A new type bag filter that combines centrifugal force in existing bag filter system was developed, and its computational simulation was performed to examine characteristics on a flow field and particle behavior. The fluid coming in from the tangential direction forms strong vortex in the space between the inner and outer tube and the flow goes down along the hopper wall. Partially, this flow merges with the up-flow from the inner tube to the upper tube wall. The up-flow changes its direction at the shell plate where the bag filters are mounted and it starts to go down with a vortex along the central axis. Most of bag filters are located in down-flow region which this plays an important part to fall down to the hopper more easily when dust cake removed by cleaning.