Steam plant work paying off for UI

MOSCOW – Modifications that made a wood-fired boiler more efficient saved the University of Idaho up to $10,000 per day during December’s cold snap, officials said.

Scott Smith, the steam plant’s foreman, said the modifications allowed the boiler to produce more steam to heat campus buildings and water.

He said the amount of steam has been increased by 50 percent, making a big difference at a school that uses steam for about 80 percent of its heating needs during the winter.

“They tore that boiler down to its absolute bones,” said Joe Kline, the director of engineering and utilities at the school. “They didn’t have to push that hard. They just said, ‘We can do better.’ ”

Kline said that although the boiler burns more wood in producing more steam, it’s still cheaper than gas-fired boilers.

“It’s really a big deal when you talk about the difference between burning wood and burning gas,” he said.

Smith said the boiler burns wood chips, and it gets its supply from lumber mills in the area.

“Anything they can’t use as a product, their waste, becomes our fuel,” Smith said.

The modifications to the boiler involved the grates that move chips through the boiler’s firebox, where temperatures reach 3,000 degrees.

The grates were redesigned and then cast in a more durable alloy by Hern Iron Works in Coeur d’Alene and Wear-Tek in Spokane.

To put in the grates, the boiler had to be taken apart.

“I was a little concerned, to be honest,” Kline said.

“We had it out in the parking lot,” said Smith. “We had pieces everywhere.”

Only nine of the 15 rows of grates were replaced, Smith said, because of the cost. But he said that means the boiler has the potential to become even more efficient if the other grates are replaced.

“We can’t afford to replace them all at once,” he said.