NEWSPRINT . 263

The method of breaking that is still the most popukr is to use the common
type of breaker having a roll fitted with bars that are saw- or wavy-edged.
The bars are usually equally spaced round the roll about 18 inches apart, and
there is no bed-plate. The roll operates in a fixed position about 6 inches above
the bottom of the breaker trough, and it is not adjustable or counterbalanced
like a beater roll. Breakers of this type for newsprint stock are built to hold
about i ton (air-dry weight) of pulp at a consistency of 5 to 6 per cent, the
capacity of the trough being about 4500 gallons. Bales are fed by hand, a
few laps at a time, into the breakers just in front of the roll, the fining opera-
tion taking altogether about 10 minutes. After a total period of 20 or 30
minutes, including filling in, the stock is sufficiendy broken up to be dropped
to the breaker chest*

MtOTfCTEO BY U S,PAT.l,«*O.M* AND FORCIGM PATENTS. OTHEft P*Tt*TS f
[Sturtevant Mill Cc.t Boston, Mass.
Etc. ii2.—STURTEVANT BAIE PUIPER
Accepted stock has to pass through die semicircular perforated screen plate
Although this method of breaking appears, on the face of it, crude and
unscientific, and represents no advance, other than in the capacity of the breaker,
over methods that have been in use for very many years, it compares surprisingly
well in labour and power costs, and in capital expenditure, with proposals
made from time to time with a view to modernising lite procedure and reducing
the amount of man-handling required.
Among these proposals may be mentioned the Sturtevant pulper, which is
illustrated in Fig. 112. With this equipment, bales are mounted on a conveyor
which carries them continuously to a revolving drum fitted with claws that
tear at the surface of the pulp and effectively break it up. A shower of back-
water plays on the surface where disintegration takes place, and die resulting
slush fells below into a breaker chest