...
Inlet
...
Channel
...
Design
...
Program
...
The
...
purpose
...
of
...
the
...
inlet
...
channel
...
program
...
is
...
to
...
determine
...
the
...
dimensions
...
of
...
the
...
inlet
...
channel,
...
the
...
dimensions
...
of
...
circular
...
ports
...
in
...
the
...
inlet
...
chimneys
...
that
...
deliver
...
water
...
from
...
the
...
inlet
...
channel
...
into
...
the
...
sedimentation
...
tank,
...
and
...
the
...
dimensions
...
of
...
the
...
weir
...
in
...
the
...
inlet
...
channel
...
that
...
will
...
regulate
...
the
...
height
...
of
...
the
...
water
...
in
...
the
...
inlet
...
channel
...
and
...
flocculator.
...
The
...
inlet
...
channel
...
will
...
run
...
along
...
the
...
inlet
...
end
...
of
...
the
...
sedimentation
...
tanks,
...
such
...
that
...
its
...
length
...
will
...
be
...
equal
...
to
...
the
...
combined
...
widths
...
of
...
all
...
the
...
sedimentation
...
tanks
...
plus
...
the
...
thickness
...
of
...
the
...
walls
...
between
...
the
...
tanks
...
and
...
the
...
thickness
...
of
...
the
...
walls
...
that
...
separate
...
the
...
bays
...
within
...
the
...
sedimentation
...
tank
...
channels.
...
The
...
Inlet
...
Channel
...
Weir
...
The
...
purpose
...
if
...
the
...
inlet
...
weir
...
is
...
to
...
regulate
...
the
...
height
...
of
...
water
...
in
...
the
...
inlet
...
channel
...
and
...
flocculator.
...
This
...
is
...
accomplished
...
by
...
a
...
relation
...
between
...
the
...
width
...
of
...
the
...
weir
...
and
...
the
...
head
...
loss
...
over
...
the
...
weir,
...
which
...
is
...
governed
...
by
...
the
...
equation:
| Latex |
|---|
} \large $$ W = {3 \over 2}{Q \over {K_{VC} \sqrt {2g} H^{{3 \over 2}} }} $$ {latex} |
Where
...
W
...
is
...
the
...
width
...
of
...
the
...
weir
...
and
...
H
...
is
...
the
...
head
...
loss
...
over
...
the
...
weir.
...
The
...
weir
...
can
...
either
...
be
...
placed
...
parallel
...
or
...
perpendicular
...
to
...
the
...
length
...
of
...
the
...
channel.
...
Parallel
...
Weir
...
The
...
parallel
...
weir
...
will
...
be
...
placed
...
in
...
the
...
inlet
...
channel
...
such
...
that
...
it
...
will
...
satisfy
...
two
...
constraints.
...
First
...
that
...
on
...
the
...
side
...
of
...
the
...
weir
...
that
...
delivers
...
water
...
to
...
the
...
inlet
...
chimneys,
...
the
...
width
...
of
...
the
...
channel
...
will
...
be
...
wide
...
enough
...
so
...
that
...
the
...
energy
...
dissipation
...
rate
...
associated
...
with
...
the
...
channel
...
geometry
...
will
...
be
...
greater
...
than
...
the
...
energy
...
dissipation
...
rate
...
at
...
the
...
end
...
of
...
the
...
flocculator
...
and
...
will
...
also
...
be
...
wide
...
enough
...
to
...
fit
...
the
...
ports
...
leading
...
to
...
the
...
inlet
...
chimneys
...
plus
...
an
...
additional
...
3
...
cm
...
of
...
space
...
on
...
each
...
side
...
of
...
the
...
port.
...
The
...
second
...
constraint
...
for
...
placing
...
the
...
weir
...
will
...
be
...
that
...
on
...
the
...
side
...
of
...
the
...
weir
...
that
...
delivers
...
water
...
to
...
waste,
...
the
...
channel
...
will
...
be
...
wide
...
enough
...
to
...
handle
...
the
...
flow
...
of
...
water
...
in
...
the
...
event
...
that
...
all
...
sedimentation
...
tanks
...
are
...
shut
...
off
...
and
...
all
...
of
...
the
...
water
...
coming
...
from
...
the
...
flocculator
...
must
...
go
...
to
...
waste;
...
it
...
must
...
be
...
able
...
to
...
handle
...
the
...
entire
...
flow
...
of
...
the
...
plant.
...
Perpendicular
...
Weir
...
The
...
perpendicular
...
weir
...
design
...
is
...
placed
...
inside
...
the
...
inlet
...
channel
...
such
...
that
...
the
...
energy
...
dissipation
...
rate
...
associated
...
with
...
the
...
inlet
...
chimneys
...
will
...
be
...
much
...
greater
...
than
...
the
...
energy
...
dissipation
...
rate
...
in
...
the
...
open
...
inlet
...
channel.
...
A
...
perpendicular
...
weir
...
also
...
must
...
be
...
placed
...
so
...
that
...
it
...
can
...
handle
...
the
...
entire
...
flow
...
of
...
the
...
plant
...
if
...
all
...
the
...
sedimentation
...
tanks
...
are
...
turned
...
off
...
and
...
all
...
water
...
is
...
going
...
to
...
waste.
| Wiki Markup |
|---|
\\ \\ {float:left|border=2px solid black} [!RenderedInlet.png|width=500px!|InletSide.bmp] {float} \\ \\ \\ \\ |
| Wiki Markup |
|---|
{float:left|border=2px solid black}
[!InletTop.png|width=500px!|InletSide.bmp]
{float}
\\ |
| Wiki Markup |
|---|
\\ \\ \\ {float:left|border=2px solid black} [!InletFront.png|width=500px!|InletSide.bmp] {float} \\ \\ h2. |
Inlet Channel Design Algorithm
Algorithm
The length of the channel is a function of the number of sedimentation tanks, and the thickness of the walls between the sedimentation tanks.
| Latex |
|---|
Inlet Channel Design Algorithm [Inlet Channel AutoCAD Drawing|AutoCAD Channel Program] h3. Algorithm The length of the channel is a function of the number of sedimentation tanks, and the thickness of the walls between the sedimentation tanks. {latex} \large $$ L_{Channel} = (N_{SedTanks} )(W_{Sed} ) + (N_{SedTanks} + 1)(T_{PlantWall} ) $$ {latex} |
The
...
cross
...
sectional
...
area
...
of
...
the
...
inlet
...
channel
...
on
...
the
...
side
...
of
...
the
...
weir
...
that
...
delivers
...
water
...
to
...
the
...
inlet
...
chimneys
...
is
...
determined
...
using
...
the
...
A.Port
...
function
...
in
...
| Latex |
|---|
Functions|Fluids Functions Design Program] {latex} \large $$ A_{InletChannel} = A_{Port} (Pi_{FlocDissipation} ,K_{LTurn90} ,Q_{Plant} ,ED_{SedInlet} ,Pi_{VenaContractaOrifice} ) $$ {latex} |
Therefore
...
the
...
height
...
of
...
the
...
water
...
in
...
the
...
inlet
...
channel
...
is
...
equal
...
to
...
the
...
square
...
root
...
of
...
the
...
area
...
of
...
the
...
channel.
| Latex |
|---|
} \large $$ HW_{InletChannel} = \sqrt {A_{InletChannel} } $$ {latex} |
The
...
first
...
constraint
...
for
...
the
...
width
...
of
...
the
...
inlet
...
channel
...
on
...
the
...
side
...
of
...
the
...
weir
...
that
...
delivers
...
water
...
to
...
the
...
chimneys
...
is
...
to
...
consider
...
the
...
energy
...
dissipation
...
rate.
...
The
...
area
...
of
...
the
...
inlet
...
channel
...
and
...
the
...
height
...
of
...
the
...
water
...
in
...
the
...
channel
...
have
...
already
...
been
...
calculated,
...
and
...
so
...
the
...
width
...
may
...
be
...
determined:
| Latex |
|---|
} \large $$ W_{InletChannelED} = {{A_{InletChannel} } \over {HW_{InletChannel} }} $$ {latex} |
Next
...
the
...
size
...
of
...
the
...
ports
...
that
...
take
...
the
...
flocculated
...
water
...
down
...
into
...
the
...
inlet
...
chimneys
...
and
...
to
...
the
...
sedimentation
...
ports
...
is
...
calculated
...
through
...
the
...
A.Port
...
function
...
in
...
...
| Latex |
|---|
Design Program]. {latex} \large $$ A_{SedManifoldEntrance} = A_{Port} (Pi_{FlocDissipation} ,K_{PipeEnt} ,Q_{SedManifold} ,ED_{SedInlet} ,Pi_{VenaContractaOrifice} ) $$ {latex} |
The
...
diameter
...
of
...
the
...
hole
...
that
...
delivers
...
the
...
water
...
from
...
the
...
inlet
...
channel
...
into
...
the
...
inlet
...
chimneys
...
is
...
calculated
...
using
...
an
...
array
...
that
...
loops
...
through
...
the
...
available
...
pipe
...
size
...
diameters
...
and
...
rounds
...
the
...
needed
...
diameter
...
up
...
to
...
the
...
next
...
available
...
diameter
...
through
...
the
...
function
...
found
...
in
...
the
...
...
| Latex |
|---|
|Pipe Database Design Program]. {latex} \large $$ {D_{SedChimneyPipe}} = {D_{pipelarger}}\left( {2\sqrt {{{{A_{SedManifoldEntrance}}} \over \pi }} ,\left. {{D_{Pipesizes}}} \right)} \right. $$ {latex} |
The
...
circular
...
hole
...
through
...
the
...
inlet
...
chimneys
...
must
...
have
...
at
...
least
...
3
...
cm
...
of
...
space
...
around
...
it,
...
and
...
so
...
the
...
second
...
constraint
...
on
...
the
...
width
...
of
...
the
...
inlet
...
channel
...
on
...
the
...
side
...
of
...
the
...
weir
...
that
...
delivers
...
the
...
water
...
to
...
the
...
chimneys
...
is
...
that
...
it
...
must
...
be
...
at
...
least
...
as
...
wide
...
as
...
the
...
diameter
...
of
...
this
...
port,
...
plus
...
the
...
3
...
cm
...
of
...
space
...
needed
...
on
...
each
...
side
...
of
...
the
...
port.
...
Therefore
...
the
...
width
...
of
...
the
...
inlet
...
channel
...
on
...
the
...
side
...
of
...
the
...
weir
...
delivering
...
water
...
to
...
the
...
chimneys
...
is
...
set
...
to
...
be
...
the
...
maximum
...
of
...
the
...
width
...
determined
...
by
...
the
...
allowable
...
energy
...
dissipation
...
in
...
the
...
inlet
...
channel,
...
and
...
the
...
width
...
needed
...
by
...
the
...
circular
...
port
...
in
...
the
...
inlet
...
chimney.
| Latex |
|---|
} \large $$ {W_{InletChannelEst}} = \max \left( {{W_{InletChannelED}},\left. {{D_{SedChimneyPipe}} + 2{S_{SedInletChannelMin}}} \right)} \right. $$ {latex} |
The
...
height
...
of
...
the
...
inlet
...
channel
...
is
...
equal
...
to
...
the
...
water
...
height
...
in
...
the
...
inlet
...
channel
...
plus
...
the
...
plant
...
freeboard
...
height,
...
so
...
that
...
the
...
water
...
is
...
not
...
at
...
the
...
very
...
top
...
of
...
the
...
channel.
| Latex |
|---|
} \large $$ H_{InletChannel} = HW_{InletChannel} + H_{PlantFreeboard} $$ {latex} |
As
...
mentioned
...
earlier,
...
the
...
inlet
...
channel
...
weir
...
will
...
serve
...
to
...
regulate
...
the
...
height
...
of
...
the
...
water
...
in
...
the
...
inlet
...
channel.
...
On
...
one
...
side
...
of
...
the
...
weir,
...
the
...
water
...
is
...
being
...
delivered
...
to
...
the
...
inlet
...
chimneys.
...
On
...
the
...
other
...
side
...
of
...
the
...
weir,
...
water
...
will
...
go
...
to
...
waste
...
when
...
the
...
sedimentation
...
tanks
...
are
...
shut
...
off.
...
The
...
width
...
of
...
this
...
side
...
of
...
the
...
weir
...
is
...
determined
...
to
...
be
...
able
...
to
...
handle
...
the
...
flow
...
in
...
the
...
case
...
that
...
all
...
of
...
the
...
sedimentation
...
tanks
...
are
...
shut
...
off
...
and
...
all
...
of
...
the
...
water
...
must
...
go
...
to
...
waste;
...
it
...
must
...
be
...
able
...
to
...
handle
...
the
...
entire
...
flow
...
rate
...
of
...
the
...
plant.
...
To
...
do
...
this,
...
the
...
inlet
...
channel
...
must
...
have
...
a
...
width
...
that
...
will
...
yield
...
a
...
desired
...
head
...
loss.
...
Taking
...
advantage
...
of
...
the
...
fact
...
that
...
head
...
loss
...
is
...
proportional
...
to
...
the
...
width
...
of
...
the
...
channel,
...
the
...
width
...
of
...
the
...
inlet
...
channel
...
on
...
the
...
side
...
of
...
the
...
weir
...
that
...
delivers
...
water
...
to
...
waste
...
is
...
determined
...
through
...
an
...
iterative
...
solution
...
that
...
compares
...
the
...
channels
...
width
...
and
...
calculated
...
head
...
loss
...
to
...
a
...
target
...
head
...
loss
...
and
...
then
...
adjusts
...
the
...
width
...
until
...
the
...
target
...
head
...
loss
...
is
...
reached.
...
This
...
algorithm
...
can
...
be
...
found
...
in
...
...
| Latex |
|---|
|Fluids Functions Design Program]. {latex} \large $$ W_{InletChannelWaste} = w_{channel\min HL} (H_{SedWeirInlet} ,H_{SedWeirInlet} ,Q_{Plant} ,L_{Channel} ,Nu_{Water} ,E_{Concrete} ,1,HL_{SedWeir} ) $$ {latex} |
The
...
width
...
of
...
the
...
entire
...
inlet
...
channel
...
is
...
now
...
the
...
sum
...
of
...
the
...
width
...
of
...
the
...
channel
...
delivering
...
water
...
to
...
the
...
inlet
...
chimneys,
...
the
...
thickness
...
of
...
the
...
weir,
...
and
...
the
...
width
...
of
...
the
...
channel
...
delivering
...
water
...
to
...
waste:
| Latex |
|---|
} \large $$ W_{InletChannel} = W_{InletChannelEst} + T_{SedWeir} + W_{InletChannelWaste} $$ {latex} h3. Stopping the Flow of Water into the Sedimentation Tank The inlet chimneys carry water from the inlet channel into the bottom of the sedimentation tank. However, sometimes it is necessary to shut off the flow of water into a sedimentation tank in order to clean it, make repairs, or to close it off if the plant is producing an excess of clean water. For this purpose, control pieces are needed to stop the flow of water into the chimneys. Individual control pieces for each chimney are advantageous because a particular sedimentation tank can be shut off while still allowing the rest of the plant to function normally. The control piece consists of three parts: 1. A PVC pipe to fit into the coupling of the inlet chimney 2. A cap to cover the top of the PVC pipe 3. A thin, long tube that comes out of the cap and extends above the height of the water in the inlet channel to allow air to escape !chimneystop.png|width=562,height=391! The constraint for designing this control piece is the diameter of the coupling in the inlet chimney, which is derived from the variable D.SedChimneyPipe, the diameter of the chimney itself. With this variable, and using the information in the pipe database that specifies PVC coupling and cap sizes for a particular PVC pipe size, the dimensions of the rest of parts (1) and (2) of the control piece are determined. The specifications for the long tube are that it is less than 1 inch in diameter and that its height extends above the height of the water in the inlet channel (HW.InletChannel), so that air can flow out of it, and it is easy to pull out. !chimneystopandcoupling.png|width=356,height=608! These chimney plugs are one half of the control pieces being designed to allow for the shutting off and re-filling of a sedimentation |
Stopping the Flow of Water into the Sedimentation Tank
The inlet chimneys carry water from the inlet channel into the bottom of the sedimentation tank. However, sometimes it is necessary to shut off the flow of water into a sedimentation tank in order to clean it, make repairs, or to close it off if the plant is producing an excess of clean water. For this purpose, control pieces are needed to stop the flow of water into the chimneys. Individual control pieces for each chimney are advantageous because a particular sedimentation tank can be shut off while still allowing the rest of the plant to function normally.
The control piece consists of three parts:
1. A PVC pipe to fit into the coupling of the inlet chimney
2. A cap to cover the top of the PVC pipe
3. A thin, long tube that comes out of the cap and extends above the height of the water in the inlet channel to allow air to escape
The constraint for designing this control piece is the diameter of the coupling in the inlet chimney, which is derived from the variable D.SedChimneyPipe, the diameter of the chimney itself. With this variable, and using the information in the pipe database that specifies PVC coupling and cap sizes for a particular PVC pipe size, the dimensions of the rest of parts (1) and (2) of the control piece are determined. The specifications for the long tube are that it is less than 1 inch in diameter and that its height extends above the height of the water in the inlet channel (HW.InletChannel), so that air can flow out of it, and it is easy to pull out.
These chimney plugs are one half of the control pieces being designed to allow for the shutting off and re-filling of a sedimentation tank.