Question

A rapid sand filter has a loading rate of 8.00 m/h, surface dimensions of , an effective filtration rate of 7.70 m/h, and a production efficiency of 96 percent. A complete filter cycle duration is 52 h and the filter is rinsed for 20 minutes at the start of each cycle

Required:
a. What flow rate (m3/s) does the filter handle during production?
b. What volume of water is needed for backwashing plus rinsing the filter in each filter cycle?

Answer 1

Answer: hello there is a Missing information below is the missing information

surface dimensions of  10m * 8m

answer :

a) 640 m^3/hr

b) 1334.66 m^3

Explanation:

a) Determine the flow rate ( m^3/s ) of the filter handle

Va = Q /A$_{f}$

where ; Va = filtration rate ( 8.00 m/h ) ,  Q = flow rate of filter handle , A$_{f}$ = surface area ( 10 m * 8 m  )

Q = 8 * ( 10m * 8m ) = 640 m^3 / hr

b) Determine the volume of water needed for backwashing plus rinsing the filter in each filter cycle

Лf = 0.96  ( production efficiency )

Vb + Vr = 0.04 Vf

∴ Vf  =  ( Vb + Vr ) / 0.04  ------ ( 1 )

next step ; determine the volume of filtered water making use of effective filtration rate

Ref = ( Vf - Vb - Vr ) / A$_{f}$T$_{c}$

therefore : Vb + Vr = Vf - ( 80 * 52 * 7.7 ) ----  ( 2 )

Input equation 1 into 2

Vb + Vr = ( ( Vb + Vr ) / 0.04  )  - 32032  ---- ( 3 )

Resolve equation 3

hence the Volume of water needed for Backwashing  and rinsing the filter in each filter cycle

= 1334.66 m^3