Retrofitting project at Ahlstrom-Munkskjö
As a leading supplier of fiber-based materials, Ahlstrom-Munksjö depends on a smooth production process. For a retrofitting project to upgrade an existing paper machine in 2018, they chose the retro-fitting specialists at airinotec. And with excellent results: their rates of energy consumption and noise emissions have been reduced and their production conditions have been improved.
Ahlstrom-Munkskjö modernizes its production
With 45 production sites, Ahlstrom-Munksjö is the world’s leading manufacturer of fiber-based materials. At its site in Aalen-Unterkochen, Germany, Ahlstrom-Munksjö produces some 76,000 tons of decor paper per year for the furniture and laminate flooring industry using two paper machines. In 2018, Ahlstrom-Munksjö decided to have the dryer hood on its PM3 paper machine overhauled. At the same time, it wanted to keep its production losses as low as possible.
The goal: higher rates of energy efficiency and better production conditions
The subject of the retrofitting was paper machine PM3 with a production capacity of 8 t/h with a working width of 3 m. Ahlstrom-Munksjö had a number of objectives: to save energy, to achieve improvements in the climate-related production conditions in the production hall and sound insulation for noise emissions to the outside. The installation of a new automation and measurement data acquisition system was also required, and the implementation of a dew point control system for the pre-dryer and after-dryer sections to record the changing production conditions was planned.
Decent planning ensures safe implementation during downtime
To keep the impact on production as low as possible, the detailed advance planning of a project of this kind is of elementary importance. This is where airinotec benefits from its many years of experience in complex projects: the measurement of the machines, the sequential planning, the determination of the new components – all the necessary process steps were carefully carried out. Finally, the pre-assembly took place during the ongoing production. The downtime assembly was then completed at the turn of 2018/2019.
The scope of supply included an air-to-air heat recovery system, a speed-controlled exhaust fan, the replacement of the hood panels for the paper machine and a silencer with retractable baffles for the cleaning. The process air supply system remained in place, but was combined with the new heat recovery system. A Siemens SPS including a touch panel was implemented for the automation. The required dew point controls for VTP and NTP were implemented using sensors and actuators, which were equipped with automatic cleaning modules. After the conversion and commissioning, the production started as planned.
“We knew that we had a time frame of one week in which the paper machine was shut down,” explains Kevin Mey, the Distribution Engineer in charge of paper at airinotec. “To get everything done in that time frame, planning is of key importance, and everything went smoothly during this project. We have demonstrated our expertise as a retrofitting specialist – and also shown that an optimum solution doesn’t always have to mean a completely new system.”
The result: an optimized paper machine
The expectations of Ahlstrom-Munksjö regarding the project were met throughout. The customer was particularly impressed by the precise planning: by adhering to the schedule, any disruptions to the workflow were kept to the minimum. During ongoing operations, the conversion has further advantages: steam is no longer required for heating the process ventilation, which has significantly reduced the energy costs. And the quality of the working environment has also been improved: the noticeable reduction of hot, humid air entering the PM hall has improved the climate in the production hall and provided the basis for further optimizations. In addition, the lower noise emissions to the outside have improved the noise protection situation at the production site.
