condition was used to separate particles of different physical properties. MFiX-DEM simulations were conducted for a batch system to simulate the process covering a wide range of superficial gas velocities from which the optimal operational parameter can be determined through analyzing the system response. After successful demonstration of the framework, a continuous system for particle separation was designed based on CFD simulations. Similar optimization exercises were conducted for the continuous particle separation considering multiple operating parameters. The design was then fabricated in the laboratory through 3D printing for testing. The particle separation performance was carefully measured through high-speed video for particle tracking. Quantitative comparison between numerical results and experimental measurements were conducted for confirmation and validation.

30 DIRECT ENERGY CONVERSION↗

LARGE PARTICLE SEPARATION FROM NON-NEWTONIAN SLURRIES USING BUMP ARRAYS

Here we evaluate the performance of bump arrays to separate large particles from non-Newtonian slurries with Bingham and Cross rheology. Bump arrays in deterministic lateral displacement devices separate large particles from small particles using arrays of staggered posts. Large particles, defined as those with radii larger than the distance between the edge of a post and the stagnation streamline from the next downstream post, must bump toward one side of the device, whereas particles smaller than this distance slalom from entrance to exit. Although these devices have been used to separate a wide variety of large particles from blood cells to sand, partition of large particles from non-Newtonian fluids remains unexplored. Yet, an important set of modestly concentrated slurries, including Hanford nuclear waste, displays non-Newtonian rheology. Here we evaluate the influence of non-Newtonian rheology on the large-small particle size cutoff in bump arrays using a model that explores the influence of yield stresses, ratios of zero and infinite shear viscosities, and Cross’s exponent under strictly laminar well-developed conditions. Surprisingly, we find that viscosity ratios and Cross’s exponent make no significant difference on the particle cutoffs between large particles that bump and small particles that slalom around the posts from entrance to exit. In contrast, we find that yield stresses do significantly affect the size cutoff. As the yield stress increases, the velocity profiles become more plug like lowering the size cutoff. For nuclear waste separations where removing large particles is a priority, increasing yield stresses is conservative.

slurry, solids removal, deterministic later displa↗

Can Bump Arrays Separate Particles from Turbulent Flows?

In this paper, we evaluate the hypothesis that bump arrays can be used to separate particles from turbulent flows entering the array. Microfluidic bump arrays are known for separating particles by size from laminar inlet flows. However, turbulent inlet flows have not been explored but become important as microfluidic bump arrays are scaled up to mesofluidic bump arrays. We find experimentally that particle separation is indeed effective at higher Reynolds numbers. These experimental findings portend industrial scale particle separation due to the higher flow rates they facilitate.

Pease, Leonard F.↗

Lunar Soil Particle Separator

The Lunar Soil Particle Separator (LSPS) beneficiates soil prior to in situ resource utilization (ISRU). It can improve ISRU oxygen yield by boosting the concentration of ilmenite, or other iron-oxide-bearing materials found in lunar soils, which can substantially reduce hydrogen reduction reactor size, as well as drastically decreasing the power input required for soil heating

Berggren, Mark↗

Apparatus for separating particles utilizing engineered acoustic contrast capture particles

An apparatus for separating particles from a medium includes a capillary defining a flow path therein that is in fluid communication with a medium source. The medium source includes engineered acoustic contrast capture particle having a predetermined acoustic contrast. The apparatus includes a vibration generator that is operable to produce at least one acoustic field within the flow path. The acoustic field produces a force potential minima for positive acoustic contrast particles and a force potential minima for negative acoustic contrast particles in the flow path and drives the engineered acoustic contrast capture particles to either the force potential minima for positive acoustic contrast particles or the force potential minima for negative acoustic contrast particles.

42 ENGINEERING↗

Apparatus for separating particles utilizing engineered acoustic contrast capture particles

An apparatus for separating particles from a medium includes a capillary defining a flow path therein that is in fluid communication with a medium source. The medium source includes engineered acoustic contrast capture particle having a predetermined acoustic contrast. The apparatus includes a vibration generator that is operable to produce at least one acoustic field within the flow path. The acoustic field produces a force potential minima for positive acoustic contrast particles and a force potential minima for negative acoustic contrast particles in the flow path and drives the engineered acoustic contrast capture particles to either the force potential minima for positive acoustic contrast particles or the force potential minima for negative acoustic contrast particles.

59 BASIC BIOLOGICAL SCIENCES↗

Systems and methods for separating particles utilizing engineered acoustic contrast capture particles

An apparatus for separating particles from a medium includes a capillary defining a flow path therein that is in fluid communication with a medium source. The medium source includes engineered acoustic contrast capture particle having a predetermined acoustic contrast. The apparatus includes a vibration generator that is operable to produce at least one acoustic field within the flow path. The acoustic field produces a force potential minima for positive acoustic contrast particles and a force potential minima for negative acoustic contrast particles in the flow path and drives the engineered acoustic contrast capture particles to either the force potential minima for positive acoustic contrast particles or the force potential minima for negative acoustic contrast particles.

54 ENVIRONMENTAL SCIENCES↗

Coil planet centrifugation as a means for small particle separation

The coil planet centrifuge uses a centrifugal force field to provide separation of particles based on differences in sedimentation rates by flow through a rotating coiled tube. Three main separations are considered: (1) single phase fresh sheep and human erythrocytes, (2) single phase fixed heep and human erythrocytes, and (3) electrophoretically enhanced single phase fresh sheep and human erythrocytes.

Herrmann, F. T.↗

Particle Separator for Improved Flameless Pressurized Oxy-Combustion

The team of Southwest Research Institute® (SwRI®), ITEA, Electric Power Research Institute, Inc. (EPRI), and General Electric Global Research (GE) is advancing Flameless Pressurized Oxy-combustion (FPO), a novel coal technology. This effort seeks to develop a particle separator for the hot-gas stream leaving the FPO loop. In order to maximize the energy extracted from the cycle, the hot gas is put through a turbo-expander before flue-gas treatment. The particle separator designed under this project sought to operate at high temperature and with low-pressure drop, protecting the turbo-expander from erosion damage. The team engaged potential vendors for the test, developed plans for the pilot test loop modification, and refined requirements for the commercial turbo-expander.

01 COAL, LIGNITE, AND PEAT↗

Systems and methods for separating particles and/or substances from a sample fluid

Systems and methods for separating particles and/or toxins from a sample fluid. A method according to one embodiment comprises simultaneously passing a sample fluid and a buffer fluid through a chamber such that a fluidic interface is formed between the sample fluid and the buffer fluid as the fluids pass through the chamber, the sample fluid having particles of interest therein; applying a force to the fluids for urging the particles of interest to pass through the interface into the buffer fluid; and substantially separating the buffer fluid from the sample fluid.

59 BASIC BIOLOGICAL SCIENCES↗

Vapor-Particle Separation Using Microporous Metallic Membrane in Crossflow Filtration

Simultaneous separation of vapor and particles in industrial processes could be a key step toward manufacturing of high-quality goods. The separation is critical for successful measurement of volatile or semi-volatile aerosol particles, which no reliable technique exists. We have developed a technique for separation of vapor and particles simultaneously using a specialty microporous metallic membrane. The separator allows the thermally denuded particles traverse straight through the membrane tube, while the vapor molecules permeate through the membrane, separate from the particles and are removed subsequently. The separation technique virtually eliminates the possibility of contamination by vapor re- condensation. We tested the prototype of the vapor-particle separator (VPS) using aerosols prepared from sodium chloride to represent non-volatile aerosols. Chemical like dioctyl phthalate was chosen to represent volatile particles. The test aerosol particles were generated by an atomizer followed by a tandem differential mobility analyser to produce a stream of monodisperse particles in the size range of 10 to 100 nm. In real world particles, we tested the VPS using diesel engine particles that is a mixture of complex chemical composition. Number concentration of the nonvolatile particles reduced as the temperature increased, but the mode diameter of the aerosol population remained unchanged. Number concentration of the volatile particles was also reduced as the temperature increased, but their mode diameters became smaller as particles shrunk in diameter. Differences in the thermal behaviour of the particles were attributed to its transition energy barrier and evaporation rate. Mass balance analysis suggests the separation of vapor and test particles was reasonably complete. Thus, we conclude the VPS could provide an effective means for quantitative characterization of aerosol volatility and separation of vapors from particles.

aerosol↗

Particle separation

Embodiments of a method for selecting particles, such as based on their morphology, is disclosed. In a particular example, the particles are charged and acquire different amounts of charge, or have different charge distributions, based on their morphology. The particles are then sorted based on their flow properties. In a specific example, the particles are sorted using a differential mobility analyzer, which sorts particles, at least in part, based on their electrical mobility. Given a population of particles with similar electrical mobilities, the disclosed process can be used to sort particles based on the net charge carried by the particle, and thus, given the relationship between charge and morphology, separate the particles based on their morphology.

Moosmuller, Hans↗