Operating manual 17.410+411
Pos.: 20
Dateiname
Firma
Datum
Rev
BK-DH 700 x 1000 eng.doc
BRUKS-KLÖCKNER
27.02.09
00
Seite 17 von
61
3.2
Functional description
3.2.1 Stock feed
The material to be chipped is fed to the chipper by a belt or vibratory feeder. The up-
per and lower feedrolls positively grab the material and push it to the rotor at a con-
trolled rate. The upper feedrolls adjust for height of the material to be chipped.
The pressure of the upper feedrolls on the material is generated by the weight of the
feedroll carrier and the hydraulic cylinders are used to reduce this pressure to the
minimum required for proper feeding. This will extend life of the feedroll teeth and re-
duce damage to the wood.
3.2.2 Chipping operation
The knives chip the material by cutting the length of the chip with the thickness re-
sulting from the knife angle and specific characteristics of the wood being chipped.
The chips are collected in the pocket below the knife and carried past the anvil. The
chips are now thrown out by centrifugal force, with the oversize pieces held back by
the screen and chipped again.
3.2.3 Material distribution
The funnel under the chipper embraces the whole scuttle of the machine. Also fine
material under the feedrolls would be taken and lead in the following conveyor.
3.2.4 Overload protection
For preventing overload of the main motor, the drum chipper is fitted with a load-
depending feed control. With the power consumption of the main motor reaching
rated current, the feed motors are disconnected (time-delayed). They are automati-
cally reconnected if the power consumption of the main motor drops to 70% of the
rated value
