Centrifugal Fan Functions for Industrial Dryer Applications

Industrial dryers like the rotary dryer and others remove moisture in the production process of various foods, chemicals, biofuels, and other products. The rotary dryer handles a wide range of materials with different sizes and levels of corrosion. It uses a large drum that rotates to dry the material with a direct combustion-heated gas stream.


The fans function as supply fans and exhaust fans for the industrial dryer. The supply fan pushes clean, ambient air through the combustion chamber as it flows into the rotating drum. The exhaust fan pulls the gas through the system to various other applications like cyclones, dust collectors, and scrubbers to address emissions for safety and compliance.

Our representatives with Lathrop Trotter frequently work with industrial rotary dryer applications, so we spoke with them to get some insights for you.

Lathrop Trotter Insights on Fans for Industrial Dryers

Lathrop Trotter, a division of Koch Air, represents AirPro Fan & Blower Company in Ohio, Indiana, and Kentucky. The firm’s extensive experience with boilers, power generation, and industrial and commercial HVAC means they’re also well-versed across industrial fan applications like industrial dryers.

Lathrop Trotter Sales Manager and AirPro representative T.J. Mueller outlined some of the key considerations and potential issues to address when designing fans for industrial dryers. Here are some highlights from our conversation with T.J.

Calculating the Drying Process

It can be very difficult to calculate how to dry something, because of varying levels of moisture that must be removed. It’s important to size the fan with at least a 15 percent margin to allow for the increased speeds that might be necessary to remove more moisture than anticipated without changing the class of the fan, which would be disruptive and costly after the fact.

Exhaust Fans for Industrial Dryers

Exhaust fans can be tricky in industrial dryers because of the high temperatures and particulate-laden gas stream. It can be tempting to use backward inclined or backward curved fans because of their efficiency, but the low pressure they create makes them prone to collecting material and creating an imbalance in the fan. Airflow monitors similarly get clogged, so some of the products that work in other applications really don’t work here. In general, we advise sticking with a radial tip fan for optimal efficiency and operations.

Supply Fans for Industrial Dryers

The supply fan in an industrial dryer application is less prone to issues because it is handling clean, ambient air. That means you can capitalize on the high efficiencies of backward inclined or backward curved fans.

The Bottom Line on Fans for Industrial Dryers

The variations in what the rotary dryer is processing mean a great deal of nuance in the fan specification process.

“The main thing we need to be able to count on with these industrial dryer fans is quality control. We don’t have to worry about that with AirPro. They’re just so good at that. You can see it in their nearly perfect warranty rate, and you can see it in each and every fan they deliver. They just don’t have the issues we might otherwise worry about.” -T.J. Mueller, Lathrop Trotter

Learn More About Fans for Industrial Dryers

You will find comprehensive information on our Dryer Application page.

We want to thank our rep partners at Lathrop Trotter for their contributions to our industrial dryer application overview. To learn more from them, visit their website or contact them at 513-655-6795.

If you have questions about industrial fans for dryers or any other application, call 715-365-3267 or contact us, and one of our engineers will connect with you.

Content Related to Industrial Dryer Applications

Here are related posts and case studies that might be of interest as you think about your application.

We’ll be highlighting several more of our applications and reps in the coming months. Keep your eye on the All Things Fans blog and sign up for our newsletter to stay up to date, and please join the conversation on LinkedIn.

Contact us for more information or for a connection with your local rep.