This study installed additional inlets on the cone section of a tangential cyclone separator and examined its effect on collection efficiency and pressure drop. When aerosol was injected through the additional inlets and clean air was injected into the original inlet, the cut-off size of particles decreased, compared to that when injecting aerosol through the original inlet. However, it was revealed that there was an optimal flowrate through the additional inlets to enhance the cyclone separator's performance. Meanwhile, injecting aerosol through not only the additional inlets but also the original inlet separated a higher flowrate of aerosol while demonstrating a similar level of collection efficiency and pressure drop compared to those of the reference cyclone separator. Therefore, installing additional inlets to the cone section of a conventional tangential cyclone separator is expected to process a higher flowrate of aerosol than the separator with similar performance, thereby increasing cost effectiveness. (C) 2019 Elsevier B.V. All rights reserved.