How to design a filter?
Based on our filtration flow and velocity of the filter recommended
Recommended velocity of filters
a. PSF,MGF & DMF : 8-10 m/hr (m3/hr/m2) b. Iron removal filter : 6-8 m/hr
c. ACF : 12-18m/hr
d. Softener : upto 25m/hr
e. Rapid filter (recycling application ): upto 50m/hr
Velocity m/hr (m3/hr/m2) : Flow Rate / Cross Section Area(filtration area)
Example: psf capacity – 10m3/hr
Filter area : flow rate/velocity
: 10/8 = 1.25m2 or 10/10= 1 m2
Dia of the filter : 1.1m or = 1m
Filter dia between : 1.1-1m
How to design the water pipe line size?
Based on velocity For pressure line : upto 2.2m/sec
For pump suction : upto 1.8m/sec
If we choose more velocity what will happen
1.Due to friction lose flow will reduce.
2.Due to back pressure pump energy required more
3.Due to back pressure pipe damage may cause
What is Back-flush/Back wash?
The reverse flow of water, through a filter or filtration media, used for removing solids accumulated during the filtration process.
When back wash needed?
Delta pressure reaches (DP) the required value need to refresh the filter
What is delta pressure /Differential Pressure (Dp)?
Defined as the difference in pressure between upstream (inlet side of the filter) and downstream (outlet side of the filter).Normally Dp allowed max 7psi in filter and membrane 5psi each membrane. Even the filter is fresh condition Dp increase the desire value, we have to ensure the water quality and other parameter like pipe line chock.