UW-Oshkosh engineering professor earns patent for flameless industrial oven

Prototype of the flameless impingement oven built by Pawel Olszewski stands next to a prototype of the flameless impingement oven he built in the engineering and engineering technology department. The oven mixes air and flammable gas in such a way that it creates heat without visible flame.
Prototype of the flameless impingement oven built by Pawel Olszewski stands next to a prototype of the flameless impingement oven he built in the engineering and engineering technology department. The oven mixes air and flammable gas in such a way that it creates heat without visible flame.

Call it a hot new invention.

Pawel Olszewski, a University of Wisconsin-Oshkosh associate mechanical engineering technology professor, recently was granted a U.S. patent for his flameless impingement oven, designed and built in the Teaching and Energy Research Industrial Lab (TERIL) on the Oshkosh campus.

“I’m so happy,” said Olszewski, who began the patent process back in 2019 and received the news of approval in February.

Industrial ovens — like the ones this creation improves upon — are used for a variety of purposes, including heat treating and melting materials like steel or aluminum. The benefits of the flameless impingement setup, Olszewski said, include faster heating to increase productivity, fewer emitted pollutants because thorough heating reduces nitrogen oxides and a reduction in fuel consumption with gases exhausted at lower temperatures.

The new oven arranges natural gas and air jets to directly affect the object being heated, substantially transferring heat by impingement transfer rather than by conventional radiation and thermally induced convection.

RELATED: Oshkosh Boys and Girls Club's $18M renovation is in its second phase. Here's what will be done this year

RELATED: One Ukrainian teacher faced an odyssey after fleeing the invasion. She wound up in Oshkosh, teaching about the conflict.

Because the air and gas are swirling at such speeds inside the oven — “like a huge tornado,” Olszewski explained — the chemical reaction to produce extreme heat is occurring everywhere all the time.

The chamber, which is a foot tall, a foot wide and a foot deep, reaches temperatures beyond 1,800 degrees Fahrenheit.

“Everything mixes and the gas is always meeting the oxidizer,” he said. “So when you look inside the furnace during the normal operation, there are no flames. You have combustion but no flames. Natural gas oxidizes; it reacts with the oxygen (and) generates heat, but there is no flame.”

The prototype was built in the TERIL on the third floor of the Halsey Science Center. The oven is the fourth unique industrial system built there and requires the other three to run: chilling, pumping and compressed air.

SUPPORT LOCAL JOURNALISM: Our subscribers make this coverage possible. Click to see The Northwestern's special offers at thenorthwestern.com/subscribe and download our app on the App Store or Google Play.

The idea can be traced back to when Olszewski was a post-doctorate fellow at the University of Michigan, where he worked with simpler flameless ovens. The ideas continued to swirl around in his mind and when he came to UW-Oshkosh in 2014, he and his students began to create all the industrial systems that allowed for the oven to exist.

“There is no single piece of the equipment that was purchased in the state it’s in. Everything was purchased as a component,” he said. “We cut the frames, we organized our own control cabinets, everything here including the software that controls all of the systems.”

It was June 2020 when the “Eureka!” moment happened and the oven worked without any sight of a flame. WySys, a Madison-based nonprofit dedicated to helping investors protect their intellectual property, had already submitted the patent application. Olszewski was confident enough in his research and experience that he knew his design would work, even if he hadn’t seen it for himself.

Pawel Olszewski points to a diagram of flameless impingement oven, which mixes air and flammable gas in such a way that it creates heat without visible flame.
Pawel Olszewski points to a diagram of flameless impingement oven, which mixes air and flammable gas in such a way that it creates heat without visible flame.

What Olszewski is hoping for next is a local company to express interest so the idea can grow beyond the single prototype. He said any company that melts aluminum, cast iron, steel or even glass could make use of the technology. It can translate to more or less any size, and ovens already in use could be retrofitted.

“I’m hoping it will catch somewhere,” he said.

Shane Nyman is a content specialist for UW-Oshkosh. This story originally appeared on uwosh.edu/today and is reprinted with permission from UW-Oshkosh.

This article originally appeared on Oshkosh Northwestern: UW-Oshkosh professor earns patent for flameless industrial oven