A cyclone unit is for separating liquid and particles from a suction flow. A main flow inlet to the outer housing of the cyclone unit includes an opening. The transition between the main flow inlet and the outer housing at this opening has, at least for a portion of the opening, a radius of curvature of at least 0.5 mm. The large radius of curvature prevents the formation of static water drops.

A cyclone unit is for separating liquid and particles from a suction flow. A main flow inlet to the outer housing of the cyclone unit includes an opening. The transition between the main flow inlet and the outer housing at this opening has, at least for a portion of the opening, a radius of curvature of at least 0.5 mm. The large radius of curvature prevents the formation of static water drops.

A wet vacuum cleaner uses a cyclone unit for separating liquid and particles from a suction flow. A main flow inlet to a cyclone chamber is spaced internally from its respective end by a separation distance. The separation distance is at least 0.1 times (effective/equivalent) diameter of the main flow inlet, which assists in preventing formation of large droplets which follows a path to a main flow outlet.

A wet vacuum cleaner uses a cyclone unit for separating liquid and particles from a suction flow. A main flow inlet to a cyclone chamber is spaced internally from its respective end by a separation distance. The separation distance is at least 0.1 times (effective/equivalent) diameter of the main flow inlet, which assists in preventing formation of large droplets which follows a path to a main flow outlet.

According to one implementation, a centrifugal oil mist separator includes a duct, a fan and a power transmission mechanism. The duct forms a flow path of a first exhaust gas discharged from an engine. The first exhaust gas includes oil mist. The fan is disposed inside the duct. The power transmission mechanism rotates the fan using energy of a second exhaust gas discharged from the engine. The second exhaust gas includes no oil mist.

According to one implementation, a centrifugal oil mist separator includes a duct, a fan and a power transmission mechanism. The duct forms a flow path of a first exhaust gas discharged from an engine. The first exhaust gas includes oil mist. The fan is disposed inside the duct. The power transmission mechanism rotates the fan using energy of a second exhaust gas discharged from the engine. The second exhaust gas includes no oil mist.

A uniflow cyclone for a hand vacuum cleaner has a dirt chamber that is external to the cyclone chamber and vortex finder, which has a solid portion that is spaced from and faces a dirt outlet of the cyclone chamber and a porous section that is angularly spaced around the cyclone axis of rotation of the cyclone from the solid portion.

A uniflow cyclone for a hand vacuum cleaner has a dirt chamber that is external to the cyclone chamber and vortex finder, which has a solid portion that is spaced from and faces a dirt outlet of the cyclone chamber and a porous section that is angularly spaced around the cyclone axis of rotation of the cyclone from the solid portion.

A cyclone for a hand vacuum cleaner has an outlet port that is sized to produce an annular flow band in the cyclone which extends radially inwardly to overlap the solid sidewall of the vortex finder.

A cyclone for a hand vacuum cleaner has an outlet port that is sized to produce an annular flow band in the cyclone which extends radially inwardly to overlap the solid sidewall of the vortex finder.