Substances for the Production of Paper Stock.
Year: 1888

page_text: Date of Application, 1st June, 1888
Specification Accepted, 17th Aug., 1838
[Communicated from abroad by JOHN A. MANNING and WILLIAM M. PECKHAM,
Manufacturers, and ADELBERT CHAMBERS, Engineer, all of Troy, New York,
United States of America.]
Substances for the Production of Paper Stock.
I, HENRY HARRIS LAKE of the firm of Haseltine, Lake & Co., Patent Agents,
Southampton Buildings in the County of Middlesex 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 :-
This invention has for its object, Treating Vegetable substances for making Paper-
stock, as fully set forth in connection with the following description. Similar letters
refer to similar parts in the drawings, in which Fig. 1-is a central vertical section of
the digesting and auxiliary reservoirs, and shows the piping, tubing, and various other
parts in elevation. Fig. 2-is a top plan view of the apparatus. Fig. 3-is a view
in side elevation of the annular perforated "Blow-off" pipes detached from the
digester to better illustrate their connection with the condensing reservoir, shown in
vertical central section and not shown in Figs. 1 and 2. Fig. 4-is a top plan view
of the blow-off pipes detached, and having the connections broken away. A-is the
digester-shell or reservoir, provided with the upper manhole L-through with the
material to he converted into paper-stock is introduced, and the lower man-holes P-
from which the material can be removed after treatment; also with various inlet
and outlet pipes, hereinafter more particularly described. B is an upper auxiliary
reservoir, which may be superimposed upon the digester A-as shown, or located any
desired distance above the same.
The two reservoirs are connected by one or more pressure equalizing tubes, R-
provided with check-valves located preferably, at their upper ends, to resist downward
pressure. Their lower ends may be protected by screens i. As the digester is
supplied through man-hole Lwith the material to be treated,, the cooking-liquor
is introduced through pipe H-into the upper end of the digester by means of a
pump E-in pipe F. The digester is only partly filled, having an air space or
dome D-for floating foreign substances, (shown above the broken line C).
After the digester has been filled to the proper height, which is about the relative
height shown by broken line C-it is tightly closed and steam at low pressure is
introduced through pipes J-in the bottom until the mass is heated to about the
boiling point.

page_text: The space D-affords ample room for the water of condensation. Any excess of
pressure in the space D-is immediately communicated through tubes R-to the
auxiliary reservoir; but the check-valves in tubes R-prevent the communication
through the tubes of any excess of pressure in the auxiliary reservoir to the digester.
When the cooking-liquor has been heated to about boiling-point, a portion is
pumped from the bottom of the digester through pipes F-and G-by means of
a pump E-into the auxiliary reservoir, valves e-being closed.
The pumping may continue until the reservoir is filled, and the valves in tubes R-
closing, the pressure is raised to a certain point necessary to open the spring or weight
controlled valve Q-when the liquor will be forced down pipe Q-into the digester
through the central part of its bottom, at Q-with a force equal to about the
difference between -the-internal pressure of-the-digester and the resisting pressure of
valve Q which may be adjusted as desired by regulating the tension of the spring,
and provided the pump is continuously operated with sufficient force to overcome the
resistance of the spring or weight W-the pipe a-being provided with a closed
valve a (Shown on one side by dotted lines). When desired, the pump may be
stopped after the auxiliary reservoir is filled, valve Q-being removed or held open,
and the contents of the reservoir allowed to flow by force of gravity back into the
digester through pipes Q-and Q2-as before described, after which the pump is
operated again to refill the auxiliary reservoir, the contents of which are allowed to
flow by gravity back into the digester, and the operation continued until the material
is thoroughly and evenly cooked or digested. When the pump is operated to fill the
digesting reservoir, the two-way valve is turned to connect pipe H-with pipo F.
In filling the auxiliary reservoir the valve is turned to close pipe Hand open
pipe to that reservoir.
The contents of the auxiliary reservoir can be forced into the digester in various
other ways, as by opening valves Q-and e-closing valves n--and operating
pump Eto draw out the contents through pipes Q-a-and F and force it through
pipes -Qand Q-or by admitting live steam of greater pressure than the internal
pressure of the digester into the top of the auxiliary reservior, as through a pipe g
(shown by dotted lines) valves Q-and being left open and valve e-or s-being
closed. When desired, the liquor can be drawn by the pumps through pipes G-F-
and forced directly back through pipes F-a-Q-and Q-valves aand being
open, and valves s-en-and Q-being closed, thus dispensing with the use of the
auxiliary reservoir.
The contents of the auxiliary reservoir can be forced into the digester in other ways,
as by the pump E-where the pipes F-and Q-are connected, as by pipes a-and
d-having a closed valve b-and open valve eor by admitting live steam of greater
prossure than the internal pressure of the digester into the top of the auxiliary
reservoir, as through a pipe -(Shown by dotted lines). The mouths of pipes G-
J and Q in the bottom of the digester are protected by suitable screens or
perforated diaphragms M-N, which may be of any desired size or form. I have
shown two pipes Q-and F-leading from one reservoir to the other; but there may
be any desired number, the pipes Q-leading from the lower part of the auxiliary
reservoir to the lower central part of the other reservoir or digester, and the pipes F-
leading from the upper part of the auxiliary reservoir to the lower outer portions of
the reservoir as through pipes G. The valve K-in the pipe K-serves to draw off
from the digesting-reservoir the liquor when the operation of cooking the material is
completed.
The connection of the various pipes and location of pumps and valves, may be.
changed, as desired, to conduct the liquor from one reservoir to another, or from.
one part of the digesting-reservoir to another part, substantially as described. The
action of the liquor upon the material to be digested or cooked depends in a great
measure upon the temperature of the ingredients.
It is of the utmost importance, therefore to maintain as nearly as possible a uniform
temperature throughout the mass, lest some portions should be cooked too much, or
65 burnt," while other portions are cooked too little or left "raw." Various devices.

page_text: have been employed for agitating the mass and distributing the heat supplied thereto.
Dixon and Harding as far back as 1866-procured U.S. patent No. 54,510 for an
apparatus which pumped the liquor from the bottom of the digester and forced it in at
the top to produce a current circulation downward through the mass, and more
recently an apparatus has been described and a process patented in the United States
by J. D. Tompkins, No. 340,640--purposing to alternately pump the liquor from the
bottom into the top to produce a downward current and from the top into the bottom
of the digester to produce an upward current in the liquor; but the liquor in the
upper part of the digester contains. so much fine fiber and foreign substances which
cannot be kept from the pump that the latter soon clogs and becomes inoperative. In
the use of my improved apparatus I do not reverse the currents in the liquor which
are constantly maintained in an upward direction through the inner central portion of
the material and a downward direction through the outer or surrounding portions.
The steam enters centrally through the bottom, as through pipes J-J,-which first
heats the central portion, and the heated liquor rises, the cooler liquor coming in from
the sides to take its place, thus producing the central upward and outer downward
current in the direction shown by the arrows. By pumping the liquor for a brief
interval from the bottom of the downward current, it is secured free from the small
light fibers and in its coolest condition. As it is pumped out it is either forced up
into the upper reservoir and caused to flow by gravity or otherwise back into the
bottom of the digester through pipe Q2-between the steam inlets J-or it is forced
directly into the digester through the various pipes, as before explained.
In either case it is reheated by the surrounding steam as it enters the digester and
again sent up through the central portion of the material:
As the only downward current produced is induced by the difference in gravity of
portions of the liquor resulting from difference in temperature, the lighter fibers and
foreign substances are left to float on the top upon the surface of the liquor, and are not
forced into, but gradually out of, the mass of material being treated the latter being
left comparatively clear and free from waste- substances. The space D-not only
provides room for floating the waste material, but affords ample space for the water
of condensation of the incoming steam. The upper ends of the digester and
auxiliary chambers are each provided with a "blow-off" pipe, 1--and 2 consisting
of an annular tube provided with numerous small perforations on the lower side.
These pipes are connected, as by sections 3- and 4-with a pipe leading to a
condensing reservoir 6.
The condensing reservoir is a tight inclosure, provided with valve 7-and a valved
outlet 8.
The pipes 4 are each provided with a valve 9. By means of this part of the
apparatus I am able to blow off, and separate from the disentegrated fiber, the foam,
oils, dissolved gums, and the cooking-liquors adhereing thereto, and force them into
the condensing reservoir from whence they may be drawn off by gravity, and treated,
to reclaim a good share of the cooking-liquors."
The pressure in the digester and auxiliary reservoir may be made very considerable
by admitting live steam or by means of the pumps, so that it is only necessary there-
after to open the valves 9-to blow off through the annular perforated tubes. The
tubes are provided with the small perforations to act as a strainer and prevent the
escape of the disentegrated fiber.
The tubes may simply have valved outlet pipes leading without the chambers when
it is not desired to reclaim the liquors.
Having now particularly described and ascertained the nature of my said inven-
lion and in what manner the same is to be performed, as communicated to me by
my Foreign Correspondents I declare that what I claim is-
First The combination with a digesting-reservoir provided with a lower steam-
supply pipe or pipes, of an auxiliary reservoir connected with said digesting-reservoir
by one or more pipes leading exteriorly from its upper end to the upper interior of the
auxiliary reservoir and one or more pipes connecting said reservoirs at or near their

page_text: lower ends, the latter pipes being severally supplied with a pump and valves, sub-
stantially as described.
Second An apparatus for treating vegetable substances for making paper-pulp,
consisting of a close reservoir provided with an upper float-waste dome, lower central
steam-supply pipe, and inlet liquor-pipes connected with the outlet liquor pipe or pipes
and supplied with a pump or pumps, substantially as described.
Third The combination with a digesting-reservoir provided with a lower steam-
supply pipe, of an auxiliary reservoir provided with an upper steam-supply pipe, and
connected at its lower end with the lower end of said digesting-reservoir by pipes,
one or more of which are supplied with a pump, substantially as described.
Fourth-In an apparatus for digesting vegetable and other substances, the combina-
tion with the digesting reservoir of a perforated blow-off pipe located in the upper part
of its interior, and provided with valved connections leading exteriorily of the reservoir,
substantially as described.
Fifth The combination with a digesting-reservoir, of an auxiliary reservoir, con-
nected therewith by a valved pipe supplied with a pump; and a perforated blow-off
pipe having valved connections leading exteriorly of the reservoir, substantially as
described.
Sixth The combination with a digester-reservoir having steam and pump-supply
pipes of a blow-off pipe, located in its upper part; an exterior condensing reservoir;
and valved connections leading from said blow-off pipe to said condenser, substantially
as described.