Design of Agitator ###8 Batch Volume V = 4 ###6 Vessel Diameter T = 1.5 ###6 Agitator diameter D = 0.6 ###

Agitation rpm N = 100 rpm ###

l = 3 m ###

No of Agitator n = 2 ######

Properties of reactor contents ###Density ℓ = 1200 kg/m3 ###Viscosity µ = 100 cp ###

###Agitator Data

7 Agitator Type

Calculation

Power Requirement

Power Number Np = 4.8Power Required P = 5.637 hpGland Loss (10%) = 0.564 hpTransmission loss (20%) = 1.240Total requirement P = 7.44 hpRounding to P = 7.00 hp

Agitator shaft diameterSelect shaft MOC = SS304

Permissible shear stress, fs = 40 N/mm2Elastic limit , f = 260 N/mm2Modulus of Elasticity, E = 210000 N/mm2

Output Torque, Tc = 498917.2 N-mmMax. torque, Tm = 748375.8 N-mmPolar modulus of section of c/s , Zp = 18709.395

= 95334.496d = 45.68 mm

= 3326 NBending moment, M = 9978344 N-mm

Overhang of agitator between shaft bearing & agitator

mm3

(d)3 mm3

Force acting on radius from the axis of agitator shaft, Fm

Equivalent bending moment, Me = 9992356 N-mmElastic limit, f = 1068

Elastic limit is greater than permissible limit,Change agitator diameter, d

d = 95 mmElastic limit, f = 119

Elastic limit is within permissible limit

Deflection of Shaft (D):I = 3996171 mm4D = 36 mm

Critical Speed (Nc):

Nc = 158 rpm

Actual speed as % of critical speed = 63.1 %

Design is Satisfactory

Checked with critical speed.

70 to 130 % of the critical speed.

N/mm2

N/mm2

Note: Actual speed of agitator should be 40 to 65 % of the critical speed and should not be

Enter agitator dia in 'mm'