# How to find required size of AC gear motor for planetary mixing application? [closed]

I want to find a suitable AC or DC gear motor for concrete paste mixing. The application details are given below

Material type - concrete paste RPM - 30-200rpm Qty of material - 30Liters Mixing style - Planetary To understand the type of mixer, you may consider bakery mixer.

Can somebody help me how to calculate the capacity of gear motor that I have to select for this application?

## 1 Answer

Concrete mixers usually have 3-4 blades attached to the walls of the mixer and rotating with the mixer tilted 60-70 degrees. Let's assume the diameter of the mixer 0.5 meters

Assuming the blades lifting up carry half of the weight of the mix, $$w=30/2 (2.5)\space with 2.5 = density\space of\space mix.$$ w = 37.5 kg. And the work mixer has to do at 100rpm is

$$W = (37.5)9.8.100( 0.5)/60seconds/mins= 306.25 watts$$ This is a very rough approximation. One would need to consider the clumping of the concrete, potentially clutching of the mixer, etc. So for a 200rpm mixer, you'd need a 612-watt motor, say one horsepower.

• Thank you. the concrete mixer I referred here is not tilted one. it is a platform mount mixer. any way tilt angle is not used in your formula. I have to consider a height of the material. in this case, will it be a some other formula considering shear stress and viscosity of the material? Mar 17, 2018 at 9:21
• Why not take what has been offered and adapt it now to match your own assumptions or that which was not clearly stated in your question... Mar 17, 2018 at 16:35