Improvements in Disintegrating Fibrous Substances and Manu- facturing Paper Pulp and in Apparatus Employed therein.
Year: 1886

page_text: Date of Application, 4th Dec, 1886
Complete Left, 30th Aug, 1887.
Complete Accepted, 7th Oct., 1887
Improvements in Disintegrating Fibrous Substances and Manu-
facturing Paper Pulp and in Apparatus Employed therein.
1, HENRY BLACKMAN, residing at 69 East 130th Street, in New York, United
States of America, Engineer, do hereby declare the nature of said invention for
"IMPROVEMENTS IN DISINTEGRATING FIBROUS SUBSTANCES AND MANUFACTURING
PAPER PULP AND IN APPARATUS EMPLOYED THEREIN to be as follows:-
"
This invention relates to the manufacture of paper-pulp from wood, straw, jute, or
other fibrous substances. It includes improvements both in the process of manufac-
ture and in the apparatus.
The improved process relates to, 1, the softening or dissolving of the fibrous matter
in a closed vessel or digoster; 2, the disruption of the fibres by "oxploding" them,
or suddenly liberating them from pressure; 3, the separation of gritty or hard
particles 4, the working apart of the fibres to reduce them to a homogeneous pulp,
in place of treating them in the "beating-engine" 5, the pulling apart of the fibres
which have resisted the pulping process; 6, the draining and washing of the fibres;
and, 7, the bleaching of the pulp.
1. The softening or dissolving of the fibrous matter is practiced in the following
manner.
If
I first introduce the fibrous matter into a digester in a comminuted condition.
wood is used, it is in the form of small chips or granules. The digester is closed, and
water is turned on, with or without other chemicals, steam is injected, and the mass
is boiled under pressure until the fibrous matter becomes softoned. The liquor is
pumped out and returned to the digester, thereby causing a circulation through the
mass. A vacuum valve in a pipe leading to a suction pump is then opened slightly, to
cause a circulation or outflow of any vapors, chemicals or impurities that may be at
the top of the mass, but without losing the pressure.
Gases or chemicals may be
forced through the mass while the boiling continues. The liquor is drawn off, and
any chemicals that may have been used are recovered. Steam is then injected into
the mass, the vacuum valve is fully opened, and the mass is boiled in vacuo for a
sufficient length of time, whereby all vaporizable impurities are carried off. Then the
valve is closed, the fibrous matter is drained of its liquor, and clean hot water is

page_text: introduced, and the mass is again boiled under pressure, with forced circulation, and
finally in vacuo again.
་་
When the fibrous mass contains a considerable proportion of impurities or foul
matters it is to be rinsed once or more during the treatment in the digester. I prefer
to draw off the foul liquor at the same time that the fresh liquid is introduced, which
is done by introducing the clean water at the bottom and simultaneously drawing off
the foul liquor at the top. The fibres, being thoroughly soaked by the previous
boiling, are heavy and do not float in the liquid, but lie while the liquid slowly rises
through them. The foul liquor is lifted by the water beneath it and flows out, the
process being continued until the liquid passes out clear.
When the rinsing is completed steam is turned on at full pressure and the mass
is boiled for a short time; the liquor being circulated as before described. Then the
vacuum-valve is opened, and the mass is again boiled in vacuo for a few minutes.
This completes the digesting process, and the fibrous matter is ready for the disrupting
operation.
In practicing this process any ordinary steam-pressure may be used, say from
10 to 100 pounds per square inch; and the vacuum should be about 27 inches.
2. The disruption of the fibres by "exploding" them, or suddenly liberating them
from pressure, is effected, according to my invention by charging the softened fibrous
material with fluid under heavy pressure, and forcing the same through a contracted
opening into a vacuum-chamber. On entering this chamber the pressure is relieved,
and the fluid under pressure in the interstices of the fibre suddenly expands, tearing
the fibres asunder. The vacuum is maintained by showering water into the chamber
to condense the expanded fluid and by drawing off the contents of the chamber by a
pump or other exhausting device.
I prefer to practice this process as follows:-The fibrous material having been
softened by the treatment in the digester, the digester is closed and steam is admitted
under heavy pressure. A valved outlet-pipe leads from the digester and terminates
in a contracted nozzle entering the vacuum-chamber. The outlet-valve is opened, and
the pressure forces the fibrous matter with the water and steam out through this pipe,
and it flows through the nozzle and into the vacuum-chamber in a reduced but con-
tinuous stream, the confined steam expanding as soon as it passes from the nozzle, and
tearing the fibres apart. The fibres are projected against a screen or target. A
shower of water condenses the steam, and the liquid, fibres, and vapors are drawn off
by a pump, ejector, or other exhausting device. To prevent the destruction of the
vacuum by the expansion of the steam in the vacuum-chamber, the nozzle is so con-
tracted that it admits the fibrous matter and fluid in so reduced a stream that the
expanding steam therefrom is of no greater volume than the capacity of the pump
will suffice to draw off.
The fibrous matter may be forced out from the digester with steam alone, and
without water, or even with other compressed gases, such as compressed air, it being
only essential that the fibres be thoroughly softened or dissolved, that the compressed
gas shall penetrate their interstices, and that the mass shall be able to flow properly.
It is preferable however to have the fibres saturated with superheated water, which on
being liberated from pressure expands into steam.
3. The separation of gritty or hard particles from the fibrous matter after its
disruption is effected by precipitation. The fibres and water are caused to flow very
slowly through a series of traps, wherein the currents are alternately downward and
upward. The heavy particles, such as grit or sand, and pieces of knots that have
resisted the dissolving process, fall to the bottoms of the traps, while the fibres are
carried by the liquid through the traps, and reach the pump without carrying with
them any gritty particles.
$9
4. The working apart or separation of the fibres to reduce them to a homogeneous
pulp, which has heretofore been done by the " beater-engine is accomplished
according to my invention by the agitation of the fibres in liquid by forcing the liquid
through an extended pipe or passage containing agitating obstructions. The obstruc-
tions may be stationary or movable; in either case they act to cause an eddying of

page_text: the current, and an impingement of the fibres against the obstructions, which loosens
the fibres and gently separates them, gradually reducing them to a uniform condition
of fine flocculence. By preference the liquid is passed first through an agitator con-
taining moving obstructions, which are reciprocated by power, and then through an
agitator containing stationary obstructions. The fibres and liquid emerge in the
condition of a liquid pulp.
5. In order to separate any fibres which may have resisted the gentler process of
agitation, I subject the liquid pulp to the action of scouring or scrubbing brushes
between which it is caused to flow. The scrubber consists of a passage in which are
placed brushes which are alternately stationary and movable, or which are both
movable, moving alternately in opposite directions, the moving brushes being either
reciprocatory or rotary (preferably the latter) and being driven by suitable power.
As the fibres are carried through by the current of water they are caught by the
brushes and drawn apart, and at the same time any impurities clinging to them are
rubbed off.
6. The washing or rinsing of the fibres is accomplished by conveying them in
draining buckets past or beneath a sprinkler, whereby not only is the old liquid
drained from them, but fresh water is sprinkled over them and drained through them,
thereby washing them. As the liquid pulp comes from the agitator or scrubber it
enters a conveyor and the fibres are carried up by a series of foraminous buckets,
which drain off the old liquid into a gutter, by which it is carried off. The fresh
water from the sprinkler enters the buckets, soaks through the fibres and runs off to
the gutter.
I employ by preference several successive agitators, with a draining conveyor
between each two agitators, so that the water is renewed before the pulp enters cach
new agitator. When the pulp is dumped from the buckets, at the top of the conveyor,
it meets a stream of water which washes it to a pump, and by this pump it is forced
through the next agitator.
7. The bleaching of the pulp I effect in an agitator, wherein the liquid pulp
encounters obstructions, as already described. As the pulp is dumped from the
draining conveyor, it is mixed with bleaching liquor and pumped through the
agitator, on emerging from which the bleaching liquor is drained off by another
conveyor, and is pumped back to be used again. The pulp, after being drained of
liquor, is mixed with fresh water and pumped through another agitator, in order to
rinse the fibres and remove from them any remaining traces of the bleaching chemicals.
The pulp is then ready for use in paper-making, or it may be formed into sheets
and dried, to be sold to paper mills.
I will now describe the apparatus forming part of my present invention, by which
the said processes are practiced.
1. For softening or dissolving the fibrous matter I provide a digester consisting of
an upright cylinder of iron or steel, lined with lead or other substance. One or more
perforated pipes (preferably four) pass vertically through the digester, and are
connected at their upper and lower ends to horizontal pipes, which in turn are in
connection with a steam-pipe, a water-pipe, a pipe leading to a tank of chemicals, a
pipe communicating with a vacuum-pump, and a pipe leading to and from a circulating
pump. Thus steam, water, or chemicals may be admitted through the perforated
pipes, or water, chemicals or vapors may be drawn off through them, and either
returned by the circulating-pump, or discharged. An exhaust-pipe leads from the
top of the digester to the vacuum-pump. At the top of the digester is a man-hole
through which to enter the fibrous material. At the bottom of the digester is an
outlet-valve, from which a pipe leads to the vacuum-chamber. A pipe enters this
valve, in order that when the valve is closed steam or water may be injected into the
outlet. In the bottom of the digester is a funnel-shaped screen, the outlet being at
its lower end, and from the space beneath this screen a drainage pipe extends and
joins the system of pipes beneath. All the pipes are provided with suitable valves.
The circulating-pipe passes through a heater or cooler, so that the temperature of the
liquid may be altered while it is being circulated.

page_text: The digester is made with a double shell, the space or jacket thus formed being
filled with water, which is kept in circulation by a special pump, which draws it off at
the top, passes it through a heater, and returns it to the bottom of the jacket. The
pressure in this jacket is kept the same as within the digester.
2. The mechanism for disrupting the fibres by "exploding" them into a vacuum,
consists of the digester just described, its outlet-valve, the outlet-pipe leading there-
from, which terminates in a contracted nozzle, a vacuum-chamber into which said
nozzle projects, and a pump, ejector, or other exhausting device for maintaining the
vacuum in said chamber. The vacuum-chamber is divided into two compartments by
a pendent partition or "target," against which the stream from the nozzle impinges.
In each chamber is a condenser, consisting of a perforated pipe which showers cold
water into the chamber. I employ by preference two pumps, one a vacuum-pump
for drawing off the vapors from the top of the vacuum-chamber, and the other a
force-pump for drawing off the liquid and fibres from the bottom of the chamber and
forcing them onward to the agitator." In the outlet-pipe to the vacuum-pump is
another perforated pipe for showering water.
፡፡
3. For effecting the separation of gritty or hard particles I provide the series of
traps hereinbefore described, and arrange them preferably between the vacuum-
chamber and the force-pump.
4. For working apart or separating the fibres to reduce them to a homogeneous
pulp, I provide what I call an "agitator," which is constructed by preference with an
outer casing so divided by partitions as to make a passage extending back and forth,
and in this passage are placed agitating obstructions, consisting of sheets of corrugated
metal. In the first divisions of this passage the obstructions are caused to reciprocate,
thereby forcibly churning the liquid as it flows through. The plates are alternately
fixed and movable, the movable plates being fixed in a sliding frame, which is
reciprocated by a piston-rod passing out of the casing through a stuffing-box, and
connected to a crank-shaft. In the remaining divisions of the passage, the obstruc-
tions are fixed and stationary.
"
5. For pulling apart the fibres which have resisted the action of the agitator I
provide a scrubber" which may be constructed in the same casing as the agitator,
and consists preferably of one or more cylindrical passages lined or clothed with
brushes, and a cylindrical brush mounted to rotate. in each such passage. The rotary
brushes are mounted on shafts which pass out through stuffing-boxes, and are rotated
by suitable gearing.
6. For draining and washing the fibres I provide a conveyor with draining-buckets,
as hereinbefore described, which is connected to the outlet from the scrubber. The
fibres dumped from the top of the conveyor are received in a funnel, into which a
stream of water is directed from a nozzle. The pipe from this funnel leads to a second
force-pump, which forces the pulp through a second agitator.
7. The bleaching of the pulp is effected by a second agitator. The fibres are
dumped from the top of the conveyor into a funnel, and a stream of bleaching liquor
is directed into the funnel. The pipe from this funnel leads to a second force-pump,
which forces the pulp and liquor through the second agitator. To the outlet from this
is connected a second draining conveyor, and from the draining gutter thereof a pipe
leads to a pump, and thence back to the funnel of the first conveyor.
From the second conveyor the pulp passes to a third force-pump, and is forced
through a third agitator, and from this it flows into a distributing trough, from which
it may be drawn off into either one of a series of "wet machines" or other known
apparatus for making it into sheets, or otherwise preparing it.
Dated the 3rd day of December 1886
J. C. MEWBURN,
169, Fleet Street, London,
Agent.

page_text: Improvements in Disintegrating Fibrous Substances and Manu-
facturing Paper Pulp and in Apparatus Employed therein.
1, HENRY BLACKMAN, residing at 69 East 130th Street, in New York, United
States of America, 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 :-
This invention relates to the manufacture of paper-pulp from wood, straw, jute, or
other fibrous substances. It includes improvements both in the process of manufacture
and in the apparatus.
The improved process relates to, I, the softening or dissolving of the fibrous matier
in a closed vessel or digester; 2, the disruption of the fibers by exploding" them,
or suddenly liberating them from pressure; 3, the separation of gritty or hard
particles; 4, the working apart of the fibers to reduce them to a homogeneous pulp, in
place of treating them in the "beating engine"; and 5, the pulling apart of the fibers
which have resisted the pulping process.
1. The softening or dissolving of the fibrous matter is practiced in the following
manner.
If
1 first introduce the fibrous matter inio a digester in a comminuted condition.
wood is used, it is in the form of small chips or granules. The digester is closed, and
water is turned on, with or without other chemicals, steam is injected, and the mass
is boiled under pressure until the fibrous matter becomes softened. The liquor is
pumped out and returned to the digester, thereby causing a circulation through the
mass. A vacuum valve in a pipe leading to a suction pump is then opened slightly, to
cause a circulation or outflow of any vapors, chemicals or impurities that may be at
the top of the mass, but without losing the pressure. Gases or chemicals may be
forced through the mass while the boiling continues. The liquor is drawn off, and
any chemicals that may have been used are recovered. Steam is then injected into
the mass, the vacuum valve is fully opened, and the mass is boiled in vacuo for a
sufficient length of time, whereby all vaporizable impurities are carried off. Then the
valve is closed, the fibrous matter is drained of its liquor, and clean hot water is
introduced, and the mass is again boiled under pressure, with forced circulation, and
finally in vacuo again.
When the fibrous mass contains a considerable proportion of impurities or foul
matters it is to be rinsed once or more during the treatment in the digester. I prefer
to draw off the foul liquor at the same time that the fresh liquid is introduced, which
is done by introducing the clean water at the bottom and simultaneously drawing off
the foul liquor at the top. The fibers, being thoroughly soaked by the previous
boiling, are heavy and do not float in the liquid, but lie while the liquid slowly rises
through them.
The foul liquor is lifted by the water beneath it and flows out, the
process being continued until the liquid passes out clear.

page_text: When the rinsing is completed steam is turned on at full pressure and the mass is
boiled for a short time, the liquor being circulated as before described. Then the
vacuum-valve is opened, and the mass is again boiled in vacuo for a few minutes.
This completes the digesting process, and the fibrous matter is ready for the disrupting
operation.
In practising this process any ordinary steam-pressure may be used, say from
10 to 100 pounds per square inch; and the vacuum should be about 27 inches.
2. The disruption of the fibers by "exploding" them, or suddenly liberating them
from pressure, is effected, according to my invention by charging the softened fibrous
material with fluid under heavy pressure, and forcing the same through a contracted
opening into a vacuum-chamber. On entering this chamber the pressure is relieved,
and the fluid under pressure in the interstices of the fibers suddenly expands, tearing
the fibers asunder. The vacuum is maintained by showering water into the chamber
to condense the expanded fluid and by drawing off the contents of the chamber by a
pump or other exhausting device.
I prefer to practice this process as follows:-The fibrous material having been
softened by the treatment in the digester, the digester is closed and steam is
admitted under heavy pressure. A valved outlet-pipe leads from the digester and
terminates in a contracted nozzle entering the vacuum-chamber. The outlet-valve is
opened, and the pressure forces the fibrous matter with the water and steam out
through this pipe, and it flows through the nozzle and into the vacuum-chamber in a
reduced but continuous stream, the confined steam expanding as soon as it passes
from the nozzle, andtearing the fibers apart. The fibers are projected against a screen
or target. A shower of water condenses the steam, and the liquid, fibers, and vapors
are drawn off by a. pump, ejector, or other exhausting device. To prevent the
destruction of the vacuum by the expansion of the steam in the vacuum-chamber, the
nozzle is so contracted that it admits the fibrous matter and fluid in so reduced a
stream that the expanding steam therefrom is of no greater volume than the capacity
of the condenser and pump will suffice to condense and draw off.
The fibrous matter may be forced out from the digester with steam alone, and
without water, or even with other compressed gases, such as compressed air, it being
only essential that the fibers be thoroughly softened or dissolved, that the compressed
gas shall penetrate their interstices, and that the mass shall be able to flow properly.
It is preferable however to have the fibers saturated with superheated water, which on
being liberated from pressure expands into steam.
3. The separation of gritty or hard particles from the fibrous matter after its disrup-
tion is effected by precipitation. The fibers and water are caused to flow very slowly
through a series of traps, wherein the currents are alternately downward and upward.
The heavy particles, such as grit or sand, and pieces of knots that have resisted the
dissolving process, fall to the bottoms of the traps, while the fibers are carried by
the liquid through the traps, and reach the pump without carrying with them any
gritty particles.
4. The working apart or separation of the fibers, to reduce them to a homogeneous
pulp, which has heretofore been done by the beater-engine is accomplished
according to my invention by the agitation of the fibers in liquid by forcing the liquid
through an extended pipe or passage containing agitating obstructions. The obstruc-
tions may be stationary or movable; in either case they act to cause an eddying of the
current, and an impingement of the fibers against the obstructions, which loosens the
fibers and gently separates them, gradually reducing them to a uniform condition of
fine flocculence. By preference the liquid is passed first through an agitator containing
moving obstructions, which are reciprocated by power, and then through an agitator
containing stationary obstructions. The fibers and liquid emerge in the condition of
a liquid pulp.
5. In order to separate any fibers which may have resisted the gentler process of
agitation, I subject the liquid pulp to the action of scouring or scrubbing brushes,
between which it is caused to flow. The scrubber consists of a passage in which are
placed brushes which are respectively stationary and movable, or which are both

page_text: movable, moving in opposite directions, and the moving brushes being either
reciprocatory or rotary (preferably the latter) and driven by suitable power. As the
fibers are carried through by the current of water they are caught by the brushes and
drawn apart, and at the same time any impurities clinging to them are rubbed off.
6. The washing or rinsing of the fibers may be accomplished by conveying them in
draining buckets past or beneath a sprinkler, whereby not only is the old liquid drained
from them, but fresh water is sprinkled over them and drained through them, thereby
washing them.
As the liquid pulp comes from the agitator or scrubber it enters a
conveyor and the fibers are carried up by a series of foraminous buckets, which drain
off the old liquid into a gutter, by which it is carried off. The fresh water from the
sprinkler enters the buckets, soaks through the fibers and runs off to the gutter.
I prefer however, to employ the ordinary rinsing tank or washer, which is well
known to paper makers.
7. The bleaching of the pulp may be effected in an agitator, wherein the liquid pulp
encounters obstructions, as already described. The pulp is mixed with bleaching
liquor and pumped through the agitator, on emerging from which the bleaching liquor
is drained off and pumped back to be used again. The pulp, after being drained of
liquor, is mixed with fresh water and pumped through another agitator, in order
to rinse the fibers and remove from them any remaining traces of the bleaching
chemicals. Or, this rinsing may be accomplished in the ordinary washer.
The pulp is then ready for use in paper-making, or it may be formed into shects
and dried, to be sold to paper mills.
I will now describe the apparatus forming part of my present invention by which
the said processes are practiced, referring for that purpose to the accompanying
drawings wherein
Figure 1 is a side elevation of the apparatus.
Fig. 2 is a plan thercof.
Fig. 3 is a vertical mid-section on a larger scale of a portion of the apparatus.
Fig. 4 is a transverse section of the digester.
Fig. 5 is a vertical section of the vacuum chamber and grit separator on a larger
scale.
Fig. 6 is a vertical mid-section of the agitator and scrubber on an enlarged scale.
Fig. 7 is a transverse section thereof.
Figs. 8 and 9 are enlarged fragments of the agitator.
Figs. 10, 11 and 12 illustrate modifications.
Referring first to Figs. 1 and 2, A designates the digester, B the vacuum chamber,
the grit separator, D and E the pumps, F the agitator, and G the scrubber which is
in the same casing as the agitator. These machines are connected together through
suitable pipes so as to operate in succession.
Figs. 3 and 4 show the digester A in detail. It consists preferably of an upright
cylinder of wrought iron or steel, with rounded bottom, and lined or coated internally
with some substance which will resist the corrosive action of the chemicals used for
treating the fibrous matter. At the top of the digester is a manhole a through
which to introduce the fibrous matter to be treated. At the bottom of the digester is
an outlet-valve L, from which a pipe L' leads to the vacuum-chamber B, which it
enters, its end being contracted to form a nozzle b. Within the digester are four
(more or less) perforated vertical pipes M. M. These are connected at the top to
horizontal pipes N N and at the bottom to horizontal pipes N' N¹. These pipes
N and N are in the form of rectangles. A steam-pipe S leads from a steam-boiler (not
shown) and enters the top of the digester, having a branch S3 which joins the pipes N.
A steam-pipe S joins the pipes N1, and has a branch S2 which enters the valve L. This
valve is a three-way valve, being adapted to connect the outlet of the digester with
either the outlet-pipe L or the steam-pipe S². A water-pipe W is connected with the
pipes N'. A pipe O leads from a tank A' (Fig. 1) for containing chemicals, and
connects with the pipes N and another pipe OT leads from this tank (or another
chemical tank) and joins the pipes N¹.
In the bottom of the digester is a conical perforated screen or grating c Cy inclined

page_text: toward the outlet L, and from beneath this grating a drainage-pipe 02 leads downward
to the pipes N. From the pipes N¹ a pipe leads to a pump P, which is shown as a
rotary or centrifugal pump (although any kind of pump may be used) and from this
pump extends a delivery-pipe P which leads upward and connects with the pipes N
at the top. By means of this pump a liquid can be drawn off from the bottom of
the digester, and forced in at the top, thus establishing a circulation. A heater or
jacket P is arranged to heat (or cool, as the case may be) the liquid passing through
the pipe P¹.
From the top of the digester a suction pipe E' leads to the vacuum-chamber B, and
from this chamber another suction pipe E leads to the pump E, from which a
discharge-pipe E3 extends to a condenser, or a tank or other dovice (not shown)
whereby the chemicals drawn off by the pump may be recovered. A branch pipe N'
connects the pipes N and P with the suction-pipe E.
The several pipes above referred to are provided with valves or cocks, as shown,
some of which are numbered respectively from 1 to 18, to control the flow of the
liquid through them.
The mechanism for disrupting the fibers by "exploding" them into a vacuum
consists of the digester A, its outlet-valve L, the outlet pipe L' leading therefrom and
terminated in a contracted nozzle b, the vacuum-chamber B into which said nozzle
projects, and a pump, ejector, or other exhausting device for maintaining the vacuum
in said chamber. The vacuum-chamber is partially divided by a vertical partition or
target d into two compartments B' and B2, as shown in Fig. 3. The entoring stream
from the nozzle impinges against this target. In each compartment is a condenser
In the
consisting of perforated pipes for showering water into the chamber.
chamber B are two perforated pipes e e, (Fig. 5) which shower water on opposite sides
of the nozzle. In the chamber B² there is one perforated pipe e¹.
I employ by preference, two pumps, one a vacuum pump for drawing off the vapors
from the top of the vacuum-chamber, and the other a force pump for drawing off the
liquid and fibers from the bottom of the chamber and forcing them onward to the
" agitator." From the upper part of the chamber B2 a suction pipe E' leads to
the vacuum pump E, its entrance being guarded by a shield e. In this pipe is a
perforated pipe e³ for showering water therein to condense any steam or vapor.
From the bottom of the chamber B2 an outlet pipe 6' leads down into the grit
separator C. This is a closed box in which is constructed a double series of traps or
pockets for catching grit, sand, and other heavy particles in the pulp, such as bits of
knots which have not been disintegrated. Beneath the inlet are two converging
partitions 2, (Fig. 5) and on each side of these is a dam c¹ over which the liquid
must flow, then a partition d' under which the liquid must flow, then another dam,
lower than the first, then another partition, and so on. As the liquid runs over the
last dam on each side, it falls on an inclined plate (Fig. 3) which carries it toward
the front, and it then runs back under the false-bottom of the traps, and out the
pipe D' to the force pump D. The delivery-pipe D from this pump leads to the
agitator F.
For working apart or separating the fibers to reduce them to a homogeneous pulp I
provide what I call an agitator which is shown at F and is illustrated in detail in
Figs. 6 to 9.
The agitator F is constructed with an outer box or casing h, in which are fixed
alternate partitions h¹², whereby is constituted a zig-zag or back-and-forth passage Q,
as clearly indicated in Fig. 6. In this passage Q are placed any kind of agitating
obstructions ii, adapted to impede the flow of the liquid pulp through the passage, and
cause a movement or circulation of the fibers relatively to one another. These
obstructions may be fixed or movable. As here shown, they are partly movable in the
first four sections of the passage Q, and are fixed in the remaining sections thereof.
The obstruction shown consist of sheets or plates of corrugated metal, with their
corrugations arranged transversely to the direction of flow of liquid through the
passage. These plates are set close together, so that the fibers in flowing between
them will be caused to impinge against their convox or projecting corrugations. The

page_text: plates in the first four sections of the passage are alternately stationary and movable.
The stationary plates are fixed in place within the casing. The movable plates Z
are arranged to slide in grooves at the sides of the casing, or otherwise mounted so
that they may slide or move longitudinally, in the spaces between the fixed plates.
Their upper ends are connected to a cross-frame or head j. This head is mounted on
a vertical rod which extends up through a stuffing-box, and is jointed at its upper
end to a pitman which embraces a crank k on a rotary shaft t. This shaft has
two cranks, oppositely placed, one being connected to the movable plates in the first
and second sections of the passage Q, and the other to the movable plates in the third
and fourth sections of the passage. As one set of plates moves up the other moves
down, and vice versa. If more than four sections of the passage are fitted with
movable plates, there will be one or more additional cranks, pitmans and rods. Any
other suitable mechanism may be used to reciprocate the movable plates. The inter-
vening plates may also be made movable, reciprocating oppositely to the plates 2, in
which case some mechanism such as that shown may be applied to move them.
In Fig. 6 I have shown an agitator having seven sections to its passage Q, four of
which are fitted with movable plates, and the remaining three with fixed plates. The
latter have their plates arranged as shown in the diagram, Fig. 8, so that the liquid
flows through in a sinuous sheet, moving from side to side, and impinging in its
The forcing of
passage against the salient projections on alternately opposite sheets.
the pulp through these sinuous spaces effects a gentle agitation, causing the fibrous
particles to move one upon another, and gently working apart any fibers that may be
clinging together. In the first four sections of the passage, the respective plates have
at one time the relative position shown in Fig. 8, and at another time that shown in
Fig. 9, being continually shifting from one position to the other. The stroke of the
movable plates should be equal to the combined widths of several corrugations, and
they should be reciprocated at sufficient speed to effect a somewhat violent agitation of
the liquid. The continual and rapid changes of shape of the passages between the
plates, due to their reciprocation, act to dash the liquid passing through them against
the corrugations, to throw it from side to side, and to churn it and beat it until the
fibers are separated from one another and cleansed by their attrition against one
another and by the rinsing of the liquid past them.
The separation of the fibers by the agitation of their liquid vehicle is the object of
this process, and this agitation may be effected in various ways, either by movable
obstructions moving against the liquid, or by stationary obstructions against which the
liquid is forced, or by the forcing of the liquid in a rapid stream through a passage
having frequent abrupt angles. The pipe or passage may contain any irregular
obstructions that are suited to the purpose, such as trimmings of sheet metal, bits of
wire gauze, and the like, provided only that they will not pack with the pressure of the
current, nor form pockets in which the fibers will precipitate and choke the passage.
From the agitator the fibers pass to the scrubber G, shown in Figs. 1, 6 and 7.
The scrubber is here shown as constructed in the same casing as the agitator, but this
is not essential. The agitator passage Q terminates at the top of the casing, and from
this the pulp flows across the top of two cylindrical passages R R, down those passages
to the bottom of the casing, and thence to the outlet G¹. The passages R R are
clothed with bristle-brushes, and in each passage is set a revolving cylinder T, which is
clothed exteriorly with bristle brushes. The cylinders T T are mounted on shafts T¹ T'
having bearings at top and bottom of the casing, extending out of the top of the
casing through stuffing boxes, geared together, and connected by a belt or otherwise
with a source of power, in order to be rotated. One of these shafts is also by preference
geared to the shaft 7 of the agitator.
The stationary brushes in the cylindrical passages R R and the moving brushes on
the rotating cylinders T T are arranged to barely touch each other as the cylinders
revolve. The pulp flowing down through the annular space between the two sets of
brushes is acted upon thereby, any fibers which may be still clinging together being
thus drawn apart.
The scrubber acts to complete the disintegration and separation of the fibers, doing
B

page_text: all that is left undone by the agitator, and the pulp comes from it with its fibers
reduced to a homogeneous flocculent condition. The scrubber might be used alone,
without the agitator, or it might be arranged to act first upon the pulp, passing it then
to the agitator, but I prefer the arrangement shown.
The scrubber may be modified In various ways. All that is essential is that the pulp
shall be acted upon by moving brushes, while it is held by stationary (or oppositely
moving) brushes, or by other equivalent device. Wire brushes might be used, or one
set of brushes might be of wire and the other set of bristles, or one set might consist.
of teeth similar to those on a curry comb, while the other consists of bristle or other
brushes. The movement might be reciprocating instead of rotary. Fig. 10 illustrates
a scrubber having three rectangular compartments R clothed internally with bristle or
other brushes, with three flat plungers T'working in them, and clothed externally with
brushes, the three being connected by a cross-head to a rod m which passes out of the
casing through a stuffing-box and is connected by a pitman to a crank m² on a shaft T'.
The vacuum-chamber B and grit-separator C may be omitted in practising my
present invention, and instead of forcing the liquid through the agitators and scrubbers
it may be drawn through by suction. Fig. 11 shows an apparatus wherein the digester
connects directly with the agitator F, and a pump D is connected between the agitator
and the scrubber G, which are in separate casings.
After passing through the agitator and scrubber the pulp may be conducted to any
suitable rinsing and bleaching tanks, to be washed, drained, mixed with bleaching
liquor, and stirred or beaten as may be desired. In Figs. 1 and 2 I have shown them
connected by a pipe D³ to an ordinary rinsing tank or washer H. In this tank the
pulp is beaten by a paddle Q, and caused to circulate around the tank, and the surplus
(water) is drained off at the top by a rotary draining cylinder T. When by the
continual draining off of the water the pulp becomes sufficiently thick, it is drawn off
from the bottom through the pipe Y. It may then go direct to the "wet machine"
be made into sheets of pulp, or it may first be placed in bleaching vats or go to the
"stock chest." It may be rinsed in the tank H by injecting fresh water through
pipe X beneath the perforated false bottom y, and removing this water at the top by
the cylinder T.
22
to
In practical use there will usually be several digesters A, all arranged to discharge
into one vacuum-chamber B, and they will be so operated as to be blown off into the
vacuum-chamber at equal successive intervals, so as to maintain a nearly continuous
operation of the vacuum-chamber, pumps, agitator and scrubber.
The arrangement of the digester relative to the vacuum-chamber is not material.
In Fig. 12 it is shown as mounted over the vacuum-chamber, and a single pump DE
is used both as a vacuum and force pump, being connected by valved pipes both with
the top of the digester and the bottom of the vacuum-chamber, so that it may draw
from either or both at will.
Prior to my invention difficulty has been experienced in effecting a thorough
disintegration of the material in and near the outlet of the digester, the result being
that the portion of the material lying in and near the outlet passage has, at the
termination of the digesting process, been very slightly acted upon. As this is the
portion which is first expelled in blowing off the digester it is liable, when thus
undigested, to clog the outlet, or the nozzle b, and occasion serious difficulty. Hence
it is very important that it shall be digested as thoroughly as the remainder of the
material. This I accomplish by making the valve L a two-way cock, and by supplying
the branch-pipe S2 and its valve 9. The valve L is kept turned toward the pipe S³
during the digestion operation, so that steam, water, or chemicals may at intervals be
injected through the pipe S to act upon this portion of the material.
The digester A is constructed with double-walls, forming a surrounding jacket g.
The inner wall is lined with (or made of) lead, or other material that will resist, the
action of the chemicals. The outer wall is of great strength, sufficient to resist the
internal pressure in the digester. From the upper part of the jacket a pipe g¹ leads
to a chamber a', which is fitted with a water-gage. From this chamber a pipe g²
extends downward to a pump a³, thence through a heater a, and finally enters the

page_text: lower part of the jacket g. Water is admitted to the jacket and pipes through a
pipe g, and the water is kept in circulation by the pump a³. If any leakage occurs
through the inner walls, the matter which passes through is immediately diluted by
the water in the jacket, and is prevented from attacking the metal of the outer wall.
The heater a serves to keep the temperature of the water-jacket up to that within the
digester. The pressure is balanced on both sides of the inner wall, by means of a
pipe which taps the pipe S to the right of the valve 11, thereby communicating with
the interior of the digester. If any fumes accumulate in the chamber a¹ they may be
drawn off through a vacuum tube ƒ which leads to the pipe E¹.
The first part of my invention may be operated with any practicable chemical
process of disintegration such modification of one or the other being made as is
necessary to adapt them to each other. It is especially desirable with the sulphurous-
acid process, which it renders far more speedy, certain and safe than by any previous
method of applying this agent. By my process the fibers are not exposed to the air at
any stage of the treatment, whereby oxidation or discoloration is prevented, the
impurities being all washed out or bleached out before exposure to the air. The
result is that the pulp made by my process is very nearly white, even without bleaching.
By the alternate boiling under pressure and boiling in vacuum the vaporizable
impurities are vaporized and carried off, and the fibers are purified to an extent not
before possible, so far as I am aware. My invention enables paper-pulp to be made
from horse-manure, bedding straw used in stables, and other impure substances the
use of which has heretofore been impracticable or unprofitable.
But the second part of my invention is its most novel and distinctive feature, and
the one to which its value and economy are mainly due. Some attempts have been
made to effect an explosive disruption of the fibers, such as by placing them with
liquid in a closed vessel or "fiber gun," heating them until a high pressure is attained,
and suddenly opening the vessel and permitting its contents to burst out into the
atmosphere. My invention substitutes a slow and uniform discharge into a vacuum
for a sudden discharge into the air, thus rendering the disruptive process practicable.
Any degree of vacuum sufficient to dispose of the fibrous and gaseous matters as fast
as they enter the vacuum-chamber, and thereby avoid the accumulation of a pressure
therein, is of value.
Having now particularly described and ascertained the nature of my said invention
and in what manner the same is to be performed, I declare that what I claim
is the following defined novel features, substantially as hereinbefore described,
namely:-
:-
1. The improvement in the art of disintegrating fibrous substances which consists
in charging them with fluid under pressure and at a high temperature, and forcing them
in a reduced stream into a partial vacuum, whereby the expansion of the fluid when
liberated in the vacuum disrupts the fibers.
2. The improvement in the art of disintegrating fibrous substances which consists
in softening the fibers by digesting them in a closed vessel, charging the softened
fibers with fluid under pressure and at a high temperature, and forcing them through
a contracted nozzle or inlet into a partial vacuum, whereby the expansion of the fluid
when liberated in the vacuum disrupts the fibers.
3. The improvement in the art of disintegrating fibrous substances which consists
in forcing the same with liquid, under heat and pressure, through a contracted nozzle
or inlet, into a vacuum-chamber, condensing the steam therein, and drawing off the
contents of said chamber at a rate sufficient to maintain a partial vacuum therein.
4. The improvement in the art of disintegrating fibrous substances which consists
in boiling them in a suitable vessel under pressure by injecting steam at the bottom
of the vessel, causing it to pass through the mass of material, and escaping the
resulting vapors from the upper part of the vessel through a contracted opening,
whereby a circulation through the mass is maintained under pressure and at a high
temperature, and the vaporizable impurities are dissolved, vaporized and expelled.
5. The improvement in the art of disintegrating fibrous substances which consists

page_text: in boiling them under pressure in a closed vessel, and subsequently introducing steam
at the bottom of the vessel, causing it to pass through the mass of material and escaping
the resulting vapors from the top, whereby the impurities are first dissolved at a
high temperature and are then vaporized and expelled.
6. The improvement in the art of disintegrating fibrous substances which consists
in boiling them in a digester under pressure, drawing off the vapors arising in the
digester while introducing steam to maintain the pressure, and subsequently boiling
in vacuum.
7. The improvement in the art of disintegrating fibrous substances which consists
in boiling them in a digester while circulating steam or liquid through the mass and
from time to time injecting steam into the digester through its outlet, whereby the
material adjacent to the outlet is treated homogeneously with the remaining material.
8. The improvement in the manufacture of paper pulp which consists in first
softening fibrous matter in a digester, then disrupting it by blowing it out under
pressure through a contracted opening, and subsequently precipitating the heavier
particles by flowing with water through a succession of traps.
9. The improvement in the art of making paper pulp which consists in first disin-
tegrating fibrous material and subsequently pulping the disintegrated fibers by
suspending them in a liquid vehicle and agitating the liquid by forcing it through a
passage containing obstructions or deflections, thereby causing a relative movement of
the fibers, whereby the latter are gently worked apart and reduced to a condition of
pulpiness.
10. The improvement in the art of making paper pulp which consists in passing
disintegrated fibers with liquid through an extended passage containing corrugated
plates, whereby it is subdivided into sinuous spaces, through which the liquid Hows,
carrying the fibers against the projecting corrugations.
11. The improvement in the art of making paper pulp which consists in first disin-
tegrating fibrous material by boiling with a solvent, separating the disintegrated fibers
from the solvent, and subsequently pulping them by suspending them in a liquid
vehicle and agitating the liquid by forcing it through a passage containing obstructions,
and simultaneously reciprocating obstructions in said passage by powor, thereby causing
a relative movement of the fibers, whereby the latter are gently worked apart and
reduced to a condition of pulpiness.
12. The improvement in the art of making paper pulp which consists in forcing the
fibers with liquid through a passage or chamber and over moving brushes, which act
to scrub the fibers.
13. The improvement in the art of making paper pulp which consists in forcing
the fibers with liquid through a passage clothed internally with brushes, and scrubbing
them in their passage therethrough by brushes filling said passage and driven by
power.
14. An apparatus for disintegrating fibrous substances, consisting of the combination
of a digester, a vacuum-chamber, an outlet-passage from the digester to said chamber,
a valve in said passage, and an exhausting apparatus connected to said chamber and
adapted to maintain a vacuum therein.
15. The combination of a digester, a vacuum-chamber, an outlet passage from the
digester to said chamber a valve in said passage, and a condenser arranged and adapted
to condense the steam in said chamber.
16. In a pulp-making apparatus, a grit separator for precipitating heavy particles
consisting of a succession of vessels provided with alternate downwardly-projecting
partitions under which the liquid must flow, and dams over which it must flow.
17. An apparatus for disintegrating fibers consisting of a digester, a valved vacuum-
pipe leading from the upper part thereof, an exhausting device connected to said
pipe and adapted to produce a partial vacuum in said digester, and a steam-pipe
entering said digester, combined and adapted to operate substantially as set forth.
18. An apparatus for disintegrating fibers, consisting of a digester, a perforated
pipo or pipes passing through the same, steam, water, and chemical pipes connected
to said perforated pipe, a screen in the bottom of said digester, a drainage pipe

page_text: leading from beneath said screen and connecting with said pipe, and a circulating
pump connected to said drainage pipe and to one end of said perforated pipe and its
discharge-pipe extending to and connected with the opposite end of said perforated
pipe, all combined together and with suitable valves, and adapted to operate
substantially as set forth.
19. The combination of a digester, a vacuum-chamber an outlet-passage from the
digester entering said chamber, a valve in said passage, a force-pump adapted to draw
the liquid from the bottom of said chamber, and a suction-pump adapted to draw the
air from the upper part of said chamber, and thereby to maintain the vacuum therein,
substantially as set forth.
20. A digester constructed with double walls forming a water-jacket between, in
combination with a pipe extending from the top to the bottom of said jacket, and
a pump for causing a circulation in said pipe and jacket, substantially as set forth.
21. The improved apparatus for manufacturing paper pulp consisting of the com-
bination of a digesting vessel, a pump, an agitator consisting of a passage or chamber
containing agitating obstructions or deflections, and pipes connecting the respective
parts, whereby the fibers disintegrated in said digester may be forced by said pump
through said agitator.
22. A pulp-agitator consisting of the combination of a casing with alternate
partitions therein forming a back and forth passage for the pulp, and with agitating
obstructions in said passage adapted to cause an eddying of a stream of liquid forced
there-through.
23. A pulp agitator consisting of the combination of a casing forming a passage
for the pulp, corrugated plates in said casing, the alternate plates being movable
relatively to the others, and mechanism for imparting motion to said alternate
plates.
24. A pulp scrubber consisting of the combination of a casing forming a passage
for the pulp, stationary brushes clothing said passage, and a movable brush arranged
in said passage, whereby the pulp in flowing through passes between said stationary
and movable brushes.
25. A pulp scrubber consisting of the combination of a casing, a cylindrical passage
through said casing, brushes lining said passage, and a cylindrical brush arranged to
rotate in said passage.
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