Constant rate filtration

Constant rate filtration from https://www.particles.org.uk/filtration/

Constant rate filtration is a common particle separation technique used in particle technology, which involves the use of a porous filter medium to separate solid particles from a liquid or gas stream. The filtration rate remains constant during the process until the filter medium becomes clogged or saturated with particles, and the flow rate decreases.

The performance of constant rate filtration is influenced by several factors, including the properties of the filter medium (e.g., pore size, surface area, and permeability), the properties of the fluid (e.g., viscosity and density), and the properties of the particles (e.g., size, shape, and concentration).

During constant rate filtration, the liquid or gas stream containing the particles is passed through the filter medium under constant pressure or constant flow rate. The filter medium captures the particles that are larger than the pore size of the medium, while allowing the smaller particles and the fluid to pass through. The captured particles accumulate on the surface of the filter medium, forming a filter cake that increases the resistance to flow, and eventually leads to a decrease in the filtration rate.

To maintain a constant filtration rate, the filter medium needs to be cleaned or replaced periodically to remove the accumulated particles. The cleaning method depends on the type of filter medium and the nature of the particles. For example, in some cases, the filter medium can be backwashed or backflushed to remove the particles and restore the filtration rate.

Constant rate filtration is widely used in various industries, including water treatment, food and beverage processing, pharmaceuticals, and chemical processing, among others. It is a cost-effective and efficient method for separating particles from fluids or gases, and can be applied to a wide range of particle sizes and concentrations.