Centrifugal Pumps and Viscosity

When a viscous fluid is handled by a centrifugal pump


[LIST][*]brake horsepower requirement increases[*]the head generated is reduced[*]capacity is reduced[*]efficiency of pump is reduced and the Best Efficiency Point - [I] BEP[/I] - is moved[/LIST]
[img]http://www.egpet.net/vb/images/imported/2011/07/21.png[/img]
The head, flow and capacity at other viscosities than used in the original documentation can be modifying with coefficients.
[h=3]Flow[/h] [INDENT] [I]q[SUB]v[/SUB]= c[SUB]q[/SUB] q (1)[/I]
[I]where [/I]
[I]q[SUB]v[/SUB] = flow compensated for viscosity (m[SUP]3[/SUP]/h, gpm)[/I]
[I]c[SUB]q[/SUB] = viscosity flow coefficient [/I]
[I]q = original flow according pump curve (m[SUP]3[/SUP]/h, gpm)[/I][/INDENT][h=3]Head[/h] [INDENT] [I]h[SUB]v[/SUB]= c[SUB]h[/SUB] h (2)[/I]
[I]where [/I]
[I]h[SUB]v[/SUB] = head compensated for viscosity (m, ft)[/I]
[I]c[SUB]h[/SUB] = viscosity head coefficient [/I]
[I]h = original head according pump curve (m, ft)[/I][/INDENT][h=3]Efficiency[/h] [INDENT] [I]μ[SUB]v[/SUB]= c[SUB]μ[/SUB] μ (3)[/I]
[I]where [/I]
[I]μ[SUB]v[/SUB] = effciency compensated for viscosity [/I]
[I]c[SUB]μ[/SUB] = viscosity efficiency coefficient [/I]
[I]μ = original efficiency according pump curve [/I][/INDENT][h=3]Power - SI units[/h] [INDENT] [I]P[SUB]v[/SUB]= q[SUB]v[/SUB] h[SUB]v[/SUB] ρ[SUB]v[/SUB] g / (3.6 10[SUP]6[/SUP] μ[SUB]v[/SUB]) (4)[/I]
[I]where [/I]
[I]P[SUB]v[/SUB] = power compensated for viscosity (kW) [/I]
[I]ρ[SUB]v[/SUB] = density of viscous fluid (kg/m[SUP]3[/SUP])[/I]
[I]g = acceleration of gravity (9.81 m/s[SUP]2[/SUP]) [/I][/INDENT][h=3]Power - Imperial units[/h] [INDENT] [I]P[SUB]v[/SUB]= q[SUB]v[/SUB] h[SUB]v[/SUB] SG / (3960 μ[SUB]v[/SUB]) (5)[/I]
[I]where [/I]
[I]P[SUB]v[/SUB] = power compensated for viscosity (bhp) [/I]
[I]SG = specific gravity of viscous fluid[/I]
[/INDENT]

The major standard speaking about this point is ANSI/HI 9.6.7 If you have this standard please upload and ISO TR 17766 uploaded here


Greetings

Abo Khaled

thanks so much :)