Industrial process centrifuges are used to separate, extract, or wash products or materials in continuous, batch, industrial or environmental operations. As their name suggests, these centrifugal separators use centrifugal force to separate solid particles from a liquid solution. Typically, this separation occurs because of the centrifugal force generated by the rotation of a centrifuge bowl. With industrial process centrifuges, solids are separated from liquids using high-speed gravity.
Many industrial processes use centrifugation to separate liquid phases and solids from each other. For example, industrial process centrifuges are often used to extract liquids from solid material in food, beverage, chemical, pharmaceutical, textile, and wastewater treatment processes. Industrial process centrifuges are also used at effluent treatment plants (ETP) that treat raw sewage coming from homes and businesses. ETPs use centrifugation to separate materials and produce clear water or effluent. Decanter industrial process centrifuges can be used for dewatering or thickening municipal or industrial sludge.
There are two main categories of centrifuges: standard centrifuges and hydrocyclones. Standard centrifuges separate particles from a solution according to particle size, shape, and density; the viscosity of the medium; and the rotor speed. The theoretical basis of this technique is the effect of gravity on particles (including macromolecules) in suspension. In response to gravity, two particles of different masses will settle in a tube. Centrifugal force (measured as xg, gravity) is used to increase this settling rate. As the force that an object moving in a circular path exerts on the object that constrains it, centrifugal force acts radially outward from the center of rotation.
Hydrocyclones are industrial process centrifuges that use centrifugal force to separate particulate elements of different sizes, shapes, and densities. The liquid to be filtered enters the hydrocyclone and begins a rotational flow pattern. The particles within this flow are subjected to centrifugal forces, are thus forced to the outside wall of the hydrocyclone. They then fall to the bottom, where they are discharged from the industrial process centrifuge. Specialized products such as ultracentrifugues are also available.
Based on particle size and density difference between liquid and solid phases, centrifugation separates material from liquid depending on the residence time within the industrial process centrifuges and the distance necessary for sedimentation. The efficiency of industrial process centrifuges depends on a solids volume fraction, effective clarifying surface, and an acceleration factor that depends on the amount of spinning revolutions and the radius of a rotor, water and wastewater, and food and pharmaceuticals.