The filter cleaning performance of different air injection nozzles installed in a pulse-jet bag filter dust collector were compared. The examined nozzles were a hole nozzle, a nipple nozzle, and a dual-slit injector. The latter is an air injection nozzle with two circumferential slits, which was newly designed in this study to introduce large volumes of cleaning air with a small amount of compressed air, thereby significantly improving the filter cleaning efficiency. When the dual-slit injector was applied under a 2.0 m/min filtration velocity, superior filter cleaning performance and lower dust emission were observed compared to those for the hole and nipple nozzles. In addition, there was little difference in filter cleaning efficiency according to pulsing air pressure, indicating that low and high pulse pressures can yield similar levels of filter cleaning performance when the dual-slit injector is employed; thus, the pulsing energy for filter regeneration can be reduced. Under a 4.0 m/min filtration velocity, neither the hole nor nipple nozzle yielded effective filter cleaning, generating a higher pressure drop and a significantly reduced pulse jet cleaning interval. On the other hand, the dual-slit injector applied to the pulse-jet bag filter maintained stable filter cleaning performance, even under the high filtration velocity. (C) 2017 Elsevier B.V. All rights reserved.