WHAT IS THE FUNCTION OF AN AIR BLOWER?

THE PRINCIPLES OF AIR BLOWERS

To create a vacuum, an air blower employs a rotating impeller/rotor. This vacuum forces air into the blower. The air enters the impeller's center and is divided by the revolving blades. Centrifugal force accelerates the air and expands the volume of the air stream within the housing.

The kinetic energy of the impeller is effectively transmitted to the air. As the volume of the airstream inside the housing grows, pressure builds up. The air is then expelled from the housing to a predetermined location.

This specialized air channeling is what distinguishes an air blower from a standard fan. Air blowers, when used in conjunction with an air knife system, will produce balanced airflow, reducing wasteful over-generation of surplus volume and pressure.

CURVED CENTRIFUGAL AIR BLOWERS FORWARD

Centrifugal air blowers can transport large amounts of air at low pressure, saving up to 90% over compressed air. This is how and why...

The air velocity (in metres per second) in a blower is constant. But the mass flow rate (the number of kilos of air passing a specific place per second) is not fixed. Centrifugal air blowers operate at lower pressure because they may consume less air to achieve the requisite high-velocity airstream.

Lower pressure equals lower energy expenses – for the same (or better) performance.

The impellers in forward curved centrifugal air blowers look a lot like hamster wheels. And as risible as it may sound, it’s certainly the finest visual description. It’s not one you’re likely to forget.

These are some of the most common air blowers - providing medium amounts of pressure from a medium level of power. The impellers can be either left- or right-handed to suit the application.

Which is better? Left- or right-handed? It depends on the application and where it is most advantageous for the motor to sit in respect to the discharge.

Check out our selection of forward curved centrifugal fans. More than 550 fans are available in our portfolio to satisfy the needs of a wide range of industrial applications.

Before making any decisions, please consult with us.

Forward Curve Fan Selection

CENTRIFUGAL BACKWARD CURVED AIR BLOWERS

Backward curved blowers, like forward curved blowers, provide'mid power, medium pressure' performance. Backward curved blowers, on the other hand, feature a more durable impeller and fewer sloping blades.

Backward-curved blades flick rather than cut the air. As a result, size for size, they supply more air at lower pressure. This means more performance for less electricity (if the application requires it). Centrifugal? 'Centri-frugal' is a better description.

They are not only more energy efficient, but also quieter. As a result, they are widely employed in air conditioning systems and data center cooling. Some were also featured in Walking With Dinosaurs - The Arena Spectacular, based on the BBC's multi-award-winning TV mini-series.

Check out our selection of backward curved centrifugal air blowers. Direct impeller installation and moderate motor speeds provide high-pressure performance with low noise levels.

Centrifugal Fan with Backward Curve for Air Knife Application

BLOWERS WITH A BACKWARD INCLINE

A distinct type of impeller is used in backward inclined aerofoil blowers, such as the belt-driven EP10A. This style of blower has a flatter rotor, making it more compact.

But don't be fooled by their diminutive size; they're engineered to blast out medium amounts of air at tremendous pressure. The EP10A, in particular, boasts a cutting-edge impeller design and improved belt technology, resulting in less friction. The tension of the belt is also reduced, putting less strain on the bearings and extending their life.

EP10A blowers can be found in our LNL (Low Noise Level) fully enclosed air knife systems as well as our EL partially enclosed air knives.

Belt-driven air knife enclosure blower

These are really tough blowers. They are especially appropriate for marine/offshore applications as well as hot/cold conditions. They're not quite 'fit and forget,' but they're tough blowers.

Like the paddles on an antique Mississippi steamboat, the impeller blades radiate from the center to the outside edge. These blades are typically sandwiched between protective layers, resulting in increased strength and more efficient air flow.

ACI's radial fans have flow rates as high as 212,000 m3/hr (360,000CFM) and pressures as high as 300 Mbar (120 In.Swg).

These high-volume, low-pressure units have impellers that resemble desk fans. They are ideally suited to chilling vast volumes of air at a low cost.

They can be found in wind tunnels and some HVAC systems (but not in large ducted systems because they are low-pressure fans). They're also useful for destratification in buildings, which involves mixing air to prevent stratified strata of heat from becoming trapped near the ceiling.

Euroventilatori axial fans are available from ACI with flow rates of up to 75,000 m3/hr (44,143 CFM) and static pressures of up to 3 In.Swg (75 mmWG).

WHY DOES IT PAY TO SEEK EXPERT TECHNICAL ADVICE?

The impeller and housing design of an air blower can have a significant impact on its performance. Consider the following factors:

The form, angle, and configuration of the blades - the kind and size of the impeller. Larger diameter impellers generate more pressure, whereas broader (deeper) impellers provide more airflow.

The distance between the impeller and the cut-off point (the point at which air exits the housing). This is critical for success.

The amount of heat produced by the air blower (due to the higher pressure of the air) - the temperature differential can range from 3°C to 20°C.

What is the climate like where the air blowers will be used? What temperature is it? How high will the blowers be used? (Thinner air is more difficult to move).

Multiple blower configuration: will they be utilized in series (stacked) or parallel (side by side)? Stacking fans in series adds strain.

There is also the question of how the blowers are wired. Because a blower is not a pump, you will only receive around 60% of the performance at best if you get it incorrectly.

Our field engineers occasionally come across blowers that have been improperly wired in a three-phase supply, resulting in drastically reduced airflow output.