...
Inlet
...
Pipe
...
Calculations:
...
To
...
determine
...
the
...
diameter
...
of
...
the
...
inlet
...
pipe
...
we
...
used
...
the
...
constraint
...
that
...
the
...
maximum
...
shear
...
due
...
to
...
minor
...
losses
...
had
...
to
...
be
...
less
...
than
...
G
...
cell in
...
the
...
last
...
section
...
of
...
the
...
flocculator
...
(G
...
cell =
...
24/s).
...
The
...
predominant
...
minor
...
losses
...
from
...
the
...
inlet
...
pipe
...
will
...
occur
...
at
...
the
...
exit
...
point
...
and
...
the
...
elbow.
...
The
...
minor
...
loss
...
coefficient
...
for
...
the
...
elbow
...
is
...
0.9
...
and
...
the
...
exit
...
is
...
1.0
...
so
...
K
...
was
...
set
...
to
...
be
...
1.0
...
for
...
this
...
design.
...
The
...
equation
...
to
...
calculate
...
shear
...
due
...
to
...
minor
...
losses
...
in
...
a
...
pipe
...
is
...
shown
...
below.
...
This
...
equation
...
is
...
solved
...
for
...
D,
...
the
...
diameter
...
of
...
the
...
pipe
...
that
...
would
...
provide
...
shear
...
equal
...
to
...
G
...
cell.
...
The
...
equation
...
used
...
is
...
very
...
similar
...
to
...
the
...
equation
...
used
...
to
...
find
...
the
...
baffle
...
spacing
...
for
...
the
...
flocculator.
| Include Page | ||||
|---|---|---|---|---|
|
| Wiki Markup |
|---|
{include:Inlet Pipe Diameter} {float:right|border=2px solid black|width=200px} {anchor:inlet}[!Floc_to_Sed.JPG|thumbnail!|width=200px!|Floc_to_Sed.JPG] h5.Inlet Channels From the Floc Tank to the sedimentation tank. {float} |
| Wiki Markup |
|---|
{float:right|border=2px solid black|width=200px}
{anchor:inlet}[!Aerial_Floc_to_Sed.JPG|thumbnail!|width=200px!|Aerial_Floc_to_Sed.JPG]
h5.Inlet Channel From the Floc Tank to the sedimentation tank with lamella (aerial view).
{float}
|
Variables:
...
K
...
=
...
1.0
...
(minor
...
loss
...
for
...
an
...
exit)
...
- This
...
- equation
...
- was
...
- derived
...
- from
...
- a
...
- series
...
- of
...
- substitutions
...
- that
...
- can
...
- be
...
- seen
...
- above.
...
- The
...
- head
...
- loss
...
- term
...
- that
...
- is
...
- found
...
- in
...
- the
...
- above
...
- derivation
...
- is
...
- assumed
...
- to
...
- include
...
- only
...
- minor
...
- losses.
...
- The
...
- minor
...
- head
...
- loss
...
- for
...
- this
...
- pipe
...
- is
...
- assumed
...
- to
...
- be
...
- the
...
- dominating
...
- factor
...
- because
...
- the
...
- pipe
...
- is
...
- designed
...
- to
...
- be
...
- relatively
...
- short
...
- in
...
- length
...
- and
...
- the
...
- bends
...
- and
...
- exit
...
- are
...
- our
...
- major
...
- sources
...
- of
...
- shear,
...
- the
...
- primary
...
- locations
...
- where
...
- floc
...
- break
...
- up
...
- would
...
- occur.
...
- The
...
- velocity
...
- equals
...
- Q/A
...
- for
...
- the
...
- pipe.
...
- The
...
- residence
...
- time
...
- term
...
- is
...
- found
...
- to
...
- be
...
- the
...
- volume
...
- over
...
- the
...
- flow
...
- rate
...
- through
...
- that
...
- volume.
...
- The
...
- volume
...
- used
...
- was
...
- assumed
...
- to
...
- be
...
- the
...
- cross
...
- sectional
...
- area
...
- of
...
- the
...
- pipe
...
- times
...
- 2
...
- diameters
...
- of
...
- the
...
- pipe.
...
Note:
...
Initially
...
during
...
preliminary
...
design
...
with
...
a
...
large
...
tank,
...
we
...
were
...
using
...
55
...
L/min
...
as
...
the
...
plant
...
flow
...
rate,
...
and
...
the
...
required
...
pipe
...
diameter
...
was
...
5.11
...
to
...
achieve
...
the
...
desired
...
G
...
cell value.
...
Due
...
to
...
the
...
cost
...
of
...
15.24cm
...
(6")
...
bulkhead
...
fittings
...
(nearly
...
$300),
...
we
...
had
...
to
...
find
...
an
...
alternative
...
design.
...
We
...
decided
...
to
...
lower
...
the
...
flow
...
until
...
a
...
pipe
...
with
...
inlet
...
diameter
...
equal
...
to
...
10.16cm
...
(4")
...
was
...
achieved.
...
We
...
found
...
that
...
the
...
maximum
...
flow
...
for
...
these
...
conditions
...
is
...
24
...
L/min,
...
so
...
we
...
changed
...
the
...
flow
...
rate
...
of
...
the
...
sedimentation
...
tank.
...
The
...
option
...
of
...
multiple
...
inlets
...
was
...
considered
...
but
...
this
...
was
...
discarded
...
because
...
then
...
2
...
-
...
4
...
bulk
...
head
...
fittings
...
would
...
be
...
needed.
...
Thus,
...
the
...
overall
...
flow
...
of
...
the
...
tank
...
was
...
lowered
...
and
...
a
...
smaller
...
tank
...
was
...
chosen.
...