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Floc Hopper Design Program

The primary purpose of the floc hopper is to regulate the height of the flocculation blanket found in the sedimentation tanks.

Floc Hopper Design Program Inputs and Outputs

 Floc Hopper Program Inputs

 Floc Hopper Program Outputs

Floc Hopper Design Program Algorithm



 

(We are currently working on placing our drawn Floc Hopper within the plant. Once we complete this goal, we will add pictures of the floc hopper in its place in the plant.) 

The design of the floc hopper depended upon various input parameters concerning the sedimentation tank and lamella, which included the length of the lamella and the width of the sedimentation tank. The floc hopper has a trapezoidal cross-sectional area, and was designed to lie on the sedimentation sludge drain and line up with the sedimentation pipe frame ledge. The floc hopper was designed to rotate from the sedimentation wall chimney so that the floc hopper would line up vertically with the first lamella also extending from the chimney wall. If the angle of the floc hopper (with respect to the sedimentation sludge drain) was greater than 60 degrees, this orientation would allow for maximum efficiency from the floc hopper.
First, the various parameters from the above picture were calculated.
The width of the floc hopper had to line up evenly with the width of the sedimentation sludge drain (this side of the floc hopper lies on the sludge drain):




Unknown macro: {latex}

\large
$$
W_

Unknown macro: {FlocHopper}

= W_

Unknown macro: {SedSludgeFlat}

$$

 
 
The length of the floc hopper is required to cover the entire width of the sedimentation tank, so the two must be equal:

Unknown macro: {latex}

\large
$$
L_

Unknown macro: {FlocHopper}

= W_

Unknown macro: {SedBayActual}

$$

 
  The first lamella and the floc hopper must be lined up vertically - in order for this to happen, the horizontal distance from the bottom of the first lamella to the chimney wall must be equal to the horizontal distance from the top of the floc hopper to the chimney wall.
The horizontal length from the bottom of the first lamella to the chimney wall:

Unknown macro: {latex}

\large
$$
L_

Unknown macro: {FlocHopperOffset}

= L_

Unknown macro: {SedPlate}

\cdot \cos \left( {AN_{SedPlate}} \right)
$$


The vertical component of the floc hopper's height depended on the elevation of the sedimentation inlet slopes, as well as the height of the sedimentation sludge drain. The vertical height:

Unknown macro: {latex}

\large
$$
Z_

Unknown macro: {FlocHopper}

= Z_

Unknown macro: {SedSlopes}

- H_

Unknown macro: {SedSludge}

$$

 
 
 The actual height of the floc hopper was calculated using the Pythagoreas Theorem, with L.FlocHopperOffset and Z.FlocHopper serving as the two sides of a right triangle, and the height of the floc hopper as the hypotenuse:

Unknown macro: {latex}

\large
$$
H_

Unknown macro: {FlocHopper}

= ({L_

Unknown macro: {FlocHopperOffset}

^2 + Z_

2})1 \over 2
$$

 
The thickness of the floc hopper was assumed to be equal to the thickness of the sedimentation slope plate:

Unknown macro: {latex}

\large
$$
T_

Unknown macro: {FlocHopper}

= T_

Unknown macro: {SedSlopePlate}

$$


The angle that the floc hopper must be rotated was then calculated. With respect to the sedimentation sludge drain, the angle the floc hopper must be rotated:

Unknown macro: {latex}

\large
$$
AN_

Unknown macro: {FlocHopper}

= atan\left( {Z_{FlocHopper \over {L_{FlocHopperOffset}}}} \right)
$$

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