IMPROVEMENTS IN THE MANUFACTURE OF PAPER FROM STRAW AND OTHER VEGETABLE SUBSTANCES."
Year: 1856

page_text: LETTERS PATENT to John Cowley, of Quenington, in the County of
Gloucester, for the Invention of "IMPROVEMENTS IN THE MANUFACTURE OF
PAPER FROM STRAW AND OTHER VEGETABLE SUBSTANCES."
PROVISIONAL SPECIFICATION left by the said John Cowley at the
Office of the Commissioners of Patents, with his Petition, on the
18th July 1856.
I, JOHN COWLEY, of Quenington, in the County of Gloucester, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN THE MANU-
FACTURE OF PAPER FROM STRAW AND OTHER VEGETABLE SUBSTANCES," to be as
follows:-
The object of my Invention is to convert straw and other similar vegetable
substances into paper with economy and despatch. The straw is first to be
cut into short lengths and placed in a vessel or "kier" constructed for the
purpose. This vessel must be fitted with a false bottom, leaving a space of
about six inches between. This is for the purpose of obtaining a rapid cir-
culation of the fluid. After the straw is placed in the kier it is submitted to
the action of. an alkaline liquor, prepared by dissolving caustic soda in water.
Six hundredweight of caustic soda boiled for about 20 minutes in 1,200
gallons of water will make a sufficient quantity of alkaline liquor for the
manufacture of one ton of paper. The alkaline liquor, as it flows from the
cistern or reservoir, passes through a coil of pipe fitted in a furnace, where
the temperature of the liquor is raised to about 300 degrees or more Fahren-

page_text: heit. The coil of pipe should be of a capacity to contain about 50 gallons
of liquor, and must be fitted with cocks or valves, that the quantity contained
in the cistern may be admitted to the coil in successive charges to be heated
to the required degree. The coil of pipe is carried up over the edge of the
kier, and terminates in the centre in a perforated spiral tube, by which the
liquor is distributed in jets over the surface of the straw. The liquor is
forced up the vertical pipe by the pressure of steam conveyed through a pipe
connected with a boiler. At the bottom of the kier is fitted a pipe which
conveys the alkaline liquor as it percolates through the straw into the coil to
be again heated, the admission of the liquor being regulated by a cock. The
operation of heating the successive charges of liquor must be repeated for
about eight or ten hous, until the straw is sufficiently boiled, which may be
known by testing it. To ensure a high and regular degree of heat in the
kier, a coil or coils of pipe are carried through the straw or round the interior
of the vessel, and connected with the upper and lower part of the boiler, so
that the condensed steam may be readily carried into the boiler. If a greater
degree of heat be required, superheated steam may be used. After boiling,
the straw is washed, then passed through a beating engine, and finally
bleached by the use of chlorine liquor.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Cowley in the Great Seal Patent Office on the
17th January 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
COWLEY, of Quenington, in the County of Gloucester, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eighteenth day of July, in the year of our Lord.
One thousand eight.hundred and fifty-six, in the twentieth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the
said John Cowley, Her special licence that I, the said John Cowley, my
executors, administrators, and assigns, or such others as I, the said John
Cowley, 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 THE
MANUFACTURE OF PAPER FROM STRAW. AND OTHER VEGETABLE SUBSTANCES," upon

page_text: the condition (amongst others) that I, the said John Cowley, my executors or
administrators, by an instrument in writing under his, 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 John Cowley, do hereby declare the
nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement:-
This Invention of improvements in the manufacture of paper from straw
and other vegetable substances consists chiefly of a particular arrangement of
apparatus by which the process of manufacturing paper from straw is greatly
expedited, at the same time the quality of the pulp is so much improved that
good paper, having a clear surface and excellent colour, may be made from
straw alone, which, as far as I am aware, has not hitherto been accomplished,
the ordinary practice being to mix a certain proportion of rag pulp with the
straw when making it into paper. The most important point in converting
straw into pulp is the judicious application of heat; and the principal object of
my Invention is the construction and application of an apparatus by means
of which the straw intended for pulp may be subjected to a very high degree
of temperature, and maintained thereat as long as requisite. The first
operation is to cut the straw into short lengths by means of a suitable
machine. The cut straw is then put into an iron vessel constructed for the
purpose. A circular vessel of twelve feet diameter by six feet in depth will
be found a convenient size in practice, such a vessel containing a sufficient
quantity of straw for the manufacture of two tons of paper. The vessel must
be fitted with a false bottom of about six inches in depth to allow of a rapid
circulation of the alkaline liquor with which the straw is saturated. In a
convenient position near to this vessel a furnace is built, in which a coil of
pipe, resting at an angle of forty-five degrees, is fitted, the ends of which
terminate in double branched pipes. The two branches of one of the ends
communicate respectively with a cistern or cisterns containing the alkaline
liquor, the other carries the alkaline liquor upward over the vessel, and dis-
tributes it through a spiral perforated coil over the surface of the straw. The
branches of the other end of the coil are carried into the bottom of the vessel
and into a boiler or suitable generator erected for the purpose. All these
pipes are furnished with taps and valves for the purpose of shutting off the

page_text: communication as required. A quantity of alkaline liquor having been pre-
pared, according to the directions herein-after contained, either in the cistern
or cisterns above referred to, or run into the same from some other vessel,
this alkaline liquor, when all is ready, is allowed to flow into the heated coil
in the furnace. The length of the coil should be calculated so that it contains
about fifty gallons of fluid. When the temperature of the liquor has reached
three hundred degrees of Fahrenheit, or thereabouts, the tap in the pipe
communicating with the boiler is turned on, and the pressure of the steam
causes the alkaline liquor to ascend the pipe which passes over the vessel,
and to rush through the perforations of the spiral tube. The whole of the
alkaline liquor is thus distributed over the straw, and when this is done the
tap at the bottom of the vessel is opened, and the steam cock shut. The
alkaline liquor which has percolated through the straw into the space below
the false bottom of the vessel now descends into the coil, and is there rapidly
reheated. The tap communicating with the bottom of the vessel is shut when
the coil is full. When the liquor has reached the proper temperature the
steam tap is again opened, and the liquor raised by the pressure of the steam.
This operation of heating and reheating the alkaline liquor being continued
until the straw is sufficiently macerated. If the temperature of the alkaline
liquor be maintained at three hundred degrees Fahrenheit, from six or eight
hours boiling will be sufficient to complete the operation. The heat com-
municated to the straw in the vessel may be further increased by means of
a pipe proceeding from a high pressure boiler, and terminating in a coil or
coils of perforated tubing, which passes through the straw in the vessel.
Thus steam of a high temperature may be circulated through the straw
whenever required, and an uniform degree of heat maintained throughout the
The straw is afterwards washed, and finally bleached; it is then ready
for the beating engine.
mass.
But in order that my Invention may be fully understood, I will proceed
to describe the apparatus and operations in detail, referring to the Drawings
accompanying and forming part of this Specification, and to the letters and
figures marked thereon.
In the first place, the straw is cut into short lengths of from one-fourth to
one-half of an inch in length, either by means of a powerful chaff-cutting
machine driven by steam power, or by a series of the ordinary chaff machines
actuated by steam or manual power. This part of the process may be per-
formed either upon an upper floor over the range of vessels, or the cut straw
may be carried up to the floor by chain buckets or other similar mechanical
contrivances, the object being to have a ready means of passing the straw

page_text: into the vessels; into which the straw may be carried either through suitable
shoots, or be allowed to fall through trap doors made in the flooring for the
purpose. Referring to the Drawing, which represents a side elevation partly
in section of the vessel for boiling the straw, and the heating apparatus con-
nected therewith, A is the vessel fitted with a false bottom a¹; B, B, are
cisterns or reservoirs for holding the alkaline liquor; C is a boiler or steam
generator; D, a coil of pipe fitted in a furnace E. One end of the coil com-
municated by means of the pipe F with the bottom of the cisterns B, the
communication being controlled by the tap f', near to which a branch pipe G
is fitted, which connects the coil with the spiral perforated tube H suspended
at the upper part of the vessel and over the surface of the straw. The other
end of the coil terminates in a pipe I connected with the bottom of the vessel
and a branch pipe K communicating with the boiler C. The pipes G, I, K,
are each fitted with taps 9', ', k', by which the communications may be opened
or shut as required. The coil of pipe D is fitted in the furnace at an angle
of about forty-five degrees, with a view of facilitating the ascent and escape of
the heated portions of the liquor. L is a steam pipe connecting the boiler C
with the tube or tubes M, M; this is for the purpose of conveying high
pressure steam into the vessel when required, the passage of the steam being
regulated by the cocks P, . By means of these pipes the steam may be
either made to circulate through the tube M, or be conveyed to the straw
through the perforated tube M'. From the lower part of the tube Ma
pipe N is carried down to the bottom of the boiler; this is for the purpose
of preventing the waste of steam, and conveying the condensed water (should
there be any) back into the boiler. When the steam is allowed to escape
through the perforated tube M', the tap n' must be kept shut. O is a
washing vessel placed in convenient proximity to the one in which the straw
is boiled. This vessel is fitted with a false bottom o¹, similar to that in the
iron vessel. P is an agitator actuated by the bevil wheel Q on the shaft q'.
This agitator is constructed upon an improved principle; the arms are divided
into two series, which are caused to rotate in opposite directions. The lower
series of arms P, P, are fitted to a casting R, which is secured to the
shaft R', and put in motion by the bevil wheel R³, which is in gear with the
driving wheel Q. The lower part of the shaft R¹ turns in a step or bearing
fitted to the bottom of the vessel; the upper part passes through the lower
part of the bracket S, and rotates in the bearing fitted at the upper part of
the bracket. The series of arms P³, P¹, is secured to the casting of the hollow
shaft T, to which is keyed the wheel T', which is actuated by the driving
wheel Q. By this arrangement of the driving gear the lower set of arms is

page_text: caused to rotate in one direction, while the upper set turns the contrary way.
This breaks up the mass of straw, and thoroughly agitates it; the object is
to prevent the straw being carried round in a body without being broken up,
thereby preventing the fluid in which it is immersed acting upon it. The
vessel for boiling the straw may be constructed of iron or other suitable
material. I give the preference, however, to that metal, and I have found
.the size herein-before named, that is to say, twelve feet diameter by six feet
.deep, to be the best in practice. The cisterns B are to be supplied with a
quantity of alkaline liquor prepared by dissolving four hundredweight of
_caustic soda or potass in twelve hundred gallons of water, and boiled for
twenty minutes. This quantity of liquor is sufficient to saturate the bulk of
straw necessary to produce one ton of paper. The cut straw is then put into
the iron vessel, and the fire in the furnace E having been lighted, so as to
raise the temperature of the coil D, the tap f¹ is opened, and the contents of
.the cistern B allowed to flow into the coil; the taps g¹ and are then opened,
⚫the pressure of steam forces the alkaline liquor up the pipe G and through the
perforations of the spiral tube H, by which it is distributed over the surface
of the straw. When the whole quantity of liquor in the cistern B has passed
through the coil D, the tap f may be shut, and i opened, by which the
alkaline liquor, as it percolates through the straw, flows beneath the false
bottom down the pipe I, and back into the coil to be reheated. And this
circulation must be kept up for six or eight hours, until the straw or other
.vegetable substance is sufficiently macerated, which may be known by testing.
The experienced workman will detect in a moment by the sense of touch
.whether the straw has been exposed a sufficient of time to the action of the
alkaline liquor. The object of the arrangement of the coil in a furnace is
that the temperature of the alkaline liquor may be raised considerably above
the ordinary boiling point. The temperature at which I prefer to maintain
the alkaline liquor before it leaves the coil in the furnace is about three
hundred degrees Fahrenheit. After the straw is sufficiently boiled, the alka-
line liquor is run off, and about two gallons of hydrochloric acid diluted with
twenty gallons of water is poured over the straw, the vessel is then filled up
with cold water until the straw floats. A cock at the bottom of the vessel is
then opened, and the water allowed to run to waste, still letting the steam of
cold water flow in until the straw is cooled. The water will also have the
effect of partially cleansing the straw of its colouring matter. When the
straw is sufficiently cooled it may be removed and placed in the washing
vessel O. As the straw is being removed to the washing vessel the agitator
is kept in motion, and cold water allowed to run through. This operation

page_text: will, in about ten minutes after the vessel is full, cleanse the straw of all
coloring matter, and if hot water be used the operation may be completed in
less time. The straw or other vegetable substance is now ready for bleaching.
A valve at the bottom of the washing vessel is opened, and the straw run into
a bleaching cistern U, in which is placed a sufficient quantity of bleaching
liquor to saturate the straw; the bleaching cistern or cisterns also fitted with
an agitator, and the action of stirring kept up for about six hours. If after
this time the straw is not perfectly bleached, the addition of a small quantity
of sulphate of alumina will complete the process. The use of the agitator is
to save labour. In many cases it may be desirable to render the bleaching.
liquor innocuous before allowing it to run to waste. This may be readily done
by heating it by a jet of steam to about two hundred degrees Fahrenheit,
which will cause the chlorine to be evolved, and render the liquor harmless
should it be allowed to run into a neighbouring stream; after emptying the
bleaching cistern of the liquor, the straw should be washed for five or ten
minutes with cold water, and it is then ready for the beating engine. The
foregoing process is equally applicable to any other vegetable substance suit-
able for the manufacture of paper besides straw; for example, flax, hemp,
jute, grasses of various kinds, and fibres of foreign plants. I may here
observe, that the addition of a small quantity of well bleached jute to the
straw will in some cases be found advantageous, for it imparts to the finished
paper a peculiar softness without injuring its color.
Having described the nature of my Invention, and the manner of carrying
the same into practical effect, I desire it to be understood that I do not
confine myself to the precise arrangement of the apparatus as herein-before
described, nor to the exact details of the process, as the same may be varied
without departing from the Invention; but what I claim, and desire to secure
under the herein-before in part recited Letters Patent, is, the preparation of
straw and other vegetable substances suitable to the manufacture of paper in
the manner herein-before described, and the use of the apparatus described
and shewn in and by this Specification for heating the alkaline liquors used in
the manufacture of paper from straw and other vegetable substances.
In witness whereof, I, the said John Cowley, have hereunto set my hand
and seal, this Seventeenth day of January, in the year of our Lord One
thousand eight hundred and fifty-seven.
JOHN COWLEY. (L.S.)