black liquor (kraft), red liquor (sulfite) and sodium liquor (for example, sodium-containing ef- fluents from the BCTMP process). “Our first sulfite boilers were installed in the 1950s,” explained Bernd Zuschin, Andritz Project Manager, “so we have a long history and deep experience. We have continued to develop this technology and this is certainly recognised by our customers. For example, this is the first ammo- nium sulfite boiler we have ever built. Our deliveries up to this point have been for magnesium- based sulfite processes. We also delivered the world’s largest sulfite boiler and chemical recovery unit to Sappi Saiccor in South Africa, started up in 2008.”

According to Dottori, “We were looking for a highly flex- ible boiler to deal with the steam consumption swings at this site and not have our utilities constrain our pulp production processes. Andritz’s track record convinced us that they were the best supplier for this project. We were especially impressed with their capabilities in handling different and difficult fuels – even municipal solid waste, refuse-derived fuels and various cooking liquors. We have two of

their units at our sister mill in Tar- tas, France, which gave us a good reference”.

The new boiler replaced three operating boilers and one boiler that had been shut down. As Cousineau explained, “Our three old recovery boilers were what I like to call ‘liquor incinerators’ since they were converted coal- fired boilers operating at low pres- sures and temperatures. They had reached the end of their useful life. Fouling was one of the big- gest problems. This led to corro- sion issues and made maintenance more intensive.”

Tembec began talks with the then Austrian Energy & Environ- ment (now Andritz) in 2010 and sent out tenders the following year. “We began to talk in detail in 2011 and provided some budg- et estimates and calculations,” added Zuschin. “We signed the contract with Tembec in March, 2012.”

Andritz delivered all the boiler components to the site by mid- 2013. “This was a relatively fast-track for delivery, especially considering the sea transports from Europe to Canada, but we made all of the milestones,” said Christoph Gruber, Andritz Com-

Left to right: Michel Monet, Tembec; Paolo Dottori, Tembec; Bernd Zuschin, Andritz; and Paul Cousineau, Tembec, in front of the new SulfitePower boiler.

missioning Manager. The boiler was started up early in 2015.

Simplified operations Life for Tembec’s boiler opera- tors is now simplified. “We now run two boilers – a high-pressure bark boiler, which had a small 8 MW turbine, and the new Andritz boiler,” confirmed Trevor Turner, Head Operator. “With this project, we shut down the small turbine since it was only back-pressure and now have all the steam flow-

ing through one high-efficiency turbine with a condensing unit.” Fouling is considerably reduced with the Andritz boiler. Accord- ing to Michel Monet, Steam Plant Superintendent, the arrangement of the heat transfer surfaces in the SulfitePower boiler allows his operators to optimise tempera- tures in specific zones to reduce fouling and potential corrosion. “This, coupled with the horizontal configuration of the economizer and superheater, will hopefully


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