A fan is a motor-driven device capable of creating air or other gas flows. Today, a wide variety of types of these devices are presented, for example, centrifugal fans are in demand in industry.
Specifications, power, dimensions, noise and other parameters depend on the type of device and the purpose of its use.
The following main types of instrument designs are used in air conditioning and ventilation systems.
Axial are arranged in such a way that the air flow moves along the axis of rotation of the wheel. These types are often used to create air exchange systems.
Centrifugal or radial fans create conditions under which air flows enter along the axis of movement of the wheel, and exit the device inradial plane. This type is widely used in ventilation installations.
Diameter fixtures allow flow to enter and exit perpendicular to wheel rotation.
According to the force of the generated pressure, all devices are divided into a fan (radial) of medium pressure, low and high.
The most widely used centrifugal devices.
Centrifugal fans consist of a bladed impeller that is housed in a helical casing. During rotation, the wheel directs the air between the blades along the path from the center, while simultaneously compressing it. The centrifugal force acting during rotation throws the compressed air into the casing, from which it flies out to the discharge port.
The main part of the device is the impeller. It is most often produced in the form of a hollow cylinder with blades on the outside. The blades are set parallel to the axis of rotation at regular intervals. Their fastening in front and behind is carried out by means of two disks, in the center of which there is a hub used to fit the engine onto the shaft.
A radial fan in its design may have backward or forward curved blades, the number of which is determined by the type and functional purpose of the device.
Industrially, devices are produced with eight positions of the spiral casing, with right orleft-handed spiral direction.
Central fans, actively used in air conditioning and ventilation systems, are responsible for the quality of air exchange.
Depending on the type and purpose of the system, centrifugal devices with one- or two-sided suction are installed, as well as devices with V-belt drives, devices located with the drive motor on the same shaft.
In addition, low-pressure radial fans are used with the direction of the blades bending in different directions in the direction of travel. Curved blades allow you to reduce electricity consumption by almost 20 percent when installing the device. It is also advisable to use them in modes when air consumption is carried out with an overload.
