Appendix, Hydrotech
Drumfilter
HPC
2.2
High
pressure
pump
The
HPC
system
shall
be
connected
to
a
high
pressure
pump
dimensioned
to
provide
8,2
l/min
at
80bar.
It
is
recommended
to
use
a
high
pressure
pump
with
possibility
to
adjust
the
pressure.
The
high
pressure
pump
is
not
included
in
the
HPC
system
as
standard
but
can
be
supplied
upon
request.
Remark:
Pressures
above
80
bar
will
cause
excessive
wear
on
the
filter
media.
2.3
Functional
description
Function:
The
HPC
system
is
designed
to
reduce
the
need
for
chemical
cleaning
of
the
filter
panels.
It
is
a
system
that
operates
at
maximum
80
bar
pressure.
Two
high
pressure
backwash
nozzles
clean
the
filter
media
during
rotation
of
the
filter
drum.
The
backwash
nozzles
are
assembled
on
a
backwash
pipe
mounted
on
a
slide
block.
The
slide
block
is
positioned
by
the
means
of
an
electrical
actuator.
The
system
is
equipped
with
a
back
pressure
valve
or
solenoid
valve
(optional)
to
prevent
flow
thru
the
spray
nozzles
when
the
system
is
in
standby
(applicable
when
a
pressurized
feed
system
is
used).
A
High
pressure
pump
(optional)
can
be
supplied
upon
request.
Backwash
sequence:
When
the
HPC
system
is
activated
the
filter
drum
starts
to
rotate.
The
high
pressure
pump
starts
and
pressurised
water
flow
thru
the
spray
nozzles
via
the
high
pressure
hose
and
back
pressure
valve.
For
systems
equipped
with
solenoid
valve
(optional),
the
valve
shall
open
prior
to
the
start
of
the
high
pressure
pump.
The
spray
nozzles
clean
one
section
of
the
filter
panels
during
rotation
of
the
filter
drum.
When
the
spray
nozzles
have
cleaned
the
current
filter
panel
section
on
the
filter
drum
for
one
revolution,
the
electrical
actuator
moves
to
its
outer
position
and
back
to
its
inner
position
again.
The
slide
block
has
now
moved
to
the
next
filter
panel
section
to
clean.
When
the
spray
nozzles
have
cleaned
this
filter
panel
section
on
the
filter
drum
for
one
revolution,
the
electrical
actuator
is
activated
again.
Then
this
procedure
is
repeated
until
the
whole
drum
has
been
cleaned.
The
high
pressure
pump
stops
followed
by
the
stop
of
the
drum
rotation.
For
systems
equipped
with
solenoid
valve
(optional)
the
solenoid
valve
closes
when
the
pressure
in
the
HPC
system
has
dropped,
followed
by
the
stop
of
the
drum
rotation.
Remark:
Installation
(electrical/mechanical)
and
use
of
the
included
components
must
follow
manufacturers’
recommendations
and
must
be
performed
by
authorized
personnel.
Local
regulations
must
be
followed.
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