IMPROVEMENTS IN APPARATUS FOR WASHING AND TREATING PULPS
Year: 1870

page_text: LETTERS PATENT to Alexander Melville Clark, of 53, Chancery Lane,
in the County of Middlesex, Patent Agent, for the Invention of
'IMPROVEMENTS IN APPARATUS FOR WASHING AND TREATING PULPS."―A
communication from abroad by Louis Joseph Amedeć Lespermont,
of 13, Boulevart St. Martin, Paris.
Scaled the 15th September 1870, and dated the 5th April 1870.
PROVISIONAL SPECIFICATION left by the said Alexander Melville
Clark at the Office of the Commissioners of Patents, with his
Petition, on the 5th April 1870.
I, ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the
County of Middlesex, Patent Agent, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN APPARATUS FOR WASHING AND TREATING
PULPS," to be as follows:-
This Invention relates to improvements in apparatus for washing all
kinds of pulp, fecula, or other matters held in suspension in a liquid

page_text: whereby the latter is extracted with the aid of but small quantities
of water, at same time that the washing is rendered as perfect as possible.
In many instances it is desirable to separate the pulpy matter held in
suspension in the liquid used for treating the same without diluting
the said liquid to any extent. This is more particularly the case in the
preparation of pulp for making paper from wood, straw, and other
vegetable substances. These primary matters are disintegrated by the
aid of an alkaline lye in the boiling operation, and the pulp obtained
requires to be separated as free as possible from the alkaline tinctured
liquid, it being also essential to recover the alkaline liquid without the
aid of any large amount of water. In the manufacture of beetroot sugar
also it is necessary to separate the pulp from the saccharine juices it
contains without diluting the same by the addition of any large quantity
Analogous results are also required to be obtained in other
of water.
instances.
The improved continuous acting apparatus of this Invention consists
of a series of sieves of wire gauze for extracting the washing water
from the matters, means being also provided for passing the pulp through
the sieves as also the water used for washing the same.
;'
1 Figures 1, 2, and 3 of the accompanying Drawings illustrate the
détails of one of these improved sieves. A, iron or other metal cage of
truncated conical form forming a frame for the wire gauze by which
the pulp is strained. The smaller end of the sieve is carried by a cap B,
and near its larger end by a cross bar C, both B and C being keyed
on a shaft D. The cap B is provided with two curved tubes E, each
communicating at one end with the interior of B, and open at their
outer ends for taking up the pulp from trough F. A rotary stirrer G
is placed in another part of the trough for mixing the pulp with the
water used for washing the same. The water discharged from the pulp
through the wire gauze cage A falls into a trough I below said cage.
These cages are combined in groups or series varying in number
according to requirement, each apparatus comprising a stirrer, elevator,
and sieve. The sieves may be arranged in various ways; the disposition
shown in Figures 1, 2, and 3 is preferable, where the several sieves may
be mounted on one shaft D, but when the length is limited they may
be disposed on two parallel shafts, as seen in Figure 4. Where the
sieves are required to be of great length, as is necessary with some
pulps from which it is difficult to extract the liquid, each of the sieves

page_text: may be mounted on separate axes, parallel with each other, with the
cap or drum B alternately at opposite ends. The sieves in this case
may be made cylindrical and their axes inclined towards the exit end,
or the sieves may be mounted on horizontal axes and provided with a
screw on the interior, and this arrangement may be substituted with
advantage in some cases for the conical sieves illustrated in the
Drawings.
I will now describe the operation of the machine with reference to
a series of seven sieves as shown in Figure 1. The sieves A to A are
mounted on two parallel shafts D, D', above the troughs I to IV', and
between these are disposed the smaller troughs I to H in which the
stirrers C to C operate, the latter being mounted on shaft M. The
shafts D, D', and M are driven by a shaft N provided with fast and loose
pulleys and toothed gearing O, P, Q, R, S, arranged so as to drive the
shafts D, D', at equal speeds. The pulp to be washed enters at pipe a into
trough II, where it is stirred up by the helical blades C, C, and thence
passes into trough F, where it is taken up by the tubes E of the rotary
sieve A. The pulp is deprived of a portion of the liquid it contains while
in sieve A, such liquid falling into trough I while the strained pulp passes
out at end d into a channel L, from which it is carried by means of
water supplied by a pipe K into the trough II', where it is mixed with
the water by the aid of stirrers C¹, C¹. The mixture then flows into
trough, to be raised by arms E', E', into the sieve A', where the pulp
is separated from the water which falls into the trough I', while the
strained pulp falls into the channel L' and is there supplied by water
from a pipe K', which conveys it into the trough II" to be operated on
by the mixers C", C". The matters then pass into trough F" to be raised
thence by the arms E", E", into sieve A", where it is strained in a similar
manner as described with reference to A, A'. The pulp is discharged
from the sieve A" into channel L", whence it is carried by the water
supplied by pipe K" into trough H, where it is mixed and passes into
trough F, to be raised by arms E" into sieve A. The pulp is then
strained as before, and after passing thence is carried by the water
introduced by pipe K into the troughs II and FW and then up into a
sieve A, whence it is carried by water supplied at K into channel LIV
and trough H into sieve A", then into channel L to which water is
supplied by cock T, is next stirred up in H", and lastly stirred in sieve
A", whence it is supplied in a washed and purified condition to the

page_text: III
channel L and reservoir U. The black arrows in the Drawing,
Figure 1, indicate the course of the pulp from a to U. The washing
water entering at cock T, by which its supply is regulated, mixes with
the pulp escaping from sieve A is separated from it in A", flows from
trough II by the aid of pipe K into trough L, carries the pulp
escaping from A into trough II is separated from the pulp in sieve A",
flows from trough IV by means of pipe Kinto channel L, carries
with it the pulp escaping from A into trough H, is then separated
from the pulp by the sieve A, flows from the trough ITV by pipe K"
into channel L", dilutes the pulp escaping from A", passes thence into
H, F, and then through sieve AI to trough III away by the
pipe K to dilute in L'; the pulp escaping from A' is again mixed with
the pulp at H", enters F", and is raised with the pulp into sieve A",
where it is separated and falls into I". Thence the water passes by
means of pipe K into channel L for diluting the pulp escaping from A,
conducting the latter into H, FI, and then to sieve A', whence it runs
into trough I¹ after passing through the whole series of apparatus.
The passage of the water from T to I' is indicated by the blue arrows.
The water on arriving in reservoir I' after having washed the pulp
passing through the sieves A to AV, being charged with soluble and
other matters contained in the pulp is then pumped out into a reservoir
and used for any purpose required. In sugar making the liquor serves
to steep the beetroot after it has been reduced to pulp, while in the
manufacture of pulp for paper it is passed into the boilers to be again
returned to the sieves by means of pipe a. The liquid separated from
the pulp by sieve A is also available in the manufacture of sugar, while
the alkali is recovered in the paper pulp manufacture by the aid of
furnaces. In the above manner the pulp to be washed entering at a
passes in succession through the whole series of sieves A, being each
time washed by the water which has already operated on the more
perfectly washed pulp, while the washing water entering at T is mixed
successively with the less and less purified pulp and passes out at I',
operating six times where seven sieves are employed, and as many
more times as necessary by increasing the number of sieves. Thus
the washing water and the matters to be operated on are caused to
travel in opposite directions, whereby a uniformly perfect washing is
ensured. · I am aware that cylindrical and conical sieves have been
already used for washing pulp and fecula, but the present improvements
are based on the peculiar combination and disposition of the sieves,

page_text: For example, in paper making, by introducing a solution of chloride of
lime at cock T it will be caused to act on the pulp in a uniform manner.
Thus the pulp arriving at A', is subjected to the action of the weakest
solution, while that escaping from the last of the series of sieves will
be brought in contact with a fresh solution of the full strength and
most favorable for acting on the pulp as a bleaching agent.
5thly. In certain instances the matters to be washed require to be
protected from the action of the air, and this may be ensured by
enclosing the apparatus and filling the space with an inert gas, such
as carbonic acid or steam. This latter may be supplied from an ordinary
generator, or from the waste pipe of a steam engine, or it may be pro-
duced by heating the water (introduced at a and used in the washing)
to a sufficient temperature.
6thly. Brick reservoirs lined with cement will serve in the majority
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Alexander Melville Clark in the Great Seal Patent
Office on the 4th October 1870.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALEXANDER
MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex,
Patent Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by IIer
Letters Patent, bearing date the Fifth day of April, in the year of our
Lord One thousand cight hundred and seventy, in the thirty-third
year of Her reign, did, for Herself, Her heirs and successors, give and
grant unto me, the said Alexander Melville Clark, Her special licence
that I, the said Alexander Melville Clark, my executors, adminis-
trators, and assigns, or such others as I, the said Alexander Melville
Clark, my executors, administrators, and assigns, should at any time
agree with, and no others, from time to time and at all times thereafter
during the term therein expressed, should and lawfully might make,
use, exercise, and vend, within the United Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention for
"IMPROVEMENTS IN APPARATUS POR WASHING AND TREATING PULPS," a com-

page_text: munication to me from abroad by Louis Joseph Amedcé Lespermont,
of 13, Boulevart St. Martin, Paris, upon the condition (amongst others)
that I, the said Alexander Melville Clark, my executors or adminis-
trators, by an instrument in writing under my, or their, or one of
their hands and scals, should particularly describe and ascertain the
nature of the said Invention, and in what manner the same was to be
performed, and cause the same to be filed in the Great Scal Patent Office
within six calendar months next and immediately after the date of the
said Letters Patent.
NOW KNOW YE, that I, the said Alexander Melville Clark, do hereby
declare the nature of the said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement, reference being had to the Sheet of Drawings
hereunto annexed, and to the letters and figures marked thereon (that
is to say) -
This Invention relates to improvements in apparatus for washing all
kinds of pulp, fecula, or other matters held in suspension in a liquid,
whereby the latter is extracted with the aid of but small quantities of
water at same time that the washing is rendered as perfect as possible.
In many instances it is desirable to separate the pulpy matter held in
suspension in a liquid without diluting the said liquid to any great
extent. This is more particularly the case in the preparation of pulp
for making paper from wood, straw, and other vegetable substances.
These primary matters are disintegrated by the aid of an alkaline lye in
the boiling operation, and the pulp obtained requires to be separated as
free as possible from the alkaline tinctured liquid, it being also essential
to recover the alkaline liquid without the aid of any large amount of
water. In the manufacture of beetroot sugar also it is necessary
to separate the pulp from the saccharine juices it contains without
diluting the same by the addition of any large quantity of water.
Analogous results are also required to be obtained in other instances.
The improved continuous acting apparatus of this Invention consists
of a series of sieves of wire gauze for extracting the washing water from
the matters, means being also provided for passing the pulp through the
sieves as also the water used for washing the same.
Figures 1, 2, and 3 of the accompanying Drawings illustrate the
details of one of these improved sieves. A, iron or other metal cage of
truncated conical form, forming a frame for the wire gauze by which

page_text: the pulp is strained. The smaller end of the sieve is carried by a cap B,
and near the larger cnd by a cross bar C, both B and C being keyed on
a shaft D. The cap B is provided with two curved tubes or elevators E,
cach communicating at one end with the interior of B, and open at
their outer ends for taking up the pulp from trough F.
A rotary
stirrer G is placed in another part of the trough for mixing the pulp
with the water used for washing the same. The water discharged from
the pulp through the wire gauze cage A falls into a trough I below
said cage. These cages are combined in groups or series varying in
number according to requirement, cach apparatus comprising a stirrer,
elevator, and sieve. The sieves may be arranged in various ways; the
disposition shown in Figures 1, 2, and 3 is preferable, where the several
sieves may be mounted on one shaft D, but when the length is limited
they may be disposed on two parallel shafts, as seen in Figure 4. Where
the sieves are required to be of great length, as is necessary with some
pulps from which it is difficult to extract the liquid, each of the sieves
may be mounted on separate axes, parallel with each other, with the cap
or drum B alternately at opposite ends. The sieves in this case may be
made cylindrical and their axes inclined towards the exit cnd, or the
sieves may be mounted on horizontal axes and provided with an archi-
nedian screw on the interior, and this arrangement may be substituted
with advantage in some cases for the conical sieves illustrated in the
Drawings.
I will now describe the operation of the machine with reference to
a series of seven sieves, as shown in Figure 4. The sieves A to A are
mounted on two parallel shafts D, D', above the troughs I to II, and
between these are disposed the smaller troughs I to H", in which the
stirrers C to CVI operato, the latter being mounted on shaft M. The
shafts D, D', and M, are driven by a shaft N provided with fast and loose
pulleys and toothed gearing O, P, Q, R, S, arranged so as to drive the
shafts D, D', at equal speeds. The pulp to be washed enters at pipe a
into trough H where it is stirred up by the helical blades C, C, and
thence passes into trough F, where it is taken up by the tubes E of the
rotary sievo A. The pulp is deprived of a portion of the liquid it
contains while in sieve A, such liquid falling into trough I while the
strained pulp passes out at end d into a channel L, from which it is
carried by means of water supplied by a pipe K into the trough H¹,
where it is mixed with the water by the aid of stirrers C¹, C'. The

page_text: mixture then flows into trough F' to be raised by arms E', E', into the
sieve A', where the pulp is separated from the water which falls into the
trough 1 while the strained pulp falls into the channel L, and is there
supplied with water from a pipe K' which conveys it into the trough H"
to be operated on by the mixers C" C". The matters then pass into
trough F to be raised thence by the arms E", E", into sieve A", where
it is strained in a similar manner as described with reference to A, A¹
The pulp is discharged from the sieve A" into channel L", whence it is
carried by the water supplied by pipe K" into trough H™, where it is
mixed and passes into trough F", to be raised by arms E" into
sieve A. The pulp is then strained as before, and after passing thence
is carried by the water introduced by pipe K into the troughs H
and F, and then up into a sieve A, whence it is carried by water
supplied at K into channel L" and trough II" into sieve A", then into
channel L, to which water is supplied by cock T, is next stirred up
in H, and lastly stirred in sieve A", whence it is supplied in a washed
and purified condition to the channel L" and reservoir U. The black
arrows in the Drawing, Figure 4, indicate the course of the pulp from a
to U. The washing water entering at cock T, by which its supply is
regulated, mixes with the pulp escaping from sieve AV, is separated from
it in A, flows from trough 1 by the aid of pipe K into trough L,
carries the pulp escaping from A" into trough H, is separated from the
pulp in sieve A", flows from trough I by means of pipe K into
channel L, carries with it the pulp escaping from A into trough H",
is then separated from the pulp by the sieve A", flows from the trough I'v
by pipe K into channel L", dilutes the pulp escaping from A",
passes thence into H, F, and then through sieve AI to trough I"
away by the pipe K' to dilute in L' the pulp escaping from A', is again
mixed with the pulp at H", enters F", and is raised with the pulp into
sieve A, where it is separated and falls into I". Thence the water
passes by means of pipe K into channel L for diluting the pulp escaping
from A, conducting the latter into H', F', and then to sieve A', whence it
runs into trough I' after passing through the whole series of apparatus.
The passage of the water from T to I' is indicated by the blue arrows.
The water on arriving in reservoir I', after having washed the pulp
passing through the sieves A to A", being charged with soluble and other
matters contained in the pulp is then pumped out into a resevoir and
used for any purpose required. In sugar making the liquor serves to

page_text: steep the beetroot after it has been reduced to pulp, while in the
manufacture of pulp for paper it is passed into the boiler to be again
returned to the sieves by means of pipe a. The liquid separated from
the beetroot pulp by sieve A is also available for concentration in the
manufacture of sugar, while the alkali contained in the washing liquid
similarly separated in the paper pulp manufacture is revivified by the
aid of furnaces. In the above manner the pulp to be washed entering
at a passes in succession through the whole series of sieves A, being
each time washed by the water which has already operated on the morc
perfectly washed pulp, while the washing water entering at T is mixed
successively with the less and less purified pulp and passes out at I',
operating six times where seven sieves are employed, and as many more
times as necessary by incrcasing the number of sieves. Thus the
washing water and the matters to be operated on are caused to travel
in opposite directions, whereby a uniformly perfect washing is ensured.
I am aware that cylindrical and conical sieves have been already used
for washing pulp and fecula, but the present improvements are based on
the peculiar combination and disposition of the sieves, whereby the
water and matters are caused to travel in opposite directions, this result
being ensured by the aid of tubes E, E', although these latter may be
replaced by any other suitable clevating apparatus, such as bucket
chains or pumps. It is, however, preferable to employ the arrangement
shown on account of its simplicity and easy action. The framing of
the sieves A, A', A", Figures 1, 2, and 3, are shown as made of angle
iron rivetted and bolted together so as to form shells, which may be
readily disconnected for renewing the wire gauze covering. They may,
however, be made of sheet iron, zinc, or copper, and perforated. The
troughs H, F, I, L, II', F', I', L', are constructed of brickwork lined
with cement. The successive mixings of the pulp and water used for
washing the same is shown in Figures 1 and 3 as being effected by a
stirrer G, while in Figure 4 a series of arms C, C¹, C", are used. The
mixing may however be otherwise operated.
In the manufacture of pulp for paper the reservoir U receiving the
purified pulp would be provided with a stirrer for diluting it in the
water supplied at V to channel L". The pulp thus diluted is then
supplied by means of a pump or pulp engine to the beaters or bleachers,
or to a reservoir for supplying such machines.

page_text: The apparatus is equally applicable for treating beetroot whether
rasped or subdivided.
It is also applicable for the treatment of pulp obtained from vegetable
matters, and for washing wood reduced to pulp by the aid of an
alkali.
I would further remark,-
1st. That the water may be introduced either hot or cold, according
to the nature of the material under treatment.
2ndly. When the matters contain sand, which it is desirable to separate,
the water flowing from the wire sieves is passed through fine gratings
at bottom of troughs disposed between troughs I, I, I", and F, FI, F".
3rdly. The apparatus may be used in the manufacture of paper, not
only for separating the alkaline liquors resulting from the treatment of
the vegetable matters with soda, but also for washing the bleached pulp
and removing the chlorine and acids contained, in which case a
considerably less quantity of water is required than in the machines
now used.
4thly. I may also by means of the same apparatus ensure a uniform
action of the chemical agents on the matters in suspension in the water.
For example, in paper making, by introducing a solution of chloride of
lime at cock T it will be caused to act on the pulp in a uniform manner.
Thus the pulp arriving at A' is subjected to the action of the weakest
solution, while that escaping from the last of the series of sieves will
be brought in contact with a fresh solution of the full strength and
most favourable for acting on the pulp as a bleaching agent.
5thly. In certain instances the matters to be washed require to be
protected from the action of the air, and this may be ensured by
enclosing the apparatus and filling the space with an inert gas, such as
carbonic acid or with steam. This latter may be supplied from an
ordinary generator, or from the waste pipe of a steam engine, or it may
be produced by heating the water (introduced at a and used in the
washing) to a sufficient temperature.
6thly. Brick reservoirs lined with cement will serve in the majority
of cases, but for washing beetroot pulp they would be made of metal.
Having described the nature of the Invention, and the manner of
performing the same, I declare that what I claim as the Invention to be

page_text: protected by the herein-before in part recited Letters Patent is, the
improved continuous acting apparatus for washing pulps constructed
and operating substantially as herein-before described and illustrated in
the Drawings annexed.
In witness whereof, I, the said Alexander Melville Clark, have
hereunto set my hand and seal, this Fourth day of October,
in the year of our Lord One thousand eight hundred and seventy.
Witness,
W*. CLARK,
53, Chancery Lanc.
A. M. CLARK. (L.S.)