Subtopic: Functional requirements, principles of working, construction and operation of manual, animal, tractor and renewable energy operated equipment for tillage, sowing, planting, fertilizer application, inter-cultivation, spraying, mowing, chaff cutting, harvesting and threshing
Question Statement:
A 6-row pneumatic precision planter has a vacuum blower that evacuates air from 6 metering discs simultaneously. The total airflow rate required is $Q = 0.08\text{ m}^3/\text{s}$ at a differential vacuum pressure of $\Delta P = 4.5\text{ kPa}$. If the overall fan-blower efficiency is $\eta_b = 60\%$, the power required to drive the blower from the tractor PTO in $\text{W}$ is ________ (round off to integer).
Answer Key:
600
Step-by-Step Solution & Explanation
```
Planter Blower Power Calculation:
Air Flow: Q = 0.08 m^3/s
Vacuum: Delta P = 4.5 kPa = 4500 Pa
Efficiency: eta = 0.60
```
**Step-by-step Calculation:**
1. Theoretical pneumatic air power ($P_{\text{air}}$):
$P_{\text{air}} = Q \times \Delta P = 0.08\text{ m}^3/\text{s} \times 4500\text{ N/m}^2 = 360\text{ W}$
2. Shaft power required with blower efficiency $\eta_b = 0.60$:
$P_{\text{shaft}} = \frac{P_{\text{air}}}{\eta_b} = \frac{360\text{ W}}{0.60} = 600\text{ W}$