When a viscous fluid is handled by a centrifugal pump


  • brake horsepower requirement increases
  • the head generated is reduced
  • capacity is reduced
  • efficiency of pump is reduced and the Best Efficiency Point - BEP - is moved


The head, flow and capacity at other viscosities than used in the original documentation can be modifying with coefficients.
[h=Flow]3[/h]
qv= cq q (1)
where
qv = flow compensated for viscosity (m3/h, gpm)
cq = viscosity flow coefficient
q = original flow according pump curve (m3/h, gpm)
[h=Head]3[/h]
hv= ch h (2)
where
hv = head compensated for viscosity (m, ft)
ch = viscosity head coefficient
h = original head according pump curve (m, ft)
[h=Efficiency]3[/h]
μv= cμ μ (3)
where
μv = effciency compensated for viscosity
cμ = viscosity efficiency coefficient
μ = original efficiency according pump curve
[h=Power - SI units]3[/h]
Pv= qv hv ρv g / (3.6 106 μv) (4)
where
Pv = power compensated for viscosity (kW)
ρv = density of viscous fluid (kg/m3)
g = acceleration of gravity (9.81 m/s2)
[h=Power - Imperial units]3[/h]
Pv= qv hv SG / (3960 μv) (5)
where
Pv = power compensated for viscosity (bhp)
SG = specific gravity of viscous fluid