Improvements in Settling and Recovering Apparatus for Paper and Pulp Manufacture.
Year: 1898

page_text: Date of Application, 1st Mar., 1898
Complete Specification Left, 16th Apr., 1898-Accepted, 20th May, 1898
PROVISIONAL SPECIFICATION.
Improvements in Settling and Recovering Apparatus for Paper and
Pulp Manufacture.
I, WARREN CURTIS, residing at No. 368, Palmer Street, Palmer, in the State
of New York, United States of America, Manufacturer, do hereby declare the
nature of the said invention to be as follows:-
Waste water from paper and pulp mills contains fibre and often clay and other
heavy materials which flow away with such fibre and are lost, and in addition
to this, streams are often polluted by the waste from the paper mill, and in some
countries stringent laws exist to prevent such refuse being run into the streams.
The present improvement ensures the detention in a vat of all solid substances,
and not only saves such substances and makes them subsequently useful, but it
also prevents the pollution of streams, because the water passing out from the
improved apparatus is substantially pure.
In the present improvement, the waste water, from which materials held in
suspension are to be separated, is run into a tank in such a way as to avoid
agitation and the water passes down below baffle boards and is finally allowed to
run away at or near the surface of the liquid, and the water passing down below
the baffle boards causes the heavier materials to remain at or near the bottom,
while the water rises and passes away and the heavier materials continue to
subside to the bottom of the tank, and in the bottom, receptacles are provided
connecting with delivery pipes at the bottom, and scrapers are moved along
gradually to carry the heavier materials to the receptacles without agitating the
water.
Where the paper mill is so situated that there is ample ground room, the tank
extends in a horizontal direction and is of considerable length, and the water is
of a comparatively small depth, but where the space is restricted, the tank is
advantageously circular and of a sufficient diameter and height to adapt the
apparatus to the volume of water passing through the same. In either instance
the water passes below a straight or cylindrical baffle board before it rises to the
place of discharge, and scrapers act upon the bottom of the tank to move the
solid materials to the place of delivery.
Where the tank is circular the scrapers are moved by a central shaft; where
the tank is oblong and extended horizontally the scrapers are connected with
chains passing over sprocket wheels, so that they are moved gradually.
In either instance the receptacles in the bottom of the tank are hopper-shaped,
and provided with discharge pipes slotted upon their upper sides for the solid
materials to pass through such slots into the pipes from the hopper-shaped
receptacles, and agitators are employed for preventing the pipes becoming
clogged by the solid materials, such agitators being in the form of rods with
fingers, the rods passing through stuffing-boxes at the ends of the pipes.

page_text: The discharge pipes are usually connected near the ends of the pipes leading
from the hoppers by elbows or T's, and such discharge pipes lead to a pump
preferably a centrifugal rotary pump that elevates the water and solid materials
into a storage vat, from which such materials are allowed to flow to the paper
making machinery, thereby saving such solid materials and utilizing the same.
In the storage tank there is advantageously a float acting upon a valve in the
pipe that leads from the centrifugal pump, so that the materials may be taken
to the storage tank only as rapidly as the materials are removed from such storage
tank, the level of the liquid in the storage tank being maintained by the float
and valve in the pipe leading to the centrifugal pump.
In the long cylindrical tank it is advantageous to make use of hanging aprons
upon the bottom edges of the lower baffle boards, and these aprons yield to the
scrapers as they are moved along, and by falling back into position they close the
openings between the bottom edges of the lower baffle boards and the bottom of
the tank, so as to compel the gradual flow of the water up and over the lower
baffle boards, as such water and materials gradually pass from the supply end to
the delivery end of the settling tank.
1000
BREWER & SON,
London & Leeds, Agents for the Applicant.
Improvements in Settling and Recovering Apparatus for Paper and
Pulp Manufacture.
I, WARREN CURTIS, residing at No. 368, Palmer Street, Palmer, in the State
of New York, United States of America, Manufacturer, 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: -
Waste water from paper and pulp mills contains fibre and often clay and other
heavy materials which flow away with such fibre and are lost, and in addition
to this, streams are often polluted by the waste from the paper mill, and in some
countries stringent laws exist to prevent such refuse being run into the streams.
The present improvement ensures the detention in a vat of all solid substances,
and not only saves such substances and makes them subsequently useful, but it
also prevents the pollution of streams, because the water passing out from the
improved apparatus is substantially pure.
In the present improvement the waste water from which materials held in
suspension are to be separated, is run into a tank in such a way as to avoid
agitation and the water passes down below baffle boards and is finally allowed to
run away at or near the surface of the liquid, and the water passing down below
the baffle boards causes the heavier materials to remain at or near the bottom,
while the water rises and passes away and the heavier materials continue to
subside to the bottom of the tank, and in the bottom, receptacles are provided
connecting with delivery pipes at the bottom, and scrapers are moved along
gradually to carry the heavier materials to the receptacles without agitating the
water.
Where the paper mill is so situated that there is ample ground room, the tank
extends in a horizontal direction and is of considerable length, and the water is
of a comparatively small depth, but where the space is restricted, the tank is
advantageously circular and of a sufficient diameter and height to adapt the
apparatus to the volume of water passing through the same. In either instance
'the water passes below a straight or cylindrical baffle board before it rises to the

page_text: place of discharge, and scrapers act upon the bottom of the tank to move the
solid materials to the place of delivery.
Where the tank is circular the scrapers are moved by a central shaft; where
the tank is oblong and extended horizontally the scrapers are connected with
chains passing over sprocket wheels, so that they are moved gradually.
In either instance the receptacles in the bottom of the tank are hopper-shaped
and provided with discharge pipes slotted upon their upper sides for the solid
materials to pass through such slots into the pipes from the hopper-shaped
receptacles, and agitators are employed for preventing the pipes becoming
clogged by the solid materials, such agitators being in the form of rods with
fingers, the rods passing through stuffing-boxes at the ends of the pipes.
The discharge pipes are usually connected near the ends of the pipes leading
from the hoppers by elbows or T's, and such discharge pipes lead to a pump
preferably a centrifugal rotary pump that elevates the water and solid materials
into a storage vat, from which such materials are allowed to flow to the paper
making machinery, thereby saving such solid materials and utilizing the same.
In the storage tank there is advantageously a float acting upon a valve in the
pipe that leads from the centrifugal pump, so that the materials may be taken
to the storage tank only as rapidly as the materials are removed from such storage
tank, the level of the liquid in the storage tank being maintained by the float
and valve in the pipe leading to the centrifugal pump.
In the long cylindrical tank it is advantageous to make use of hanging aprons
upon the bottom edges of the lower baffle boards, and these aprons yield to the
scrapers as they are moved along, and by falling back into position they close the
openings between the bottom edges of the lower baffle boards and the bottom of
the tank, so as to compel the gradual flow of the water up and over the lower
baffle boards, as such water and materials gradually pass from the supply end to
the delivery end of the settling tank.
In the drawing, Figure 1 is a longitudinal section and Fig.
a plan view
ilustrating the present improvement as applied to a horizontal tank. Fig. 3
is an end view partly in section. Fig. 4 a section on a larger scale of the delivery
hopper. Fig. 5 is a section of the storage vessel. Fig. 6 is a vertical section of
the apparatus in the circular form. Fig. 7 is a sectional plan view at the line 17
of Fig. 6, and Fig. 8 is a cross section in larger size of the hopper in the bottom
of the tank.
The tank is to be of any desired size so as to hold sufficient water in proportion
to the gradual supply and discharge, and this tank may be of any desired
material.
I have represented the same in Figs. 1, 2 and 3 as having sides A, and bottom B
supported by frames C at suitable intervals, and the inlet pipe D brings the
materials to the weir E from which said materials flow in a uniform layer over
the dam 4 and pass down gradually into the liquid in the tank and the overflow
weir F is to be slightly below the level of the dam 4, so that there will be but
little descent or plunge of the water from the dam 4 into the water in the tank,
and the overflow weir F connects with the delivery pipe G which leads the waste
water to the desired place of discharge. Across the tank are baffle boards H
and K, the boards K extending from above the water line to one-half or two-
thirds of the depth of the water, and the baffle boards H extend up from the
bottom from one-half to two-thirds of the depth of the water; but these baffle
boards H do not extend down to the bottom B of the tank, there being aprons I
of rubber or other suitable material fastened at their upper edges at one side of
the baffle boards and resting at their bottom edges against the bottom of the tank.
These aprons allow for the passage of the scrapers hereafter referred to.
In the bottom B of the tank are transverse hoppers L shown in larger size in
the cross section Fig. 4. The hoppers are open across the bottom of the tank as
seen in Fig. 2, and inclined boards at the bottoms of the hoppers fit closely against
the pipe M that has a longitudinal slot in the top thereof, and the materials that

page_text: subside from the water are gradually moved or scraped along upon the bottom B
of the tank to these transverse hoppers; and with this object in view, the slats N
are connected to the endless chains that pass around the guide pulleys P and
a slow movement is given to the guide pulleys P preferably by a gear wheel Q and
a worm pinion R, see Figs. 2 and 3, that is revolved with regularity and at the
desired speed by competent power; and by this arrangement the endless link belt
or chain is moved at the proper speed and preferably with the scrapers, that run
upon the bottom, going in a direction opposite to the gradual flow of the water,
so that the materials, as they subside, are carried to the transverse hoppers
without agitating the water in the tank.
The hanging aprons I are notched where the link belts or endless chains O pass,
and such aprons yield to the passing slats or scrapers and drop back so as to
prevent the current of water passing under the baffle boards H.
It is advantageous to provide a rod S with a hooked end within the pipe at the
bottom of each of the transverse hoppers, such rod coming out through a suitable
opening or stuffing box at the otherwise closed end of such pipe, for the purpose of
agitating the materials that may have subsided in the bottom of the transverse
hopper, and for clearing the slot in the pipe M so that the materials may flow
into the pipe T that passes from the end of the transverse hopper to a longitudinal
pipe T leading to a pump U by which the materials are carried up to the storage
vessel V.
A pipe W leads to the beater or mixing engine and the discharge is regulated
by the cock 6 and there is a valve in the rising delivery pipe 8 and a lever and
float 9 to such valve 7 so as to regulate the quantity of material discharged by
the pump into the storage tank, because it is desirable not to pump up into such
storage tank V the materials from the tank A B any more rapidly than necessary,
thereby allowing as much time as possible for the solid materials to subside in
such tank A B. It is generally advantageous to employ a centrifugal pump U
as the materials are not liable to clog in the same.
It is to be understood that the number of transverse hoppers may be varied
according to the size of the apparatus, and that the operations performed are
gradual and continuous so that as much saving may be effected as may prove
economical; and the materials thus saved are returned with regularity into the
beater or mixing engine so as to ensure uniformity in the paper product.
The cocks or valves at U serve to regulate the quantity of material drawn off
from each hopper, so that there will not be more accumulation in one hopper than
in another.
The flow of materials from the storage vessel is regulated according to the
requirements of the mixing engines, as the less quantity drawn from the settling
tank, the better, because of being more concentrated and valuable, and the
materials drawn from the storage vessel are available instead of fresh water.
In practice it is found that the pulp fibre is injured by fermentation if allowed
to remain for a day or two for settling; by the present improvement, the operations
being progressive and continuous, the pulp is saved and returned to the engine
as quickly as possible and in its original fresh condition.
The inlet opening or weir or dam may be at any desired level, there being
advantageously a box E into which the pipe D opens so that the supply may be
spread with uniformity into the tank. If desired, the storage tank V may be
dispensed with, and the pipe 8 from the pump U may lead direct to the beating
or mixing engine. The scrapers can be moved in either direction.
In the circular form represented in Figs. 6 and 7, the same letters of reference
are employed to the parts that correspond with those shown in Figs. 1 and 2, the
differences being that the tank A is circular and the baffle boards are in the form
of a cylinder that compels the material that is supplied by the pipe D to pass
down below the baffle cylinder H before rising and flowing in a thin stream over
the top edge or dam F into the annular trough from which the water passes by
the pipe G, and it is advantageous to employ a distribution plate E within the

page_text: Dame cynnder H for preventing agitation by the water running in through the
pipe D.
The scrapers N are connected to the vertical shaft O' by which they are
revolved gradually. This shaft O¹ is driven by a suitable gearing at P2 and a
belt pulley P The hoppers L are advantageously radial and open into the
pipes M that lead by the pipes T T to the centrifugal pump U and pipe 8 by
which the materials are discharged into the storage vessel V and the rod S in the
pipe M can be reciprocated to agitate the material in the bottom of the hopper and
in the pipe M to prevent the parts becoming clogged.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is:-
First: The combination in a settling tank of a supply pipe for leading water
and solid materials into the tank, a baffle board or cylinder beneath which the
materials pass, an overflow edge or dam for the escape water, hoppers in the
bottom of the tank, and discharge pipes leading therefrom and scrapers acting at
or near the bottom of the tank for moving the solid materials to the hoppers, sub-
stantially as set forth.
Second: The combination in a settling tank of a supply at one end and a
discharge at the other end near the level of the water, baffle boards or a cylinder
between the supply and the discharge and beneath which the materials pass,
hoppers in the bottom of the tank for receiving the heavier materials, pipes through
which such heavier materials are discharged, means for moving the heavier
materials gradually along the bottom of the tank to the hoppers, a storage tank,
pipes and a pump for transferring the materials from the settling tank and to
the storage vessel, substantially as set forth.
Third: The combination in a settling tank, of a supply at one end and a
discharge at the other end near the level of the water, baffle boards or a cylinder
between the supply and the discharge and beneath which the materials pass,
hoppers in the bottom of the tank for receiving the heavier materials, pipes through
which such heavier materials are discharged, means for moving the heavier
materials gradually along the bottom of the tank to the hoppers, a storage tank,
pipes and a pump for transferring the materials from the settling tank to the
storage vessel and a valve and float for regulating the discharge of the materials
into the storage vessel, substantially as set forth.
Fourth: The combination with the settling tank, of scrapers and means for
moving the same upon the bottom of the tank, baffle boards sufficiently high above
the bottom of the tank for the scrapers to pass below them and means for con-
veying away the material from the bottom of the tank, substantially as set forth.
Fifth The combination with the settling tank, of scrapers and means for
moving the same on the bottom of the tank, baffle boards sufficiently high above
the bottom of the tank for the scrapers to pass below them, and aprons hanging
between the lower portions of the baffle boards and the bottom of the settling tank
and yielding as the scrapers pass along, and receptacles for the solid materials
acted upon by the scrapers, substantially as set forth.
Sixth The settling tank having hoppers in the bottom and delivery pipes in
combination with scrapers and mechanism for moving the same gradually, and
agitators in the delivery pipes of the hoppers, substantially as set forth.
Seventh-The combination with the settling tank and a supply pipe of baffle
boards or a cylinder beneath which the water and heavier materials pass, and a
dam at the level of the water and over which the water passes in a thin layer
and a trough and pipe for conveying away such water, substantially as set forth.
Eighth The combination with the settling tank, of hoppers or receptacles in
the bottom, scrapers for moving the solid materials to the hoppers, discharge
pipes at the bottom of the hoppers, a storage vessel, pipes leading to the same, a
centrifugal pump for passing the water and solid materials to the storage vessel,

page_text: and a float and valve for regulating the discharge of such materials, substantially
as set forth.
Dated this 16th day of April 1898.
BREWER & SON,
London & Leeds, Agents for the Applicant.