Auto-self cleaning filters

TECHNI FILTRATION SPRL

Le Spécialiste en Filtration Industrielle

Auto-self cleaning filters

Self cleaning filters as their name suggests, are regenerated automatically. They therefore offer the advantage of not consuming filter media. However, their minimum cut off is limited at around 30-40 µm nominal. Different systems to backwash automatically the filter media exist.

Here below are two of them :

Here above a self-cleaning cartridge filter

Principle of operation of the filter of the preceding picture. When the differential pressure (11) becomes too high, the cartridge (3) rotates on itsel against a scraper(8) to backwash. Right : a section of the cartridge.

Principle of operation of previous filter. Here the discharging (7)is carried out against the current and continuously. A scraper (6) rotating unclogged the inner wall of the basket. Particles are then sucked towards the outlet flange (3).

Plate filter (Niagara)

The plate filter under pressure is a closed filtration system. Just as the self-cleaning filter it can be used with a wide range of adjuvants. However the finished product can be as well the cake as the filtrate.

The design of this type of filter would guarantee easy maintenance at low cost. It also offers the advantage there is not consuming or any filter media.

The vertical plate filter may be disposed as well in a horizontal or vertical housing. The discharge is manual on the horizontal filter while it's fully automated on the vertical housing through vibrations.

The filter plates are trimmed outside of several layers of stainless steel thin webs supported on the inside by a reinforcement to counter the pressure differential . The filtrate is diriged by a collector on which the plates are mounted.

The filter plates can also be arranged horizontally. In this case the cake discharging is done through a centrifugal force.

Herewith the four main principal steps of filtration (Niagara)

Candle filters

The candle filter is a fully automated and batch filter with filter elements arranged vertically in a pressure vessel. The candle filter is a compact plan with a large production capacity, allowing a dry extraction of the cake and also multiple treatments of the cake. Discharging of the cake is effected by help of an air pump which blows air in the opposite direction individually in each plug (backpulsing)

The removal of the cake is carried out through the bottom hopper of the filterhousing. The size of the outlet opening depends on the viscosity of the cake.

Smaller capacity and fully automated candle filters are also available.

Principle of operation of a candle filter : the liquid to be filtered passes trough the filter candles from the outside to the inside to be then collected into the collecting pipes.

Discharging of the cake is effected by help of an air pump which blows air in the opposite direction and individually in each plug. (backpulsing)