Expert ForumsMixing

Topic: How do I calculate the agitator power in terms of volume increasing?

anonymous
How do I calculate the agitator power in terms of volume increasing? Diameter of reactor-1.95m Diameter of agitator-1.1m speed-96rpm Volume of rector-6.3 kL Volume of material-3.75 kL Viscosity of material-30000 cp density of material-800 kg/m3 reactor type- GLR Agitor type- 3 blade propeller no baffles What is the power consumption of this volume? I am increasing the volume of material up to 5 kL what is the power consumption in the same reactor, same material?
  • Avatar Dave Dickey Forum Moderator 283 Posts

    Re: How do I calculate the agitator power in terms of volume increasing?

    The power consumption for both volumes is the same, as long as the impeller is fully submerged.  The high viscosity will prevent the formation of a significant vortex, even with no baffles.  The estimated power consumption is 4.9 kW.  The viscosity adjusted power number for these operating conditions is 0.923.
  • Avatar Riaz Malik Community Member 1 Post

    Re: How do I calculate the agitator power in terms of volume increasing?

    Having calculated the agitator power requirements, and following your advice, if the power of agitator is 20 HP, we need to have a motor of 40 HP. Is that correct? Secondly, what if you are using a gear drive - will that be of 40 HP or 20 HP rating? For that, if I am not wrong, the motor has to be of lesser power. I am focusing on power consumption factor too and not over doing anything.
  • Avatar Dave Dickey Forum Moderator 283 Posts

    Re: How do I calculate the agitator power in terms of volume increasing?

    The impeller power required for the Glass-Lined Reactor described in this question is about 5 kW at 3.75 kL.  The recommended motor is 7.5 kW.  The power requirement for this same reactor at 5 kL does not change, about 5 kW.  The volume of fluid in the reactor will have no effect on the amount of power required to rotate the agitator.  The mixing intensity will not be as great at 5 kL as it is at 3.75 kL, but the power to the impeller will not change.

    The answers by this expert are based on the best available interpretation of the information provided.  The consequences of the application of this information are the responsibility of the user.  If clarification is needed, please submit a further question.