Abstract: In a centrifugal type blower unit, a diameter of an air suction port is set to be larger than a minimum inner diameter of a centrifugal fan, and a slanting portion is formed in each blade of the centrifugal fan at a side of the air suction port so that an inner radius dimension of the centrifugal fan is increased toward the air suction port. Therefore, it can prevent sub-flow air which is sucked into the centrifugal fan from an end side of the blades in an axial direction from interfering with main-flow air which is sucked into the centrifugal fan from an inner radius side of the blades. Thus, the blower unit can reduce second noise generated therefrom without greatly reducing air-blowing capacity.

Abstract: An extracting blower that removes liquid and solid contaminants from supply air, and provides high velocity air for cooling equipment, personnel and/or structures. The blower uses air velocity and the centrifugal force of a rotating fan to separate the contaminants into a rear partitioned chamber of the fan housing and out a rear scavenging air exhaust, while blowing clean air out the main air blower.

Abstract: Improvement is made to the shape of blades of a fan assembly for sucking air into an annular wall through slits in the wall, in order to increase the aerodynamic performance and energy efficiency. In the fan assembly for sucking air in through slits provided in an annular wall (2), the blade tips of an axial fan (21) are bent in the rotating direction to smoothly take in air flowing in through the slits. The axial fan is formed so that the blades except the tips thereof are in a shape of a radial or a rearward tilting blade. The angle formed by the blade forward tilting angle near the blade tip of the axial fan and the slit angle is between −5 and 15°, and the blade tip is bent in the wind blowout direction. This configuration improves the P-Q characteristic, reduces noise and improves energy efficiency.

Abstract: A wave augmented diffuser for a centrifugal compressor surrounds the outlet of an impeller that rotates on a drive shaft having an axis of rotation. The impeller brings flow in in an axial direction and imparts kinetic energy to the flow discharging it in radial and tangential directions. The flow is discharged into a plurality of circumferentially disposed wave chambers. The wave chambers are periodically opened and closed by a rotary valve such that the flow through the diffuser is unsteady. The valve includes a plurality of valve openings that are periodically brought into and out of fluid communication with the wave chambers. When the wave chambers are closed, a reflected compression wave moves upstream towards the diffuser bringing the flow into the wave chamber to rest. This action recovers the kinetic energy from the flow and limits any boundary layer growth. The flow is then discharged in an axial direction through an opening in the valve plate when the valve plate is rotated to an open position.

Abstract: In a blower in which air is sucked to the inside through slits formed in an annular wall, the width w and the number of slits are so set that an air flow of 20 to 40% of the maximum air flow is sucked through the slits in a state in which the static pressure is zero. By this configuration, the fan stall inhibiting effect due to the air flow through the slits and the energy loss due to the viscosity of air yielded in the slits are balanced, whereby the efficiency of the blower can be improved.

Abstract: A fan wheel includes a main body and an axle connected to a center of the main body. The main body includes a peripheral wall provided around an axial axis thereof. A number of upper blades and lower blades are mounted to the peripheral wall. Each upper blade extends in a direction at an angle with the axial axis, while each lower blade extends in a direction substantially parallel to the axial axis. When the main body rotates, the axial blades drive air along the axial axis, and the blower blades drive air along a plane perpendicular to the axial axis.

Abstract: A blower comprising an annular wall (2) formed to be spaced from blade tips of a fan (1), the annular wall having slits (6) formed at a portion opposed to the blade tips to establish communication between inner and outer peripheral portions of the annular wall, so that air is sucked into the inner peripheral portion of the annular wall through the slits as the fan rotates, characterized in that the width w of a gap of the slit is changed in radial and circumferential directions thereof, whereby the quantity of air flowing into the inner peripheral portion of the annular wall through the slits is made substantially equal over the entire circumference. By this configuration, leakage vortexes flowing from the pressure side to the suction side at the blade tips are restrained, and the P-Q characteristics are improved. At the same time, noise produced in the annular wall having slits can be restrained, so that a low-noise blower can be realized.