Power Number definition

For improved performance it’s good to be aware of Np

For a specific vessel with specific internals (like baffles, deep tubes, sensors) the Power Number of the specific rotor at a specified rotational speed, in a liquid with known density, can be calculated with knowledge about the consumed rotor power measured in Watt.

Watt = Power Number x Density x Agitator speed³ x Rotor Diameter⁵

Rotor power consumption (in Watt) is though difficult to measure. Scientific articles don’t suggest an easy way to measure the precise Watt consumption. The article below measure the torque at the rotor shaft with a specific engineered setup. An accurate and simple method is to use Perseus or Cilix to measure exactly rotor Watt and get accurate Power Number in real-time.

IMP P 080 03 30 R 01

IMP M 075 03 30 L 01

IMP K 040 03 45 L 01

CerCell offer from stock 650 different impellers each with a name code: principal type, diameter in mm, number of blades, blade angle in degree, direction (Left or Right).

Typical values of small impeller Power Number (N_p) range between 1-3.

TUR B 070 6 L 02

TUR R 070 6 01

TUR B 040 6 R 02

CerCell offer from stock 150 different turbines with a specific name code: principal type, diameter in mm, number of blades, blade angle in degree, direction (Left or Right).