A fan device includes a casing unit and a fan impeller unit mounted in the casing unit. The casing unit includes a casing body formed with a receiving space and an air outlet port, a porous plate formed with a plurality of through holes and is disposed in the receiving space to divide the receiving space into an air-flowing room and a noise-reduction room, and an air-entering tube in spatial communication with the air-flowing room. The fan impeller unit is disposed in the air-flowing room and rotatable to generate airflow partially flowing from the air-flowing room into the noise-reduction room through the through holes.

Volumetric resistance blowers are disclosed herein. An example volumetric resistance blower includes a housing, a motor, and a rotor disposed within the housing and rotated by the motor. The rotor is constructed of metal foam.

A centrifugal fan includes a motor, a support body, first and second rotating bodies, and a housing. The motor includes a rotor hub. The support body is fixed to and rotates together with the rotor hub. The first and second rotating bodies are continuous porous bodies and are different in material than the support body. The first rotating body is located on an axially upper surface of the support body. The second rotating body is located on an axially lower surface of the support body. The housing accommodates the first and second rotating bodies, the support body, and the motor. The housing includes a first air inlet and an air outlet. A radially inner surface of the first rotating body opposes a radially outer surface of the rotor hub with a gap interposed therebetween.

A fan impeller structure and a cooling fan thereof. The fan impeller structure consisting of a hub and a flow guide body. The hub has an extension section extending from outer circumference of the hub. The extension section has a first face and a second face. An axial center of the flow guide body is defined with an axial line. A fitting section outward extends from the axial line. A spoiler section is connected to the fitting section in a direction away from the axial line. The spoiler section is formed with multiple axial perforations that communicate with multiple radial perforations. The flow guide body is disposed on the first or second face of the extension section of the hub. The flow guide body is employed to replace the blades of conventional cooling fan. The perforations of the flow guide body can forcedly guide air in a narrow space.

The swirl flow ceiling fan has four major elements. They are: a cylindrical diffuser, an inducer, a stationary enclosure and a safety disc. As the fan rotates, the ambient air is drawn in at the centre. The air which was drawn in by the inducer further gets energised within an enclosed space. The air's velocity gets increased. The charged air is pushed into the numerous spiral compartments of the revolving cylindrical diffuser. Then, finally, the cylindrical diffuser delivers the energised air in to the space. All the features collectively provide a very efficient swirl flow of the air with lesser noise levels and better comfort. It is also found to be cost-effective in its working as well in its manufacturing.

The gas compression method/system restricts flow of emulsified liquid-gas mixture through many substantially radial capillary tube-passages in a rotating disk by either one-way valves, narrowing the passages, hydraulic impedance and/or reinforcement of coriolis forces in terminal end tail segments of the capillary passages. Compressed gas is released from peripherally collected compressed gas-liquid emulsion (beyond the terminal ends of the tubes) in a arcuate peripheral disc space when the compressed gas bubbles emerge from the peripherally collected emulsion. A compressed gas drain draws off gas from the peripheral space. Liquid drain draws off liquid from the space. In different embodiments, radial outboard flow through the capillaries is effected by various one-way valves which may be a single valve in the passage or multiple valves. Coriolis force in tail segments is enhanced by angular displacement in the direction of rotation. Valves may be used in combination with such tail-end segments.

The compressor compresses gas in capillaries leading to a radially distant annular container space. Centrifugal force acts on gas bubbles entrained between liquid slugs moving radially outward through the capillaries which may be radial, tangential or continuously curved. Compressed gas is collected in the annular space. A gas-liquid emulsion is fed to the capillaries by an inboard emulsification device. The emulsification may include a vortex generator, an ejector or a venturi injector, all feeding the gas-liquid mixture into the inboard ends of the capillaries. The capillaries are formed in a series of discs, coaxially stacked with outer disc ends open to the annular space. Capillary inlets may be perpendicular, tangential or may define a venturi jet.

Embodiments of an apparatus, system, method and techniques are described for an improved volumetric resistance blower and rotor. An apparatus may comprise, for example a motor, a casing having one or more inlets and one or more outlets, and a cylindrical rotor to create a volumetric resistance inside the casing, at least a portion of the rotor comprising a porous material. Other embodiments are described.