Pumping against a sand filter

[21121956]

Hello everybody:

For a particular industrial process, it is needed to pump out an effluent with solids in suspension to (against) a gravel and sand filter of around 16 feet height, 5 ft x 5 ft and, inside a pipe, the filtered liquid will flow out of that sand filter by gravity to a trench.

The questions are: how to relate the losses in the sand filter to the losses in the discharge of the pump, as if it was pumping through a discharge pipe? Which is the proper way to calculate the losses in the sand filter?

Your comments are welcome. Thanks.

 

[Artisi]

The sand filter will appear as a head loss against the pump, if a commercial filter the manufacturer should be able to give you the head loss figure for various flow rates - you also need to know the losses as the filter blocks with solids.

If these figures are not available you will need to flow test it to give the head losses before you can finalise you pump selection etc.

 

[sow]

If there is a supplier involved ask them.

If there isnt then Wastewater Engineering by Metcalfe and Eddy gives a methodology for estimating losses through clean and dirty filters. These calcs are quite sensitive to assumptions and data available. I would compare this with data from existing sites and speak to suppliers of the sub layer distribution systems or other types of sand filters.

Regards