Structure and flow conditions through a colloidal packed bed formed under flow and confinement.

Area of Science:

• Colloid science
• Fluid dynamics
• Filtration technology

Background:

• Particle deposition and clogging are critical in filtration and industrial processes.
• Existing research often focuses on pore obstruction, not the subsequent particle accumulation.

Purpose of the Study:

• To investigate the dynamics and structural features of particle accumulation following pore obstruction.
• To determine the influence of confinement, ionic strength, and flow conditions on accumulation permeability and particle volume fraction.

Main Methods:

• Experimental analysis of colloidal suspension flow in constrictions.
• Varying confinement dimensions, ionic strength, and flow rates.
• Characterization of particle accumulation structure and flow behavior.

Main Results:

• High confinement leads to irreversible particle deposition, controlling accumulation structure and Darcy flow, regardless of other conditions.
• Ionic strength and flow conditions have a lesser impact in high confinement scenarios.
• Particles in the accumulation are fluid-supported and form a dense suspension of repulsive hard spheres, unlike the cohesive clog head.

Conclusions:

• Confinement is the dominant factor in particle accumulation structure and flow in constricted channels.
• The accumulation forms a distinct structure from the clog head, characterized by fluid-supported, repulsive particles.
• Understanding these dynamics is crucial for optimizing filtration and managing fouling processes.