Selecting the Right Blower for Your Application

Blowers are devices that move air or gas from one location to another using impellers. These machines use more power than fans and are helpful in situations where more precise and directed airflow is required. 

Gas naturally flows from regions of higher pressure to lower pressure, and blowers create a pressure differential in order to transport gas or air. To establish flow, the blower’s discharge pressure must be greater than the system pressure.

Three common types of blowers are rotary positive displacement blowers, regenerative blowers, and centrifugal blowers. These blowers are used in a number of industries and applications, and it can be overwhelming at first when trying to select the right one for you. Understanding their differences can help you find one that is best suited to your needs.

Rotary Positive Displacement Blowers

Rotary positive displacement blowers, or PD blowers, trap a fixed volume of gas or air and push it from one side to the other. Inside PD blowers, two-lobe or three-lobe impellers that are positioned on parallel shafts rotate at equal speeds in opposite directions. 

One lobe impeller, which is known as the “driving rotor”, is powered by an external source such as an AC motor. The other lobe impeller is called a “driven rotor” and is turned by timing gears connected to the driving rotor.

As the blower spins, the lobes draw in gas or air from the inlet of the blower and carry it around the casing to the outlet. PD blowers move the same volume of air at each turn regardless of pressure changes, and this consistency is where the term positive displacement comes from. Timing gears keep the lobes synchronized, leaving small spaces and preventing the need for lubrication inside the lobe cavity.

There are many applications and industries that commonly use PD blowers. A few examples of these industries include chemical, food and beverage, power and energy, and water and wastewater treatment.

PD blowers are used for various applications, including:

  • Aeration
  • Dust collection
  • Fluidization 
  • Pneumatic conveying
  • Vapor recovery

One particularly common application of PD blowers is pneumatic conveying. Pneumatic conveying systems are used to move materials in bulk, such as plastics, pet food, and flour.

Regenerative Blowers

Regenerative blowers are driven by a rotating motor-powered impeller. The impeller is divided into small cells, and when it spins, trapped air is pushed outward and then guided back inside and into the next cell by specially shaped vanes. Each time air is accelerated in this spiral motion, it gains more pressure and eventually exits the blower.

This type of blower is crucial to many different industrial processes, such as:

  • Chip removal for engraving equipment 
  • Industrial drying
  • Medical devices
  • Slug removal in punching operations
  • Suction mounting for CNC machining
  • Surgical devices
  • Vacuum sealing for packaging applications

Centrifugal Blowers

Centrifugal blowers share some similarities with regenerative blowers. Both kinds use the spinning motion caused by a motor-powered impeller to pull air in, pressurize it, and push it out. But when it comes to centrifugal blowers, air is not recycled like it is with regenerative blowers; instead, it is flung out.

In centrifugal blowers, air enters through the middle of the impeller where it is spun, sped up, and forced out by centrifugal forces. The accelerated air exits while the center remains at a low pressure, and more air is pulled in.

These kinds of blowers are often used for:

  • Filtering and removing dust
  • Heating and ventilation
  • Industrial furnaces and incinerators
  • Pneumatic transfer

Determining What’s Best for You

Before you decide what type of blower is best for you, it is important to understand the advantages and disadvantages of each. 

PD blowers are able to provide a nearly constant air volume no matter the pressure conditions. They are efficient, carry greater operational flexibility, and have lower maintenance requirements. On the other hand, they can be noisy and have higher installation costs.

Regenerative blowers are quieter and more versatile. They require less maintenance as well and have a longer operating life. But they do carry some disadvantages, including the fact that they are not ideal for applications that require high pressure.

Centrifugal blowers are simple and cost-effective, making them a great solution for high-volume applications. However, they can also be sensitive to pressure fluctuations, can require more expensive maintenance, are noisier, and may have a shorter operating life.

Determining the necessary flow and pressure for your project can help you narrow down your search, as well as taking cost, maintenance, and noise factors into account. Further, your decision might depend on the industrial process for which you are seeking the blower. Once you pinpoint what is most important for your application, you can select the right one for you.

PD Blower Options at Northwest Flow Technologies 

At Northwest Flow Technologies, we offer PD blowers and blower packages with a wide range of models and features. We prioritize both quality and reliability in our products, which is exactly why we distribute the MD-Kinney brand of M-D Pneumatics® PD blowers. We are proud to distribute them in Alaska, Idaho, Oregon, Montana, and Washington. 

We also provide repair services for PD blowers and strive to provide quick turnaround times, high-quality workmanship, and honest prices as we work to help keep your facility up and running. We are here to support your success through innovative solutions.  For more information on our equipment and services or for questions about PD blowers, contact us today.

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