The disclosure relates to an electric blower apparatus having a blower spiral which has a first axial end wall, a second axial end wall and a blower air outlet. An electric motor which drives a fan wheel rotating in the blower spiral is held on the first axial end wall, the fan wheel inducting ambient air by way of an intake opening in the second axial end wall. A cover element, the cover surface thereof being configured so as to be larger than the air inlet surface of the intake opening, is disposed in front of the intake opening. To induct a large quantity of ambient air with little noise, it is provided that the cover element is configured as a cover plate, wherein an annular gap which forms the intake channel for the direct access of ambient air is configured between the plate edge and the blower spiral.

A fan comprises a fan housing which includes a shroud having an upstream end that defines an inlet of the fan housing, a motor which is connected to the fan housing, and an impeller which is connected to the motor. The impeller includes an impeller hub and a number of impeller blades which extend radially outwardly from the impeller hub. The shroud includes a cylindrical micro-perforated panel (“MPP”) liner which extends axially from proximate the inlet to proximate the impeller.

The invention relates to an exhaust gas turbocharger with a silencer. The silencer comprises a multiplicity of damping elements which are arranged concentrically about a central axis of the silencer and are spaced apart concentrically from one another, with the result that a flow duct is formed in each case between adjacent damping elements. The flow duct has an inlet which is at a greater radial spacing from the central axis than an outlet of the flow duct.

A noise reduction method of a ventilator, comprising the following steps: S1 starting a ventilator and imputing a required wind pressure d at a man-machine interface, and then sending a signal to an actuator through a processor, and adjusting a first blade automatically to a maximum adjustable angle state a′° through the actuator and a second blade to a minimum adjustable angle state b°; S2 regulating a revolution speed, when a wind pressure is d, feeding back a revolution speed c, a conducting noise e.sub.1 and a radiated noise f.sub.1 to the processor through an acquisition device, and after the processor receives a revolution speed information, sending a command to lock the revolution speed to the actuator through the processor. The present disclosure can effectively solve the poor noise reduction function of the present noise reduction hoop, and can effectively reduce the cost and simplify the installation process.

A fan array fan section in an air-handling system includes a plurality of fan units arranged in a fan array and positioned within an air-handling compartment. One preferred embodiment may include an array controller programmed to operate the plurality of fan units at peak efficiency. The plurality of fan units may be arranged in a true array configuration, a spaced pattern array configuration, a checker board array configuration, rows slightly offset array configuration, columns slightly offset array configuration, or a staggered array configuration.

An air blower has an inlet muffler and an outlet muffler to reduce the noise of the air blower during operation. Each of the mufflers may have two sections. One section is configured to attenuate high frequency noise and the other section is configured to attenuate lower frequency noise. A tubular internal wall in each of the mufflers defines the through passage for each of the mufflers. A noise absorbent material may be fitted about the tubular wall within each muffler. A plurality of holes are formed along the tubular wall of each through passage to expose the through passage to the noise absorbent material. A heater plenum may be interposed between the blower plenum and the outlet muffler to heat the air from the blower plenum. A filter at the input muffler filters the air sucked into the air blower.

The utility model relates to a noise reduction device for an outlet side of a fan, and a heat exchange system including the noise reduction device. The noise reduction device includes: a connecting portion configured to be connected with at least a part of the air duct cover, and form an accommodation space communicating with an airflow on the outlet side via at least one of the through holes; and at least one first chamber and/or at least one second chamber, the first chamber being located in the accommodation space and filled with a sound-absorbing material, and the second chamber being located in the accommodation space and configured as a resonant noise-reduction cavity. The utility model is easy to manufacture, install and maintain, the noise reduction effect is obvious, and therefore the utility model has significant practicability.

A blower unit can include an outer housing, an inlet subassembly, a fan subassembly, an outlet subassembly, and a grommet. The outer housing can have an aperture extend along a first axis between first and second ends. The inlet subassembly can be received in the first end of the aperture. The fan subassembly can be received in the aperture adjacent to the inlet subassembly and include at least one wire. The outlet subassembly can be received in the second end. The grommet can be positioned between at least part of the second end and the outlet subassembly. The at least one wire can extend through the grommet. The grommet can seal against the at least one wire. The grommet can seal between the outer housing and the outlet subassembly.

A modular fan housing configured to hold an array of motors and fans is provided. The modular fan housing is configured for use in an air-handling system that delivers air to a ventilation system for at least a portion of a building. The fan housing comprises a plurality of modular units configured to be stacked adjacent to one another in at least one row or column to form an array. The modular units each include an interior surface and have a front end and a back end that define a chamber. The chambers are configured to receive the motors and fans. Sound attenuation layers extend along at least a portion of the interior surface of the corresponding chambers. The sound attenuation layers are positioned between at least some of the adjacent chambers.

A fan housing of a turbofan engine that forms an internal space surface at the inner side, delimiting a flow path through the fan of the turbofan engine radially outside, wherein the fan housing has a beginning of the housing that is arranged upstream. It is provided that a divergent cross-sectional surface extension of the flow path is realized by the internal space surface of the fan housing where it directly adjoins the beginning of the housing, and that the internal space surface of the fan housing is suited for continuously extending an inlet diffuser of an engine inlet, which is arranged upstream of the fan housing, into the area of the fan housing. The invention further relates to an engine assembly with a fan housing and an engine inlet.