February 20, 2012

Concrete plays a big part in mill's new generating station

HARMAC PACIFIC

The hog fuel handling upgrade project is currently underway at the Harmac Mill in Nanaimo, British Columbia. A new generating unit will also be built to produce electricity from the hog fuel.

SHANNON MONEO

correspondent

As Nanaimo Forest Products installs its new turbo-generation unit over the next 18 months, the $45 million electricity-producing project will be pouring on the concrete.

About 85 full-time-equivalent jobs at the Harmac Pacific mill site will be created during the project, which will result in the production of 25 megawatts of electricity.

Ten of those megawatts will be added to the existing 30 megawatts already produced at Harmac (by a turbine installed in the 1960s) while the remaining 15 megawatts - enough to power 17,000 homes each year - will be sold to B.C. Hydro under a 15-year agreement.

“It’s an enormous project for us,” said Levi Sampson, Nanaimo Forest Products president. “And yes, we’ll be using a lot of concrete.”

While the amount used for this mechanical installation won’t be comparable to amount used in a bridge, a substantial amount of the building material is necessary, said the company’s engineering superintendent, Ryan Prontack, who is also the project manager.

He has already spent two years working on the venture, which he considers the Holy Grail of mechanical engineering projects.

So many elements, such as steam, piping and ancillary equipment, come into play.

To house the heart of the project, the axial turbine, a new steel building with a metal roof and large concrete foundation will be built.

A concrete supplier hasn’t yet been determined for that part of the project. Tenders were released in January, Prontack said.

What’s known is that the turbine will be imported from either France or England.

The company looked for North American manufacturers, but they don’t exist, Prontack noted.

When the turbine arrives, it will sit on a large concrete pedestal measuring 16 feet by 40 feet by 10 feet high.

Roughly 6,400 cubic feet of concrete (240 yards) will be poured, Prontack said.

That heft is necessary because the turbine, rotating at 5,200 rpms, non-stop, 365 days of the year, is not only large and heavy, but it can vibrate.

“We need the large mass to dampen any vibration,” Prontack said of concrete’s strength under pressure.

HARMAC PACIFIC

Concrete will also be used for the foundation for the steam condenser.

A significant part of this project is upgrading the pulp mill’s infrastructure used to unload the barged-in hog fuel sourced from across B.C., Prontack said.

It’s that hog fuel that will be burned to produce steam that travels through the turbine, gets condensed then powers the generator which makes the end product of electricity.

To ensure enough hog fuel is on hand to power the turbine, a new $4.5 million conveyor system and storage towers, similar to the existing set-up, have been under construction since November.

By March, two new eight-foot-diameter, 100-foot tall concrete storage towers will be operational, ensuring that the power boiler, which can handle energy produced by up to 450,000 pounds of hog fuel per hour, stays fed.

It’s been more than three years since the Harmac mill was bought by a consortium of investors which included the Sampson Group and Harmac workers.

Today, the once-bankrupt pulp mill employs just more than 300 people, Sampson said.

He said the deal with BC Hydro gives Nanaimo Forest Products another revenue stream.

“We can now ride out the bottoms in the market,” Sampson said about the ups and downs that define B.C.’s forest industry.

And wood waste that would normally be sitting somewhere, decomposing, is being burned to produce electricity.

Sampson noted that concerns about increased particulate levels, because of more burning, won’t materialize because of the high level of screening used at the mill.

Currently, five mg of particulate per cubic metre are released into the air at Harmac’s site in Nanaimo.

The maximum allowed by B.C.’s Ministry of Environment is 230 mg per cubic metre, Sampson said.

With a facility that already treats its wastewater and creates electricity, in effect quasi-utilities, Sampson hinted that more cash-generating initiatives may follow the deal with BC Hydro.

HARMAC PACIFIC

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