A fan is a motor - driven device capable of generating flows of air or other gases. Today, a wide variety of types of these devices is presented, for example, radial fans are in demand in industry.
Technical characteristics, power, dimensions, noise and other parameters depend on the type of device and the purpose of its use.
In air conditioning and ventilation systems, the following main varieties of instrument designs are used.
Axial are arranged so 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 in a radial plane. This type is widely used in ventilation installations.
Diametric devices provide entry and exit of the flow perpendicular to the rotation of the wheel.
By the force of the created pressure, all devices are divided into a fan (radial) of medium pressure, low and high.
The most common are centrifugal devices.
Radial fans consist of a blade impeller, which is in a spiral-shaped casing. During rotation, the wheel directs the air located between the blades along the path from the center, while at the same time it is compressed. The centrifugal force acting during rotation throws compressed air into the casing, from which it flies out to the discharge hole.
The main part of the device is the impeller. It is most often produced in the form of a hollow cylinder having scapulae on the outside. The blades are mounted 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, which is used to mount the engine on the shaft.
A radial fan in its design may have vanes bent back or forward, the number of which is determined by the type and functionality of the device.
Industrial devices are manufactured with eight positions of the spiral casing, with right- or left-sided direction of the spiral.
Radial 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, radial fans of low pressure are used with the direction of bending of the blades in different directions in the direction of travel. Curved blades allow the installation of the device to reduce electricity consumption by almost 20 percent. It is also advisable to use them in modes when air consumption is made with overload.