Continuing the design of preliminary treatment facilities for the village of Fishkill WW...

Continuing the design of preliminary treatment facilities for the village of Fishkill WWTP ( Problem 13-2 ), design an aerated grit chamber. Use Albrecht’s equation and assume the required bottom velocity must achieve removal of a 60 μ m SES particle. Assume the sewers are separated and use a worst case situation for the design of the grit channel. To complete the design, specify the air supply rate and provide a sketch of the cross section with dimensions.

Problem 13-2

Using the pumps given in Table 13-1, design a screw pump system for the village of Fishkill using the following assumptions:

Interceptor sewer

Minimum sewage elevation = 112.60 m

Maximum sewage elevation = 112.80 m

Discharge elevation to stilling well = 116.40 m

Average flow at design life = 8,600 m³/d

Peaking factor for peak hour = 2.8

Ratio factor for minimum flow at beginning of design life = 0.49

Complete the design by providing the following: pump specifications (diameter, number of flights), number of pumps, and a sketch of the plan view with dimensions (assume the width of each pump equals the diameter of the screw plus 0.6 m).

Table 13-1