Doctor Blades and Variations
Doctor blades are often used to scrape web from a roller or prevent the buildup of contaminants on roller. Generally these doctor blades are oscillated in the transverse direction across the face of the roller just after the outgoing web leaves the roller.
We often see that the doctor blade pressure creates a considerable drag on the drive for the roller. In many cases on paper machine dryer cans, the doctor blade can use up 100 HP on a dryer with a 500 HP motor. This is easy to prove by monitoring the motor load while relieving the doctor blade pressure or removing it entirely.
Secondly, the load created by the doctor blade can often vary with the period of the oscillation.
A steady load created by the doctor blade merely wastes energy every hour the doctor blade is applied. A load variation caused by the doctor will also result in small speed variations which may result in large tension variations.
Moral – used the lightest doctor pressure and change blades when wear becomes uneven.
Spécialiste Opérations Machines chez Cascades CS+
3 年Agreed and thanks again Clarence. I would add: perform regular maintenance as part of your preventive maintenance program on the doctor holders, adjust angle, etc. To get maximum cleaning performance at lowest energy consumption.