A system for preventative maintenance
At the Stora Enso paper mill in Hylte, an unplanned production stoppage costs about SEK 70,000 an hour. In order to avoid an encoder causing such stoppages, Leine & Linde has developed an advanced diagnostic system, ADS™.
The 8.4 metre-wide paper rolls that are then cut down into the required widths and supplied to printers and newspaper publishers
Deep in the woods of the southern Swedish region of Småland, a paper mill was established as early as 1907. Paper for newsprint has been produced here since 1972, and there are currently four paper machines in production, operating in three shifts.
"The paper machines can produce paper at a rate of up to 1,550 metres per minute with a width of 8.4 metres," explains Ulf Ahlstrand, technical engineer at Stora Enso. "We use pulse encoders primarily to obtain feedback on the speed of the rollers in the paper machines. An unplanned production stoppage is, as I have said, extremely costly and so we make very high demands in terms of the reliability of the encoders."
In order to meet the requirements for a high level of reliability, Leine & Linde has developed an advanced diagnostic system, ADS™, for the incremental encoders in the robust 800 series. The system is based on a rapid logic in conjunction with a microprocessor continuously monitoring all the encoder's functions and it is therefore able to detect faults at a very early stage. This occurs early enough for the encoder to fulfil its function, so that the encoder can be changed during a planned maintenance stoppage instead of causing an unplanned stoppage.
For further information about encoders used in this industry, contact Håkan Karlsson on +46 (0)152-265 51
