Pulp Paper & Logistics
ANDRITZ 19
Two new-generation HQ-Press bark presses at wood processing increase energy value of bark Over the course of the Helios
per cent accurate, as there was only a 15mm clearance for the expanded boiler to fit in.” SCA project manager Wänglund
There were five start-ups in the white liquor plant during project Helios
project case it is extra special, as we are taking additional heat from recovery boiler exhaust and producing additional low pressure steam, which is used in the pulp dryer – this saves the fresh steam and has never been done before.” The recovery boiler expansion
was something of a project on its own. Grönqvist explains: “This was really new thinking, to expand capacity of the recovery boiler from 3,300 to 5,000 tds/d, and meant a lot of design and on-site engineering work. During the shutdown, we had to move a hanging wall (over 70 metres high and weighing 460 tonnes) 3.8 metres to house the expanded boiler. This exercise had to be 100
says, “The recovery boiler expansion was really special, and something that had never been done before, so there was a lot of excitement around the mill. There were close to 500 people working day and night while the wall was moved, so the atmosphere was very intense. In the end we were even more delighted, as initially the boiler capacity was going to be expanded to 4,400 tds/d, but during the pre-project we reached another figure of 5,000 tds/d which was extremely good for us.”
Ten perfectly-timed sequential start-ups The project to double capacity at SCA Östrand took nearly three years with numerous start-ups of combined equipment at carefully- timed phases to allow minimum disruption to the mill’s operation. In fact, there was only one complete shutdown during the whole project, when the recovery boiler expansion took place.
project, there were 10 separate Andritz start-ups, including five in the white liquor plant, two in the wood processing area, two in pulp drying and the recovery boiler start-up. The recovery boiler fired up on 23 June 2018 and full production of the complete Helios project began on 2 July. Ingela Ekebro sums up: “To build a new mill inside an ongoing operation has some challenges, of course, but there are also major advantages, particularly if you get the start-up sequences right when it comes to all the various processes and equipment. “We started up the wood
processing plant first, followed by the pulp dryer, which gave us a huge advantage to have these working before the main start-up up of the recovery boiler.” Wänglund adds: “The numerous sequential start-ups were an advantage, as they gave us a buffer and extra time to debug the system before the main start- up when full capacity would be expected.”
Grönqvist concludes: “Ten successful start-ups by Andritz while the mill was still running with no serious incidents or accidents is work well done. Without good cooperation with SCA and seamless teamwork within the Andritz team, this would never have been possible.” Wänglund continues: “It is, of
course, during this pre-study when we have lots of discussions with suppliers. While we know how to run a pulp mill, we obviously don’t have the experience of what is latest on the market, and what new technology we should be looking at to maximise the project’s success. This is where knowledge and the latest in technology and processing experience from ANDRITZ was vital.” Ekebro concludes: “The discussions with suppliers during the pre-project study were extremely important for us because that is when we set the framework for the design.” More information from Henrik Grönqvist. Email: henrik.
gronqvist@andritz.com
4 May/June 2019
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