Вентиляторы: «Commercial rotary blowers»

Commercial rotary blowers

Besides the unclear and unknown name to many rotary blowers probably know everyone.  These devices, which look like a snail, are an essential component of most air conditioning and heating systems. We have devoted this text to the description of the principle of operation of rotary blowers, their scope of application and maintenance of this equipment.

What are the components of a rotary blower?

The so-called "snail" of the blower has two holes: input and output. From the air intake located on the side, the flow enters the spiral blades of the rotating wheel and, continuing its movement in a spiral inside the casing, breaks out through the outlet. The latter is usually directed upwards. The rotary blower is named because the working substance in it moves under the action of the usual centrifugal force, which is described in physics lessons at school.

The wheel with blades is mounted on a shaft with bearings and placed in the frame. The wheel consists of front and rear discs, blades and a hub. It is interesting to note that the blades can occupy different positions in relation to the direction of rotation. If the blades are bent back ‒ we have a more productive and more economical device (with a higher speed of rotation of the shaft). If forward, the speed will be lower, but the noise from such a car will be less. The direction of rotation of the shaft also can vary. When you rotate clockwise (relative to the axis looking into the air intake), you get a fan of the right rotation, in the opposite direction – the left. In terms of power, all devices are divided into three groups, depending on the pressure inside the casing:

- Group I: up to 1000 PA. (low pressure fan).

- Group II: 1000-3000 PA. (medium pressure).

- Group III: 3000 -12000 PA. (high pressure).

The power source for the unit is an electric motor.

Where can rotary blowers be applied?

Being made of aluminum alloys and equipped with an engine with a low probability of sparking, rotary blowers are well suited for moving explosive air mixtures, including those with a high concentration of water vapor. The upper limit of the air mixture temperature is +80 degrees Celsius. Rotary blowers are not suitable for moving an air mixture with any significant content of dust, sticky and fibrous materials, as well as particles from explosives.

Rotary blowers` maintenance

An important advantage of these units is the relative ease of maintenance. This applies to configuration, regular maintenance and repair. For example, a daily inspection involves monitoring such parameters as the oil level and the absence of its leakage, the radial range of bearing vibrations, and the serviceability of the drive and control mechanism. An experienced specialist copes with this task almost immediately.