Couch Roll Double Doctor

 

Dedicated double doctor effectively removes surface water and debris build-up on the couch roll.

 

Features/Benefits

  • Fewer streaks
  • Fewer paper breaks
  • Fewer holes
  • Fewer cracked edges
  • Reduced moisture to the press nip
  • Improved couch efficiency
  • Reduced maintenance
  • Uniform moisture profile
  • Increased vacuum box life
  • Reduced maintenance

 

Proven Results

  • Reduces water streaks by 50%
  • Reduces paper breaks by 50%
  • Removes surface water and build-up of fines and fillers
  • Vacuum-effect extracts debris from couch roll holes

 

An Innovative Solution to an Age-Old Problem

Traditionally used rubber wipes, used to remove water from the couch roll after the nip, does not always remove all the surface water, which leaves a seal or surface tension on the couch roll surface, trapping the fines and fillers in the holes of the roll. Kadant Solutions' engineering team approached this age-old problem from a new perspective, and developed the couch roll double doctor providing a two-phased approach. First, it removes the initial layer of surface water, creating a vacuum on the underside of the blade. This vacuum extracts the debris and fillers from the couch roll holes, bringing them to the surface. The second doctor then removes the remaining surface water, fines and fillers, sending a clean roll back to the nip.

 

It takes Two Doctors to Effectively Clean the Roll

The couch roll double doctor is a system that uses a DST doctor in both the first and second position. It is designed to fit within the confines of any couch roll, including arrangements where the wire returns under the roll. The DST doctors provide precise blade-to-roll fit using pneumatic pressure. The conforming of the blade to the roll effectively removes the majority of surface water in the first doctor position and cleans the fines, fillers, and remaining surface water in the second position. The support for the primary doctor is designed to allow the fines, fillers, and surface water, which are removed by the second blade, to pass through the doctor back and travel down into the save-all pan. The DST doctors can be independently adjusted for correct blade contact which, in conjunction with the ability of the doctors to conform to varying roll conditions, leads to increased blade life and reduced downtime for blade changes. With both doctors, loading pressure is adjusted through pressure-regulating valves in an independent control station.

 

For more information on couch roll double doctors, request product information using the link above.