Equalizer Doctor™
The only doctor that changes blade angles, in seconds, during machine operation.
Features/Benefits
- Blade pressure applied through a liquid-filled tube assures precise blade-to-roll fit and equalized pressure
- Compact doctor design permits fitting in hard-to-access areas
- Longer blade life
- Cleaner roll surfaces
- Fewer breaks
- Enhanced sheet-shedding
Operational Efficiency
Allows for blade angle changes in seconds, eliminating machine downtime
Better doctoring control and accuracy due to precise angle-setting capability and equalized blade loading
Exceptional blade-to-roll fit eliminates roll wraps, improves sheet-shedding, contributes to longer blade life
Reduced maintenance due to a minimum of moving parts
Low energy requirements; primarily hydraulically and pneumatically actuated
A Revolutionary Breakthrough in Doctoring Design
Kadant Web Systems' unique Equalizer Doctor® assembly brings new levels of accuracy and control to doctoring operations. It actually lets you change blade angles up to 3° while the paper machine is in operation, and in only seconds. The result is an extremely precise blade-to-roll fit, bringing such benefits as improved sheet-shedding, elimination of roll wraps, and extended blade life. The Equalizer Doctor's remarkable angle-changing capability is due to two tubes: an air-filled seal tube and a liquid-filled equalizing tube, both located within the blade holder. The air-filled tube keeps dirt out of the holder, while also maintaining it in a semi-rigid position when the doctor is unloaded from the roll. It also prevents "jack-knifing" when the blade is loaded or unloaded.
The liquid-filled equalizing tube permits quick, on-line changes in blade angle. When the volume liquid in the equalizing tube is adjusted, its diameter changes, altering the angle of the blade. A larger diameter increases the angle, and vice versa. Increasing or decreasing the volume of liquid while paper machine is running takes only seconds at control system located on the mill floor. Air cylinders attached either to the assembly or to the doctor back provide fast, accurate blade loading by continually rotating the doctor to the achieve the desired PLI blade loading.
The loading pressure is transmitted through the liquid-filled equalizing tube which conforms to the roll crown and assures equal pressure across the roll. Since the Equalizer Doctor assembly can mounted at any angle or position, it is a superior choice for applications where doctors are hard access. It is also an ideal solution when reducing doctor-related downtime is a concern, and when doctor precision is vital to the quality of the end product. Its compact size also makes it easy to retrofit to most applications where standard doctors are currently used.
Maintenance on the Equalizer Doctor is low, with a minimum of moving parts to be maintained or replaced, and components are made of rugged, corrosion-resistant materials for long system life.
Construction
With its unique blade angle-changing capability and compact design, the Equalizer Doctor assembly will give superior performance in standard as well as difficult-to-access doctoring positions. Design features include:
- Rugged, corrosion-resistant stainless steel construction
- Air cylinders continually rotate doctor to roll for fast accurate blade loading
- Air-filled seal tube keeps holder free of foreign matter, and maintains it in a semi-rigid position when doctor is unloaded from roll
- Volume of liquid in liquid-filled tube is easily changed from a control panel on the mill floor, resulting in instant blade angle changes without downtime
- Blade loading is accomplished by air cylinders rotating the doctor back to the roll. This allows for better distribution of sheet-shedding impact through the total mass of the doctor back