CALCULATING PRESSURE DROP THRU AN INLET SCREEN 2

[kaha]

I WOULD APPRECIATE ANY HELP ON CALCULATING THE PRESSURE DROP THROUGH AN INLET SCREEN. THE SCREEN IS AT THE INLET OF A WATER TREATMENT PLANT.

 

[vanstoja]

Chapter 8 in Idelchik (1986), "Handbook of Hydraulic Resistance", Hemisphere Publishing Corp. covers flow through barriers uniformly distributed over channel cross sections. Circular metal wire grids are treated in Diagram 8-6 on page 407. Perforated plates, grids, bars, grills, etc. are also treated.

 

[vanstoja]

The equations for circular metal wire in Idelchik's diagram 8-6 are:
Loss Factor(LF)=delp/(rho*(w1^2/2))=1.3*(1-AR)+((1/AR)-1)^2
for Reynolds Number Re=(w0*d/nu)=>1000 where
d=wire diameter
w1= Velocity in duct upstream of screen
w0= Velocity through the open section of the screen
AR= Aduct/Ascreen(open)
For Re values less than 1000, the Loss Factor is multiplied by a plotted Re-dependent value close to 1.0 from Re=1000 to 300 which rises to about 1.23 at Re=100 and to 1.4 at Re=50.
Idelchik gives different symbols for wire diameter, loss factor and area ratio. I've changed them to simplify the description.