calculation to design ilms in coal handling plant
Calculation Methods for Designing Integrated Load Monitoring Systems (ILMS) in Coal Handling Plants
Designing an Integrated Load Monitoring System (ILMS) for a coal handling plant requires precise calculations to ensure efficient material flow, equipment safety, and operational reliability. The system monitors conveyor belt loads, detects imbalances, and prevents overloading or spillage. Below are key steps and formulas used in the design process.
1. Determining Conveyor Belt Capacity
The primary function of ILMS is to monitor the load on conveyor belts. The capacity of a conveyor belt is calculated using:
\[ Q = 3600 \times A \times v \times \rho \]
Where:
– \( Q \) = Conveyor capacity (tons/hour)
– \( A \) = Cross-sectional area of material on the belt (m²)
– \( v \) = Belt speed (m/s)
– \( \rho \) = Bulk density of coal (tons/m³)
The cross-sectional area (\( A \)) depends on the troughing angle and belt width. For a three-roll idler setup with a troughing angle of 35°, the approximate area can be estimated using empirical formulas or standard tables based on belt width.
2. Calculating Idler Spacing Based on Load
Idler spacing must be optimized to prevent excessive sagging under load. The maximum sag (\( S_{max} \)) should not exceed 1–2% of the span length (\( L \)). The required idler spacing (\( S \)) is derived from:
\[ S = \sqrt{\frac{8 \times T_0 \times S_{max}}{w_b + w_m}} \]
Where:
– \( T_0 \) = Initial belt tension (N/m)
– \( w_b \) = Weight of belt per unit length (kg/m)
– \( w_m \) = Weight of material per unit length (kg/m)
Excessive spacing increases belt wear, while insufficient spacing raises maintenance costs. Typical spacing ranges from 1–1.5 meters for heavy-duty applications.
3. Selecting Load Cells for Weighing Systems
Load cells measure the force exerted by coal on weighbridges or idlers. The required load cell capacity depends on the total load per idler set:
\[ F_{total} = (w_b + w_m) \times g \times S \]
Where:
– \( g \) = Acceleration