amiad DVF, Инструкции по установке, эксплуатации и обслуживанию, Страница: 11 / 42

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Air Scouring Process (optional add-on)
General Air Scour Benefits:
• Improve cleaning of media
• Minimize encrustation of media
• Reduce mudball formation
• Conserve backwash water
• Reduce wastewater discharge
•
Reduce filter down time
•
Save operator time & labor
• Extend periods between filter washes
• Increase filtration capacity
Incorporating Air Scour:
Air introduced anywhere below the steel plate floor (partition plate).
No air distribution piping is required.
An air supply pipe containing an isolation manual valve, regulator, pressure gauge and NRV allows the compressed air to
enter the bottom of each DVF filter unit below the distribution plate.
Design Guidelines for Air Scouring Supply:
• Consider the blower location, i.e. the height difference between the blower and the vessel air inlet. If the airline
is relatively long, calculate the dynamic head loss and take it in to account.
• An air valve MUST be installed to handle the blower air flow with the minimal hydraulic resistance (ARI D070P
model is recommended).
• A vacuum breaker MUST be installed on the drain line.
Process Description:
Partial Draining
This stage is designed to enable room on the upper part of the vessel for the air about to be introduced.
Close the inlet valve, outlet valve, BW inlet valve.
Open
the drain outlet valve, allowing the top amount of water in the DVF to drain up to the drain pipe level. The
draining time depends on the installation.
Air Scouring
The air scouring duration is usually set for 10 minutes at the recommended velocity of ~70 m/hr per m² vessel area at
0.5-0.6 bars.
During this process, hold the draining valve open to ensure easy draining of the air out of the vessel.
Bear in mind that by doing so, you take the risk of carrying out some media in case of draining failure.