By Hugh O'Brian
To get the highest productivity out of the equipment, Longfeng made the decision to install numerous state-of-the-art automation systems on the Metso paper machine. Thus the machine is one of the most highly automated in China, with Metso's automation group supplying the metsoDNA process and machine controls, Sensodec condition monitoring, video break analysis, PaperIQ quality control system with IQDilutionPro and IQSteamPro profilers and kajaaniWEM and kajaaniRM3 wet end analyzers.
Designed for results
Zhao Jiuhui, Longfeng's vice general manager of production, explains the ideas behind the automation solutions. "This is a new company with many on the machine crew new to the paper industry, having no real experience in papermaking. Therefore, we installed almost everything that was available in terms of automation from Metso and this has turned out to be a very good decision. This highly automated paper machine is easy to run and we have used the automation solutions to our full benefit.
"We get high machine production efficiency of 93% by using full automatic control. We also see positive benefits such as excellent runnability and stability, very high quality and low raw material inputs of fiber and energy."
Results with steam profiling
As one of numerous examples of how automation solutions have benefited Longfeng, Zhao cites the IQSteamPro steam box after the second press. "The steam profiler has given us real results and we are using it full time. We get a big improvement in dryness of 2 to 3%, meaning 52-53% dryness, versus about 49-50% when it is not in use. This saves us enormous amounts of steam, maybe 5-7% total in the dryers.
"In addition the IQSteamPro gives us a very flat dryness profile, with a 2-sigma of less than 0.2 % or even as low as 0.15 % sometimes. This is extremely good," he adds.
"We also get fewer dryer breaks due to the higher dryness going into the dryers, which is a big advantage since machine breaks are so costly. So we are very happy with the steam profiler due to all the important benefits it gives us."
Stable wet end helps productivity
Another example mentioned by Zhao of the results Longfeng gets with automation is the kajaaniRM3 retention and whitewater control system. "By keeping the white water consistency at a stable level, through automatic adjustment of the retention aid flow, the entire wet-end operation is more stable. Therefore the whole machine is more stable, leading to direct benefits such as better productivity, more uniform paper quality, fewer web breaks, higher machine speeds and quicker grade changes."
Zhao also says that the DNAforesight web break inspection is great tool as well. "The operators use the video to see exactly where the break occurs and they can learn from it, to help avoid it next time."
The cooperation with Metso has been very good, Zhao explains. "Metso is not only very professional but they have also become good friends who we can call with any problem at any time and know we will get solutions. I think the fact that Metso is so specialized in both paper machines and papermaking automation is extremely beneficial. Other automation suppliers have very good technology but we feel that the Metso depth of papermaking knowledge is something that gives us a big advantage."
Zhang Shugang, Longfeng Paper's automation manager, agrees with Zhao that Metso's support has been critical to their success. "When we started up PM 1 you could feel the strong engineering, startup and operational skills that Metso has brought to us. They got the machine commissioned very rapidly and gave us very helpful insight and suggestions to make the operation run smoothly after they left. We also appreciate the fast and efficient local service when we do have questions. We feel the local service as a real plus.
"We now have everything on automatic and are very pleased with it," continues Zhang. "Of course when we started the machine we needed to smooth out the fluctuations as we trimmed in the automatic control systems but we have learned from that and now it is all running smoothly. This is important as many of our crew are new to papermaking. They are learning the right way of doing things from the beginning and learning well!"
Zhao concludes that "by using automation to its fullest, we get better quality and higher process efficiency with less work and headaches." It's certainly hard to argue with that.
Hugh O'Brian is paper engineer who has been covering the pulp and paper industry as a journalist for more than 20 years.
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