How Do Blowers Work?

Blowers operate by increasing the pressure of air or gas through the centrifugal motion of a rotor. The blower draws air/gas through an inlet valve, which causes the vanes or rotors to rotate. This rotational movement creates a centrifugal force, pushing the air or gas outwards. In this process, the air/gas is continuously compressed, and the pressure increases linearly.

Simply put, a blower is a device that increases the speed of the air passing through it. Blowers are designed to move air and gas from low to high pressure and are used to perform a specific function. It has a wide range of applications in many different sectors such as cooling, transportation, ventilation, and exhaust gas discharge. Blowers are used in cases where the pressure requirement is at a level between a fan and a compressor.

Blower Types

  • Positive Displacement Blowers
    Rotary Lobe Blowers
    Helical Screw Blowers
  • Centrifugal Blowers
    Multi-Stage Centrifugal Blowers
    High-Speed Blowers: Turbo

Blower Types and Operating Principles

1-Positive Displacement Blowers

Positive displacement blowers are suitable for air or neutral gas applications and have a simple operating mechanism.

✔ Air or gas enters an expanding area on one side of the blower and is discharged from a narrowing outlet.

✔ The size difference between the inlet and outlet points increases the pressure of the air, providing positive displacement.

✔ The air flow rate remains constant even if the pressure changes.

  • Rotary Lobe Blowers

A type of positive displacement blower, rotary lobe blowers operate by means of two rotors rotating in opposite directions.

✔ Air is drawn in, and the rotors rotate the air, pushing it out.

✔ Produces high-volume air flow, ideal for large vacuum systems.

✔ It is often used in aeration tanks in wastewater treatment plants and produces pressure up to 15 psi.

  • Helical Screw Blowers

✔ Can produce higher pressure compared to rotary lobe blowers.

✔ There are two rotors, each with 2-3 lobes.

✔ Helically shaped rotor lobes compress the air, providing high pressure and precise air flow.

✔ The rotors are precisely aligned so that they do not touch.

2- Centrifugal Blowers

✔ It is used in applications that require high pressure and variable air flow.

✔ Rotating impellers increase the speed of the air, increasing the outlet speed from the blower.

✔ It is widely preferred in wastewater treatment, gas transfer, and ventilation applications.

✔ Kinetic energy increases during gas passage, and pressure is balanced.

  • Multi-Stage Centrifugal Blowers

✔ Rotary machines driven by an electric motor increase the pressure of air or gas with centrifugal force.

✔ It has high pressure resistance and high flow rate.

✔ It is used in many sectors such as wastewater treatment, gas pressurization, and medical artificial lung systems.

  • High-Speed Turbo Blowers

✔ It has a high pressure of up to 25 psi and a high air flow capacity of up to 15,000 m³/hour.

✔ It is powered by motor power and has impellers that can draw air on both sides, similar to centrifugal blowers.

✔ Efficient operation is provided by providing speed control with a variable frequency drive (VFD).

Blower Selection Criteria

Selecting the right blower for a particular application requires consideration of various factors to ensure optimum performance and efficiency. Here are the key criteria to consider when selecting a blower:

Air Flow Requirements

✔ Determine the volume of air required for the application (measured in cfm – cubic feet per minute or m³/s – cubic meters per second).

✔ Evaluate the changes in air flow demand and determine whether the blower will operate at a constant or variable speed.

✔ The main factors determining air flow:

Carrying capacity

✔Distance in the transport line

✔Number of elbows in the pipeline

Pressure Requirements

✔ Determine the pressure required by the system, usually expressed in mm water column (mmWC) or Pascals (Pa).

✔ Consider static pressure (resistance to air flow) and dynamic pressure (pressure due to air velocity).

Temperature Factors

✔ Evaluate the temperature range that the air or gas will reach while being transported by the blower.

✔ Make sure that the selected blower can operate efficiently in the specified temperature range.

Altitude and Atmospheric Conditions

✔ Determine the altitude at which the blower will operate (air density varies depending on altitude).

✔ Analyze how humidity and other atmospheric factors will affect blower performance.

Application Type

✔ Select the appropriate blower type depending on the application (e.g., Centrifugal, Positive Displacement, etc.).

✔ Make the appropriate blower selection according to different application types such as ventilation, material handling, pneumatic conveying, ventilation, or aeration.

Efficiency and Energy Consumption

✔ Evaluate the energy efficiency of the blower and ensure that it meets energy consumption standards.

✔ Consider the total cost of ownership (LCC), i.e., evaluate energy consumption and maintenance costs.

✔ Select a blower with a capacity appropriate to the requirements to avoid overcapacity in transport systems and optimize energy consumption.

Operating Speed and Control Mechanism

✔ Determine the required operating speed and check whether the application requires variable speed control.

✔ Variable speed control can optimize energy efficiency by adjusting the blower's speed to the actual need.

Noise Level

✔ Evaluate the noise level produced by the blower and ensure that it complies with acceptable noise standards for the application.

✔ Generally accepted noise level limit: < 85 dB.

✔ Silencers or acoustic coatings can be used to reduce the noise level.

Installation Area and Space Limitations

✔ Evaluate the area where the blower will be installed.

✔ Make sure that the blower fits into the available space and allows for adequate ventilation and maintenance access.

Material Compatibility

✔ Verify that the materials from which the blower is manufactured are compatible with the air or gas to be transported.

✔ Select appropriate materials, especially for air/gas flows containing abrasive or corrosive components.

Reliability and Ease of Maintenance

✔ Evaluate the reliability and ease of maintenance of the blower.

✔ Pay attention to low regular maintenance and service requirements.

✔ Prefer long-lasting blowers with a reliable usage history.

Budget and Cost Restrictions

✔ Considering budget constraints, choose the blower that provides the best balance in terms of performance and cost.

✔ Blowers that provide high efficiency may be a more economical option in the long run with low energy consumption and maintenance costs.

The right blower selection ensures a more sustainable and economical solution in the long run by optimizing your business's energy efficiency and operational costs!

You can contact us for more information or technical support about blowers.