Spouted bed instabilities, such as spout deflection and oscillation, are well understood to decrease the particle recirculation rate, which decreases drying mixing efficiency. A recent study (Punch et al., Chem. Eng. J., 2024 495, 153459) showed that vertical vibration could be used instabilities in dry wet spouted beds at low height for large particles, without compromising rate. Here, we show experimentally can also reduce of particles with a inlet diameter ratio (>20), traditionally...

The descent of dense intruder disks through granular material fluidized by vertical gas flow and vibration is investigated experimentally computationally. Single intruders descend with a velocity which oscillates based on distance above the bottom system, simulations show due to spatially dependent void fraction in changing effective drag force intruder. Two vertically aligned undergo drafting-kissing-tumbling analog forms because decelerates particle compaction from weight top locked icon...

Abstract Structured bubbling with a triangular lattice pattern has been demonstrated previously to form in fluidized beds oscillated gas injection velocity. Here, we demonstrate using two‐fluid model simulations that dividing the distributor into slices and oscillating flow phase offset between consecutive enables structured wider range of bubble sizes configurations. Local particle solidification below bubbles leads formation these structures, as manifested high pressures simulations....

Significance The motion of granular materials, e.g., sand or catalytic particles, underlies many natural and industrial processes. Granular dynamics are difficult to understand model because transitions between solid-, liquid-, gas-like behavior, prior continuum models have struggled capture these transitions. Bubble-like voids normally rise chaotically through grains suspended by upward gas flow. We create structured bubble formations vibrating the system at a resonant frequency,...

Vladimir Bulović, Karen K. Gleason, and co-workers demonstrate monolithic fabrication of organic photovoltaic circuits directly on a variety common paper substrates using oxidative chemical vapor deposition to print conformal conductive polymer electrodes. The arrays produce >50 V, power electronic displays in ambient indoor lighting, can be tortuously flexed folded without loss function.

Granular materials are critical to many natural and industrial processes, yet the chaotic flow behavior makes granular dynamics difficult understand, model, control, causing difficulties for disaster mitigation as well scale-up optimization of devices. Hydrodynamic instabilities in externally excited grains often resemble those fluids, but have different underlying mechanisms, these provide a pathway understand geological patterns control flows industry. particles subject vibration been...

Vibration of gas-solid fluidized beds is often used to enable fluidization cohesive particles; however, it has also been shown reduce the minimum velocity (Umf). Here, we show via experiments that vibration can both Umf and bubbling (Umb) in Geldart Group B D particles. We observe reduced more than Umb, thereby creating a densely packed, bubble-free state when superficial gas between Umb. Umb decrease with increasing frequency amplitude results for across variety conditions could be plotted...

Abstract Bubble dynamics in gas fluidized beds are mathematically chaotic and difficult to predict. Various ways have been proposed the past alter overall bubble improve particular processes. In particular, it has shown that pulsed flow vibration can be used transform motion of bubbles into a dynamically structured pattern. The bubbling pattern does not change with system width, opening opportunities address key issues scaling up gas‐solids beds. However, only maintain for limited particle...

Two-fluid model (TFM) simulation predictions of bubble and particle dynamics in a 3D cylindrical fluidized bed are compared with magnetic resonance imaging (MRI) measurements from prior study across range gas velocities, sizes, heights. TFM simulations generally predict the number bubbles diameters seen as function vertical position well; however, speeds lower than those measured experimentally. The drag stress used were varied found to have an insignificant effect on but significant...

Granular particles subject to both vertical gas flow and vibration are shown experimentally exhibit structured convection cells in a densely packed yet fluidized state without voids traveling through the particles. Continuum gas-granular simulations reproduce phenomenon demonstrate that occurs due buoyant force arising from positive gradient bulk solid density competing with viscous created by interparticle friction. Simulations further show structures persist controllable manner when...

Abstract Predicting granular flow using continuum approaches is fundamental to advance physics and industrial applications. Previous studies have demonstrated that modeling can capture some hydrodynamic instability analogs in monodisperse materials. Recently, a family of gravitational instabilities was found between two types grains, including Rayleigh–Taylor analog, bubble rising, droplet splitting particle segregation. The high packing fraction bi‐disperse nature these flows allow for new...

Abstract Bubbling fluidized beds are often used to achieve a uniform particle temperature distribution in industrial processes involving gas and particles. However, the chaotic bubble dynamics pose significant challenges scale‐up. Recent work (Guo et al., 2021, PNAS 118, e2108647118) has shown that using vibration can structure bubbling pattern highly predictable manner with characteristic properties independent of system width, opening opportunities address key issues associated...

A study sheds light on the behavior of two interacting gas jets in a fluidized bed. Two regimes are identified: bubbles break off from either synchronous pattern or an alternating asynchronous pattern. Which forms depends separation distance between and particle size By reproducing magnetic resonance imaging results using simulations, is attributed to dominance drag forces over dissipative particles jets.

A contact-based method to evaluate mixing in a multicomponent system is proposed this work. The based on spatial contact frequency. One component contacting another more frequently space yields higher index. preliminary applications of quasi-2D binary experiment and 3D ternary simulation are presented. Detailed information Comparisons with other methods made, the advantages can be summarized by following: (i) it captures all behavior described listed work (ii) provides specific about which...