Refiners are running at double design capacity, case study

Asia Pulp & Paper (APP) Guangxi Jingui Pulp & Paper Co., Ltd., one of the largest mechanical pulp producers in the world, is located in the province of Guangxi in southern China, close to the Vietnamese border. The mill employs more than 3,000 people.

In 2013, pulp production reached 550,000 tonnes. At that time, APP decided to install a new BCTMP (bleached chemi-thermo-mechanical pulp) line at its Guangxi Jingui pulp and paper mill, and turned to Valmet for assistance. The new line consists of two Valmet RGP 82 CD high-consistency refiners in the chip refining stage. Subsequent refining is carried out in three Valmet RF-5 conical low-consistency refiners.

Since its start-up in mid-2013, the capacity of the line's refiners and the lifetimes of their segments have reached remarkably high levels, and their energy consumption has been low. The mill currently produces 600,000 tonnes of top-grade board annually. APP's investment in Valmet Refiner Segments, Shive clean supports its ambitious long-term sustainability roadmap, Vision 2020.

Refiners running at almost double design capacity

The design capacity of the pulp line is 750 TPD (tonnes per day). As the line consists of two parallel chip refiner units, this means that each refiner is guaranteed to run at a production rate of 375 TPD. APP Guangxi Jingui is determined to take full advantage of the pulp line though, so they have pushed the equipment to the limit and run over 700 TPD through just one machine – almost double the design capacity – with no deviations in final pulp freeness.

Long segment lifetime

The performance of the refiner segments has been very good. APP Guangxi Jingui has been running turbine segments with Valmet Refiner Segments, Shive clean feature – Valmet's latest segment patterns – right from the very beginning. These segments are specifically designed for hardwood BCTMP processes; they target pulp quality as much as they focus on minimizing energy consumption.

The operating principle of Valmet Refiner Segments, Shive clean is to let the flow of steam move forward in grooves while the fiber flow is forced up to the bars for further development.

These segment patterns are helping APP Guangxi Jingui achieve the longest segment lifetime in China: more than 3,000 hours on several occasions, with a record of 3,200 hours. The mill's Production Manager, Yichang Zhong, is happy with the input of the Valmet segment team, and he believes that continuing cooperation will mean they can achieve even better performance.

"The best BCTMP mill in China"

Yichang Zhong was also happy to say that APP has the best BCTMP mill in China. Two important factors have contributed to the high level of customer satisfaction at APP Guangxi Jingui: the stable operation and the excellent availability of the line, which are the natural outcome of choosing turbine segments featuring Valmet Refiner Segments, Shive clean.

The revolutionary new way that the new segment pattern handles steam also ensures that refiner power and disc gap variation is minimized. This is very important when the goal is long segment lifetime, as it is at APP Guangxi Jingui.

For more information on Valmet Refiner Segments, Shive clean and how Valmet can help your mill reach its refining goals, contact your Valmet representative.