Dehydration refers to the operation of mechanically removing the liquid portion remaining in the wet particle layer or the wet filter cake, and can be classified into gravity dehydration, centrifugal dehydration, aeration dehydration, and special dehydration. These dehydration methods are all related to the capillary in the layer of wetted particles. Centrifugal dehydration is not dry, but the pressurized liquid is used to remove the rising liquid in the capillary at normal temperature.

The special dehydration method is advantageous in that the hygroscopic fiber is formed into a felt layer to absorb moisture, a press dehydration method in which the layer of the fine particle is compressed and deformed to remove the contained liquid, and a method of increasing the dehydration effect by additionally applying vibration.

The resulting filter cake is filtered and subjected to heat drying for storage or use. It can be seen that the moisture content of the filter cake should be as low as possible before entering the drying chamber in order to reduce the heat energy consumption. Many dewatering filters have been developed for this purpose, such as drum vacuum filters equipped with roll-and-belt press dewatering units, chamber filter presses with press diaphragms, and barrels with press diaphragms. Filters and belt press filters.