Abstract: A cyclone comprising a cylindrical portion and an inverted conical portion, the cylindrical portion having a gas inlet connected thereto in its tangential direction and a gas outlet perforated through a ceiling panel thereof, the gas inlet allowing the introduction of a gas including powders therethrough, the inverted conical portion being connected to the cylindrical portion under its lower edge and having a collected powder outlet at the lower end thereof, characterized in that the gas outlet is perforated through the ceiling panel of the cylindrical portion so that the central axis of the gas outlet may be coaxially coincident with the central axis of the cylindrical portion; a cylindrical exhaust gas guide is disposed under the ceiling panel so as to surround the periphery of the gas outlet; and when a cross section of the cylindrical portion is separated into four sectors by an imaginary line passing through an intersection of an inner wall of the gas inlet and the cylindrical portion and passing through

Abstract: There is provided a cyclone which has a guide plate for conducting a fluid into a fluid-discharge pipe, the guide plate taking the place of a portion of a fluid-discharge pipe extending vertically downwardly in the main body of the cyclone. The fluid-discharge pipe has any shape of its own in cross section. This cyclone may include a fluid-discharge pipe installed in a position away from the center of main body of the cyclone and inclined against the direction of central axis of the cyclone.