How do you calculate impeller power?
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 are the criteria for selecting the impeller based on viscosity?
Factors to Consider When Choosing An Impeller Vessel size. Viscosity of the material you’re working with. Desired outcome of the application, for example, aeration or high shear.
How do you calculate the power of an agitator?
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. All previous steps are repeated, till correct speed is determined….Agitator Power.
| Power (P) | Np.ρ.N3.D5 | |
|---|---|---|
| P | kW | 0.851 |
What is pumping capacity of impeller?
The pumping capacity of a pitched blade impeller (PBT) is defined [1] as the amount of liquid leaving the rotor region of the impeller, i.e., the cylindrical volume circumscribed by the rotating impeller blades, per unit time.
How do you calculate flow number?
The Reynolds number (Re) of a flowing fluid is calculated by multiplying the fluid velocity by the internal pipe diameter (to obtain the inertia force of the fluid) and then dividing the result by the kinematic viscosity (viscous force per unit length).
What is impeller design?
Impeller flow designs can take on three distinct types: axial, radial, and mixed. Because centrifugal pumps are also classified in this manner, the impeller selection depends upon matching the pump’s flow characteristic to that of the impeller. Axial flow impellers move media parallel to the impeller.
How do you select an impeller type?
The size of vessel used for mixing will determine the diameter of the impeller. A general rule of thumb for axial or radial flow patterns is the diameter of the impeller be ⅓ of the vessel’s diameter, so a 10 cm beaker would require approximately 3 cm impeller.
How do you calculate torque for agitator?
Nq = Q / ( N x D x D x D), Agitator Speed , N =Q / ( Nq x D x D x D ), From this Agitator Speed, calculate the Reynold’s Number, Nre = D x D x N x rho / myu.
How do you calculate the RPM of a reactor?
Reactor – 1: L / D = 2 / 1.5 = 1.33, d / D = 1.2 / 1.5 = 0.8, Reactor – 2: L / D = 2.5 / 1.88 = 1.33, d/D = 1.5 / 1.88 = 0.8. So if Reactor – 1 is operated with 48 RPM, then simply adopt 48 RPm to Reactor – 2 also….Reactors Scale-up:
- Shaft speed,
- Tip speed,
- Reynolds number,
- Froude number,
- Power per unit volume.
How do you calculate pump impeller size?
Impeller sizes are determined by calculating the TOR (sometimes called time of rollover) for each compartment. This is the time, in seconds, required to completely move the fluid in a compartment (Table 4.1), and can be calculated by knowing the tank volume and impeller displacement: Table 4.1.
How do you calculate pump flow rate?
Submersible pump flow calculation formula: 60HZ flow × 0.83 = 50HZ flow 60HZ lift × 0.69 = 50HZ lift 60HZ power ÷ 1.728 = 50HZ motor power motor output power = Q (flow) × H (head) / 367.2 / efficiency × 1.15 motor output power = shaft power × 1.15 pump efficiency = Q × H × 0.00272 / motor power Q represents flow; H …
What is a Rushton impeller?
The Rushton impeller, named after its designer, is one of the first mixing impeller designs to be documented. The classic design of this impeller provides a simple radial flow pattern that moves material from the center of the vessel outward where it flows along the outer walls of the tank.
How do Rushton turbine impellers interact with each other?
As indicated in Figure 8.37, the radial flow pattern generated by Rushton turbines creates separate circulation currents above and below each impeller, providing little opportunity for interaction between the fluid streams emanating from different impellers.
What is the power draw of a Rushton turbine?
Rushton turbines have a relatively high power number. However, if the Rushton is replaced by an impeller with a lower power number then the power draw will be less or a larger impeller may be used to replace the Rushton at the same power draw.
What is a radial impeller?
The classic design of this impeller provides a simple radial flow pattern that moves material from the center of the vessel outward where it flows along the outer walls of the tank. It is most commonly used in reactor tanks, two phase mixing (liquid/gas), and any application requiring INTENSE mixing with high power per volume.