Filter presses are classified according to their filtration driving force.

  Filters are classified into three categories based on the method of obtaining the filtration driving force: gravity filters, vacuum filters, and pressure filters.

  Gravity Filters

  These filters utilize the pressure created by the gravity and positional difference of the suspension on the filter medium as the driving force for filtration. They are generally operated intermittently, such as sand filters.

  Vacuum Filters

  These filters create negative pressure at the filtrate outlet as the driving force for filtration. The absolute pressure of the operating vacuum in industrial vacuum filters is (2.5–8.0) × 10⁵ Pa. The temperature of the suspension during filtration should be lower than the vaporization temperature of the filtrate under the operating vacuum. These filters are further divided into intermittent and continuous operation types.

  Pressure Filters

  These filters use pressure applied at the suspension inlet or mechanical pressing force applied to the wet material as the driving force for filtration. They are suitable for suspensions requiring a large pressure differential and are also divided into intermittent and continuous operation types. Intermittent tubular filter presses and pressure leaf filters are used for filtering low-concentration suspensions. Filter presses are also a type of intermittent pressure filter, and they are divided into three types: plate and frame, chamber and vertical. They have a wide range of applications.