A filter press is commonly used in three applications: as a fixed volume, batch pressure filter; as a polishing filter to remove solids from a stream; and as a variable volume filter through a filter plate.
In operation, slurry is pumped under pressure into the press chambers through the manifold at the stationary head of the filter press. As each chamber fills with slurry, the liquid passes through the cloth medium, across the drain-field, through the drain ports and exits via gravity out of the corner discharge eyes.
The prime function of the filter media is to provide a porous support structure for the filter cake as it develops and builds. Initially, some solids may pass through the cloth media causing a slight turbidity in the filtrate, but gradually the larger particles within the slurry begin to bridge the openings in the media reducing the effective opening size. This allows smaller particles to bridge these reduced openings initiating the cake filtration process. Once a layer of solid particles achieves 1 to 2 mm in thickness, this “precoat” layer serves to separate out finer and finer particles as the cake builds in thickness, yielding a filtrate that is very low in turbidity.
Maintaining a clean environment, production of food and beverages, and development of essential medicines require filters that separate solids from liquids. ANDRITZ offers filter presses for a wide variety of applications and industries, ranging from treatment of wastewater sludge and drinking water, the food and beverage industry, the chemical industry, pharmacy and mining, to paper production. Applications include:
- chemicals and pigments
- metallurgical products and ores
- minerals and inorganic products/mining
- industrial and municipal wastewater treatment
- food and pharmaceuticals