Backwash Filter Calculations

Dear Goyal,

The value for velocity can be derived from the following formula:

Flow = pi* R²* Velocity

R = Radius of the Filter vessel

Or Velocity = Flow/pi*R²

As for the number of holes in the laterals can be calculated once the Diameter of the filter is known.

I forgot to enter my details,

I am Naseem Aziz, From Karachi Pakistan,

email: pakways@gmail.com

What is the material being backwashed?

What is the medium used before the filter to remove solids?

What is the max flow rate of the filter?

More and larger holes provide a faster the flow.

You can even cut the holes at an angle to allow for faster flow.

Dear Colleague,

In your specific application you determine the diameter of the holes in the filter laterals depending on the filter media that you are going to use.

Once that has been determined make a simple calculation D (internal diameter of your discharge pipe or pipes)/ d(diameter of holes in the filter laterals).

The answer will give you the number of holes you require in the laterals.You can allow for more holes to allow for the frictional & turbulence losses in the pipe.

This is just a suggestion.