Calculation of power absorbed at agitator shaft

• abhimanyu09

abhimanyu09

I have with me an existing Agitator details of which are as below

Motor= 2.2KW/ 3 HP, 1440 Rpm
Gear Reducer = ratio 40/1
Agitator Shaft RPM= 36
Agitator Shaft dimension
Length = 2500mm round bar , SS 304
Blades = 5 nos, 100 mm wide, 5 mm thick, dia = 2200 mm, at a distance of 400mm each, ss 304
weight of the agitator shaft & impeller assembly = approx 177 lbs
Purpose of agitation : Alum tank agitator
density ~ 1.3 - 1.4

Now i need the one more exact assembly to increase the capacity of my Plant, however i have no clue how to derive the absorbed power at the agitator shaft or the torque requirement to drive the agitator shaft. I have basic knowledge of gear reducer selection for which i need to calculate the absorbed power.

Can someone please suggest how to do that.
Also is it possible to directly select the Gear reducer based on the motor input KW ? If so then how ?

Thanks in advance.

Answers and Replies

To calculate the absorbed power at the agitator shaft, you will need to know the viscosity of the liquid being agitated, and the amount of agitation needed for your application. The viscosity will affect the torque required to turn the agitator shaft, and the amount of agitation will affect the speed of the shaft. You can then use the following formula to calculate the absorbed power:Power (P) = Torque (T) x RPM (n) Once you have calculated the absorbed power, you can use this to select the appropriate gear reducer for your application. Generally speaking, it is best to select a gear reducer with a power rating that is higher than the calculated absorbed power, to ensure that the gear reducer can handle the load. It is also possible to directly select a gear reducer based on the motor input KW, however, this should be done with caution as the gear reducer will need to be able to handle the specific torque requirements of your application. It is generally recommended to select a gear reducer with a power rating that is higher than the calculated absorbed power, as mentioned above.