A Brief Introduction Of Vacuum Filtration
Vacuum filtration is one of the most widely used filtration methods in theory and practice. It is a method for dehydrating wastewater sludge by utilizing the pressure difference between the atmosphere and the vacuum.
As with other filter cake filtration methods, vacuum filtration techniques also use a porous filter media to support the filter cake. The difference is that vacuum filtration uses less propulsion and is, therefore, suitable for some special applications.
Vacuum filtration is a continuous filtration operation for sludge dewatering, typically done in a cylindrical drum filter. The filter medium covered on the drum may be a natural fabric, a synthetic fiber product or a wire mesh.
The drum is placed horizontally above the sludge tank and partially immersed in the tank. When the drum rotates slowly, a part of the circumference of the drum receives an internal vacuum, and the sludge is sucked onto the filter medium, the moisture in the sludge is sucked out during the rotation, and the dewatered cake is scraped off.
Usually, in order to achieve a good processing capacity of the vacuum filter, the wet sludge needs to be conditioned.