What is the mechanism behind the Fiber Filter Net filtration process?

The mechanism behind the filtration process of a Fiber Filter Net involves several physical processes that work together to capture particles or contaminants from a fluid (such as air or water). These processes include diffusion, interception, impaction, and adhesion. Here's a more detailed explanation of each mechanism:

Diffusion: Smaller particles in the fluid, especially those in the nanometer size range, exhibit random Brownian motion due to thermal energy. As these particles move through the filter net, they collide with the fibers. Some particles may become trapped when they collide with a fiber and stick to its surface due to molecular forces. Diffusion plays a significant role in capturing ultrafine particles.

Interception: Larger particles that are larger than the gaps between the fibers can be captured through the interception mechanism. As these particles move through the fluid and approach the fibers, they may come in contact with the fibers and be intercepted, much like a fly flying into a spider's web. The particle's trajectory is altered by the presence of the fiber, leading to capture.

Impaction: This mechanism is particularly effective for particles of larger size and higher momentum. When fluid flows through the filter net, particles with sufficient momentum continue along their path and collide with the fibers, where they get stuck. The particles are essentially "impacted" onto the fibers by the fluid flow.

Adhesion: Some particles might adhere to the fibers due to electrostatic forces or other attractive interactions. For example, if the filter fibers are charged or have a certain surface chemistry, they can attract and hold particles with opposite charges or complementary chemical properties.

Depth Filtration: A key feature of many fiber filter nets is depth filtration. This means that particles not only get trapped on the surface of the fibers but also penetrate into the depth of the filter matrix. The interconnected fibers create a maze-like structure that particles must navigate, increasing the chances of capture and preventing clogging.

Pore Size and Distribution: The size and distribution of the gaps or pores between the fibers play a critical role in determining what size of particles can be captured. Smaller pores will effectively capture smaller particles, while larger pores allow larger particles to pass through.

Flow Dynamics: The flow rate of the fluid passing through the filter net also influences the filtration process. A moderate flow rate allows sufficient contact time between particles and fibers, enhancing capture efficiency.

The combination of these mechanisms, along with the properties of the fibers used and the overall design of the filter net, determines its filtration efficiency and effectiveness. It's worth noting that filter nets are often designed to optimize specific mechanisms based on the intended application. For instance, some filters might be engineered to excel at capturing fine particulate matter, while others might prioritize larger particle capture or airflow capacity.