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Changing the flocculator
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h1. Changing the flocculator {composition-setup} cloak.toggle.exclusive=false {composition-setup} h2. |
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{toggle-cloak:id=Concerns} |
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Concerns {cloak:id=Concerns) } |
The
...
Tube
...
Floc
...
research
...
team
...
has
...
known
...
for
...
a
...
while
...
now
...
that
...
sedimentation
...
was
...
occurring
...
within
...
the
...
flocculator
...
and
...
that
...
such
...
premature
...
sedimentation
...
was
...
bad.
...
The
...
switch
...
from
...
a
...
horizontally
...
coiled
...
flocculator
...
to
...
a
...
vertically
...
coiled
...
one
...
was
...
made
...
partly
...
to
...
try
...
to
...
overcome
...
this
...
issue.
...
Throughout
...
the
...
Fall
...
2007
...
semester,
...
the
...
Lab
...
Floc
...
team
...
performed
...
numerous
...
experiments
...
with
...
the
...
flocculator
...
apparatus
...
despite
...
not
...
having
...
completely
...
eliminated
...
sedimentation.
...
It
...
seemed,
...
at
...
the
...
time,
...
that
...
the
...
sedimentation
...
accrued
...
per
...
run
...
was
...
minimal
...
and
...
that
...
it
...
would
...
not
...
contribute
...
a
...
significant
...
amount
...
of
...
error
...
into
...
our
...
measurements.
...
Further
...
investigation
...
by
...
the
...
Lab
...
Floc
...
team
...
this
...
semester,
...
however,
...
has
...
given
...
new
...
light
...
into
...
the
...
significance
...
of
...
this
...
premature
...
sedimentation
...
as
...
well
...
as
...
a
...
new
...
problem
...
of
...
fluid
...
circulation
...
inside
...
the
...
settling
...
column
...
immediate
...
after
...
the
...
termination
...
of
...
flow
...
through
...
the
...
apparatus.
...
These
...
issues
...
are
...
significant
...
not
...
only
...
because
...
they
...
are
...
unexpected
...
and
...
are
...
not
...
optimal
...
experimental
...
conditions,
...
but
...
they
...
also
...
put
...
into
...
question
...
the
...
validity
...
of
...
the
...
data
...
obtained
...
last
...
semester
...
and
...
the
...
method
...
by
...
which
...
we
...
have
...
been
...
analyzing
...
and
...
describing
...
these
...
past
...
results.
...
Below
...
are
...
more
...
detailed
...
discussions
...
of
...
the
...
different
...
aspects
...
of
...
these
...
problems.
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{cloak} h3. |
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{toggle-cloak:id=Issues with premature sedimentation} |
...
...
with
...
premature sedimentation
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sedimentation {cloak:id=Issues with premature sedimentation} |
We
...
have
...
hypothesized
...
that
...
because
...
our
...
experimental
...
apparatus
...
is
...
currently
...
limited
...
to
...
generating
...
Poiseuille
...
flows,
...
there
...
are
...
no
...
transverse
...
velocities
...
with
...
respect
...
to
...
the
...
streamlines
...
of
...
the
...
flow
...
strong
...
enough
...
to
...
keep
...
large
...
flocs
...
in
...
suspension
...
once
...
they
...
are
...
large
...
enough
...
to
...
settle
...
out.
...
Therefore,
...
large
...
flocs
...
are
...
settling
...
out
...
on
...
the
...
bottom
...
walls
...
of
...
the
...
tubes
...
where
...
the
...
streamline
...
velocity
...
is
...
at
...
a
...
minimum
...
and
...
where
...
there
...
are
...
negligible
...
velocities
...
normal
...
to
...
the
...
wall
...
to
...
scour
...
the
...
flocs
...
back
...
towards
...
the
...
center
...
of
...
the
...
pipe.
...
There
...
are
...
several
...
reasons
...
why
...
this
...
is
...
unwanted:
...
- If
...
- flocs
...
- are
...
- settling
...
- out,
...
- they
...
- are
...
- not
...
- making
...
- it
...
- out
...
- of
...
- the
...
- flocculator
...
- and
...
- we
...
- loose
...
- information
...
- about
...
- the
...
- performance
...
- of
...
- our
...
- flocculator.
...
- Since
...
- we
...
- are
...
- interested
...
- in
...
- how
...
- shear/strain
...
- affects
...
- floc
...
- size
...
- and
...
- the
...
- final
...
- clarity
...
- of
...
- the
...
- water,
...
- we
...
- need
...
- the
...
- flocs
...
- to
...
- stay
...
- in
...
- suspension
...
- so
...
- we
...
- can
...
- measure
...
- how
...
- well
...
- they
...
- were
...
- formed.
...
- With
...
- significant
...
- premature
...
- sedimentation,
...
- the
...
- measurements
...
- of
...
- final
...
- settling
...
- effluent
...
- turbidity
...
- clearly
...
- underestimates
...
- flocculation
...
- performance.
...
- Not
...
- only
...
- does
...
- premature
...
- settling
...
- underestimate
...
- flocculation,
...
- but
...
- it
...
- also
...
- makes
...
- determining
...
- how
...
- parameters
...
- like
...
- flow
...
- rate
...
- (and
...
- other
...
- measurements
...
- of
...
- shear
...
- and
...
- strain)
...
- have
...
- affected
...
- flocculation.
...
- For
...
- instance,
...
- it
...
- is
...
- nearly
...
- impossible
...
- to
...
- determine
...
- for
...
- certain
...
- whether
...
- the
...
- steeper
...
- settling
...
- curves
...
- at
...
- higher
...
- flow
...
- rates
...
- was
...
- a
...
- result
...
- of
...
- larger
...
- flocs
...
- being
...
- formed
...
- or
...
- whether
...
- the
...
- higher
...
- flow
...
- rate
...
- just
...
- kept
...
- more
...
- flocs
...
- in
...
- suspension
...
- and
...
- thus
...
- was
...
- able
...
- to
...
- settle
...
- out
...
- faster.
...
- The
...
- efficiency
...
- of
...
- the
...
- flocculator
...
- is
...
- compromised
...
- when
...
- big
...
- flocs
...
- settle
...
- out
...
- because
...
- the
...
- primary
...
- mechanism
...
- by
...
- which
...
- fine
...
- particles
...
- are
...
- removed
...
- from
...
- solution
...
- is
...
- adsorption
...
- onto
...
- large
...
- flocs.
...
- The
...
- poor
...
- final
...
- turbidity
...
- observed
...
- in
...
- our
...
- experiments
...
- may
...
- be
...
- due
...
- to
...
- too
...
- many
...
- large
...
- flocs
...
- settling
...
- out
...
- of
...
- the
...
- flow
...
- before
...
- they
...
- reach
...
- the
...
- end
...
- of
...
- the
...
- flocculator.
...
Wiki Markup {cloak}
...
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{toggle-cloak:id=Options for fixing premature sedimentation} |
...
...
for
...
fixing
...
premature sedimentation
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sedimentation {cloak:id=Options for fixing premature sedimentation} * |
A
...
new
...
observation
...
:
...
While
...
sedimentation
...
may
...
happen
...
during
...
the
...
loading
...
state,
...
much
...
of
...
the
...
settling
...
in
...
the
...
flocculator
...
is
...
permitted
...
to
...
happen
...
during
...
the
...
sedimentation
...
state,
...
when
...
the
...
flow
...
is
...
shut
...
off
...
to
...
allow
...
sedimentation
...
in
...
the
...
settling
...
column.
...
Since
...
there
...
are
...
flocs
...
present
...
in
...
the
...
flocculator
...
during
...
this
...
settle
...
state
...
(which
...
usually
...
as
...
a
...
10
...
minute
...
duration,)
...
those
...
flocs
...
will
...
settle
...
out
...
into
...
the
...
bottom
...
walls
...
of
...
the
...
flocculator.
...
Additionally,
...
since
...
the
...
flow
...
during
...
the
...
clean
...
flocculator
...
phase
...
is
...
not
...
turbulent,
...
the
...
majority
...
of
...
settled
...
flocs
...
do
...
not
...
get
...
resuspended
...
into
...
the
...
flow
...
and
...
washed
...
out
...
of
...
the
...
flocculator.
...
As
...
these
...
sediments
...
continue
...
to
...
build
...
up
...
over
...
each
...
experimental
...
run,
...
it
...
is
...
difficult
...
to
...
determine
...
if
...
the
...
bulk
...
of
...
the
...
sedimentation
...
occurs
...
during
...
loading
...
or
...
is
...
simply
...
residual
...
flocs
...
that
...
have
...
settled
...
there
...
during
...
the
...
settle
...
state
...
and
...
which
...
the
...
flow
...
was
...
unable
...
to
...
clean
...
out.
...
The
...
Lab
...
Floc
...
team
...
will
...
make
...
a
...
few
...
apparatus
...
adjustments
...
to
...
see
...
if
...
we
...
can
...
eliminate
...
the
...
amount
...
of
...
sediment
...
present
...
in
...
the
...
flocculator
...
by
...
redirecting
...
the
...
flow
...
around
...
the
...
setting
...
chamber
...
during
...
the
...
settle
...
state
...
and
...
commence
...
the
...
flushing-out
...
of
...
the
...
flocculator
...
at
...
the
...
same
...
time
...
as
...
settling
...
inside
...
the
...
column
...
occurs.
...
This
...
may
...
elucidate
...
when
...
the
...
majority
...
of
...
the
...
flocs
...
are
...
settling.
...
- Increasing
...
- the
...
- flow
...
- rate
...
- of
...
- our
...
- experimental
...
- apparatus
...
- so
...
- that
...
- we
...
- are
...
- generating
...
- turbulent
...
- flow
...
- inside
...
- the
...
- tube
...
- flocculator.
...
- While
...
- this
...
- option
...
- may
...
- reduce
...
- the
...
- amount
...
- of
...
- flocs
...
- settling
...
- out
...
- of
...
- suspension,
...
- the
...
- increase
...
- in
...
- shear
...
- stress
...
- introduced
...
- by
...
- turbulence
...
- could
...
- disrupt
...
- the
...
- formation
...
- of
...
- flocs.
...
- First,
...
- we
...
- must
...
- determine
...
- if
...
- our
...
- current
...
- apparatus
...
- can
...
- generate
...
- turbulent
...
- pipe
...
- flow.
...
- Additional
...
- pump
...
- heads
...
- and/or
...
- increasing
...
- tubing
...
- size
...
- may
...
- be
...
- required
...
- to
...
- get
...
- the
...
- Reynolds
...
- number
...
- of
...
- the
...
- flow
...
- high
...
- enough
...
- to
...
- transition
...
- into
...
- turbulence.
...
- Once
...
- the
...
- ability
...
- to
...
- generate
...
- turbulent
...
- flow
...
- is
...
- achieved,
...
- we
...
- must
...
- evaluate
...
- whether
...
- we
...
- can
...
- achieve
...
- good
...
- flocculation.
...
- An
...
- additional
...
- challenge
...
- of
...
- operating
...
- in
...
- the
...
- turbulent
...
- regime
...
- is
...
- that
...
- shear,
...
- strain
...
- and
...
- G
...
- are
...
- now
...
- not
...
- so
...
- easily
...
- calculated
...
- and
...
- one
...
- can
...
- no
...
- longer
...
- assume
...
- these
...
- parameters
...
- are
...
- constant
...
- throughout
...
- the
...
- flocculator.
...
- On
...
- the
...
- other
...
- hand,
...
- the
...
- effectiveness
...
- of
...
- laminar
...
- flow
...
- to
...
- generate
...
- flocs
...
- has
...
- also
...
- been
...
- called
...
- into
...
- question.
...
- In
...
- a
...
- perfectly
...
- straight
...
- Poiseuille
...
- flow,
...
- the
...
- parabolic
...
- velocity
...
- profile
...
- requires
...
- that
...
- the
...
- gradient
...
- of
...
- velocity
...
- to
...
- be
...
- zero
...
- at
...
- the
...
- centerline,
...
- which
...
- means
...
- that
...
- if
...
- a
...
- particle
...
- were
...
- to
...
- travel
...
- along
...
- the
...
- centerline,
...
- it
...
- will
...
- have
...
- limited
...
- opportunity
...
- to
...
- collide
...
- with
...
- other
...
- particles
...
- because
...
- there
...
- is
...
- no
...
- gradient
...
- at
...
- the
...
- centerline.
...
- By
...
- having
...
- a
...
- coiled
...
- tube
...
- flocculator,
...
- this
...
- issue
...
- may
...
- have
...
- been
...
- ameliorated
...
- by
...
- the
...
- secondary
...
- flows
...
- generated
...
- by
...
- the
...
- centrifugal
...
- forces
...
- that
...
- disrupt
...
- the
...
- symmetry
...
- of
...
- the
...
- flow.
...
- This
...
- option,
...
- however,
...
- is
...
- the
...
- easiest
...
- option
...
- to
...
- undertake
...
- and
...
- should
...
- be
...
- explored
...
- first.
...
- Minimizing
...
- the
...
- amount
...
- of
...
- horizontally
...
- oriented
...
- tube
...
- sections
...
- should
...
- minimize
...
- settling
...
- because
...
- there
...
- will
...
- be
...
- no
...
- wall
...
- against
...
- which
...
- flocs
...
- could
...
- settle
...
- onto.
...
- This,
...
- however,
...
- would
...
- entail
...
- orienting
...
- the
...
- tube
...
- straight
...
- up
...
- and
...
- down,
...
- which
...
- would
...
- limit
...
- the
...
- length
...
- of
...
- our
...
- flocculator.
...
- If
...
- the
...
- tube
...
- were
...
- wrapped
...
- around
...
- a
...
- long
...
- racetrack-with
...
- the
...
- bends
...
- occurring
...
- at
...
- the
...
- top
...
- and
...
- bottom
...
- of
...
- the
...
- loops
...
- being
...
- much
...
- shorter
...
- than
...
- the
...
- vertical
...
- sides,
...
- we
...
- may
...
- be
...
- able
...
- to
...
- see
...
- some
...
- improvements.
...
- While
...
- this
...
- setup
...
- may
...
- reduce
...
- floc
...
- settling
...
- out
...
- of
...
- the
...
- flow,
...
- it
...
- brings
...
- into
...
- question
...
- whether
...
- laminar
...
- straight
...
- pipe
...
- flow
...
- is
...
- the
...
- right
...
- regime
...
- to
...
- study
...
- flocculation.
...
- As
...
- mentioned
...
- earlier,
...
- there
...
- are
...
- some
...
- theoretical
...
- arguments
...
- against
...
- flocculating
...
- in
...
- Poiseuille
...
- flow.
...
- This
...
- problem
...
- could
...
- be
...
- aided
...
- by
...
- the
...
- addition
...
- of
...
- some
...
- kinks
...
- in
...
- the
...
- pipe
...
- so
...
- that
...
- minor
...
- losses
...
- can
...
- introduce
...
- horizontal
...
- velocity
...
- components
...
- which
...
- will
...
- transport
...
- particles
...
- to
...
- different
...
- radial
...
- locations.
...
- More
...
- calculations
...
- are
...
- needed
...
- to
...
- evaluate
...
- this
...
- option.
...
- A
...
- third
...
- and
...
- most
...
- difficult
...
- option
...
- would
...
- be
...
- to
...
- rotate
...
- the
...
- entire
...
- flocculator
...
- in
...
- such
...
- a
...
- way
...
- that
...
- the
...
- direction
...
- of
...
- gravitational
...
- acceleration
...
- will
...
- always
...
- be
...
- transient
...
- with
...
- respect
...
- to
...
- the
...
- centerline
...
- axis
...
- of
...
- the
...
- tube.
...
- Since
...
- it
...
- is
...
- gravity
...
- that
...
- pulls
...
- floc
...
- out
...
- of
...
- the
...
- flow
...
- and
...
- down
...
- onto
...
- the
...
- wall
...
- oriented
...
- below
...
- the
...
- centerline
...
- of
...
- the
...
- pipe,
...
- by
...
- varying
...
- the
...
- angle
...
- of
...
- the
...
- vector
...
- of
...
- gravitational
...
- acceleration,
...
- sedimentation
...
- might
...
- be
...
- avoided.
...
- This
...
- option
...
- is
...
- the
...
- most
...
- complicated
...
- and
...
- hardest
...
- to
...
- implement
...
- simply
...
- because
...
- it
...
- requires
...
- new
...
- mechanical
...
- equipment
...
- and
...
- non-trivial
...
- design
...
- calculations.
...
Wiki Markup {cloak}
...
| Wiki Markup |
|---|
{toggle-cloak:id=Implementing a new setup} |
...
...
a
...
new setup
| Wiki Markup |
|---|
setup {cloak:id=Implementing a new setup} |
In
...
order
...
to
...
prevent
...
premature
...
sedimentation
...
in
...
the
...
flocculator,
...
we
...
have
...
changed
...
the
...
flocculator
...
setup.
...
The
...
flocculator
...
hollow
...
PVC
...
tube
...
(black)
...
has
...
been
...
replaced
...
with
...
a
...
peg
...
board
...
by
...
which
...
the
...
team
...
can
...
plug
...
in
...
pegs
...
to
...
wrap
...
the
...
flocculator
...
tube
...
around.
...
The
...
board
...
is
...
75
...
inches
...
tall
...
by
...
35
...
inches
...
wide
...
and
...
is
...
supported
...
by
...
a
...
wooden
...
brace
...
to
...
stand
...
vertical.
...
The
...
flocculator
...
tube
...
wraps
...
around
...
10
...
different
...
pegs
...
that
...
form
...
semi-circles
...
on
...
the
...
vertical
...
ends
...
of
...
the
...
board.
...
The
...
50
...
foot
...
flocculator
...
tube
...
wraps
...
around
...
these
...
pegs
...
about
...
three
...
times
...
between
...
rapid
...
mix
...
and
...
the
...
settling
...
column.
...
If
...
the
...
team
...
wanted
...
to
...
shorten
...
the
...
vertical
...
distance
...
that
...
the
...
tube
...
wraps
...
around,
...
it
...
is
...
an
...
easy
...
transition
...
by
...
just
...
replacing
...
the
...
pegs
...
to
...
a
...
different
...
hole
...
on
...
the
...
board.
...
This
...
new
...
setup
...
is
...
convenient
...
and
...
provides
...
a
...
lot
...
of
...
different
...
ways
...
to
...
achieve
...
a
...
vertical
...
flocculator.
...
This
...
new
...
setup
...
reduces
...
the
...
amount
...
of
...
horizontal
...
pieces
...
in
...
the
...
flocculator,
...
and
...
will
...
hopefully
...
reduce
...
or
...
remove
...
the
...
amount
...
of
...
settling
...
altogether.
| Wiki Markup |
|---|
{cloak} h3. |
| Wiki Markup |
|---|
{toggle-cloak:id=Pictures of new setup} |
...
...
of
...
new setup
| Wiki Markup |
|---|
setup {cloak:id=Pictures of new setup} !Laboratory Research Set-Ups^board.jpg|width=200, height=300! !Laboratory Research Set-Ups^board and ET.jpg|width=200, height=300! !Laboratory Research Set-Ups^straight inlet.jpg|width=200, height=300! !Laboratory Research Set-Ups^board-top.jpg|width=250, height=200! From Left to Right: 1) new tube flocculator setup on the board 2) Effluent Turbidimeter 3) The settling column with straight inlet and outlet (straws at the top) 4) Top of the new tube flocculator setup {cloak} h2. |
From Left to Right:
1) new tube flocculator setup on the board
2) Effluent Turbidimeter
3) The settling column with straight inlet and outlet (straws at the top)
4) Top of the new tube flocculator setup
| Wiki Markup |
|---|
{cloak} |
| Wiki Markup |
|---|
{toggle-cloak:id=Data Analysis} |
...
| Wiki Markup |
|---|
Analysis {cloak:id=Data Analysis} |
Data
...
Analysis
...
for
...
the
...
new
...
flocculator
...
setup
...
can
...
be
...
viewed
...
...
.
| Wiki Markup |
|---|
{cloak} |
| Wiki Markup |
|---|
{toggle-cloak:id=Changing the Apparatus Setup for Turbulent Flow} |
...
...
the
...
Apparatus
...
Setup
...
for
...
Turbulent Flow
| Wiki Markup |
|---|
Flow {cloak:id=Changing the Apparatus Setup for Turbulent Flow} |
In
...
order
...
to
...
achieve
...
turbulent
...
flow
...
in
...
our
...
flocculator
...
setup,
...
we
...
needed
...
to
...
figure
...
out
...
if
...
our
...
pumps
...
can
...
handle
...
very
...
high
...
flow
...
rates
...
to
...
get
...
high
...
Reynolds
...
number.
...
For
...
turbulent
...
flow,
...
our
...
target
...
Reynolds
...
number
...
is
...
2500,
...
with
...
flocculator
...
inner
...
diameter
...
of
...
0.6cm.
...
The
...
calculation
...
shows
...
that
...
the
...
flow
...
rate
...
needs
...
to
...
be
...
at
...
least
...
11.8
...
mL/s
...
for
...
turbulent
...
flow.
...
(With
...
our
...
current
...
setup,
...
the
...
max
...
flow
...
rate
...
is
...
3.1
...
mL/s)
...
Thus,
...
one
...
of
...
our
...
solutions
...
was
...
to
...
add
...
more
...
pump
...
heads,
...
since
...
the
...
max
...
flow
...
rate
...
of
...
pump
...
is
...
limited
...
by
...
how
...
fast
...
a
...
pump
...
head
...
motor
...
can
...
rotate.
...
In
...
order
...
to
...
test
...
out
...
how
...
many
...
additional
...
pump
...
heads
...
are
...
needed,
...
we
...
added
...
in
...
new
...
set
...
points
...
to
...
Process
...
Controller
...
method
...
-
...
"3-Alum
...
Number
...
of
...
Heads"
...
and
...
"3-Clay
...
Number
...
of
...
Heads".
...
We
...
found
...
that
...
2
...
alum
...
pump
...
heads,
...
2
...
clay
...
pump
...
heads,
...
and
...
3
...
raw
...
water
...
pump
...
heads
...
are
...
sufficient
...
to
...
provide
...
our
...
target
...
flow
...
rate
...
of
...
11.8
...
mL/s.
| Wiki Markup |
|---|
{cloak} |