Broke related problems
1. Excess dilution in couch pit, especially when only trim is involved.
— check shower control and pressures.
2. Wire pit overflow to couch pit.
— correct wire pit overflow and avoid excess dilution of stock in broke system.
3. Inadequate repulping capability in couch pit.
— must be modified so full width breaks can be handled.
4. Check all pumping practices and controls around broke handling system.
5. Ensure that pumps are designed for expected high flows required.
— check length of suction lines on pumps.
6. Check couch pit control schemes.
— ensure that controls are properly maintained.
7. Check speed of dry broke conveyor.
— when slower than machine speed, too much broke can accumulate on conveyor.
8. Broke follows conveyor belt on return run; not falling into pulper.
— check knock-off showers for water pressure, plugged nozzles, shower angles, placement, etc.
9. Broke floats in pulper.
— broke pulpers must be capable of submerging the broke and slushing it as fast as it comes off the machine.
— adjust shower placement, position.
— check recirculation.
— ensure sufficient agitation to pull stock into rotor zone.
10. Level varies in broke pulper.
— check for level sensor being plugged with stock.
11. Check for worn rotors and extraction plates.
— adjust wiper clearance on wiped extraction plates.
— check for plugged extraction plates that can starve pumps.
12. Check pump capacities.
— undersized or under-powered systems cannot keep up.
— pulping and/or pumping capacities often do not kept pace with machine rebuilds or speed increases.
13. Broke chests.
— ensure that there is sufficient capacity; most paper machine systems suffer from lack of broke chest capacity.
— check agitation and controls.
— ensure proper consistency for storage.
14. Control systems.
— ensure all controls are properly tuned and maintained.
— poor consistency control will upset entire system and adversely affect paper machine operation.
15. White water dilution varies.
— especially true on sheet breaks where demands for white water are large.
— ensure adequate white water storage capacity.