Pressure filter is the simplest batch-type filter with cloth filter baffle plate. Pressure filters are used to filter (thicken) suspensions and colloidal solutions for small-capacity manufacture.
Pressure filter is a vessel with double bottom. The upper false bottom (or grid) serves to keep the precoat and allows free passage of liquid to the low filter bottom. The suspension moves into the upper part of device (suspension receiver), the sediment remains on filter baffle plate, the liquid (filtrate) from the low part (filtrate receiver) is removed through the bottom connecting pipe.
The difference is in the operation under pressure. Nutsche filters have the pressure difference (moving force of filtering) less than 1 atm. The pressure filters have the pressure difference several atm. It allows fast and effective filtering of colloidal solutions and finely dispersed suspensions.
The productivity of pressure filter depends on surface of filter baffle plate, thickness of sediment layer, features of suspension and sediment, pressure difference. The advantage of pressure filters is the possibility to remove the most liquid from the sediment. As a result the liquid dilutes with wash water not much by the next elutriations. The disadvantages of pressure filters are the bulking of construction, hand-operated discharge of sediments, limited size of filter surface. To prepare the pressure filter for operating takes more time then nutsche filter because of necessity to seal the suspension receiver.
The pressure filters are manufactured by UralActiv Ltd. from polypropylene block copolymer or from other thermoplastic materials by agreement with the customer (polypropylene copolymer, polyvinyl chloride, HD polyethylene, polyvinylidene fluoride). The sealing of flange connections for case is made of silicone or fluoroplastic. It serves for leak proofness, reliable and secure operation of our devises. The construction of our filters is designed for each customer separately and allows to solve the most process problems. At customer's option the pressure filters can be equipped with wheels, grids to fix the cloth, inspection openings, and quick-release case with link bolts.