Suspended 12 feet in the air of the Black Engineering Building is a room where ISU researchers are studying the interaction of solids, liquids and gases in a closed system.

In the end, they hope to find a better way to not only make recycled paper, but also refine oil and make beer.

The room is lined with nine tons of lead, so researchers can view X-ray images without being exposed to harmful radiation.

The new X-ray visualization facility was designed and built by a team of three ISU researchers in an effort to study this interaction, called multiphase flows.

Specifically, they are studying the process of ink removal from paper, a multiphase process used in paper recycling.

“This is surely a unique instrument,” said Terry Jensen, scientist at the Center for Nondestructive Evaluation.

“With all of its unique features, there’s no other instrument like it in the world.”

In the box, researchers can study the way a gas moves through a medium — an important thing to know because it determines how well a product like recycled paper turns out, said Ted Heindel, associate professor of mechanical engineering.

“We visualize the separation process of the gas moving through a fiber suspension,” Heindel said.

The X-ray visualization facility can record the actual process of a multiphase flow, rather than relying on computational models for prediction. The device allows the researchers to actually see the process.

“Basically, it’s a real-time X-ray detector,” said Joe Gray, adjunct associate professor for the Center for Nondestructive Evaluation.

Other X-ray imaging devices, like the ones used by dentists, aren’t able to capture clear images from something that’s moving.

“This detector can generate images at 20 frames a second,” Gray said.

The X-ray facility works by capturing 3-D images of a multiphase flow, which can be put together in a computer or made into a 3-D movie for study.

X-rays of the multiphase processes are taken from a 15-foot-tall column, which is more than a foot in diameter and is on a lift, so it can be moved up and down.

“What happens at the bottom of the column, the top of the column and the middle of the column is different,” Gray said.

“We want to be able to study the column at different regions in the tube.”

The lead-lined room allows researchers to track the trajectory of bubbles in a column. When paper pulp is loaded into a column during recycling, large bubbles form and help control the chemical reaction.

“We call it our lead tree house,” Gray said. “It’s like a small office.”

The X-ray visualization facility could lead to better control of the flow process.

Because the facility allows researchers to see what is happening during a separation process, the process can be made more efficient, and recycled paper can be made of a higher quality.

“Hopefully in the long run that will lead to better control of these chemical processes and lead to more efficient operation of these different processes, with paper recycling being just one example,” Jensen said.

“This is a system that can be used to study the fundamental dynamics of a number of these types of multiphase slow processes.”

Other industries use the same type of multiphase flow process for oil refining and food processing, he said.

“There are several industries that have multiphase flows,” Heindel said.

“Anything from making beer to paper recycling to making food to harvesting corn.”

These industries could also benefit from the new technology.

“If you understand the process to the point where you can predict what it is, then you can start to design an optimal process,” Gray said.

“By getting this kind of information, you can understand and develop the correct kind of model.”

The X-ray visualization facility was designed and constructed with the help of $640,000 from the National Science Foundation and ISU organizations, including the College of Engineering, the Institute for Physical Research and Technology, the Department of Mechanical Engineering, and the Vice Provost for Research, Heindel said.