Gas Flow Rates - Orifice Size vs Pressure

This table provides crucial data for combustion engineers, particularly those working with natural gas systems. The figures in the table represent the gas flow rates (in cubic metres per hour, C.M.H.) for various jet diameters (in millimetres) and jet areas (in square centimetres) at different gas pressures (measured in millibars, mbar).

How to Use the Table:

1. Jet Diameter and Area: The leftmost columns list the jet diameter and the corresponding jet area. Engineers can select the appropriate jet size for their application.
2. Gas Flow Rates: The values across the table indicate the gas flow rates at different pressures. These figures help in determining the optimal flow rates needed for efficient and safe combustion processes.

Key Points:

• Discharge Coefficient: The table assumes a discharge coefficient of 0.9, which is a standard measure indicating the efficiency of gas discharge through the jet.
• Gas Specific Gravity: The table uses a specific gravity of 0.6 for natural gas, ensuring the values are accurate for typical natural gas compositions.

Practical Applications:

• Burner Design: Engineers can use this data to design and optimise burners, ensuring they deliver the correct amount of gas for efficient combustion.
• System Calibration: When setting up or maintaining gas systems, this table aids in calibrating equipment to the correct flow rates based on the operating pressure.
• Safety and Efficiency: Accurate gas flow measurements are critical for maintaining both the safety and efficiency of combustion systems. This table provides a reliable reference to achieve these goals.