A large piece of saltcake falling from the ceiling is believed to be the cause of a failure of a recovery boiler last Saturday at the Northwood Pulp Mill.
Mill manager Robert Dufresne said Friday that further investigation is still needed, but it appears the saltcake was large enough to damage three to four screen tubes on the boiler, which in turn pressurized the boiler and tripped it.
But the trouble did not end there.
"We had more of that water bubbling and knocked more saltcake from the ceiling and damaged other tubes," Dufresne said.
Saltcake (anhydrous sodium sulfate) is used in the wood pulp process.
About 60 employees were evacuated for about two hours last Saturday evening.
No one was injured but it's expected the boiler will remain out of commission for a further two to three weeks for repairs.
"A large number of screen tubes will have to be changed," Dufresne said.
The damage will cut the mill's production by 25,000 tonnes but customers won't be affected.
"To mitigate the impact of the incident, management intends to continue operation of the second
production line at the mill and will advance certain mill maintenance activities previously
scheduled to be performed during a planned mill shutdown in September," company officials said in a press release Friday.
"Production at the Partnership's Intercontinental Pulp Mill and Prince George Pulp and Paper Mill is not affected by the curtailment at Northwood."
The boiler went through a $107.2-million upgrade last year as one of four projects for which Canfor Pulp received $122 million from the federal government through its green transformation fund, after putting in a further $33 million of its own money. It had been running without trouble for about six months.
