A classifier is mechanical equipment used in wastewater treatment to separate and classify solids based on their size and shape. It is typically used in the primary treatment stage, after the bar screen chamber and grit chamber. The purpose of the classifier is to remove any remaining large solids or debris that may damage downstream equipment or interfere with the treatment process.
The classifier consists of a large tank or basin that allows the wastewater to settle. The wastewater is introduced at one end of the tank and allowed to flow slowly toward the other end. Along the way, the solids in the wastewater settle to the bottom of the tank while lighter materials such as grease and oil float to the surface.
To aid in the settling process, the wastewater may be treated with chemicals or polymers that help to clump the solids together and increase their settling velocity. As the solids settle to the bottom of the tank, they are removed by a rake or conveyor system and sent to a dewatering process or sludge treatment process.
Classifiers come in various designs and sizes, depending on the volume of wastewater being treated and the specific needs of the treatment plant. Some common types of classifiers include spiral classifiers, rake classifiers, and hydro cyclones.