IMPROVEMENTS IN APPARATUS FOR THE MANUFACTURE OF WOOD OR OTHER PULP FOR PAPER MAKING AND SIMILAR PURPOSES."
Year: 1880

page_text: LETTERS PATENT to Carl Emil Hæger, of Kolback, in the Kingdom of Sweden,
but temporarily of the Office for Patents, 323, High Holborn, in the County
of Middlesex, for an Invention of "IMPROVEMENTS IN APPARATUS FOR THE
MANUFACTURE OF WOOD OR OTHER PULP FOR PAPER MAKING AND SIMILAR
PURPOSES."
PROVISIONAL SPECIFICATION left by the said Carl Emil Hoeger at the
Office of the Commissioners of Patents on the 13th December 1880.
CARL EMIL HÆGER, of Kolback, in the Kingdom of Sweden, but temporarily
of the Office for Patents, 323, High Holborn, in the County of Middlesex.
"IMPROVEMENTS IN APPARATUS FOR THE MANUFACTURE OF WOOD OR OTHER
PULP FOR PAPER MAKING AND SIMILAR PURPOSES."
In treating wood or other materials with chemicals for converting them into
pulp for paper making, etcetera, cylindrical boilers made of plain iron plates rivetted
together have been generally adopted, and are still almost universally in use;
but on account of the difficulty or impossibility of keeping the joints tight, in
consequence of the expansion and contraction occasioned by the direct firing
under the boilers, many firms have adopted the plan of using a separate steam
generator. This, however, involves greater expense, not merely in first cost and
in keeping the apparatus in repair, but also in the manufacture of the pulp itself.
To avoid these drawbacks to both systems I have invented my improved apparatus,
by the use of which I am enabled to employ the system of direct firing without
fear of leaky joints, and can produce a better quality of pulp.
The boiler then which I adopt is, by preference, cylindrical and composed of
corrugated plates welded together longitudinally (or parallel to the longer axis of the
cylinder), and the cross joints, if such be necessary, being screwed or rivetted
securely. By this means ample accommodation is provided for the expansion and
contraction, and the principal cause of leakage avoided thereby.
In the ordinary apparatus the circulation of the liquor is caused only by the

page_text: application of the heat at the bottom, but in my boilers I employ a special
contrivance for this purpose. Inside the boiler I have a light perforated cylinder
or casing of sheet iron, or the like, and nearly as large as the boiler, but leaving a
clear space all round, having its bottom (I am describing a vertical boiler) provided
with a sectional grating fitted with hinges and bolts so that the sections can drop
down when required. Down the centre of this perforated casing runs a perforated
pipe open at the bottom and communicating with a somewhat larger and short
piece of pipe at the top, within which is placed a small propeller actuated from the
outside by means of a spindle working through stuffing box. A stout cover of
cast or wrought metal closes all in; both cover and inner casing are removable by
a crane or other appliance provided for the purpose. A pipe communicates with
the boiler for filling it with liquid. The action is as follows:-The casing being
filled with the broken wood or other material to be operated upon is placed in the
boiler and the cover put on, and the remaining space filled with liquor through the
pipes; the fire is applied and the propeller set in motion. This draws the liquor
from the top (the short pipe is perforated for the purpose) and forces it down the
long perforated pipe, some of it escaping all the way along, and some passing out
at the bottom; this secures a far more perfect circulation than could be obtained
by the old plan.
When the boiling is finished the cover is removed, and then the casing containing
the pulp, which is emptied and again filled and replaced in the boiler. A blow off
pipe or cock and safety valve are of course used if desired, and the boiler can be
set horizontally, vertically, or otherwise, according to circumstances; I however
prefer the vertical arrangement for several reasons, as saving space, giving an
easier circulation, etcetera. Generally I prefer to have two inner casings, so that
one can be filling with wood, etcetera, whilst the other is in the boiler; this saves
time. The boiler may be set in brickwork as usual.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Carl Emil Hæger in the Great Seal Patent Office on the 13th
June 1881.
CARL EMIL HŒGER, of Kolback, in the Kingdom of Sweden, but temporarily
of the Office for Patents, 323, High Holborn, in the County of Middlesex.
'IMPROVEMENTS IN APPARATUS FOR THE MANUFACTURE OF WOOD OR OTHER
PULP FOR PAPER MAKING AND SIMILAR PURPOSES."
In treating wood or other materials with chemicals for converting them into
pulp for paper making, etcetera, cylindrical boilers made of plain iron plates
rivetted together have been generally adopted, and are still almost universally in
use; but on account of the difficulty or impossibility of keeping the joints tight, in
consequence of the expansion and contraction occasioned by the direct firing under
the boilers, many firms have adopted the plan of using a separate steam generator.
This however involves greater expense, not merely in first cost and in keeping
the apparatus in repair, but also in the manufacture of the pulp itself. To avoid
the drawbacks to both systems I have invented my improved apparatus, by the
use of which I am enabled to employ the system of direct firing without fear of
leaky joints, and can produce a better quality of pulp.
The boiler then which I adopt is, by preference, cylindrical and composed of
corrugated plates welded together longitudinally (or parallel to the longer axis of
the cylinder), the cross joints, if such be necessary, being bolted or rivetted
securely. By this means ample accommodation is provided for the expansion and
contraction, and the principal cause of leakage avoided thereby,
In the ordinary apparatus the circulation of the liquor is caused only by the
application of the heat at the bottom, but in my boilers I employ a special
contrivance for this purpose. Inside the boiler I have a light perforated cylinder
or casing of sheet iron, or the like, and nearly as large as the boiler, but having a
clear space all round between the casing and the shell, having its bottom (I am
now describing a vertical boiler) provided with a sectional door fitted with hinges
and bolts, so that the sections drop down when required. Down the centre of this
perforated casing runs a perforated pipe open at the bottom and communicating
with a somewhat larger and short piece of pipe at the top, within which is placed
a small propeller actuated from the outside by means of a spindle working through
a stuffing box. A stout cover of cast or wrought metal closes all in; both cover
and inner casing are removable by a crane or other appliance provided for the
purpose. A pipe communicates with the boiler for filling it with liquor. A blow
off pipe or cock and safety valve are of course used if desired, and the boiler can be
set horizontally, vertically, or otherwise, according to circumstances; I however
prefer the vertical arrangement for several reasons, as saving ground space, giving
an easier circulation, etcetera. Generally I prefer to have two inner casings, so
that one can be filling with wood, etcetera, whilst the other is in the boiler; this
saves time. The boiler may be set in brickwork as usual.
Reference being now had to the accompanying Drawings in which like letters
represent like parts. Fig. 1 is a sectional side elevation of the improved apparatus,
the boiler being set vertically in brickwork, and fired externally from underneath;
Fig. 2 is a side elevation of the same, but not in section, and at right angles in
plan to Fig. 1; Fig. 3 is a sectional plan upon line Y, Z, of Fig. 1; Fig. 4 is a plan

page_text: sections, which may be hinged and bolted or otherwise suitably secured; the
sections are let down when required to empty the casing, otherwise they are
retained by the shutter bolts B2; C is the long perforated pipe opening into the
bottom of the boiler; C₁ is the enlarged top, also perforated within, which is the
internal pipe E having holes or perforations E¹ above the propeller D, which is
driven through shaft D¹ by pulley D², or in some other convenient manner; a
stuffing box A² keeps all tight. A rubber disc I is placed for the end of pipe E to
bed on and make a tight joint. A bearing is provided for the propeller at D³;
F is the pipe through which the liquor is fed, and G is the blow off pipe.
WORKING.
The casing B having been charged with the wood or other material to be
operated upon is placed inside the corrugated shell A, and the cover put on and
secured, all as shown in Fig. 1. The liquor is then let in through the pipe F,
Fig. 2, the fire applied, and the propeller D or its equivalent set in motion. This
draws the liquor from the top through the perforations in C₁ and the holes E' of
pipe E and forces it down pipe C, some of it escaping through the holes all the way
down, and some passing out at the bottom. The rising again of the liquor is assisted
by the heat of the fire, and a very thorough circulation is thus obtained. When
the boiling is finished, the time to be occupied thereby varies with circumstances,
and can be ascertained by any of the methods usually adopted, the liquor is blown
off through pipe G in the usual manner, the cover A³ released by slackening the
holding down bolts, and removed by a crane, the pipe E and propeller D which
are connected to it coming away with it. The perforated cylinder B with pipes C
and C¹ which are attached to it is now removed by the crane, the sectional shutters
at the bottom opened, and the casing emptied. These boiling cylinders can also
be used with advantage in those places where they employ a separate steam
generator, for not even by this latter system can tight joints be permanently
maintained. As already stated, these cylinders can be laid horizontally or otherwise
according to circumstances, and may, if desired, be employed without the circulating
apparatus, though I much prefer to use it. In place of the sectional shutters B₁
I could of course employ a single door similarly hinged and bolted, but the sectional
arrangement is preferable.
Having now described my Invention, and the method of performing the same,
wish it to be understood that I am aware that all the separate parts of this apparatus
are not novel, as for instance, the long perforated pipe C and the simple perforated
casing B (I believe there are two forms of this casing in use, one is for horizontal
boilers, which is mounted on wheels to draw in and out; the other is hardly a
casing at all, properly speaking, and consists in perforated plates secured to the side
and end of a revolving boiler; however, I do not claim the casing without my
improvement, viz., the door or shutters at the end), and that I do not claim such
separate parts, but that what I do claim, and desire to protect under the herein-
before in part recited Letters Patent is,―
First. The employment of corrugated metal plates having welded longitudinal
joints in the construction of boilers for treating wood or other materials with
chemicals for converting them into pulp for paper making and similar purposes,
substantially as and for the purposes set forth and shown.
Second. In a boiler for treating wood and other materials with chemicals for
converting them into pulp for paper making and similar purposes, the employment
of the perforated casing B provided at its inner end with hinged shutters or their
equivalent B', said casing being so arranged that it may be readily withdrawn

page_text: from the boiler and the contents discharged from the end by opening of said shutters,
substantially as and for the purposes set forth and shown.
Third. In a boiler for treating wood and other materials with chemicals for
converting them into pulp for paper making and similar purposes, the employment
of the propeller D or its equivalent for the purpose of producing a better circulation
of the liquor, substantially as set forth and shown.
Fourth. As an apparatus or means for circulating the liquor in boilers for the
treatment of wood or other materials with chemicals for converting them into pulp
for paper making and similar purposes, the propeller D with its shaft D₁ and
pulley D² and pipe E pierced as at E¹, all connected to and removable with the
cover of the said boiler, in combination with the perforated outer pipe C¹ and long
perforated pipe C, substantially as set forth and shown.
In witness whereof, I, the said Carl Emil Hæger, have hereunto set my
hand and seal, this Fourth day of June, in the year of our Lord One
thousand eight hundred and eighty one.