How does filtration work?

Filtration works by passing a mixture of fluid and solid particles through a porous material, known as a filter medium. The filter has tiny holes or pores that are small enough to block the solid particles but large enough to allow the fluid (liquid or gas) to pass through. This separation is primarily based on particle size. As the mixture flows through the filter, the solid particles get trapped on the surface or within the depth of the filter medium, forming a layer called the cake or residue. The fluid that passes through is called the filtrate. The driving force for filtration can be gravity, pressure, or vacuum suction. Gravity filtration is slow and relies on the weight of the liquid, while pressure or vacuum filtration speeds up the process by forcing the fluid through the filter more aggressively. Over time, the filter can become clogged with trapped particles, reducing its efficiency, which is why filters need to be cleaned or replaced regularly to maintain effective separation.