Engineering

Backwash bath filtration

Equipment

• Candle filter
• Precoat tank
• Metering tank
• Metering pump, precoat pump
• Filtration additive

In Detail

The filtration additive is mixed with the filtered spin bath to form a homogeneous suspension. This suspension is fed by a precoat pump through the candle filter. The filtration additive forms a uniform precoat layer on the filter mesh of the filter cartridges, which acts as the actual filter media for the spin bath.

The liquid (backwash) to be filtered is then fed under pressure from the inside through the filter candles. During operation, the solids and filtration additive form a filter cake.

The filter is regenerated based on the differential pressure between the inlet and the outlet of the filter that is continuously monitored. For regeneration, filtration is stopped. The filter cake is removed.

Dry removal: Drying and removal of filter cake with compressed air at 4 bar.
While the filter cake must be handled manually, there is no problem in relation to wastewater contamination.

Wet removal: For wet removal, compressed air at 2 bar and a suitable wastewater treatment system is required.

The filter mesh must be cleaned with hot water and compressed air. Depending on the level of contamination, this process might need to be repeated several times. From time to time, the filter must be rinsed with detergent or caustic soda.