Backwashing Air + Water (Optional With Air Blower); Rinse - Hayward FIBERPOOL Serie Guide De L'utilisateur

5.1.3. Backwashing air + water (optional with air blower)

We only recommend this type of backwashing process for those filters including nozzle plate. In that case, we
recommend:
The use of one or more blower pumps capable of reaching a scouring speed of 50 m³/h/m² inside the filter,
working within a range of pressure between 250 and 300 mbar, considering that the exerted pressure
together with air and water will never exceed 0.8 bar. The installation of the blower pumps will have a syphon
at the level of the highest point of the water level inside the filter, with a check valve to avoid the possibility
of any water going back to the blower pump. The additional losses of charge must be considered according
to the different accessories used.
The installation of an additional security valve to avoid exceeding the maximum working pressure indicated
in the curve of the blower pump that could damage either it or the filter.
The installation of a device capable of starting the pump progressively in order to avoid sudden variations in
pressure inside the filter, such as a variable speed drive, soft starter, etc.).
The entrance of the air by the battery of valves.
In any case an air compressor will be used to carry out this operation. It could seriously damage the filter.

5.1.4. Rinse

Rinse must be carried out immediately after backwash with the aim of removing the impurities that could have
entered in the collectors during the filter's backwash. This process will be performed following the steps below:
Stop the pump and set the valves in positions indicated in Fig. 7.1.
Start the pump and proceed to perform the rinse. The duration of the rinse is 3 minutes (according to
DIN 19643), to prevent impurities from appearing in the return line.
After the rinse, stop the pump and immediately set the valves in the Filtration position (Fig. 5.1).
To drain
5
3
1
4
2
From pump
(Fig. 7.1)
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