Agitation Scaleup Calculation

This web application does the scaleup from smaller to larger scale based on criteria like equal tip speed, power per unit volume, equal Reynold's number, equal shaft speed.

Reactor Geometry

Diameter (T1)

mm

Liquid Level (Z1)

mm

Shaft Speed (N1)

rpm

Agitator Narrow Hydrofoil Wide Hydrofoil Pitched Blade Rushton 6-Blade 180 ° Concave User Defined

D/T Ratio 0.25 0.3 0.4 0.5

Flow Number (Nq)

 

Power Number (Np)

 

Fluid Properties

Density (ρ)

kg/m³

Viscosity (μ )

cP

Scale-up

times

Result

Scale-up Ratio, R = (V2/V1)1/3

Shaft speed scaling is done based on following relation:

N2 = N1 . (1/R)n

The value of n, called the scaling exponent, depends on the physical result to be scaled.

Sacle-up for Equal Reynold's No. Tip Speed Power / Volume Froude No. Shaft Speed

		Units	Base Case	Scale up
Volume	V	m3	400	300
Vessel Diameter	T	mm	400	300
Liquid Level	Z	mm	400	300
Agitator Diameter	D	mm	400	300
Equivalent Diameter	Teq = (4.V/π)1/3	mm	400	300
Scaling Exponent	n			2
Shaft Speed	N	rpm	400	300
Reynold's No.	Re = D2.N.ρ/μ
Tip Speed	π.D.N	m/s
Flow Number	Nq
Pumping Rate	Q = Nq.N.D3	m3/s	400	300
Power Number	Np
Power Drawn	P = Np.ρ.N3.D5	kW	400	300
Power/ Volume	P/V	kW / m3	400	300
Froude Number	Fr = N2.D/g
Bulk Velocity	Vc = 4.Q/(π.Teq2)	m/s	400	300
Scale of Agitation			400	300