INDION Automatic Valveless Gravity Filter

AVGF consists of a tank divided into three functional compartments, a backwash storage space, a filter bed compartment and a collection chamber under a false bottom. The backwash storage space is designed to hold the adequate amount of backwash water. The filter bed compartment normally contains standard fine filter sand supported on a collection system of disc type plastic strainers, which provide uniform collection of filtered water and uniform distribution of backwash water without the use of gravel. Standard filter sand or dual media (sand and anthracite) is generally used as the filter media. The AVGF can be built in cylindrical construction of steel or rectangular of concrete. The Standard Models are available in steel.

Working Principle

• Filtration
• Backwashing
• Rinsing

Features

• Automatic backwash, hence reliable.
• No need of manpower: as the filter operates automatically.
• No need of expensive valves, instrumentation, and backwash pumps and hence cost competitive.
• No moving parts, hence less maintenance.
• Uniform high quality treated water.
• No need of expensive power, hence low operating cost.
• Compact and modular design, hence low expansion and installation cost.
• Even though AVGF is automatic, the backwash can be initiated manually. However, external water source at 20 – 30 psi has to be provided.
• Space saving.

Applications

Ideal for Side Stream Filtration

In Side Stream Filtration the suspended solids will be very high in the beginning of operation, but with time (several days typically) it will drop significantly (usually below 20 ppm). The AVGF is widely used to reduce turbidity of cooling tower waters. This improves cooling tower efficiency and reduces maintenance and cleaning costs.

Treatment for portable water

Internationally AVGF is approved and used by majority of Municipal Corporations for treatment of potable water.

Polishing filter for Domestic sewage as well as industrial effluent

AVGF (Municipal type) can be incorporated as a polishing filter after secondary clarifier of the sewage/effluent treatment plant where usually load of less than 40ppm can be anticipated.