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Continuous press felt cleaning
Press felts degrade continuously during their lifetime. The standard
solution to solve this problem is to use low-pressure water spray.
Low-pressure water sprays are however not capable of cleaning the
press felts adequately. An attempt to solve this problem has been to
use high-pressure water sprays, but these tend to wear out the press
felts too fast if used more than 15 to 30 minutes an 8-hour shift. A
solution with rotating traversing high-pressure nozzle is tested and
used nowadays.
The solution provided by Ultra Technology gives a continuous cleaning
of the entire press felt without wearing them out, but on the contrary
increasing their lifetime. Using the continuous ultrasonic cleaning
also gives higher paper dryness after press section throughout the
full press felt lifetime. The degradation of the press felt function
is shown to be small for the full lifetime, in comparison to a quite
large degradation for a conventionally cleaned press felt. Compared to
the high pressure water solution, the major advantage for the
ultrasonic cleaning is that it cleans the full press felt width all
the time, while the rotating traversing solution only cleans 0,1 to
2,5 percent of the press felt width at a time. |
