: Account for efficiency losses. Typically, you should add a gland loss (approx. 10%) and transmission/gearbox loss (approx. 20%) to the calculated agitation power. Tank agitator power calculation - My Engineering Tools
| Output | Value | Acceptable Range | |--------|-------|------------------| | Reynolds number | 94,500 | >10,000 (Turbulent) | | Agitator power | 4.0 kW | – | | Shaft diameter | 35 mm (selected) | ≥32 mm | | Motor selected | 5.5 kW, 1500 rpm | Yes | | Critical speed ratio | 380 / 150 = 2.53 | >1.3 (Safe) |
Example row: Rushton Turbine | Po=5.2 | Nq=0.72 | Gas dispersion
Not all power is used equally. The pumping number defines the bulk fluid velocity:
The fluid dictates the resistance the agitator faces.
| Parameter | Symbol | Unit | Example Value | |-----------|--------|------|----------------| | Vessel diameter | Dt | m | 1.5 | | Liquid height | Hl | m | 1.8 | | Impeller diameter | Da | m | 0.6 | | Impeller type | – | – | Turbine (6-blade) | | Rotational speed | N | rpm | 150 | | Liquid density | ρ | kg/m³ | 1050 | | Liquid viscosity | μ | Pa·s | 0.5 | | Number of impellers | – | – | 1 | | Baffles present? | – | – | Yes |
: Account for efficiency losses. Typically, you should add a gland loss (approx. 10%) and transmission/gearbox loss (approx. 20%) to the calculated agitation power. Tank agitator power calculation - My Engineering Tools
| Output | Value | Acceptable Range | |--------|-------|------------------| | Reynolds number | 94,500 | >10,000 (Turbulent) | | Agitator power | 4.0 kW | – | | Shaft diameter | 35 mm (selected) | ≥32 mm | | Motor selected | 5.5 kW, 1500 rpm | Yes | | Critical speed ratio | 380 / 150 = 2.53 | >1.3 (Safe) |
Example row: Rushton Turbine | Po=5.2 | Nq=0.72 | Gas dispersion
Not all power is used equally. The pumping number defines the bulk fluid velocity:
The fluid dictates the resistance the agitator faces.
| Parameter | Symbol | Unit | Example Value | |-----------|--------|------|----------------| | Vessel diameter | Dt | m | 1.5 | | Liquid height | Hl | m | 1.8 | | Impeller diameter | Da | m | 0.6 | | Impeller type | – | – | Turbine (6-blade) | | Rotational speed | N | rpm | 150 | | Liquid density | ρ | kg/m³ | 1050 | | Liquid viscosity | μ | Pa·s | 0.5 | | Number of impellers | – | – | 1 | | Baffles present? | – | – | Yes |
