How do you calculate the power of an impeller?
Power = Np * n3 * d5 * sg * K The value of the dimensionless power number (Np) depends on several factors including impeller design, number of impellers and location within a tank, tank baffling and fluid viscosity. Typically the power number is shown for mixing in fully turbulent flow.
What is the impeller power number?
Typical spacing between impellers is one impeller diameter….Power and Power Number.
| Impeller | Power Number, NP | Ref |
|---|---|---|
| Propeller, T/D = 3; C/D = 0.75 to 1.3; 4 standard baffles; H/D = 2.7 to 3.9; 3 blades; pitch = D | 0.35 | 12 |
| Marine propeller; T/D = 3; T/C = 3; D/W = 5; 1.0 pitch; 4 standard baffles | 0.34 | 9 |
What does power number mean in mixing?
The power number Np (also known as Newton number) is a commonly used dimensionless number relating the resistance force to the inertia force. The power-number has different specifications according to the field of application. E.g., for stirrers the power number is defined as: with. P: power.
What is axial mixing?
8.3. Axial flow is necessary for top-to-bottom mixing in stirred tanks. Axial flow is generated by impellers with inclined or pitched blades that make an angle of less than 90° with the plane of rotation. Axial flow is particularly useful when strong vertical currents are required.
What is power number formula?
ρ = Fluid Density. n = Rotational Speed. D Diameter of Stirrer. Power number relates resistance force to the inertia force. Newton number formula is derived based on the power, fluid density, rotational speed, and diameter of stirrer.
What is my power number?
To calculate your Power Number, first use your birth date to find your Birth Path Number: Example: August 4, 1961 = 8+4+1+9+6+1 = 29. Break that down to 2+9 = 11. Further break that down to 1+1 = 2.
How do you calculate reactor agitator power requirement?
Agitator speed is then determined using relation Nq = Q/ND3, where N is the Agitator speed. Reynolds number is calculated using relation, Re = D2Nρ/μ and a new Pumping number is determined using generic agitator curves….Agitator Power.
| Batch Volume | Π .Teq3/4 | |
|---|---|---|
| Q | m³/s | 0.450 |
What is axial mixing and radial mixing?
Turbulent mixers can be further categorized as axial or radial flow mixers. Axial flow impellers cause the tank fluid to flow parallel to the impeller’s axis of rotation while radial flow impellers cause the tank fluid to flow perpendicular to the impeller’s axis of rotation.
What is lateral mixing?
Any lateral mixing (mixing at right angles to the flow direction) occurs by the action of diffusion between layers of the liquid. Diffusion mixing can be slow however if the diameter of the pipe of tube is small then this diffusive mixing can be very significant.
What is power number Reynolds number?
It can be seen from this equation that if the power number for a given system is known, the power consumption, P, can be predicted from the fluid density, ρ, impeller diameter, D, and rotational speed, N. The Reynolds number is the ratio of inertial forces to viscous forces (McCabe et. al., 2005).
What is the power of number 9?
It represents patience and harmony. It is the number of love and faith. The qualities of digit 9 include friendship, spirituality, unity, ability to see things clearly and much more. It is the most sophisticated of all numbers.
What are the different types of axial flow impellers?
Some of our most popular axial flow impellers include: High solidity (HS) hydrofoil impellers: HS axial flow impellers are designed for use with high- and medium-viscosity blending, solids suspension, gas dispersion and high head pumping. They feature wide-angled blades that produce strong axial flow patterns and superior gas handling.
What are the different types of industrial mixer impellers?
A primary classification of industrial mixer impellers is their liquid flow pattern in a mixed vessel. This characteristic is used to provide the type of mixing that is desired for a particular application. Axial flow impellers are designed to provide primarily an up and down flow pattern.
What is power number of impeller?
Power number is a value specific to mixing impellers which describes the impeller’s power consumption. The formula for calculating an impeller’s power number is where: NP= power number P = impeller power in watts ρ = density of tank liquid in kg/m3 n = shaft speed in revolutions/second
What is the relationship between dimensionless power number and impeller design?
The relationship of these components can be expressed in the following equation: The value of the dimensionless power number (Np) depends on several factors including impeller design, number of impellers and location within a tank, tank baffling and fluid viscosity. Typically the power number is shown for mixing in fully turbulent flow.
