Bernoulli Automatic Self Cleaning Filter AF Seires for River Water Filtration​

Description

The AF Series Bernoulli Self-cleaning Filter ( AF Filter for short ) is designed for automatic continuous filtration of water in the pressurized systems. AF Filter removes debris and particles from natural water sources such as sea water or river water. It is the ideal solution for the coarse water filtration ranging from 200μm to 2000μm. The AF filter works in Bernoulli Effect Principle, which leads to the simple and reliable filtering operation. It cleans the filter screen with surface cross flow and the back-flushing flow, which brings higher particle removal efficiency than the conventional brush filter. Many particles larger than the screen aperture are extruded through the screen when a brush filter is brushing and cleaning.

The filter screen of AF Bernoulli Filter is back-flushed d by the cleaning disc inside, which is mounted on the piston rod driven by the pneumatic cylinder. When the cleaning action triggered, the disc moves into the filter screen and the water passes through the gap between the disc and the filter screen inner surface. Flow velocity is accelerated when the water passses the gap, while the static pressure around the gap is reduced because of the Bernoulli Effect Principle. Around the disc edge, the vacuum effect of lower static pressure back-flushes the filter screen inside surface with the filtered water.

Filter Screen

AF Bernoulli Filter mainly uses the slotted screen, which can be easily back-flushed clean and rarely get clogged. the slotted screen has the uniform and precise slots and very long service life. The filtration degree ranges 200μm to 2000 μm. 304, 316L, duplex 2205 are available for screen material. The 304 is ecomonic and suitable for the normal fresh water. the 316L is for the normal anti-corrosion request against the sea water. The duplex 2205 is the most ideal screen material for the long service life in the sea water.

The perforated screen is also vailable for the coarse filtration larger than 1000 μm if specially requested.

Working Principle

A disc moved by a piston generates high local increase in fl ow velocity between the fl ushing disc as it moves into the screen and the fi lter insert. The resulting drop in pressure gives contract-free cleaning of the screen and the particles escape via the fl ushing valve, which, when opened, creates a pressure difference with the working pressure, thus discharging the particles.

With its outstanding fl ow mechanics based design, the fi lter only generates a very low pressure drop in the system. The result is a considerable saving in energy in comparison to conventional so-called backfl ush fi lters. The quantities of fl ushing water are so small that systems can generally be operated without any additional investment in plant modifi cations. The fi lter comes supplied with an electronic multi-function unit, with monitoring of all functions and the facility for parameter adjustment and optimisation.

Equally, there is no problem in integrating and controlling the system using the customer’s own control devices (DCS) and monitoring systems.

Specifications:

Applications:

Typical Applications water treatment prefiltration, circulating cooling system, heat exchanger protection, spraying nozzle protection, ballast water treatment system, ultrafiltration membrane protection

Applicable Liquids underground water, sea water, lake water, river water, circulating cooling water, sewage water, process water, cleaning water

TECHNICAL FEATURES AND ADVANTAGES

■ Only two moving parts (the cleaning disc and the flushing valve )

■ Simple and reliable design structure, very easy to open for maintenance

■ Non-contact back-flushing cleaning, no particle larger than the screen aperture extruded through the filter screen

■ Consistant low pressure drop (<11Kpa) when the filter screen is clean or dirty

■ Very low working pressure requirement down to 30Kpa

■ Wide flowrate ranging from 30 to 3000 m3/ h with one single filter housing

■ No filtration interruption when back-flushing

■ Filtration degree ranges from 200μm to 2000μm

■ Flexible installation in the horizontal or vertical position

■ Equiped with differential pressure transmitter as d.p. instrument