A blower in which the rotating part is equipped with blades that rotate between stationary blades attached to the housing. The respective sets of blades are set at an angle such that, as the rotor turns, gases are pushed through the blades and discharged from the opposite side, pass through the stationary blades, and then are given another push by the next set of rotating blades, finally being discharged from the casing at the opposite end from which they entered.