h1. Inlet Channel Design Program
The purpose of thisthe inlet channel program is to determine the dimensions of the inlet channel as well as , the dimensions of thecircular holeports andin the chimneyinlet 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.
h2. The dimensions 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 depth of the channel depend on the water level in the sedtank, which should be about the same as in the channel and the flocculator, and the length of the flocculator, since water runs from the end of the flocculator through the channel.
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 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.
\\
\\
{float:left|border=2px solid black}
[!chimneypic1RenderedInlet.PNGpng|width=500px!|InletSide.bmp]
{float}
\\
\\
\\
\\
{float:left|border=2px solid black}
[!ChimneypicrightInletTop.PNGpng|width=500px!|InletSide.bmp]
{float}
\\
\\
\\
\\
{float:left|border=2px solid black}
[!ChimneypicfrontInletFront.PNGpng|width=500px!|InletSide.bmp]
{float}
\\
\\
h2. Inlet Channel Design Algorithm
[Inlet Channel AutoCAD Drawing|AutoCAD Channel Program]
h3. Algorithm
The primary constraint for designing the channel connecting flocculation and sedimentation tanks is the depth of the channel. The channel must be designed to make sure that the transition between the two tanks does not break up the flocs formed in the flocculation tank.
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 [Fluids 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 squarerootroot of the area of the channel.
{latex}
\large
$$
HW_{InletChannel} = \sqrt {A_{InletChannel} }
$$
{latex}
The heightfirst ofconstraint the inlet channel is equal to for the waterwidth heightof in the inlet channel pluson the plantside freeboardof height,the soweir that thedelivers water isto notthe atchimneys theis veryto top ofconsider the channel.
{latex}
\large
$$
H_{InletChannel} = HW_{InletChannel} + H_{PlantFreeboard}
$$
{latex}
\\
The minimum widthenergy dissipation rate. The area of the inlet channel inand consideration of the energy dissipation rate is equal to the area ofheight of the water in the inletchannel channelhave dividedalready bybeen thecalculated, heightand ofso the waterwidth inmay the inlet channelbe determined:
{latex}
\large
$$
W_{InletChannelED} = {{A_{InletChannel} } \over {HW_{InletChannel} }}
$$
{latex}
Next the size of the channelsports that take the flocculated water down into the inlet chimneys and to the sedimentation slopesports is calculated through the A.Port function in [Fluids Functions|Fluids Functions 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 froomfrom the inlet channel into the inlet chimneys is calculated using an array that loops through the available pipe size diameters and roundrounds the needed diameter up to the next available diameterthroughdiameter through the function found in the [Pipe Database|Pipe Database Design Program].
{latex}
\large
$$
{D_{SedChimneyPipe}} = {D_{pipelarger}}\left( {2\sqrt {{{{A_{SedManifoldEntrance}}} \over \pi }} ,\left. {{D_{Pipesizes}}} \right)} \right.
$$
{latex}
Because theThe 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 determienddetermined by the allowable energy dissipation in the inlet channel, and the width needed by the circular holeport in the inlet chimney.
{latex}
\large
$$
{W_{InletChannelInletChannelEst}} = \max \left( {{W_{InletChannelED}},\left. {{D_{SedChimneyPipe}} + 2{S_{SedInletChannelMin}}} \right)} \right.
$$
{latex}
h4. Stopping flow into the Sedimentation Tank
Sometimes it is necessary to stop water from entering certain inlet chimneys in order to shut off the in-flow to a sedimentation tank. This is useful when it is necessary to clean or make repairs in oneThe 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, orare itshut isoff determinedand thatall notof allthe thewater tanksmust needgo to waste; it must be inable use to producehandle the entire necessaryflow volumerate of cleanthe waterplant.
To Thisdo way, plant operators can isolate certain sed tanks rather than having to turn off the flowthis, 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 entire plant.
The chimney stop plugs have been designed to fit into the inlet chimney couplings in order to stop water from flowing into them. The dimensions of the control piece are derived from the specifications of Inlet Chimneys, using the Pipe Database and new research on PVC pipe caps. 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 [Fluids Functions|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} | 