Related Experiment Video
Updated: Jan 14, 2026
06:01
Frugal Imaging Technique of Capillary Flow Through Three-Dimensional Polymeric Printing Powders
Published on: October 4, 2022
1.7K
Improving the Fluidization Hydrodynamics of Cohesive Powder Using Pulsed Flow
Mohammad Asif1, Mourad M Boumaza1, Ebrahim H Al-Ghurabi1
1Department of Chemical Engineering, King Saud University, PO Box 800, Riyadh 11421, Saudi Arabia.
ACS Omega
|October 20, 2025
Summary
Square-wave pulsed flow improves the fluidization of cohesive fine powders like activated carbon. High-frequency pulsations significantly enhance stable operating ranges, overcoming issues caused by powder cohesiveness.
Area of Science:
- Chemical Engineering
- Powder Technology
- Fluid Dynamics
Background:
- Fine powders offer high surface area but suffer from poor fluidization due to cohesiveness.
- Cohesive powders lead to structural irregularities (cracks, channels), causing unpredictable fluidization and poor gas-solid mixing.
- Activated carbon, valued for adsorption, often presents fluidization challenges.
Purpose of the Study:
- To investigate the efficacy of square-wave pulsed flow in enhancing the fluidization of cohesive activated carbon powder.
- To assess the impact of varying pulsation frequencies on fluidization hydrodynamics.
Main Methods:
- Utilized square-wave pulsed flow with frequencies from 0.025 to 0.25 Hz.
- Analyzed pressure drop transients across the powder bed to evaluate fluidization behavior.
- Compared pulsed flow performance against conventional unassisted fluidization.
Main Results:
- Pulsed flow effectively delayed the formation of structural nonhomogeneities in the powder bed.
- The stable operating range for fluidization was extended up to four times with pulsed flow.
- Higher pulsation frequencies demonstrated superior performance in improving fluidization.
Conclusions:
- Square-wave pulsed flow is a viable method for enhancing the fluidization of highly cohesive powders.
- Pulsed flow offers a significant improvement over conventional fluidization for challenging materials like activated carbon.
- Optimizing pulsation frequency is key to maximizing the benefits of pulsed flow for industrial applications.
More Related Videos
Related Concept Videos
01:22Couette Flow
939
Couette flow represents the flow of fluid between two parallel plates, with one plate fixed and the other moving with a constant velocity. This configuration allows for a simplified analysis using the Navier-Stokes equations, which govern fluid motion under conditions of viscosity and incompressibility. For Couette flow, the assumptions include a steady, laminar, incompressible flow with a zero-pressure gradient in the flow direction. This flow type is beneficial for understanding shear-driven...
939
01:17Accelerating Fluids
2.1K
When a fluid is in constant acceleration, the pressure and buoyant force equations are modified. Suppose a beaker is placed in an elevator accelerating upward with a constant acceleration, a. In the beaker, assume there is a thin cylinder of height h with an infinitesimal cross-sectional area, ΔS.
The motion of the liquid within this infinitesimal cylinder is considered to obtain the pressure difference. Three vertical forces act on this liquid:
The motion of the liquid within this infinitesimal cylinder is considered to obtain the pressure difference. Three vertical forces act on this liquid:
2.1K
01:09Turbulent Flow: Problem Solving
380
Carbonation is a process used to dissolve carbon dioxide gas in a liquid, commonly used in the production of carbonated beverages. Achieving efficient carbonation requires careful control of temperature, pressure, and flow conditions. By adjusting these parameters, carbonation efficiency can be maximized, producing a higher concentration of CO2 in the liquid.
Temperature is a key factor in CO2 solubility. In this case, the CO2 gas and the liquid are cooled to 20°C. Lower temperatures enhance...
Temperature is a key factor in CO2 solubility. In this case, the CO2 gas and the liquid are cooled to 20°C. Lower temperatures enhance...
380
01:27Laminar Flow
2.1K
Laminar flow represents a smooth, orderly fluid motion where particles move along parallel paths, resulting in minimal mixing between layers. Streamlined particle paths characterize this flow regime and occur under conditions where viscous forces dominate over inertial forces. The distinction between laminar, transitional, and turbulent flow is primarily determined by the Reynolds number, a dimensionless quantity calculated as:
2.1K
01:23Steady, Laminar Flow in Circular Tubes
1.0K
Hagen-Poiseuille flow describes a viscous fluid's steady, incompressible flow through a cylindrical tube with a constant radius R. This flow profile is often applied to understand fluid transport in narrow channels, such as capillaries. It serves as a foundational example of laminar flow. In this model, cylindrical coordinates (r,θ,z) are used to describe the radial (r), angular (θ), and axial (z) dimensions within the tube. For Hagen-Poiseuille flow, the velocity profile is purely axial,...
1.0K
01:27Steady Flow of a Fluid Stream
664
Consider a control volume, such as a pipe with solid boundaries, through which fluid flows and changes direction due to the impulse exerted by the resulting force from the pipe walls. In steady flow, the mass of fluid entering the control volume at a given time, t, with velocity v1, is equal to the mass leaving after infinitesimal time dt, with velocity v2.
During this process, the momentum of the fluid within the control volume remains constant over the time interval dt. By applying the...
During this process, the momentum of the fluid within the control volume remains constant over the time interval dt. By applying the...
664