IMPROVEMENTS IN MEANS OR APPARATUS FOR THE MANUFACTURE OF PAPER PULP
Year: 1876

page_text: LETTERS PATENT to Nicholas Berriman Downing and John Edward Hughes,
of No. 4, Lambeth Hill, Queen Victoria Street, in the City of London,
Merchants, for the Invention of "IMPROVEMENTS IN MEANS OR APPARATUS
FOR THE MANUFACTURE OF PAPER PULP." A communication from abroad by
John Wesley Dixon, of West Manayunk, Montgomery County, in the State of
Pennsylvania. in the United States of America.
Scaled the 28th October 1876, and dated the 11th May 1876.
PROVISIONAL SPECIFICATION left by the said Nicholas Berriman Downing
and John Edward Hughes at the Office of the Commissioners of Patents on
the 11th May 1870.
NICHOLAS BERRIMAN DOWNING and JOHN EDWARD HUGHES, of No. 4, Lambeth
"IMPROVEMENTS
Hill, Queen Victoria Street, in the City of London, Merchants.
IN MEANS OR APPARATUS FOR THE MANUFACTURE OF PAPER PULP." A communi-
cation from from abroad by John Wesley Dixon, of West Manayunk, Montgomery
County, in the State of Pennsylvania, in the United States of America.
This Invention relates to improved means or apparatus for the reduction of
paper pulp from wood, straw, or other vegetable fibre.
In carrying out the Invention a digester for reducing the paper pulp is employed
provided with an upper and a lower perforated diaphragm, between which diaphragms,
through suitable openings capable of being closed when desired formed in the
upper part of the digester and in this upper diaphragm, the "stock," wood, straw,
or other vegetable fibre is introduced in order to its being acted upon by the
alkaline solution or liquor. This liquor is poured thereon through the openings in
the digester and upper diaphragm described until the stock is covered or the
digester is nearly full. These openings are then closed as well as another opening
at the lower part of the digester above the lower diaphragm provided for the exit
of the stock when desired. Connection is now opened into a pipe leading from
the bottom of the digester below the lower diaphragm to a fan pump driven by
suitable driving means by which the liquor flowing from the digester is forced
through suitable piping to a coil or coils, or chamber or chambers placed within a
steam boiler or heating vessel. This steam boiler may be formed in two sections,
[Price Gd.1

page_text: the chamber or chambers for heating the alkaline liquor being placed in the upper
one.
The liquor is highly heated in the course of its passage through the coil or
chamber or chambers from the digester by contact thereof with the steam or hot
water of the boiler, and is thence conducted through another opening into the
upper part of the digester, and through the upper perforated diaphragm, and the
contained " stock," and through the lower diaphragm to the lower part of the
digester, and by the pipe communicating with the fan pump is again forced to
the heating coil, or chamber or chambers in the boiler to be licated again, and
Bo on. By these means a continuous circulation is kept up by the fan pump driving
forward the liquor as it flows from the digester, obviating a difficulty heretofore
experienced from the suction of the fine pulp into the openings of the lower
diaphragm of the digester and the consequent prevention of the circulation of the
liquor, and the coil or chamber is not subjected to the direct burning effect of
the furnace fire nor its contents to danger of evaporation from the intense heat
of the fire, and other advantages are obtained.
In some cases hot air may be employed in place of steam, or hot water to beat
the alkaline liquor in the coil or chambers.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by the
said Nicholas Berriman Downing and John Edward Hughes in the Great
Scal Patent Office on the 11th November 1876.
NICHOLAS BERRIMAN DOWNING and JOHN EDWARD HUGHES, of No. 4 Lambeth
Hill, Queen Victoria Street, in the City of London, Merchants. "IMPROVEMENTS
IN MEANS OR APPARATUS FOR THE MANUFACTURE OF PAPER PULP." A communi-
cation from abroad by John Wesley Dixon, of West Manayunk, Montgomery
County, in the State of Pennsylvania, in the United States of America.
This Invention relates to improved incans or apparatus for the reduction of paper
pulp from wood, straw, or other vegetable fibre.
In carrying out the Invention a digester for reducing the paper pulp is employed
provided with an upper and a lower perforated diaphragm, between which dia-
phragms, through suitable openings capable of being closed when desired formed
in the upper part of the digester and in this upper diaphragmn, the "stock," wood,
straw, or other vegetable fibre is introduced in order to its being acted upon by the
alkaline solution or liquor. This liquor is poured thereon through the openings in
the digester and upper diaphragın described, until the stock is covered or the
digester is nearly full. These openings are then closed as well as another opening
nt the lower part of the digester above the lower diaphragın provided for the exit
of the stock when desired. Connection is now opened into a pipe leading from the
bottom of the digester below the lower diaphragm to a fan pump driven by suitable
driving means by which the liquor flowing from the digester is forced through
suitable piping to a coil or coils or chamber or chambers placed within a steam
boiler or heating vessel. This steam boiler may be formed in two sections, the
chamber or chambers for heating the alkaline liquor being placed in the upper one.
The liquor is highly heated in the course of its passage through the coil or
chamber or chambers from the digester by contact thereof with the steam or hot
water of the boiler, and is thence conducted through another opening into the
upper part of the digester, and through the upper perforated diaphragm and the
contained "stock," and through the lower diaphragm to the lower part of
the digester, and by the pipe communicating with the fan pump is again forced
to the heating coil or chamber or chambers in the boiler to be heated again, and so
on. By these means a continuous circulation is kept up by the fan pump driving
forward the liquor as it flows from the digester, obviating a difficulty heretofore
experienced from the suction of the fine pulp into the openings of the lower

page_text: DESCRIPTION OF THE DRAWINGS.
Figure 1 is a vertical longitudinal section of the two sections of steam boiler, in
the upper one of which the coil for heating the alkaline liquor is situated; Figure 2
a similar view of the digester connecting parts of the coil of pipe and the fan pump,
also showing Figure 1 in elevation.
A is the pulp digester; B, B', the two sections of the steam boiler; C, C¹, C,
the connections of the coil of pipe C with the digester; D, the fan pump located
between pipes C and C¹; E, pulley for driving the pump D; F, the furnace for
heating the steam boilers; G, the tubes of tubular boiler B; H, a cock; I, J, lower
and upper perforated diaphragms in the digester A, and which contain the stock to
be reduced between them. This stock, wood, straw, or other vegetable fibre is
introduced through a man-holo in the upper diaphragm J, and finds exit through
the opening K, which is secured closed by a valvo or cock. In practice the lower
diaphragm I is slanted toward the opening K to facilitate the removal of the pulp
after the operation is complete; L is a cock to stop the flow of the alkaline liquor
into coil Cl
The apparatus is operated as follows:-The stock, wood, or straw, or other
vegetable fibre to be reduced to paper pulp is introduced into the digester A
between diaphragms I and J through the opening in the top of the digester, and
the man-hole opening in the diaphragm J. The exit opening K should of course
have first been closed. The alkaline solution or liquor is then poured into the
digester on the stock until the stock is covered or the digester nearly full. The
man-hole in the diaphragm J is then closed, and the top of the digester also.
The cock for the supply of the liquor L being open, will then have filled pipe C₁
to the height of the liquor in the digester. The boilers B', B', (which in many cases
would be the ordinary steam boilers employed in actuating the motive parts of the
machinery of the paper mill) are then steamed up, and the coil of pipe C in boiler B
is thus heated by contact with the steam and hot water therein. The fan pump D
is then started by the belt on pulley E, and the alkaliue liquor is thus projected
through the pipe C into the coil C in the boiler, being highly heated in its
passage through the latter, thence through open cock H into the digester through
the diaphragm J, and the inner contained stock through diaphragm I, and open
cock Lon pipe C to the fan pump D, to be once more projected through the coil.
The great body of the alkaline liquor makes this operation continuous. Thus a
continuous circulation is kept up. The pump D, being a fan pump, simply drives
forward such liquor as flows into it from the digester, thus obvinting a difficulty
heretofore experienced, viz., the suction of the fine pulp into the openings of the
lower diaphragm I of the digester, and the consequent provention of the circulation
of the liquor.
The difficulties beretoforo experienced in reducing stock to pulp by this general
process in addition to that named in the latter end of the last paragraph have been
as follows:-The coil C" used to heat the alkalino liquor in its passage through it
has been beated by the direct fire of a furnace beneath it. When coal was thrown
on to this fire the pipes became cooled, and when the heat came up the lower part
of the coil was often so highly heated that its contents were converted into steam,
the pressure of which drove back the incoming liquid, requiring very heavy and

page_text: expensive coils of pipe to withstand its steam pressure, and the lime and soda in
solution in it was also left deposited in the coil; precipitated by the evaporation
of the absorbent liquid, so the pipes were sometimes filled up by this Lurnt and
caked sediment. By the means which we have described, however, the surplus licat
engendered in the water of the steam boilers by the coil Cu immersed therein
can be economized thus, also using but one furnace to heat both the steam boilers
and the coil C, but whether the coil is thus placed in the steam boiler or a special
tank or boiler and furnace is provided for it, the heating by immersion in hot
water or steam still possesses these advantages, viz., that the coil is not subjected
to the direct burning effect of the furnace fire, and cannot, therefore, be easily
burned up, nor are its contents subjected to the danger of evaporation from the
intense heat of a white fire. Again, in coaling up the furnace, the water retains
the heat required until the combustion of the new coal renews and sustains the
supply. Thus lighter and less costly coils can be used, and uniform temperature
both of the coil and the liquor in the digester sustained.
The conversion of the alkalino liquor into steam by heat of a direct fire on the
coil also produces a top pressure of steam in the upper end of digester A, thus
compressing the mass of pulp between the diaphragms down upon the lower
diaphragm I, choking it up and rendering free circulation impossible. This dis-
advantage is removed by the use of these improvements.
The coil C can be supplanted by a section of straight pipes or small chambers
or other device suitable for the purpose, and an equivalent of the coil, and this
cail can be heated by hot air instead of steam or hot water, the former being an
equivalent of the two latter.
Having thus described the Invention, and what we claim as new, and desiru to
securo by Letters Patent is-
First. In combination with the digester A, the chamber B and a coil or chamber
within the same, whereby the alkaline solution in its passage to the digester
through said coil or chamber is heated by means of steam or hot water in said
chamber, substantially as described.
Second. The combination of the digester and the heating coil or chamber with
the intermediate fan pump, whereby the alkaline solution is driven through the
said coil or chamber without being sucked from the digester, substantially as
described.
In witness whereof, I, the said John Edward Hughes, have hereunto set my
hand and scal, this Ninth day of November, in the year of our Lord One
thousand night hundred and saventy-six
J. E. HUGHES. (L.S.)