Operational Mechanics - Pentair PR AQUA ROTOFILTER Installation And Operation Manual

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SECTION 4: INTRODUCTION

4.3 Operational Mechanics

Microscreen drum filters operate under the principle
of a mechanical sieve. Untreated water is fed to the
inside of a drum housed in an enclosure. The drum
has fine screens mounted to its periphery. Gravity
causes the water to flow through the screens, while
suspended solids within the water adhere to the
screen surface. The filtered water then flows out of
the enclosure by gravity.
In Ultraviolet (RFUV) models, the filtered water
passes through a chamber containing a series of
UV modules, each sized to deliver a specific UV
dose for disinfection, prior to exiting the enclosure.
The water level inside the drum rises as solids
collect on the screen surface and obscure the
screen pores. When the water level reaches a
contact switch, the drum begins to rotate, and a
backwash spray system is started.
The backwash spray system washes the solids
from the screens into a separate trough inside the
drum. The solids flow from the trough by gravity for
disposal or recovery.
Clean screens are rotated into the water, and the
water level falls. The backwash spray system shuts
down once the screens are clean. In the event
of a backwash system failure, the Rotofilter has
integrated overflow protection that allows water
to bypass the screens and flow directly into the
enclosure, rather than backup into the waste trough
and inlet supply.
PR Aqua Rotofilter Drum Filter Installation and Operation Manual
™
The potential treatment capacity of the Rotofilter
depends on the flow rate, solids concentration of
the water, and the pore size of the microscreen.
UV transmittance of the water is also a factor for
Ultraviolet (RFUV) models.
The Rotofilter operates in Automatic Mode or
Manual Mode. When in Automatic Mode, the
backwash system and drum rotation turn on
automatically when a high-level float switch reaches
a predetermined position. Once the drum has been
sufficiently cleaned, the backwash system and
drum rotation automatically shut off.
When in Manual Mode, the backwash system and
drum rotation are always on.