A fan assembly includes an internal housing having an outer internal housing, and an inner internal housing partially disposed within the outer internal housing. The inner internal housing defines an internal cavity, and has a curved exterior surface. Stator blades extend between the inner internal housing and the outer internal housing.

An electric blower includes an air blowing unit including a mixed-flow fan to generate a current of air, a motor to rotate the mixed-flow fan, and a housing including a first portion surrounding the mixed-flow fan in a circumferential direction, and a second portion surrounding the motor in the circumferential direction. The inner diameter of the second portion is smaller than the inner diameter of the first portion.

An electric blower includes a centrifugal impeller, a diffuser including stationary vanes on a discharge side of the centrifugal impeller, a motor configured to drive the centrifugal impeller, a fan case configured to cover the centrifugal impeller and the diffuser, a housing case joined to the fan case, and return guide vanes that guide air which has been guided by the stationary vanes to an inner surface of the fan case radially inward through a space under the diffuser. The housing case includes an annular lower plate portion located axially below the diffuser. Each return guide vane is continuous with an upper surface of the annular lower plate portion. An upper end of each return guide vane is located axially opposite to the diffuser.

An exhaust system for exhausting air from appliances in a commercial kitchen is described. The exhaust system comprises an exhaust fan that includes a housing, a motor mounted in the housing, and a fan directly driven by the motor. A motor compartment surrounds the motor. Cooling air is induced into and through the housing and directed into the motor compartment for cooling the motor. Cooling air is discharged from a motor compartment and mixed with exhaust air to form an air mixture that is directed through the housing of the exhaust fan.

A centrifugal fan is provided and includes an impeller, a motor, a first case and a second case. The motor is connected with the impeller to drive the impeller to rotate. The first case and the second case are assembled to form an accommodation space for accommodating the impeller and the motor. The first case includes a first side, a first guiding wall, a flow inlet and a flow outlet. The flow inlet is disposed on the first side, the first guiding wall is connected with the first side, and the flow outlet and the flow inlet are located at a same side of the centrifugal fan. The second case includes a second side and a second guiding wall connected with the second side. The first guiding wall and the second guiding wall are assembled to form a flow guiding channel, which has cross-sectional areas with different sizes.

A disclosed fan system includes a housing having side walls, an inflow side, and an outflow side; a fan secured in the housing by a mounting; and a backflow blocker mounted to the side walls within the housing on the outflow side of the housing partially blocking a cross-sectional area of the outflow side. The backflow blocker is positioned approximately centrally in a flow path of the housing and is configured to block part of an airflow cross section such that, between side walls of the housing and side walls of the backflow blocker, an annular duct is formed as an air passage. Further, the backflow blocker has a thickness that is greater than 5% of a width of the housing, and is less than 20% of an axial design height of the fan system.

A blower includes a body, a motor, and a single fan configured to rotate in response to rotation of a motor shaft to discharge air through a discharge opening. The maximum rotational speed of the motor shaft is within a range of 50,000 rpm to 120,000 rpm. An area of the discharge opening is changeable by a user. The blower is configured to selectively operate in a first mode or in a second mode according to the area of the discharge opening. In the first mode, the maximum blowing force of the air discharged through the opening is within a range of 2.5 N to 5.0 N when the motor is driven at the maximum rotational speed. In the second mode, the maximum dynamic pressure of the air discharged is within a range of 30 kPa to 65 kPa when the motor is driven at the maximum rotational speed.

A blower for providing a supply of air at positive pressure in the range of approximately 2 cmH.sub.2O to 30 cmH.sub.2O includes a motor, at least one impeller, and a stationary component. The stationary component includes an inlet and an outlet. The motor, the impeller, the inlet and outlet are co-axial.

A handheld fan with a fairing has a fan head and a handle. The fan head is cylindrical and is provided with an air inlet, an air outlet, and a fluid passage connecting the air inlet and the air outlet. Air inlet vanes and air outlet vanes are disposed in the air inlet and the air outlet respectively. The fan head comprises a front cover and a rear cover that are fixedly connected. A fairing is disposed on inner sides of the front cover and the rear cover. The impeller is hidden in the fan head, so users will not be cut by blades when the blades rotate; the fairing is disposed in the fan head and is provided with the air inlet vanes and the air outlet vanes, so that all components of the fan can be injection-molded and assembled easily.

A centrifugal-to-axial mixed flow blower includes a blower enclosure defining a blower chamber and a centrifugal impeller supported on an impeller seat to suspend in the blower chamber. The centrifugal impeller includes a plurality of blades and a radially outward declined flow passage defined between any two adjacent blades and communicable with the blower chamber. The blower chamber is communicable with a rectangular air outlet of a heat dissipation system via a frame passage of a flow guide frame connected to below the blower enclosure. Air stream centrifugally drawn in by the centrifugal impeller passes through the declined flow passages to radially outward and downward flow into the blower chamber and then passes through the frame passage to flow axially through the rectangular air outlet into the heat dissipation system, so as to realize the effects of reduced noise, changing centrifugal vortical flow into axial flow, and decreased flow loss.