IMPROVEMENTS IN TREATING SPENT OR USED LEYS RESULTING FROM THE PREPARATION OF FIBROUS SUB- STANCES USED IN THE MANUFACTURE OF PAPER STock
Year: 1865

page_text: LETTERS PATENT to Thomas Routledge, of the Ford Works Company
i (Limited), Sunderland, for the Invention of "IMPROVEMENTS IN TREATING
SPENT OR USED LEYS RESULTING FROM THE PREPARATION OF FIBROUS SUB-
STANCES USED IN THE MANUFACTURE OF PAPER STock."
Sealed the 25th July 1865, and dated the 2nd February 1865.
PROVISIONAL SPECIFICATION left by the said Thomas Routledge at the
Office of the Commissioners of Patents, with his Petition, on the
2nd February 1865. :
I, THOMAS ROUTLEDGE, of the Ford Works Company (Limited), Sunder-
land, do hereby declare the nature of the said Invention for "IMPROVEMENTS
IN TREATING SPENT. OR USED LEYS RESULTING FROM THE PREPARATION OF FIBROUS
SUBSTANCES USED IN THE MANUFACTURE OF PAPER STOCK," to be as follows:-
My Invention consists in the economic evaporation of the spent leys or
waste liquors resulting from the treatment of fibrous materials in the manu-
facture of paper and half stuff, or paper stock, and the subsequent recovery
of the alkali therefrom.
In the manufacture of paper it is necessary before the rags or other fibrous
materials employed can be reduced to a condition suitable to be converted
into,paper stock or bleached, to subject them to a process of boiling in alkaline
leys more or less active, proportioned to the strength of the material to be
treated, and the amount of foreign or extraneous matter which all paper-
making material holds more or less in combination.

page_text: For rags, especially of the higher class, the leys are comparatively speaking
mild, for material of the character of flax and hemp jute more active treat-
ment is necessary, but raw fibrous materials of such nature as esparto or alfa,
and straw, demand very energetic treatment in order to reduce the silica,
gluten, gum, resin, coloring and other matters combined more or less with all
raw vegetable fibres in their normal condition into a soluble form, when such
matters may readily be removed by a subsequent rinsing or washing, and
then the ultimate fibrous residue comminuted into paper stock, and bleached
if desired.
Although lime alone is sometimes employed for brown or other low
quality paper, the leys above referred to are generally composed of soda
in the form of carbonate or hydrate, or both, the alkaline salt thus employed is
dissolved, and necessarily diffused in a large quantity of water, and during the
boiling process the said leys are still further diluted by the condensation of
the steam usually employed for this purpose. When the boiling process is
concluded the spent leys are run away to waste, they still however contain in
solution the greater portion of the soda or other alkaline salt employed, and also
retaininintimatechemical combination thegummo-resinouscoloring, andother
matters eliminated or extracted from the fibres in the boiling process, the
liquor consequently is very highly colored, and a soapy compound being also
formed, it follows that when the said liquors are run into the river or stream
near which from the nature of the trade a paper mill must necessarily be
situated, very considerable fouling or contamination thereof results, and as
this so called "pollution of streams" has lately attracted considerable public
attention, should legislative interference as would appear probable ensue,
much embarassment would be entailed on the paper trade.
From the increased employment of esparto or alfa, and straw, which
owing to the cotton famine and extension of the paper trade since the remis-
sion of the duty, is likely still further to be extended, it is highly desirable that
some simple, economical, and convenient method should be employed not
merely to prevent this contamination of streams, but to recover the alkali
hitherto wasted, which in moneyvalue amounts in round figures to from 20s.
to 50s. for each ton of material, such as esparto and straw, operated upon.
As herein-before remarked the spent leys are very dilute, the ordinary pro
cess therefore of evaporation in long shallow pans, or in reverberatoryfurnaces,
presents many difficulties to a paper manufacturer, not only on account of the
large extent of surface area which would be required (and which in very few
mills would be available), but on account of the cost of erection, wear, and
tear, and labor attendant on plant of such a character, a preliminary or

page_text: intermediate process for concentrating the spent leys becomes therefore a
question of primary importance.
I now proceed to describe the nature of my Invention (having for its object
the preliminary concentration prior to final evaporation of the aforesaid spent
leys),and its application as follows:-I convey the spent leys from the boiling
pans after that process is concluded, through pipes bygravitations if possible to
some convenient portion of the works or mill into a suitable vessel or vessels,
which should by preference be of iron, but other material may be employed,
which vessel or vessels may be placed over or in connection with someflue, or
where spare heat is available in order to retain the normal temperature of the
spent leys as run from the boiling pans, or the said leys inay be conducted
into a closed boiler or other vessel, either revolving or stationary, or theliquor
agitated therein, such boiler or other vessel being connected with a furnace,
and the steam arising from the evaporation of the spent leys in such boiler or
other vessel utilized as a source of heat or otherwise; the aforesaid furnace
may also be connected with and furnish the heat for the apparatus herein-
after described, which should be placed as near as may be to the boiler or
other vessel in question.
The apparatus referred to consist of a tower or other suitable arrangement
constructed of bricks, stone, or iron plates suitably supported, the external
form of which must be governed by convenience, according to the nature of
the situation; it may, for example, consist of a vertical tower from 20 to 30
feet in height, oblong in shape, say 4 feet wide and 6 feet long, and inside
such tower I adapt or fix shelves or partitions of iron or other suitable
material (which may be corrugated to expose greater surface) placed at such
an inclination that liquor will flow down the same; the upper one of these
shelves is attached to one end and to both sides of the tower, but does not
extend to the other end thereof, leaving an open space of from 4 to 6 inches;
the next shelf or partition is placed below this, and is attached to the opposite
end of the tower, about 4 inches below the lower end of the shelf above,and.
to the two sides of the tower it is placed at a similar inclination, but does not
extend to the other end of the tower, leaving as before a similar space of from
4 to 6 inches, and all the other shelves or partitions are similarly arranged, a
supply of liquor being introduced on the upper part of the first shelf flows
down from it to the next, and so on from shelf to shelf in thin films or sheets,
which may be regulated at will, and in its downward transit is exposed to an
upward current of air introduced to the lower portion of and drawn through
the tower by means of a chimney draft, fan, blast, suction, or other convenient
method.

page_text: The tower may also have adapted to it at or near its lower part a furnace
or other apparatus of any well known construction suitable for the production
of a supply of heated air, which may be drawn up or forced through the
tower by the aforesaid chimney draft, fan, blast, suction, or other convenient
method, or the said current of heated air may be obtained from the furnace
attached to the boiler or other vessel for receiving the spent leys from the
boiling pans before referred to.
The tower may also, instead of being fitted with the shelves or partitions, as
above described, be furnished with layers or strata of broken stone, flints,
pottery, coke, or other suitable material through which the spent leys forced
or pumped up to the top of said tower may flow or trickle, exposed to the
upward current of air, heated or otherwise, as before mentioned, or like
towers may be employed in which the leys are caused otherwise to descendin
showers or in minute divisions, meeting the upward current of air.
And, further, should the situation of the works admit of such an arrange-
ment from being placed near elevated ground on which a chimney can be
convenientlyerected,an inclined chamber or shoot constructed as the tower of
brick, stone, iron, or other suitable material may be carried upwards any con-
venient distance, furnished with shelves,corrugations, or ribs of irou or other
suitable material,down which the liquor previously forced or pumped up to
the top thereof may flow,meeting an upward current of air, heated or other-
wise created by the said chimney draft,such current of air being kept down
to the surface of the descending liquor in a thin stratum from 4 to 6 inches,
and the said inclined chamber may be constructed of any convenient width.
As the spent leys or liquor flows down the tower or other arrangement they
are collected at the bottom thereof, and thence conveyed to the first receiving
boiler or vessel, or to another vessel, again heated,and again forced up to the
top of the tower, and so on until the liquor is sufficiently concentrated, or the
liquor may be cooled down and any crystallisable salts fished out; the liquor
may finally be run into a reverberatoryor boiling-down furnace of theordinary
character employed for the manufacture of soda, there evaporated to dryness
when the vegetable and resinous compounds retained in the leys will ignite,
giving out gaseous products, which may be utilised as a source of heat, or
when reduced to a pasty mass drawn from the reverberatory or otherfurnace,
and placed in a retort or still, and the said gaseous products collected for
illuminating purposes. The resulting ash may then be lixiviated in the
ordinary manner, and the soda or other alkaline salts obtained therefrom as
practised with soda ash liquors or fresh leys for the process of boiling the
fibres obtained by boiling the resulting ash in water, adding sufficient limein

page_text: the caustic state to deprive it of its carbonic acid, and the clear ley drawn off
for use in the usual manner.
In the ordinary process of treating fibrous material for paper stock when
hydrate or caustic soda is not employed for making the leys, soda ash, or soda
in the state of carbonate is employed, which is dissolved in water, and the
proper equivalent proportion of caustic or quicklime added thereto, the whole
boiled up together, and the resulting clear ley after settling, decanted or
syphoned off for use, leaving the lime in the state of carbonate as a mud in
the bottom of the pan or other vessel in which the ley is made.. This lime
mud contains both mechanically and chemically combined there with a con-
siderable per-centage of alkali, which I propose to regain by first carefully
washing or filtering the lime mud, adding such liquor to the water used for
making the fresh leys, and then running the said lime mud into shallow pans
or vessels made of iron, brick, or other suitable material, the said pans being
heated by the waste heat from any of the previous processes or otherwise to
abstract the excess of water therefrom, when the lime may be converted into
bricks or lumps, and again burnt, and the carbonic acid driven off, and thus
converted again into caustic or quick lime, retaining the alkali combined
therewith, and the said lime like the alkali reclaimed from the spent leys,
used again and again in making fresh leys; or it may be added to the soda or
other alkali in the boiling down or calcining furnace, by this means avoiding
to a great extent the cost of purchasing fresh lime, and also a fruitful source
of contamination of the stream.now caused by running therein the lime dregs
from the ley-making process.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Thomas Routledge in the Great Seal Patent Office on the
2nd August 1865.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
ROUTLEDGE, of the Ford Works Company (Limited), Sunderland, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Second day of February, in the year of our Lord
One thousand eight hundred and sixty-five, in the twenty-eighth year of
Her reign, did, for Herself, Her heirs and successors, give and grant
unto me, the said Thomas Routledge, Her special licence that [, the said
Thomas Routledge, my executors, administrators, and assigns, or such others

page_text: as I, the said Thomas Routledge, 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 law-
fully 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 TREATING SPENT OR USED LEYS RESULTING
FROM THE PREPARATION OF FIBROUS SUBSTANCES USED IN THE MANUFACTURE OF
PAPER STOCK," upon the condition (amongst others) that I, the said Thomas
Routledge,my executors or administrators, by an instrument inwriting under
my, or their, or one of their hands and seals, 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 Seal Patent
Office within six calendar months next and immediately after the date of the
said Letters Patent.
NOW KNOW YE, that I, the said Thomas Routledge, 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 thereof, that is to say:-
My Invention consists in the economic evaporation of the spent leys or
waste liquors resulting from the treatment of fibrous materials in the manu-
facture of paper and half stuff or paper stock, and the subsequent recovery of
the alkali therefrom.
In the manufacture of paper, it is necessary, before the rags or other fibrous
materials employed can be reduced to a condition suitable to be converted
into paper stock or bleached, to subject them to a process of boiling in
alkaline leys more or less active, proportioned to the strength of the material
to be treated and the amount of foreign or extraneous matter which all paper-
making material holds more or less in combination.
For rags, especially of the higher class, the leys are, comparatively
speaking, mild; for material of the character of flax, hemp, and jute, more
active treatment is necessary, but raw fibrous materials of such nature as
esparto or alfa,and straw,demand very euergetic treatment in order to reduce
the silica, gluten, guin, resin, coloring and other matters, combined more or
less with all raw vegetable fibres in their normal condition, into a soluble form,
when such matters may readily be removed by a subsequent rinsing or
washing, and then the ultimate fibrous residue comminuted into paper stock,
and bleached if desired.
Although lime alone is sometimes employed for brown or other low quality
paper, the leys above referred to are generally composed of soda in the form

page_text: of carbonate or hydrate, or both. The alkaline salt thus employed is dissolved
and necessarily diffused in a large quantity of water, and during the boiling
process the said leys are still further diluted by the condensation of the steam
usually employed for this purpose. When the boiling process is concluded
the spent lays are run away to waste; they still, however, contain in solution
the greater portion of the soda or other alkaline salt employed, and also retain
an intimate chemical combination the gummo-resinous, coloring, and other
matters eleminated or extracted from the fibres in the boiling process; the
liquor consequently is very highly colored, and a soapy compound being also
formed, it follows that when the said liquors are run into the river or stream
near which, from the nature of the trade a paper mill must necessarily be
situated, very considerable fouling or contamination thereof results, and as
this so called pollution of streams' has lately attracted considerable public
attention, should legislativeinterference as would appear probable ensue,much
embarrassment would be entailed on the paper trade.
From the increased employment of esparto or alfa, and straw which, owing
to the cotton famine and extensiou of the paper trade since the remission of
the duty, is likely still further to be extended, it is highly desirable that some
simple,economical, and convenient method should be employed, not merely to
prevent this contamination of streams, but to recover the alkali hitherto
wasted, which in money value amounts in round figures to from 20)/ to.50/
for each ton of material, such as esparto and straw operated upon. As
herein before remarked, the spent leys are very dilute; the ordinary process,
therefore, of evaporation in long shallow pans or in reverberatory furnaces
presents many difficulties to a paper manufacturer, not only on account of the
large extent of surface area which would be required (and which in very
few
mills would be available,) but on account of the cost of erection, wear and
tear and labour attendant on plant of such a character; a preliminary or
intermediate process for concentrating the spent leys becomes therefore a
question of primary importance.
I now proceed to describe the nature of my Invention (having for its object
the preliminary concentration prior to final evaporation of the aforesaid spent
leys) and its application, as follows:-I convey the spent leys from the boiling
pans after that process is concluded through pipes, by gravitation if possible,
to some convenient portion of the works or mill into a suitable vessel or
vessels, which should by preference be of iron, but other material may be
employed, which vessel or vessels may be placed over or in connection with
some flue, or where spare heat is available, in order to retain the normal
temperature of the spent leys as run from, the boiling pans, or the said leys

page_text: may be conducted into a closed boiler or other vessel either revolving or
stationary, or the liquor agitated therein, such boiler or other vessel being
connected with a furnace, and the steam arising from the evaporation of the
spent leys in such boiler or other vessel utilized as a source of heat or other-
wise. The aforesaid furnace may also be connected with and furnish the heat
for the apparatus, herein-after described, which should be placed as near as
may be to the boiler or other vessel in question.
The apparatus referred to consists of a tower or other suitable arrangement
constructed of bricks, stone, or iron plates suitably supported, the external
form of which must be governed by convenience according to the nature of
the situation; it may, for example, consist of a vertical tower from 20 to 30
feet in height, oblong in shape, say 4 feet wide and 6 feet long; and inside
such tower I adapt or fix shelves or partitions of iron or other suitable
material (which may be corrugated to expose greater surface) placed at such
an inclination that liquor will flow down the same; the upper one of these
shelves is attached to one end, and to both sides of the tower, but does not
extend to the other end thereof, leaving an open space of from 4 to 6 inches;
the next shelf or partition is placed below this, and is attached to the opposite
end of the tower about 4 inches below the lower end of the shelf above, and
to the two sides of the tower it is placed at a similar inclination, but does not
extend to the other end of the tower, leaving as before a similar space of from
4 to 6 inches, and all the other shelves or partitions are similarly arranged;
a supply of liquor being introduced on the upper part of the first shelf flows
down from it to the next, and so on from shelf to shelf in thin films or sheets;
which may be regulated at will, and in its downward transit is exposed to an
upward current of air introduced to the lower portion of and drawn through
the tower by means of a chimney draft, fan, blast, suction, or other convenient
method. The tower may also have adapted to it at or near its lower part a
furnace or other apparatus of any well-known construction, suitable for the
production of a supply of heated air which may be drawn up or forced through
the tower by the aforesaid chimney draft, fan, blast, suction, or other con-
venient method; or the said current of heated air may be obtained from the
furnace attached to the boiler or other vessel for receiving the spent leys from
the boiling pans before referred to.
The tower may also instead of being fitted with the shelves or partitions as
above described, be furnished with layers or strata of broken stone, flints,
pottery, coke, or other suitable material through which the spent leys forced
or pumped up to the top of said tower may flow or trickle, exposed to the
upward current of air, heated or otherwise, as before mentioned. Or like

page_text: towers may be employed in which the leys are caused otherwise to descend in
showers or in minute division, meeting the upward currents of air.
And further should the situation of the works admit of such an arrange-
ment from being placed near elevated ground on which a chimney can be
conveniently erected, an inclined chamber or shoot constructed as the tower
of brick, stone, iron, or other suitable material, may be carried upwards any
convenient distance, furnished with shelves, corrugations, or ribs of iron, or
other suitable material down which the liquor previously forced or pumped up
to the top thereof may flow, meeting an upward current of air heated or other-
wise created by the said chimney draft, such current of air being kept down
to the surface of the descending liquor in a thin stratum from 4 to 6 inches,
and the said inclined chamber may be constructed of any convenient width.
As the spent leys or liquor flows down the tower or other arrangement they
are collected at the bottom thereof, and thence conveyed to the first receiving
boiler or vessel, or to another vessel, again heated, and again forced up to the
top of the tower, and so on until the liquor is sufficiently concentrated; or the
liquor may be cooled down and any crystallizable salts fished out; the liquor
may finallybe run into a reverberatory or boiling-down furnace of the ordinary
character employed for the manufacture of soda, there evaporated to dryness,
when the vegetable and resinous compounds retained in the leys will ignite,
giving out gaseous products which may be utilized as a source of heat, or
when reduced to a pasty mass drawn from the reverberatory or other furnace
and placed in a retort or still, and the said gaseous products collecting for
illuminating purposes. The resulting ash may then be lixiviated in the
ordinary manner, and the soda or other alkaline salts obtained therefrom as
practised with soda ash liquors or fresh leys for the process of boiling the
fibres obtained by boiling the resulting ash in water, adding sufficient lime in
the caustic state to deprive it of its carbonic acid, and the clear ley drawn off
for use in the usual manner.
In the ordinary process of treating fibrous material for paper stock when
hydrate or caustic soda is not employed for making the leys, soda ash, or soda
in the state of carbonate is employed, which is dissolved in water, and the
proper equivalent proportion of caustic or quick lime added thereto, the whole
boiled up together, and the resulting clear ley after settling, decanted, or
syphoned off for use, leaving the lime in the state of carbonate as a mud in
the bottom of the pan or other vessel in which the ley is made. This lime
mud contains both mechanically and chemically combined therewith a con-
siderable per-centage of alkali, which I propose to regain by first carefully
washing or filtering the lime mud, adding such liquor to the water used for

page_text: making the fresh leys, and then running the said lime mud into shallow pans
or vessels made of iron, brick, or other suitable material, the said pans-being
heated by the waste heat from any of the previous processes or otherwise to
abstract the excess of water therefrom, when the lime may be converted into
bricks or lumps and again burnt, and the carbonic acid driven off, and thus
converted again into caustic or quick lime, retaining the alkali combined
therewith, and the said lime like the alkali reclaimed from the spent leys, used
again and again in making fresh leys, or it may be added to the soda or other
alkali in the boiling down or calcining furnace, by this means avoiding to;a
great extent the cost of purchasing fresh lime, and also a fruitful source of
contamination of the stream now caused by running therein the limedrege
from the ley-making process.
d has
In witness whereof, I, the said Thomas Routledge, have hereunto set my
hand and seal, this Second day of August, in the year of our Lord
One thousand eight hundred and sixty-five.
..
miiod
L.S.
THOS. ROUTLEDGE. (S)
Pr. F. N. MILLER,
pil
His Attorneydo