hello there,

i am currently doing an assignment on pneumatically conveying cement.

what would a typical solids friction factor be for such a system?

basic details of a test rig gave:

Ms = 2.12 kg/s

Ma = 0.081 kg/s

delta P = 315 kPa

length = 176m

dia = 53mm

the system is dense phase.

i have calculated an average velocity of 12m/s.

i have also calculated an average air density of just over 3kg/m^3. to me this seems incredibly high.

the number i have calculated for the solids friction fator comes out at -63000 ! this tells me that i have made a crucial error in my spreadsheet.

any ideas on what is looking to be out of order?

much appreciated. ■