A single-stage steam ejector is designed to remove 50 kg/h of air from a reflux drum operating at 25 kPa and 50°C and discharge it to the atmosphere through a vent using a steam ejector with saturated steam at a pressure of 1 MPa. After the system has been designed, it is found that the pressure in the reflux drum has risen to 30 kPa (still at 50°C). Estimate the additional air flowrate (due to leakage) that is responsible for the increase in reflux drum pressure.