Calculation of Crusher for Captive Power Plant
In a captive power plant, the crusher plays a critical role in preparing fuel (typically coal or biomass) for combustion. Proper sizing and selection of the crusher ensure efficient fuel processing, minimizing downtime and optimizing power generation. Below is a detailed guide on calculating crusher capacity and selecting the right equipment for a captive power plant.
1. Determining Crusher Capacity
The crusher’s capacity depends on factors such as:
- Fuel Consumption Rate: Calculate the hourly fuel requirement based on the power plant’s thermal efficiency and calorific value of the fuel.
- Material Characteristics: Consider moisture content, hardness, and feed size distribution to determine crushing resistance.
- Operational Hours: Account for continuous or intermittent operation to avoid undersizing or oversizing the crusher.
A general formula for estimating crusher capacity (Q) is:
\[ Q = \frac{Fuel \, Consumption \, (kg/h)}{Bulk \, Density \, (kg/m³)} \times Crushing \, Efficiency \]
2. Selecting Crusher Type
Common crushers used in captive power plants include:
- Jaw Crushers: Suitable for primary crushing of large-sized coal or biomass with high compressive strength.
- Impact Crushers: Ideal for secondary crushing, producing uniform-sized output suitable for combustion.
- Roll Crushers: Effective for reducing coal to finer particles with minimal fines generation.
The choice depends on feed size, required output size, and material abrasiveness.
3. Power Requirement Calculation
The motor power (P) required for crushing can be estimated using Bond’s Law or empirical formulas:
\[ P = C \times Q \times Wi \left( \frac{1}{\sqrt{P_{80}}} - \frac{1}{\sqrt{F_{80}}} \right) \]
Where:
- \( C \) = Constant based on crusher type
- \( Q \) = Throughput capacity (tonnes/hour)
- \( Wi \) = Work index of the material (kWh/tonne)
- \( P_{80} \) & \( F_{80} \) = 80% passing size of product and feed (µm)
4. Maintenance & Operational Considerations
To ensure longevity and efficiency:
- Regularly inspect wear parts like hammers, liners, and screens.
- Monitor vibration levels to detect misalignment or imbalance