Improvements in Paper Pulp Refining Engines.
Year: 1899

page_text: PROVISIONAL SPECIFICATION.
Improvements in Paper Pulp Refining Engines.
We, DAVID PEARSON, of Shotley Grove, Shotley Bridge, Durham, Manager,
and DAVID NOBLE BERTRAM, of the Firm of Bertrams, Ltd., St. Katherine's
Works, Sciennes, Edinburgh, Engineer, do hereby declare the nature of this
invention to be as follows;-
These improvements have reference to the construction of refining engine
forming the subject of Letters Patent No. 11956 A.D. 1893, and have for their
object to so feed the pulp into the engine as to ensure of the more effective
operation of both sets of cutterbars or discs, since with the pulp fed in at one
side as described in the said previous specification, the pressure of the pulp,
especially when fed by a pump, tends to press the central disc forward against
the fixed disc and thus cause more wear on one set of bars than on the other and
in fact render one set only fully operative.
According to our invention which has for its object to render both sets entirely
operative as aforesaid, or to counter-balance the pressure of the pulp, we feed
the pulp into the engine at both sides, i.e., through both outside discs, or into
the spaces on both sides of the central disc, and for that purpose we employ
inlet pipes of like area or capacity, connected to the same feed-box or pump, sup-
plying pulp under the same head" or pressure, and thereby equalising the
pressure on the central disc and causing it to be unaffected by the pressure of
pulp.
"
To permit of such double or duplex feed, and allow of the necessary adjustments
of the front disc, we employ a flexible tube, sliding gland or like connection for
the front inlet pipe.
The discharge outlet is, by preference in the side of the engine casing, and for
the purpose of regulating the amount of discharge (and simultaneously regulating
the amount of pulp admitted) we provide the said outlet with a regulating cock.
We may also provide the inlet pipe, or pipes with a regulating cock when fed
from a feed-box, but dispense with such cock when the pulp is supplied by a pump.
Damber 1800

page_text: Works, Sciennes, Edinburgh, Engineer, do hereby declare the nature of this
invention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement:-
__
These improvements have reference to the construction of refining engine
forming the subject of Letters Patent No. 11956 A.D. 1893, and have for their
object to so feed the pulp into the engine as to ensure of the more effective
operation of both sets of cutter bars or discs, since with the pulp fed in at one
side, as described in the said previous specification, the pressure of the pulp,
especially when fed by a pump, tends to press the central disc forward against
the fixed disc, and thus cause more wear on one set of bars than on the other, and
in fact render one set only fully operative.
According to our invention which has for its object to render both sets of cutters
entirely operative, as aforesaid, or to counter-balance the pressure of the pulp,
we feed the pulp into the engine at both sides, i.e., through both outside discs,
or into the spaces on both sides of the central disc, and for that purpose we employ
inlet pipes of (by preference) like area or capacity, connected to the same feed-
box or pump supplying pulp under the same "head" or pressure, and thereby
equalising the pressure on the central disc, and causing it to be unaffected by the
pressure of pulp.
"
To permit of such double or duplex feed, and allow of the necessary adjustment
of the front disc, we employ a flexible tube, sliding gland or like connection for
the front inlet pipe. The discharge outlet is, by preference, in the side of the
engine casing, and for the purpose of regulating the amount of discharge (and
simultaneously regulating the amount of pulp admitted) we provide the said
outlet with a regulating cock.
We may also provide the inlet pipe or pipes with a regulating cock when fed
from a feed-box, but dispense with such cock when the pulp is supplied by a pump.
To make our improvements perfectly clear we have hereunto attached a sheet
of drawings and with the aid of the figures and reference letters marked thereon
will more fully describe the same.
Fig. 1 illustrates a sectional elevation, and Fig. 2 a sectional plan of a refining
engine embodying our improvements.
A) designates the pulp refining chamber through which a shaft (B) passes,
and upon which shaft a disc (C) is mounted. (D) is a fixed and (E) a loose
adjustable end, and upon such ends, and upon the opposite faces of the disc (C).
are sets of cutters (F), (G), (H) and (I). The loose end (E) is adjusted by screw (J),
and to permit of the cutters (H) approaching cutters (1) the disc has (or may have)
a slight endwise movement, or the end (D) may also be loose and be adjusted in
accordance with the invention covered by Letters Patent No. 1390/97.
In each end disc we form an inlet opening (K) and to such opening, we connect
an inlet supply pipe (L). Both pipes lead from the same source of supply, i.e. an
overhead tank, or a pump, delivering the pulp at the same pressure through each
pipe. With the end (1) fixed the pipe (L) is connected by bolts and flange, but
with the end (E) loose and adjustable the connection is effected by a leather tube,
or sliding gland (M), as illustrated in Fig. 1, to allow for the movements of the
end, and still maintain the joint. If the end (D) is also loose and adjustable, the
gland or leather tube is used with that also.
A
The effect of the pulp flowing into the chamber (A) at opposite sides of the
disc (C), and at the same pressure, is to render the disc neutral to the pressure,
and thereby ensure of the more regular action and, even wear of the cutters.
further advantage of the double feed is that thicker pulp can be passed through
the engine than is possible with the single feed.
The pulp leaves the chamber (A) through the side outlet (N), under control of
a valve (0), and is delivered into a tank (P). Each inlet pipe (L), or the pipe
which joins them to the tank or pump, may have a valve..
1

page_text: Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is:
In paper pulp refining engines of the kind described, a refining chamber with
loose, or fixed and loose ends, a rotary disc between such ends, and cutters thereon,
in combination with inlet supply pipes opening into the chamber through each
end, or upon each side of the disc, and such pipes coupled to, or leading from the
same supply tank or pump, substantially as and for the purposes herein set forth.
Dated this 19th day of September 1900
DAVID PEARSON.
DAVID NOBLE BERTRAM.
By John G. Wilson & Co., Fels.Inst.P.A.,
Manchester.