In beginning of 2000, Steyrermhl AG, Austria, now a member of the UPM-Kymmene Group, started a project to build a two-line deinked stock preparation facility, with a total capacity of 750 tpd. Some months later after a lot of checking and negotiations, BTG was selected to supply the consistency and brightness transmitters in the system.
The challenge to high-quality
Todays high demands on paper quality require secondary fiber material that is as good as possible, good machinery, reliable and precise field instruments, proven DCS systems and an advanced process control strategy. Since the deinking process is carried out in a minimum number of chests, the reliability of field instruments has become more important. Automated start-up and shutdown procedures as well as production control programs enable rapid and easy control of the process.
MEK-2300 meets consistency demands
For this reason, Steyrermhl AG measures consistency with wellproven MEK-2300 technology from BTG. The ten units installed on the two DIP lines run at an accuracy level that compares very favorably with laboratory samples. The bone-dry production rate calculation is based on consistency and flow rate. Therefore a precise consistency transmitter is one of the most important instruments in the deinking process. "Also due to the easy handling of the transmitters, a quick start-up and early availability was possible. Within very short time and with just a few laboratory checks, good accuracy was achieved. The final optimization and fine tuning to achieve a stable process is now in progress," say Steyrermhl staff.
BT-5300 brightness transmitters
When using recycled paper as the raw material to produce paper, brightness can be influenced in many different stages in the process. In order to be able to monitor and control the success and efficiency of the processes in the deinking stages, the feed and accept brightness of the individual stages are continuously measured. BTG BT-5300 brightness transmitters were installed at Steyrermhl on the DIP 4 line at the inlet of Flotation Stage 1 and at the inlet and outlet of peroxide bleaching as well as in the finished stock. This means the operators can reliably monitor the operations of any individual subsystem at any time, and respond accordingly. This makes it possible to keep bleaching at an optimum level without overdosing to keep chemical costs at a minimum level. The DIP 3 line is currently being rebuilt and extended to produce deinked pulp for SC papers. BT-5300 brightness transmitters are to be installed at the various process stages as well.
The MEK-2300 and the BT-5300 belong to the BTG Smart family of transmitters, which means that one easy-to-use hand-held terminal configures each transmitter. The portable terminal can be pre-programmed at a convenient location and then downloaded to a transmitter. All adjustments are made from the terminal keypad using menus for specific configuration functions. The makes the programs easy to operate, user-friendly and self-instructing.
The operating results of the deinking plant for PM 4 at Steyrermhl speak for themselves. Also due to easy instrument handling and reliable values from the very beginning, the start-up was very successful. "The process is basically controlled by consistency and flow. The brightness values from the BT-5300 give us important information about the changes in the peroxide bleaching behavior," says
Mr. Klaus Gabler, the Deinking Production Assistant at Steyrermhl. "We made a good choice when we installed MEK-2300 Consistency transmitters and the BT-5300 Brightness transmitters from BTG," he adds.